Sample records for taiga soils

  1. Initial data on biological activity of taiga-steppe soils in the lower reaches of the Kolyma River.

    PubMed

    Schelchkova, M V; Davydov, S P; Fyodorov-Davydov, D G; Davydova, A I; Boeskorov, G G; Solomonov, N G

    2017-11-01

    Microbiological and enzyme activities of extrazonal taiga-steppe soils in the lower reaches of the Kolyma River have been studied for the first time. Contrary to north-taiga cryometamorphic soils, predominating in the area, microbial cenoses under herb-sedge petrophytic and grass-sagebrush-herb thermophytic steppes are characterized by features typical for arid soils. The saturation of the soil profile with microorganisms is greater, and the development of actinomycetes is more intensive. The enzyme complex is characterized by high activity of dehydrogenases.

  2. Unconsidered sporadic sources of carbon dioxide emission from soils in taiga forests.

    PubMed

    Karelin, D V; Zamolodchikov, D G; Isaev, A S

    2017-07-01

    Long-term monitoring in the Russian taiga zone has shown that all known extreme destructive effects resulting in the weakening and death of tree stands (windfalls, pest attacks, drought events, etc.) can be sporadic, but significant sources of CO 2 soil emission. Among them are (i) a recently found effect of the multiyear CO 2 emission from soil at the bottom of deadwood of spruce trees that died due to climate warming and subsequent pest outbreaks, (ii) increased soil CO 2 emissions due to to the fall of tree trunks during massive windfalls, and (iii) pulse CO 2 emission as a result of the so-called Birch effect after drought events in the taiga zone. According to the modeling, while depending on the spatial and temporal scales of their manifestation, the impact of these sporadic effects on the regional and global soil respiration fluxes could be significant and should be taken into consideration. This is due to continuing Climate Change, and further increase of local, regional and Global human impacts on the atmospheric greenhouse gases balance, and land use, as well.

  3. Water-soluble low-molecular-weight organic acids in automorphic loamy soils of the tundra and taiga zones

    NASA Astrophysics Data System (ADS)

    Shamrikova, E. V.; Gruzdev, I. V.; Punegov, V. V.; Khabibullina, F. M.; Kubik, O. S.

    2013-06-01

    The formation features of water-soluble low-molecular-weight organic acids (LMWOAs) in a zonal series of automorphic soils on loose silicate rocks from the middle taiga to the southern tundra (typical podzolic, gley-podzolic, and surface-gley tundra soils) were first revealed by gas chromatography mass spectrometry and gas-liquid chromatography. The content of LMWOAs varies within the range of 1-14 mg/dm3, which corresponds to 1-5% of the total carbon of the water-soluble soil organic matter. It has been shown that a subzonal feature of gley-podzolic soils in the northern taiga is the high content of LMWOAs, including primarily the strongest aliphatic hydroxyl acids. Possible mechanisms of their formation and accumulation in soils have been considered.

  4. Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia.

    PubMed

    Kalinina, Olga; Goryachkin, Sergey V; Karavaeva, Nina A; Lyuri, Dmitriy I; Giani, Luise

    2010-04-26

    Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization. A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition. The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration.

  5. Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia

    PubMed Central

    2010-01-01

    Background Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization. Results A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition. Conclusion The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration. PMID:20420668

  6. Comparative Analysis of the Number and Structure of the Complexes of Microscopic Fungi in Tundra and Taiga Soils in the North of the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Korneikova, M. V.

    2018-01-01

    The number, biomass, length of fungal mycelium, and species diversity of microscopic fungi have been studied in soils of the tundra and taiga zones in the northern part of the Kola Peninsula: Al-Fe-humus podzols (Albic Podzols), podburs (Entic Podzols), dry peaty soils (Folic Histosols), low-moor peat soils (Sapric Histosols), and soils of frost bare spots (Cryosols). The number of cultivated microscopic fungi in tundra soils varied from 8 to 328 thousand CFU/g, their biomass averaged 1.81 ± 0.19 mg/g, and the length of fungal mycelium averaged 245 ± 25 m/g. The number of micromycetes in taiga soils varied from 80 to 350 thousand CFU/g, the number of fungal propagules in some years reached 600 thousand CFU/g; the fungal biomass varied from 0.23 to 6.2 mg/g, and the length of fungal mycelium varied from 32 to 3900 m/g. Overall, 36 species of fungi belonging to 16 genera, 13 families, and 8 orders were isolated from tundra soils. The species diversity of microscopic fungi in taiga soils was significantly higher: 87 species belonging to 31 genera, 21 families, and 11 orders. Fungi from the Penicillium genus predominated in both natural zones and constituted 38-50% of the total number of isolated species. The soils of tundra and taiga zones were characterized by their own complexes of micromycetes; the similarity of their species composition was about 40%. In soils of the tundra zone, Mortierella longicollis, Penicillium melinii, P. raistrickii, and P. simplicissimum predominated; dominant fungal species in soils of the taiga zone were represented by M. longicollis, P. decumbens, P. implicatum, and Umbelopsis isabellina.

  7. Artificial and natural radionuclides in soils of the southern and middle taiga zones of Komi Republic

    NASA Astrophysics Data System (ADS)

    Beznosikov, V. A.; Lodygin, E. D.; Shuktomova, I. I.

    2017-07-01

    Specific activities of artificial (137Cs, 90Sr) and natural (40K, 232Th, 226Ra) radionuclides in background soils of southern and middle taiga of Komi Republic have been estimated with consideration for the landscape-geochemical features of the territory. It has been shown that their accumulation and migration in soils are determined by the following factors: position in relief, texture, and organic matter content. No anomalous zones with increased contents of radionuclides in soils have been revealed.

  8. Agrogenic transformation of soil organic C in conditions of southern-taiga zone, European Russia

    NASA Astrophysics Data System (ADS)

    Yashin, Ivan; Vasenev, Ivan; Atenbekov, Ramiz

    2017-04-01

    The principal regional features of soil organic carbon (SOC) agrogenic transformation and water-soluble organic substances (WSOS) genesis and environmental functions have been investigated in the Podzols and Podzoluvisols of the representative natural and agro- ecosystems in the southern taiga subzone of the European part of Russia. Especial attention has been done to the role of SOC agrogenic degradation and WSOS with acidic and ligand properties in soil carbon dioxide emission. The long-term agroecological investigations run in the regional set of representative agrolandscape monitoring stations in the educational farm "Mikhailovskoye" (Podolsk district, Moscow region), Field experimental station and Forest experimental station (RTSAU campus, Moscow) and in the Central Forest biosphere reserve (Nelidovo district, Tver region). Field research methods include sorption lysimetry and radioactive tracers. The laboratory ones - chromatography and spectrophotometry. There were used activated charcoal brand "Carbolite", chemically purified quartz sand and barley plant residues (2-3 mm), totally labeled with 14C in the soil-horizontally distributed sorption columns. Obtained results became useful for quantitative assessment of the principal stages and processes in soil CO2 emission, including the water-soluble organic substances formation (3.0 g of SOC per 100 g of plant litter or 60-75 g of SOC per square meter of the organo-mineral horizon A0 per year) and CO2 emission. In the middle taiga ecosystem conditions (with relatively low soil biological activity) the highest emission of CO2 (83,0±4.1 % of the newly formed WSOS) was in case of arable Podzoluvisols, and lowest one (32,4±2,5%) - in their semihydromorphic versions.

  9. [Diversity of soil mesofauna in Northern Taiga biogeocenosises of the Kamennaya river basin (Karelia)].

    PubMed

    Rybalov, L B; Kamaev, I O

    2011-01-01

    The population of soil mesofauna in the basin of the small river subzone of the northern taiga (Karelia) has been investigated. It was shown that indexes of the number and mass of soil mesofauna in the landscape-ecological row ofbiogeocenosises are maximal in floodplain soils. The taxonomic composition and structure of domination of the soil mesofauna population depends on the location of biogeocenosis in the landscape: earthworms are dominants in riverine floodplain biogeocenosises, and larvae of elaterids and spiders prevail in the places outside of floodplains. The abundance of saprophytic invertebrates in floodplain biogeocenosises results in formation of humus of the mull type. A group of animals with mixed type of nutrition dominates in the places outside of floodplain soils that are related with humus of the moder-mor type. The population of rove beetles (Staphylinidae) allows the division of biogeocenosises into two groups according to their position in the landscape.

  10. Irreverent Soils: Nitrogen Dynamics In Taiga Forests During Winter

    NASA Astrophysics Data System (ADS)

    Kielland, K.

    2003-12-01

    We measured annual net nitrogen mineralization, nitrification, and amino acid production in situ across a primary successional sequence in interior Alaska, USA. Net N mineralization rates during the growing season from green-up (late May) through freeze-up (late September) accounted for approximately 60% of the annual inorganic N flux, whereas the remaining N was released during the apparent dormant season. Nitrogen release during winter occurred primarily during October-January with only negligible N mineralization during early spring in stands of willow, alder, balsam poplar and white spruce. By contrast, black spruce stands also exhibited substantial mineralization after snow melt during early spring. The high rates of N mineralization in late autumn through early winter coincides with high turnover of fine root biomass in these stands, suggesting that labile substrate production, rather than temperature, is a major controlling factor over N release in these ecosystems. The results are consistent with the low temperature sensitivity of N mineralization previously documented for taiga soils, and demonstrate that measurements of soil processes restricted to the growing season may greatly underestimate annual flux rates of inorganic nitrogen in high-latitude ecosystems.

  11. Soil catenas on denudation plains in the forest-tundra and northern taiga zones of the Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Urusevskaya, I. S.

    2017-07-01

    Morphogenetic features of soils of two catenas developed on sandy to loamy sandy moraine deposits in the forest-tundra and northern taiga zones on denudation plains of the Kola Peninsula are discussed. It is shown that these catenas are similar with respect to the major directions of soil formation, regularities of soil distribution by the elements of mesotopography, and the factors of the soil cover differentiation. The differences between the catenas are of quantitative character and are related to the intensities of manifestation of the particular processes and features. Both catenas are characterized by the pronounced differentiation of soils with respect to their moistening with hydromorphic peat bog soils in the subordinate positions and Al-Fe-humus podzols in the automorphic positions.

  12. Microbial activity in Alaskan taiga soils contaminated by crude oil in 1976

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Monroe, E.M.; Lindstrom, J.E.; Brown, E.J.

    1995-12-31

    Biodegradation, often measured via microbial activity, includes destruction of environmental pollutants by living microorganisms and is dependent upon many physical and chemical factors. Effects of mineral nutrients and organic matter on biodegradation of Prudhoe Bay crude oil were investigated at a nineteen-year-old oil spill site in Alaskan taiga. Microcosms of two different soil types from the spill site; one undeveloped soil with forest litter and detritus (O horizon) and one more developed with lower organic content (A horizon), were treated with various nitrogen and phosphorus amendments, and incubated for up to six weeks. Each microcosm was sampled periodically and assayedmore » for hydrocarbon mineralization potential using radiorespirometry, for total carbon dioxide respired using gas chromatography, and for numbers of hydrocarbon-degrading bacteria and heterotrophic bacteria using most probable number counting techniques. Organic matter in the O horizon soil along with combinations of mineral nutrients were found to stimulate microbial activity. No combination of mineral nutrient additions to the A horizon soil stimulated any of the parameters above those measured in control microcosms. The results of this study indicate that adding mineral nutrients and tilling the O horizon into the A horizon of subarctic soils contaminated with crude oil, would stimulate microbial activity, and therefore the biodegradation potential, ultimately increasing the rate of destruction of crude oil in these soils.« less

  13. The mesofauna in different types of soils under southern taiga spruce forests (Tver oblast)

    NASA Astrophysics Data System (ADS)

    Gryuntal, S. Yu.

    2010-11-01

    The soil mesofauna of the burozem, soddy pale-podzolic, and whitish-podzolic soils under three types of southern taiga spruce forests was studied. The mesofauna of all these soils turned out to be similar in terms of the Chilopoda, Staphylinidae (Coleoptera), and Rhagionidae (Diptera) numbers and their predominant concentration in the litter. The zoophages prevailed, and, among the saprophages, primary destroyers were predominant. However, some specific characteristics of the mesofauna in the soils studied were revealed. In the sequence burozem, soddy pale-podzolic, and whitish-podzolic soils, the number of earthworms significantly decreased, while, in the sequence soddy pale-podzolic, burozem, and whitish-podzolic soils, the number of Diplopoda representatives and calciphilic forms became lower and was directly related to the diversity of the deciduous tree species and to the presence of the calcareous moraine close to the surface. In addition, some species can be indicators of particular soil properties. The presence of the road beetle Quedius fuliginosus indicated the elevated moisture of the soils, that of Philonthus decorus pointed to the high humus content, and the presence of the road beetle Tachinus marginellus showed the low acidity of the humus. The low number or the absence of the earthworms Octolasium lacteum and Dendrodril us rubidus f. tenuis indicated higher humus acidity.

  14. TAIGA experiment: present status and perspectives

    NASA Astrophysics Data System (ADS)

    Budnev, N.; Astapov, I.; Bezyazeekov, P.; Boreyko, V.; Borodin, A.; Brückner, M.; Chiavassa, A.; Gafarov, A.; Grebenyuk, V.; Gress, O.; Gress, T.; Grinyuk, A.; Grishin, O.; Dyachok, A.; Fedorov, O.; Haungs, A.; Horns, D.; Huege, T.; Ivanova, A.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Kostunin, D.; Korosteleva, E.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Kuzmichev, L.; Lemeshev, Yu.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Osipova, E.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Poleschuk, V.; Popesku, M.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Petrukhin, A.; Pushnin, A.; Rjabov, E.; Rubtsov, G.; Sagan, Y.; Samoliga, V.; Semeney, Yu.; Sidorenkov, A.; Schröder, F.; Silaev, A.; Silaev (junior, A.; Skurikhin, A.; Slunecka, M.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Wischnewski, R.; Yashin, I.; Zagorodnikov, A.; Zhurov, D.; Zurbanov, V.

    2017-08-01

    The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV . TAIGA will be located in the Tunka valley, ~ 50 km West from Lake Baikal. The different detectors of the TAIGA will be grouped in 6 arrays to measure Cherenkov and radio emission as well as electron and muon components of atmospheric showers. The combination of the wide angle Cherenkov detectors of the TAIGA-HiSCORE array and the 4-m Imaging Atmospheric Cherenkov Telescopes of the TAIGA-IACT array with their FoV of 10×10 degrees and underground muon detectors offers a very cost effective way to construct a 5 km2 array for gamma-ray astronomy.

  15. [Soil functioning in foci of Siberian moth population outbreaks in the southern taiga subzone of Central Siberia].

    PubMed

    Krasnoshchekov, Iu N; Beskorovaĭnaia, I N

    2008-01-01

    The results of experimental studies on the contribution of zoogenic debris to transformation of soil properties in the southern taiga subzone of Central Siberia are analyzed. They show that water-soluble carbon outflow from the forest litter increases by 21-26% upon a Siberian moth invasion, with this value decreasing to 14% one year later. The burning of forest in an area completely defoliated by the pest leads to changes in the stock, fractional composition, actual acidity, and ash element contents of the litter. The litter-dwelling invertebrate assemblage is almost completely destroyed by fire and begins to recover only after two years.

  16. Soils in seasonally flooded forests as methane sources: A case study of West Siberian South taiga

    NASA Astrophysics Data System (ADS)

    Mochenov, S. Yu; Churkina, A. I.; Sabrekov, S. F.; Glagolev, M. V.; Il’yasov, D. V.; Terentieva, I. E.; Maksyutov, S. S.

    2018-03-01

    In this study, we measured the methane and carbon dioxide fluxes by static chamber method from the soil of periodically flooded forests under different water table levels (WTL) in West Siberian south taiga (Tomsk oblast, Russia) in summer seasons of 2016 and 2017 years. The study shows that seasonally flooded forests may become a methane source when the WTL increases up to 15-45 cm below the surface. The fluxes of methane from soil were from -0.08±0.07 to 9.3±0.8 mg·m-2·h-1, from 0.05±0. 04 to 0.14±0.13 mg·m-2·h-1, from - 0.03±0.02 to 5.4±0.2 mg·m-2·h-1 depending on variou s WTL in different seasonally flooded forests in 2017.

  17. How will the tundra-taiga interface respond to climate change?

    PubMed

    Skre, Oddvar; Baxter, Robert; Crawford, Robert M M; Callaghan, Terry V; Fedorkov, Alexey

    2002-08-01

    The intuitive and logical answer to the question of how the tundra-taiga interface will react to global warming is that it should move north and this is mirrored by many models of potential treeline migration. Northward movement may be the eventual outcome if climatic warming persists over centuries or millennia. However, closer examination of the tundra-taiga interface across its circumpolar extent reveals a more complex situation. The regional climatic history of the tundra-taiga interface is highly varied, and consequently it is to be expected that the forest tundra boundary zone will respond differently to climate change depending on local variations in climate, evolutionary history, soil development, and hydrology. Investigations reveal considerable stability at present in the position of the treeline and while there may be a long-term advance northwards there are oceanic regions where climatic warming may result in a retreat southwards due to increased bog development. Reinforcing this trend is an increasing human impact, particularly in the forest tundra of Russia, which forces the limit of the forested areas southwards. Local variations will therefore require continued observation and research, as they will be of considerable importance economically as well as for ecology and conservation.

  18. Carbon emission from the soil surface in a mature blueberry pine forest of the middle taiga (Republic of Komi)

    NASA Astrophysics Data System (ADS)

    Osipov, A. F.

    2016-08-01

    Data on the input of plant falloff and organic matter decomposition on the surface of the peaty podzolic-gleyic humus-illuvial (Gleyic Podzol) soil under a mature blueberry pine forest in the middle taiga are presented. The fractional composition of the falloff was determined, and constants of decomposition for its components were calculated. The carbon flux to the atmosphere due to the mineralization of plant residues is estimated at 251 g/m2. A close positive correlation ( r = 0.71; P < 0.05) was found between the carbon dioxide emission measured using a gas analyzer and the soil temperature at the depth of 10 cm. The CO2 emission for a growing period calculated from the data on its dependence on soil temperature in different years varied from 243 to 313 g C/m2 and was related to weather conditions.

  19. Acid-base buffering of soils in transitional and transitional-accumulative positions of undisturbed southern-taiga landscapes

    NASA Astrophysics Data System (ADS)

    Rusakova, E. S.; Ishkova, I. V.; Tolpeshta, I. I.; Sokolova, T. A.

    2012-05-01

    The method of continuous potentiometric titration (CPT) of soil water suspensions was used to evaluate the acid-base buffering of samples from the major genetic horizons of podzolic soils on a slope and soddy gley soils on the adjacent floodplain of a rivulet. In the soils of the slope, the buffering to acid upon titration from the pH of the initial titration point (ITP) to pH 3 in all the horizons was 1.5-2.0 times lower than that in the podzolic soils of the leveled interfluve, which could be due to the active leaching of exchangeable bases and oxalate-soluble aluminum and iron compounds with the later soil flows. In the soddy gley soils, the buffering to acid in the mineral horizons was 2-10 times higher than that in the podzolic soils. A direct dependence of the soil buffering to acid on the total content of exchangeable bases and on the content of oxalate-soluble aluminum compounds was found. A direct dependence of the buffering to basic upon titration from the ITP to pH 10 on the contents of the oxalate-soluble aluminum and organic matter was observed in the mineral horizons of all the studied soils. The soil treatment with Tamm's reagent resulted in the decrease of the buffering to acid in the soddy gley soils of the floodplain, as well as in the decrease of the buffering to basic in the soils on the slopes and in the soddy gley soils. It was also found that the redistribution of the mobile aluminum compounds between the eluvial, transitional, and transitional-accumulative positions in the undisturbed southern taiga landscapes leads to significant spatial differentiation of the acid-base buffering of the mineral soil horizons with a considerable increase in the buffer capacity of the soils within the transitional-accumulative terrain positions.

  20. Multi-Sensor Approach for Assessing the Taiga-Tundra Boundary

    NASA Technical Reports Server (NTRS)

    Ranson, K. J.; Sun, G.; Kharuk, V. I.; Kovacs, K.

    2003-01-01

    Monitoring the dynamics of the tundra-taiga boundary is critical for our understanding of the causes and consequences of the changes in this area. Because of its inaccessibility, remote sensing data will play an important role. In this study we examined the use of several remote sensing techniques for identifying the existing tundra-taiga ecotone. These include Landsat, MISR and RADARSAT data. High-resolution IKONOS images were used for local ground truth. It was found that on Landsat ETM+ summer images, reflectance from tundra and taiga at band 4 (NIR) is similar, but different at other bands such as red, and MIR bands. When the incidence angle is small, C-band HH-pol backscattering coefficients from both tundra and taiga are relatively high. The backscattering from tundra targets decreases faster than taiga targets when the incidence angle increases, because the tundra targets look smoother than taiga. Because of the shading effect of the vegetation, the MISR data, both multi-spectral data at nadir looking and multi-angle data at red and NIR bands, clearly show the transition zone.

  1. Geochemical studies of northern taiga (gypsum) karst ecosystems and their high vulnerability to natural and anthropogenic hazards

    NASA Astrophysics Data System (ADS)

    Tuyukina, T. Yu.

    2009-07-01

    In the taiga gypsum karst ecosystems, gypsum soils formed on the hard gypsum substrates predominate in the soil cover. In these soils, the mineral horizons consist of 95-99% gypsum (CaSO4·2H2O) and the litter is the main horizon for nutrient accumulation. For this reason, the ecosystems are vulnerable to fire and erosion by walkers, from which they only recover slowly. Gypsum mining for industrial uses is also leading to the destruction of this unique ecosystem.

  2. Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).

    NASA Astrophysics Data System (ADS)

    Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.

    2012-04-01

    Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation

  3. Specific features of the development of soils of hydromorphic ecosystems in the northern taiga of Western Siberia under conditions of cryogenesis

    NASA Astrophysics Data System (ADS)

    Matyshak, G. V.; Bogatyrev, L. G.; Goncharova, O. Yu.; Bobrik, A. A.

    2017-10-01

    Differently directed and heterochronous cryogenic processes have contributed to the contrasting soil cover patterns and spatial heterogeneity of the properties of soils in hydromorphic ecosystems of the discontinuous permafrost zone of the northern taiga in Western Siberia. Frost heave and permafrost thawing within ecosystems of highmoor bogs have led to the development of specific cryogenic landforms, such as flat-topped and large peat mounds. A set of cryogenic soils is developed in these ecosystems; it includes different variants of cryozems, gleyzems (Cryosols), and peat soils (Histosols). The distribution of these soil types is controlled by the local topography and thawing depth, other factors being insignificant. Alternation of peat horizons of different types and ages, whirl-like patterns of horizon boundaries, considerable variations in the thickness of soil horizons, and inversions of soil horizons under the impact of frost cracking, frost heave, and cryoturbation are typical of the considered soils. Thawing depth is the most significant factor affecting the thickness of organic horizons, the soil pH, and the degree of decomposition of peat. As a result of the upward movement of bog ecosystems under the impact of frost heave, peat soils are subjected to considerable transformation: peat horizons undergo mineralization, and the thickness of organic horizons decreases; in some cases, eluvial-illuvial differentiation of the mineral horizons takes place, and peat podzols are developed. However, the opposite process of the return of the soils to the bog stage of pedogenesis with peat accumulation may take place in any time in the case of activation of thermokarst processes.

  4. Forest ecosystems in the Alaskan taiga

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Van Cleve, K.; Chapin, F.S. III; Flanagan, P.W.

    1986-01-01

    This volume in the series ''Ecological Studies'' provides an overview and synthesis of research on the structure and function of taiga forest ecosystems of interior Alaska. The first section discusses the nature of the taiga environment and covers climate, forest ecosystem distribution, natural regeneration of vegetation, and the role of fire. The second edition focuses on environmental controls over organism activity with discussions on growth and nutrient use, nitrogen fixation, physiological ecology of mosses, and microbial activity and element availability. The final section considers environmental controls over ecosystem processes with discussions of processes, plant-animal interactions, and a model of forestmore » growth and yield.« less

  5. Features of seasonal temperature variations in peat soils of oligotrophic bogs in south taiga of Western Siberia

    NASA Astrophysics Data System (ADS)

    Kiselev, M. V.; Dyukarev, E. A.; Voropay, N. N.

    2018-03-01

    The work presents the results of the study of the peculiarities of the temperature regime in the five basic ecosystems of oligotrophic bogs in the south taiga zone of Western Siberia in 2011-2016. The soil temperature regime was studied using the atmospheric-soil measuring complex at different depths from surface down to 240 cm. All sites were divided into two groups according to the bog water level: flooded sites (hollow and open fen) and drained sites (ridge, tall and low ryam). The waterlogged sites are better warmed in the summer period and slowly freeze in the winter period. The analysis of the annual cycle of temperature showed that the maximum surface temperature is in July. The minimum temperature on the surface is observed in February or January. The greatest temperature gradient was recorded in the upper 2 cm layer. The gradient at the open fen was -2 °C/cm in February and 1.1 °C/cm in October. The peak of formation of the seasonally frozen layer occurs at the end of autumn or in the beginning of winter. The degradation of the seasonally frozen layer was observed both from top and bottom, but the degradation rate from the top is faster.

  6. Trees as methane sources: A case study of West Siberian South taiga

    NASA Astrophysics Data System (ADS)

    Churkina, A. I.; Mochenov, S. Yu; Sabrekov, S. F.; Glagolev, M. V.; Il’yasov, D. V.; Terentieva, I. E.; Maksyutov, S. S.

    2018-03-01

    Within this study, we were measuring methane emission from the tree trunks, leaves and branches in the seasonally flooded forest and in the forested bogs (pine-shrub-sphagnum ecosystems or “ryams”) in south taiga zone of Western Siberia. Our results suggest that the tree trunks may act as a methane conductor from the soil to the atmosphere bypassing the methanotrophically active zones of soil. The tree methane flux depends on a trunk diameter and an ecosystem type. The average methane emission from tree trunks was 0.0061±0.0003 mg CH4·m-2·h-1 per unit of ground area. The methane emission from branches and leaves was zero.

  7. Alvar soils and ecology in the boreal forest and taiga regions of Canada.

    NASA Astrophysics Data System (ADS)

    Ford, D.

    2012-04-01

    Alvars have been defined as "...a biological association based on a limestone plain with thin or no soil and, as a result, sparse vegetation. Trees and bushes are stunted or absent ... may include prairie spp." (Wikipedia). They were first described in southern Sweden, Estonia, the karst pavements of Yorkshire (UK) and the Burren (Eire). In North America alvars have been recognised and reported only in the Mixed Forest (deciduous/coniferous) Zone around the Great Lakes. An essential feature of the hydrologic controls on vegetation growth on natural alvars is that these terrains were glaciated in the last (Wisconsinan/Würm) ice age: the upper beds of any pre-existing epikarst were stripped away by glacier scour and there has been insufficient time for post-glacial epikarst to achieve the depths and densities required to support the deep rooting needed for mature forest cover. However, in the sites noted above, the alvars have been created, at least in part, by deforestation, overgrazing, burning to create browse, etc. and thus should not be considered wholly natural phenomena. There are extensive natural alvars in the Boreal Forest and Taiga ecozones in Canada. Their nature and variety will be illustrated with examples from cold temperate maritime climate settings in northern Newfoundland and the Gulf of St Lawrence and cold temperate continental to sub-arctic climates in northern Manitoba and the Northwest Territories.

  8. Smoke from Siberian Taiga Fires

    NASA Image and Video Library

    2003-10-08

    During the 2003 fire season, blazes in the taiga forests of Eastern Siberia were part of a vast network of fires across Siberia and the Russian Far East, northeast China and northern Mongolia seen here by NASA Terra spacecraft.

  9. Distribution of global fallouts cesium-137 in taiga and tundra catenae at the Ob River basin

    NASA Astrophysics Data System (ADS)

    Semenkov, I. N.; Usacheva, A. A.; Miroshnikov, A. Yu.

    2015-03-01

    The classification of soil catenae at the Ob River basin is developed and applied. This classification reflects the diverse geochemical conditions that led to the formation of certain soil bodies, their combinations and the migration fields of chemical elements. The soil and geochemical diversity of the Ob River basin catenae was analyzed. The vertical and lateral distribution of global fallouts cesium-137 was studied using the example of the four most common catenae types in Western Siberia tundra and taiga. In landscapes of dwarf birches and dark coniferous forests on gleysols, cryosols, podzols, and cryic-stagnosols, the highest 137Cs activity density and specific activity are characteristic of the upper soil layer of over 30% ash, while the moss-grass-shrub cover is characterized by low 137Cs activity density and specific activity. In landscapes of dwarf birches and pine woods on podzols, the maximum specific activity of cesium-137 is typical for moss-grass-shrub cover, while the maximum reserves are concentrated in the upper soil layer of over 30% ash. Bog landscapes and moss-grass-shrub cover are characterized by a minimum activity of 137Cs, and its reserves in soil generally decrease exponentially with depth. The cesium-137 penetration depth increases in oligotrophic histosols from northern to middle taiga landscapes from 10-15 to 40 cm. 137Cs is accumulated in oligotrophic histosols for increases in pH from 3.3 to 4.0 and in concretionary interlayers of pisoplinthic-cryic-histic-stagnosols. Cryogenic movement, on the one hand, leads to burying organic layers enriched in 137Cs and, on the other hand, to deducing specific activity when mixed with low-active material from lower soil layers.

  10. The TAIGA timing array HiSCORE - first results

    NASA Astrophysics Data System (ADS)

    Tluczykont, M.; Budnev, N.; Astapov, I.; Barbashina, N.; Bogdanov, A.; Boreyko, V.; Brückner, M.; Chiavassa, A.; Chvalaev, O.; Gress, O.; Gress, T.; Grishin, O.; Dyachok, A.; Epimakhov, S.; Fedorov, O.; Gafarov, A.; Gorbunov, N.; Grebenyuk, V.; Grinuk, A.; Horns, D.; Kalinin, A.; Karpov, N.; Kalmykov, N.; Kazarina, Y.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Konstantinov, A.; Korosteleva, E.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Kuzmichev, L.; Lemeshev, Yu.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Osipova, E.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Poleschuk, V.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Rubtsov, G.; Pushnin, A.; Samoliga, V.; Satunin, P.; Semeney, Yu.; Silaev, A.; Silaev, A.; Skurikhin, A.; Slunecka, M.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tkachev, L.; Voronin, D.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Zhurov, D.; Yashin, I.

    2017-03-01

    Observations of gamma rays up to several 100 TeV are particularly important to spectrally resolve the cutoff regime of the long-sought Pevatrons, the cosmic-ray PeV accelerators. One component of the TAIGA hybrid detector is the TAIGA-HiSCORE timing array, which currently consists of 28 wide angle (0.6 sr) air Cherenkov timing stations distributed on an area of 0.25 km2. The HiSCORE concept is based on (non-imaging) air shower front sampling with Cherenkov light. First results are presented.

  11. Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA): Status, results and perspectives

    NASA Astrophysics Data System (ADS)

    Kuzmichev, L.; Astapov, I.; Bezyazeekov, P.; Boreyko, V.; Borodin, A.; Brückner, M.; Budnev, N.; Chiavassa, A.; Gress, O.; Gress, T.; Grishin, O.; Dyachok, A.; Epimakhov, S.; Fedorov, O.; Gafarov, A.; Grebenyuk, V.; Grinyuk, A.; Haungs, A.; Horns, D.; Huege, T.; Ivanova, A.; Jurov, D.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kiryuhin, V.; Kokoulin, R.; Kompaniets, K.; Korosteleva, E.; Kostunin, D.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigal, R.; Osipova, E.; Pakharukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Poleschuk, V.; Popesku, M.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Pushnin, A.; Rubtsov, G.; Ryabov, E.; Sagan, Y.; Samoliga, V.; Schröder, F. G.; Semeney, Yu.; Silaev, A.; Silaev, A.; Sidorenko, A.; Skurikhin, A.; Slunecka, V.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Sulakov, V.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.

    2017-06-01

    We present the current status of high-energy cosmic-ray physics and gamma-ray astronomy at the Tunka Astrophysical Center (AC). This complex is located in the Tunka Valley, about 50 km from Lake Baikal. Present efforts are focused on the construction of the first stage of the gamma-ray observatory TAIGA - the TAIGA prototype. TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is designed for the study of gamma rays and charged cosmic rays in the energy range 1013 eV-1018 eV. The array includes a network of wide angle timing Cherenkov stations (TAIGA-HiSCORE), each with a FOV = 0.6 sr, plus up to 16 IACTs (FOV - 10∘× 10∘). This part covers an area of 5 km2. Additional muon detectors (TAIGA-Muon), with a total coverage of 2000 m2, are distributed over an area of 1 km2.

  12. Radiological investigations at the "Taiga" nuclear explosion site, part II: man-made γ-ray emitting radionuclides in the ground and the resultant kerma rate in air.

    PubMed

    Ramzaev, V; Repin, V; Medvedev, A; Khramtsov, E; Timofeeva, M; Yakovlev, V

    2012-07-01

    Samples of soil and epigeic lichens were collected from the "Taiga" peaceful nuclear explosion site (61.30°N 56.60°E, the Perm region, Russia) in 2009 and analyzed using high resolution γ-ray spectrometry. For soil samples obtained at six different plots, two products of fission ((137)Cs and (155)Eu), five products of neutron activation ((60)Co, (94)Nb, (152)Eu, (154)Eu, (207)Bi) and (241)Am have been identified and quantified. The maximal activity concentrations of (60)Co, (137)Cs, and (241)Am for the soils samples were measured as 1650, 7100, and 6800 Bq kg(-1) (d.w.), respectively. The deposit of (137)Cs for the top 20 cm of soil on the tested plots at the "Taiga" site ranged from 30 to 1020 kBq m(-2); the maximal value greatly (by almost 3 orders of magnitude) exceeded the regional background (from global fallout) level of 1.4 kBq m(-2). (137)Cs contributes approximately 57% of the total ground inventory of the man-made γ-ray emitters for the six plots tested at the "Taiga" site. The other major radionuclides -(241)Am and (60)Co, constitute around 40%. Such radionuclides as (60)Co, (137)Cs, (241)Am, and (207)Bi have also been determined for the epigeic lichens (genera Cladonia) that colonized certain areas at the ground lip produced by the "Taiga" explosion. Maximal activity concentrations (up to 80 Bq kg(-1) for (60)Co, 580 Bq kg(-1) for (137)Cs, 200 Bq kg(-1) for (241)Am, and 5 Bq kg(-1) for (207)Bi; all are given in terms of d.w.) have been detected for the lower dead section of the organisms. The air kerma rates associated with the anthropogenic sources of gamma radiation have been calculated using the data obtained from the laboratory analysis. For the six plots tested, the kerma rates ranged from 50 to 1200 nGy h(-1); on average, 51% of the dose can be attributed to (137)Cs and 45% to (60)Co. These estimates agree reasonably well with the results of the in situ measurements made during our field survey of the "Taiga" site in August

  13. Status of the Tunka Advanced Instrument for Cosmic Ray Physics and Gamma Astronomy (TAIGA)

    NASA Astrophysics Data System (ADS)

    Tkachev, L.; Astapov, I.; Bezyazeekov, P.; Borodin, A.; Brueckner, M.; Budnev, N.; Chiavassa, A.; Gress, O.; Gress, T.; Grishin, O.; Dyachok, A.; Fedorov, O.; Gafarov, A.; Grebenyuk, V.; Grinyuk, A.; Ivanova, A.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Korosteleva, E.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Kuzmichev, L.; Lemeshev, Yu.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoya, R.; Monkhoev, R.; Nachtigall, R.; Osipova, E.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Poleschuk, V.; Popesku, M.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Rjabov, E.; Rubtsov, G.; Pushnin, A.; Sabirov, B.; Sagan, Y.; Samoliga, V.; Semeney, Yu.; Silaev, A.; Silaev, A.; Sidorenkov, A.; Skurikhin, A.; Slunecka, V.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tluczykont, M.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.; Zhurov, D.

    The new TAIGA project is proposed to solve a number of fundamental problems of high- energy gamma astronomy, cosmic-ray and particle physics. The array will be located in the Tunka valley at the site of the Tunka-133 array. TAIGA will consist of wide-angle (FOV 0.6 sr) non-imaging Cherenkov optical detectors (TAIGA-HiSCORE) covering an area of up to 5 km2, and up to 16 IACTs (Imaging Atmospheric Cherenkov Telescopes) (FOV 10 × 10°) based on 9 m2 mirrors and muon detectors with a total sensitive area of 2000 m2. The current TAIGA status is presented.

  14. Evaluating the effects of fire and landscape characteristics on the export of carbon, nutrients and ions from watersheds of the Taiga Plains and Taiga Shield ecoregions of the NWT

    NASA Astrophysics Data System (ADS)

    Mengistu, S. G.; Tank, S. E.; Olefeldt, D.; Spence, C.; Quinton, W. L.; Dion, N.

    2016-12-01

    Fire is a natural process that can significantly modify landscapes and ecosystems. In permafrost-affected terrains, fire-induced changes to soils and active layer depths can have important implications for hydrological flow paths and the chemistry of runoff water, and therefore also the health and functioning of recipient aquatic ecosystems. Although the effects of fire on water chemistry have been relatively well studied in non-permafrost affected landscapes, less attention has been given to how fire affects northern aquatic ecosystems, particularly those of the Northwest Territories (NWT), despite an increasing frequency of fire in this region. To address this gap, we make use of a recent large-scale burn that occurred across the discontinuous permafrost landscape of the southern NWT, to explore how fire and variations in landscape characteristics affect water chemistry in this area. The study collected water chemistry samples during the summers of 2015 and 2016 from paired watersheds in the Taiga Shield (Boundary Creek / Baker Creek) and Taiga Plains (Spence Creek / Scotty Creek) ecoregions, in addition to a synoptic survey that measured discharge and water chemistry across a series of 50 watersheds in these two regions. We specifically targeted the Taiga Shield and Plains since differences in soil characteristics between these two regions were expected to lead to differences in how recipient aquatic systems respond to fire. Preliminary results from the paired catchment work show a clear spike in the chemistry of fire-affected watersheds early in the ice-free season, followed by a period when stream water chemistry in burned watersheds declines to a level that is similar to that in the unburned analogs. While average electrical conductivity, Ca, Na, and Hg concentrations were highest in the Plains watersheds, constituents including average TN, TP, Al, DOC, Fe, K, Mg, and Cl appeared to be the highest for the fire-affected Shield watershed. Preliminary results

  15. Distinct temperature sensitivity among taiga and tundra shrubs in Alaska

    NASA Astrophysics Data System (ADS)

    Andreu-Hayles, L.; Anchukaitis, K. J.; D'Arrigo, R.

    2014-12-01

    Shrub expansion into Arctic and alpine tundra ecosystems is well documented, mostly over the last 50 years, based on remote sensing data, aerial photography, and in-situ observations. Warming temperatures are considered the main driver of the observed change in shrub vegetation patterns. Here, we assess the relationship between temperatures and shrub growth from five populations of Salix spp. (willow) and Alnus spp. (alder) in Alaska growing within the tundra and the boreal forest (~taiga) using dendrochronological techniques. The three tundra shrub sites are located on the Dalton Highway north from Toolik Lake (~69ºN 148ºW), whereas the two taiga shrub sites are located closer to Fairbanks at the Twelve Mile Summit site (~65ºN 146ºW). Because shrub ages vary among the studied populations lead to different time spans for the ring-width chronologies generated, a common period with available satellite data spanning from 1982 to 2010 was selected for this study. All tundra shrub chronologies shared a strong positive response to summer temperatures despite growing in heterogeneous site conditions and belonging to different species. In contrast, in the taiga, summer temperatures enhance willow growth, whereas alder growth appears almost insensitive to temperature over the interval studied. Extending the analyses back in time, a very strong positive relationship was found between alder ring-width and June temperatures prior to 1970. This phenomenon, a weakening of the previously existing relationship between growth and temperatures, was also detected in white spruce (Picea glauca) growing at the same site, and it is known in the literature as the 'divergence problem'. Thus, at this taiga location, alder shrubs and trees seem to have similar growth patterns. Summer temperatures no longer seem to enhance taiga alder growth. Shrubs of different species exposed to the same climatic conditions can exhibit varied growth responses. The distinct temperature sensitivities

  16. Comparing carbon storage of Siberian tundra and taiga permafrost ecosystems at very high spatial resolution

    NASA Astrophysics Data System (ADS)

    Siewert, Matthias B.; Hanisch, Jessica; Weiss, Niels; Kuhry, Peter; Maximov, Trofim C.; Hugelius, Gustaf

    2015-10-01

    Permafrost-affected ecosystems are important components in the global carbon (C) cycle that, despite being vulnerable to disturbances under climate change, remain poorly understood. This study investigates ecosystem carbon storage in two contrasting continuous permafrost areas of NE and East Siberia. Detailed partitioning of soil organic carbon (SOC) and phytomass carbon (PC) is analyzed for one tundra (Kytalyk) and one taiga (Spasskaya Pad/Neleger) study area. In total, 57 individual field sites (24 and 33 in the respective areas) have been sampled for PC and SOC, including the upper permafrost. Landscape partitioning of ecosystem C storage was derived from thematic upscaling of field observations using a land cover classification from very high resolution (2 × 2 m) satellite imagery. Nonmetric multidimensional scaling was used to explore patterns in C distribution. In both environments the ecosystem C is mostly stored in the soil (≥86%). At the landscape scale C stocks are primarily controlled by the presence of thermokarst depressions (alases). In the tundra landscape, site-scale variability of C is controlled by periglacial geomorphological features, while in the taiga, local differences in catenary position, soil texture, and forest successions are more important. Very high resolution remote sensing is highly beneficial to the quantification of C storage. Detailed knowledge of ecosystem C storage and ground ice distribution is needed to predict permafrost landscape vulnerability to projected climatic changes. We argue that vegetation dynamics are unlikely to offset mineralization of thawed permafrost C and that landscape-scale reworking of SOC represents the largest potential changes to C cycling.

  17. Dynamics of Soil Properties and Plant Composition during Postagrogenic Evolution in Different Bioclimatic Zones

    NASA Astrophysics Data System (ADS)

    Telesnina, V. M.; Kurganova, I. N.; Lopes de Gerenyu, V. O.; Ovsepyan, L. A.; Lichko, V. I.; Ermolaev, A. M.; Mirin, D. M.

    2017-12-01

    The postagrogenic dynamics of acidity and some parameters of humus status have been studied in relation to the restoration of zonal vegetation in southern taiga (podzolic and soddy-podzolic soils ( Retisols)), coniferous-broadleaved (subtaiga) forest (gray forest soil ( Luvic Phaeozem)), and forest-steppe (gray forest soil ( Haplic Phaeozem)) subzones. The most significant transformation of the studied properties of soils under changing vegetation has been revealed for poor sandy soils of southern taiga. The degree of changes in the content and stocks of organic carbon, the enrichment of humus in nitrogen, and acidity in the 0- to 20-cm soil layer during the postagrogenic evolution decreases from north to south. The adequate reflection of soil physicochemical properties in changes of plant cover is determined by the climatic zone and the land use pattern. A correlation between the changes in the soil acidity and the portion of acidophilic species in the plant cover is revealed for the southern taiga subzone. A positive relationship is found between the content of organic carbon and the share of species preferring humus-rich soils in the forest-steppe zone.

  18. Reactive nitrogen oxides and ozone above a taiga woodland

    NASA Technical Reports Server (NTRS)

    Bakwin, Peter S.; Jacob, Daniel J.; Wofsy, Steven C.; Munger, J. William; Daube, Bruce C.; Bradshaw, John D.; Sandholm, Scott T.; Talbot, Robert W.; Singh, Hanwant B.; Gregory, Gerald L.

    1994-01-01

    Measurements of reactive nitrogen oxides (NO(x) and NO(y)) and ozone (O3) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Artic Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O3 were strongly modulated by the synoptic scale meteorology that brought air from various source regions to the site. Industrial pollution from the Great Lakes region of the U.S. and Canada appears to be a major source for periodic elevation of NO(x), and NO(y) and O3. We find that NO/NO2 ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NO(x) and O3, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO2, at the taiga site. Ratios of NO(x) to NO(y) were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3A. This is probably the result of high PAN levels and suppressed formation of HNO3 from NO2 due to high levels of biogenic hydrocarbons at the ABLE 3B site.

  19. Reactive nitrogen oxides and ozone above a taiga woodland

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bakwin, P.S.; Jacob, D.J.; Wofsy, S.C.

    1994-01-20

    Measurements of reactive nitrogen oxides (NO{sub x} and NO{sub y}) and ozone (O{sub 3}) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Arctic Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O{sub 3} were strongly modulated by the synoptic scale meteorology that brought air from various regions to the site. Industrial pollution from the Great Lakes region of the US and Canada appears to be a major source for periodic elevation of NO{sub x}, NO{sub y} and O{sub 3}. We find that NO/NO{submore » 2} ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NO{sub x} and O{sub 3}, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO{sub 2}, at the taiga site. Ratios of NO{sub x} to NO{sub y} were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3A. This is probably the result of high PAN levels and suppressed formation of HNO{sub 3} from NO{sub 2} due to high levels of biogenic hydrocarbons at the ABLE 3B site. 36 refs., 7 figs., 3 tabs.« less

  20. [Southern taiga combined natural foci of spirochetoses].

    PubMed

    Korenberg, E I; Anan'ina, Iu V; Gorelova, N B; Savel'eva, O V; Kovalevskiĭ, Iu V; Petrov, E M

    2011-01-01

    Study of possibility of existence of combined natural foci of spirochetoses (ixodes tick borrelioses and leptospiroses) in typical taiga forests, and their etiologic and reservoir-host structure. Small mammals of 19 species were captured in 1992-2010 at a station in low-mountain southern taiga forests of Chusov area of Perm region. Borreliae were isolated by seeding urinary bladder or aural bioptates into BSK II medium, leptospirae--by seeding a suspension of kidney tissue into Vervoort-Wolf medium. 1350 animals were studied by seeding for borrelia infection and 1077--for leptospira. 287 of those, small animals of 6 species, were simultaneously studied for borrelia and leptospira infection. Borrelia isolates were identified by using PCR and restriction fragment length polymorphism methods, and leptospirae--by using standard diagnostic agglutinating sera kit. Blood of 2893 rodents of 12 species and insectivorous of 7 species was studied in microagglutination reaction for the detection of antibodies against leptospirae. Infection by Borrelia garinii and Borrelia afzelii or Grippotyphosa serogroup leptospira was detected in 6 most numerous species of forest small mammals. 3 root voles and I bankvole were simultaneously infected by borreliae and leptospirae. B. garinii and Grippotyphosa serogroup leptospira were simultaneously isolated from 2 root voles, and B. garinii and Javanica serogroup Leptospira interrogans--from 1 root vole. A bank vole was infected by B. afzelii and Javanica serogroup leptospira. Mixed-infected animals composed 1.4% of all animals of background species studied in parallel. The data obtained indicate a presence of natural foci of leptospiroses in the southern taiga forest pre-Urals. The data confirm the conceptions regarding a predominant presence in European forest ecosystems of foci with Grippotyphosa serogroup L. interrogans pathogen, and the main carrier ofthese leptospirae being bank vole. Combined natural foci of spirochetoses of two

  1. Assessing the Tundra-taiga Boundary with Multi-Sensor Satellite Data

    NASA Technical Reports Server (NTRS)

    Ranson, K. J.; Sun, G.; Kharuk, V. I.; Kovacs, K.

    2004-01-01

    Monitoring the dynamics of the circumpolar boreal forest (taiga) and Arctic tundra boundary is important for understanding the causes and consequences of changes observed in these areas. This ecotone, the world's largest, stretches for over 13,400 km and marks the transition between the northern limits of forests and the southern margin of the tundra. Because of the inaccessibility and large extent of this zone, remote sensing data can play an important role for mapping the characteristics and monitoring the dynamics. Basic understanding of the capabilities of existing space borne instruments for these purposes is required. In this study we examined the use of several remote sensing techniques for identifying the existing tundra- taiga ecotone. These include Landsat-7, MISR, MODIS and RADARSAT data. Historical cover maps, recent forest stand measurements and high-resolution IKONOS images were used for local ground truth. It was found that a tundra-taiga transitional area can be characterized using multi- spectral Landsat ETM+ summer images, multi-angle MISR red band reflectance images, RADARSAT images with larger incidence angle, or multi-temporal and multi-spectral MODIS data. Because of different resolutions and spectral regions covered, the transition zone maps derived from different data types were not identical, but the general patterns were consistent.

  2. Radiological investigations at the "Taiga" nuclear explosion site: Site description and in situ measurements.

    PubMed

    Ramzaev, V; Repin, V; Medvedev, A; Khramtsov, E; Timofeeva, M; Yakovlev, V

    2011-07-01

    In the summer of 2009, we performed a field survey of the "Taiga" peaceful underground nuclear explosion site, the Perm region, Russia (61.30° N, 56.60° E). The explosion was carried out by the USSR in 1971. This paper provides an extended summary of the available published data on the "Taiga" experiment. A detailed description of the site is illustrated by original aerial and ground-level photos. A large artificial lake (700 m long and 350 m wide) currently occupies the central area of the experimental site. The ground lip surrounding the lake is covered by a newly grown mixed forest. In situ measurements, performed in August 2009, revealed elevated levels of the γ-ray dose rate in air on the banks of the lake "Taiga". Two hot spots were detected on the eastern bank of the lake. The excess of the γ-ray radiation is attributable to the man-made radionuclides (60)Co and (137)Cs. The current external γ-ray dose rate to a human from the contaminations associated with the "Taiga" experiment was between 9 and 70 μSv per week. Periodic monitoring the site is recommended. 2011 Elsevier Ltd. All rights reserved.

  3. Decadal Variations in Eastern Canada's Taiga Wood Biomass Production Forced by Ocean-Atmosphere Interactions.

    PubMed

    Boucher, Etienne; Nicault, Antoine; Arseneault, Dominique; Bégin, Yves; Karami, Mehdi Pasha

    2017-05-26

    Across Eastern Canada (EC), taiga forests represent an important carbon reservoir, but the extent to which climate variability affects this ecosystem over decades remains uncertain. Here, we analyze an extensive network of black spruce (Picea mariana Mill.) ring width and wood density measurements and provide new evidence that wood biomass production is influenced by large-scale, internal ocean-atmosphere processes. We show that while black spruce wood biomass production is primarily governed by growing season temperatures, the Atlantic ocean conveys heat from the subtropics and influences the decadal persistence in taiga forests productivity. Indeed, we argue that 20-30 years periodicities in Sea Surface Temperatures (SSTs) as part of the the Atlantic Multi-decadal Oscillation (AMO) directly influence heat transfers to adjacent lands. Winter atmospheric conditions associated with the North Atlantic Oscillation (NAO) might also impact EC's taiga forests, albeit indirectly, through its effect on SSTs and sea ice conditions in surrounding seas. Our work emphasizes that taiga forests would benefit from the combined effects of a warmer atmosphere and stronger ocean-to-land heat transfers, whereas a weakening of these transfers could cancel out, for decades or longer, the positive effects of climate change on Eastern Canada's largest ecosystem.

  4. Research opportunities and needs in the taiga of Alaska.

    Treesearch

    Austin E. Helmers; Charles T. Cushwa

    1973-01-01

    An appraisal of taiga (the northern forests of interior Alaska) environment research opportunities and needs was made based upon accomplishments since Alaskan statehood, current involvement of citizens in resource issues, information needs incident to the National Environmental Policy Act of 1969, and needs of new resource managing agencies and changing ownerships...

  5. Hot spots, indicator taxa, complementarity and optimal networks of taiga.

    PubMed Central

    Virolainen, K M; Ahlroth, P; Hyvärinen, E; Korkeamäki, E; Mattila, J; Päiivinen, J; Rintala, T; Suomi, T; Suhonen, J

    2000-01-01

    If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important group indicating the conservation value of old growth taiga forests. Random selection provided a better option. Thus, certain groups may function as good indicators for maximizing the overall species richness of some taxonomic groups, but all taxa should be examined separately. PMID:10885520

  6. Diagnostics of hydromorphism in soils of autonomous positions on the Severo-Sos'vinsk Upland (Western Siberia)

    NASA Astrophysics Data System (ADS)

    Avetov, N. A.; Sopova, E. O.; Golovleva, Yu. A.; Kiryushin, A. V.; Krasilnikov, P. V.

    2014-11-01

    The complex studies of hydromorphism features in taiga weakly differentiated soils using morphological (color), chemical (iron content in different extracts, indicators of reducing conditions (IRIS)), and geobotanic (using the Ramenskii scale) methods have led to ambiguous conclusions. In all the soils, surface gleying was manifested. According to the results obtained by different methods, the maximum reduction processes were related to either the sublitter or the next deeper horizon. The Schwertmann coefficient, the criterion of Bodegom, and the Ramenskii scale indicated an increase of hydromorphism in the soils studied in the following sequence: the lower part of the ridge slopes drained by the small gullies < the middle part of the slopes < the flat tops of the ridges < the depression between the ridges. The morphological diagnostics of gleying proved to be a less sensitive method, which can recognize only the most contrasting hydromorphic soils. The lower horizons in some taiga soils have a bluish gray color probably not related to the recent soil hydromorphism.

  7. The wide-aperture gamma-ray telescope TAIGA-HiSCORE in the Tunka Valley: Design, composition and commissioning

    NASA Astrophysics Data System (ADS)

    Gress, O.; Astapov, I.; Budnev, N.; Bezyazeekov, P.; Bogdanov, A.; Boreyko, V.; Brückner, M.; Chiavassa, A.; Chvalaev, O.; Dyachok, A.; Gress, T.; Epimakhov, S.; Fedoseev, E.; Gafarov, A.; Gorbunov, N.; Grebenyuk, V.; Grinuk, A.; Grishin, O.; Horns, D.; Ivanova, A.; Kalinin, A.; Karpov, N.; Kalmykov, N.; Kazarina, Yu.; Kirichkov, N.; Kiryuhin, S.; Kokoulin, R.; Komponiest, K.; Korosteleva, E.; Kozhin, V.; Kunnas, M.; Kuzmichev, L.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Platonov, V.; Poleschuk, V.; Popova, E.; Porelli, A.; Prosin, V.; Rubtsov, G.; Pushnin, A.; Samoliga, V.; Saunkin, A.; Semeney, Yu.; Shaibonov(ju), B.; Silaev, A.; Silaev(ju), A.; Skurikhin, A.; Slucka, V.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tarashchansky, B.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Voronin, D.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.

    2017-02-01

    The new TAIGA-HiSCORE non-imaging Cherenkov array aims to detect air showers induced by gamma rays above 30 TeV and to study cosmic rays above 100 TeV. TAIGA-HiSCORE is made of integrating air Cherenkov detector stations with a wide field of view (0.6 sr), placed at a distance of about 100 m. They cover an area of initially ∼0.25 km2 (prototype array), and of ∼5 km2 at the final phase of the experiment. Each station includes 4 PMTs with 20 or 25 cm diameter, equipped with light guides shaped as Winstone cones. We describe the design, specifications of the read-out, DAQ and control and monitoring systems of the array. The present 28 detector stations of the TAIGA-HiSCORE engineering setup are in operation since September 2015.

  8. Low-Concentration Kinetics of Atmospheric CH4 Oxidation in Soil and Mechanism of NH4+ Inhibition

    PubMed Central

    Gulledge, Jay; Schimel, Joshua P.

    1998-01-01

    NH4+ inhibition kinetics for CH4 oxidation were examined at near-atmospheric CH4 concentrations in three upland forest soils. Whether NH4+-independent salt effects could be neutralized by adding nonammoniacal salts to control samples in lieu of deionized water was also investigated. Because the levels of exchangeable endogenous NH4+ were very low in the three soils, desorption of endogenous NH4+ was not a significant factor in this study. The Km(app) values for water-treated controls were 9.8, 22, and 57 nM for temperate pine, temperate hardwood, and birch taiga soils, respectively. At CH4 concentrations of ≤15 μl liter−1, oxidation followed first-order kinetics in the fine-textured taiga soil, whereas the coarse-textured temperate soils exhibited Michaelis-Menten kinetics. Compared to water controls, the Km(app) values in the temperate soils increased in the presence of NH4+ salts, whereas the Vmax(app) values decreased substantially, indicating that there was a mixture of competitive and noncompetitive inhibition mechanisms for whole NH4+ salts. Compared to the corresponding K+ salt controls, the Km(app) values for NH4+ salts increased substantially, whereas the Vmax(app) values remained virtually unchanged, indicating that NH4+ acted by competitive inhibition. Nonammoniacal salts caused inhibition to increase with increasing CH4 concentrations in all three soils. In the birch taiga soil, this trend occurred with both NH4+ and K+ salts, and the slope of the increase was not affected by the addition of NH4+. Hence, the increase in inhibition resulted from an NH4+-independent mechanism. These results show that NH4+ inhibition of atmospheric CH4 oxidation resulted from enzymatic substrate competition and that additional inhibition that was not competitive resulted from a general salt effect that was independent of NH4+. PMID:9797279

  9. TAIGA: Twente Advanced Interactive Graphic Authoring System. A New Concept in Computer Assisted Learning (CAL) and Educational Research. Doc 88-18.

    ERIC Educational Resources Information Center

    Pilot, A.

    TAIGA (Twente Advanced Interactive Graphic Authoring system) is a system which can be used to develop instructional software. It is written in MS-PASCAL, and runs on computers that support MS-DOS. Designed to support the production of structured software, TAIGA has a hierarchical structure of three layers, each with a specific function, and each…

  10. [Life cycle of the taiga tick ixodes persulcatus in taiga forests of the eastern Sayan Plateau].

    PubMed

    Korotkov, Iu S

    2014-01-01

    The Ixodes persulcatus life cycle has been studied in natural environments of taiga fo- rests in The Eastern Sayan Plateau (56 10' N, 91 30' E). Engorged larvae and nymphs de- velop with a morphogenetic diapause or without diapause, with ratio of these two ways of development for larvae and nymphs 77.25/22.75% and 43.43/56.57%, respectively. The hypothetic season hemipopulation consists of 34.5 +/- 4.5, 50.1 +/- 1.3, 13.2 +/- 4.0 n 2.2% of unfed imagoes, completing 3-year, 4-year, 5-year, and 6-year life cycles, respectively. Mean life span is 3.83 +/- 0.10 years per generation. The "life table" predicting the probability to complete life cycle through phases from egg to adult, was developed.

  11. Underestimation of the Tambora effects in North American taiga ecosystems

    NASA Astrophysics Data System (ADS)

    Gennaretti, Fabio; Boucher, Etienne; Nicault, Antoine; Gea-Izquierdo, Guillermo; Arseneault, Dominique; Berninger, Frank; Savard, Martine M.; Bégin, Christian; Guiot, Joel

    2018-03-01

    The Tambora eruption (1815 AD) was one of the major eruptions of the last two millennia and has no equivalents over the last two centuries. Here, we collected an extensive network of early meteorological time series, climate simulation data and numerous, well-replicated proxy records from Eastern Canada to analyze the strength and the persistence of the Tambora impact on the regional climate and forest processes. Our results show that the Tambora impacts on the terrestrial biosphere were stronger than previously thought, and not only affected tree growth and carbon uptake for a longer period than registered in the regional climate, but also determined forest demography and structure. Increased tree mortality, four times higher than the background level, indicates that the Tambora climatic impact propagated to influence the structure of the North American taiga for several decades. We also show that the Tambora signal is more persistent in observed data (temperature, river ice dynamics, forest growth, tree mortality) than in simulated ones (climate and forest-growth simulations), indicating that our understanding of the mechanisms amplifying volcanic perturbations on climates and ecosystems is still limited, notably in the North American taiga.

  12. Soil respiration dynamics in the middle taiga of Central Siberia region

    NASA Astrophysics Data System (ADS)

    Makhnykina, Anastasia; Prokushkin, Anatoly; Polosukhina, Daria

    2017-04-01

    A large amount of carbon in soil is released to the atmosphere through soil respiration, which is the main pathway of transferring carbon from terrestrial ecosystems (Comstedt et al., 2011). Considering that boreal forests is a large terrestrial sink (Tans et al., 1990) and represent approximately 11 % of the Earth's total land area (Gower et al., 2001), even a small change in soil respiration could significantly intensify - or mitigate - current atmospheric increases of CO2, with potential feedbacks to climate change. The objectives of the present study are: (a) to study the dynamic of CO2 emission from the soil surface during summer season (from May to October); (b) to identify the reaction of soil respiration to different amount of precipitation as the main limiting factor in the region. The research was located in the pine forests in Central Siberia (60°N, 90°E), Russia. Sample plots were represented by the lichen pine forest, moss pine forest, mixed forest and anthropogenic destroyed area. We used the automated soil CO2 flux system based on the infrared gas analyzer -LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths -5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. The presence and type of ground cover substantially affects the value of soil respiration fluxes. The carbon dioxide emission from the soil surface averaged 5.4 ±2.3 μmol CO2 m-2 s-1. The destroyed area without plant cover demonstrated the lowest soil respiration (0.1-5.6 μmol CO2 m-2 s-1). The lowest soil respiration among forested areas was observed in the feathermoss pine forest. The lichen pine forest was characterized by the intermediate values of soil respiration. The maximum soil respiration values and seasonal fluctuations were obtained in the mixed forest (2.3-29.3 μmol CO2 m-2 s-1). The analysis of relation between soil CO2 efflux and climatic conditions identified the parameters with

  13. [Abundance of larvae and nymphs of the taiga tick Ixodes persuicatus (Acari: Ixodidae) on small mammals in the cut-over lands of the middle taiga subzone of Karelia].

    PubMed

    Bugmyrin, S V; Bespiatova, L A; Anikanova, V S; Ieshko, E P

    2009-01-01

    Data of long-term investigations (1998-2004) on the abundance of the taiga tick larvae and nymphs in the cut-over lands of different age in the middle taiga subzone of Karelia (62 degrees 04'S; 33 degrees 55'W) are presented. The investigation was carried out on three model cut-over lands of different age: 1) "young" cut-over land; age of cut-over in the beginning of investigation is 7 years; Betula-Deschampsia cespitosa-Agrostis tenuis; 2) "middle" cut-over land; age of cut-over is 12 years; Salix-Deschampsia cespitosa-Agrostis tenuis; 3) "old" cut-over land; age of cut-over 25 years; Alnus incana-Rubus idaeus-grass. The number of ticks was estimated by using common parasitological indices: prevalence, abundance, and index of feeding intensity (the tick abundance multiply by the number of small mammals per hundred traps-nights). In the beginning of investigation the "young" cut-over land was a typical meadow association. The lowest tick abundance was recorded here. That was a result of unfavorable abiotic conditions and low number of small mammals in the beginning of summer. "Middle" cut-over land is characterized by the highest number of the tick larvae, which is the evidence for high number of the hosts of tick imago. "Old" cut-over land has the optimum conditions for development of taiga ticks. High abundance of the ticks (larvae and nymphs) was recorded during the whole period of investigations. The number of preimaginal ticks is shown to be much higher in cut-over lands as compared with that in mixed and coniferous forests, due to the higher number of small mammals.

  14. The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

    PubMed

    Wang, Xin; Cao, Lei; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

    2018-01-01

    The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle.

  15. The Far East taiga forest: unrecognized inhospitable terrain for migrating Arctic-nesting waterbirds?

    PubMed Central

    Wang, Xin; Bysykatova, Inga; Xu, Zhenggang; Rozenfeld, Sonia; Jeong, Wooseog; Vangeluwe, Didier; Zhao, Yunlin; Xie, Tianhe; Yi, Kunpeng; Fox, Anthony David

    2018-01-01

    The degree of inhospitable terrain encountered by migrating birds can dramatically affect migration strategies and their evolution as well as influence the way we develop our contemporary flyway conservation responses to protect them. We used telemetry data from 44 tagged individuals of four large-bodied, Arctic breeding waterbird species (two geese, a swan and one crane species) to show for the first time that these birds fly non-stop over the Far East taiga forest, despite their differing ecologies and migration routes. This implies a lack of suitable taiga refuelling habitats for these long-distance migrants. These results underline the extreme importance of northeast China spring staging habitats and of Arctic areas prior to departure in autumn to enable birds to clear this inhospitable biome, confirming the need for adequate site safeguard to protect these populations throughout their annual cycle. PMID:29479493

  16. Low-concentration kinetics of atmospheric CH{sub 4} oxidation in soil and mechanism of NH{sub 4}{sup +} inhibition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gulledge, J.; Schimel, J.P.

    1998-11-01

    NH{sub 4}{sup +} inhibition kinetics for CH{sub 4} oxidation were examined at near-atmospheric CH{sub 4} concentrations in three upland forest soils. Whether NH{sub 4}{sup +}-independent salt effects could be neutralized by adding nonammoniacal salts to control samples in lieu of deionized water was also investigated. Because the levels of exchangeable endogenous NH{sub 4}{sup +} were very low in the three soils, desorption of endogenous NH{sub 4}{sup +} was not a significant factor in this study. The K{sub m(app)} values for water-treated controls were 9.8, 22, and 57 nM for temperate pine, temperate hardwood, and birch taiga soils, respectively. At CH{submore » 4} concentrations of {le}15 {micro}l liter{sup {minus}1}, oxidation followed first-order kinetics in the fine-textured taiga soil, whereas the coarse-textured temperate soils exhibited Michaelis-Menten kinetics. Compared to water controls, the K{sub m(app)} values in the temperate soils increased in the presence of NH{sub 4}{sup +} salts, whereas the V{sub max(app)} values decreased substantially, indicating that there was a mixture of competitive and noncompetitive inhibition mechanisms for whole NH{sub 4}{sup +} salts. Compared to the corresponding K{sup +} salt controls, the K{sub m(app)} values for NH{sub 4}{sup +} salts increased substantially, whereas the V{sub max(app)} values remained virtually unchanged, indicating that NH{sub 4}{sup +} acted by competitive inhibition. Nonammoniacal salts caused inhibition to increase with increasing CH{sub 4} concentrations in all three soils. In the birch taiga soil, this trend occurred with both NH{sub 4}{sup +} and K{sup +} salts, and the slope of the increase was not affected by the addition of NH{sub 4}{sup +}. Hence, the increase in inhibition resulted from an NH{sub 4}{sup +}-independent mechanism.« less

  17. The influence of fires on the properties of forest soils in the Amur River basin (the Norskii Reserve)

    NASA Astrophysics Data System (ADS)

    Tsibart, A. S.; Gennadiev, A. N.

    2008-07-01

    The influence of forest fires on the properties of taiga brown, gley taiga brown, and alluvial bog soils widespread in the area of the Norskii Reserve (the Amur River basin) was studied. During several years after the fire, the humus content increased, especially in the soils subjected to fires of high intensity. In the soils of steep slopes, the humus content decreased due to damage to the forest vegetation and activation of lateral runoff after the fire. As a rule, in the soils subjected to fire, the C ha-to-C fa ratio increased and correlated with the fire intensity. Some relationships between the forest fires and the acid-base properties of the soils were revealed. After the fires, the pH values often became higher. The stronger the fire, the higher the pH values. The stony soils differed from the other ones, since the reaction of their upper horizons turned out to be more acid after the fires. The analysis of the authors’ and literature data showed that the pyrogenic changes of some soil properties have been poorly studied and need further investigation, including their geographical aspects.

  18. Transformation of peat horizon in swampy southern taiga forests under the impact of surface drainage

    NASA Astrophysics Data System (ADS)

    Vomperskii, S. E.; Vomperskaya, M. I.; Glukhova, T. V.; Valyaeva, N. A.

    2017-10-01

    The results of stationary studies of swampy southern taiga forests in Yaroslavl oblast are presented. Estimates of changes in the thickness of peat horizon in peat podzolic gley soils (Folic Albeluvisols) of forests subjected to clearcutting and further intensive forest management in the past 30 years are given. The mean annual precipitation in these three decades has been 116 mm higher than that during the preceding three decades, which has led to a progressive swamping of spruce stands on heavy loamy soils within virtually flat (with slopes up to 0.0035) surfaces and an increase in the organic matter storage in the peat soil horizon with the mean annual rate of 22-68 g/m2. On more pronounced slopes (0.0050), no swamping of spruce and pine stands growing on sandy soils has taken place. Surface drainage of swampy forests through the network of shallow ditches has led to an increase in the productivity of forests; in most cases, the pool of organic matter in the peat horizon has been decreasing with the mean annual rate of 32-46 g/m2. This attests to the reversible character of swamping in dependence on climatic fluctuations and forestry measures. Changes in the carbon pool of swampy soils during short (several years) excessively wet or excessively dry periods may be significantly higher than the average values for 30 years in different types of forests. This allows us to consider swampy forests as the source of significant errors in the estimates of the current contribution of biota to the carbon cycle, because their role (as well as the role of other forests) is assessed without taking into account considerable short-term fluctuations in the carbon pool of their soils.

  19. High resolution wetland mapping in West Siberian taiga zone for methane emission inventory

    NASA Astrophysics Data System (ADS)

    Terentieva, I. E.; Glagolev, M. V.; Lapshina, E. D.; Sabrekov, A. F.; Maksyutov, S. S.

    2015-12-01

    High latitude wetlands are important for understanding climate change risks because these environments sink carbon and emit methane. Fine scale heterogeneity of wetland landscapes pose challenges for producing the greenhouse gas flux inventories based on point observations. To reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the taiga zone of West Siberia on a scene-by-scene basis using a supervised classification of Landsat imagery. The training dataset was based on high-resolution images and field data that were collected at 28 test areas. Classification scheme was aimed at methane inventory applications and included 7 wetland ecosystem types composing 9 wetland complexes in different proportions. Accuracy assessment based on 1082 validation polygons of 10 × 10 pixels indicated an overall map accuracy of 79 %. The total area of the wetlands and water bodies was estimated to be 52.4 Mha or 4-12 % of the global wetland area. Ridge-hollow complexes prevail in WS's taiga, occupying 33 % of the domain, followed by forested bogs or "ryams" (23 %), ridge-hollow-lake complexes (16 %), open fens (8 %), palsa complexes (7 %), open bogs (5 %), patterned fens (4 %), and swamps (4 %). Various oligotrophic environments are dominant among the wetland ecosystems, while fens cover only 14 % of the area. Because of the significant update in the wetland ecosystem coverage, a considerable revaluation of the total CH4 emissions from the entire region is expected. A new Landsat-based map of WS's taiga wetlands provides a benchmark for validation of coarse-resolution global land cover products and wetland datasets in high latitudes.

  20. A latitudinal gradient in tree growth response to climate warming in the Siberian taiga

    Treesearch

    Andrea H. Lloyd; Andrew G. Bunn; Logan Berner

    2010-01-01

    We investigated the climate response of three Siberian taiga species, Larix cajanderi, Picea obovata, and Pinus sylvestris, across a latitudinal gradient in central Siberia. We hypothesized that warming is more frequently associated with increased growth for evergreen conifers (P. obovata and P....

  1. [Testate amoebae inhabiting middle taiga bogs in Western Siberia].

    PubMed

    Kur'ina, I V; Preĭs, Iu I; Bobrov, A A

    2010-01-01

    The population of testate amoebae from the most typical middle taiga bogs of Western Siberia have been studied. More than one hundred (103) species and intraspecific taxons of testate amoebae have been revealed in recent surface samples. The relation between ecological characteristics of habitats and the composition of a Protozoa population has been demonstrated. The ecological preferences of species concerning the index of wetness, ash level, and acidity have been revealed. Using the correspondence analysis, the ecological optimums and the tolerance of species and intraspecific taxons of testate amoebae have been established.

  2. [Exoskeleton anomalies among taiga tick males from populations of the Asiatic part of Russia].

    PubMed

    Nikitin, A Ya; Morozov, I M

    2017-01-01

    The taiga tick (Icodes persulcatus, Schulze, 1930) is the main and most epidemiologically dangerous vector of tick-born encephalitis virus (TBEV) and Borrelia in most parts of Russia's territory (Alekseev et al., 2008). The purpose of this article is to describe the incidence rate of I. persulcatus males with exoskeleton anomalies in populations of the Asiatic part of Russia. A total of 2630 taiga tick males were morphologically analyzed. They were collected in Far Eastern, Siberian and Ural Federal Districts (respectively, FEFD, SFD, UFD) in 15 geographically remote locations. It is shown that in all populations there are adult ticks with impaired exoskeleton, among which two types dominate: twin dents at the back of conscutum (P11), and uneven surface of conscutum - a "shagreen skin" (P9). The frequency of abnormalities in males from the areas with temperate monsoon and temperate continental climate (FEFD) was definitely lower (6.5 ± 1.05 %), than in individuals from the territories of SFD (29.7 ± 1.03 %) and UFD (25.8 ± 3.93 %) with continental and sharply continental climate. FEFD territory is also characterized by a less number of males having two simultaneous exoskeleton anomalies. Similar district-preconditioned differences in the frequency of recorded body distortions are also typical of females, with a higher percentage of deviant individuals in comparison with males. Thus, the identified polymorphism of exoskeleton structure of the taiga tick may reflect the natural phenogeographical variability of this trait and might not be the result of human impact.

  3. A Subpixel Classification of Multispectral Satellite Imagery for Interpetation of Tundra-Taiga Ecotone Vegetation (Case Study on Tuliok River Valley, Khibiny, Russia)

    NASA Astrophysics Data System (ADS)

    Mikheeva, A. I.; Tutubalina, O. V.; Zimin, M. V.; Golubeva, E. I.

    2017-12-01

    The tundra-taiga ecotone plays significant role in northern ecosystems. Due to global climatic changes, the vegetation of the ecotone is the key object of many remote-sensing studies. The interpretation of vegetation and nonvegetation objects of the tundra-taiga ecotone on satellite imageries of a moderate resolution is complicated by the difficulty of extracting these objects from the spectral and spatial mixtures within a pixel. This article describes a method for the subpixel classification of Terra ASTER satellite image for vegetation mapping of the tundra-taiga ecotone in the Tuliok River, Khibiny Mountains, Russia. It was demonstrated that this method allows to determine the position of the boundaries of ecotone objects and their abundance on the basis of quantitative criteria, which provides a more accurate characteristic of ecotone vegetation when compared to the per-pixel approach of automatic imagery interpretation.

  4. Additive partitioning of testate amoeba species diversity across habitat hierarchy within the pristine southern taiga landscape (Pechora-Ilych Biosphere Reserve, Russia).

    PubMed

    Tsyganov, Andrey N; Komarov, Alexander A; Mitchell, Edward A D; Shimano, Satoshi; Smirnova, Olga V; Aleynikov, Alexey A; Mazei, Yuri A

    2015-02-01

    In order to better understand the distribution patterns of terrestrial eukaryotic microbes and the factors governing them, we studied the diversity partitioning of soil testate amoebae across levels of spatially nested habitat hierarchy in the largest European old-growth dark coniferous forest (Pechora-Ilych Biosphere Reserve; Komi Republic, Russia). The variation in testate amoeba species richness and assemblage structure was analysed in 87 samples from six biotopes in six vegetation types using an additive partitioning procedure and principal component analyses. The 80 taxa recorded represent the highest value of species richness for soil testate amoebae reported for taiga soils so far. Our results indicate that testate amoeba assemblages were highly aggregated at all levels and were mostly controlled by environmental factors rather than dispersal processes. The variation in species diversity of testate amoebae increased from the lowest to the highest hierarchical level. We conclude that, similarly to macroscopic organisms, testate amoeba species richness and community structure are primarily controlled by environmental conditions within the landscape and suggest that metacommunity dynamics of free-living microorganisms are driven by species sorting and/or mass effect processes. Copyright © 2014 Elsevier GmbH. All rights reserved.

  5. Refined δ13C trend of the Dal'nyaya Taiga series of the Ura uplift (Vendian, southern part of Middle Siberia)

    NASA Astrophysics Data System (ADS)

    Rud'ko, S. V.; Petrov, P. Yu.; Kuznetsov, A. B.; Shatsillo, A. V.; Petrov, O. L.

    2017-12-01

    New data were obtained on δ13Ccarb and δ18O variations in the sequence of deposits of the Dal'nyaya Taiga series at the western and eastern flanks of the Ura anticline. The summary δ13C curve was plotted in view of the correlation of sequence-stratigraphic data of the basin analysis. A series of positive anomalies was found within the succession. Alternatives for global chemostratigraphic correlation of the Dal'nyaya Taiga series of the Ura uplift were considered.

  6. Summer foods of lesser scaup in subarctic taiga

    USGS Publications Warehouse

    Bartonek, J.C.; Murdy, H.W.

    1970-01-01

    Twenty-five adult and 38 juvenile lesser scaup (Aythya affinis) that were collected in taiga north of Great Slave Lake, Northwest Territories, had eaten almost entirely animal material (99 i?? 1 per cent, P < 0.05). Juveniles collected in mid-summer had tended to feed on free-swimming organisms such as Chaoborinae and Conchostraca; whereas juveniles collected in late summer had tended to feed, as did adults in June, on bottom-associated organisms such as amphipods, odonates, and corixids. Sampling aquatic organisms concomitantly with collecting ducks revealed that seeds, copepods, and cladocerans were seldom or never eaten; most other organisms were consumed in proportions that were not significantly different (P < 0.05) from those in the collected samples.

  7. Snow distribution and heat flow in the taiga

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sturm, M.

    1992-05-01

    The trees of the taiga intercept falling snow and cause it to become distributed in an uneven fashion. Around aspen and birch, cone-shaped accumulations form. Beneath large spruce trees, the snow cover is depleted, forming a bowl-shaped depression called a tree well. Small spruce trees become covered with snow, creating cavities that funnel cold air to the snow/ground interface. The depletion of snow under large spruce trees results in greater heat loss from the ground. A finite difference model suggests that heat flow from tree wells can be more than twice that of undisturbed snow. In forested watersheds, this increasemore » can be a significant percentage of the total winter energy exchange.« less

  8. NDVI dynamics of the taiga zone in connection with modern climate changes

    NASA Astrophysics Data System (ADS)

    Bobkov, A.; Panidi, E.; Torlopova, N.; Tsepelev, V.

    2015-04-01

    This research is dedicated to the investigation of the relations between the XXI century climate changes and Normalized Difference Vegetation Index (NDVI) variability of the taiga zone. For this purposes was used the observations of vegetation variability on the test area located nearby Syktyvkar city (Komi Republic, Russia), 16-day averages of NDVI data derived from TERRA/MODIS space imagery (spatial resolution is about 250 meters), and the air temperature and precipitation observations from Syktyvkar meteorological station. The research results confirmed the statistically significant positive correlation between NDVI and air temperature for all vegetation types of the test area, for both spring and autumn seasons. The weakest correlation was found for coniferous forest, namely, pine forest on poor soils, and the strongest correlation was found for meadows and bogs. Additionally the map of NDVI trends of the test area shows that the sectors of greatest positive trend located on the territories with non-forest cover, and as a result, the positive trend of air temperature is indicated most brightly on vegetation of non-forest lands. Thereby these lands can serve as climate changes indicator in the investigated region. The study was partially supported by Russian Foundation for Basic Research (RFBR), research project No. 14-05-00858 a.

  9. Mapping of West Siberian taiga wetland complexes using Landsat imagery: implications for methane emissions

    NASA Astrophysics Data System (ADS)

    Evgenievna Terentieva, Irina; Vladimirovich Glagolev, Mikhail; Dmitrievna Lapshina, Elena; Faritovich Sabrekov, Alexandr; Maksyutov, Shamil

    2016-08-01

    High-latitude wetlands are important for understanding climate change risks because these environments sink carbon dioxide and emit methane. However, fine-scale heterogeneity of wetland landscapes poses a serious challenge when generating regional-scale estimates of greenhouse gas fluxes from point observations. In order to reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the taiga zone of The West Siberia Lowland (WSL) on a scene-by-scene basis using a supervised classification of Landsat imagery. Training data consist of high-resolution images and extensive field data collected at 28 test areas. The classification scheme aims at supporting methane inventory applications and includes seven wetland ecosystem types comprising nine wetland complexes distinguishable at the Landsat resolution. To merge typologies, mean relative areas of wetland ecosystems within each wetland complex type were estimated using high-resolution images. Accuracy assessment based on 1082 validation polygons of 10 × 10 pixel size indicated an overall map accuracy of 79 %. The total area of the WSL wetlands and water bodies was estimated to be 52.4 Mha or 4-12 % of the global wetland area. Ridge-hollow complexes prevail in WSL's taiga zone accounting for 33 % of the total wetland area, followed by pine bogs or "ryams" (23 %), ridge-hollow-lake complexes (16 %), open fens (8 %), palsa complexes (7 %), open bogs (5 %), patterned fens (4 %), and swamps (4 %). Various oligotrophic environments are dominant among wetland ecosystems, while poor fens cover only 14 % of the area. Because of the significant change in the wetland ecosystem coverage in comparison to previous studies, a considerable reevaluation of the total CH4 emissions from the entire region is expected. A new Landsat-based map of WSL's taiga wetlands provides a benchmark for validation of coarse-resolution global land cover products and wetland data sets in high latitudes.

  10. Quantitative assessment of pedodiversity and soil erosion within a karst sinkhole in the dry steppe subzone

    NASA Astrophysics Data System (ADS)

    Smirnova, M. A.; Gennadiev, A. N.

    2017-08-01

    A detailed study of the soil cover of a sinkhole (300 m2) in the dry steppe landscape of the Bogdinsk-Baskunchak Natural Reserve in Astrakhan oblast has been performed, and the factors of its differentiation have been analyzed. The indices of pedodiversity have been calculated and compared for karst sinkholes in the dry steppe and northern taiga landscapes. Quantitative parameters of the lateral migration of solid soil substances on the slopes of the sinkhole have been determined. The rate of soil erosion decreases from the slope of southern aspect to the slopes of western, northern, and eastern aspects. On the average, it is estimated at 0.4 mm/yr. The average rate of accumulation of solid substances on the lower parts of the slopes and in the bottom of the sinkhole reaches 0.74 mm/yr. A comparative analysis of the soil properties attests to their dependence on the particular position of a given soil within the sinkhole. Downward the slopes of the sinkhole, full-profile brown arid soils (Cambic Calcisols) are replaced by sierozem-like soils (Haplic Calcisols), light-humus poorly developed soils (Luvisols), lithozems (Leptosols), and stratified soils (stratozems, or Colluvic Regosols). The soils within the upper ring-shape soil microzone are more diverse and contrasting with respect to their morphological, physical, chemical, and physicochemical properties. The degree of soil contrasts decreases down the slopes of the sinkhole towards its bottom. The studied sinkhole is characterized by considerable pedodiversity. Quantitative parameters of pedodiversity for the sinkhole in the dry steppe zone are higher than those form the sinkholes in the northern taiga zone.

  11. [Migration in soil and accumulation in plants of peaceful nuclear explosion products in Perm region].

    PubMed

    Raskosha, N G; Shuktova, I I

    2015-01-01

    The data on the migration capacity in soil and accumulation of 238Pu, 239, 240Pu, 137Cs and 90Sr by plants in the area of a peaceful nuclear explosion located in the taiga zone are presented. The influence of the soil parameters on the distribution and transformation forms of the radionuclides in the podzolic soil profile was studied. The major amounts of man-made radionuclides were found in the matter of the ground lip. The accumulation parameters of pollutants by plants were the highest for the leaves, young branches and conifer of trees.

  12. The influence of plant communities on postagrogenic soils in the middle taiga zone.

    NASA Astrophysics Data System (ADS)

    Churilin, Nikita; Churilina, Alexandra; Chizhikova, Natalia; Varlamov, Evgeny

    2016-04-01

    At the present time there are many abandoned postagrogenic croplands in Russia. These lands are gradually involved in natural plant succession, which has affect on the properties of the soil. Therefore, the study of these soils is one of the important trends in the Russian soil science. The aim of the study was to identify possible trends in soil changes after a long anthropogenic impact on a base of morphological, chemical and some physical properties of postagrogenic soils under different plant communities. Soils were sampled in the south of Arkhangelsk region, Ustyansky district, near Akichkin Pochinok village. Soils are formed on clay moraine of Moscow glaciation with klastolits. All soil profiles were dug on interfluve. We determined chemical composition (pH, CaCO3%, organic carbon, CEC, F2O3 (Mer-Jackson), NPK), physical characteristics (particle size distribution, bulk density of the soil) and XRD of <1μm, 1-5μm, 5-10μm fractions from soils. We selected 4 plant communities on different stages of succession: upland meadow with domination of sod grasses (Phleum pratense, Agrostis tenuis), 16 years old birch forest where dominatants are herbaceous plants such as Poa sp., Chamerion angustiflium, Agrostis tenuis, 16 years old spruce forest with no herbaceous vegetation and 70 years old bilberry spruce forest with domination of Vaccinium myrtillus and Vaccinium vitis-idaea. To study postagrogenic soils we made 4 soil profiles under these plant communities. All profiles have evidence of anthraquic horizon and they have plough pan on a depth of 20-24 cm (confirmed by bulk density). The plowed horizon is better expressed in soils under the meadow. All 4 soils are characterized by presence of Fe-Mn segregations throughout the profiles, particle size distribution heaving to the lower horizon and residual albic horizon. We identified following soils: Albic Dystric Retisol (Cutanic Abrubptic Loamic) under the old spruce, Dystric Retisol (Cutanic Loamic Anthraquic) in

  13. [POLYMORPHISM IN THE PHENOTYPIC STRUCTURE OF A POPULATION OF TAIGA TICK AND ITS EPIDEMIOLOGICAL SIGNIFICANCE].

    PubMed

    Morozov, I M; Alekseev, A N; Dubinina, E V; Nikitin, A Ya; Melnikova, O V; Andaev, E I

    2015-01-01

    The paper presents the results of 10-year (2005-2014) observations of an Ixodespersulcatus Schulze population. The purpose of this investigation was to trace long-term changes in the structure of the taiga tick population from the proportion of specimens with external skeletal anomalies and to assess a relationship between the pattern of imago phenotypic variation and the virus percentage of a carrier. There were a total of reports of the external skeletal structure of 1123 females gathered from plants to a flag in an area at 43 km from the Baikal Road connecting Irkutsk and the settlement of Listvyanka (Irkutsk Region). The proportion of specimens with anomalies averaged 37.8 +/- 1.88%. Four-to-seven varying anomalies were annually recorded. There was a preponderance of scutum impairment (an average of 17.0 +/- 3.08% of all females) that was a conglomerate of prominences and indentations along the entire clypeus surface and that was denoted P9. The nature of a change in the proportion of ticks with two anomalies (average monthly registration rate, 2.5 +/- 0.66%) is exhibited by three-year high-frequency oscillations whereas the specimens with P9 anomalies fail to show so clear cycling. The percentage of virus-containing taiga ticks was individually determined estimating the level of tick-borne encephalitis virus antigen by an enzyme immunoassay. A total of 4022 ticks were examined. The male and female data were pooled. There was a positive correlation between the change in the proportion of females with P9 anomaly and the infection of ticks in the examined population (Spearman's correlation coefficient, 0.88; P < 0.01). This supports the earlier observation of the greater epidemiological significance of the imago of a taiga tick with external skeletal anomalies particularly with considerably marked ones.

  14. [Etiological structure of complex Ixodes tickborne borreliosis natural foci of southern taiga].

    PubMed

    Korenberg, É I; Nefedova, V V; Gorelova, N B; Kovalevskiĭ, Iu V; Fadeeva, I A; Golubova, D A

    2011-01-01

    89 primary isolates of B. garinii and 72 B. afzelii from different developmental phases of I. persulcatus, I. trianguliceps and form small mammalian hosts of Borrelia were obtained at an area of ca. 30 km2 located in low-mountain southern taiga forests (Perm region). The area provides home for two Borrelia species (B. garinii and B. afzeli) and their natural carrier Ixodes persulcatus. 23 isolate of B.garnii were obtained from skin biopsies and blood samples taken in patients with borreliosis. The isolates were studied by sequencing rrf(5S)-rrr(23S) spacer. The term genetic variant (genovariant) is proposed for the totality of isolates belonging to a given genetic subgroup of the concrete genospecies and having a similar nucleotide sequence of rrf(5S)-rrr(23S) spacer or other conservative genomic sequence. Genovariant is ths smallest intraspecies taxonomic unit in widespread Borrelia pathogenic for man. Several genovariants of B. garinii and B. afzelii may simultaneously occur in combined parasitic systems formed by these spirochetal agents of Ixodes tick-borne borreliosis. Such natural foci in southern taiga of the Perm region have a complicated etiological structure due to the presence of 14 genovariants of Borrelia belonging to the two above genetic subgroups. Specific genovariants occur annually but with different frequency. They are lacking in host-specificity.

  15. Influence of water table on carbon dioxide, carbon monoxide, and methane fluxes from taiga bog microcosms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Funk, D.W.; Pullmann, E.R.; Peterson, K.M.

    1994-09-01

    Hydrological changes, particularly alterations in water table level, may largely overshadow the more direct effects of global temperature increase upon carbon cycling in arctic and subarctic wetlands. Frozen cores (n=40) of intact soils and vegetation were collected from a bog near Fairbanks, Alaska, and fluxes of CO{sub 2}, CH{sub 4}, and Co in response to water table variation were studied under controlled conditions in the Duke University phytotron. Core microcosms thawed to a 20-cm depth over 30 days under a 20 hour photoperiod with a day/night temperature regime of 20/10{degrees}C. After 30 days the water table in 20 microcosms wasmore » decreased from the soil surface to -15 cm and maintained at the soil surface in 20 control cores. Outward fluxes of CO{sub 2} (9-16 g m{sup -2}d{sup -1}) and CO (3-4 mg m{sup -2}d{sup -1}) were greatest during early thaw and decreased to near zero for both gases before the water table treatment started. Lower water table tripled CO{sub 2} flux to the atmosphere when compared with control cores. Carbon monoxide was emitted at low rates from high water table cores and consumed by low water table cores. Methane fluxes were low (<1 mg m{sup -2}d{sup -1}) in all cores during thaw. High water table cores increased CH{sub 4} flux to 8-9 mg m{sup -2}d{sup -1} over 70 days and remained high relative to the low water table cores (<0.74 mg m{sup -2}d{sup -1}). Although drying of wetland taiga soils may decrease CH{sub 4} emissions to the atmosphere, the associated increase in CO{sub 2} due to aerobic respiration will likely increase the global warming potential of gas emissions from these soils. 43 refs., 4 figs.« less

  16. [EFFECT OF PYRETHROIDS ON TAIGA TICKS (IXODES PERSULCATUS IXODIDAE)].

    PubMed

    Germant, O M; Shashina, N I

    2016-01-01

    Nonspecific prevention of infections, the agents of which are transmitted by Ixodes ticks, is aimed at stopping the suction of the ticks to humans and is substantially based one the use of acaricides. The most interesting group of compounds to be used to individually protect humans is pyrethroids that cause different nerve conduction disturbances in the ticks, which result in their paralysis and death more significantly rapidly than the compounds from other chemical groups. The effect of 8 pyrethroids was investigated when the taiga ticks were in contact with the tissue treated with the compounds. The relationship of the chemical structure of pyrethroids with their acaricidal activity was analyzed from motor activity values and knockdown time. The test pyreithroids, in order of decreasing acaricidal activity, are imiprothrin cyphenothrin, cyfluthrin, alpha-cyperamethrin, zeta-cyperimethrin fenothrin, flumethrin.

  17. Acidification of forest soil in Russia: From 1893 to present

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.

    2003-01-02

    It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations similar to 100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases inmore » precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place.« less

  18. Acidification of forest soil in Russia: From 1893 to present

    USGS Publications Warehouse

    Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.; Bobrov, A.A.; Torn, M.S.; Harden, J.W.

    2004-01-01

    It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations ???100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases in precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place. Copyright 2004 by the American Geophysical Union.

  19. Soil temperature of peatland landscapes as a factor in the development of exogenous processes of biogenic relief formation in engineering development of territory

    NASA Astrophysics Data System (ADS)

    Korkin, S.; Talyneva, O.; Kail, E.

    2018-03-01

    In the presented work we consider mire landscapes in the context of temperature monitoring. The mire landscapes in engineering development of the territory are very sensitive to anthropogenic impact that leads to a change in surface conditions, changes in natural succession and, as a rule, to changes in soil temperature and properties, which in turn may develop a complex of hostile geodynamic processes. For this study we used recording systems for field measurement of peat and subsoil temperatures. The measurements were made in two key areas: the territory of the north-taiga landscapes of Western Siberia (the Siberian Ridges), and the territory of the middle-taiga landscapes of Western Siberia (the Ob middle-river lowland). The paper analyses the data obtained from five observation sites (3, 5, 5a, 6 and 8) referred to hydromorphic landscapes. For the territory of the Siberian Ridges the 5-year average soil temperature was 3°C. For the Ob middle-river lowland the 6-year average soil temperature was 4.2°C. The annual soil temperature in the period 2015-2016 for Site 5a (man-disturbed area) was 8.3°C at all depths, which is 3.8°C higher than in a natural bog (Site 5 was a control area).

  20. Response of middle-taiga permafrost landscapes of Central Siberia to global warming in the late 20th and early 21st centuries

    NASA Astrophysics Data System (ADS)

    Medvedkov, Alexey A.

    2016-11-01

    In this paper, regional features of a climatogenic response of the middle-taiga permafrost landscapes of Central Siberia, as well as corresponding transformations of the exodynamic processes, are considered. Lithological-geomorphologic and landscape- geocryological data are analyzed with large amounts of actual data and results of monitoring surveys. Specific features of an ecotone localization of middle-taiga permafrost landscapes and their typical physiognomic characteristics are described. A comprehensive investigation of representative key sites makes it possible to discover the response of different types of permafrost landscapes to regional climate warming. A rapid increase in the active layer depth, slower creep, transformations of the moving kurums, intensive solifluction, and a local replacement of solifluction by landslides-earthflows are revealed within ecotone landscapes of the cryolithozone.

  1. Development of an adaptive harvest management program for Taiga bean geese

    USGS Publications Warehouse

    Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper

    2016-01-01

    This report describes recent progress in specifying the elements of an adaptive harvest program for taiga bean goose. It describes harvest levels appropriate for first rebuilding the population of the Central Management Unit and then maintaining it near the goal specified in the AEWA International Single Species Action Plan (ISSAP). This report also provides estimates of the length of time it would take under ideal conditions (no density dependence and no harvest) to rebuild depleted populations in the Western and Eastern Management Units. We emphasize that our estimates are a first approximation because detailed demographic information is lacking for taiga bean geese. Using allometric relationships, we estimated parameters of a thetalogistic matrix population model. The mean intrinsic rate of growth was estimated as r = 0.150 (90% credible interval: 0.120 – 0.182). We estimated the mean form of density dependence as   2.361 (90% credible interval: 0.473 – 11.778), suggesting the strongest density dependence occurs when the population is near its carrying capacity. Based on expert opinion, carrying capacity (i.e., population size expected in the absence of hunting) for the Central Management Unit was estimated as K  87,900 (90% credible interval: 82,000 – 94,100). The ISSAP specifies a population goal for the Central Management Unit of 60,000 – 80,000 individuals in winter; thus, we specified a preliminary objective function as one which would minimize the difference between this goal and population size. Using the concept of stochastic dominance to explicitly account for uncertainty in demography, we determined that optimal harvest rates for 5, 10, 15, and 20-year time horizons were h = 0.00, 0.02, 0.05, and 0.06, respectively. These optima represent a tradeoff between the harvest rate and the time required to achieve and maintain a population size within desired bounds. We recognize, however, that regulation of absolute harvest rather than

  2. Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica

    PubMed Central

    Dulamsuren, Choimaa; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

    2010-01-01

    Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia’s forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140–490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century. PMID:20571829

  3. Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica.

    PubMed

    Dulamsuren, Choimaa; Hauck, Markus; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

    2010-08-01

    Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia's forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140-490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century.

  4. Windthrow and fallow-forest successions impacts in soil carbon stocks and GHG fluxes spatial variability and dynamics in the Central Russia' reserve spruce ecosystems

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan; Ivanov, Alexey; Komarova, Tatyana; Valentini, Riccardo

    2015-04-01

    High spatial and temporal variability is mutual feature for most forest soils that is especially obvious in case of their carbon stocks and GHG fluxes. This phenomenon is generally well-known but not so often becomes the object of special precision investigation in detail and small scales so there are still serious gaps in its principal factors understanding due to their high bioclimatic, regional, landscape, tree species and temporal variability. Southern taiga is one of the most environmentally important world zonal forest ecosystems due to its still comparatively intensive carbon biogeochemical cycle and huge area in the northern Eurasia with strong anthropogenic impacts by Western & Central European and Southern & Eastern Asian regions. Central Forest Biospheric Reserve (Tver region, 360 km to North-West from Moscow) is the principal southern-taiga reserve in the European territory of Russia. Since start of its research activity in 1939 the reserve became the regional center of mature spruce ecosystem structure and dynamics investigation. In 1970-1980-s there have been done complex investigations of windthrow soil patterns and fallow-forest successions. Since middle of 1990-s the ecosystem-level GHG fluxes have been observed by eddy covariance method. Since 2012 the detailed year-round monitoring is running in the southern-taiga zonal station of the regional system RusFluxNet with especial attention on the soil carbon stocks and GHG fluxes spatial variability and dynamics due to windthrow and fallow-forest successions (in frame of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266). Soil carbon dynamics is investigated in decades-hundred-year chronosequences of dominated parcels and different-size windthrow soil cover patterns, including direct investigation during last 33 years with detailed mapping, soil profile morphometrics and bulk density, morphogenetic and statistical analysis of mass data. Morphogenetic analysis of microrelief, soil profile

  5. Diversity of the soil biota in burned areas of southern taiga forests (Tver oblast)

    NASA Astrophysics Data System (ADS)

    Gongalsky, K. B.; Zaitsev, A. S.; Korobushkin, D. I.; Saifutdinov, R. A.; Yazrikova, T. E.; Benediktova, A. I.; Gorbunova, A. Yu.; Gorshkova, I. A.; Butenko, K. O.; Kosina, N. V.; Lapygina, E. V.; Kuznetsova, D. M.; Rakhleeva, A. A.; Shakhab, S. V.

    2016-03-01

    Relations between soil biota diversity and its contribution to the performance of some ecosystem functions were assessed based on the results obtained in undisturbed and burned spruce forests near the Central Forest Nature Biosphere Reserve (Tver oblast). In August 2014, in two 4-year-old burned areas, abiotic parameters of the soils, indicators of the state of the microbial communities, the number, taxonomic diversity, and the abundance of the main groups of soil invertebrates (testate amoebae, nematodes, enchytraeids, mites, collembolans, and the mesofauna as a whole) were determined. In the soils of the burned areas, higher CO2, CH4, and N2O emissions were observed. The number of bacterial cells remained similar, and the total length of active mycelium was not significantly different. All this implies a certain intensification of biogenic processes promoting the mobilization of carbon and nitrogen after fire. The number of most of the groups of soil animals was lower (not always significantly) in the burned area than that in the soils of the undisturbed forests. The changes in the taxonomic diversity were specific for each taxon studied. Overall, the diversity of invertebrates was related to the litter thickness. However, the high taxonomic diversity of soil fauna did not always correspond to the active functioning of the ecosystem. Thus, for some taxa, a quite close correlation was found, for instance, between the total number of species (of testate amoebae in particular) and the berry crop, as well as between the soil mesofauna population and the dead wood stock. The total diversity of the investigated taxa included in the detrital trophic web was the most reliable indicator of the carbon stock in the burned areas.

  6. Extremophilic and extremotolerant actinomycetes in different soil types

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Manucharova, N. A.; Zvyagintsev, D. G.

    2011-04-01

    Problems on the resistance of soil actinomycetes to various environmental factors (pH, salinity, temperature, and moisture) are discussed. Actinomycetes as a special group of prokaryotes were revealed to have a greater range of tolerance to these factors than was thought earlier. The regularities of the distribution of extremophilic and extremotolerant actinomycetes developing in unusual for mycelial bacteria conditions, their structural-functional characteristics, and their taxonomic composition were determined. The predominance of acidophilic representatives of the Micromonospora genus in acid soils (typical peat, soddy-podzolic, and taiga podzol) and the haloalkaliphilic Streptomyces pluricilirescens and S. prunicolor species in desert saline soils are shown. The specific features of the actinomycete complexes on thermal fields of the weakly developed stratified volcanic soils are described. In these complexes, the thermophilic forms were represented only by species of the Micromonospora genus; and the mesophilic forms, by Microbispora species. In the periodically heated desert soils, among the thermophilic actinomycetes, representatives of rare Actinomadura, Saccharopolyspora and Streptosporangium genera along with Streptomyces species were indicated. The mechanisms of the resistance of the actinomycetes to the extreme environmental conditions are discussed.

  7. Digital soil map of the Ussuri River basin

    NASA Astrophysics Data System (ADS)

    Bugaets, A. N.; Pschenichnikova, N. F.; Tereshkina, A. A.; Krasnopeev, S. M.; Gartsman, B. I.; Golodnaya, O. M.; Oznobikhin, V. I.

    2017-08-01

    On the basis of digital soil, topographic, and geological maps; raster topography model; forestry materials; and literature data, the digital soil map of the Ussuri River basin (24400 km2) was created on a scale of 1: 100000. To digitize the initial paper-based maps and analyze the results, an ESRI ArcGIS Desktop (ArcEditor) v.10.1 (http://www.esri.com) and an open-code SAGA GIS v.2.3 (System for Automated Geoscientific Analyses, http://www.saga-gis.org) were used. The spatial distribution of soil areas on the obtained digital soil map is in agreement with modern cartographic data and the SRTM digital elevation model (SRTM DEM). The regional soil classification developed by G.I. Ivanov was used in the legend to the soil map. The names of soil units were also correlated with the names suggested in the modern Russian soil classification system. The major soil units on the map are at the soil subtypes that reflect the entire vertical spectrum of soils in the south of the Far East of Russia (Primorye region). These are mountainous tundra soils, podzolic soils, brown taiga soils, mountainous brown forest soils, bleached brown soils, meadow-brown soils, meadow gley soils, and floodplain soils). With the help of the spatial analysis function of GIS, the comparison of the particular characteristics of the soil cover with numerical characteristics of the topography, geological composition of catchments, and vegetation cover was performed.

  8. MODIS Tree Cover Validation for the Circumpolar Taiga-Tundra Transition Zone

    NASA Technical Reports Server (NTRS)

    Montesano, P. M.; Nelson, R.; Sun, G.; Margolis, H.; Kerber, A.; Ranson, K. J.

    2009-01-01

    A validation of the 2005 500m MODIS vegetation continuous fields (VCF) tree cover product in the circumpolar taiga-tundra ecotone was performed using high resolution Quickbird imagery. Assessing the VCF's performance near the northern limits of the boreal forest can help quantify the accuracy of the product within this vegetation transition area. The circumpolar region was divided into longitudinal zones and validation sites were selected in areas of varying tree cover where Quickbird imagery is available in Google Earth. Each site was linked to the corresponding VCF pixel and overlaid with a regular dot grid within the VCF pixel's boundary to estimate percent tree crown cover in the area. Percent tree crown cover was estimated using Quickbird imagery for 396 sites throughout the circumpolar region and related to the VCF's estimates of canopy cover for 2000-2005. Regression results of VCF inter-annual comparisons (2000-2005) and VCF-Quickbird image-interpreted estimates indicate that: (1) Pixel-level, inter-annual comparisons of VCF estimates of percent canopy cover were linearly related (mean R(sup 2) = 0.77) and exhibited an average root mean square error (RMSE) of 10.1 % and an average root mean square difference (RMSD) of 7.3%. (2) A comparison of image-interpreted percent tree crown cover estimates based on dot counts on Quickbird color images by two different interpreters were more variable (R(sup 2) = 0.73, RMSE = 14.8%, RMSD = 18.7%) than VCF inter-annual comparisons. (3) Across the circumpolar boreal region, 2005 VCF-Quickbird comparisons were linearly related, with an R(sup 2) = 0.57, a RMSE = 13.4% and a RMSD = 21.3%, with a tendency to over-estimate areas of low percent tree cover and anomalous VCF results in Scandinavia. The relationship of the VCF estimates and ground reference indicate to potential users that the VCF's tree cover values for individual pixels, particularly those below 20% tree cover, may not be precise enough to monitor 500m pixel

  9. Succession after stand replacing disturbances by fire, wind throw, and insects in the dark Taiga of Central Siberia.

    PubMed

    Schulze, E-D; Wirth, C; Mollicone, D; Ziegler, W

    2005-11-01

    The dark taiga of Siberia is a boreal vegetation dominated by Picea obovata, Abies sibirica, and Pinus sibirica during the late succession. This paper investigates the population and age structure of 18 stands representing different stages after fire, wind throw, and insect damage. To our knowledge, this is the first time that the forest dynamics of the Siberian dark taiga is described quantitatively in terms of succession, and age after disturbance, stand density, and basal area. The basis for the curve-linear age/diameter relation of trees is being analyzed. (1) After a stand-replacing fire Betula dominates (4,000 trees) for about 70 years. Although tree density of Betula decreases rapidly, basal area (BA) reached >30 m2/ha after 40 years. (2) After fire, Abies, Picea, and Pinus establish at the same time as Betula, but grow slower, continue to gain height and eventually replace Betula. Abies has the highest seedling number (about 1,000 trees/ha) and the highest mortality. Picea establishes with 100-400 trees/ha, it has less mortality, but reached the highest age (>350 years, DBH 51 cm). Picea is the most important indicator for successional age after disturbance. Pinus sibirica is an accompanying species. The widely distributed "mixed boreal forest" is a stage about 120 years after fire reaching a BA of >40 m2/ha. (3) Wind throw and insect damage occur in old conifer stands. Betula does not establish. Abies initially dominates (2,000-6,000 trees/ha), but Picea becomes dominant after 150-200 years since Abies is shorter lived. (4) Without disturbance the forest develops into a pure coniferous canopy (BA 40-50 m2/ha) with a self-regenerating density of 1,000 coniferous canopy trees/ha. There is no collapse of old-growth stands. The dark taiga may serve as an example in which a limited set to tree species may gain dominance under certain disturbance conditions without ever getting monotypic.

  10. Natural resource inventory and monitoring for Ulaan Taiga Specially Protected Areas—An assessment of needs and opportunities in northern Mongolia

    USGS Publications Warehouse

    Moore, Peggy E.; Meyer, Joseph B.; Chow, Leslie S.

    2017-03-10

    Between 1997 and 2011, Mongolia established three specially protected areas in the north-central part of the country to protect various high-value resources. These areas are jointly referred to as the Ulaan Taiga Specially Protected Areas. In accordance with the goals of the draft general management plan, this report identifies options for initiating an inventory and monitoring program for the three protected areas. Together, the three areas comprise over 1.5 million hectares of mountainous terrain west of Lake Hovsgol and bordering the Darkhad Valley. The area supports numerous rare ungulates, endangered fish, and over 40 species of threatened plants. Illegal mining, illegal logging, and poaching pose the most immediate threats to resources. As a first step, a review of published literature would inform natural resource management at the Ulaan Taiga Specially Protected Areas because it would inform other inventories.Vegetation classification and mapping also would inform other inventory efforts because the process incorporates geographic analysis to identify environmental gradients, fine-scale sampling that captures species composition and structure, and landscape-scale results that represent the variety and extent of habitats for various organisms. Mapping using satellite imagery reduces the cost per hectare.Following a determination of existing knowledge, field surveys of vertebrates and vascular plants would serve to build species lists and fill in gaps in existing knowledge. For abiotic resources, a focus on monitoring air quality, evaluating and monitoring water quality, and assembling and storing weather data would provide information for correlating resource response status with changing environmental conditions.Finally, we identify datasets that, if incorporated into a geographic information system, would inform resource management. They include political boundaries, infrastructure, topography, surficial geology, hydrology, fire history, and soils.In terms

  11. Comparative phylogeography and demographic history of the wood lemming (Myopus schisticolor): implications for late Quaternary history of the taiga species in Eurasia.

    PubMed

    Fedorov, V B; Goropashnaya, A V; Boeskorov, G G; Cook, J A

    2008-01-01

    The association between demographic history, genealogy and geographical distribution of mitochondrial DNA cytochrome b haplotypes was studied in the wood lemming (Myopus schisticolor), a species that is closely associated with the boreal forest of the Eurasian taiga zone from Scandinavia to the Pacific coast. Except for a major phylogeographic discontinuity (0.9% nucleotide divergence) in southeastern Siberia, only shallow regional genetic structure was detected across northern Eurasia. Genetic signs of demographic expansions imply that successive range contractions and expansions on different spatial scales represented the primary historical events that shaped geographical patterns of genetic variation. Comparison of phylogeographic structure across a taxonomically diverse array of other species that are ecologically associated with the taiga forest revealed similar patterns and identified two general aspects. First, the major south-north phylogeographic discontinuity observed in five out of six species studied in southeastern Siberia and the Far East implies vicariant separation in two different refugial areas. The limited distribution range of the southeastern lineages provides no evidence of the importance of the putative southeastern refugial area for postglacial colonization of northern Eurasia by boreal forest species. Second, the lack of phylogeographic structure associated with significant reciprocal monophyly and genetic signatures of demographic expansion in all nine boreal forest animal species studied to date across most of northern Eurasia imply contraction of each species to a single refugial area during the late Pleistocene followed by range expansion on a continental scale. Similar phylogeographic patterns observed in this taxonomically diverse set of organisms with different life histories and dispersal potentials reflect the historical dynamics of their shared environment, the taiga forest in northern Eurasia.

  12. Diagnosis of the hydrology of a small Arctic basin at the tundra-taiga transition using a physically based hydrological model

    NASA Astrophysics Data System (ADS)

    Krogh, Sebastian A.; Pomeroy, John W.; Marsh, Philip

    2017-07-01

    A better understanding of cold regions hydrological processes and regimes in transitional environments is critical for predicting future Arctic freshwater fluxes under climate and vegetation change. A physically based hydrological model using the Cold Regions Hydrological Model platform was created for a small Arctic basin in the tundra-taiga transition region. The model represents snow redistribution and sublimation by wind and vegetation, snowmelt energy budget, evapotranspiration, subsurface flow through organic terrain, infiltration to frozen soils, freezing and thawing of soils, permafrost and streamflow routing. The model was used to reconstruct the basin water cycle over 28 years to understand and quantify the mass fluxes controlling its hydrological regime. Model structure and parameters were set from the current understanding of Arctic hydrology, remote sensing, field research in the basin and region, and calibration against streamflow observations. Calibration was restricted to subsurface hydraulic and storage parameters. Multi-objective evaluation of the model using observed streamflow, snow accumulation and ground freeze/thaw state showed adequate simulation. Significant spatial variability in the winter mass fluxes was found between tundra, shrubs and forested sites, particularly due to the substantial blowing snow redistribution and sublimation from the wind-swept upper basin, as well as sublimation of canopy intercepted snow from the forest (about 17% of snowfall). At the basin scale, the model showed that evapotranspiration is the largest loss of water (47%), followed by streamflow (39%) and sublimation (14%). The models streamflow performance sensitivity to a set of parameter was analysed, as well as the mean annual mass balance uncertainty associated with these parameters.

  13. Effects of soil freezing and thawing on vegetation carbon density in Siberia: A modeling analysis with the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM)

    NASA Astrophysics Data System (ADS)

    Beer, C.; Lucht, W.; Gerten, D.; Thonicke, K.; Schmullius, C.

    2007-03-01

    The current latitudinal gradient in biomass suggests a climate-driven limitation of biomass in high latitudes. Understanding of the underlying processes, and quantification of their relative importance, is required to assess the potential carbon uptake of the biosphere in response to anticipated warming and related changes in tree growth and forest extent in these regions. We analyze the hydrological effects of thawing and freezing of soil on vegetation carbon density (VCD) in permafrost-dominated regions of Siberia using a process-based biogeochemistry-biogeography model, the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). The analysis is based on spatially explicit simulations of coupled daily thaw depth, site hydrology, vegetation distribution, and carbon fluxes influencing VCD subject to climate, soil texture, and atmospheric CO2 concentration. LPJ represents the observed high spring peak of runoff of large Arctic rivers, and simulates a realistic fire return interval of 100 to 200 years in Siberia. The simulated VCD changeover from taiga to tundra is comparable to inventory-based information. Without the consideration of freeze-thaw processes VCD would be overestimated by a factor of 2 in southern taiga to a factor of 5 in northern forest tundra, mainly because available soil water would be overestimated with major effects on fire occurrence and net primary productivity. This suggests that forest growth in high latitudes is not only limited by temperature, radiation, and nutrient availability but also by the availability of liquid soil water.

  14. Soils of Mountainous Forests and Their Transformation under the Impact of Fires in Baikal Region

    NASA Astrophysics Data System (ADS)

    Krasnoshchekov, Yu. N.

    2018-04-01

    Data on postpyrogenic dynamics of soils under mountainous taiga cedar ( Pinus sibirica) and pine ( Pinus sylvestris) forests and subtaiga-forest-steppe pine ( Pinus sylvestris) forests in the Baikal region are analyzed. Ground litter-humus fires predominating in this region transform the upper diagnostic organic soil horizons and lead to the formation of new pyrogenic organic horizons (Opir). Adverse effects of ground fires on the stock, fractional composition, and water-physical properties of forest litters are shown. Some quantitative parameters of the liquid and solid surface runoff in burnt areas related to the slope gradient, fire intensity, and the time passed after the fire are presented. Pyrogenic destruction of forest ecosystems inevitably induces the degradation of mountainous soils, whose restoration after fires takes tens of years. The products of soil erosion from the burnt out areas complicate the current situation with the pollution of coastal waters of Lake Baikal.

  15. The communities of terrestrial macrofungi in different forest types in vicinities of Khanty-Mansiysk (middle taiga zone of West Siberia).

    PubMed

    Filippova, Nina; Bulyonkova, Tatiana

    2017-01-01

    The diversity of macrofungi in the vicinities of Khanty-Mansiysk (Yugra, Russia) was surveyed using a method of permanent sampling plots. Ten plots, each consisting of a number of micro-plots, were established in several different communities ranging from old-growth mixed taiga forest to its derivatives in cutting succession and bogged areas. For more complete registration of the mycota, plots were supplemented with random walking routes directly nearby. Survey results were subjected to various quantitative analyses which allowed not only to evaluate the diversity of fungi but also to obtain valuable information on occurrence, abundance and ecology of individual species as well as community structure and its dynamics in the course of ecological succession. The paper reports the results of the first year of observations. 460 species of terrestrial macrofungi revealed in a poorly explored area in middle taiga of West Siberia. The plot-based study revealed differences between communities of terrestrial macrofungi of old coniferous forests, their after-cutting secondary formations and bogged stages. The survey allowed to reveal records of 3 species listed in the Red Data Book of Russia and 9 species listed in the Red Data Book of Yugra.

  16. Tunguska, 1908: the gas pouch and soil fluidization hypothesis

    NASA Astrophysics Data System (ADS)

    Nistor, I.

    2012-01-01

    The Siberian taiga explosion of 30 June 1908 remains one of the great mysteries of the 20th century: millions of trees put down over an area of 2200 km2 without trace of a crater or meteorite fragments. Hundred years of failed searches have followed, resulting in as many flawed hypothesis which could not offer satisfactory explanations: meteorite, comet, UFO, etc. In the author's opinion, the cause is that the energy the explorers looked for was simply not there! The author's hypothesis is that a meteoroid encountered a gas pouch in the atmosphere, producing a devastating explosion, its effects being amplified by soil fluidization.

  17. Mapping of West Siberian taiga wetland complexes using Landsat imagery: Implications for methane emissions

    NASA Astrophysics Data System (ADS)

    Terentieva, Irina; Sabrekov, Alexander; Glagolev, Mikhail; Maksyutov, Shamil

    2017-04-01

    Boreal wetlands are important for understanding climate change risks because these environments sink carbon dioxide and emit methane. The West Siberia Lowland (WSL) is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. However, fine-scale heterogeneity of wetland landscapes poses a serious challenge when generating regional-scale estimates of greenhouse gas fluxes from point observations. A number of peatland maps of the West Siberia was developed in 1970s, but their accuracy is limited. In order to reduce uncertainties at the regional scale, we mapped wetlands and water bodies in the WSL on a scene-by-scene basis using a supervised classification of Landsat imagery. Training data consisted of high-resolution images and extensive field data collected at 41 test areas. The classification scheme aimed at supporting methane inventory applications and included 7 wetland ecosystem types comprising 9 wetland complexes distinguishable at the Landsat resolution. To merge typologies, mean relative areas of wetland ecosystems within each wetland complex type were estimated using high-resolution images. Accuracy assessment based on 1082 validation polygons of 10×10 pixels indicated an overall map accuracy of 79%. The total area of the WSL wetlands and water bodies was estimated to be 70.78 Mha or 5-17% of the global wetland area. Various oligotrophic environments are dominant among wetland ecosystems, while different fens cover only 14% of the area. Taiga zone contains 75% of WSL's wetlands; their distribution was described in detail by Terentieva et al. (2016). Concerning methane emission, taiga contributes 85% to regional methane flux and tundra only 8%, however ebullition in tundra lakes was not directly measured. Elevated environments as forested bogs and ridges emit at the lowest rates of methane emission. They account for only 2% of the regional total emissions occupying almost 40% of the wetland

  18. Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nikonov, V.V.

    1981-01-01

    The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).

  19. Microbial communities in the litter of middle taiga bilberry-spruce forests

    NASA Astrophysics Data System (ADS)

    Sizonenko, T. A.; Zagirova, S. V.; Khabibullina, F. M.

    2010-10-01

    The structure of the microbial communities in the litters of middle-taiga bilberry-spruce forests was studied. It was found that ammonifying and oligonitrophilic microorganisms predominate in these communities. Two maximums in the population density of the microorganisms were observed in June and August. The number of microorganisms increased in the direction from the spruce trunks to the periphery of the crowns. The species composition of the micromycetes in the litters under the spruce crowns and within the intercrown spaces differed. The maximum population density of the fungi was found in the litter under the periphery of the spruce crowns, whereas the maximum diversity of the micromycetes was observed within the intercrown spaces. The Trichoderma, Trichosporiella, Penicillium, Paecilomyces, and Chaetomium genera were most abundant in the litters of the bilberry spruce forests. The Penicillium genus had the maximum abundance during the entire growing period, and the amount of Mycelia sterilia increased in the fall. The maximum diversity of the fungi was observed in May and June.

  20. Influence of Forest-Canopy Morphology and Relief on Spectral Characteristics of Taiga Forests

    NASA Astrophysics Data System (ADS)

    Zhirin, V. M.; Knyazeva, S. V.; Eydlina, S. P.

    2017-12-01

    The article deals with the results of a statistical analysis reflecting tendencies (trends) of the relationship between spectral characteristics of taiga forests, indicators of the morphological structure of forest canopy and illumination of the territory. The study was carried out on the example of the model forest territory of the Priangarskiy taiga region of Eastern Siberia (Krasnoyarsk krai) using historical data (forest inventory 1992, Landsat 5 TM 16.06.1989) and the digital elevation model. This article describes a method for determining the quantitative indicator of morphological structure of forest canopy based on taxation data, and the authors propose to subdivide the morphological structure into high complexity, medium complexity, and relatively simple. As a result of the research, dependences of average values of spectral brightness in near and short-wave infrared channels of a Landsat 5 TM image for dark-coniferous, light-coniferous and deciduous forests from the degree of complexity of the forest-canopy structure are received. A high level of variance and maximum brightness average values are marked in green moss (hilocominosa) dark-coniferous and various-grass (larioherbosa) dark-coniferous forests and light-coniferous forests with a complex structure of canopy. The parvifoliate forests are characterized by high values of brightness in stands with a relatively simple structure of the canopy and by a small variance in brightness of any degree of the structure of the canopy complexity. The increase in brightness for the lit slopes in comparison with shaded ones in all stands with a difficult morphological canopy structure is revealed. However, the brightness values of the lit and shaded slopes do not differ for stands with a medium complexity of the structure. It is noted that, in addition to the indicator of the forest-canopy structure, the possible impact on increasing the variance of spectral brightness for the taxation plot has a variability of the

  1. The communities of terrestrial macrofungi in different forest types in vicinities of Khanty-Mansiysk (middle taiga zone of West Siberia)

    PubMed Central

    Bulyonkova, Tatiana

    2017-01-01

    Abstract Background The diversity of macrofungi in the vicinities of Khanty-Mansiysk (Yugra, Russia) was surveyed using a method of permanent sampling plots. Ten plots, each consisting of a number of micro-plots, were established in several different communities ranging from old-growth mixed taiga forest to its derivatives in cutting succession and bogged areas. For more complete registration of the mycota, plots were supplemented with random walking routes directly nearby. Survey results were subjected to various quantitative analyses which allowed not only to evaluate the diversity of fungi but also to obtain valuable information on occurrence, abundance and ecology of individual species as well as community structure and its dynamics in the course of ecological succession. The paper reports the results of the first year of observations. New information 460 species of terrestrial macrofungi revealed in a poorly explored area in middle taiga of West Siberia. The plot-based study revealed differences between communities of terrestrial macrofungi of old coniferous forests, their after-cutting secondary formations and bogged stages. The survey allowed to reveal records of 3 species listed in the Red Data Book of Russia and 9 species listed in the Red Data Book of Yugra. PMID:29362551

  2. Impact of tree cutting on water-soluble organic compounds in podzolic soils of the European North-East

    NASA Astrophysics Data System (ADS)

    Lapteva, Elena; Bondarenko, Natalia; Shamrikova, Elena; Kubik, Olesya; Punegov, Vasili

    2016-04-01

    Water-soluble organic compounds (WOCs) and their single components, i.e. low-molecular organic acids, alcohols, and carbohydrates, attain a great deal of attention among soil scientists. WOCs are an important component of soil organic matter (SOM) and form as a results of different biological and chemical processes in soils. These processes are mainly responsible for formation and development of soils in aboveground ecosystems. The purpose of the work was identifying qualitative and quantitative composition of low-molecular organic substances which form in podzolic loamy soils against natural reforestation after spruce forest cutting. The studies were conducted on the territory of the European North-East of Russia, in the middle taiga subzone (Komi Republic, Ust-Kulom region). The study materials were soil of undisturbed bilberry spruce forest (Sample Plot 1 (SP1)) and soils of different-aged tree stands where cutting activities took place in winter 2001/2002 (SP2) and 1969/1970 (SP3). Description of soils and vegetation cover on the plots is given in [1]. Low-molecular organic compounds in soil water extracts were identified by the method of gas chromatography mass-spectrometry [2, 3]. Finally, reforestationafterspruceforestcutting was found to be accompanied by different changes in soil chemical composition. In contrast with soils under undisturbed spruce forest, organic soil horizons under different-aged cuts decreased in organic carbon reserves and production of low-molecular organic compounds, changed in soil acidity. Within the soil series of SP1→SP2→SP3, the highest content of WOCs was identified for undisturbed spruce forest (738 mg kg-1 soil). In soils of coniferous-deciduous forests on SP1 and SP3, WOC content was 294 and 441 mg kg-1 soil, correspondingly. Soils at cuts decreased in concentration of any water-soluble low-molecular SOM components as low-molecular acids, alcohols, and carbohydrates. Structure of low-molecular WOCs in the study podzolic

  3. Low to middle tropospheric profiles and biosphere/troposphere fluxes of acidic gases in the summertime Canadian taiga

    NASA Technical Reports Server (NTRS)

    Klemm, O.; Talbot, R. W.; Fitzgerald, D. R.; Klemm, K. I.; Lefer, B. L.

    1994-01-01

    We report features of acidic gases in the troposphere from 9 to 5000 m altitude above ground over the Canadian taiga in the summer of 1990. The measurements were conducted at a 30-m meteorological tower and from the NASA Wallops Electra aircraft as part of the joint U.S.-Canadian Arctic Boundary Layer Expedition (ABLE) 3B Northern Wetland Studies (NOWES). We sampled air for acidic gases using the mist chamber collector coupled with subsequent analysis using ion chromatography. At the tower we collected samples at two heights during a 13-day period, including diurnal studies. Using eddy flux and profile data, we estimated the biosphere/troposphere fluxes of nitric, formic, and acetic acids and sulfur dioxide. For the organic acids, emissions from the taiga in the afternoon hours and deposition during the predawn morning hours were observed. The flux intensities alone were however not high enough to explain the observed changes in mixing ratios. The measured deposition fluxes of nitric acid were high enough to have a significant influence on its mixing ratio in the boundary layer. On three days we measured vertical profiles of nitric, formic, and acetic acids through the lower to midtroposphere. We found that the chemical composition of the troposphere was extremely heterogenous. Pronounced layers of polluted air were readily apparent from our measurements. Local photochemical production and episodic long-range transport of trace components, originating from biomass burning and possibly industrial emissions, appear to have a strong influence on the composition of the troposphere and biosphere/troposphere fluxes of acidic gases at this site.

  4. Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

    NASA Astrophysics Data System (ADS)

    Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

    2015-06-01

    The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

  5. Analyse dendroecologique et dendroclimatique des gisements de bois de lacs de la taiga de l'est de l'Amerique du Nord

    NASA Astrophysics Data System (ADS)

    Gennaretti, Fabio

    The aim of this thesis was to reconstruct ecological processes and climate change in the taiga of Quebec over the last two millennia to understand factors that have strongly influenced the evolution of this majestic region. To obtain the finest spatial and temporal resolution in our analysis, we used annual growth rings of subfossil logs collected in six lakes as paleoecological and paleoclimatic proxies. Deposits of subfossil logs determine the structure of lake littoral ecosystems and support their food webs. Moreover, they may represent long-term carbon sinks. In the first chapter of the thesis, we described present-day stocks of subfossil logs in the selected littoral zones and established log residence time in the lakes by tree-ring or radio carbon dating. Dating also allowed precise identification of each fire that burned the riparian forests during the last millennium. This chapter showed that interactions between terrestrial and aquatic ecosystems in the taiga are strongly influenced by wildfires whose effects can persist for centuries because of strong postfire reductions of log recruitments in lakes. At a local scale, the amount of logs and carbon preserved in littoral stocks depends on the fire history of the last millennium that is specific to each site. At a regional scale, wildfires limit significantly the amount of carbon sequestered in littoral stocks of logs. These stocks represent a negligible fraction of the total taiga carbon storage despite the abundance of lakes and the long residence time of littoral logs (up to five millennia for buried logs). In the second chapter, we combined a detailed inventory of the present-day riparian forest situated along the shoreline of two lakes with the tree-ring dating of the subfossil logs accumulated in the littoral zones facing these shores. Our objective was to determine whether changes in current riparian forest structure and composition within a given site could be attributed to different fire histories

  6. Effect of aluminum, zinc, copper, and lead on the acid-base properties of water extracts from soils

    NASA Astrophysics Data System (ADS)

    Motuzova, G. V.; Makarychev, I. P.; Petrov, M. I.

    2013-01-01

    The potentiometric titration of water extracts from the upper horizons of taiga-zone soils by salt solutions of heavy metals (Pb, Cu, and Zn) showed that their addition is an additional source of the extract acidity because of the involvement of the metal ions in complexation with water-soluble organic substances (WSOSs). At the addition of 0.01 M water solutions of Al(NO3)3 to water extracts from soils, Al3+ ions are also involved in complexes with WSOSs, which is accompanied by stronger acidification of the extracts from the upper horizon of soddy soils (with a near-neutral reaction) than from the litter of bog-podzolic soil (with a strongly acid reaction). The effect of the Al3+ hydrolysis on the acidity of the extracts is insignificantly low in both cases. A quantitative relationship was revealed between the release of protons and the ratio of free Cu2+ ions to those complexed with WSOSs at the titration of water extracts from soils by a solution of copper salt.

  7. Climatically induced interannual variability in aboveground production in forest-tundra and northern taiga of central Siberia.

    PubMed

    Knorre, Anastasia A; Kirdyanov, Alexander V; Vaganov, Eugene A

    2006-02-01

    To investigate the variability of primary production of boreal forest ecosystems under the current climatic changes, we compared the dynamics of annual increments and productivity of the main components of plant community (trees, shrubs, mosses) at three sites in the north of Siberia (Russia). Annual radial growth of trees and shrubs was mostly defined by summer temperature regime (positive correlation), but climatic response of woody plants was species specific and depends on local conditions. Dynamics of annual increments of mosses were opposite to tree growth. The difference in climatic response of the different vegetation components of the forest ecosystems indicates that these components seem to be adapted to use climatic conditions during the short and severe northern summer, and decreasing in annual production of one component is usually combined with the increase of other component productivity. Average productivity in the northern forest ecosystems varies from 0.05 to 0.14 t ha(-1) year(-1) for trees, from 0.05 to 0.18 t ha(-1) year(-1) for shrubs and from 0.54 to 0.66 t ha(-1) year(-1) for mosses. Higher values of tree productivity combined with lower annual moss productivity were found in sites in northern taiga in comparison with forest-tundra. Different tendencies in the productivity of the dominant species from each vegetation level (trees, shrubs, mosses) were indicated for the last 10 years studied (1990-1999): while productivity of mosses is increasing, productivity of trees is decreasing, but there is no obvious trend in the productivity of shrubs. Our results show that in the long term, the main contribution to changes in annual biomass productivity in forest-tundra and northern taiga ecosystems under the predicted climatic changes will be determined by living ground cover.

  8. Rheological Properties of Automorphic and Semihydromorphic Cryometamorphic Northern Taiga Soils in Northeastern European Russia (Komi Republic)

    NASA Astrophysics Data System (ADS)

    Kholopov, Yu. V.; Khaidapova, D. D.; Lapteva, E. M.

    2018-04-01

    Soil pastes at the water content corresponding to the maximum swelling of samples from different genetic horizons of cryometamorphic soils―surface-gleyic iron-illuvial svetlozem (Folic Albic Stagnosol) and peaty and peat humus-impregnated gleyic svetlozems (Histic Gleyic Stagnosols)―have been studied with an MCR-302 modular rheometer (Anton Paar, Austria). It has been found that the strongest interparticle bonds are formed in the horizons of cryometamorphic soils characterized by high contents of humic substances and organomineral Al-Fe-humus compounds. These are horizons of podzol microprofile (Eg and BHF) in iron-illuvial svetlozem and a humus-impregnated horizon (ELhi,g) in peaty and peat svetlozems. Organomineral Al-Fe-humus compounds, as well as the seasonal freezing of soils, determine the elastic-brittle character of interparticle interactions. The contents of clay fractions, exchangeable bases, and organic and organomineral substances impart viscoelastic properties to these contacts. An enhancement of elastic-brittle properties of soil is observed under the impact of gleying and freezing. The threefold decrease of the structural interaction parameter (∫ Z) when going from automorphic to semihydromorphic conditions indicates a decrease in the resistance of peaty and peat svetlozems to mechanical loads under increasing hydromorphism compared to iron-illuvial svetlozems.

  9. [PCR identification of DNA of hosts of the taiga tick nymphs (Ixodes persulcatus: Ixodinae) in St. Petersburg and its suburbs].

    PubMed

    Grigor'eva, L A; Markov, A V

    2011-01-01

    PCR identification of host DNA in unfed females and males of taiga tick Ixodes persulcatus was performed. Amplification of each sample was done using primers species-specific by 12S rDNA mitochondrial gene. Four species of small mammals (Apodemus uralensis, Clethrionomys glareolus, Microtus arvalis, and Sorex araneus) and two passeriform bird species (Fringilla coelebs and Parus major) were analysed. For one third of tick samples, hosts of previous stages were established using this method. In five cases, feeding on more than one host species was detected.

  10. Biologically Active Organic Matter in Soils of European Russia

    NASA Astrophysics Data System (ADS)

    Semenov, V. M.; Kogut, B. M.; Zinyakova, N. B.; Masyutenko, N. P.; Malyukova, L. S.; Lebedeva, T. N.; Tulina, A. S.

    2018-04-01

    Experimental and literature data on the contents and stocks of active organic matter in 200 soil samples from the forest-tundra, southern-taiga, deciduous-forest, forest-steppe, dry-steppe, semidesert, and subtropical zones have been generalized. Natural lands, agrocenoses, treatments of long-term field experiments (bare fallow, unfertilized and fertilized crop rotations, perennial plantations), and different layers of soil profile are presented. Sphagnum peat and humus-peat soil in the tundra and forest-tundra zones are characterized by a very high content of active organic matter (300-600 mg C/100 g). Among the zonal soils, the content of active organic matter increases from the medium (75-150 mg C/100 g) to the high (150-300 mg C/100 g) level when going from soddy-podzolic soil to gray forest and dark-gray forest soils and then to leached chernozem. In the series from typical chernozem to ordinary and southern chernozem and chestnut and brown semidesert soils, a decrease in the content of active organic matter to the low (35-75 mg C/100 g) and very low (<35 mg C/100 g) levels is observed. Acid brown forest soil in the subtropical zone is characterized by a medium supply with active organic matter. Most arable soils are mainly characterized by low or very low contents of active organic matter. In the upper layers of soils, active organic matter makes up 1.2-11.1% of total Corg. The profile distribution of active organic matter in the studied soils coincides with that of Corg: their contents appreciably decrease with depth, except for brown semidesert soil. The stocks of active organic matter vary from 0.4 to 5.4 t/ha in the layer of 0-20 cm and from 1.0 to 12.4/ha in the layer of 0-50 cm of different soil types.

  11. Specific features of the morphology and chemical properties of coarse-textured postagrogenic soils of the southern taiga, Kostroma oblast

    NASA Astrophysics Data System (ADS)

    Telesnina, V. M.; Vaganov, I. E.; Karlsen, A. A.; Ivanova, A. E.; Zhukov, M. A.; Lebedev, S. M.

    2016-01-01

    The properties of loamy sandy postagrogenic soils in the course of their natural overgrowing were studied in the southeastern part of Kostroma oblast. Micromorphological indications of tillage were preserved in these soils at least 35-40 years after the cessation of their agricultural use. In the course of the soil overgrowing with forest vegetation, the bulk density of the upper part of the former plow horizon decreased, the pH and the ash content of the litter horizon somewhat lowered with a simultaneous increase in the acidity of the upper mineral horizon, especially at the beginning of the formation of the tree stand. In 5-7 years after the cessation of tillage, the former plow horizon was differentiated with respect to the organic carbon content. The total pool of organic carbon in the upper 30 cm increased. In the course of the further development, in the postagrogenic soil under the 90to 100-year-old forest, the organic carbon pool in this layer became lower. The soil of the young fallow (5-7 years) was characterized by the higher values of the microbial biomass in the upper mineral horizon in comparison with that in the plowed soil. In general, the microbial biomass in the studied postagrogenic ecosystems (the soils of the fields abandoned in 2005 and 2000 and the soil under the secondary 40-year-old forest) was lower than that in the soil of the subclimax 90to 100-year-old forest. The enzymatic activity of the soils tends to increase during the succession. The restoration of the invertase and, partly, catalase activities to the values typical of the soils under mature forests takes place in about 40 years.

  12. Input and behavior of polycyclic aromatic hydrocarbons in arable, fallow, and forest soils of the taiga zone (Tver oblast)

    NASA Astrophysics Data System (ADS)

    Zhidkin, A. P.; Gennadiev, A. N.; Koshovskii, T. S.

    2017-03-01

    Contents of 11 most prevalent polycyclic aromatic hydrocarbons (PAHs) in snow and soils of arable, fallow, and forest areas significantly remote from impact technogenic sources of polyarenes have been examined in the Torzhok district of Tver oblast. From the analysis of snow samples, the volumes and composition of PAHs coming from the atmosphere onto the areas of different land use have been determined. Light hydrocarbons prevail in PAHs. They make up 65-70% of total PAHs; their share in soils reaches almost 95%. An increase in the content of PAHs is revealed in fallow soils compared to arable and afforested areas. A direct relationship is revealed between the lateral distribution of total PAHs and the content of organic carbon. The distribution of total PAHs is surface-accumulative in forest soils, mainly uniform in arable soils, and deepaccumulative in fallow soils. PAH groups characterized by similar radial distributions and ratios between their reserves in snow and soils are distinguished: (1) fluorene and phenanthrene, (2) biphenyl and naphthalene, (3) benzo(a)anthracene, chrysene, perylene, and benzo[ a]pyrene, and (4) anthracene and benzo[ ghi]pyrene.

  13. The influence of spruce on acidity and nutrient content in soils of Northern Taiga dwarf shrub-green moss spruce forests

    NASA Astrophysics Data System (ADS)

    Orlova, M. A.; Lukina, N. V.; Smirnov, V. E.; Artemkina, N. A.

    2016-11-01

    Presently, among the works considering the influence of forest trees on soil properties, the idea that spruce ( Picea abies) promotes the acidification of soils predominates. The aim of this work is to assess the effects of spruce trees of different ages and Kraft classes on the acidity and content of available nutrient compounds in the soils under boreal dwarf shrub-green moss spruce forests by the example of forest soils in the Kola Peninsula. The soils are typical iron-illuvial podzols (Albic Rustic Podzols (Arenic)). Three probable ways of developing soils under spruce forests with the moss-dwarf shrub ground cover are considered. The soils under windfall-soil complexes of flat mesodepressions present the initial status. The acidity of organic soil horizons from the initial stage of mesodepression overgrowth to the formation of adult trees changed nonlinearly: the soil acidity reached its maximum under the 30-40-year-old trees and decreased under the trees older than 100 years. The contents of nitrogen and available nutrients increased. The acidity of the mineral soil horizons under the trees at the ages of 110-135 and 190-220 years was comparable, but higher than that under the 30-40-year-old trees. The differences in the strength and trends of the trees' effect on the soils are explained by the age of spruce trees and their belonging to different Kraft classes.

  14. Complexation humic substances of soils with metal ions as the main way migration of matals from soil to water

    NASA Astrophysics Data System (ADS)

    Dinu, Marina

    2013-04-01

    northern taiga soils; (2) similar amounts of oxygen bearing fragments, hydrocarbon constituents, and nitrogen bearing components in the mixed forest zones; (3) occurrence of aromatic and aliphatic hydrocarbons in HM of steppe soils. The HM functional characteristics influence substantially the stability constants of complexes with metal ions and complex stoichiometry: Fe(III)>Cu(II)>Pb(II)>Al(III)>Co(II)>Ni(II)>Cd(II)>Zn(II)>Cr(III)>Mg(II)>Sr(II)>Ca(II)>Mn(II) - northern taiga soils; Cu(II)>Fe(III)>Al(III)>Ni(II)>Zn(II)>Pb(II)>Co(II)>Cd(II)>Sr(II)>Mn(II)>Cr(III)>Ca(II)>Mg(II) - mixed forest zones; Fe(III)>Cu(II)>Al(III)>Pb(II)>Ni(II)>Zn(II)>Co(II)>Ca(II)>Cd(II)>Sr(II)>Mg(II)>Cr(III)>Mn(II) - steppe soils. 1. T.I. Moiseenko, L.P. Kudryavtseva, and N.A. Gashkina, Scattered Element in Surface Land Waters: Technophility, Bioaccumulation, and Ecotoxicology (Nauka, Moscow, 2006) 2. G. M. Varshal, Ext. Abstr. Doct. Dis. Chem. (Inst. Geokh. Analit. Khim. RAN, Moscow, 1994).. 4. D.S. Orlov, Humic Acids (MGU, Moscow, 1986) 5. D.V. Kovalevsky, Ext. Abstr. Cand. Dis. Chem. (MGU, Moscow, 1998). 6. I.A. Linnik and B. I. Nabivanets, Metal Migration Forms in Surface Fresh Waters (Gidrometizdat, Leningrad, 1985) 7. Hartley, F., Burgess, C., and Alcoc, R., Solution Equilibria (Ellis Horwood, Chichester (UK), 1980). 8. Yu. Yu. Lur'e, Reference Book of Physicochemical Values (Nauka, Moscow, 2000)

  15. Short-term standard litter decomposition across three different ecosystems in middle taiga zone of West Siberia

    NASA Astrophysics Data System (ADS)

    Filippova, Nina V.; Glagolev, Mikhail V.

    2018-03-01

    The method of standard litter (tea) decomposition was implemented to compare decomposition rate constants (k) between different peatland ecosystems and coniferous forests in the middle taiga zone of West Siberia (near Khanty-Mansiysk). The standard protocol of TeaComposition initiative was used to make the data usable for comparisons among different sites and zonobiomes worldwide. This article sums up the results of short-term decomposition (3 months) on the local scale. The values of decomposition rate constants differed significantly between three ecosystem types: it was higher in forest compared to bogs, and treed bogs had lower decomposition constant compared to Sphagnum lawns. In general, the decomposition rate constants were close to ones reported earlier for similar climatic conditions and habitats.

  16. (abstract) Monitoring Seasonal Change in Taiga Forests Using ERS-1 SAR Data

    NASA Technical Reports Server (NTRS)

    Way, JoBea; Rignot, Eric; McDonald, Kyle; Viereck, Leslie; Williams, Cynthia; Adams, Phyllis; Payne, Cheryl; Wood, William

    1993-01-01

    Sensitivity of radar backscatter to the dielectric and geometric character of forested regions suggests significant changes in backscatter are expected with season due to freezing temperatures, snow, wind, leaf fall, and drought. The first European Remote Sensing Satellite, ERS-1, offers a unique opportunity to monitor a complete seasonal cycle for the Alaskan taiga forest ecosystem with synthetic aperture radar. During the 3-day repeat Commissioning Phase of ERS-1, from August 1991to December 1991, ERS-1 SAR data were collected in the region of Manley Hot Springs, Alaska, along the Tanana River, west of Fairbanks. In parallel with the SAR data collection, meteorological data from three weather stations positioned in three forest stands were collected continuously along with in situ measurements of the dielectric and moisture properties of the canopy and of ground cover which were collected during each overflight. The in situ data were collected in floodplain forest stands dominated by balsam poplar, white spruce, and black spruce. These results from the Commissioning Phase as well as preliminary results from the 35-day Repeat Phase will be presented.

  17. Microbiological transformation of carbon and nitrogen compounds in forest soils of Central Evenkia

    NASA Astrophysics Data System (ADS)

    Sorokin, N. D.; Aleksandrov, D. E.; Grodnitskaya, I. D.; Evgrafova, S. Yu.

    2017-04-01

    It has been found that the total productivity of bacteria and micromycetes in the 0- to 50-cm layer of homogeneous cryozems (Cryosols) on slopes of northern and southern exposures varies from 1.2 to 1.4 t/ha, respectively, and the calculated content of microbial carbon varies in the range 0.7-0.9 t/ha. The respiratory activity of the upper soil layer is 2.5-2.6 μg C-CO2/(g h); the potential methane formation capacity reaches 0.13 nmol CH4/(m2 day) for soils on slopes of northern exposure and 0.16 nmol CH4/(m2 day) for slopes of southern exposure. Accumulation of sorbed ammonium is recorded in the range 15-17 mg NH4/100 g soil in summer. The increase of temperature in the upper horizons of soils on slopes of southern exposure by 5°C compared to the northern slopes results in only an insignificant increase in the emission of CO2 and CH4. The accumulation of sorbed ammonium and nitrate nitrogen in homogeneous cryozems during the vegetation period is comparable to that in gray forest soils of the southern taiga subzone of the Middle Siberia.

  18. Soil factors of ecosystems' disturbance risk reduction under the impact of rocket fuel

    NASA Astrophysics Data System (ADS)

    Krechetov, Pavel; Koroleva, Tatyana; Sharapova, Anna; Chernitsova, Olga

    2016-04-01

    Environmental impacts occur at all stages of space rocket launch. One of the most dangerous consequences of a missile launch is pollution by components of rocket fuels ((unsymmetrical dimethylhydrazine (UDMH)). The areas subjected to falls of the used stages of carrier rockets launched from the Baikonur cosmodrome occupy thousands of square kilometers of different natural landscapes: from dry steppes of Kazakhstan to the taiga of West Siberia and mountains of the Altai-Sayany region. The study aims at assessing the environmental risk of adverse effects of rocket fuel on the soil. Experimental studies have been performed on soil and rock samples with specified parameters of the material composition. The effect of organic matter, acid-base properties, particle size distribution, and mineralogy on the decrease in the concentration of UDMH in equilibrium solutions has been studied. It has been found that the soil factors are arranged in the following series according to the effect on UDMH mobility: acid-base properties > organic matter content >clay fraction mineralogy > particle size distribution. The estimation of the rate of self-purification of contaminated soil is carried out. Experimental study of the behavior of UDMH in soil allowed to define a model for calculating critical loads of UDMH in terrestrial ecosystems.

  19. Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with 137Cs, 226Ra, and 238U

    NASA Astrophysics Data System (ADS)

    Chevychelov, A. P.; Sobakin, P. I.

    2017-12-01

    The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El'kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.

  20. Key Edaphic Properties Largely Explain Temporal and Geographic Variation in Soil Microbial Communities across Four Biomes.

    PubMed

    Docherty, Kathryn M; Borton, Hannah M; Espinosa, Noelle; Gebhardt, Martha; Gil-Loaiza, Juliana; Gutknecht, Jessica L M; Maes, Patrick W; Mott, Brendon M; Parnell, John Jacob; Purdy, Gayle; Rodrigues, Pedro A P; Stanish, Lee F; Walser, Olivia N; Gallery, Rachel E

    2015-01-01

    Soil microbial communities play a critical role in nutrient transformation and storage in all ecosystems. Quantifying the seasonal and long-term temporal extent of genetic and functional variation of soil microorganisms in response to biotic and abiotic changes within and across ecosystems will inform our understanding of the effect of climate change on these processes. We examined spatial and seasonal variation in microbial communities based on 16S rRNA gene sequencing and phospholipid fatty acid (PLFA) composition across four biomes: a tropical broadleaf forest (Hawaii), taiga (Alaska), semiarid grassland-shrubland (Utah), and a subtropical coniferous forest (Florida). In this study, we used a team-based instructional approach leveraging the iPlant Collaborative to examine publicly available National Ecological Observatory Network (NEON) 16S gene and PLFA measurements that quantify microbial diversity, composition, and growth. Both profiling techniques revealed that microbial communities grouped strongly by ecosystem and were predominately influenced by three edaphic factors: pH, soil water content, and cation exchange capacity. Temporal variability of microbial communities differed by profiling technique; 16S-based community measurements showed significant temporal variability only in the subtropical coniferous forest communities, specifically through changes within subgroups of Acidobacteria. Conversely, PLFA-based community measurements showed seasonal shifts in taiga and tropical broadleaf forest systems. These differences may be due to the premise that 16S-based measurements are predominantly influenced by large shifts in the abiotic soil environment, while PLFA-based analyses reflect the metabolically active fraction of the microbial community, which is more sensitive to local disturbances and biotic interactions. To address the technical issue of the response of soil microbial communities to sample storage temperature, we compared 16S-based community

  1. Key Edaphic Properties Largely Explain Temporal and Geographic Variation in Soil Microbial Communities across Four Biomes

    PubMed Central

    Borton, Hannah M.; Espinosa, Noelle; Gebhardt, Martha; Gil-Loaiza, Juliana; Gutknecht, Jessica L. M.; Maes, Patrick W.; Mott, Brendon M.; Parnell, John Jacob; Purdy, Gayle; Rodrigues, Pedro A. P.; Stanish, Lee F.; Walser, Olivia N.

    2015-01-01

    Soil microbial communities play a critical role in nutrient transformation and storage in all ecosystems. Quantifying the seasonal and long-term temporal extent of genetic and functional variation of soil microorganisms in response to biotic and abiotic changes within and across ecosystems will inform our understanding of the effect of climate change on these processes. We examined spatial and seasonal variation in microbial communities based on 16S rRNA gene sequencing and phospholipid fatty acid (PLFA) composition across four biomes: a tropical broadleaf forest (Hawaii), taiga (Alaska), semiarid grassland-shrubland (Utah), and a subtropical coniferous forest (Florida). In this study, we used a team-based instructional approach leveraging the iPlant Collaborative to examine publicly available National Ecological Observatory Network (NEON) 16S gene and PLFA measurements that quantify microbial diversity, composition, and growth. Both profiling techniques revealed that microbial communities grouped strongly by ecosystem and were predominately influenced by three edaphic factors: pH, soil water content, and cation exchange capacity. Temporal variability of microbial communities differed by profiling technique; 16S-based community measurements showed significant temporal variability only in the subtropical coniferous forest communities, specifically through changes within subgroups of Acidobacteria. Conversely, PLFA-based community measurements showed seasonal shifts in taiga and tropical broadleaf forest systems. These differences may be due to the premise that 16S-based measurements are predominantly influenced by large shifts in the abiotic soil environment, while PLFA-based analyses reflect the metabolically active fraction of the microbial community, which is more sensitive to local disturbances and biotic interactions. To address the technical issue of the response of soil microbial communities to sample storage temperature, we compared 16S-based community

  2. Annual soil CO_{2} production in Moscow Botanical Garden (Russia).

    NASA Astrophysics Data System (ADS)

    Udovenko, Maria; Goncharova, Olga; Matyshak, Georgy

    2017-04-01

    Soil respiration is an essential component of the carbon cycle, determining 25-40 % of carbon dioxide in the atmosphere. Urban soils are subject to significant anthropogenic influences. Anthropogenic impact affects both the plants and the soil microbiota. So, soil CO2 efflux and soil profile CO2 concentration probably differ in urban and natural soils. Influence of abiotic factors on soil carbon dioxide production is explored insufficiently. The research of their impact on soil carbon dioxide production is necessary to predict soil response to anthropogenic climate change. The aim of this study was estimation of annual soil CO2 production and the impact of climatic factors on it. The research took place in Moscow State University Botanical Garden Arboretum (southern taiga). Investigations were carried out at two sites: the areas planted with Picea obovata and Carpinus betulus. The study was conducted with 1-2 weeks intervals between November 2014 and December 2015. Emission measurement were carried out by closed chamber technique, profile concentration were measured by soil air sampling tubes method. Annual carbon dioxide soil surface efflux of soil planted with Picea obovata was 1370 gCO2/(m2 * year), soil planted with Carpinus betulus - 1590 gCO2/(m2 * year). Soil CO2 concentration increased with depth in average of 3300 to 12000 ppm (at 80 cm depth). Maximum concentration values are confined to the end of vegetation period (high biological activity) and to beginning of spring (spring ice cover of soil prevents CO2 emission). Soil CO2 efflux depends on soil temperature at 10 cm depth (R = 0.89; p <0.05), in a less degree it correlate with soil surface temperature and with soil temperature at 20 cm depth (r=0.88; p<0.05). Soil moisture has a little effect on CO2 efflux in the annual cycle (r=-0.16; p<0.05). However in vegetation period efflux of carbon dioxide largely depends on soil moisture, due to the fact, that soil moisture is limiting factor for soil

  3. High-resolution mapping and spatial variability of soil organic carbon storage of permafrost-affected soils

    NASA Astrophysics Data System (ADS)

    Siewert, Matthias; Hugelius, Gustaf

    2017-04-01

    Permafrost-affected soils store large amounts of soil organic carbon (SOC). Mapping of this SOC provides a first order spatial input variable for research that relates carbon stored in permafrost regions to carbon cycle dynamics. High-resolution satellite imagery is becoming increasingly available even in circum-polar regions. The presented research highlights findings of high-resolution mapping efforts of SOC from five study areas in the northern circum-polar permafrost region. These study areas are located in Siberia (Kytalyk, Spasskaya Pad /Neleger, Lena delta), Northern Sweden (Abisko) and Northwestern Canada (Herschel Island). Our high spatial resolution analyses show how geomorphology has a strong influence on the distribution of SOC. This is organized at different spatial scales. Periglacial landforms and processes dictate local scale SOC distribution due to patterned ground. Such landforms are non-sorted circles and ice-wedge polygons of different age and scale. Palsas and peat plateaus are formed and can cover larger areas in Sub-Arctic environments. Study areas that have not been affected by Pleistocene glaciation feature ice-rich Yedoma sediments that dominate the local relief through thermokarst formation and create landscape scale macro environments that dictate the distribution of SOC. A general trend indicates higher SOC storage in Arctic tundra soils compared to forested Boreal or Sub-Arctic taiga soils. Yet, due to the shallower active layer depth in the Arctic, much of the SOC may be permanently frozen and thus not be available to ecosystem processes. Significantly more SOC is stored in soils compared to vegetation, indicating that vegetation growth and incorporation of the carbon into the plant phytomass alone will not be able to offset SOC released from permafrost. This contribution also addresses advances in thematic mapping methods and digital soil mapping of SOC in permafrost terrain. In particular machine-learning methods, such as support

  4. Post fire organic matter biodegradation in permafrost soils: Case study after experimental heating of mineral horizons.

    PubMed

    Masyagina, O V; Tokareva, I V; Prokushkin, A S

    2016-12-15

    Periodical ground fires of high frequency in permafrost forest ecosystems of Siberia (Russian Federation) are essential factors determining quantitative and qualitative parameters of permafrost soil organic matter. Specific changes in physical and chemical parameters and microbial activity of permafrost soil mineral horizons of northern taiga larch stands were revealed after heating at high temperatures (150-500°C) used for imitation of different burn intensities. Burning at 150-200°C resulted in decreasing of soil pH, whilst heating at 300-500°C caused increase of pH compare to unheated soils. Water-soluble organic carbon concentration in permafrost soils heated at 150-200°C was much higher than that of unheated soils. All these changes determined soil microbial activity in heated soils. In particular, in soils heated at 300-500°C there was momentary stimulating effect on substrate-induced respiration registered and on basal respiration values in soils burned at 150°C and 300-400°C. Four-month laboratory incubation of permafrost soils heated at different temperatures showed stimulation of microbial activity in first several days after inoculation due to high substrate availability after heating. Then soon after that soil microbial community started to be depleted on substrate because of decreasing water-soluble organic carbon, C and N content and it continued to the end of incubation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Run-off regime of the small rivers in mountain landscapes (on an example of the mountain "Mongun-taiga

    NASA Astrophysics Data System (ADS)

    Pryahina, G.; Zelepukina, E.; Guzel, N.

    2012-04-01

    Hydrological characteristics calculations of the small mountain rivers in the basins with glaciers frequently cause complexity in connection with absence of standard hydrological supervision within remote mountain territories. The unique way of the actual information reception on a water mode of such rivers is field work. The rivers of the mountain Mongun-taiga located on a joint of Altai and Sayan mountains became hydrological researches objects of Russian geographical society complex expeditions in 2010-2011. The Mongun-taiga cluster of international biosphere reserve "Ubsunurskaya hollow" causes heightened interest of researchers — geographers for many years. The original landscape map in scale 1:100000 has been made, hydrological supervision on the rivers East Mugur and ugur, belonging inland basin of Internal Asia are lead. Supervision over the river drain East Mugur runoff were spent in profile of glacier tongue (the freezing area - 22 % (3.2 km2) from the reception basin) and in the closing alignment of the river located on distance of 3,4 km below tongue of glacier. During researches following results have been received. During the ablation period diurnal fluctuations with a strongly shown maximum and minimum of water discharges are typically for the small rivers with considerable share of a glacial food. The run-off maximum from the glacier takes place from 2 to 7 p.m., the run-off minimum is observed early in the morning. High speed of thawed snow running-off from glacier tongue and rather small volume of dynamic stocks water on an ice surface lead to growth of water discharge. In the bottom profile the time of maximum and minimum of water discharge is displaced on the average 2 hours, it depends of the water travel time. Maximum glacial run-off discharge (1.12 m3/s) in the upper profile was registered on July 16 (it was not rain). Volumes of daily runoff in the upper and bottom profiles were 60700-67600 m3 that day. The run-off from nonglacial part of

  6. Simulation of the hybrid Tunka Advanced International Gamma-ray and Cosmic ray Astrophysics (TAIGA)

    NASA Astrophysics Data System (ADS)

    Kunnas, M.; Astapov, I.; Barbashina, N.; Beregnev, S.; Bogdanov, A.; Bogorodskii, D.; Boreyko, V.; Brückner, M.; Budnev, N.; Chiavassa, A.; Chvalaev, O.; Dyachok, A.; Epimakhov, S.; Eremin, T.; Gafarov, A.; Gorbunov, N.; Grebenyuk, V.; Gress, O.; Gress, T.; Grinyuk, A.; Grishin, O.; Horns, D.; Ivanova, A.; Karpov, N.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kirichkov, N.; Kiryuhin, S.; Kokoulin, R.; Kompaniets, K.; Konstantinov, E.; Korobchenko, A.; Korosteleva, E.; Kozhin, V.; Kuzmichev, L.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Perevalov, A.; Petrukhin, A.; Platonov, V.; Poleschuk, V.; Popescu, M.; Popova, E.; Porelli, A.; Porokhovoy, S.; Prosin, V.; Ptuskin, V.; Romanov, V.; Rubtsov, G. I.; Müger; Rybov, E.; Samoliga, V.; Satunin, P.; Saunkin, A.; Savinov, V.; Semeney, Yu; Shaibonov (junior, B.; Silaev, A.; Silaev (junior, A.; Skurikhin, A.; Slunecka, M.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Veslopopov, A.; Veslopopova, E.; Voronov, D.; Wischnewski, R.; Yashin, I.; Yurin, K.; Zagorodnikov, A.; Zirakashvili, V.; Zurbanov, V.

    2015-08-01

    Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion quality and gamma-hadron separation power. However, sensitive observations at and above 100 TeV require very large effective areas (10 km2 and more), which is difficult and expensive to achieve. The alternative to IACTs are shower front sampling arrays (non-imaging technique or timing-arrays) with a large area and a wide field of view. Such experiments provide good core position, energy and angular resolution, but only poor gamma-hadron separation. Combining both experimental approaches, using the strengths of both techniques, could optimize the sensitivity to the highest energies. The TAIGA project plans to combine the non-imaging HiSCORE [8] array with small (∼10m2) imaging telescopes. This paper covers simulation results of this hybrid approach.

  7. Soils of northern spurs of the Cherskii Ridge in the area of the northern pole of cold: Morphology, properties, and classification

    NASA Astrophysics Data System (ADS)

    Okoneshnikova, M. V.; Desyatkin, R. V.

    2017-08-01

    The soils in the area of the northern pole of cold located on the interfluve between the Yana and Adycha rivers within the spurs of Kisilyakh Ridge included in the mountain system of Cherskii Ridge have been studied for the first time. The profile-genetic approach has been applied to describe the soils and determine their classification position. It is found that the major soil types in this region are the soils of the postlithogenic trunk belonging to the orders of lithozems (Cryic Leptosols), gley soils (Gleyic Skeletic Cryosols), and Al-Fe-humus soils (Spodic Skeletic Cryosols). The ecological ranges of altitudinal zones— the taiga zone with various types of lithozems below 630-700 m a.s.l. and the tundra zone with combinations of gley and nongley cryogenic soils above these heights—have been established. The development of gley or nongley soils is specified by the local orogenic and lithological conditions and slope aspect, which, in turn, control the degree of drainage and the presence and character of permafrost. In the profile of mountainous gley soils (gleyzems) with shallow ice-rich permafrost, cryogenic processes and features typical of the analogues of these soils on plains—cryogenic cracking, cryoturbation, solifluction, thixotropy, oxiaquic features above permafrost, saturation of the soil profile with mobile humus, etc.—are typical.

  8. Influence of forest stands on soil and ecosystem carbon stocks in the conditions of the European part of Russia

    NASA Astrophysics Data System (ADS)

    Kaganov, Vladimir

    2016-04-01

    Forest stands are one of the most important components of ecosystems, both in Russia and around the world and at the same time forest vegetation is able to provide environment-modifying effect on the occupied landscape and, in particular, on the soil cover. Currently, due to the large interest in the carbon cycle, there is a question about the influence of forest vegetation on carbon stocks in ecosystems and in particular in the soil cover. To perform the study we selected 9 objects located in the European part of Russia from the area of the southern taiga to the semi-desert zone: Novgorod region, Kostroma region, Moscow region (2 objects), Penza region, Voronezh region, Volgograd region (2 objects) and Astrakhan region. For studying the influence of forest vegetation on the soil`s carbon, we organized the following experiment scheme: in each of the objects two key sites were selected, so that they originally were in the same soil conditions and the difference between them was only in a course development of vegetation - forest or grass. One part of the experimental sites, presenting forest vegetation, were the restored forests on abandoned lands with the age of 70-200 years. The second part of the experimental sites were artificial forest plantations aged from 60 to 112 years planted on the originally treeless forest-steppe or steppe landscapes. Perennial hayfields, perennial abandoned agricultural landscapes and virgin steppe areas were used as reference sites with grass vegetation. For each forest site we estimated the major carbon pools: phytomass, mortmass (dead wood, dry grass), debris, litter and soil. All data were recalculated using the conversion factors in carbon stocks in t C ha-1. We collected soil samples every 10 cm until the depth of 50 cm, and then at 50-75 and 75-100 cm soil layers. Bulk density and total organic carbon were determined by CHN analyzer. As a result, the soil`s carbon was also calculated into t C ha-1. We found out that the total

  9. Individual organic compounds in water extracts from podzolic soils of the Komi Republic

    NASA Astrophysics Data System (ADS)

    Shamrikova, E. V.; Punegov, V. V.; Gruzdev, I. V.; Vanchikova, E. V.; Vetoshkina, A. A.

    2012-10-01

    The contents of organic compounds in water extracts from organic horizons of loamy soils with different water contents from the medium taiga zone of the Komi Republic were determined by gas-liquid chromatography and chromatography-mass spectrometry. The mass concentration of organic carbon in the extracts was in the range of 290-330 mg/dm3; the mass fraction of the carbon from the identified compounds was 0.5-1.9%. Hydrocarbons made up about 60% of the total identified compounds; acids and their derivatives composed less than 40%. Most of the acids (40-70%) were aliphatic hydroxy acids. The tendencies in the formation of different classes of organic compounds were revealed depending on the degree of the soil hydromorphism. The acid properties of the water-soluble compounds were studied by pK spectroscopy. Five groups of compounds containing acid groups with similar pKa values were revealed. The compounds containing groups with pKa < 4.0 were predominant. The increase in the surface wetting favored the formation of compounds with pKa 3.2-4.0 and 7.4-8.4.

  10. Calibration and Validation of Landsat Tree Cover in the Taiga-Tundra Ecotone

    NASA Technical Reports Server (NTRS)

    Montesano, Paul Mannix; Neigh, Christopher S. R.; Sexton, Joseph; Feng, Min; Channan, Saurabh; Ranson, Kenneth J.; Townshend, John R.

    2016-01-01

    Monitoring current forest characteristics in the taiga-tundra ecotone (TTE) at multiple scales is critical for understanding its vulnerability to structural changes. A 30 m spatial resolution Landsat-based tree canopy cover map has been calibrated and validated in the TTE with reference tree cover data from airborne LiDAR and high resolution spaceborne images across the full range of boreal forest tree cover. This domain-specific calibration model used estimates of forest height to determine reference forest cover that best matched Landsat estimates. The model removed the systematic under-estimation of tree canopy cover greater than 80% and indicated that Landsat estimates of tree canopy cover more closely matched canopies at least 2 m in height rather than 5 m. The validation improved estimates of uncertainty in tree canopy cover in discontinuous TTE forests for three temporal epochs (2000, 2005, and 2010) by reducing systematic errors, leading to increases in tree canopy cover uncertainty. Average pixel-level uncertainties in tree canopy cover were 29.0%, 27.1% and 31.1% for the 2000, 2005 and 2010 epochs, respectively. Maps from these calibrated data improve the uncertainty associated with Landsat tree canopy cover estimates in the discontinuous forests of the circumpolar TTE.

  11. Soil-geographical and ecological tour in West-Russia: 20 years anniversary

    NASA Astrophysics Data System (ADS)

    Kuzyakov, Yakov

    2013-04-01

    Soil-geographical and agro-ecological tour in Russia celebrated in this summer its 20 years anniversary! More than 800 students, PhD students and researcher from Germany, Switzerland, Austria, Sweden and France participated at the tour since 1993. The majority of the participants were students studying soil science, geoecology, geography, agriculture and ecology. The tour is based on a classical Russian zonal approach: a cross-section of climatic zones starting from south taiga, through deciduous forest, forest steppe, steppe, dry steppe, to semi dessert and transition to the desert zone. In each zone the specifics of climate, vegetation, nutrient cycling, and of course soil genesis as well as soil use by forestry and agriculture are described. Half of the soil group units of WRB classification (2006) are presented on about 35 soil profile pits and are described with focus on pedogenic processes and soil forming factors. The following soil groups are described in details by horizons according to WRB soil classification (2006): Arenosols, Podzols, Albeluvisols Histosols, Gleysols, Luvisols, Phaeozems, Chernozems, Kastanozems, Calcisols, Vertisols, Leptosols, Fluvisols, Solonetzes, Solonchaks. In addition to natural conditions, large-scale experiments designing agricultural landscapes (stone steppe), biosphere reserves and conservation areas (Tula-Schneisen, Divnogor'je, Baskunchak), as well as collective agricultural farms (previously kolkhoz) are visited to evaluate the anthropogenic effects on ecosystems and especially on soils. The 2.5 weeks bus journey through many villages and small towns, visits of museums and historical monuments, introduction in the settlement development of different regions provide a broad presentation of Russian history, traditions, life style, and contemporary state. So, combination of very diverse educational part focused on soil and environmental conditions with anthropogenic impacts and local history as well as recent socioeconomic

  12. [Microorganisms of the order Rickettsiales in taiga tick (Ixodes persulcatus Sch.) from the Pre-Ural region].

    PubMed

    Nefedova, V V; Korenberg, E I; Kovalevskiĭ, Iu V; Gorelova, N B; Vorob'eva, N N

    2008-01-01

    The PCR and sequence analysis revealed DNA Ehrlichia muris, Anaplasma phagocytophilum, and Rickettsia spp. in the I. persulcatus ticks and blood samples from a patients with acute febrile illness occurring after a tick bite, registered in the seasonal peak of the tick activity of one of the highly endemic areas of Russia (Perm region). These data confirmed the validity a diagnosis of HME and HGA, which were made earlier on the basis of the clinical-serologic survey. In 10.0% of the tested taiga ticks were detected DNA of two and more agents in various combinations i.e. E. muris and Rickettsia spp, A. phagocytophilum and Rickettsia spp., and E. muris, A. phagocytophilum and Rickettsia spp. DNA of a R. helvetica was detected in I. persulcatus tick and blood tick-bitten patient with febrile episodes. Probably that R. helvetica can be etiological agent in some part of cases with the serologically unconfirmed diagnoses of acute feverish diseases developing after tick bite.

  13. Transformation of ecofunctional parameters of soil microbial cenoses in clearings for power transmission lines in Central Siberia

    NASA Astrophysics Data System (ADS)

    Bogorodskaya, A. V.; Ponomareva, T. V.; Efimov, D. Yu.; Shishikin, A. S.

    2017-06-01

    Changes in soil microbial processes and phytocenotic parameters were studied in clearings made for power transmission lines in the subtaiga and southern taiga of Central Siberia. In these clearings, secondary meadow communities play the main environmental role. The substitution of meadow vegetation for forest vegetation, the increase in the phytomass by 40-120%, and the transformation of the hydrothermic regime in the clearings led to the intensification of the humus-accumulative process, growth of the humus content, reduction in acidity and oligotrophy of the upper horizons in the gray soils of the meadow communities, and more active microbial mineralization of organic matter. In the humus horizon of the soils under meadows, the microbial biomass (Cmicr) increased by 20-90%, and the intensity of basal respiration became higher by 60-90%. The values of the microbial metabolic quotient were also higher in these soils than in the soils under the native forests. In the 0- to 50-cm layer of the gray soils under the meadows, the total Cmicr reserves were 35-45% greater and amounted to 230-320 g/m3; the total microbial production of CO2 was 1.5-2 times higher than that in the soil of the adjacent forest and reached 770-840 mg CO2-C/m3 h. The predominance of mineralization processes in the soils under meadows in the clearings reflected changes in edaphic and trophic conditions of the soils and testified to an active inclusion of the herb falloff into the biological cycle.

  14. [Conjugated variability of spontaneous activity and behavioral response to olfactory stimuli in the taiga tick (Ixodes persulcatus)].

    PubMed

    Romashchenko, A V; Shnaĭder, E P; Petrovskiĭ, D V; Moshkin, M P

    2013-01-01

    According to -the automatic tracing of the movement of ticks in a Petri dish, motivational variability of the spontaneous activity and behavioral response of the taiga tick to olfactory stimuli was analyzed. In the studied sample, two groups of ticks that differ in the movement trajectory in the absence of stimulus were isolated, including ticks that mainly moved on the edge of the dish at maximum accessible height (group 1) and ticks that mainly moved at the bottom and wall of the dish (group 2). It was registered that ticks of group 1 (as opposed to ticks of group 2) demonstrated a pronounced behavioral response to olfactory stimuli (human synthetic pheromones and ammonia) and negative geotaxis. It was established that belonging to these groups depended On the time of day when the testing was performed and did not depend on the physiological age and infectious status.

  15. Permafrost thaw and wildfire: Equally important drivers of boreal tree cover changes in the Taiga Plains, Canada

    NASA Astrophysics Data System (ADS)

    Helbig, M.; Pappas, C.; Sonnentag, O.

    2016-02-01

    Boreal forests cover vast areas of the permafrost zones of North America, and changes in their composition and structure can lead to pronounced impacts on the regional and global climate. We partition the variation in regional boreal tree cover changes between 2000 and 2014 across the Taiga Plains, Canada, into its main causes: permafrost thaw, wildfire disturbance, and postfire regrowth. Moderate Resolution Imaging Spectroradiometer Percent Tree Cover (PTC) data are used in combination with maps of historic fires, and permafrost and drainage characteristics. We find that permafrost thaw is equally important as fire history to explain PTC changes. At the southern margin of the permafrost zone, PTC loss due to permafrost thaw outweighs PTC gain from postfire regrowth. These findings emphasize the importance of permafrost thaw in controlling regional boreal forest changes over the last decade, which may become more pronounced with rising air temperatures and accelerated permafrost thaw.

  16. Assessment of Soil Water Composition in the Northern Taiga Coniferous Forests of Background Territories in the Industrially Developed Region

    NASA Astrophysics Data System (ADS)

    Lukina, N. V.; Ershov, V. V.; Gorbacheva, T. T.; Orlova, M. A.; Isaeva, L. G.; Teben'kova, D. N.

    2018-03-01

    The composition of soil water under coniferous forests of Murmansk oblast—an industrially developed region of northern Russia—was investigated. The studied objects were dwarf-shrub-green-moss spruce forests and dwarf-shrub-lichen pine forests on Al-Fe-humus podzols ( Albic Rustic Podzols) that are widespread in the boreal zone. The concentrations and removal of organic carbon performing the most important biogeochemical and pedogenic functions were estimated. The results proved significant intra- and inter-biogeocenotic variability in the composition of atmospheric depositions and soil water. Carbon removal with soil water from organic and mineral horizons within elementary biogeoareas (EBGA) under tree crowns was 2-5 and 2-3 times (in some cases, up to 10 times) greater than that in the intercrown areas, respectively. The lowest critical level of mineral nitrogen (0.2 mg/L) was, as a rule, exceeded in tree EBGAs contrary to intercrown areas. Concentrations of sulfates and heavy metals in water of tree EBGA were 3-5 times greater than those in inter-crown areas. Significant inter-biogeocenotic variations related to differences in the height of trees and tree stand density were found. It is argued that adequate characterization of biochemical cycles and assessment of critical levels of components in soil water of forest ecosystems should be performed with due account for the intra- and inter-biogeocenotic variability.

  17. Temporal variability of methane fluxes in West Siberian taiga bogs and its implications for estimating regional methane emission

    NASA Astrophysics Data System (ADS)

    Sabrekov, Alexander; Ilyasov, Danil; Terentieva, Irina; Glagolev, Mikhail; Maksyutov, Shamil

    2017-04-01

    The West Siberia Lowland (WSL) is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. During 2015-16 summer periods, seasonal measurements of methane emission were made at the field station «Mukhrino» in the WSL middle taiga zone. The study was made at 3 wetland ecosystem types covering 80% of the taiga wetland area: i) waterlogged hollows or depressed areas with water level above the moss surface, ii) oligotrophic hollows or depressed parts of bogs with water level beneath the moss surface, iii) forested bogs with dwarf shrubs-sphagnum vegetation. Seven series of measurements were made by a static chamber method in 2016 and four series - in 2015. In 2015, we observed non-typical weather conditions including early dry spring and short cold rainy summer. Oppositely, weather conditions in 2016 were closer to average long-term with warmer drier summer. Significant difference between these years allowed analyzing the temporal variability and its sources. Average methane flux rates from forested bogs were 0.57 mgCH4/m2/h in 2016 and 0.33 mgCH4/m2/h in 2015. Seasonal dynamic during both years had similar concave downward shape. The highest fluxes were observed in June and were corresponded to the highest WTL, the main limiting factor of emission from forested bogs. The lowest fluxes in July were related to the low WTL combining with the highest temperature of upper methanotrophy layer. Average methane flux rates from oligotrophic hollows were 7.18 mgCH4/m2/h in 2016 and 4.28 mgCH4/m2/h in 2015. Seasonal dynamic of methane emission was indistinct in 2015. On the contrary, in 2016 it had regular seasonal pattern with peak emissions in July, which were four times higher than in 2015. WTL was not the limiting factor for CH4 emission from oligotrophic hollows, because even in the driest ones it was only 10 cm below the surface. Thus, the difference between peak emissions in 2015 and 2016 was mainly related

  18. Methane and carbon dioxide fluxes in the waterlogged forests of south and middle taiga of Western Siberia

    NASA Astrophysics Data System (ADS)

    Glagolev, M. V.; Ilyasov, D. V.; Terentieva, I. E.; Sabrekov, A. F.; Mochenov, S. Yu; Maksutov, S. S.

    2018-03-01

    Field measurements of methane and carbon dioxide flux were carried out using portable static chambers in south (ST) and middle taiga subzones (MT) of Western Siberia (WS) from 16 to 24 August 2015. Two sites were investigated: Bakchar bog in the Tomsk region (in typical ecosystems for this area: oligotrophic bog/forest border and waterlogged forest) and Shapsha in Khanty-Mansiysk region (in waterlogged forest). The highest values of methane fluxes (mgC·m-2·h-1) were obtained in burnt wet birch forest (median 6.96; first quartile 3.12; third quartile 8.95). The lowest values of methane fluxes (among the sites mentioned above) were obtained in seasonally waterlogged forests (median -0.08; first and third quartiles are -0.14 and -0.03 mgC·m-2·h-1 respectively). These data will help to estimate the regional methane flux from the waterlogged and periodically flooded forests and to improve its prediction.

  19. Life cycle of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in the North-West of Russia.

    PubMed

    Grigoryeva, L A; Stanyukovich, M K

    2016-07-01

    The life cycle of Ixodes persulcatus lasts 3 years in the conditions of the Leningrad province (North-West Russia), the development of each phase taking a year. The normal age of the taiga tick is 3 years. The calendar age of larvae and nymphs reaches 11-12 months under favorable abiotic and biotic factors, while the calendar age of adults does not exceed 11 months. At the preimaginal phases of development the ticks that breed in August can feed before or after winter. However, their metamorphosis begins and reaches completion within the same timeframes (from late June to early August) and lasts for about 30-50 (60) days. The survival rate of hungry and engorged larvae and nymphs after wintering is quite high (88.6-100 %). We explain the low activity of larvae and nymphs in late summer and autumn by incomplete development. Morphogenetic diapause of engorged larvae and nymphs interrupts digestion but not metamorphosis which starts only in late June and July after the complete absorption of blood from the gut cavity.

  20. Soil carbon sequestration due to post-Soviet cropland abandonment: estimates from a large-scale soil organic carbon field inventory.

    PubMed

    Wertebach, Tim-Martin; Hölzel, Norbert; Kämpf, Immo; Yurtaev, Andrey; Tupitsin, Sergey; Kiehl, Kathrin; Kamp, Johannes; Kleinebecker, Till

    2017-09-01

    The break-up of the Soviet Union in 1991 triggered cropland abandonment on a continental scale, which in turn led to carbon accumulation on abandoned land across Eurasia. Previous studies have estimated carbon accumulation rates across Russia based on large-scale modelling. Studies that assess carbon sequestration on abandoned land based on robust field sampling are rare. We investigated soil organic carbon (SOC) stocks using a randomized sampling design along a climatic gradient from forest steppe to Sub-Taiga in Western Siberia (Tyumen Province). In total, SOC contents were sampled on 470 plots across different soil and land-use types. The effect of land use on changes in SOC stock was evaluated, and carbon sequestration rates were calculated for different age stages of abandoned cropland. While land-use type had an effect on carbon accumulation in the topsoil (0-5 cm), no independent land-use effects were found for deeper SOC stocks. Topsoil carbon stocks of grasslands and forests were significantly higher than those of soils managed for crops and under abandoned cropland. SOC increased significantly with time since abandonment. The average carbon sequestration rate for soils of abandoned cropland was 0.66 Mg C ha -1  yr -1 (1-20 years old, 0-5 cm soil depth), which is at the lower end of published estimates for Russia and Siberia. There was a tendency towards SOC saturation on abandoned land as sequestration rates were much higher for recently abandoned (1-10 years old, 1.04 Mg C ha -1  yr -1 ) compared to earlier abandoned crop fields (11-20 years old, 0.26 Mg C ha -1  yr -1 ). Our study confirms the global significance of abandoned cropland in Russia for carbon sequestration. Our findings also suggest that robust regional surveys based on a large number of samples advance model-based continent-wide SOC prediction. © 2017 John Wiley & Sons Ltd.

  1. The temperature characteristics of biological active period of the peat soils of Bakchar swamp

    NASA Astrophysics Data System (ADS)

    Kiselev, M. V.; Dyukarev, E. A.; Voropay, N. N.

    2018-01-01

    The results of the study of the peculiarities of the temperature regime in the five basic ecosystems of oligotrophic bogs in the south taiga zone of Western Siberia in 2011-2016 are presented. The soil temperature regime was studied using the atmospheric-soil measuring complex at different depths from surface to 240 cm. All sites were divided into two groups according the bog water level: flooded sites (hollow and open fen) and drained sites (ridge, tall and low ryam). Waterlogged sites are better warmed in the summer period, and slowly freeze in the winter period. The analysis of the annual cycle of temperature showed that the maximum surface temperature is observed in July. The minimum temperature on the surface observed in February or January. The greatest temperature gradient was recorded in the upper 2 cm layer. The gradient at the open fen was -2 °C·cm-1 in February and 1.1 °C·cm-1 in October. The peak of formation of the seasonally frozen layer occurs at the end of autumn, beginning of winter. The degradation of the seasonally frozen layer was observed both from top and bottom, but degradation from the top is faster.

  2. Fate of leaf-litter N in forest and grassland along a pedo-climatic gradient in south-western Siberia: an in situ 15N-labelling experiment

    NASA Astrophysics Data System (ADS)

    Brédoire, Félix; Zeller, Bernd; Nikitich, Polina; Barsukov, Pavel A.; Rusalimova, Olga; Bakker, Mark R.; Legout, Arnaud; Bashuk, Alexander; Kayler, Zachary E.; Derrien, Delphine

    2017-04-01

    The suitability of Siberia for agriculture is expected to increase in the next decades due to strong and rapid climatic changes, but little is known on the environmental drivers of soil fertility there, especially nitrogen (N). Plant-available N is mainly derived from litter decomposition. South-western (SW) Siberia is located on the transition between several bioclimatic zones that are predicted to shift and extend along with climate change (steppe, forest-steppe, sub-taiga). The soils of this region are formed on a common loess deposit but they are submitted to different climatic conditions and vegetation cover. In the south of the region, typically in steppe/forest-steppe, soil freezes over winter because of a relatively shallow snow-pack, and water shortages are frequent in summer. In the north, typically in sub-taiga, the soil is barely frozen in winter due to a thick snow-pack and sufficient soil moisture in summer. In this study, we characterized the dynamics of leaf litter decomposition and the transfer of N from leaf litter to the soil and back to plants. Four sites were chosen along a climate gradient (temperature, precipitation and snow depth). At each site, we applied 15N-labelled leaf litter on the soil surface in experimental plots in an aspen (Populus tremula L.) forest and in a grassland. Twice a year during three years, we tracked the 15N derived from the decomposing labelled-litter in the organic layers, in the first 15 cm of the soil, and in above-ground vegetation. Soil temperature and moisture were monitored at a daily timestep over three years and soil water budgets were simulated (BILJOU model, Granier et al. 1999). We observed contrasting patterns in the fate of litter-derived 15N between bioclimatic zones. Over three years, along with faster decay rates, the release of leaf litter-N was faster in sub-taiga than in forest-steppe. As such, higher quantities of 15N were transferred into the soil in sub-taiga. The transfer was also deeper there

  3. [Nitrogen pool in northern taiga larch forests of Central Siberia].

    PubMed

    Shugaleĭ, L S; Vedrova, E F

    2004-01-01

    The pools of nitrogen in different blocks of forest ecosystems and its cycle in the soil are considered. It is shown that the bulk of nitrogen concentrates in the soil and dead organic matter (necromass) of an ecosystem. The nitrogen pool of forest litters and soils consists by 83-93% of the inert compounds that cannot be involved in the biological cycle. Mineralization of organic nitrogen-containing substances in the litters and soils usually yields ammonium as an end product. The amount of nitrogen mineralized over the growing season is partially expended for annual plant increment (30-65%) and immobilization (12-17%), with its large proportion being found in the soil.

  4. Object-based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

    NASA Technical Reports Server (NTRS)

    Ransom, Kenneth J.; Montesano, Paul M.; Nelson, Ross F.

    2011-01-01

    The circumpolar taiga-tundra ecotone was delineated using an image segmentation based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 - 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation grouped pixels representing similar tree cover into polygonal features (objects) that form the map of the transition zone. Eachfeature represents an area much larger than the 500m MODIS pixel to characterize thepatterns of sparse forest patches on a regional scale. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1deg longitudinal interval in North America and Eurasia and (2) Landsat-derived Canadianproportion of forest cover for Canada. The adjusted TCC from MODIS VCF shows, on average, greater than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values between 5-20% , or (2) mean adjusted TCC values <5% but with a standard deviation > 5% were used to identify the ecotone.

  5. [EXOSKELETON ABNORMALITIES IN TAIGA TICK FEMALES FROM POPULATIONS OF THE ASIATIC PART OF RUSSIA].

    PubMed

    Nikitin, A Ya; Morozov, I M

    2016-01-01

    Studies of the phenotypic structure of Ixodes persulcatus (Schulze, 1930) populations in relation to their exoskeleton abnormalities are important in both theoretical and practical respects. The data on the species' population structure in Asiatic part of Russia are fragmentary. The goal of the study was to describe taiga tick population structure based on the pattern of females' exoskeleton abnormalities revealed in Asiatic part of Russia. A total of 3872 I. persulcatus females from 16 geographically remote sites of Far Eastern, Siberian, and Ural Federal Districts (FEFD, SFD, and UFD accordingly) were studied. It was demonstrated that all the populations possessed specimens with exoskeleton abnormalities. The «shagreen skin» abnormality was dominant in all these areas. At the same time, the percentage of abnormalities among the specimens collected to the north of 55°N is considerably higher (63.4 ± 3.39 %) than that of samples from the SFD southward territories (33.1 ± 3.43 %). The frequency of abnormalities in its turn is lower (24.4 ± 1.93 %) in the females from the territories with moderate monsoon and moderate continental climate (FEFD) than that in specimens from SFD and UFD areas with sharp continental climate. Thus, such polymorphism of the females' exoskeleton structure may reflect the natural phenogeographical variability of the character rather than the result of the anthropogenic impact. 403

  6. Spaceborne Potential for Examining Taiga-Tundra Ecotone Form and Vulnerability

    NASA Technical Reports Server (NTRS)

    Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

    2016-01-01

    In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable and widespread vegetation change warrants the application of spaceborne data including high-resolution (less than 5m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch-scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data, and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at approximately 40%, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms, and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the

  7. Spaceborne potential for examining taiga-tundra ecotone form and vulnerability

    NASA Astrophysics Data System (ADS)

    Montesano, Paul M.; Sun, Guoqing; Dubayah, Ralph O.; Ranson, K. Jon

    2016-07-01

    In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density, and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, variable, and widespread vegetation change warrants the application of spaceborne data including high-resolution (< 5 m) spaceborne imagery (HRSI) across broad scales for examining TTE form and predicting dynamics. This study analyzes forest structure at the patch scale in the TTE to provide a means to examine both vertical and horizontal components of ecotone form. We demonstrate the potential of spaceborne data for integrating forest height and density to assess TTE form at the scale of forest patches across the circumpolar biome by (1) mapping forest patches in study sites along the TTE in northern Siberia with a multi-resolution suite of spaceborne data and (2) examining the uncertainty of forest patch height from this suite of data across sites of primarily diffuse TTE forms. Results demonstrate the opportunities for improving patch-scale spaceborne estimates of forest height, the vertical component of TTE form, with HRSI. The distribution of relative maximum height uncertainty based on prediction intervals is centered at ˜ 40 %, constraining the use of height for discerning differences in forest patches. We discuss this uncertainty in light of a conceptual model of general ecotone forms and highlight how the uncertainty of spaceborne estimates of height can contribute to the uncertainty in identifying TTE forms. A focus on reducing the uncertainty of height estimates in forest patches may improve depiction of TTE form, which may help explain variable forest responses in the TTE to climate

  8. Bayesian multiproxy temperature reconstruction with black spruce ring widths and stable isotopes from the northern Quebec taiga

    NASA Astrophysics Data System (ADS)

    Gennaretti, Fabio; Huard, David; Naulier, Maud; Savard, Martine; Bégin, Christian; Arseneault, Dominique; Guiot, Joel

    2017-12-01

    Northeastern North America has very few millennium-long, high-resolution climate proxy records. However, very recently, a new tree-ring dataset suitable for temperature reconstructions over the last millennium was developed in the northern Quebec taiga. This dataset is composed of one δ18O and six ring width chronologies. Until now, these chronologies have only been used in independent temperature reconstructions (from δ18O or ring width) showing some differences. Here, we added to the dataset a δ13C chronology and developed a significantly improved millennium-long multiproxy reconstruction (997-2006 CE) accounting for uncertainties with a Bayesian approach that evaluates the likelihood of each proxy model. We also undertook a methodological sensitivity analysis to assess the different responses of each proxy to abrupt forcings such as strong volcanic eruptions. Ring width showed a larger response to single eruptions and a larger cumulative impact of multiple eruptions during active volcanic periods, δ18O showed intermediate responses, and δ13C was mostly insensitive to volcanic eruptions. We conclude that all reconstructions based on a single proxy can be misleading because of the possible reduced or amplified responses to specific forcing agents.

  9. Analyses of changes in vegetation cover in the South and Sub-Taiga of Western Siberia using Landsat data

    NASA Astrophysics Data System (ADS)

    Dyukarev, Egor; Pologova, Nina; Golovatskaya, Eugenia

    2010-05-01

    Understanding human impact on vegetation composition and structure, at scales from the patch to the globe, and capacity to monitor change over time is fundamental research problem to address Global Change and ensure sustainable development. Natural ecosystems at the South and Sob-Taiga zone of Western Siberia are characterized by development of an early successional states, given the projected increase in disturbance, or will be converted into human-dominated terrestrial production systems. Disturbances (e.g., fire, dieback due to insect attacks) appear to be increasing in some regions, leading to fragmentation of natural ecosystems and to a generally "weedier," structurally simpler biosphere with fewer systems in a more ecologically complex old-growth state. The analysis of structure of vegetation cover at two test sites located at the south-west part of the West-Siberian Plain in the South and Sub-Taiga zone was made using LANDSAT space images and ground data. The studied area of the first test site ("Bakchar") is occupied by bogs, paludificated forests and cultivated lands. Test site "Tomsk" covered by cultivated lands in the south, dark coniferous forest complexes an early and old-growth state in the north part. Mire types at the test sites are presented by open fens, ridge-hollow / ridge-lake complexes and pine-shrub-sphagnum communities with different tree height and layer density. During the XX century the vegetation cover was exposed to natural and anthropogenic changes. Comparison of space images from different years (1990, 1999 and 2007) allowed revealing dynamics in vegetation cover. Forest change was calculated using the Disturbance Index (Healey, 2006). Decrease of forest area in 1990-1999 are primary occurs due to intense forest cutting for timber industry and local use. A strong wind have damaged forests between 1990 and 1999 in stripes oriented from south-west to north -east in the prevailing wind direction. Strong winds were registered in 2003

  10. The effect to the water stress to soil CO2 efflux in the Siberian boreal forest

    NASA Astrophysics Data System (ADS)

    Makhnykina, A. V.; Prokishkin, A. S.; Verkhovets, S. V.; Koshurnikova, N. N.

    2017-12-01

    The boreal forests in Siberia covered more than 70% area of this region. Due to the climate change this ecosystems represent a very sensitive and significant source of carbon. In forests, total ecosystem respiration tends to be dominated by soil respiration, which accounts for approximately 69% of this large flux (Janssens et al., 2001). Dynamic global vegetation models predict that soil respiration will increase more than total net primary productivity in response to warmer temperatures and increase in precipitation, the terrestrial carbon sink is expected to decline significantly (Bonan et al., 2003). The aim of the present study was to identify the response of the soil CO2 efflux to the different amount of water input for two highly differentiated years by the precipitation conditions in the middle taiga forests in Central Siberia. The study was conducted in the pine forests in Central Siberia (60°N, 90°E), Russia. We used the automated soil CO2 flux system LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths 5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. We constructed the field experiment based on the addition of different amount of water (0%, 25%, 50% and 100% sites) after each rain event during the growing season. We found that the amount of precipitation have a huge impact to the value of soil CO2 efflux. For the more precipitated year (2015) the fluxes were almost twice higher compared to less precipitated year (2016). The max fluxes during the season in 2015 observed at the site without any water input there and the min one - for the 100% precipitation site (natural rain conditions). In 2016 we identified the opposite response: the max soil efflux demonstrated the site with 100% precipitation conditions (Fig. 1). We also detected the high dependence between the soil temperature and soil CO2 efflux for the site with 0% additional water input in more

  11. NATURAL RADIOACTIVITY OF ZONAL SOILS OF THE EUROPEAN PART OF THE SOVIET UNION (in Russian)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yastrebov, M.T.

    1959-01-01

    Natural radioactivity of zonal soils and of their soil forming rocks up to 220-240 cm in depth as well as of the suprasoil air at a 20 cm altitude from the soil surface has been studled from 29.VM to 13.X 1957 in the natural zones of the European part of the USSR located along the meridian from the Arkhangelsk taiga down to the southern coast of Crimea. The measurements were carried out by mica counters (BFL-T-80 and Si-2b), by an aluminum (AS-2) and glass copper cathode (MS-4) which registers alpha , BETA -soft, BETA -hard and gamma - radiation, respectivelymore » with the aid of a field radiometric device PK-10b and a spherical and hemispherical 9-cm lead shield. It was found that natural radioactivity of zonal soils increased in the following order: highly podzol on carbonate moraine (Arkhangelsk region), sod-highly podzol soil on loess-like loam (Vologodsk region), sodmedium podzol soil on loess-like loam (Moscow region), light-gray forest soil on loess loam (Tula region), powerful leached chernozem on loess-like loam (Kursk region), dark chestnut on carbonate loess-like loam (Kherson region) brown forest on slate schists (Crimea region). A 5-mm superficial layer of the accumulative A: horizon invariably showed maximal natural radioactivity in all kinds of soil surpassing the natural radioactivity value of the lower A/sub 1/ horizon and of all soil horizons and rocks by 2.2-3.5 times. In the podzol A/sub 2/ horizons a decrease of natural radioactivity was mostiy noted as compared with the natural radioactivity value of the accumulative Ai horizon. In the alluvial horizon (B/sub 1/ and B/sub 2/) natural radioactivity increases by 12 to 33% when compared with natural radioactivity of the A: horizon. Most of the soilforming rocks tested showed a lesser natural radioactivity (by 33 to 50%) than natural radioactivity of the accumulative (A/ sub 1/) and alluvial (B/sub 1/ and B/sub 2/) soil horizons which have developed on these rocks. (auth)« less

  12. Influence of increasing active-layer depth and continued permafrost degradation on carbon, water and energy fluxes over two forested permafrost landscapes in the Taiga Plains, NWT, Canada

    NASA Astrophysics Data System (ADS)

    Sonnentag, O.; Baltzer, J.; Chasmer, L. E.; Detto, M.; Marsh, P.; Quinton, W. L.

    2012-12-01

    Recent research suggests an increase in active-layer depth (ALD) in the continuous permafrost zone and degradation of the discontinuous permafrost zone into seasonally frozen. Increasing ALD and continued permafrost degradation will have far-reaching consequences for northern ecosystems including altered regional hydrology and the exposure of additional soil organic carbon (C) to microbial decomposition. These changes might cause positive or negative net feedbacks to the climate system by altering important land surface properties and/or by releasing stored soil organic C to the atmosphere as CO2 and/or CH4. Knowledge gaps exist regarding the links between increasing ALD and/or permafrost degradation, regional hydrology, vegetation composition and structure, land surface properties, and CO2 and CH4 sink-source strengths. The goal of our interdisciplinary project is to shed light on these links by providing a mechanistic understanding of permafrost-thawing consequences for hydrological, ecophysiological and biogeochemical processes at two forested permafrost landscapes in the Taiga Plains, NWT, Canada: Scotty Creek and Havikpak Creek in the discontinuous and in the continuous permafrost zones, respectively (Fig.). The sites will be equipped with identical sets of instrumentation (start: 2013), to measure landscape-scale net exchanges of CO2, CH4, water and energy with the eddy covariance technique. These measurements will be complemented by repeated surveys of surface and frost table topography and vegetation, by land cover-type specific fluxes of CO2 and CH4 measured with a static chamber technique, and by remote sensing-based footprint analysis. With this research we will address the following questions: What is the net effect of permafrost thawing-induced biophysical and biogeochemical feedbacks to the climate system? How do these two different types of feedback differ between the discontinuous and continuous permafrost zones? Is the decrease (increase) in net CO

  13. Total Storage and Landscape Partitioning of Soil Organic Carbon and Phytomass Carbon in Siberia

    NASA Astrophysics Data System (ADS)

    Siewert, M. B.; Hanisch, J.; Weiss, N.; Kuhry, P.; Hugelius, G.

    2014-12-01

    We present results of detailed partitioning of soil organic carbon (SOC) and phytomass carbon (PC) from two study sites in Siberia. The study sites in the Tundra (Kytalyk) and the Taiga (Spasskaya Pad) reflect two contrasting environments in the continuous permafrost zone. In total 57 individual field sites (24 and 33 per study site respectively) have have been sampled for SOC and PC along transects cutting across different land covers. In Kytalyk the sampling depth for the soil pedons was 1 m depth. In Spasskaya Pad where the active layer was significantly deeper, we aimed for 2 m depth or tried to include at least the top of the permafrost. Here the average depth of soil profiles was 152 cm. PC was sampled from 1x1 m ground coverage plots. In Spasskaya Pad tree phytomass was also estimated on a 5x5 m plot. The SOC storage was calculated separately for the intervals 0-30 cm, 30-100 cm and 100-200 cm (the latter only for Spasskaya Pad), as well as for organic layer vs. mineral soil, active layer vs. permafrost and for cryoturbated soil horizons. Landscape partitioning was performed by thematic up-scaling using a vegetation based land cover classification of very high resolution (2x2 m) satellite imagery. Non-Metric Multidimensional Scaling (NMDS) was used to explore the relationship of SOC with PC and different soil and permafrost related variables. The results show that the different land cover classes can be considered distinct storages of SOC, but that PC is not significantly related to total SOC storage. At both study sites the 30-100 cm SOC storage is more important for the total SOC storage than the 0-30 cm interval, and large portions of the total SOC are stored in the permafrost. The largest contribution comes from wetland pedons, but highly cryoturbated individual non-wetland pedons can match these. In Kytalyk the landscape partitioning of SOC mostly follows large scale geomorphological features, while in Spasskaya pad forest type also has a large

  14. Contributions of separate reactions to the acid-base buffering of soils in brook floodplains (Central Forest State Reserve)

    NASA Astrophysics Data System (ADS)

    Sokolova, T. A.; Tolpeshta, I. I.; Rusakova, E. S.

    2016-04-01

    The acid-base buffering of gleyic gray-humus soils developed in brook floodplains and undisturbed southern-taiga landscapes has been characterized by the continuous potentiometric titration of soil water suspensions. During the interaction with an acid, the major amount of protons (>80%) is consumed for the displacement of exchangeable bases and the dissolution of Ca oxalates. In the O and AY horizons, Mn compounds make the major contribution (2-15%) to the acid buffering. The buffer reactions with the participation of Al compounds make up from 0.5 to 1-2% of the total buffering capacity, and the protonation of the surface OH groups of kaolinite consumes 2-3% of the total buffering capacity. The deprotonation of OH groups on the surface of Fe hydroxides (9-43%), the deprotonation of OH groups on the surface of illite crystals (3-19%), and the dissolution of unidentified aluminosilicates (9-14%) are the most significant buffer reactions whose contributions have been quantified during the interaction with a base. The contribution of the deprotonation of OH groups on the surface of kaolinite particles is lower (1-5%) because of the small specific surface area of this mineral, and that of the dissolution of Fe compounds is insignificant. In the AY horizon, the acid and base buffering of soil in the rhizosphere is higher than beyond the rhizosphere because of the higher contents of organic matter and nonsilicate Fe and Al compounds.

  15. Object-Based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

    NASA Technical Reports Server (NTRS)

    Ranson, K. J.; Montesano, P. M.; Nelson, R.

    2011-01-01

    The circumpolar taiga tundra ecotone was delineated using an image-segmentation-based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 to 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation procedure was used to group pixels representing similar tree cover into polygonal features (segmentation objects) that form the map of the transition zone. Each polygon represents an area much larger than the 500 m MODIS pixel and characterizes the patterns of sparse forest patches on a regional scale. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values from5 to 20%, or (2) mean adjusted TCC values greater than 5% but with a standard deviation less than 5% were used to identify the ecotone. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1 degree longitudinal interval in North America and Eurasia, (2) Landsat-derived Canadian proportion of forest cover for Canada, and (3) with canopy cover estimates extracted from airborne profiling lidar data that transected 1238 of the TCC polygons. The adjusted TCC from MODIS VCF shows, on average, less than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. A comparison of the 1238 TCC polygons with profiling lidar measurements yielded an overall accuracy of 67.7%.

  16. Investigation of radionuclide distribution in soil particles in different landscapes

    NASA Astrophysics Data System (ADS)

    Shkinev, V. M.; Korobova, E. M.; Linnik, V. G.

    2012-04-01

    Russian and foreign publications have been analyzed for understanding the role of micro- and nano- particles in distribution and migration of technogenic elements in soils in different landscape conditions. A technique for application of various fractionation methods to separate and study -particles of different size down to micro- and nano-level has been developed. The dry sit method on the first stage of particle separation is recommend to be followed by the membrane filtration method. For obtaining more comprehensive information, combinations of fractionation technique should be chosen taking into account that (1) the efficiency of particles' separation using subsequent technique would be higher than using the preceding one; (2) separation methods should preferably be based on different principles (separation according size, density, charge etc.); (3) initial fractionation should separate particles according to their size, that makes possible to create an even scale for various samples. A study of distribution and balance of technogenic radionuclides' in soil particles of the size intervals 1.0—0.25, 0.25-0.1, 0.1-0.05, 0.05-0.01, 0.01-0.005, 0.005-0.001 and <0.001 mm in the Yenisey flood plain landscapes proved a significant role of both the particle size and the portion of contaminated fraction in contribution to the total radionuclide inventory in the soil layers. Contribution of the silt particles (0,05-0,01 mm) to Cs-137 contamination ranged from 26 to 33,8%, 45% maximum due to "optimal" combination of both factors. Clay fraction was responsible for approximately 30% of Cs-137 contained in soil horizons due to higher sorption capacity. Relatively high correlation between the activity of 152,154Eu and 60 and the content of silt and clay allowed suggesting their incorporation mainly in clay fraction. Selected experimental plots near the Kola NPP (northern taiga) were used to compare soil particles (fractions 140-71; 71-40 and < 40 µm) in their ability to

  17. Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia

    PubMed Central

    Wild, Birgit; Schnecker, Jörg; Knoltsch, Anna; Takriti, Mounir; Mooshammer, Maria; Gentsch, Norman; Mikutta, Robert; Alves, Ricardo J Eloy; Gittel, Antje; Lashchinskiy, Nikolay; Richter, Andreas

    2015-01-01

    Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using 15N pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67°N) to steppe (54°N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest. Key Points We compared soil N dynamics of seven ecosystems along a latitudinal transectShifts in N dynamics suggest a decrease in microbial N limitation with depthWe found no decrease in microbial N limitation from arctic to temperate zones PMID:26693204

  18. [Radioecological situation in the impact zone of the accidental underground nuclear explosion "Kraton-3" in the Republic of Sakha (Yakutia)].

    PubMed

    Sobakin, P I; Gerasimov, Ya R; Chevychelov, A P; Perk, A A; Goryachenkova, T A; Novikov, A P

    2014-01-01

    The paper reports on the results of a ground walking gamma- and gamma-spectrometric survey made in the impact zone of the accidental underground nuclear explosion "Kraton-3". Patterns of migration, 137Cs, 90Sr and Pu distribution in the soil-vegetable cover of the northern taiga on permafrost are considered. Radioeco- logical situation within the territory surveyed is noted as unfavorable.

  19. Assessment of chemical element migration in soil-plant complex of Urov endemic localities of East Transbaikalia

    NASA Astrophysics Data System (ADS)

    Vadim V., Ermakov; Valentina, Danilova; Sabsbakhor, Khushvakhtova; Aklexander, Degtyarev; Sergey, Tyutikov; Victor, Berezkin; Elena, Karpova

    2014-05-01

    The comparative evaluation of the levels of biologically active chemical elements and their migration in the soil-plant complex of two Urov endemic locations in East Transbaikalia (Zolinsky and Uryumkansky) and background areas (Western Baikal region and the western area of the Trans-Baikal region) was conducted. The predominant soil-forming rocks in East Transbaikalia are weathering products of Proterozoic carbonated granitoids PR2. The surface rocks consist from granite, granodiorite, diorite quartz diorite, gabbro, norite, gabbro-norite and other. Soils - mountain and cryogenic meadow forests, mountain permafrost taiga podzolised, meadow alluvial, peaty meadow [2]. The paludification of narrow valleys and thermokarst phenomena are typical in Urov endemic localities. It reflects on the spotted of soil and differentiation of chemical composition of soils and plants. Most of the chemical elements in soils were determined by means of X-ray fluorescence, and trace elements in soils and plants - by atomic absorption spectrometry. The selenium content was measured by spectrofluorimetric method [3]. The research processed by methods of variation statistics. It was found that the soils of two locations of the Urov subregion of the biosphere were more enriched with iron, barium, calcium, uranium, thorium, phosphorus, and to a lesser extent strontium compared to background soils. The ratio of Ca: P was significantly higher in the soil of background areas, and Ca: Sr, on the contrary, in endemic soils. In assessing the migration of trace elements in soil-plant complex by means of the total content of trace elements and biological absorption coefficient found a marked accumulation by plants manganese, chromium, arsenic and weak plants accumulation of cobalt and nickel. Soil landscape is not much different in content of selenium, but its migration in plants was reduced in places of spread of Urov disease [1]. The concentrators of cadmium (leaves of different species of willow

  20. Microbial communities and transformation of carbon compounds in bog soils of the taiga zone (Tomsk oblast)

    NASA Astrophysics Data System (ADS)

    Grodnitskaya, I. D.; Trusova, M. Yu.

    2009-09-01

    Two types of bogs were studied in Tomsk oblast—Maloe Zhukovskoe (an eutrophic peat low-moor bog) and Ozernoe (an oligotrophic peat high-moor bog). The gram-negative forms of Proteobacteria were found to be dominant and amounted to more than 40% of the total population of the microorganisms investigated. In the peat bogs, the population and diversity of the hydrolytic microbial complex, especially of the number of micromycetes, were lower than those in the mineral soils. The changes in the quantitative indices of the total microbiological activity of the bogs were established. The microbial biomass and the intensity of its respiration differed and were also related to the depth of the sampling. In the Zhukovskoe peat low-moor bog, the maximal biomass of heterotrophic microorganisms (154 μg of C/g of peat) was found in the aerobic zone at a depth of 0 to 10 cm. In the Ozernoe bog, the maximal biomass was determined in the zone of anaerobiosis at a depth of 300 cm (1947 μ g of C/g of peat). The molecular-genetic method was used for the determination of the spectrum of the methanogens. Seven unidentified dominant forms were revealed. The species diversity of the methanogens was higher in the oligotrophic high-moor bog than in the eutrophic low-moor bog.

  1. Tertiary structure-related activity of tick defensin (persulcatusin) in the taiga tick, Ixodes persulcatus.

    PubMed

    Isogai, Emiko; Isogai, Hiroshi; Okumura, Kazuhiko; Hori, Hatsuhiro; Tsuruta, Hiroki; Kurebayashi, Yoichi

    2011-01-01

    Defensins are small cysteine-rich cationic proteins found in both vertebrates and invertebrates constituting the front line of host innate immunity. To examine the importance of the tertiary structure of tick defensin in its antimicrobial activity, we synthesized two types of the peptides with tertiary structure or primary one on basis of the information of the sequence in the defensin originated from the taiga tick, Ixodes persulcatus. Chemically synthesized peptides were used to investigate the activity spectrum against Staphylococcus aureus, Borrelia garinii and flora-associated bacteria. Both synthetic peptides showed antimicrobial activity against S. aureus in short-time killing within 1 h, but they do not show the activity against B. garinii, Stenotrophomonas maltophila and Bacillus spp., which were frequently isolated from the midgut of I. persulcatus. The teriary structure brought more potent activity to S. aureus than primary one in short-time killing. We also examined its antimicrobial activity by evaluation of growth inhibition in the presence of the synthetic peptides. Minimum inhibitory concentration (MIC) was ranged from 1.2 to 5.0 μg/ml in tertiary peptide and from 10 to 40 μg/ml in primary peptide, when 10 strains of S. aureus were used. From the curve of cumulative inhibition rates, MIC50 (MIC which half of the strains showed) to S. aureus is about 1.2 μg/ml in the peptide with tertiary structure and about 10 μg/ml in the linear one. Corynebacterium renale is 10 times or more sensitive to tertiary peptide than primary one. In conclusion, the presence of 3 disulfide bridges, which stabilize the molecule and maintain the tertiary structure, is considered to have an effect on their antimicrobial activities against Gram-positive bacteria such as S. aureus.

  2. Soil cover patterns and SOC dynamics impacts on the soil processes, land management and ecosystem services in Central Region of Russia

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan; Chernikov, Vladimir; Yashin, Ivan; Geraskin, Mikhail; Morev, Dmitriy

    2014-05-01

    In the Central Region of Russia (CRR) the soil cover patterns usually play the very important role in the soil forming and degradation processes (SFP & SDP) potential and current rates, soil organic carbon (SOC) dynamics and pools, greenhouse gases (GHG) emissions and soluble SOC fluxes that we need take into attention for better assessment of the natural and especially man-changed ecosystems' services and for best land-use practices development. Central Region of Russia is the biggest one in RF according to its population and role in the economy. CRR is characterized by high spatial variability of soil cover due to as original landscape heterogeneity as complicated history of land-use practices during last 700 years. Our long-term researches include the wide zonal-provincial set of representative ecosystems and soil cover patterns with different types and history of land-use (forest, meadow-steppe and agricultural ones) from middle-taiga to steppe zones with different level of continentality. The carried out more than 30-years region- and local-scale researches of representative natural and rural landscapes in Tver', Yaroslavl', Kaluga, Moscow, Vladimir, Saransk (Mordovia), Kursk, Orel, Tambov, Voronezh and Saratov oblasts give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different soil forming and degradation processes rates and soil organic carbon dynamics due to regionally specific soil-geomorphologic features, environmental and dominated microclimate conditions, land-use current practices and history. The validation and ranging of the limiting factors of SFP and SDP develop¬ment, soil carbon dynamics and sequestration potential, ecosystem (agroecosystem) principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of SOC structure analysis, regional and local GIS, soil spatial patterns detail

  3. First evidence of established populations of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in Sweden.

    PubMed

    Jaenson, Thomas G T; Värv, Kairi; Fröjdman, Isabella; Jääskeläinen, Anu; Rundgren, Kaj; Versteirt, Veerle; Estrada-Peña, Agustín; Medlock, Jolyon M; Golovljova, Irina

    2016-07-01

    The tick species Ixodes ricinus and I. persulcatus are of exceptional medical importance in the western and eastern parts, respectively, of the Palaearctic region. In Russia and Finland the range of I. persulcatus has recently increased. In Finland the first records of I. persulcatus are from 2004. The apparent expansion of its range in Finland prompted us to investigate if I. persulcatus also occurs in Sweden. Dog owners and hunters in the coastal areas of northern Sweden provided information about localities where ticks could be present. In May-August 2015 we used the cloth-dragging method in 36 localities potentially harbouring ticks in the Bothnian Bay area, province Norrbotten (NB) of northern Sweden. Further to the south in the provinces Västerbotten (VB) and Uppland (UP) eight localities were similarly investigated. Ixodes persulcatus was detected in 9 of 36 field localities in the Bothnian Bay area. Nymphs, adult males and adult females (n = 46 ticks) of I. persulcatus were present mainly in Alnus incana - Sorbus aucuparia - Picea abies - Pinus sylvestris vegetation communities on islands in the Bothnian Bay. Some of these I. persulcatus populations seem to be the most northerly populations so far recorded of this species. Dog owners asserted that their dogs became tick-infested on these islands for the first time 7-8 years ago. Moose (Alces alces), hares (Lepus timidus), domestic dogs (Canis lupus familiaris) and ground-feeding birds are the most likely carriers dispersing I. persulcatus in this area. All ticks (n = 124) from the more southern provinces of VB and UP were identified as I. ricinus. The geographical range of the taiga tick has recently expanded into northern Sweden. Increased information about prophylactic, anti-tick measures should be directed to people living in or visiting the coastal areas and islands of the Baltic Bay.

  4. [Influence of meteorological factors on the activity of the adult taiga tick (Ixodes persulcatus Sch., Ixodinae) in St. Petersburg and its environs].

    PubMed

    Osipova, T N; Grigoryeva, L A; Samoylova, E P; Shapar, A O; Bychkova, E M

    2017-01-01

    The article deals with influence of meteorolical factors on the activity of the taiga tick Ixodes persulvatus Sch. in St. Petersburg and its environs. The results of correlation analysis of meteorological data (21 index) and data ticks collected in 1980-2012 allowed determining linear dependence between 11 meteorological indices an average amount of ticks. Factor analysis reduced dimentionality down to 3 indices: sum of temperatures higher than +5.0 °C, sum of precipitation higher than 5 mm per year, and Selyaninov hydrothermal coefficient. It was demonstrated that, at the background of the general tendency for the decrease of the average number of active ticks in the studied territories, correlation between the amount of ticks and meteorological indices can significantly vary as in the correlation density, so in the character and in dependence of microclimatic features of the collecting site. When variability of the mean abundance of ticks during years of investigation is low, the methods of collecting can significantly affect the results of the statistical analysis. This fact must be taken in consideration during prognosis of both dates of the beginning of epidemiological season and its intensity.

  5. [Study on the infection of taiga ticks with Borrelia in the territory of Novosibirsk Scientific Center SB PAS].

    PubMed

    Borgoiakov, V Iu; Fomenko, N V; Panov, V V; Chikova, E D

    2010-01-01

    In our study, Borrelia were revealed in the taiga ticks Ixodes persulcatus collected on vegetation by flagging, as well as in the ticks removed from the people who asked for help in the vaccination center located in the Novosibirsk Scientific Center of the Siberian Branch of Russian Academy of Science (NS SB RAS). By the isolation of Borrelia on BSK-H medum, the occurrence of B. garinii, B. afzelii, and B. miyamotoi was established in the territory of NSC. B. miyamotoi isolates were unstable and lost their ability to growth in later passages. DNA of the same three species of Borrelia was detected by PCR in the samples of ticks, both collected on vegetation by flagging and removed from humans. DNA of B. garinii was recorded most often; DNA of B. afzelii was less frequent; and the least number of positive samples was shown for B. miyamotoi. In the ticks collected on vegetation by flagging, DNA of B. garinii was found in 38.6%, B. afzelii in 9.9%, and B. miyamoboi in 3.9% of samples. In the ticks removed from people, number of positive samples was lesser; so, DNA of B. garinii was detected in 24.2%, B. afzelii in 6.9%, and B. miyamotoi in 5.6% of samples. Mixed infection with two Borrelia species was recorded, and DNA of B. mivamnotoi more often detected simultaneously with DNA of B. garinii.

  6. Spatial and temporal dimensions of fire activity in the fire-prone eastern Canadian taiga.

    PubMed

    Erni, Sandy; Arseneault, Dominique; Parisien, Marc-André; Bégin, Yves

    2017-03-01

    The forest age mosaic is a fundamental attribute of the North American boreal forest. Given that fires are generally lethal to trees, the time since last fire largely determines the composition and structure of forest stands and landscapes. Although the spatiotemporal dynamics of such mosaics has long been assumed to be random under the overwhelming influence of severe fire weather, no long-term reconstruction of mosaic dynamics has been performed from direct field evidence. In this study, we use fire length as a proxy for fire extent across the fire-prone eastern Canadian taiga and systematically reconstruct the spatiotemporal variability of fire extent and fire intervals, as well as the resulting forest age along a 340-km transect for the 1840-2013 time period. Our results indicate an extremely active fire regime over the last two centuries, with an overall burn rate of 2.1% of the land area yr -1 , mainly triggered by seasonal anomalies of high temperature and severe drought. However, the rejuvenation of the age mosaic was strongly patterned in space and time due to the intrinsically lower burn rates in wetland-dominated areas and, more importantly, to the much-reduced likelihood of burning of stands up to 50 years postfire. An extremely high burn rate of ~5% yr -1 would have characterized our study region during the last century in the absence of such fuel age effect. Although recent burn rates and fire sizes are within their range of variability of the last 175 years, a particularly severe weather event allowed a 2013 fire to spread across a large fire refuge, thus shifting the abundance of mature and old forest to a historic low. These results provide reference conditions to evaluate the significance and predict the spatiotemporal dynamics and impacts of the currently strengthening fire activity in the North American boreal forest. © 2016 John Wiley & Sons Ltd.

  7. Soil greenhouse gases fluxes in forest - fallow succession at the Central Forest Reserve in European Russia

    NASA Astrophysics Data System (ADS)

    Komarova, Tatiana; Vasenev, Ivan

    2017-04-01

    One of the principal factors influencing the current level of the greenhouse fluxes are land-use changes, including the forest restoration in fallow lands, which is widespread at the Central Region of Russia. The comprehensive environmental studies of soil greenhouse fluxes have been done in comparable sites with different stages of the forest-fallow successions in the southern part of the Central Forest Reserve with spruce domination in the mature forest - representative southern-taiga ecosystems. Seasonal and diurnal dynamics CO2 fluxes measurements were carried out in situ using a mobile gas analyzer Li-820 with soil exposure chambers and parallel observation of air temperature, soil temperature and moisture. Also, every ten days the soil air has been sampled in the vials for further CO2, CH4 and N2O flux measurements by the stationary gas chromatograph. Within forest-fallow successions there are shown the litter gradual development, humus-accumulative horizon differentiation, soil acidity and bulk density increasing. At the same time there is enough obvious in the down part of past-arable horizon gradual restoration of the podzolic horizon. The monitoring results have shown the essential decreasing of soil CO2 fluxes (in 2 times) in frame of successions. The maximum CO2 fluxes have been fixed in July with optimal soil temperature/moisture ratio. In the middle of July the maximum CO2 emission is observed in fallow grassland (34,1 g CO2 / m2day), that is almost in 2-times more than in spruce-forest after fallow stage of 120-150 years. It is important that soil CO2 fluxes essentially increase with soil temperature rise (with up to R = 0,75) and drop soil moisture (with up to R = - 0,66). During the day, the most intense soil CO2 fluxes have been observed from case of 12:00 to 18:00. The maximum CO2 flux has been recorded at 15:00 in the fallow grassland (23 g CO2 / m2 day). In the forest-fallow stage of 10-15 years the maximum soil CO2 flux observed at 12 hours

  8. Global assessment of soil organic carbon stocks and spatial distribution of histosols: the Machine Learning approach

    NASA Astrophysics Data System (ADS)

    Hengl, Tomislav

    2016-04-01

    tools. Results of model fitting using the R packages nnet, randomForest and the h2o software (machine learning functions) show that significant models can be fitted for soil classes, bulk density (R-square 0.76), soil organic carbon (R-square 0.62) and coarse fragments (R-square 0.59). Consequently, we were able to estimate soil organic carbon stock for majority of the land mask (excluding permanent ice) and detect patches of landscape containing mainly organic soils (peat and similar). Our results confirm that hotspots of soil organic carbon in Tropics are peatlands in Indonesia, north of Peru, west Amazon and Congo river basin. Majority of world soil organic carbon stock is likely in the Northern latitudes (tundra and taiga of the north). Distribution of histosols seems to be mainly controlled by climatic conditions (especially temperature regime and water vapor) and hydrologic position in the landscape. Predicted distributions of organic soils (probability of occurrence) and total soil organic carbon stock at resolutions of 1 km and 250 m are available via the SoilGrids.org project homepage.

  9. Environmental and societal consequences of a possible CO/sub 2/-induced climate change. Volume II, Part 14. Research needed to determine the present carbon balance of northern ecosystems and the potential effect of carbon-dioxide-induced climate change

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, P.C.

    1982-10-01

    Given the potential significance of northern ecosystems to the global carbon budget it is critical to estimate the current carbon balance of these ecosystems as precisely as possible, to improve estimates of the future carbon balance if world climates change, and to assess the range of certainty associated with these estimates. As a first step toward quantifying some of the potential changes, a workshop with tundra and taiga ecologists and soil scientists was held in San Diego in March 1980. The first part of this report summarizes the conclusions of this workshop with regard to the estimate of the currentmore » areal extent and carbon content of the circumpolar arctic and the taiga, current rates of carbon accumulation in the peat in the arctic and the taiga, and predicted future carbon accumulation rates based on the present understanding of controlling processes and on the understanding of past climates and vegetation. This report presents a finer resolution of areal extents, standing crops, and production rates than was possible previously because of recent syntheses of data from the International Biological Program and current studies in the northern ecosystems, some of which have not yet been published. This recent information changes most of the earlier estimates of carbon content and affects predictions of the effect of climate change. The second part of this report outlines research needed to fill major gaps in the understanding of the role of northern ecosystems in global climate change.« less

  10. Microrelief and vegetation as the factors of spatial redistribution of nutrients in the soils of forest ecosystems

    NASA Astrophysics Data System (ADS)

    Chernitsova, Olga; Krechetov, Pavel

    2017-04-01

    The study is aimed at the identifying factors and mechanisms controlling the redistribution of nutrients in the profile of sod-podzolic soils (Umbric Albeluvisols Abruptic in WRB, 2006). The data of chemical analyzes of soil samples of soddy-pale-podzolic soils under mixed coniferous-deciduous forests, picked from the genetic horizons of 28 soil profiles up to the depth of 120-150 cm in the key area with a polygonal-block microrelief (58.39°N, 56.52°E) were used. Soil profiles were placed at the key area considering vegetation and microrelief. Samples were analyzed for humus content, available forms of N, P, K, Ca, Mg and soil texture. Published data on the capacity and the structure of biogeochemical cycling in forest phytocenoses of different ages in the southern taiga were summarized. Field sketches were used for the construction of the digital elevation model of the key area and for plotting the vegetation map showing the crowns' projections of trees and shrubs of different species. Using spatial interpolation in GIS, series of schematic maps were created that characterize the depth of the lower boundary of genetic horizons and their thickness, as well as the texture of the different soil horizons, humus content and distribution of nutrients at different depths. These schematic maps were analyzed for patterns of radial and lateral differentiation of all examined features. Pronounced textural differentiation of soils of micro-elevations and poor textural differentiation of soil of micro-depressions are revealed. It is shown that in the soils with the positions from micro-elevations through flat surfaces to micro-depressions the humus content in the upper layers (horizon A) increases 1.6-1.7 times, the content of nitrogen ‒ 1.4-1.5, phosphorus ‒ 2.6 8.4, calcium and magnesium cations ‒ 1.8-2.9 times. This differentiation in nutrients' content is coming along with the settlement of more demanding to soil fertility plants in micro-depressions. Also the

  11. Hydrology and Climatology of the Caribou-Poker Creeks Research Watershed, Alaska,

    DTIC Science & Technology

    1982-10-01

    system the watershed falls within the Inter- dense brush of willow, alder and dwarf birch in ior Alaska Forest ( Taiga ) designation. open forests near...and C.T. Cushwina (1973) Research stream flow characteristics in the discontinuous opportunities and needs in the Taiga of Alaska. permafrost zone of...edition. taiga research watershed. Institute of Water Re- linkenson, W.M. nB. Lotspeich and lW. Mueller sources, University of Alaska, Fairbanks, Alaska

  12. Variability in methane emissions from West Siberia's shallow boreal lakes on a regional scale and its environmental controls

    NASA Astrophysics Data System (ADS)

    Sabrekov, Aleksandr F.; Runkle, Benjamin R. K.; Glagolev, Mikhail V.; Terentieva, Irina E.; Stepanenko, Victor M.; Kotsyurbenko, Oleg R.; Maksyutov, Shamil S.; Pokrovsky, Oleg S.

    2017-08-01

    Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatiotemporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July-August 2014 within the West Siberian middle and southern taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m-2 h-1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m-2 h-1 for southern taiga lakes, respectively. Pronounced flux variability was found during measurements on individual lakes, between individual lakes and between zones. To analyze these differences and the influences of environmental controls, we developed a new dynamic process-based model. It shows good performance with emission rates from the southern taiga lakes and poor performance for individual lakes in the middle taiga region. The model shows that, in addition to well-known controls such as temperature, pH and lake depth, there are significant variations in the maximal methane production potential between these climatic zones. In addition, the model shows that variations in gas-filled pore space in lake sediments are capable of controlling the total methane emissions from individual lakes. The CH4 emissions exhibited distinct zonal differences not only in absolute values but also in their probability density functions: the middle taiga lake fluxes were best described by a lognormal distribution while the southern taiga lakes followed a power-law distribution. The latter suggests applicability of self-organized criticality theory for methane emissions from the southern taiga zone, which could help to explain the strong variability within individual lakes.

  13. Climate-induced mortality of "dark needle conifer" in Siberian taiga

    NASA Astrophysics Data System (ADS)

    Kharuk, Viacheslav; Im, Sergei; Petrov, Ilya

    2017-04-01

    Within Siberia fir (Abies sibirica) and Siberian pine (Pinus sibirica) (so called "dark needle conifers", DNC) mortality increased in the southern part of the DNC range. Siberian pine and fir showed decreased radial growth increment within southern Siberia since the 1980s with increasing mortality recorded since the year 2000. Tree ring width was strongly correlated with vapor pressure deficit, aridity and root zone moisture. Water stress from droughts made trees more susceptible to insect attacks causing mortality in about 10% of DNC stands in southern Siberia. Biogeographically, tree mortality was located within the DNC - forest-steppes transition. Tree mortality was significantly correlated with drought and soil moisture anomalies. Within the interior of the DNC range mortality occurred within relief features with high water stress risk (i.e., steep convex south facing slopes with shallow well-drained soils). In general, DNC mortality in Siberia was induced by increased aridity and severe drought (inciting factors) in synergy with biotic attacks (contributing factor). In particular, bark beetle Polygraphus proximus made a strong input on the fir mortality. In future climate scenarios with predicted increase in aridity DNC could be eliminated from the southern part of its current range and will be replaced by drought-resistant conifers and broadleaf species (e.g., Larix sibirica, Pinus sylvestris, and Betula pubescence).

  14. Seasonally frozen layer in natural and drained peatlands at the South of West Siberia, Russia

    NASA Astrophysics Data System (ADS)

    Dyukarev, Egor; Kiselev, Maxim; Voropay, Nadezhda; Preis, Yulia

    2017-04-01

    The temperature regime of soils in natural and drained peatlands at Bakchar bog located in the South Taiga zone of West Siberia is studied. Soil temperature for depths up to 320 cm was registered using autonomous temperature profile recorder during the period from August 2010 to September 2016. Maximal and minimal temperatures were registered at surface in July and February, consequently. Extreme soil temperatures at 320 cm depth shifts to December (maximum) and July (minimum) reducing absolute values. Annual peat soil temperature amplitude decrease with depth from 21,8 °C on surface to 1,1 °C at 320 cm. The analysis of daily, month and annual mean data of temperature in peat soil has shown that seasonally frozen layer was registered up to 20-60 cm depth. The duration of seasonally freeze layer existence varies from 130 to 180 days. Drained peatlands with the lowest water table have highest freeze depth. Soil at water-logged sedge-sphagnum fen in winter is warmer than soil in ryam ecosystem and mineral soil at upland. Maximal freezing depth in peatlands is up to 3 times lower than at drain areas.

  15. Arctic ecosystem reaction on permafrost melting as a result of 40 years anthropogenic impact

    NASA Astrophysics Data System (ADS)

    Petrzhik, Nataliya; Matyshak, George; Myshonkov, Alexander; Petrov, Dmitry

    2017-04-01

    Arctic ecosystems are sensitive indicators of environmental change. The increasing of anthropogenic impact perturb the natural ecosystems balance, first of all significant changes happen in soil and vegetation. It is necessary to study the permafrost ecosystem response, as the permafrost covers the quarter of the world and more than a half of Russia. Since 1960 the oil and gas industry grows in Russia. The hydrocarbons can be transferred by pipelines only in the heated state. The main effect of construction and operation of pipeline is the heating of soil and permafrost degradation. The goal of this study was to estimate the response of landscapes and permafrost ecosystem of north of West Siberia to the cumulative action of pipelines. The main objective was to investigate the warming impact on the properties and function of the soil along the pipelines in permafrost zone. The studied object was vegetation and soil cover of the north of Western Siberia ecosystems after the action of pipelines. The areas with maximum effect of heat lines were selected by remote sensing. Ten transects of 50 meters in length with sampling points every 5 meters from pipeline to undisturbed background area were selected in three different natural zones. The soil and vegetation cover was described, sampled, active layer of soil and the power of organic horizon were measured, the hydrothermal regime of soils in a layer of 0-10 cm was measured, the emission of greenhouse gas was studied. In the laboratory, the content of labile carbon, microbial biomass carbon, basal and substrate-induced respiration were measured. The main effect of the pipelines impact is the active degradation of permafrost and changes in hydrothermal settings. From background to broken areas the following settings changing: the depth of thawing increase in 10 times; the soil temperature changes from 4 to 10,5 ° C in taiga, from 4.5 to 13,5 ° C in tundra, from 5.5 to 12 ° C in forest-tundra; the soil moisture reduces

  16. SMALL MAMMAL BIOCLIMATE STUDIES IN NORTHERN REGIONS

    DTIC Science & Technology

    northern regions. Two major divisions are established - the tundra (arctic treeless region) and the taiga (subarctic spruce forest). Further subdivisions...of taiga small mammals are analyzed. Points of potential value to the Air Force are drawn from studies on the importance of topographical

  17. Permafrost thaw and fire history: implications of boreal tree cover changes on land surface properties and turbulent energy fluxes in the Taiga Plains, Canada

    NASA Astrophysics Data System (ADS)

    Sonnentag, Oliver; Helbig, Manuel; Payette, Fanny; Wischnewski, Karoline; Kljun, Natascha; Chasmer, Laura; Pappas, Christoforos; Detto, Matteo; Baltzer, Jennifer; Quinton, William; Marsh, Philip

    2016-04-01

    Given their large areal coverage, high carbon densities, and unique land surface properties and disturbance regimes (e.g., wildfires), the world's boreal forests are integral components of the global and regional climate systems. A large portion of boreal forests contain permafrost, i.e., perennially cryotic ground. In the Taiga Plains ecozone in northwestern Canada, the northernmost boreal forests grow on cold (<-1.5 °C) and thick (>100 m) continuous permafrost (>90 % in areal extent). More southerly boreal forests occur in areas with discontinuous (>50 - 90 % in areal extent), sporadic (>10 - 50 % in areal extent) and isolated permafrost (<10 % in areal extent). Using annual MODIS Percent Tree Cover (PTC) data from the MOD44B product in combination with spatial information on fire history, and permafrost and drainage characteristics, we show that in low-lying, poorly-drained areas along the southern fringe of permafrost, thawing induces widespread decreases in PTC and dominates over PTC increases due to post-fire regrowth. In contrast, PTC appears to be slightly increasing in the central and northern Taiga Plains with more stable discontinuous and continuous permafrost, respectively. While these increases are partly explained by post-fire regrowth, more favourable growing conditions may also contribute to increasing PTC. To better understand the implications of permafrost thaw on land surface properties (e.g., aerodynamic conductance for heat [ga] and surface conductance for water vapour [gs]), and the turbulent fluxes of latent (LE) and sensible heat (H) along the southern fringe of permafrost, we examined nested eddy covariance flux measurements made at two nearby locations at Scotty Creek (61°18' N; 121°18' W) starting May 2013. The low-lying, poorly-drained southern portion of this 152 km2-watershed contains rapidly thawing sporadic permafrost resulting in a highly dynamic mosaic dominated by decreasing forested permafrost peat plateaus, and increasing

  18. The dendroclimatic proxies from the northern Quebec taiga in the PAGES 2K network: recent advances and future developments.

    NASA Astrophysics Data System (ADS)

    Gennaretti, Fabio; Naulier, Maud; Arseneault, Dominique; Savard, Martine; Bégin, Christian; Boucher, Etienne; Bégin, Yves; Guiot, Joël

    2016-04-01

    Northeastern North America was historically underrepresented in the network of climate proxies used for climate reconstructions over the last two millennia. Indeed, in North America most high-resolution climate proxies are long tree-ring chronologies but, in Northeastern North America, these chronologies are highly challenging due to short tree longevity, high frequency and severity of wildfires and remoteness of many areas. Here, we will present the efforts accomplished during the last decade by our team in developing millennial-long tree-ring chronologies in the northern Quebec taiga. We sampled black spruce [Picea mariana (Mill.) B.S.P] subfossil tree remains naturally fallen in the littoral zone of six lakes to build six site-specific ring-width chronologies as well as two chronologies of stable isotope ratios (δ18O and δ13C in tree-ring cellulose). These chronologies, which are now included in the PAGES 2K network, were independently used to reconstruct summer temperature variations showing a well-expressed Medieval Climate Anomaly and the impact of volcanic and solar forcings at regional scale. We will also discuss non-climatic influences on these chronologies (i.e. wildfires and sampling height inconsistency), as well as the ongoing effort to extend the reconstructions in time to cover the last 2500 years. Finally, a new European funded project called MAIDEN-SPRUCE will be introduced. Within MAIDEN-SPRUCE, we will use a data-model approach to improve our understanding of the links between forests and climate over the last millennium. More specifically, we will adapt the process-based ecophysiological model MAIDENiso to investigate factors influencing the growth and underlying biogeochemical processes of black spruce. One of our objectives is to provide the first multi-proxy (ring widths and δ18O and δ13C in tree-ring cellulose) regional climate reconstruction in Eastern North America over the last millennium taking into account mechanistic rules

  19. Soviet Developments in Weather Modification, Climate Modification, and Climatology

    DTIC Science & Technology

    1975-09-01

    48-55. n 3. Mikhaylov, Yu. P. The environmental impact on the taiga geosystems of the diversion of northern river runoff. (VI th...expanded session of the Scientific Council of the Siberian Branch of the USSR Academy of Sciences on the complex reclamation of taiga territories

  20. The Russians are coming - aren't they? Siberian moth in European forests

    Treesearch

    Yuri N. Baranchikov; Vladimir M. Pet' ko; Vladimir L. Ponomarev

    2007-01-01

    Dendrolimus superans sibiricus Tschtv. (Lepidoptera: Lasiocampidae) is the most destructive defoliator of the coniferous taiga forest in Siberia and the Russian Far East. Outbreaks of this pest species are the primary biological factor influencing change in forest cover in the southern taiga subzone with enormous ecological and social consequences (...

  1. Monitoring of environmental conditions in taiga forests using ERS-1 SAR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rignot, E.; Way, J.B.; McDonald, K.

    1994-08-01

    Synthetic-aperture radar images of forest site near Manley Hot Springs (64[degree]N, 151[degree]W), Alaska, were collected between August 1991 and December 1991, day and night, every 3 days, at C-band frequency ([lambda] = 5.7 cm), vertical receive and transmit polarization, by the European Space Agency First Remote Sensing Satellite, ERS-1. During the same period, air and soil temperatures and dielectric and gravimetric moisture properties of the forest canopy and forest floor were monitored in three forest stands dominated, respectively, by black spruce (Picea mariana), white spruce (Picea glauca), and balsam poplar (Populus balsamifera). The calibrated ERS-1 radar backscatter values, [sigma][degree], ofmore » the forest stands are shown to exhibit a pronounced temporal pattern, with little separability between tree species. The largest change in [sigma][degree], a 3-dB decrease almost independent of tree species, is observed in early winter when the soil and vegetation freeze. In the summer, temporal fluctuations in [sigma][degree] are about 1--2 dB in magnitude, depending on tree species. Diurnal variations in [sigma][degree] are as large as 2 dB during fall freeze-up, and less than 1 dB in summer and winter. These temporal variations in radar backscatter from the forest are interpreted using the MIMICS radar backscatter model and the in situ surface observations as due to changes in the dielectric properties of the forest floor and forest canopy induced by precipitation (summer), drought (fall), and freezing (fall-winter) events. In winter, [sigma][degree] increases across the entire landscape, probably because of volume scattering from large depth hoar ice crystals forming in the snow pack.« less

  2. Soil properties, soil functions and soil security

    NASA Astrophysics Data System (ADS)

    Poggio, Laura; Gimona, Alessandro

    2017-04-01

    Soil plays a crucial role in the ecosystem functioning such as food production, capture and storage of water, carbon and nutrients and in the realisation of a number of UN Sustainable Developments Goals. In this work we present an approach to spatially and jointly assess the multiple contributions of soil to the delivery of ecosystem services within multiple land-use system. We focussed on the modelling of the impact of soil on sediment retention, carbon storage, storing and filtering of nutrients, habitat for soil organisms and water regulation, taking into account examples of land use and climate scenarios. Simplified models were used for the single components. Spatialised Bayesian Belief networks were used for the jointly assessment and mapping of soil contribution to multiple land use and ecosystem services. We integrated continuous 3D soil information derived from digital soil mapping approaches covering the whole of mainland Scotland, excluding the Northern Islands. Uncertainty was accounted for and propagated across the whole process. The Scottish test case highlights the differences in roles between mineral and organic soils and provides an example of integrated study assessing the contributions of soil. The results show the importance of the multi-functional analysis of the contribution of soils to the ecosystem service delivery and UN SDGs.

  3. The Petsamo-Kirkenes Operation: Soviet Breakthrough and Pursuit in the Arctic, October 1944 (Leavenworth Papers, Number 17)

    DTIC Science & Technology

    1989-09-01

    Roschmann , "Small Unit Tactics, Combats in Taiga and Tundra," Foreign Military Studies no. MS P-060m (Historical Division, U.S. Army, Europe, 1952), 148...Brockelmann, Klaus, and Hans Roschmann . "Small Unit Tactics, Combats in Taiga and Tundra." Foreign Military Studies no. MS P-060m. Historical Division

  4. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region (Version 2.0)

    DTIC Science & Technology

    2007-09-01

    07-24 102 Viereck, L. A., K. Van Cleve, and C. T. Dyrness. 1986. Forest ecosystem distribution in the Taiga environment, Chapter 3. In Forest...ecosystems in the Alaska Taiga : A synthesis of structure and function. ed. K. Van Cleve, F. S. Chapin III, P. W. Flanagan, L. A. Viereck, and C. T

  5. Sources of particulate organic matter discharged by the Lena River using lignin phenols

    NASA Astrophysics Data System (ADS)

    Winterfeld, M.; Trojahn, S.; Hefter, J.; Pittauer, D.; Zubrzycki, S.; Han, P.; Rethemeyer, J.; Mollenhauer, G.

    2016-12-01

    Particulate organic matter (POM) discharged by rivers and deposited offshore their mouths is generally assumed to record an integrated signal from the watershed and therefore provides an archive of past environmental changes. Yet, in large river systems the riverine POM might be trapped in flood plains and the lower reaches resulting in an inefficient transport of POM particularly from the distal parts of the watershed. Further, the POM likely undergoes degradation during transport from source to sink. The Lena River is one of these large river systems stretching from 53°N to 71°N in central Siberia. The watershed can be broadly divided into two different biomes, taiga in the south and tundra in the northernmost part. The relative contribution of these biomes to the POM load of the river and its discharge to the ocean as well as the changes it is undergoing during transport are not well understood. Here we present the lignin phenol composition of different grain size fractions (bulk, 2mm-63µm, <63µm) of soil samples taken along a latitudinal transect (63°N to 72°N) as well as in marine surface sediments and two short sediment cores covering the last 120 years offshore the main Lena discharge channels. The lignin phenol composition of the soil samples (bulk, 2mm-63µm, <63µm) reflects the change in vegetation from south to north with increasing contribution of tundra vegetation. The degree of degradation between the soil sample locations as well as grain size fractions was very heterogeneous and did not show a clear trend. However, the POM seems to be slightly more degraded in the tundra, which is unexpected as the summer period when degradation in the upper thawed part of the soil can take place is shorter in the tundra compared to the southern taiga region. The marine surface sediments were dominated by gymnosperm-derived POM, particularly close to the river mouth and in the <63µm fraction. Because of the large heterogeneity of organic matter degradation

  6. Succession change of microorganisms on plant waste decomposition in simulation modelling field experiment

    NASA Astrophysics Data System (ADS)

    Vinogradova, Julia; Perminova, Evgenia; Khabibullina, Fluza; Kovaleva, Vera; Lapteva, Elena

    2016-04-01

    Plant waste decomposition processes are closely associated with living activity of soil microbiota in aboveground ecosystems. Functional activity of microorganisms and soil invertebrates determines plant material transformation rate whereby changes in plant material chemical composition during destruction - succession change of soil biota. The purpose of the work was revealing the mechanism of microorganisms succession change during plant waste decomposition in middle-taiga green-moss spruce forests and coniferous-deciduous secondary stands formed after earlier cut bilberry spruce forests. The study materials were undisturbed bilberry spruce forest (Sample Plot 1 - SP1) and coniferous-deciduous secondary stands which were formed after tree cutting activities of 2001-2002 (SP2) and 1969 and 1970 (SP3). Plant material decomposition intensity was determined in microcosms isolated into kapron bags with cell size of 1 mm. At SP1 and SP2, test material was living mosses and at SP3 - fallen birch and aspen leaves. Every test material was exposed for 2 years. Destruction rate was calculated as a weight loss for a particular time period. Composition of micromycetes which participated in plant material decomposition was assessed by the method of inoculation of soil extract to Getchinson's medium and acidified Czapek's medium (pH=4.5). Microbe number and biomass was analyzed by the method of luminescent microscopy. Chemical analysis of plant material was done in the certified Ecoanalytical Laboratory of the Institute of Biology Komi SC UrD RAS. Finally, plant material destruction intensity was similar for study plots and comprised 40-44 % weight loss for 2 years. The strongest differences in plant material decomposition rate between undisturbed spruce forests and secondary after-cut stands were observed at first stages of destruction process. In the first exposition year, mineralizing processes were most active in undisturbed spruce forest. Decomposition rate in cuts at that

  7. iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping

    NASA Astrophysics Data System (ADS)

    Dietrich, Peter; Werban, Ulrike; Sauer, Uta

    2010-05-01

    High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the

  8. Assessment the effect of homogenized soil on soil hydraulic properties and soil water transport

    NASA Astrophysics Data System (ADS)

    Mohawesh, O.; Janssen, M.; Maaitah, O.; Lennartz, B.

    2017-09-01

    Soil hydraulic properties play a crucial role in simulating water flow and contaminant transport. Soil hydraulic properties are commonly measured using homogenized soil samples. However, soil structure has a significant effect on the soil ability to retain and to conduct water, particularly in aggregated soils. In order to determine the effect of soil homogenization on soil hydraulic properties and soil water transport, undisturbed soil samples were carefully collected. Five different soil structures were identified: Angular-blocky, Crumble, Angular-blocky (different soil texture), Granular, and subangular-blocky. The soil hydraulic properties were determined for undisturbed and homogenized soil samples for each soil structure. The soil hydraulic properties were used to model soil water transport using HYDRUS-1D.The homogenized soil samples showed a significant increase in wide pores (wCP) and a decrease in narrow pores (nCP). The wCP increased by 95.6, 141.2, 391.6, 3.9, 261.3%, and nCP decreased by 69.5, 10.5, 33.8, 72.7, and 39.3% for homogenized soil samples compared to undisturbed soil samples. The soil water retention curves exhibited a significant decrease in water holding capacity for homogenized soil samples compared with the undisturbed soil samples. The homogenized soil samples showed also a decrease in soil hydraulic conductivity. The simulated results showed that water movement and distribution were affected by soil homogenizing. Moreover, soil homogenizing affected soil hydraulic properties and soil water transport. However, field studies are being needed to find the effect of these differences on water, chemical, and pollutant transport under several scenarios.

  9. Soil microbiology and soil health assessment

    USDA-ARS?s Scientific Manuscript database

    Soil scientists have long recognized the importance of soil biology in ecological health. In particular, soil microbes are crucial for many soil functions including decomposition, nutrient cycling, synthesis of plant growth regulators, and degradation of synthetic chemicals. Currently, soil biologis...

  10. Influence of soil moisture on soil respiration

    NASA Astrophysics Data System (ADS)

    Fer, Miroslav; Kodesova, Radka; Nikodem, Antonin; Klement, Ales; Jelenova, Klara

    2015-04-01

    The aim of this work was to describe an impact of soil moisture on soil respiration. Study was performed on soil samples from morphologically diverse study site in loess region of Southern Moravia, Czech Republic. The original soil type is Haplic Chernozem, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). Soil samples were collected from topsoils at 5 points of the selected elevation transect and also from the parent material (loess). Grab soil samples, undisturbed soil samples (small - 100 cm3, and large - 713 cm3) and undisturbed soil blocks were taken. Basic soil properties were determined on grab soil samples. Small undisturbed soil samples were used to determine the soil water retention curves and the hydraulic conductivity functions using the multiple outflow tests in Tempe cells and a numerical inversion with HYDRUS 1-D. During experiments performed in greenhouse dry large undisturbed soil samples were wetted from below using a kaolin tank and cumulative water inflow due to capillary rise was measured. Simultaneously net CO2 exchange rate and net H2O exchange rate were measured using LCi-SD portable photosynthesis system with Soil Respiration Chamber. Numerical inversion of the measured cumulative capillary rise data using the HYDRUS-1D program was applied to modify selected soil hydraulic parameters for particular conditions and to simulate actual soil water distribution within each soil column in selected times. Undisturbed soil blocks were used to prepare thin soil sections to study soil-pore structure. Results for all soil samples showed that at the beginning of soil samples wetting the CO2 emission increased because of improving condition for microbes' activity. The maximum values were reached for soil column average soil water content between 0.10 and 0.15 cm3/cm3. Next CO2 emission decreased since the pore system starts filling by water (i.e. aggravated conditions for microbes

  11. Alaska Melilotus invasions: Distribution, origin, and susceptibility of plant communities

    USGS Publications Warehouse

    Conn, J.S.; Beattie, K.L.; Shephard, M.A.; Carlson, M.L.; Lapina, I.; Hebert, M.; Gronquist, R.; Densmore, R.; Rasy, M.

    2008-01-01

    Melilotus alba and M. officinalis were introduced to Alaska in 1913 as potential forage crops. These species have become naturalized and are now invading large, exotic plant-free regions of Alaska. We determined distributions of M. alba and M. officinalis in Alaska from surveys conducted each summer from 2002 to 2005. Melilotus alba and M. officinalis occurred at 721 and 205 sites, respectively (39,756 total sites surveyed). The northward limit for M. alba and M. officinalis was 67.15??N and 64.87??N, respectively. Both species were strictly associated with soil disturbance. Melilotus alba extended no farther than 15 m from road edges except where M. alba on roadsides met river floodplains and dispersed downriver (Matanuska and Nenana Rivers). Melilotus has now reached the Tanana River, a tributary of the Yukon River. Populations on floodplains were most extensive on braided sections. On the Nenana River, soil characteristics did not differ between where M. alba was growing versus similar areas where it had not yet reached. The pH of river soils (7.9-8.3) was higher than highway soils (7.3). Upland taiga plant communities grow on acid soils which may protect them from invasion by Melilotus, which prefer alkaline soils; however, early succession communities on river floodplains are susceptible because soils are alkaline. ?? 2008 Regents of the University of Colorado.

  12. Preliminary estimating the contemporary sedimentation trend in dry valley bottoms of first-order catchments of different landscape zones of the Russian Plain using the 137Cs as a chronomarker

    NASA Astrophysics Data System (ADS)

    Sharifullin, A.; Gusarov, A.; Gafurov, A.; Essuman-Quainoo, B.

    2018-01-01

    A general trend of erosion processes over the last 50-60 years can be estimated by dating sediments washed off from arable lands and accumulated in the first-order dry valleys bottoms. Three small (first-order) catchments were chosen as objects of the study. They are located, respectively, in the southern part of the taiga zone, the zone of temperate broad-leaf forests and the forest-steppe zone of the Russian Plain. To date the sediments accumulated in the bottoms the radioactive caesium-137 (137Cs) of global (since 1954) and Chernobyl origin (1986) had been used as a chronomarker. The average (for all the catchments) sedimentation rates during the global 137Cs fallout period (1963(1954)-1986) are at least 0.88-2.71 cm per year.For the period that has passed since the Chernobyl accident (1986-2015(2016)) the average rates were 0.15-1.07 cm per year. The greatest reduction in the sedimentation rates is observed in the subzone of the southern taiga, the lowest one is in the forest-steppe zone of the Russian Plain. The main reason for such significant reduction in the rates of sedimentation of the soil erosion products in the dry valley bottoms was a reduction of surface runoff within the catchments during a snowmelt period, as well as crop-rotation changes there.

  13. Measuring soil sustainability via soil resilience.

    PubMed

    Ludwig, Marie; Wilmes, Paul; Schrader, Stefan

    2018-06-01

    Soils are the nexus of water, energy and food, which illustrates the need for a holistic approach in sustainable soil management. The present study therefore aimed at identifying a bioindicator for the evaluation of soil management sustainability in a cross-disciplinary approach between soil science and multi-omics research. For this purpose we first discuss the remaining problems and challenges of evaluating sustainability and consequently suggest one measurable bioindicator for soil management sustainability. In this concept, we define soil sustainability as the maintenance of soil functional integrity. The potential to recover functional and structural integrity after a disturbance is generally defined as resilience. This potential is a product of the past and the present soil management, and at the same time prospect of possible soil responses to future disturbances. Additionally, it is correlated with the multiple soil functions and hence reflecting the multifunctionality of the soil system. Consequently, resilience can serve as a bioindicator for soil sustainability. The measurable part of soil resilience is the response diversity, calculated from the systematic contrasting of multi-omic markers for genetic potential and functional activity, and referred to as potential Maximum Ecological Performance (MEPpot) in this study. Calculating MEPpot will allow to determine the thresholds of resistance and resilience and potential tipping points for a regime shift towards irreversible or permanent unfavorable soil states for each individual soil considered. The calculation of such ecosystem thresholds is to our opinion the current global cross-disciplinary challenge. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Soil fauna, soil properties and geo-ecosystem functioning

    NASA Astrophysics Data System (ADS)

    Cammeraat, L. H.

    2012-04-01

    The impact of soil fauna on soil processes is of utmost importance, as the activity of soil fauna directly affects soil quality. This is expressed by the direct effects of soil fauna on soil physical and soil chemical properties that not only have great importance to food production and ecosystems services, but also on weathering and hydrological and geomorphological processes. Soil animals can be perceived as ecosystem engineers that directly affect the flow of water, sediments and nutrients through terrestrial ecosystems. The biodiversity of animals living in the soil is huge and shows a huge range in size, functions and effects. Most work has been focused on only a few species such as earthworms and termites, but in general the knowledge on the effect of soil biota on soil ecosystem functioning is limited as it is for their impact on processes in the soil and on the soil surface. In this presentation we would like to review some of the impacts of soil fauna on soil properties that have implications for geo-ecosystem functioning and soil formation processes.

  15. Physical soil quality indicators for monitoring British soils

    NASA Astrophysics Data System (ADS)

    Corstanje, Ron; Mercer, Theresa G.; Rickson, Jane R.; Deeks, Lynda K.; Newell-Price, Paul; Holman, Ian; Kechavarsi, Cedric; Waine, Toby W.

    2017-09-01

    Soil condition or quality determines its ability to deliver a range of functions that support ecosystem services, human health and wellbeing. The increasing policy imperative to implement successful soil monitoring programmes has resulted in the demand for reliable soil quality indicators (SQIs) for physical, biological and chemical soil properties. The selection of these indicators needs to ensure that they are sensitive and responsive to pressure and change, e.g. they change across space and time in relation to natural perturbations and land management practices. Using a logical sieve approach based on key policy-related soil functions, this research assessed whether physical soil properties can be used to indicate the quality of British soils in terms of their capacity to deliver ecosystem goods and services. The resultant prioritised list of physical SQIs was tested for robustness, spatial and temporal variability, and expected rate of change using statistical analysis and modelling. Seven SQIs were prioritised: soil packing density, soil water retention characteristics, aggregate stability, rate of soil erosion, depth of soil, soil structure (assessed by visual soil evaluation) and soil sealing. These all have direct relevance to current and likely future soil and environmental policy and are appropriate for implementation in soil monitoring programmes.

  16. Soil fauna and soil microflora as possible indicators of soil pollution.

    PubMed

    Eijsackers, H

    1983-09-01

    Research on biological indicators of soil pollution is hampered by soil variability and temporal and spatial fluctuations of numbers of soil animals. These characters on the other hand promote a high biological diversity in the soil. A high diversity combined with persistent soil pollutants increases the chance to select good indicators. However research on these topics is still limited. Examples of specific indicators are the changed arthropod species patterns due to pesticide influence and the changed soil enzyme activity under the influence of specific heavy metals. Another approach is to look for organisms that give a general indication of soil pollution. In this respect the earthworm species Allolobophora caliginosa proved to be sensitive for different types of manure especially pig manure with copper, for sewage sludge, for municipal waste compost and for fly ash. A third way of indication is by organisms accumulating pollutants. For some heavy metals (Cd, Zn), earthworms are very efficient accumulators. More research is needed especially on the specific relation between biological responses and abiotic soil characteristics.

  17. Soils

    Treesearch

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  18. Soil geomorphic classification, soil taxonomy, and effects on soil richness assessments

    Treesearch

    Jonathan D. Phillips; Daniel A. Marion

    2007-01-01

    The study of pedodiversity and soil richness depends on the notion of soils as discrete entities. Soil classifications are often criticized in this regard because they depend in part on arbitrary or subjective criteria. In this study soils were categorized on the basis of the presence or absence of six lithological and morphological characteristics. Richness vs. area...

  19. (abstract) Monitoring the Freeze/Thaw Transitions in Taiga Forests Using ERS-1 SAR

    NASA Technical Reports Server (NTRS)

    Rignot, E.; Williams, C.; Donald, K. Mc; Way, J. B.; Zimmerman, R.; Viereck, L.

    1994-01-01

    Automated recording stations have been installed at the Bonanza Creek Experimental Forest, a Long Term Ecological Research (LTER) site located near Fairbanks, Alaska, in a forest stand of the Tanana River floodplain underlain by discontinuous permafrost. These stations provide a continuous record of dielectric constant and temperature of tree trunks, and soil moisture and temperature profiles down to the root zone. Along with the weather stations deployed at the same location, these measurements provide a continuous record of the environmental and phenologic conditions of the forest during a complete seasonal cycle. At the same time, ERS-1 SAR imaged the study site repeatedly from space to provide radar backscatter measurements of the forest approximately three times a month. Here, we examine the temporal dynamic of ERS-1 SAR measurements in relation with the changing environmental and phenologic state of the forest canopy and of the forest ground layers during the winter/spring and fall/winter transitions of 1992 and 1993. During these transitions, we examine whether changes in radar backscatter observed by ERS-1 may be related to freezing or thawing of the soil and vegetation in order to determine the start and end of the growing season for the forest. The results of this analysis are used in turn to determine whether similar changes are observed over larger regions. Mosaics of SAR data generated along three different North-South Alaskan ERS-1 transects that intercept with our study site are used in combination with hourly air temperature and daily precipitation rates gathered at airport weather stations by the National Weather Service. Results obtained using ERS-1 data collected from January 1992 to mid-1993 will be discussed.

  20. Lunar soil properties and soil mechanics

    NASA Technical Reports Server (NTRS)

    Mitchell, J. K.; Houston, W. N.; Hovland, H. J.

    1972-01-01

    The study to identify and define recognizable fabrics in lunar soil in order to determine the history of the lunar regolith in different locations is reported. The fabric of simulated lunar soil, and lunar soil samples are discussed along with the behavior of simulated lunar soil under dynamic and static loading. The planned research is also included.

  1. Effects of long-term soil and crop management on soil hydraulic properties for claypan soils

    USDA-ARS?s Scientific Manuscript database

    Regional and national soil maps have been developed along with associated soil property databases to assist users in making land management decisions based on soil characteristics. These soil properties include average values from soil characterization for each soil series. In reality, these propert...

  2. Isolation and identification of soil fungi isolates from forest soil for flooded soil recovery

    NASA Astrophysics Data System (ADS)

    Hazwani Aziz, Nor; Zainol, Norazwina

    2018-04-01

    Soil fungi have been evaluated for their ability in increasing and recovering nitrogen, phosphorus and potassium content in flooded soil and in promoting the growth of the host plant. Host plant was cultivated in a mixture of fertile forest soil (nutrient-rich soil) and simulated flooded soil (nutrient-poor soil) in an optimized soil condition for two weeks. The soil sample was harvested every day until two weeks of planting and was tested for nitrogen, phosphorus and potassium concentration. Soil fungi were isolated by using dilution plating technique and was identified by Biolog’s Microbial Systems. The concentration of nitrogen, phosphorus, and potassium was found to be increasing after two weeks by two to three times approximately from the initial concentration recorded. Two fungi species were identified with probability more than 90% namely Aspergillus aculeatus and Paecilomyces lilacinus. Both identified fungi were found to be beneficial in enhancing plant growth and increasing the availability of nutrient content in the soil and thus recovering the nutrient content in the flooded soil.

  3. Radiocarbon ages of terrestrial gastropods extend duration of ice-free conditions at the Two Creeks forest bed, Wisconsin, USA

    USGS Publications Warehouse

    Rech, Jason A.; Nekola, Jeffrey C.; Pigati, Jeffrey S.

    2012-01-01

    Analysis of terrestrial gastropods that underlie the late Pleistocene Two Creeks forest bed (~ 13,800–13,500 cal yr BP) in eastern Wisconsin, USA provides evidence for a mixed tundra-taiga environment prior to formation of the taiga forest bed. Ten new AMS 14C analyses on terrestrial gastropod shells indicate the mixed tundra-taiga environment persisted from ~ 14,500 to 13,900 cal yr BP. The Twocreekan climatic substage, representing ice-free conditions on the shore of Lake Michigan, therefore began near the onset of peak warming conditions during the Bølling–Allerød interstadial and lasted ~ 1000 yr, nearly 600 yr longer than previously thought. These results provide important data for understanding the response of continental ice sheets to global climate forcing and demonstrate the potential of using terrestrial gastropod fossils for both environmental reconstruction and age control in late Quaternary sediments.

  4. Soil forensics: How far can soil clay analysis distinguish between soil vestiges?

    PubMed

    Corrêa, R S; Melo, V F; Abreu, G G F; Sousa, M H; Chaker, J A; Gomes, J A

    2018-03-01

    Soil traces are useful as forensic evidences because they frequently adhere to individuals and objects associated with crimes and can place or discard a suspect at/from a crime scene. Soil is a mixture of organic and inorganic components and among them soil clay contains signatures that make it reliable as forensic evidence. In this study, we hypothesized that soils can be forensically distinguished through the analysis of their clay fraction alone, and that samples of the same soil type can be consistently distinguished according to the distance they were collected from each other. To test these hypotheses 16 Oxisol samples were collected at distances of between 2m and 1.000m, and 16 Inceptisol samples were collected at distances of between 2m and 300m from each other. Clay fractions were extracted from soil samples and analyzed for hyperspectral color reflectance (HSI), X-ray diffraction crystallographic (XRD), and for contents of iron oxides, kaolinite and gibbsite. The dataset was submitted to multivariate analysis and results were from 65% to 100% effective to distinguish between samples from the two soil types. Both soil types could be consistently distinguished for forensic purposes according to the distance that samples were collected from each other: 1000m for Oxisol and 10m for Inceptisol. Clay color and XRD analysis were the most effective techniques to distinguish clay samples, and Inceptisol samples were more easily distinguished than Oxisol samples. Soil forensics seems a promising field for soil scientists as soil clay can be useful as forensic evidence by using routine analytical techniques from soil science. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

  5. Enzymatic activities in a semiarid soil amended with different soil treatment: Soil quality improvement

    NASA Astrophysics Data System (ADS)

    Hueso González, Paloma; Elbl, Jakub; Dvořáčková, Helena; Francisco Martinez Murillo, Juan; Damian Ruiz Sinoga, Jose

    2017-04-01

    The use of soil quality indicators may be an effective approach to assess the positive effect of the organic amendment as good restoration methods. Relying on the natural fertility of the soil, the most commonly chemical and physical parameters used to evaluate soil quality are depend to the soil biological parameters. The measurement of soil basal respiration and the mineralization of organic matter are commonly accepted as a key indicator for measuring changes to soil quality. Thus, the simultaneous measurement of various enzymes seems to be useful to evaluate soil biochemical activity and related processes. In this line, Dehydrogenase activity is widely used in evaluating the metabolic activity of soil microorganisms and to evaluate the effects caused by the addition of organic amendments. Variations in phosphatase activity, apart from indicating changes in the quantity and quality of soil phosphorated substrates, are also good indicators of soil biological status. This study assesses the effect of five soil amendments as restoration techniques for semiarid Mediterrenean ecosystems. The goal is to interpret the status of biological and chemical parameters in each treatment as soil quality indicators in degraded forests. The main objectives were to: i) analyze the effect of various organic amendments on the enzimatic activity of soil; ii) analyze the effect of the amendments on soil respiration; iii) assess the effect of these parameters on the soil chemical properties which are indicative of soil healthy; and iv) evaluated form the land management point of view which amendment could result a effective method to restore Mediterranean degraded areas. An experimental paired-plot layout was established in southern of Spain (homogeneous slope gradient: 7.5%; aspect: N170). Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis Mill.); TerraCotten hydroabsobent polymers; sewage

  6. Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties.

    PubMed

    Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile

    2015-11-01

    The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Delineation of colluvial soils in different soil regions

    NASA Astrophysics Data System (ADS)

    Zádorová, Tereza; Penížek, Vít; Vašát, Radim

    2015-04-01

    Colluvial soils are considered to be the direct result of accelerated soil erosion in agricultural landscape, resulting in accumulation of humus-rich soil material in terrain depressions and toe slopes. They represent an important soil cover element in landscapes influenced by soil erosion and form an important soil organic carbon (SOC) pool. Delineation of colluvial soils can identify areas with high sediment input and potential deep organic carbon storage and thus improve our knowledge on soil mass and SOC stock redistribution in dissected landscapes. Different prediction methods (ordinary kriging, multiple linear regression, supervised fuzzy classification, artificial neural network, support vector machines) for colluvial soils delineation have been tested in three different soil regions (Cambisol, Luvisol and Chernozem) at two scales (plot and watershed) in the Czech Republic. The approach is based on exploitation of relationship between soil and terrain units and assumes that colluvial soil can be defined by particular range of terrain attributes values. Terrain attributes derived from precise DEMs were used as predictors in applied models. The soil-terrain relationship was assessed using a large dataset of field investigations (300 cores at each plot and 100 cores at each watershed). Models were trained at plot scale (15-33 ha) and the best performing model was then calibrated and validated at watershed scale (25-55 km2). The study proved high potential of terrain variables as predictors in colluvial soil delineation. Support vector machines method was the best performing method for colluvial soil occurrence prediction at all the three sites. However, significant differences in performance have been identified among the studied plots. The best results were obtained in Luvisol region where both determination coefficient and prediction accuracy reached the highest values. The model performance was satisfactory also in Chernozem region. The model showed its

  8. Diel hysteresis between soil respiration and soil temperature in a biological soil crust covered desert ecosystem

    PubMed Central

    Li, Xinrong; Zhang, Peng; Chen, Yongle

    2018-01-01

    Soil respiration induced by biological soil crusts (BSCs) is an important process in the carbon (C) cycle in arid and semi-arid ecosystems, where vascular plants are restricted by the harsh environment, particularly the limited soil moisture. However, the interaction between temperature and soil respiration remains uncertain because of the number of factors that control soil respiration, including temperature and soil moisture, especially in BSC-dominated areas. In this study, the soil respiration in moss-dominated crusts and lichen-dominated crusts was continuously measured using an automated soil respiration system over a one-year period from November 2015 to October 2016 in the Shapotou region of the Tengger Desert, northern China. The results indicated that over daily cycles, the half-hourly soil respiration rates in both types of BSC-covered areas were commonly related to the soil temperature. The observed diel hysteresis between the half-hourly soil respiration rates and soil temperature in the BSC-covered areas was limited by nonlinearity loops with semielliptical shapes, and soil temperature often peaked later than the half-hourly soil respiration rates in the BSC-covered areas. The average lag times between the half-hourly soil respiration rates and soil temperature for both types of BSC-covered areas were two hours over the diel cycles, and they were negatively and linearly related to the volumetric soil water content. Our results highlight the diel hysteresis phenomenon that occurs between soil respiration rates and soil temperatures in BSC-covered areas and the negative response of this phenomenon to soil moisture, which may influence total C budget evaluations. Therefore, the interactive effects of soil temperature and moisture on soil respiration in BSC-covered areas should be considered in global carbon cycle models of desert ecosystems. PMID:29624606

  9. Should soil testing services measure soil biological activity

    USDA-ARS?s Scientific Manuscript database

    Health of agricultural soils depends largely on conservation management to promote soil organic C accumulation. Total soil organic C changes slowly, but active fractions are more dynamic. A key indicator of healthy soil is potential biological activity, which could be measured rapidly with soil te...

  10. Comparing organic versus conventional soil management on soil respiration.

    PubMed

    Mátyás, Bence; Chiluisa Andrade, Maritza Elizabeth; Yandun Chida, Nora Carmen; Taipe Velasco, Carina Maribel; Gavilanes Morales, Denisse Estefania; Miño Montero, Gisella Nicole; Ramirez Cando, Lenin Javier; Lizano Acevedo, Ronnie Xavier

    2018-01-01

    Soil management has great potential to affect soil respiration. In this study, we investigated the effects of organic versus conventional soil management on soil respiration.  We measured the main soil physical-chemical properties from conventional and organic managed soil in Ecuador. Soil respiration was determined using alkaline absorption according to Witkamp.  Soil properties such as organic matter, nitrogen, and humidity, were comparable between conventional and organic soils in the present study, and in a further analysis there was no statically significant correlation with soil respiration. Therefore, even though organic farmers tend to apply more organic material to their fields, but this did not result in a significantly higher CO2 production in their soils in the present study.

  11. Comparing organic versus conventional soil management on soil respiration

    PubMed Central

    Mátyás, Bence; Chiluisa Andrade, Maritza Elizabeth; Yandun Chida, Nora Carmen; Taipe Velasco, Carina Maribel; Gavilanes Morales, Denisse Estefania; Miño Montero, Gisella Nicole; Ramirez Cando, Lenin Javier; Lizano Acevedo, Ronnie Xavier

    2018-01-01

    Soil management has great potential to affect soil respiration. In this study, we investigated the effects of organic versus conventional soil management on soil respiration.  We measured the main soil physical-chemical properties from conventional and organic managed soil in Ecuador. Soil respiration was determined using alkaline absorption according to Witkamp.  Soil properties such as organic matter, nitrogen, and humidity, were comparable between conventional and organic soils in the present study, and in a further analysis there was no statically significant correlation with soil respiration. Therefore, even though organic farmers tend to apply more organic material to their fields, but this did not result in a significantly higher CO2 production in their soils in the present study. PMID:29623193

  12. Working with Soil - Soil science in the field

    NASA Astrophysics Data System (ADS)

    Hannam, Jacqueline; Lacelles, Bruce; Owen, Jason; Thompson, Dick; Jones, Bob; Towers, Willie

    2015-04-01

    Working with Soil is the Professional Competency Scheme developed by the British Society of Soil Science's Professional Practice Committee, formerly the Institute of Professional Soil Scientists. Ten competency documents cover the required qualifications, skills and knowledge for different aspects of applied soil science. The Society is currently engaged in a five year plan to translate the competency documents into a comprehensive set of training courses. Foundation skills in field-based science are covered by three separate training courses - Exposing and describing a soil profile (Course 1), Soil classification (Course 2), and Soil survey techniques (Course 3). Course 1 has run successfully twice a year since 2013. The other two courses are under development and are scheduled to start in 2015. The primary objective of Foundation Skills Course 1 is to develop confidence and familiarity with field soil investigation and description, understanding the soil underfoot and putting soils into a wider landscape context. Delegates excavate a soil profile pit, and describe and sample the exposed soil to standard protocols. Delegates work in teams of 4 or 5 so that an element of shared learning is part of the process. This has been a very positive aspect of the courses we have run to date. The course has attracted professionals from agricultural and environmental consultancies but is also very popular with research students and has formed a part of an Advanced Training Programme in Soil Science for postgraduates. As there is only one soil science degree course remaining in the UK, many students on their admission do not have a background in field-based pedology and lack an understanding of soil in the context of landscape scale soil functions. Feedback to date has been very positive.

  13. Development of soil taxation and soil classification as furthered by the Austrian Soil Science Society

    NASA Astrophysics Data System (ADS)

    Baumgarten, Andreas

    2013-04-01

    Soil taxation and soil classification are important drivers of soil science in Austria. However, the tasks are quite different: whereas soil taxation aims at the evaluation of the productivity potential of the soil, soil classification focusses on the natural development and - especially nowadays - on functionality of the soil. Since the foundation of the Austrian Soil Science Society (ASSS), representatives both directions of the description of the soil have been involved in the common actions of the society. In the first years it was a main target to improve and standardize field descriptions of the soil. Although both systems differ in the general layout, the experts should comply with identical approaches. According to this work, a lot of effort has been put into the standardization of the soil classification system, thus ensuring a common basis. The development, state of the art and further development of both classification and taxation systems initiated and carried out by the ASSS will be shown.

  14. SOIL Geo-Wiki: A tool for improving soil information

    NASA Astrophysics Data System (ADS)

    Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

    2014-05-01

    Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference

  15. Soil vital signs: A new Soil Quality Index (SQI) for assessing forest soil health

    Treesearch

    Michael C. Amacher; Katherine P. O' Neil; Charles H. Perry

    2007-01-01

    The Forest Inventory and Analysis (FIA) program measures a number of chemical and physical properties of soils to address specific questions about forest soil quality or health. We developed a new index of forest soil health, the soil quality index (SQI), that integrates 19 measured physical and chemical properties of forest soils into a single number that serves as...

  16. The Soil Series in Soil Classifications of the United States

    NASA Astrophysics Data System (ADS)

    Indorante, Samuel; Beaudette, Dylan; Brevik, Eric C.

    2014-05-01

    Organized national soil survey began in the United States in 1899, with soil types as the units being mapped. The soil series concept was introduced into the U.S. soil survey in 1903 as a way to relate soils being mapped in one area to the soils of other areas. The original concept of a soil series was all soil types formed in the same parent materials that were of the same geologic age. However, within about 15 years soil series became the primary units being mapped in U.S. soil survey. Soil types became subdivisions of soil series, with the subdivisions based on changes in texture. As the soil series became the primary mapping unit the concept of what a soil series was also changed. Instead of being based on parent materials and geologic age, the soil series of the 1920s was based on the morphology and composition of the soil profile. Another major change in the concept of soil series occurred when U.S. Soil Taxonomy was released in 1975. Under Soil Taxonomy, the soil series subdivisions were based on the uses the soils might be put to, particularly their agricultural uses (Simonson, 1997). While the concept of the soil series has changed over the years, the term soil series has been the longest-lived term in U.S. soil classification. It has appeared in every official classification system used by the U.S. soil survey (Brevik and Hartemink, 2013). The first classification system was put together by Milton Whitney in 1909 and had soil series at its second lowest level, with soil type at the lowest level. The second classification system used by the U.S. soil survey was developed by C.F. Marbut, H.H. Bennett, J.E. Lapham, and M.H. Lapham in 1913. It had soil series at the second highest level, with soil classes and soil types at more detailed levels. This was followed by another system in 1938 developed by M. Baldwin, C.E. Kellogg, and J. Thorp. In this system soil series were again at the second lowest level with soil types at the lowest level. The soil type

  17. Soil management: The key to soil quality and sustainable agriculture

    NASA Astrophysics Data System (ADS)

    Basch, Gottlieb; Barão, Lúcia; Soares, Miguel

    2017-04-01

    Today, after the International Year of Soils in 2015 and the proclamation by the International Union of Soil Sciences of the International Decade of Soils 2015-2020, much attention is paid to soil quality. Often used interchangeably, both terms, soil quality and soil health, refer to dynamic soil properties such as soil organic matter or pH, while soil quality also includes inherent soil properties such as texture or mineral composition. However, it is the dynamic or manageable properties that adequate soil management can influence and thus contribute to a well-functioning soil environment capable to deliver the soil-mediated provisioning, regulating and supporting ecosystem services and soil functions. This contribution intends to highlight the key principles of sustainable soil management and provide evidence that they are compliant with a productive, resource efficient and ecologically friendly agriculture. Paradoxically, and despite benefitting from good soil quality, agriculture itself when based on conventional, especially intensive tillage-based soil management practices contributes decisively to soil degradation and to several of the soil threats as identified by the Soil Thematic Strategy, being soil erosion and soil organic matter decline the most notorious ones. To mitigate soil degradation, the European Union's Common Agricultural Policy has introduced conservation measures, mainly through cross-compliance measures supposed to guarantee minimum soil cover, to limit soil erosion and to maintain the levels of soil organic matter. However, it remains unclear to what extent EU member states apply these 'Good Agricultural and Environmental Condition' (GAEC) measures to their utilized agricultural areas. Effective and cost-efficient soil management systems able to conserve or to restore favourable soil conditions, to minimize soil erosion and to invert soil organic matter and soil biodiversity decline and improve soil structure are those capable to mimic as

  18. Forest soils

    Treesearch

    Charles H. (Hobie) Perry; Michael C. Amacher

    2009-01-01

    Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

  19. Enhancing soil begins with soil biology and a stable soil microclimate

    USDA-ARS?s Scientific Manuscript database

    Protection of the soil resource from erosion requires reducing the surface impact from raindrop energy and maintaining soil structure and stability to allow more efficient infiltration of water into the soil column. These two processes are linked with practices associated with enhancing and maintain...

  20. Effects of Long-term Soil and Crop Management on Soil Hydraulic Properties for Claypan Soils

    USDA-ARS?s Scientific Manuscript database

    Regional and national soil maps and associated databases of soil properties have been developed to help land managers make decisions based on soil characteristics. Hydrologic modelers also utilize soil hydraulic properties provided in these databases, in which soil characterization is based on avera...

  1. Soil structural quality assessment for soil protection regulation

    NASA Astrophysics Data System (ADS)

    Johannes, Alice; Boivin, Pascal

    2017-04-01

    Soil quality assessment is rapidly developing worldwide, though mostly focused on the monitoring of arable land and soil fertility. Soil protection regulations assess soil quality differently, focusing on priority pollutants and threshold values. The soil physical properties are weakly considered, due to lack of consensus and experimental difficulties faced with characterization. Non-disputable, easy to perform and inexpensive methods should be available for environmental regulation to be applied, which is unfortunately not the case. As a consequence, quantitative soil physical protection regulation is not applied, and inexpensive soil physical quality indicators for arable soil management are not available. Overcoming these limitations was the objective of a research project funded by the Swiss federal office for environment (FOEN). The main results and the perspectives of application are given in this presentation. A first step of the research was to characterize soils in a good structural state (reference soils) under different land use. The structural quality was assessed with field expertise and Visual Evaluation of the Soil Structure (VESS), and the physical properties were assessed with Shrinkage analysis. The relationships between the physical properties and the soil constituents were linear and highly determined. They represent the reference properties of the corresponding soils. In a second step, the properties of physically degraded soils were analysed and compared to the reference properties. This allowed defining the most discriminant parameters departing the different structure qualities and their threshold limits. Equivalent properties corresponding to these parameters but inexpensive and easy to determine were defined and tested. More than 90% of the samples were correctly classed with this method, which meets, therefore, the requirements for practical application in regulation. Moreover, result-oriented agri-environmental schemes for soil quality

  2. [Microscopic soil fungi - bioindicators organisms contaminated soil].

    PubMed

    Donerian, L G; Vodianova, M A; Tarasova, Zh E

    In the paper there are considered methodological issues for the evaluation of soil biota in terms of oil pollution. Experimental studies have shown that under the exposure of a various levels of oil pollution meeting certain gradations of the state and optimal alteration in microbocenosis in sod-podzolic soils, there is occurred a transformation of structure of the complex of micromycetes and the accumulation of toxic species, hardly typical for podzolic soils - primarily represantatives of the genus Aspergillus (A.niger and A. versicolor), Paecilomyces (P.variotii Bainer), Trichoderma (T.hamatum), the genus of phytopathogens Fusarium (F.oxysporum), dermatophytes of genus Sporothrix (S. schenckii) and dark-colored melanin containing fungi of Dematiaceae family. Besides that there are presented data on the study of microbiocenosis of the urban soil, the urban soil differed from the zone soil, but shaped in similar landscape and climatic conditions, and therefore having a tendency to a similar response from the side of microorganisms inhabiting the soil. Isolated complex of soil microscopic fungi is described by many authors as a complex, characteristic for soils of megalopolises. This allowed authors of this work to suggest that in urban soils the gain in the occurrence of pathogenic species micromycetes also increases against a background of chronic, continuously renewed inflow of petroleum hydrocarbons from various sources of pollution. Because changes in the species composition of micromycetes occurred in accordance with the increasing load of oil, so far as microscopic soil fungi can be recommended as a bioindicator organisms for oil. In the article there is also provided information about the distinctive features of modern DNA identification method of soil microscopic fungi and accepted in our country methodology of isolation of micromycetes with the use of a nutrient Czapek medium.

  3. SoilInfo App: global soil information on your palm

    NASA Astrophysics Data System (ADS)

    Hengl, Tomislav; Mendes de Jesus, Jorge

    2015-04-01

    ISRIC ' World Soil Information has released in 2014 and app for mobile de- vices called 'SoilInfo' (http://soilinfo-app.org) and which aims at providing free access to the global soil data. SoilInfo App (available for Android v.4.0 Ice Cream Sandwhich or higher, and Apple v.6.x and v.7.x iOS) currently serves the Soil- Grids1km data ' a stack of soil property and class maps at six standard depths at a resolution of 1 km (30 arc second) predicted using automated geostatistical mapping and global soil data models. The list of served soil data includes: soil organic carbon (), soil pH, sand, silt and clay fractions (%), bulk density (kg/m3), cation exchange capacity of the fine earth fraction (cmol+/kg), coarse fragments (%), World Reference Base soil groups, and USDA Soil Taxonomy suborders (DOI: 10.1371/journal.pone.0105992). New soil properties and classes will be continuously added to the system. SoilGrids1km are available for download under a Creative Commons non-commercial license via http://soilgrids.org. They are also accessible via a Representational State Transfer API (http://rest.soilgrids.org) service. SoilInfo App mimics common weather apps, but is also largely inspired by the crowdsourcing systems such as the OpenStreetMap, Geo-wiki and similar. Two development aspects of the SoilInfo App and SoilGrids are constantly being worked on: Data quality in terms of accuracy of spatial predictions and derived information, and Data usability in terms of ease of access and ease of use (i.e. flexibility of the cyberinfrastructure / functionalities such as the REST SoilGrids API, SoilInfo App etc). The development focus in 2015 is on improving the thematic and spatial accuracy of SoilGrids predictions, primarily by using finer resolution covariates (250 m) and machine learning algorithms (such as random forests) to improve spatial predictions.

  4. Shaping an Optimal Soil by Root-Soil Interaction.

    PubMed

    Jin, Kemo; White, Philip J; Whalley, William R; Shen, Jianbo; Shi, Lei

    2017-10-01

    Crop production depends on the availability of water and mineral nutrients, and increased yields might be facilitated by a greater focus on roots-soil interactions. Soil properties affecting plant growth include drought, compaction, nutrient deficiency, mineral toxicity, salinity, and submergence. Plant roots respond to the soil environment both spatially and temporally by avoiding stressful soil environments and proliferating in more favorable environments. We observe that crops can be bred for specific root architectural and biochemical traits that facilitate soil exploration and resource acquisition, enabling greater crop yields. These root traits affect soil physical and chemical properties and might be utilized to improve the soil for subsequent crops. We argue that optimizing root-soil interactions is a prerequisite for future food security. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Should there be a "Wet" Soil Order in Soil Taxonomy?

    NASA Astrophysics Data System (ADS)

    Rabenhorst, Martin; Wessel, Barret; Stolt, Mark; Lindbo, David

    2017-04-01

    Early soil classification systems recognized wet soils at the highest categorical level. Among the Intrazonal Soils of the US classification utilized between the 1920s and 1960, were included as Great Soil Groups, the Wiesenboden, Bog, Half-Bog, Ground-Water Podzols and Ground-Water Laterites. In other systems, groups named with such terms as ground water gley and pseudogley were also used. With the advent of Soil Taxonomy and it's precursor (1960, 1975), Histosols (organic soils) were distinguished as one of the initial 10 soil orders, and while many of these organic soils are wet soils, some are not (Folists for example). Thus, for over 50 years, with the exception of Histosols, wet soils (which typically represent the wettest end of subaerial wet soils) have not been collectively recognized within taxa at the highest categorical level (order) in the US soil classification system. Rather, the wettest soils were designated at the second categorical level as wet (Aqu) suborders among the various soil orders, and more recently, subaqueous soils as "Wass" suborders of Entisols and Histosols. Soils with less-wet conditions have been recognized at the subgroup (4th) level. Further, in impoundments and regions of transgressing coastlines, submerged upland soils have been found that still classify in soil orders that do not accommodate subaqueous soils ("Wass" suborders). Notwithstanding, other contemporary soil classification systems do (have continued to) recognize wet soils at the highest level. In the World Reference Base (WRB) for example, wet soils are designated as Gleysols or Stagnosols. As efforts are underway to revisit, simplify, and revise Soil Taxonomy, questions have been raised regarding whether wet soils should again be moved back with a place among taxa at the highest category using a name such as Hydrasols, Aquasols, etc. This paper will explore and consider the questions and arguments for and against such proposals and the difficult question regarding

  6. Soil organic matter as sole indicator of soil degradation.

    PubMed

    Obalum, S E; Chibuike, G U; Peth, S; Ouyang, Y

    2017-04-01

    Soil organic matter (SOM) is known to play vital roles in the maintenance and improvement of many soil properties and processes. These roles, which largely influence soil functions, are a pool of specific contributions of different components of SOM. The soil functions, in turn, normally define the level of soil degradation, viewed as quantifiable temporal changes in a soil that impairs its quality. This paper aims at providing a generalized assessment of the current state of knowledge on the usefulness of SOM in monitoring soil degradation, based on its influence on the physical, chemical and biological properties and processes of soils. Emphasis is placed particularly on the effect of SOM on soil structure and availability of plant nutrients. Although these properties are discussed separately, the soil system is of dynamic and interactive nature, and changes in one property will likely affect other soil properties as well. Thus, functions of SOM almost always affect various soil properties and processes and engage in multiple reactions. In view of its role in soil aggregation and erosion control, in availability of plant nutrients and in ameliorating other forms of soil degradation than erosion, SOM has proven to be an important indicator of soil degradation. It has been suggested, however, that rather than the absolute amount, temporal change and potential amount of SOM be considered in its use as indicator of soil degradation, and that SOM may not be an all-purpose indicator. Whilst SOM remains a candidate without substitute as long as a one-parameter indicator of soil degradation is needed, narrowing down to the use of its labile and microbial components could be more appropriate, since early detection is important in the control and management of soil degradation.

  7. Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material

    USGS Publications Warehouse

    Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R.

    2013-01-01

    Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0–1 cm; below-crust soils, 2–5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

  8. Estimation of soil-soil solution distribution coefficient of radiostrontium using soil properties.

    PubMed

    Ishikawa, Nao K; Uchida, Shigeo; Tagami, Keiko

    2009-02-01

    We propose a new approach for estimation of soil-soil solution distribution coefficient (K(d)) of radiostrontium using some selected soil properties. We used 142 Japanese agricultural soil samples (35 Andosol, 25 Cambisol, 77 Fluvisol, and 5 others) for which Sr-K(d) values had been determined by a batch sorption test and listed in our database. Spearman's rank correlation test was carried out to investigate correlations between Sr-K(d) values and soil properties. Electrical conductivity and water soluble Ca had good correlations with Sr-K(d) values for all soil groups. Then, we found a high correlation between the ratio of exchangeable Ca to Ca concentration in water soluble fraction and Sr-K(d) values with correlation coefficient R=0.72. This pointed us toward a relatively easy way to estimate Sr-K(d) values.

  9. Soil tension mediates isotope fractionation during soil water evaporation

    NASA Astrophysics Data System (ADS)

    Gaj, Marcel; McDonnell, Jeffrey

    2017-04-01

    Isotope tracing of the water cycle is increasing in its use and usefulness. Many new studies are extracting soil waters and relating these to streamflow, groundwater recharge and plant transpiration. Nevertheless, unlike isotope fractionation factors from open water bodies, soil water fractionation factors are poorly understood and until now, only empirically derived. In contrast to open water evaporation where temperature, humidity and vapor pressure gradient define fractionation (as codified in the well-known Craig and Gordon model), soil water evaporation includes additionally, fractionation by matrix effects. There is yet no physical explanation of kinetic and equilibrium fraction from soil water within the soil profile. Here we present a simple laboratory experiment with four admixtures of soil grain size (from sand to silt to clay). Oven-dried samples were spiked with water of known isotopic composition at different soil water contents. Soils were then stored in sealed bags and the headspace filled with dry air and allowed to equilibrate for 24hours. Isotopic analysis of the headspace vapor was done with a Los Gatos Inc. water vapor isotope analyzer. Soil water potential of subsamples were measured with a water potential meter. We show for the first time that soil tension controls isotope fractionation in the resident soil water. Below a Pf 3.5 the δ-values of 18O and 2H of the headspace vapor is more positive and increases with increasing soil water potential. Surprisingly, we find that the relationship between soil tension and equilibrium fractionation is independent of soil type. However, δ-values of each soil type plot along a distinct evaporation line. These results indicate that equilibrium fractionation is affected by soil tension in addition to temperature. Therefore, at high soil water tension (under dry conditions) equilibrium fractionation is not consistent with current empirical formulations that ignore these effects. These findings may have

  10. Quantitative assessment on soil enzyme activities of heavy metal contaminated soils with various soil properties.

    PubMed

    Xian, Yu; Wang, Meie; Chen, Weiping

    2015-11-01

    Soil enzyme activities are greatly influenced by soil properties and could be significant indicators of heavy metal toxicity in soil for bioavailability assessment. Two groups of experiments were conducted to determine the joint effects of heavy metals and soil properties on soil enzyme activities. Results showed that arylsulfatase was the most sensitive soil enzyme and could be used as an indicator to study the enzymatic toxicity of heavy metals under various soil properties. Soil organic matter (SOM) was the dominant factor affecting the activity of arylsulfatase in soil. A quantitative model was derived to predict the changes of arylsulfatase activity with SOM content. When the soil organic matter content was less than the critical point A (1.05% in our study), the arylsulfatase activity dropped rapidly. When the soil organic matter content was greater than the critical point A, the arylsulfatase activity gradually rose to higher levels showing that instead of harm the soil microbial activities were enhanced. The SOM content needs to be over the critical point B (2.42% in our study) to protect its microbial community from harm due to the severe Pb pollution (500mgkg(-1) in our study). The quantitative model revealed the pattern of variation of enzymatic toxicity due to heavy metals under various SOM contents. The applicability of the model under wider soil properties need to be tested. The model however may provide a methodological basis for ecological risk assessment of heavy metals in soil. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Soil CO₂ dynamics in a tree island soil of the Pantanal: the role of soil water potential.

    PubMed

    Johnson, Mark S; Couto, Eduardo Guimarães; Pinto, Osvaldo B; Milesi, Juliana; Santos Amorim, Ricardo S; Messias, Indira A M; Biudes, Marcelo Sacardi

    2013-01-01

    The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO₂ research has been conducted in this region. We evaluated soil CO₂ dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed using the gradient method using in situ infrared gas analyzers to directly measure CO₂ concentration within the soil profile. Due to the cost of the sensors and associated equipment, this study was unreplicated. Rather, we focus on the temporal relationships between soil CO₂ efflux and related environmental parameters. Soil CO₂ efflux during the study averaged 3.53 µmol CO₂ m⁻² s⁻¹, and was equivalent to an annual soil respiration of 1220 g C m⁻² y⁻¹. This efflux value, integrated over a year, is comparable to soil C stocks for 0-20 cm. Soil water potential was the measured parameter most strongly associated with soil CO₂ concentrations, with high CO₂ values observed only once soil water potential at the 10 cm depth approached zero. This relationship was exhibited across a spectrum of timescales and was found to be significant at a daily timescale across all seasons using conditional nonparametric spectral Granger causality analysis. Hydrology plays a significant role in controlling CO₂ efflux from the tree island soil, with soil CO₂ dynamics differing by wetting mechanism. During the wet-up period, direct precipitation infiltrates soil from above and results in pulses of CO₂ efflux from soil. The annual flood arrives later, and saturates soil from below. While CO₂ concentrations in soil grew very high under both wetting mechanisms, the change in soil CO₂ efflux was only significant when soils were wet from above.

  12. [Ecological characteristics and distribution of the mosquito Aedes communis (De Geer, 1776) in the Northwestern part of European Russia].

    PubMed

    Medvedev, S G; Aĭbulatiov, S V; Paniukova, E V

    2010-01-01

    According to recent data, Aedes communis is a polytopic species inhabiting both zonal and intrazonal biotopes. It has a wide Holarctic nemoral-tundra-steppe range, which can be characterized as European-Asiatic-North-American. In the North-West of the European part of Russia, A. communis occurs in early spring and summer, being a monocyclic species. It is distributed everywhere, both in zones of tundra and forest-tundra and in all taiga subzones. Aedes communis is a psychrophilic species, but attacks of its females were recorded under the temperatures from 2.5 to 28 degrees C. The species occurs in biotopes of different types, but in the taiga zone it is distributed mainly in swampy coniferous forests and, particularly, in fir-woods where its quantity is steadily high, amounting to 70% and more of the mosquito females collections. When fir-woods are cut down, A. communis develops in the reservoirs situated in the small-leaved forests forming in taiga after deforestation.

  13. Soil! Get the Scoop - The Soil Science Society of America's International Year of Soils Campaign

    NASA Astrophysics Data System (ADS)

    Lindbo, David L.; Hopmans, Jan; Olson, Carolyn; Fisk, Susan; Chapman, Susan; van Es, Harold

    2015-04-01

    Soils are a finite natural resource and are nonrenewable on a human time scale. Soils are the foundation for food, animal feed, fuel and natural fiber production, the supply of clean water, nutrient cycling and a range of ecosystem functions. The area of fertile soils covering the world's surface is limited and increasingly subject to degradation, poor management and loss to urbanization. Increased awareness of the life-supporting functions of soil is called for if this trend is to be reversed and so enable the levels of food production necessary to meet the demands of population levels predicted for 2050. The Soil Science Society of America is coordinating with the Global Soil Partnership and other organizations around the world to celebrate the 2015 International Year of Soils and raise awareness and promote the sustainability of our limited soil resources. We all have a valuable role in communicating vital information on soils, a life sustaining natural resource. Therefore, we will provide resources to learn about soils and help us tell the story of soils. We will promote IYS on social media by sharing our posts from Facebook and Twitter. Additionally SSSA developed 12 monthly themes that reflect the diverse value of soils to our natural environment and society. Each month has information on the theme, a lesson plan, and other outreach activities. All information is available on a dedicated website www.soil.org/IYS. The site will be updated constantly throughout the year.

  14. Impact of Soil Texture on Soil Ciliate Communities

    NASA Astrophysics Data System (ADS)

    Chau, J. F.; Brown, S.; Habtom, E.; Brinson, F.; Epps, M.; Scott, R.

    2014-12-01

    Soil water content and connectivity strongly influence microbial activities in soil, controlling access to nutrients and electron acceptors, and mediating interactions between microbes within and between trophic levels. These interactions occur at or below the pore scale, and are influenced by soil texture and structure, which determine the microscale architecture of soil pores. Soil protozoa are relatively understudied, especially given the strong control they exert on bacterial communities through predation. Here, ciliate communities in soils of contrasting textures were investigated. Two ciliate-specific primer sets targeting the 18S rRNA gene were used to amplify DNA extracted from eight soil samples collected from Sumter National Forest in western South Carolina. Primer sets 121F-384F-1147R (semi-nested) and 315F-959R were used to amplify soil ciliate DNA via polymerase chain reaction (PCR), and the resulting PCR products were analyzed by gel electrophoresis to obtain quantity and band size. Approximately two hundred ciliate 18S rRNA sequences were obtained were obtained from each of two contrasting soils. Sequences were aligned against the NCBI GenBank database for identification, and the taxonomic classification of best-matched sequences was determined. The ultimate goal of the work is to quantify changes in the ciliate community under short-timescale changes in hydrologic conditions for varying soil textures, elucidating dynamic responses to desiccation stress in major soil ciliate taxa.

  15. Working with soils: soil science continuing professional development

    NASA Astrophysics Data System (ADS)

    Hannam, Jacqueline; Thompson, Dick

    2017-04-01

    The British Society of Soil Science launched the Working with Soils professional competency programme in 2011. This was in response to concerns from practitioners and professionals of a significant skills gap in various sectors that require soil science skills. The programme includes one and two day courses that cover the qualifications, knowledge and skills required of a professional scientist or engineer conducting a range of contract work. All courses qualify for continuing professional development points with various professional practice schemes. Three courses cover the foundations of soil science namely; describing a soil profile, soil classification and understanding soil variability in the field and landscape. Other tailored courses relate to specific skills required from consultants particularly in the planning process where land is assessed for agricultural quality (agricultural land classification). New courses this year include soil handling and restoration that provides practitioners with knowledge of the appropriate management of large volumes of soil that are disturbed during development projects. The courses have so far successfully trained over 100 delegates ranging from PhD students, environmental consultants and government policy advisors.

  16. Soil organic matter and soil biodiversity spots in urban and semi urban soils of southeast Mexico

    NASA Astrophysics Data System (ADS)

    Huerta, Esperanza

    2015-04-01

    We have observed how the constant use of compost or vermicompost has created spots of soil restoration in urban and semiurban soils of Chiapas (Huitepec and Teopisca), increasing soil organic matter amount, soil moisture and soil porosity, and enhancing then the presence of soil biodiversity; for example, in a Milpa with vermicompost (polyculture of Zea mays with Curcubita pepo, and Fasolius vulgaris) we have found a high density of an epigeic earthworm (640 ind.m2), Dichogaster bolahui, not present in the same type of soil just some meters of distance, in an Oak forest, where soil macroinvertebrates abundance decreased drastically. In another ecosystem within a Persea Americana culture, we found how above and below ground soil biodiversity is affected by the use of vermicompost, having clearly different microcosmos with and without vermicompost (30-50% more micro and macro invertebrates with vermicompost). So now in Campeche, within those soils that are classified by the mayas as tzequel, soils not use for agriculture, we have implemented home gardens and school gardens by the use of compost of vermicomposts in urban and semiurban soils. In school gardens (mainly primary schools) students have cultivated several plants with alimentary purposes; teachers have observed how the increase of soil biodiversity by the use of compost or vermicompost has enhanced the curiosity of children, even has promoted a more friendly behavior among students, they have learned how to do compost and how to apply it. Urban and semiurban soils can be modified by the use of compost and vermicompost, and soil biodiversity has extremely increased.

  17. Anaerobic soil disinfestation and soil borne pest management

    USDA-ARS?s Scientific Manuscript database

    Anaerobic soil disinfestation (ASD; also referred to as Biological Soil Disinfestation (BSD)) is a pre-plant soil treatment method developed to control plant disease and manage yield decline in many crop production systems. The practice involves induction of anaerobic soil conditions by increasing m...

  18. Soil warming increases metabolic quotients of soil microorganisms without changes in temperature sensitivity of soil respiration

    NASA Astrophysics Data System (ADS)

    Marañón-Jiménez, Sara; Soong, Jenniffer L.; Leblans, Niki I. W.; Sigurdsson, Bjarni D.; Dauwe, Steven; Fransen, Erik; Janssens, Ivan A.

    2017-04-01

    Increasing temperatures can accelerate soil organic matter (SOM) decomposition and release large amounts of CO2 to the atmosphere, potentially inducing climate change feedbacks. Alterations to the temperature sensitivity and metabolic pathways of soil microorganisms in response to soil warming can play a key role in these soil carbon (C) losses. Here, we present results of an incubation experiment using soils from a geothermal gradient in Iceland that have been subjected to different intensities of soil warming (+0, +1, +3, +5, +10 and +20 °C above ambient) over seven years. We hypothesized that 7 years of soil warming would led to a depletion of labile organic substrates, with a subsequent decrease of the "apparent" temperature sensitivity of soil respiration. Associated to this C limitation and more sub-optimal conditions for microbial growth, we also hypothesized increased microbial metabolic quotients (soil respiration per unit of microbial biomass), which is associated with increases in the relative amount of C invested into catabolic pathways along the warming gradient. Soil respiration and basal respiration rates decreased with soil warming intensity, in parallel with a decline in soil C availability. Contrasting to our first hypothesis, we did not detect changes in the temperature sensitivity of soil respiration with soil warming or on the availability of nutrients and of labile C substrates at the time of incubation. However, in agreement to our second hypothesis, microbial metabolic quotients (soil respiration per unit of microbial biomass) increased at warmer temperatures, while the C retained in biomass decreased as substrate became limiting. Long-term (7 years) temperature increases thus triggered a change in the metabolic functioning of the soil microbial communities towards increasing energy costs for maintenance or resource acquisition, thereby lowering the capacity of C retention and stabilization of warmed soils. These results highlight the need

  19. Soil salinity decreases global soil organic carbon stocks.

    PubMed

    Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

    2013-11-01

    Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Soil functional types: surveying the biophysical dimensions of soil security

    NASA Astrophysics Data System (ADS)

    Cécillon, Lauric; Barré, Pierre

    2015-04-01

    Soil is a natural capital that can deliver key ecosystem services (ES) to humans through the realization of a series of soil processes controlling ecosystem functioning. Soil is also a diverse and endangered natural resource. A huge pedodiversity has been described at all scales, which is strongly altered by global change. The multidimensional concept soil security, encompassing biophysical, economic, social, policy and legal frameworks of soils has recently been proposed, recognizing the role of soils in global environmental sustainability challenges. The biophysical dimensions of soil security focus on the functionality of a given soil that can be viewed as the combination of its capability and its condition [1]. Indeed, all soils are not equal in term of functionality. They show different processes, provide different ES to humans and respond specifically to global change. Knowledge of soil functionality in space and time is thus a crucial step towards the achievement soil security. All soil classification systems incorporate some functional information, but soil taxonomy alone cannot fully describe the functioning, limitations, resistance and resilience of soils. Droogers and Bouma [2] introduced functional variants (phenoforms) for each soil type (genoform) so as to fit more closely to soil functionality. However, different genoforms can have the same functionality. As stated by McBratney and colleagues [1], there is a great need of an agreed methodology for defining the reference state of soil functionality. Here, we propose soil functional types (SFT) as a relevant classification system for the biophysical dimensions of soil security. Following the definition of plant functional types widely used in ecology, we define a soil functional type as "a set of soil taxons or phenoforms sharing similar processes (e.g. soil respiration), similar effects on ecosystem functioning (e.g. primary productivity) and similar responses to global change (land-use, management or

  1. ANAEROBIC SOIL DISINFESTATION IN MICROCOSMS OF TWO SANDY SOILS.

    PubMed

    Stremińska, M A; Runia, W T; Termorshuizen, A J; Feil, H; Van Der Wurff, A W G

    2014-01-01

    In recent years, anaerobic soil disinfestation (ASD) has been proposed as an alternative control method of soil-borne plant pathogens. It involves adding a labile carbon source, irrigating the soil to stimulate decomposition of organic material and then covering the soil with air-tight plastic to limit gas exchange. During the ASD process, soil microorganisms switch from aerobic to anaerobic metabolism. As a result, by-products of anaerobic metabolism are released into the soil environment such as various organic acids and gases. These by-products are reported to have a negative effect on survival of soil-borne plant pathogens. However, the efficacy of ASD to reduce soil-borne pathogens in practice may vary significantly. Therefore, we studied the efficacy of the ASD process in two different soils. In addition, it was investigated whether a pre-treatment with an anaerobic bacterial inoculum prior to ASD affected the efficacy of the process. Two sandy soils (dune sand and glacial sand) were inoculated in 2 L soil microcosms. We tested the efficacy of ASD treatment against the potato cyst nematode Globodera pallida. For each soil, three treatments were used: control treatment (no Herbie addition, aerobic incubation), ASD 1 (organic substrate addition, anaerobic incubation) and ASD 2 (organic substrate and anaerobic bacterial inoculum addition, anaerobic incubation). Soil microcosms were incubated in the dark at 20°C for two weeks. We observed that anaerobic soil disinfestation treatments were highly effective against Potato Cyst Nematode (PCN), with pathogen being eradicated totally in all but one ASD treatment (glacial sand ASD2) within two weeks. The relative abundance of Firmicutes (spore-forming bacteria, often fermentative) in total bacteria increased significantly in ASD treated soils. Numbers of these bacteria correlated positively with increased concentrations of acetic and butyric acids in soil water phase in ASD treatments.

  2. Soil

    USDA-ARS?s Scientific Manuscript database

    Soil is a diverse natural material characterized by solid, liquid, and gas phases that impart unique chemical, physical, and biological properties. Soil provides many key functions, including supporting plant growth and providing environmental remediation. Monitoring key soil properties and processe...

  3. Soil spectral characterization

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.

    1981-01-01

    The spectral characterization of soils is discussed with particular reference to the bidirectional reflectance factor as a quantitative measure of soil spectral properties, the role of soil color, soil parameters affecting soil reflectance, and field characteristics of soil reflectance. Comparisons between laboratory-measured soil spectra and Landsat MSS data have shown good agreement, especially in discriminating relative drainage conditions and organic matter levels in unvegetated soils. The capacity to measure both visible and infrared soil reflectance provides information on other soil characteristics and makes it possible to predict soil response to different management conditions. Field and laboratory soil spectral characterization helps define the extent to which intrinsic spectral information is available from soils as a consequence of their composition and field characteristics.

  4. Soil biological indicators of soil health for a national soil health assessment

    USDA-ARS?s Scientific Manuscript database

    Soil is one of our nation's most valuable resources that provides life-sustaining functions. Billions of organisms live belowground and perform critical soil processes to support plant, animal, and human health aboveground. By shifting our view of soils from an inert growing material to a biological...

  5. Soil property effects on wind erosion of organic soils

    NASA Astrophysics Data System (ADS)

    Zobeck, Ted M.; Baddock, Matthew; Scott Van Pelt, R.; Tatarko, John; Acosta-Martinez, Veronica

    2013-09-01

    Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (OM > 20%) in half or more of the upper 80 cm. Forty two states have a total of 21 million ha of Histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss of crop productivity and degradation of soil, air, and water quality. Estimating wind erosion on Histosols has been determined by USDA-Natural Resources Conservation Service (NRCS) as a critical need for the Wind Erosion Prediction System (WEPS) model. WEPS has been developed to simulate wind erosion on agricultural land in the US, including soils with organic soil material surfaces. However, additional field measurements are needed to understand how soil properties vary among organic soils and to calibrate and validate estimates of wind erosion of organic soils using WEPS. Soil properties and sediment flux were measured in six soils with high organic contents located in Michigan and Florida, USA. Soil properties observed included organic matter content, particle density, dry mechanical stability, dry clod stability, wind erodible material, and geometric mean diameter of the surface aggregate distribution. A field portable wind tunnel was used to generate suspended sediment and dust from agricultural surfaces for soils ranging from 17% to 67% organic matter. The soils were tilled and rolled to provide a consolidated, friable surface. Dust emissions and saltation were measured using an isokinetic vertical slot sampler aspirated by a regulated suction source. Suspended dust was sampled using a Grimm optical particle size analyzer. Particle density of the saltation-sized material (>106 μm) was inversely related to OM content and varied from 2.41 g cm-3 for the soil with the lowest OM content to 1.61 g cm-3 for the soil with highest OM content. Wind erodible material and the geometric mean diameter of the surface soil were inversely related to dry clod

  6. Modelling the Impact of Soil Management on Soil Functions

    NASA Astrophysics Data System (ADS)

    Vogel, H. J.; Weller, U.; Rabot, E.; Stößel, B.; Lang, B.; Wiesmeier, M.; Urbanski, L.; Wollschläger, U.

    2017-12-01

    Due to an increasing soil loss and an increasing demand for food and energy there is an enormous pressure on soils as the central resource for agricultural production. Besides the importance of soils for biomass production there are other essential soil functions, i.e. filter and buffer for water, carbon sequestration, provision and recycling of nutrients, and habitat for biological activity. All these functions have a direct feed back to biogeochemical cycles and climate. To render agricultural production efficient and sustainable we need to develop model tools that are capable to predict quantitatively the impact of a multitude of management measures on these soil functions. These functions are considered as emergent properties produced by soils as complex systems. The major challenge is to handle the multitude of physical, chemical and biological processes interacting in a non-linear manner. A large number of validated models for specific soil processes are available. However, it is not possible to simulate soil functions by coupling all the relevant processes at the detailed (i.e. molecular) level where they are well understood. A new systems perspective is required to evaluate the ensemble of soil functions and their sensitivity to external forcing. Another challenge is that soils are spatially heterogeneous systems by nature. Soil processes are highly dependent on the local soil properties and, hence, any model to predict soil functions needs to account for the site-specific conditions. For upscaling towards regional scales the spatial distribution of functional soil types need to be taken into account. We propose a new systemic model approach based on a thorough analysis of the interactions between physical, chemical and biological processes considering their site-specific characteristics. It is demonstrated for the example of soil compaction and the recovery of soil structure, water capacity and carbon stocks as a result of plant growth and biological

  7. Effect of soil texture on the microwave emission from soils

    NASA Technical Reports Server (NTRS)

    Schmugge, T. J.

    1980-01-01

    The intensity brightness temperature of the microwave emission from the soil is determined primarily by its dielectric properties. The large difference between the dielectric constant of water and that of dry soil produces a strong dependence of the soil's dielectric constant on its moisture content. This dependence is effected by the texture of the soil because the water molecules close to the particle surface are tightly bound and do not contribute significantly to the dielectric properties. Since this surface area is a function of the particle size distribution (soil texture), being larger for clay soils with small particles, and smaller for sandy soils with larger particles; the dielectric properties will depend on soil texture. Laboratory measurements of the dielectric constant for soils are summarized. The dependence of the microwave emission on texture is demonstrated by measurements of brightness temperature from an aircraft platform for a wide range of soil textures. It is concluded that the effect of soil texture differences on the observed values can be normalized by expressing the soil moisture values as a percent field capacity for the soil.

  8. Linking Carbon Flux Dynamics and Soil Structure in Dryland Soils

    NASA Astrophysics Data System (ADS)

    DeCarlo, K. F.; Caylor, K. K.

    2016-12-01

    Biological sources in the form of microbes and plants play a fundamental role in determining the magnitude of carbon flux. However, the geophysical structure of the soil (which the carbon must pass through before entering the atmosphere) often serves as a constraining entity, which has the potential to serve as instigators or mitigators of those carbon and hydrologic flux processes. We characterized soil carbon dynamics in three dryland soil systems: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer (IRGA). Structure of the soil systems, with a focus on the macro-crack structure, were characterized using a combined resin-casting/X-ray imaging technique. Results show fundamental differences in carbon dynamics between the different soil systems/structures: control soils have gaussian distributions of carbon flux that decrease with progressive drying of the soil, while biocompacted soils exhibit exponentially distributed fluxes that do not regularly decrease with increased drying of the soil. Bioturbated soils also exhibit an exponential distribution of carbon flux, though at a much higher magnitude. These differences are evaluated in the context of the underlying soil structure: while the control soils exhibit a shallow and narrow crack structure, the biocompacted soils exhibit a "systematic" crack network with moderate cracking intensity and large depth. The deep crack networks of the biocompacted soils may serve to physically enhance an otherwise weak source of carbon via advection and/or convection, inducing fluxes that are equal or greater than an otherwise carbon-rich soil. The bioturbated soils exhibit a "surficial" crack network that is shallow but extensive, but additionally have deep holes known to convectively vent carbon, which may explain their periodically large carbon fluxes. Our results

  9. Soil experiment

    NASA Technical Reports Server (NTRS)

    Hutcheson, Linton; Butler, Todd; Smith, Mike; Cline, Charles; Scruggs, Steve; Zakhia, Nadim

    1987-01-01

    An experimental procedure was devised to investigate the effects of the lunar environment on the physical properties of simulated lunar soil. The test equipment and materials used consisted of a vacuum chamber, direct shear tester, static penetrometer, and fine grained basalt as the simulant. The vacuum chamber provides a medium for applying the environmental conditions to the soil experiment with the exception of gravity. The shear strength parameters are determined by the direct shear test. Strength parameters and the resistance of soil penetration by static loading will be investigated by the use of a static cone penetrometer. In order to conduct a soil experiment without going to the moon, a suitable lunar simulant must be selected. This simulant must resemble lunar soil in both composition and particle size. The soil that most resembles actual lunar soil is basalt. The soil parameters, as determined by the testing apparatus, will be used as design criteria for lunar soil engagement equipment.

  10. Soil organic matter as sole indicator of soil degradation

    Treesearch

    S.E. Obalum; G.U. Chibuike; S. Peth; Ying Ouyang

    2017-01-01

    Soil organic matter (SOM) is known to play vital roles in the maintenance and improvement of many soil properties and processes. These roles, which largely influence soil functions, are a pool of specific contributions of different components of SOM. The soil functions, in turn, normally define the level of soil degradation, viewed as quantifiable temporal changes in a...

  11. Method to measure soil matrix infiltration in forest soil

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Lei, Tingwu; Qu, Liqin; Chen, Ping; Gao, Xiaofeng; Chen, Chao; Yuan, Lili; Zhang, Manliang; Su, Guangxu

    2017-09-01

    Infiltration of water into forest soil commonly involves infiltration through the matrix body and preferential passages. Determining the matrix infiltration process is important in partitioning water infiltrating into the soil through the soil body and macropores to evaluate the effects of soil and water conservation practices on hillslope hydrology and watershed sedimentation. A new method that employs a double-ring infiltrometer was applied in this study to determine the matrix infiltration process in forest soil. Field experiments were conducted in a forest field on the Loess Plateau at Tianshui Soil and Water Conservation Experimental Station. Nylon cloth was placed on the soil surface in the inner ring and between the inner and outer rings of infiltrometers. A thin layer of fine sands were placed onto the nylon cloth to shelter the macropores and ensure that water infiltrates the soil through the matrix only. Brilliant Blue tracers were applied to examine the exclusion of preferential flow occurrences in the measured soil body. The infiltration process was measured, computed, and recorded through procedures similar to those of conventional methods. Horizontal and vertical soil profiles were excavated to check the success of the experiment and ensure that preferential flow did not occur in the measured soil column and that infiltration was only through the soil matrix. The infiltration processes of the replicates of five plots were roughly the same, thereby indicating the feasibility of the methodology to measure soil matrix infiltration. The measured infiltration curves effectively explained the transient process of soil matrix infiltration. Philip and Kostiakov models fitted the measured data well, and all the coefficients of determination were greater than 0.9. The wetted soil bodies through excavations did not present evidence of preferential flow. Therefore, the proposed method can determine the infiltration process through the forest soil matrix. This

  12. Soil organic carbon distribution in roadside soils of Singapore.

    PubMed

    Ghosh, Subhadip; Scharenbroch, Bryant C; Ow, Lai Fern

    2016-12-01

    Soil is the largest pool of organic carbon in terrestrial systems and plays a key role in carbon cycle. Global population living in urban areas are increasing substantially; however, the effects of urbanization on soil carbon storage and distribution are largely unknown. Here, we characterized the soil organic carbon (SOC) in roadside soils across the city-state of Singapore. We tested three hypotheses that SOC contents (concentration and density) in Singapore would be positively related to aboveground tree biomass, soil microbial biomass and land-use patterns. Overall mean SOC concentrations and densities (0-100 cm) of Singapore's roadside soils were 29 g kg -1 (4-106 g kg -1 ) and 11 kg m -2 (1.1-42.5 kg m -2 ) with median values of 26 g kg -1 and 10 kg m -2 , respectively. There was significantly higher concentration of organic carbon (10.3 g kg -1 ) in the top 0-30 cm soil depth compared to the deeper (30-50 cm, and 50-100 cm) soil depths. Singapore's roadside soils represent 4% of Singapore's land, but store 2.9 million Mg C (estimated range of 0.3-11 million Mg C). This amount of SOC is equivalent to 25% of annual anthropogenic C emissions in Singapore. Soil organic C contents in Singapore's soils were not related to aboveground vegetation or soil microbial biomass, whereas land-use patterns to best explain variance in SOC in Singapore's roadside soils. We found SOC in Singapore's roadside soils to be inversely related to urbanization. We conclude that high SOC in Singapore roadside soils are probably due to management, such as specifications of high quality top-soil, high use of irrigation and fertilization and also due to an optimal climate promoting rapid growth and biological activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. P$sup 32$-TESTS FOR INVESTIGATING THE COMPETITION BETWEEN TREE ROOTS AND REGROWTH IN SOUTHERN TAIGA FORESTS (in Russian)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karpov, V.G.

    1962-09-21

    Introduction of radioactive materials into soil nutrients represents an excellent tool for determining utilization of the nutrient and its ultimate distribution between the various components of the phytocaenosis; therefore P/sup 32/labeled solutions were used for clarifying the competition between the roots of mature birch, Betulla verrucosa, and fir, Picea excelsa, seedlings. The test area contained 30to 35-year-old trees at a density of about 7 to 8 thousand trees per bectare. During the summer of 1960 fir seedlings were planted in areas removed from the influence of the birch roots and near the trees without interfering with interaction between the 2more » systems; at the latter location the soil contained 730 to 1100 g/m/sup 2/ of roots. In July 1961 10 mg/liter P solution, labeled with P/sup 32/ was introduced into the soil; the original activity of the solution was 65 mu c/liter. Results indicated that competition by the birch roots strongly inhibits the P/sup 32/ uptake by the 2-year-old seedlings; the radioactivity of the fir needles planted in isolated areas was 5 to 8 times higher than that in seedlings planted near the mature trees. (TTT)« less

  14. What is Soil?

    Science.gov Websites

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils << 1 What is Soil? 2 The Skin of the Earth 3 Soil Ingredients 4 Soil Recipes 5 CLORPT for Short >> What Is Soil? Soils Make Life Plants grow in and from

  15. Impacts of soil moisture content on visual soil evaluation

    NASA Astrophysics Data System (ADS)

    Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Bondi, Giulia; Creamer, Rachel; Holden, Nick

    2017-04-01

    Visual Soil Examination and Evaluation (VSE) techniques offer tools for soil quality assessment. They involve the visual and tactile assessment of soil properties such as aggregate size and shape, porosity, redox morphology, soil colour and smell. An increasing body of research has demonstrated the reliability and utility of VSE techniques. However a number of limitations have been identified, including the potential impact of soil moisture variation during sampling. As part of a national survey of grassland soil quality in Ireland, an evaluation of the impact of soil moisture on two widely used VSE techniques was conducted. The techniques were Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and Visual Soil Assessment (VSA) (Shepherd, 2009). Both generate summarising numeric scores that indicate soil structural quality, though employ different scoring mechanisms. The former requires the assessment of properties concurrently and the latter separately. Both methods were deployed on 20 sites across Ireland representing a range of soils. Additional samples were taken for soil volumetric water (θ) determination at 5-10 and 10-20 cm depth. No significant correlation was observed between θ 5-10 cm and either VSE technique. However, VESS scores were significantly related to θ 10-20 cm (rs = 0.40, sig = 0.02) while VSA scores were not (rs = -0.33, sig = 0.06). VESS and VSA scores can be grouped into quality classifications (good, moderate and poor). No significant mean difference was observed between θ 5-10 cm or θ 10-20 cm according to quality classification by either method. It was concluded that VESS scores may be affected by soil moisture variation while VSA appear unaffected. The different scoring mechanisms, where the separate assessment and scoring of individual properties employed by VSA, may limit soil moisture effects. However, moisture content appears not to affect overall structural quality classification by either method. References

  16. Soil CO2 Dynamics in a Tree Island Soil of the Pantanal: The Role of Soil Water Potential

    PubMed Central

    Johnson, Mark S.; Couto, Eduardo Guimarães; Pinto Jr, Osvaldo B.; Milesi, Juliana; Santos Amorim, Ricardo S.; Messias, Indira A. M.; Biudes, Marcelo Sacardi

    2013-01-01

    The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO2 research has been conducted in this region. We evaluated soil CO2 dynamics in relation to primary controlling environmental parameters (soil temperature and soil water). Soil respiration was computed using the gradient method using in situ infrared gas analyzers to directly measure CO2 concentration within the soil profile. Due to the cost of the sensors and associated equipment, this study was unreplicated. Rather, we focus on the temporal relationships between soil CO2 efflux and related environmental parameters. Soil CO2 efflux during the study averaged 3.53 µmol CO2 m−2 s−1, and was equivalent to an annual soil respiration of 1220 g C m−2 y−1. This efflux value, integrated over a year, is comparable to soil C stocks for 0–20 cm. Soil water potential was the measured parameter most strongly associated with soil CO2 concentrations, with high CO2 values observed only once soil water potential at the 10 cm depth approached zero. This relationship was exhibited across a spectrum of timescales and was found to be significant at a daily timescale across all seasons using conditional nonparametric spectral Granger causality analysis. Hydrology plays a significant role in controlling CO2 efflux from the tree island soil, with soil CO2 dynamics differing by wetting mechanism. During the wet-up period, direct precipitation infiltrates soil from above and results in pulses of CO2 efflux from soil. The annual flood arrives later, and saturates soil from below. While CO2 concentrations in soil grew very high under both wetting mechanisms, the change in soil CO2 efflux was only significant when soils were wet from above. PMID:23762259

  17. Soil Forming Factors

    Science.gov Websites

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils << 1 Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

  18. Soil biodiversity and soil community composition determine ecosystem multifunctionality

    PubMed Central

    Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

    2014-01-01

    Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

  19. Soils and the soil cover of the Valley of Geysers

    NASA Astrophysics Data System (ADS)

    Kostyuk, D. N.; Gennadiev, A. N.

    2014-06-01

    The results of field studies of the soil cover within the tourist part of the Valley of Geysers in Kamchatka performed in 2010 and 2011 are discussed. The morphology of soils, their genesis, and their dependence on the degree of hydrothermal impact are characterized; the soil cover patterns developing in the valley are analyzed. On the basis of the materials provided by the Kronotskii Biospheric Reserve and original field data, the soil map of the valley has been developed. The maps of vegetation conditions, soil temperature at the depth of 15 cm, and slopes of the surface have been used for this purpose together with satellite imagery and field descriptions of reference soil profiles. The legend to the soil map includes nine soil units and seven units of parent materials and their textures. Soil names are given according to the classification developed by I.L. Goldfarb (2005) for the soils of hydrothermal fields. The designation of soil horizons follows the new Classification and Diagnostic System of Russian Soils (2004). It is suggested that a new horizon—a thermometamorphic horizon TRM—can be introduced into this system by analogy with other metamorphic (transformed in situ) horizons distinguished in this system. This horizon is typical of the soils partly or completely transformed by hydrothermal impacts.

  20. Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils.

    PubMed

    Unno, Yusuke; Tsukada, Hirofumi; Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun'ichi

    2017-04-01

    We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I - was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I - K d middle layer (i.e., with high radioiodide retention ability) differed between sites. K d of 125 I - was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I - . Further study is needed to clarify how radioiodide is retained and migrates in soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Spatial-temporal variability in GHG fluxes and their functional interpretation in RusFluxNet

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan; Meshalkina, Julia; Sarzhanov, Dmitriy; Mazirov, Ilia; Yaroslavtsev, Alex; Komarova, Tatiana; Tikhonova, Maria

    2016-04-01

    High spatial and temporal variability is mutual feature for most modern boreal landscapes in the European Territory of Russia. This variability is result of their relatively young natural and land-use age with very complicated development stories. RusFluxNet includes a functionally-zonal set of representative natural, agricultural and urban ecosystems from the Central Forest Reserve in the north till the Central Chernozemic Reserve in the south (more than 1000 km distance). Especial attention has been traditionally given to their soil cover and land-use detailed variability, morphogenetic and functional dynamics. Central Forest Biosphere Reserve (360 km to North-West from Moscow) is the principal southern-taiga one in the European territory of Russia with long history of mature spruce ecosystem structure and dynamics investigation. Our studies (in frame of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) have been concentrated on the soil carbon stocks and GHG fluxes spatial variability and dynamics due to dominated there windthrow and fallow-forest successions. In Moscow RTSAU campus gives a good possibility to develop the ecosystem and soil monitoring of GHG fluxes in the comparable sites of urban forest, field crops and lawn ecosystems taking especial attention on their meso- and micro-relief, soil cover patterns and subsoil, vegetation and land-use technologies, temperature and moisture spatial and temporal variability. In the Central Chernozemic Biosphere Reserve and adjacent areas we do the comparative analysis of GHG fluxes and balances in the virgin and mowed meadow-steppe, forest, pasture, cropland and three types of urban ecosystems with similar subsoil and relief conditions. The carried out researches have shown not only sharp (in 2-5 times) changes in GHG ecosystem and soil fluxes and balances due to seasonal and daily microclimate variation, vegetation and crop development but their essential (in 2-4 times) spatial variability due to

  2. Plant-soil feedbacks from 30-year family-specific soil cultures: phylogeny, soil chemistry and plant life stage.

    PubMed

    Mehrabi, Zia; Bell, Thomas; Lewis, Owen T

    2015-06-01

    Intraspecific negative feedback effects, where performance is reduced on soils conditioned by conspecifics, are widely documented in plant communities. However, interspecific feedbacks are less well studied, and their direction, strength, causes, and consequences are poorly understood. If more closely related species share pathogens, or have similar soil resource requirements, plants may perform better on soils conditioned by more distant phylogenetic relatives. There have been few empirical tests of this prediction across plant life stages, and none of which attempt to account for soil chemistry. Here, we test the utility of phylogeny for predicting soil feedback effects on plant survival and performance (germination, seedling survival, growth rate, biomass). We implement a full factorial experiment growing species representing five families on five plant family-specific soil sources. Our experiments exploit soils that have been cultured for over 30 years in plant family-specific beds at Oxford University Botanic Gardens. Plant responses to soil source were idiosyncratic, and species did not perform better on soils cultured by phylogenetically more distant relatives. The magnitude and sign of feedback effects could, however, be explained by differences in the chemical properties of "home" and "away" soils. Furthermore, the direction of soil chemistry-related plant-soil feedbacks was dependent on plant life stage, with the effects of soil chemistry on germination success and accumulation of biomass inversely related. Our results (1) suggest that the phylogenetic distance between plant families cannot predict plant-soil feedbacks across multiple life stages, and (2) highlight the need to consider changes in soil chemistry as an important driver of population responses. The contrasting responses at plant life stages suggest that studies focusing on brief phases in plant demography (e.g., germination success) may not give a full picture of plant-soil feedback effects.

  3. Soil Phosphorus Stoichiometry Drives Carbon Turnover Along a Soil C Gradient Spanning Mineral and Organic Soils Under Rice Cultivation

    NASA Astrophysics Data System (ADS)

    Hartman, W.; Ye, R.; Horwath, W. R.; Tringe, S. G.

    2014-12-01

    Soil carbon (C) cycling is linked to the availability of nutrients like nitrogen (N) and phosphorus (P). However, the role of soil P in influencing soil C turnover and accumulation is poorly understood, with most models focusing on C:N ratios based on the assumption that terrestrial ecosystems are N limited. To determine the effects of N and P availability on soil C turnover, we compared soil respiration over the course of a growing season in four adjacent rice fields with 5%, 10%, 20% and 25% soil C. In each of these fields, plots were established to test the effect of N additions on plant growth, using control and N addition treatments (80 kg N/ha urea). Although soil P was not manipulated in parallel, prior work has shown soil P concentrations decline markedly with increasing soil C content. Soil CO2 flux was monitored using static chambers at biweekly intervals during the growing season, along with porewater dissolved organic C and ammonium. Soils were collected at the end of the growing season, and tested for total C, N, and P, extractable N and P, pH, base cations and trace metals. Soil DNA was also extracted for 16S rRNA sequencing to profile microbial communities. Soil N additions significantly increased CO2 flux and soil C turnover (seasonal CO2 flux per unit soil C) in 5% and 10% C fields, but not in 20% or 25% C fields. Soil C content was closely related to soil N:P stoichiometry, with N:P ratios of ca. 12, 16, 24, and 56 respectively in the 5, 10, 20 and 25% C fields. Seasonal CO2 fluxes (per m2) were highest in 10% C soils. However, soil C turnover was inversely related to soil C concentrations, with the greatest C turnover at the lowest values of soil C. Soil C turnover showed stronger relationships with soil chemical parameters than seasonal CO2 fluxes alone, and the best predictors of soil C turnover were soil total and extractable N:P ratios, along with extractable P alone. Our results show that soil P availability and stoichiometry influence the

  4. Inoculation of soil native cyanobacteria to restore arid degraded soils

    NASA Astrophysics Data System (ADS)

    Raúl Román Fernández, José; Roncero Ramos, Beatriz; Chamizo de la Piedra, Sonia; Rodríguez Caballero, Emilio; Ángeles Muñoz Martín, M.; Mateo, Pilar; Cantón Castilla, Yolanda

    2017-04-01

    Restoration projects in semiarid lands often yield poor results. Water scarcity, low soil fertility, and poor soil structure strongly limit the survival and growth of planted seedlings in these areas. Under these conditions, a previous stage that improves edaphic conditions would turn out to a successful plant restoration. By successfully colonizing arid soils, cyanobacteria naturally provide suitable edaphic conditions, enhancing water availability, soil fertility and soil stability. Furthermore, cyanobacteria can be easily isolated and cultured ex-situ to produce high quantities of biomass, representing a potential tool to restore large areas efficiently. The objective of this study was to test the effect of inoculated cyanobacteria on degraded soils at three different semiarid areas from southeast Spain: Tabernas badlands, a limestone quarry located in Gádor, and grazed grassland in Las Amoladeras (Cabo de Gata). Soil native cyanobacteria belonging to three representative N-fixing genera (Nostoc, Scytonema and Tolypothrix) were isolated from such soils and cultured in BG110 medium. Each strain was inoculated (6 g m-2), separately and mixed (all in the same proportion), on Petri dishes with 80 g of each soil. Biocrust development was monitored during 3 months in these soils under laboratory conditions, at a constant temperature of 25oC. During the experiment, two irrigation treatments were applied simulating a dry (180 mm) and a wet (360 mm) rainfall year (average recorded in the study sites). After 3 months, net CO2 flux, spectral response and soil surface microtopography (1 mm spatial resolution) of inoculated and control soils was measured under wet conditions, all of them as a surrogate of biocrust development. Samples of the surface crust were collected in order to determine total soil organic carbon (SOC) content. The inoculated soils showed positive values of net CO2 flux, thus indicating a net CO2 uptake, whereas control soils showed CO2 fluxes closed to

  5. Soil moisture: Some fundamentals. [agriculture - soil mechanics

    NASA Technical Reports Server (NTRS)

    Milstead, B. W.

    1975-01-01

    A brief tutorial on soil moisture, as it applies to agriculture, is presented. Information was taken from books and papers considered freshman college level material, and is an attempt to briefly present the basic concept of soil moisture and a minimal understanding of how water interacts with soil.

  6. Effects of Biochar Amendment on Soil Properties and Soil Carbon Sequestration

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Zhu, S.

    2015-12-01

    Biochar addition to soils potentially affects various soil properties and soil carbon sequestration, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties as well as soil carbon sequestration. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates and the amount of soil carbon storage.

  7. Soil protists: a fertile frontier in soil biology research.

    PubMed

    Geisen, Stefan; Mitchell, Edward A D; Adl, Sina; Bonkowski, Michael; Dunthorn, Micah; Ekelund, Flemming; Fernández, Leonardo D; Jousset, Alexandre; Krashevska, Valentyna; Singer, David; Spiegel, Frederick W; Walochnik, Julia; Lara, Enrique

    2018-05-01

    Protists include all eukaryotes except plants, fungi and animals. They are an essential, yet often forgotten, component of the soil microbiome. Method developments have now furthered our understanding of the real taxonomic and functional diversity of soil protists. They occupy key roles in microbial foodwebs as consumers of bacteria, fungi and other small eukaryotes. As parasites of plants, animals and even of larger protists, they regulate populations and shape communities. Pathogenic forms play a major role in public health issues as human parasites, or act as agricultural pests. Predatory soil protists release nutrients enhancing plant growth. Soil protists are of key importance for our understanding of eukaryotic evolution and microbial biogeography. Soil protists are also useful in applied research as bioindicators of soil quality, as models in ecotoxicology and as potential biofertilizers and biocontrol agents. In this review, we provide an overview of the enormous morphological, taxonomical and functional diversity of soil protists, and discuss current challenges and opportunities in soil protistology. Research in soil biology would clearly benefit from incorporating more protistology alongside the study of bacteria, fungi and animals.

  8. Biological soil crusts as soil stabilizers: Chapter 16

    USGS Publications Warehouse

    Belnap, Jayne; Buedel, Burkhard; Weber, Bettina; Buedel, Burkhard; Belnap, Jayne

    2016-01-01

    Soil erosion is of particular concern in dryland regions, as the sparse cover of vascular plants results in large interspaces unprotected from the erosive forces of wind and water. Thus, most of these soil surfaces are stabilized by physical or biological soil crusts. However, as drylands are extensively used by humans and their animals, these crusts are often disturbed, compromising their stabilizing abilities. As a result, approximately 17.5% of the global terrestrial lands are currently being degraded by wind and water erosion. All components of biocrusts stabilize soils, including green algae, cyanobacteria, fungi, lichens, and bryophytes, and as the biomass of these organisms increases, so does soil stability. In addition, as lichens and bryophytes live atop the soil surface, they provide added protection from raindrop impact that cyanobacteria and fungi, living within the soil, cannot. Much research is still needed to determine the relative ability of individual species and suites of species to stabilize soils. We also need a better understanding of why some individuals or combination of species are better than others, especially as these organisms become more frequently used in restoration efforts.

  9. Soil degradation effect on biological activity in Mediterranean calcareous soils

    NASA Astrophysics Data System (ADS)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  10. Relationships between soil erosion risk, soil use and soil properties in Mediterranean areas. A comparative study of three typical sceneries

    NASA Astrophysics Data System (ADS)

    Gil, Juan; Priego-Navas, Mercedes; Zavala, Lorena M.; Jordán, Antonio

    2013-04-01

    Generally, literature shows that the high variability of rainfall-induced soil erosion is related to climatic differences, relief, soil properties and land use. Very different runoff rates and soil loss values have been reported in Mediterranean cropped soils depending on soil management practices, but also in soils under natural vegetation types. OBJECTIVES The aim of this research is to study the relationships between soil erosion risk, soil use and soil properties in three typical Mediterranean areas from southern Spain: olive groves under conventional tillage, minimum tillage and no-till practices, and soils under natural vegetation. METHODS Rainfall simulation experiments have been carried out in order to assess the relationship between soil erosion risk, land use, soil management and soil properties in olive-cropped soils under different types of management and soils under natural vegetation type from Mediterranean areas in southern Spain RESULTS Results show that mean runoff rates decrease from 35% in olive grove soils under conventional tillage to 25% in olive (Olea europaea) grove soils with minimum tillage or no-till practices, and slightly over 22% in soils under natural vegetation. Moreover, considering the different vegetation types, runoff rates vary in a wide range, although runoff rates from soils under holm oak (Quercus rotundifolia), 25.70%, and marginal olive groves , 25.31%, are not significantly different. Results from soils under natural vegetation show that the properties and nature of the organic residues play a role in runoff characteristics, as runoff rates above 50% were observed in less than 10% of the rainfall simulations performed on soils with a organic layer. In contrast, more than half of runoff rates from bare soils reached or surpassed 50%. Quantitatively, average values for runoff water losses increase up to 2.5 times in unprotected soils. This is a key issue in the study area, where mean annual rainfall is above 600 mm

  11. Soil color - a window for public and educators to understands soils

    NASA Astrophysics Data System (ADS)

    Libohova, Zamir; Beaudette, Dylan; Wills, Skye; Monger, Curtis; Lindbo, David

    2017-04-01

    Soil color is one of the most visually striking properties recorded by soil scientists around the world. Soil color is an important characteristic related to soil properties such organic matter, parent materials, drainage. It is a simplified way for the public and educators alike to understand soils and their functions. Soil color is a quick measurement that can be recorded by people using color charts or digital cameras, offering an opportunity for the citizen science projects to contribute to soil science. The US Soil Survey has recorded soil colors using Munsell color system for over 20,000 soil types representing a wide range of conditions throughout the Unites States. The objective of this research was to generate a US soil color map based on color descriptions from the Official Series Descriptions (OSDs). A color calculator developed in R and ArcMap were used to spatially display the soil colors. Soil colors showed vertical trends related to soil depth and horizontal trends related to parent material and climate. Soil colors represent development processes depending upon environment and time that have influenced their appearance and geographic distribution. Dark colors represent soils that are rich in organic matter, such as the soils of the Midwest USA, which are some of the most fertile soils in the world. These soils are relatively "young" in that they developed over the last 20,000 years in materials left behind after continental Glaciers retreated and reflect long- term prairie vegetation that dominated this area prior to European settlements. Dark soils of the Pacific Northwest reflect the influence of forests (and volcanic activity) but are shallower and less fertile than the deep dark Midwest soils. Soils of the eastern and southern Coastal Plains are older and are enriched with iron oxides ('rust') which gives them their red coloring. Soils of flood plains, like the broad Mississippi Valley, have multi-colored soils that reflect the process of

  12. Developing and using artificial soils to analyze soil microbial processes

    NASA Astrophysics Data System (ADS)

    Gao, X.; Cheng, H. Y.; Boynton, L.; Masiello, C. A.; Silberg, J. J.

    2017-12-01

    Microbial diversity and function in soils are governed by soil characteristics such as mineral composition, particles size and aggregations, soil organic matter (SOM), and availability of nutrients and H2O. The spatial and temporal heterogeneity of soils creates a range of niches (hotspots) differing in the availability of O2, H2O, and nutrients, which shapes microbial activities at scales ranging from nanometer to landscape. Synthetic biologists often examine microbial response trigged by their environment conditions in nutrient-rich aqueous media using single strain microbes. While these studies provided useful insight in the role of soil microbes in important soil biogeochemical processes (e.g., C cycling, N cycling, etc.), the results obtained from the over-simplified model systems are often not applicable natural soil systems. On the contrary, soil microbiologists examine microbial processes in natural soils using longer incubation time. However, due to its physical, chemical and biological complexity of natural soils, it is often difficult to examine soil characteristics independently and understand how each characteristic influences soil microbial activities and their corresponding soil functioning. Therefore, it is necessary to bridge the gap and develop a model matrix to exclude unpredictable influences from the environment while still reliably mimicking real environmental conditions. The objective of this study is to design a range of ecologically-relevant artificial soils with varying texture (particle size distribution), structure, mineralogy, SOM content, and nutrient heterogeneity. We thoroughly characterize the artificial soils for pH, active surface area and surface morphology, cation exchange capacity (CEC), and water retention curve. We demonstrate the effectiveness of the artificial soils as useful matrix for microbial processes, such as microbial growth and horizontal gene transfer (HGT), using the gas-reporting biosensors recently developed in

  13. [Effects of soil trituration size on adsorption of oxytetracycline on soils].

    PubMed

    Qi, Rui-Huan; Li, Zhao-Jun; Long, Jian; Fan, Fei-Fei; Liang, Yong-Chao

    2011-02-01

    In order to understand the effects of soil trituration size on adsorption of oxytetracycline (OTC) on soils, two contrasting soils including moisture soil and purplish soil were selected to investigate adsorption of OTC on these soils, at the scales of no more than 0.20 mm, 0.84 mm, 0.25 mm and 0.15 mm, using the method of batch equilibrium experiments respectively. The results presented as the following: (1) Adsorption amount of OTC on moisture soil and purplish soil increased with the sampling time, and reached to equilibration at 24 h. First-order kinetic model, second-order kinetic model, parabolic-diffusion kinetic model, Elovich kinetic model, and two-constant kinetic model could be used to fit the changes in adsorption on soils with sampling time. Adsorption of OTC on two soils consisted of two processes such as quick adsorption and slow adsorption. Quick adsorption process happened during the period of 0-0.5 h. The adsorption rates of OTC on soils were higher at the small trituration size than those at the large trituration size, and at the same trituration size, the k(f) of purplish soil was about two times higher than those of moisture soil. (2) Adsorption isotherms of OTC on two soils with different trituration sizes were deviated from the linear model. The data were fitted well to Freundlich and Langmuir models, with the correlation coefficients between 0.956 and 0.999. The values of k(f) and q(m) for purplish soil were higher than those for moisture soil. At the same soil, adsorption amount of OTC increased with the decreases of soil trituration size. The results suggested that it is important to select the appropriate trituration size, based on the physical and chemical properties such as soil particle composition and so on, when the fate of antibiotics on soils was investigated.

  14. Soil-solution speciation of Cd as affected by soil characteristics in unpolluted and polluted soils.

    PubMed

    Meers, Erik; Unamuno, Virginia; Vandegehuchte, Michiel; Vanbroekhoven, Karolien; Geebelen, Wouter; Samson, Roeland; Vangronsveld, Jaco; Diels, Ludo; Ruttens, Ann; Du Laing, Gijs; Tack, Filip

    2005-03-01

    Total metal content by itself is insufficient as a measure to indicate actual environmental risk. Understanding the mobility of heavy metals in the soil and their speciation in the soil solution is of great importance for accurately assessing environmental risks posed by these metals. In a first explorative study, the effects of general soil characteristics on Cd mobility were evaluated and expressed in the form of empirical formulations. The most important factors influencing mobility of Cd proved to be pH and total soil content. This may indicate that current legislation expressing the requirement for soil sanitation in Flanders (Belgium) as a function of total soil content, organic matter, and clay does not successfully reflect actual risks. Current legal frameworks focusing on total content, therefore, should be amended with criteria that are indicative of metal mobility and availability and are based on physicochemical soil properties. In addition, soil-solution speciation was performed using two independent software packages (Visual Minteq 2.23 and Windermere Humic Aqueous model VI [WHAM VI]). Both programs largely were in agreement in concern to Cd speciation in all 29 soils under study. Depending on soil type, free ion and the organically complexed forms were the most abundant species. Additional inorganic soluble species were sulfates and chlorides. Minor species in solution were in the form of nitrates, hydroxides, and carbonates, the relative importance of which was deemed insignificant in comparison to the four major species.

  15. Helping People Understand Soils - Perspectives from the US National Cooperative Soil Survey

    NASA Astrophysics Data System (ADS)

    Reich, Paul; Cheever, Tammy; Greene, Linda; Southard, Susan; Levin, Maxine; Lindbo, David L.; Monger, Curtis

    2017-04-01

    Throughout the history of the US National Cooperative Soil Survey (NCSS), soil science education has been a part of the mission to better understand one of our most precious natural resources: the Soil. The poster will highlight the many products and programs related to soils that USDA NRCS (soils.usda.gov) has developed over the years for K-12 and college/professional education. NRCS scientific publications covering topics on soil properties, soil classification, soil health and soil quality have become an important part of the university soil science curriculum. Classroom lesson plans and grade appropriate materials help K-12 teachers introduce soil concepts to students and include detailed instructions and materials for classroom demonstrations of soil properties. A Handbook for Collegiate Soils Contests support universities that conduct Collegiate Soil Judging contests.

  16. Soil warming alters microbial substrate use in alpine soils.

    PubMed

    Streit, Kathrin; Hagedorn, Frank; Hiltbrunner, David; Portmann, Magdalena; Saurer, Matthias; Buchmann, Nina; Wild, Birgit; Richter, Andreas; Wipf, Sonja; Siegwolf, Rolf T W

    2014-04-01

    Will warming lead to an increased use of older soil organic carbon (SOC) by microbial communities, thereby inducing C losses from C-rich alpine soils? We studied soil microbial community composition, activity, and substrate use after 3 and 4 years of soil warming (+4 °C, 2007-2010) at the alpine treeline in Switzerland. The warming experiment was nested in a free air CO2 enrichment experiment using depleted (13)CO2 (δ(13)C = -30‰, 2001-2009). We traced this depleted (13)C label in phospholipid fatty acids (PLFA) of the organic layer (0-5 cm soil depth) and in C mineralized from root-free soils to distinguish substrate ages used by soil microorganisms: fixed before 2001 ('old'), from 2001 to 2009 ('new') or in 2010 ('recent'). Warming induced a sustained stimulation of soil respiration (+38%) without decline in mineralizable SOC. PLFA concentrations did not reveal changes in microbial community composition due to soil warming, but soil microbial metabolic activity was stimulated (+66%). Warming decreased the amount of new and recent C in the fungal biomarker 18:2ω6,9 and the amount of new C mineralized from root-free soils, implying a shift in microbial substrate use toward a greater use of old SOC. This shift in substrate use could indicate an imbalance between C inputs and outputs, which could eventually decrease SOC storage in this alpine ecosystem. © 2013 John Wiley & Sons Ltd.

  17. Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

    USGS Publications Warehouse

    Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, Ji; Zhou, C.-Y.

    2006-01-01

    The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

  18. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    PubMed

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Digital Soil Mapping - A platform for enhancing soil learning

    NASA Astrophysics Data System (ADS)

    Owens, Phillip; Libohova, Zamir; Monger, Curtis; Lindbo, David; Schmidt, Axel

    2017-04-01

    The expansion of digital infrastructure and tools has generated massive data and information as well as a need for reliable processing and accurate interpretations. Digital Soil Mapping is no exception in that it has provided opportunities for professionals and the public to interact at field and training/workshop levels in order to better understand soils and their benefits. USDA-NRCS National Cooperative Soil Survey regularly conducts training and workshops for soil scientists and other professionals in the US and internationally. A combination of field experiences with workshops conducted in a class environment offers ideal conditions for enhancing soil learning experiences. Examples from US, Haiti and Central America show that Digital Soil Mapping (DSM) tools are very effective for understanding and visualizing soils and their functioning at different scales.

  20. Migratory birds are the source of highly toxic organic pollutants for indigenous people in the Russian Arctic

    NASA Astrophysics Data System (ADS)

    Pesiakova, A. A.; Gusakova, E. V.; Trofimova, A. N.; Sorokina, T. Yu

    2018-01-01

    Polychlorinated biphenyls are highly toxic organic contaminants. Due to their chemical properties they had wide application in industry and agriculture in the 20th century. In 2001 the production of PCBs has been prohibited almost worldwide. Environmental contamination has been found in soils, water, and air where there were PCB production sites. They have been detected in fish, birds and animals of migratory species, retaining transboarding transfer. Several migratory species of birds (Taiga bean goose, greater white-fronted goose, lesser white fronted goose and barnacle goose) are a diet for indigenous people. PCBs accumulating in the human body affect all systems and organs. This article reviews the contribution of migratory bird species in transboarding transfer of highly toxic contaminants in the Nenets Autonomous Area, Kolguev island (Russian Arctic).

  1. Soil carbon

    Treesearch

    Charles H. Perry; Michael C. Amacher

    2007-01-01

    Why Is Soil Carbon Important? The sequestration of carbon by forest and agricultural soils has the potential to significantly reduce greenhouse gas concentrations (Pacala and Socolow 2004). Many countries are implementing field inventories of soil carbon, often combined with data from other sources, to estimate soil carbon sequestration rates and amounts (Kurz and Apps...

  2. Addition of Rubber to soil damages the functional diversity of soil.

    PubMed

    Goswami, Madhurankhi; Bhattacharyya, Purnita; Tribedi, Prosun

    2017-07-01

    Rubber is a polymer of isoprene, consisting mainly of cis-1,4-polyisoprene units. The unmanageable production and its irresponsible disposal pose severe threats to environmental ecology. Therefore, the current study focuses extensively on the ill-effects of Rubber disposal on soil microbial functional diversity as it reflects the health of ecosystem by acting as a key component in ecosystem productivity. To investigate the effect of Rubber on soil microbial functional diversity, soil samples were collected from landfill sites and three different soil microcosms (Rubber treated, untreated, and sterile soil) were prepared. The soil enzymatic activity was determined by fluorescein diacetate hydrolysis followed by the determination of the microbial metabolic potential and functional diversity by average well color development and Shannon-Weaver index (H), respectively. BiOLOG ECO plates were used for determining the microbial functional diversity of the soil microcosms. Higher heterotrophic microbial count as well as higher soil microbial activity was observed in Rubber untreated soil than Rubber treated soil microcosm. The result indicated that the addition of Rubber to soil reduced soil heterotrophic microbial count and soil microbial activity considerably. Similarly, soil microbial metabolic potential as well as microbial functional diversity of soil had been decreased by the addition of Rubber gloves in it. Variation in soil microbial metabolic spectrum between Rubber treated and untreated microcosm was confirmed by multivariate analysis. Collectively, all the results demonstrated that the addition of Rubber to soil reduced the soil microbial functional diversity considerably. Therefore, it is necessary for the commission of serious steps regarding Rubber disposal and protection of the environment from serious environmental issues.

  3. Predicting Soluble Nickel in Soils Using Soil Properties and Total Nickel.

    PubMed

    Zhang, Xiaoqing; Li, Jumei; Wei, Dongpu; Li, Bo; Ma, Yibing

    2015-01-01

    Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significant parameters in predicting soluble Ni concentrations with the adjusted determination coefficients (Radj2) values of 0.75 and 0.68 for soils spiked with soluble Ni salt and the spiked soils leached with artificial rainwater to mimic field conditions, respectively. However, when the soils were divided into three categories (pH < 7, 7-8 and > 8), they obtained better predictions with Radj2 values of 0.78-0.90 and 0.79-0.94 for leached and unleached soils, respectively. Meanwhile, the other soil properties, such as amorphous Fe and Al oxides and clay, were also found to be important for determining soluble Ni concentrations, indicating that they were also presented as active adsorbent surfaces. Additionally, the whole soil speciation including bulk soil properties and total soils Ni concentrations were analyzed by mechanistic speciation models WHAM VI and Visual MINTEQ3.0. It was found that WHAM VI provided the best predictions for the soils with pH < 7, was relatively reasonable for pH 7 to 8, and gave an overestimation for pH > 8. The Visual MINTEQ3.0 could provide better estimation for pH < 8 and meanwhile quite reasonable results for pH > 8. These results indicated the possibility and applicability of these models to predict soil soluble Ni concentration by soil properties.

  4. Keys to soil taxonomy by soil survey staff (sixth edition)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1994-12-31

    This publication, Keys to Soil Taxonomy, serves two purposes. It provides the taxonomic keys necessary for the classification of soils according to Soil Taxonomy in a form that can be used easily in the field, and it also acquaints users of Soil Taxonomy with recent changes in the classification system. This volume includes all revisions of the keys that have so far been approved, replacing the original keys in Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys (1975), the work on which this abridged version, first published in 1983, is based. This publication incorporatesmore » all amendments approved to date and published in National Soil Taxonomy Handbook (NSTH) Issues 1-17.« less

  5. Soils in art as a teaching tool in soil science

    NASA Astrophysics Data System (ADS)

    Poch, Rosa M.

    2017-04-01

    The representation of soils in the different artistic expressions occurs much less often than that of other naturalistic scientific disciplines, like botany or zoology, due to the minor perception of soils as a natural body since the humans started to express themselves through art. Nevertheless, painters, writers and even musicians and film directors have been forced to deal with soils in their works, as a component of the landscape and as the main actor of the various soil functions. Even if the artists are not aware of soils in the sense of soil science - a study object - their observation of nature invariably leads to express their properties, the problems due to their misuse or degradation and their management practices. These art works have a great value when teaching soil science to students, because the latter can learn to intepret and go beyond the artist's observation and therefore they can appreciate the perception of soils and soil properties along the history of humankind. Paintings from various periods can be used as exercises, mainly those depicting landscapes or agricultural works. Some examples are Dutch landscape painters, as Brueghel the Young showing detailed soil erosion features; or Wijnants (XVII century) depicting very clear podzols on sand dunes. Also the impressionists (Van Gogh, Cézanne, Gaugin), or the landscapes of the romantic nationalists (XIX- early XX century) show forest or agricultural soils that can be used either to deduce soil forming processes and describe horizons, or to discuss the effectivity of soil management practices (deforestation, burning, plowing, terracing). Also some pieces of literature can be used either for illustrating real soil landscapes and soil-water relationships (Steinbeck's "The Grapes of Wrath") or in case of fiction literature, as exercice for soil mapping (Tolkien's Middle Earth in "The Hobbit" and "The Lord of the Rings"). Films as "The field" (Jim Sheridan, 1990) or "Corn Island" (George Ovasvili

  6. Plant-soil-microbe interactions regulating soil C storage

    NASA Astrophysics Data System (ADS)

    Hofmockel, K. S.; Bach, E.; Williams, R.

    2016-12-01

    Integration across disciplines is required to identify the emergent microbial scale properties that regulate the release or occlusion of plant inputs in soil organic matter. To investigate how micro-scale processes influence soil carbon cycling, we measured microbial community composition and activity within soil aggregates monthly over two growing seasons of a long-term bioenergy field experiment. Using a biologically sensitive sieving technique, soil aggregates were isolated and microbial community activity and composition were measured. This aggregate approach revealed biogeochemical processes regulating C cycling that are not detected using whole soil approaches. Soil aggregation influenced microbe-substrate interactions, where diversified perennial grassland systems supported greater aggregation and reduced severity of aggregate turnover compared to corn systems. Aggregate turnover and concurrent increases in activity resulted in greater microbial biomass and physical protection of soil organic matter in prairie systems, especially fertilized prairies. Fertilized prairie enhanced microbial biomass, enzyme activity, and soil aggregation despite greater root biomass in unfertilized prairie. Independent of ecosystem or sampling date, N-acetyl-glucosaminidase activity and Nitrospirae abundance was greatest in large macroaggregates (>2000 µm), which harbored the highest C:N; cellobiohydrolase activity and Acidobacteria abundance was greatest in microaggregates (<250 µm) which had the lowest C:N. Aggregate fractions differed in microbial community composition (bacteria, archaea, and fungi) and potential enzyme activity, independent of cropping system. Microaggregates harbored significantly greater microbial diversity and richness across all bioenergy cropping systems. Together these results suggest that by mediating access to substrates, soil structure (aggregates) can influence the microbial community composition and extracellular enzyme activity to regulate

  7. Basic Soils. Revision.

    ERIC Educational Resources Information Center

    Montana State Univ., Bozeman. Dept. of Agricultural and Industrial Education.

    This curriculum guide is designed for use in teaching a course in basic soils that is intended for college freshmen. Addressed in the individual lessons of the unit are the following topics: the way in which soil is formed, the physical properties of soil, the chemical properties of soil, the biotic properties of soil, plant-soil-water…

  8. Effect of soil moisture on the temperature sensitivity of Northern soils

    NASA Astrophysics Data System (ADS)

    Minions, C.; Natali, S.; Ludwig, S.; Risk, D.; Macintyre, C. M.

    2017-12-01

    Arctic and boreal ecosystems are vast reservoirs of carbon and are particularly sensitive to climate warming. Changes in the temperature and precipitation regimes of these regions could significantly alter soil respiration rates, impacting atmospheric concentrations and affecting climate change feedbacks. Many incubation studies have shown that both temperature and soil moisture are important environmental drivers of soil respiration; this relationship, however, has rarely been demonstrated with in situ data. Here we present the results of a study at six field sites in Alaska from 2016 to 2017. Low-power automated soil gas systems were used to measure soil surface CO2 flux from three forced diffusion chambers and soil profile concentrations from three soil depth chambers at hourly intervals at each site. HOBO Onset dataloggers were used to monitor soil moisture and temperature profiles. Temperature sensitivity (Q10) was determined at each site using inversion analysis applied over different time periods. With highly resolved data sets, we were able to observe the changes in soil respiration in response to changes in temperature and soil moisture. Through regression analysis we confirmed that temperature is the primary driver in soil respiration, but soil moisture becomes dominant beyond a certain threshold, suppressing CO2 flux in soils with high moisture content. This field study supports the conclusions made from previous soil incubation studies and provides valuable insights into the impact of both temperature and soil moisture changes on soil respiration.

  9. Variations in Soil Microbial Biomass Carbon and Soil Dissolved Organic Carbon in the Re-Vegetation of Hilly Slopes with Purple Soil.

    PubMed

    Yang, Ning; Zou, Dongsheng; Yang, Manyuan; Lin, Zhonggui

    2016-01-01

    Crust restoration is increasingly being done but we lack quantitative information on soil improvements. The study aimed to elucidate the dynamics involving soil microbial biomass carbon and soil dissolved organic carbon in the re-vegetation chronosequences of a hillslope land with purple soil in Hengyang, Hunan Province. The soil can cause serious disasters with both soil erosion and seasonal drought, and also becomes a typical representative of ecological disaster area in South China. Using the space-for-time method, we selected six typical sampling plots, designated as follows: grassplot community, meadow thicket community, frutex community, frutex and arbor community, arbor community, and top-level vegetation community. These plots were established to analyze the changes in soil microbial biomass carbon, soil microbial quotien, dissolved organic carbon, dissolved organic carbon/soil organic carbon, and soil basal respiration in 0-10, 10-20, and 20-40 cm soil layers. The relationships of these parameters with soils physic-chemical properties were also determined. The ecological environment of the 6 plant communities is similar and typical; they denoted six different successive stages of restoration on hillslopes with purple soils in Hengyang, Hunan Province. The soil microbial biomass carbon and soil basal respiration contents decreased with increasing soil depth but increased with re-vegetation. By contrast, soil microbial quotient increased with increasing soil depth and re-vegetation. From 0-10 cm soil layer to 20-40 cm soil layer, the dissolved organic carbon content decreased in different re-vegetation stages. In the process of re-vegetation, the dissolved organic carbon content increased in the 0-10 and 10-20 cm soil layers, whereas the dissolved organic carbon content decreased after an initial increase in the 20-40 cm soil layers. Meanwhile, dissolved organic carbon/soil organic carbon increased with increasing soil depth but decreased with re

  10. Variations in Soil Microbial Biomass Carbon and Soil Dissolved Organic Carbon in the Re-Vegetation of Hilly Slopes with Purple Soil

    PubMed Central

    Yang, Ning; Zou, Dongsheng; Yang, Manyuan; Lin, Zhonggui

    2016-01-01

    Crust restoration is increasingly being done but we lack quantitative information on soil improvements. The study aimed to elucidate the dynamics involving soil microbial biomass carbon and soil dissolved organic carbon in the re-vegetation chronosequences of a hillslope land with purple soil in Hengyang, Hunan Province. The soil can cause serious disasters with both soil erosion and seasonal drought, and also becomes a typical representative of ecological disaster area in South China. Using the space-for-time method, we selected six typical sampling plots, designated as follows: grassplot community, meadow thicket community, frutex community, frutex and arbor community, arbor community, and top-level vegetation community. These plots were established to analyze the changes in soil microbial biomass carbon, soil microbial quotien, dissolved organic carbon, dissolved organic carbon/soil organic carbon, and soil basal respiration in 0–10, 10–20, and 20–40 cm soil layers. The relationships of these parameters with soils physic-chemical properties were also determined. The ecological environment of the 6 plant communities is similar and typical; they denoted six different successive stages of restoration on hillslopes with purple soils in Hengyang, Hunan Province. The soil microbial biomass carbon and soil basal respiration contents decreased with increasing soil depth but increased with re-vegetation. By contrast, soil microbial quotient increased with increasing soil depth and re-vegetation. From 0–10 cm soil layer to 20–40 cm soil layer, the dissolved organic carbon content decreased in different re-vegetation stages. In the process of re-vegetation, the dissolved organic carbon content increased in the 0–10 and 10–20 cm soil layers, whereas the dissolved organic carbon content decreased after an initial increase in the 20–40 cm soil layers. Meanwhile, dissolved organic carbon/soil organic carbon increased with increasing soil depth but decreased

  11. Introductory Soil Science Exercises Using USDA Web Soil Survey

    ERIC Educational Resources Information Center

    Post, Christopher J.; Mikhailova, Elena; McWhorter, Christopher M.

    2007-01-01

    The USDA, Natural Resource Conservation Service (NRCS) Web Soil Survey is a valuable teaching tool for soil science education. By incorporating the Web Soil Survey into an undergraduate-level course, students are able to use the most detailed digital soil survey information without the steep learning curve associated with geographic information…

  12. The soil water regime of stony soils in a mountain catchment

    NASA Astrophysics Data System (ADS)

    Hlaváčiková, Hana; Danko, Michal; Holko, Ladislav; Hlavčo, Jozef; Novák, Viliam

    2016-04-01

    Investigation of processes related to runoff generation is an important topic in catchment hydrology. Observations are usually carried out in small catchments or on hillslopes. Many of such catchments are located in mountain or forested areas. From many studies it is evident that soil conditions and soil characteristics are one of the crucial factors in runoff generation. Mountainous or forest soils have usually high rock fragments content. Nevertheless, the influence of soil stoniness on water flow was not sufficiently studied up to now at catchment and hillslope scales due to flow formation complexity or problems with stony soil properties measurement (installing measuring devices, interpretation of measured data). Results of this work can be divided in two groups: (1) hydrophysical properties of stony soils measurements, and (2) water flow dynamic modelling in stony soils. Properties of stony soils were measured in the Jalovecky creek catchment, the Western Tatra Mts., Slovakia. Altitude of particular study sites varies from 780 to1500 m a.s.l. We measured and analyzed the stoniness of reference soil profiles, as well as retention properties of stony soils (fine soil fraction and rock fragments separately) and hydraulic conductivities of surface and subsurface soil layers. The methodology for determination of the effective hydrophysical properties of a stony soil (later used in modelling) was proposed using results from measurements, calculation, and numerical Darcy experiments. Modelling results show that the presence of rock fragments with low water retention in a stony soil with moderate or high stoniness can cause the soil water storage decrease by 16-31% in compared to the soil without rock fragments. In addition, decreased stony soil retention capacity resulted in faster outflow increase at the bottom of the soil profile during non-ponding infiltration. Furthermore, the presence of rock fragments can increase maximum outflow value. It is not possible to

  13. Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a γ-sterilized wettable and repellent soil.

    PubMed

    Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng

    2012-12-01

    Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  14. Conserving Soil.

    ERIC Educational Resources Information Center

    Soil Conservation Service (USDA), Washington, DC.

    Designed as enrichment materials for grades six through nine, this program is an interdisciplinary study of soils. As part of the program students: (1) examine soil organisms; (2) research history of local Native Americans to see how they and others have used the land and its soils; (3) investigate how soils are degraded and how they are conserved…

  15. Soil gas radon concentrations measurements in terms of great soil groups.

    PubMed

    Içhedef, Mutlu; Saç, Müslim Murat; Camgöz, Berkay; Bolca, Mustafa; Harmanşah, Çoşkun

    2013-12-01

    In this study, soil gas radon concentrations were investigated according to locations, horizontal soil layers and great soil groups around Tuzla Fault, Seferihisar-İzmir. Great soil groups are a category that described the horizontal soil layers under soil classification system and distributions of radon concentration in the great soil groups are firstly determined by the present study. According to the obtained results, it has been showed that the radon concentrations in the Koluvial soil group are higher than the other soil groups in the region. Also significant differences on location in same great soil group were determined. The radon concentrations in the Koluvial soil groups were measured with respect to soil layers structures (A, B, C1, and C2). It has been observed that the values increase with depth of soil (C2>C1>B>A). The main reason may be due to the meteorological factors that have limited effect on radon escape from deep layers. Although fault lines pass thought the study area radon concentrations were varied location to location, layer to layer and great group to great group. The study shows that a detailed location description should be performed before soil radon measurements for earthquake predictions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Variability of the soil-to-plant radiocaesium transfer factor for Japanese soils predicted with soil and plant properties.

    PubMed

    Uematsu, Shinichiro; Vandenhove, Hildegarde; Sweeck, Lieve; Van Hees, May; Wannijn, Jean; Smolders, Erik

    2016-03-01

    Food chain contamination with radiocaesium (RCs) in the aftermath of the Fukushima accident calls for an analysis of the specific factors that control the RCs transfer. Here, soil-to-plant transfer factors (TF) of RCs for grass were predicted from the potassium concentration in soil solution (mK) and the Radiocaesium Interception Potential (RIP) of the soil using existing mechanistic models. The mK and RIP were (a) either measured for 37 topsoils collected from the Fukushima accident affected area or (b) predicted from the soil clay content and the soil exchangeable potassium content using the models that had been calibrated for European soils. An average ammonium concentration was used throughout in the prediction. The measured RIP ranged 14-fold and measured mK varied 37-fold among the soils. The measured RIP was lower than the RIP predicted from the soil clay content likely due to the lower content of weathered micas in the clay fraction of Japanese soils. Also the measured mK was lower than that predicted. As a result, the predicted TFs relying on the measured RIP and mK were, on average, about 22-fold larger than the TFs predicted using the European calibrated models. The geometric mean of the measured TFs for grass in the affected area (N = 82) was in the middle of both. The TFs were poorly related to soil classification classes, likely because soil fertility (mK) was obscuring the effects of the soil classification related to the soil mineralogy (RIP). This study suggests that, on average, Japanese soils are more vulnerable than European soils at equal soil clay and exchangeable K content. The affected regions will be targeted for refined model validation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The influence of soil organic matter chemistry and site/soil properties in predicting the decomposability of tundra soils

    NASA Astrophysics Data System (ADS)

    Matamala, R.; Jastrow, J. D.; Fan, Z.; Liang, C.; Calderon, F.; Michaelson, G.; Mishra, U.; Ping, C. L.

    2017-12-01

    With the increase in high latitude warming, there is a need to better understand the potential vulnerability of soil organic matter (SOM) stored in Arctic regions. In this study, we used mid infrared spectroscopy (MidIR) to determine the influence of soil chemistry and site properties in the short-term mineralization potential of SOM stored in tundra soils. Soils from the active and permafrost layers were collected from four tundra sites on the Coastal Plain, and Arctic Foothills of the North Slope of Alaska and were incubated for 60 days at a range of temperatures. Site and soil properties including acidic versus non-acidic tundra, lowland versus upland areas, total soil organic carbon (TOC) and total nitrogen (TN) concentrations, 60-day carbon mineralization potential (CMP), MidIR spectra and the chemical composition of the SOM stored in these soils were determined. Partial least squares (PLS) models for CMP versus MidIR spectra were produced upon splitting the dataset into site and soil properties categories. We found that SOM composition determined by MidIR spectroscopy was most effective in predicting CMP for tundra soils and it was most relevant for the active-layer mineral and upper permafrost soil horizons and/or soils with C concentrations of 10% or lower. Analysis of the factor loadings and standardized beta coefficients from the CMP PLS models indicated that spectral bands associated with clay contents, phenolic OH, aliphatic, silicates, carboxylic acids, and polysaccharides were influential for lower TOC soils, but these bands were less important for higher TOC soils. High TOC soils were influenced by a combination of other factors. Our results suggest that different factors affect the short-term CMP of SOM in tundra soils depending on the amount of TOC present. We show MidIR as a powerful tool for quickly and reasonably estimating the short-term CMP of tundra soils. Widespread application of MidIR measurements to already collected and archived tundra

  18. Polychlorinated biphenyls in Nepalese surface soils: Spatial distribution, air-soil exchange, and soil-air partitioning.

    PubMed

    Yadav, Ishwar Chandra; Devi, Ningombam Linthoingambi; Li, Jun; Zhang, Gan

    2017-10-01

    Regardless of the ban on the polychlorinated biphenyls (PCBs) decade ago, significant measures of PCBs are still transmitted from essential sources in cities and are all inclusive ecological contaminants around the world. In this study, the concentrations of PCBs in soil, the air-soil exchange of PCBs, and the soil-air partitioning coefficient (K SA ) of PCBs were investigated in four noteworthy urban areas in Nepal. Overall, the concentrations of ∑ 30 PCBs ranged from 10 to 59.4ng/g dry weight; dw (mean 12.2ng/g ±11.2ng/g dw). The hexa-CBs (22-31%) was most dominant among several PCB-homologues, followed by tetra-CBs (20-29%), hepta-CBs (12-21%), penta-CBs (15-17%) and tri-CBs (9-19%). The sources of elevated level of PCBs discharge in Nepalese soil was identified as emission from transformer oil, lubricants, breaker oil, cutting oil and paints, and cable insulation. Slightly strong correlation of PCBs with TOC than BC demonstrated that amorphous organic matter (AOM) assumes a more critical part in holding of PCBs than BC in Nepalese soil. The fugacity fraction (ff) results indicated the soil being the source of PCB in air through volatilization and net transport from soil to air. The soil-air partitioning coefficient study suggests the absorption by soil organic matter control soil-air partitioning of PCBs. Slightly weak but positive correlation of measured Log K SA with Log K OA (R 2 = 0.483) and Log K BC-A (R 2 = 0.438) suggests that both Log K OA and Log K BC-A can predict soil-air partitioning to lesser extent for PCBs. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Derivation of Soil Ecological Criteria for Copper in Chinese Soils.

    PubMed

    Wang, Xiaoqing; Wei, Dongpu; Ma, Yibing; McLaughlin, Mike J

    2015-01-01

    Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database. Second, the compiled data were corrected with leaching and aging factors to minimize the differences between laboratory and field conditions. Before Cu ecotoxicity data were entered into a species sensitivity distribution (SSD), they were normalized with Cu ecotoxicity predictive models to modify the effects of soil properties on Cu ecotoxicity. The PNEC value was set equal to the hazardous concentration for x% of the species (HCx), which could be calculated from the SSD curves, without an additional assessment factor. Finally, predictive models for HCx based on soil properties were developed. The soil properties had a significant effect on the magnitude of HCx, with HC5 varying from 13.1 mg/kg in acidic soils to 51.9 mg/kg in alkaline non-calcareous soils. The two-factor predictive models based on soil pH and cation exchange capacity could predict HCx with determination coefficients (R2) of 0.82-0.91. The three-factor predictive models--that took into account the effect of soil organic carbon--were more accurate than two-factor models, with R2 of 0.85-0.99. The predictive models obtained here could be used to calculate soil-specific criteria. All results obtained here could provide a scientific basis for revision of current Chinese soil environmental quality standards, and the approach adopted in this study could be used as a pragmatic framework for

  20. Derivation of Soil Ecological Criteria for Copper in Chinese Soils

    PubMed Central

    Wang, Xiaoqing; Wei, Dongpu; Ma, Yibing; McLaughlin, Mike J.

    2015-01-01

    Considerable information on copper (Cu) ecotoxicity as affected by biological species and abiotic properties of soils has been collected from the last decade in the present study. The information on bioavailability/ecotoxicity, species sensitivity and differences in laboratory and field ecotoxicity of Cu in different soils was collated and integrated to derive soil ecological criteria for Cu in Chinese soils, which were expressed as predicted no effect concentrations (PNEC). First, all ecotoxicity data of Cu from bioassays based on Chinese soils were collected and screened with given criteria to compile a database. Second, the compiled data were corrected with leaching and aging factors to minimize the differences between laboratory and field conditions. Before Cu ecotoxicity data were entered into a species sensitivity distribution (SSD), they were normalized with Cu ecotoxicity predictive models to modify the effects of soil properties on Cu ecotoxicity. The PNEC value was set equal to the hazardous concentration for x% of the species (HCx), which could be calculated from the SSD curves, without an additional assessment factor. Finally, predictive models for HCx based on soil properties were developed. The soil properties had a significant effect on the magnitude of HCx, with HC5 varying from 13.1 mg/kg in acidic soils to 51.9 mg/kg in alkaline non-calcareous soils. The two-factor predictive models based on soil pH and cation exchange capacity could predict HCx with determination coefficients (R2) of 0.82–0.91. The three-factor predictive models – that took into account the effect of soil organic carbon – were more accurate than two-factor models, with R2 of 0.85–0.99. The predictive models obtained here could be used to calculate soil-specific criteria. All results obtained here could provide a scientific basis for revision of current Chinese soil environmental quality standards, and the approach adopted in this study could be used as a pragmatic

  1. Complex linkage between soil, soil water, atmosphere and Eucalyptus Plantations

    NASA Astrophysics Data System (ADS)

    Shukla, C.; Tiwari, K. N.

    2017-12-01

    Eucalyptus is most widely planted genus grown in waste land of eastern region of India to meet the pulp industry requirements. Sustainability of these plantations is of concern because in spite of higher demand water and nutrients of plantations, they are mostly planted on low-fertility soils. This study has been conducted to quantify effect of 25 years old, a fully established eucalyptus plantations on i.) Alteration in physico-chemical and hydrological properties of soil of eucalyptus plantation in comparison to soil of natural grassland and ii.) Spatio-temporal variation in soil moisture under eucalyptus plantations. Soil physico-chemical properties of two adjacent plots covered with eucatuptus and natural grasses were analyzed for three consecutive depths (i.e. 0-30 cm, 30-60 cm and 60-90 cm) with five replications in each plot. Soil infiltration rate and saturated hydraulic conductivity (Ks) were measured in-situ to incorporate the influence of macro porosity caused due to roots of plantations. Daily soil moisture at an interval of 10 cm upto 160 cm depth with 3 replications and Leaf Area Index (LAI) at an interval of 15 days with 5 replications were recorded over the year. Significant variations found at level of 0.05 between soil properties of eucalyptus and natural grass land confirm the effect of plantations on soil properties. Comparative results of soil properties show significant alteration in soil texture such as percent of sand, organic matter and Ks found more by 20%, 9% and 22% respectively in eucalyptus plot as compare to natural grass land. Available soil moisture (ASM) was found constantly minimum in top soil excluding rainy season indicate upward movement of water and nutrients during dry season. Seasonal variation in temperature (T), relative humidity (RH) and leaf area index (LAI) influenced the soil moisture extraction phenomenon. This study clearly stated the impact of long term establishment of eucalyptus plantations make considerable

  2. Predicting Soluble Nickel in Soils Using Soil Properties and Total Nickel

    PubMed Central

    Zhang, Xiaoqing; Li, Jumei; Wei, Dongpu; Li, Bo; Ma, Yibing

    2015-01-01

    Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significant parameters in predicting soluble Ni concentrations with the adjusted determination coefficients (Radj 2) values of 0.75 and 0.68 for soils spiked with soluble Ni salt and the spiked soils leached with artificial rainwater to mimic field conditions, respectively. However, when the soils were divided into three categories (pH < 7, 7–8 and > 8), they obtained better predictions with Radj 2 values of 0.78–0.90 and 0.79–0.94 for leached and unleached soils, respectively. Meanwhile, the other soil properties, such as amorphous Fe and Al oxides and clay, were also found to be important for determining soluble Ni concentrations, indicating that they were also presented as active adsorbent surfaces. Additionally, the whole soil speciation including bulk soil properties and total soils Ni concentrations were analyzed by mechanistic speciation models WHAM VI and Visual MINTEQ3.0. It was found that WHAM VI provided the best predictions for the soils with pH < 7, was relatively reasonable for pH 7 to 8, and gave an overestimation for pH > 8. The Visual MINTEQ3.0 could provide better estimation for pH < 8 and meanwhile quite reasonable results for pH > 8. These results indicated the possibility and applicability of these models to predict soil soluble Ni concentration by soil properties. PMID:26217951

  3. Metals in European roadside soils and soil solution--a review.

    PubMed

    Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

    2014-06-01

    This review provides a summary of studies analysing metal concentrations in soils and soil solution at European roadsides. The data collected during 27 studies covering a total of 64 sites across a number of European countries were summarised. Highest median values of Cr, Cu, Ni, Pb, and Zn were determined in the top soil layer at the first 5 m beside the road. Generally, the influence of traffic on soil contamination decreased with increasing soil depth and distance to the road. The concentration patterns of metals in soil solution were independent from concentrations in the soil matrix. At 10-m distance, elevated soil metal concentrations, low pH, and low percolation rates led to high solute concentrations. Directly beside the road, high percolation rates lead to high annual loadings although solute concentrations are comparatively low. These loadings might be problematic, especially in regions with acidic sandy soils and a high groundwater table. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Effect of rainfall infiltration into unsaturated soil using soil column

    NASA Astrophysics Data System (ADS)

    Ibrahim, A.; Mukhlisin, M.; Jaafar, O.

    2018-02-01

    Rainfall especially in tropical region caused infiltration to the soil slope. The infiltration may change pore water pressure or matric suction of the soil. The event of rainfall infiltration into soil is a complex mechanism. Therefore, the main objectives of this research paper is to study the influence of rainfall intensity and duration that changed pore water pressure to soil. There are two types of soils used in this study; forest soil and kaolin. Soil column apparatus is used for experiments. Rainfall were applied to the soil and result for 3, 6, 12, 24, 72, 120 and 168 hours were retrieved. Result shows that for the both types of soil, the negative pore water pressures were increased during wetting process and gradually decreased towards drying process. The results also show that pore water pressure at top part was increased greatly as the wetting process started compared to the middle and bottom part of the column.

  5. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    Seybold, C. A.; Harms, D. S.; Grossman, R. B.

    2009-01-01

    Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

  6. Predicting radiocaesium sorption characteristics with soil chemical properties for Japanese soils.

    PubMed

    Uematsu, Shinichiro; Smolders, Erik; Sweeck, Lieve; Wannijn, Jean; Van Hees, May; Vandenhove, Hildegarde

    2015-08-15

    The high variability of the soil-to-plant transfer factor of radiocaesium (RCs) compels a detailed analysis of the radiocaesium interception potential (RIP) of soil, which is one of the specific factors ruling the RCs transfer. The range of the RIP values for agricultural soils in the Fukushima accident affected area has not yet been fully surveyed. Here, the RIP and other major soil chemical properties were characterised for 51 representative topsoils collected in the vicinity of the Fukushima contaminated area. The RIP ranged a factor of 50 among the soils and RIP values were lower for Andosols compared to other soils, suggesting a role of soil mineralogy. Correlation analysis revealed that the RIP was most strongly and negatively correlated to soil organic matter content and oxalate extractable aluminium. The RIP correlated weakly but positively to soil clay content. The slope of the correlation between RIP and clay content showed that the RIP per unit clay was only 4.8 mmol g(-1) clay, about threefold lower than that for clays of European soils, suggesting more amorphous minerals and less micaceous minerals in the clay fraction of Japanese soils. The negative correlation between RIP and soil organic matter may indicate that organic matter can mask highly selective sorption sites to RCs. Multiple regression analysis with soil organic matter and cation exchange capacity explained the soil RIP (R(2)=0.64), allowing us to map soil RIP based on existing soil map information. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Thermal-treated soil for mercury removal: Soil and phytotoxicity tests

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roh, Y.; Edwards, N.T.; Lee, S.Y.

    Mercury (Hg) contamination of soils and sediments is one of many environmental problems at the Oak Ridge Reservation, Oak Ridge, TN. Mercury-contaminated soil from the Lower East Fork Poplar Creek (LEFPC) at the Oak Ridge Reservation was treated thermally to reduce Hg concentration to a below target level (20 mg kg{sup {minus}1}) as a pilot scale thermal treatment demonstration. As a part of performance evaluation, the soil characteristics and plant growth response of the untreated and treated soil were examined. The soil treated at 350 C retained most of its original soil properties, but the soil treated at 600 Cmore » exhibited considerable changes in mineralogical composition and physicochemical characteristics. Growth and physiological response of the three plant species radish (Raphanus sativus L.), fescue (Festuca arundinacea Schreb.), and oat (Avena sativa L.) indicated adverse effects of the thermal treatment. The addition of N fertilizer had beneficial effects in the 350 C treated soil, but had little beneficial effect in the 600 C treated soil. Some changes of soil characteristics induced by thermal treatment cannot be avoided. Soil characteristics and phytotoxicity test results strongly suggest that changes occurring following the 350 C treatment do not limit the use of the treated soil to refill the excavated site for full-scale remediation. The only problem with the 350 C treatment is that small amounts of Hg compounds (<15 mg kg{sup {minus}1}) remain in the soil and a processing cost of $45/Mg.« less

  8. Exoenzyme activity in contaminated soils before and after soil washing: ß-glucosidase activity as a biological indicator of soil health.

    PubMed

    Chae, Yooeun; Cui, Rongxue; Woong Kim, Shin; An, Gyeonghyeon; Jeong, Seung-Woo; An, Youn-Joo

    2017-01-01

    It is essential to remediate or amend soils contaminated with various heavy metals or pollutants so that the soils may be used again safely. Verifying that the remediated or amended soils meet soil quality standards is an important part of the process. We estimated the activity levels of eight soil exoenzymes (acid phosphatase, arylsulfatase, catalase, dehydrogenase, fluorescein diacetate hydrolase, protease, urease, and ß-glucosidase) in contaminated and remediated soils from two sites near a non-ferrous metal smelter, using colorimetric and titrimetric determination methods. Our results provided the levels of activity of soil exoenzymes that indicate soil health. Most enzymes showed lower activity levels in remediated soils than in contaminated soils, with the exception of protease and urease, which showed higher activity after remediation in some soils, perhaps due to the limited nutrients available in remediated soils. Soil exoenzymes showed significantly higher activity in soils from one of the sites than from the other, due to improper conditions at the second site, including high pH, poor nutrient levels, and a high proportion of sand in the latter soil. Principal component analysis revealed that ß-glucosidase was the best indicator of soil ecosystem health, among the enzymes evaluated. We recommend using ß-glucosidase enzyme activity as a prior indicator in estimating soil ecosystem health. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Soil carbon dynamics

    NASA Astrophysics Data System (ADS)

    Trumbore, Susan; Barbosa de Camargo, Plínio

    The amount of organic carbon (C) stored in the upper meter of mineral soils in the Amazon Basin (˜40 Pg C) represents ˜3% of the estimated global store of soil carbon. Adding surface detrital C stocks and soil carbon deeper than 1 m can as much as quadruple this estimate. The potential for Amazon soil carbon to respond to changes in land use, climate, or atmospheric composition depends on the form and dynamics of soil carbon. Much (˜30% in the top ˜10 cm but >85% in soils to 1 m depth) of the carbon in mineral soils of the Oxisols and Ultisols that are the predominant soil types in the Amazon Basin is in forms that are strongly stabilized, with mean ages of centuries to thousands of years. Measurable changes in soil C stocks that accompany land use/land cover change occur in the upper meter of soil, although the presence of deep roots in forests systems drives an active C cycle at depths >1 m. Credible estimates of the potential for changes in Amazon soil C stocks with future land use and climate change are much smaller than predictions of aboveground biomass change. Soil organic matter influences fertility and other key soil properties, and thus is important independent of its role in the global C cycle. Most work on C dynamics is limited to upland soils, and more is needed to investigate C dynamics in poorly drained soils. Work is also needed to relate cycles of C with water, N, P, and other elements.

  10. Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

    NASA Astrophysics Data System (ADS)

    Ťupek, Boris; Ortiz, Carina A.; Hashimoto, Shoji; Stendahl, Johan; Dahlgren, Jonas; Karltun, Erik; Lehtonen, Aleksi

    2016-08-01

    Inaccurate estimate of the largest terrestrial carbon pool, soil organic carbon (SOC) stock, is the major source of uncertainty in simulating feedback of climate warming on ecosystem-atmosphere carbon dioxide exchange by process-based ecosystem and soil carbon models. Although the models need to simplify complex environmental processes of soil carbon sequestration, in a large mosaic of environments a missing key driver could lead to a modeling bias in predictions of SOC stock change.We aimed to evaluate SOC stock estimates of process-based models (Yasso07, Q, and CENTURY soil sub-model v4) against a massive Swedish forest soil inventory data set (3230 samples) organized by a recursive partitioning method into distinct soil groups with underlying SOC stock development linked to physicochemical conditions.For two-thirds of measurements all models predicted accurate SOC stock levels regardless of the detail of input data, e.g., whether they ignored or included soil properties. However, in fertile sites with high N deposition, high cation exchange capacity, or moderately increased soil water content, Yasso07 and Q models underestimated SOC stocks. In comparison to Yasso07 and Q, accounting for the site-specific soil characteristics (e. g. clay content and topsoil mineral N) by CENTURY improved SOC stock estimates for sites with high clay content, but not for sites with high N deposition.Our analysis suggested that the soils with poorly predicted SOC stocks, as characterized by the high nutrient status and well-sorted parent material, indeed have had other predominant drivers of SOC stabilization lacking in the models, presumably the mycorrhizal organic uptake and organo-mineral stabilization processes. Our results imply that the role of soil nutrient status as regulator of organic matter mineralization has to be re-evaluated, since correct SOC stocks are decisive for predicting future SOC change and soil CO2 efflux.

  11. SoilGrids1km — Global Soil Information Based on Automated Mapping

    PubMed Central

    Hengl, Tomislav; de Jesus, Jorge Mendes; MacMillan, Robert A.; Batjes, Niels H.; Heuvelink, Gerard B. M.; Ribeiro, Eloi; Samuel-Rosa, Alessandro; Kempen, Bas; Leenaars, Johan G. B.; Walsh, Markus G.; Gonzalez, Maria Ruiperez

    2014-01-01

    Background Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. Methodology/Principal Findings We present SoilGrids1km — a global 3D soil information system at 1 km resolution — containing spatial predictions for a selection of soil properties (at six standard depths): soil organic carbon (g kg−1), soil pH, sand, silt and clay fractions (%), bulk density (kg m−3), cation-exchange capacity (cmol+/kg), coarse fragments (%), soil organic carbon stock (t ha−1), depth to bedrock (cm), World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles), and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images), lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database). Prediction accuracies assessed using 5–fold cross-validation were between 23–51%. Conclusions/Significance SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1) weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2) difficulty to obtain covariates that capture soil forming factors, (3) low sampling density and spatial clustering of soil profile locations. However, as the Soil

  12. Chemical evaluation of soil-solution in acid forest soils

    USGS Publications Warehouse

    Lawrence, G.B.; David, M.B.

    1996-01-01

    Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters.This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of New York. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally < 15%), (ii) variations in the length of reaction-time did not affect expelled solution concentrations, and (iii) adding and expelling solution did not cause detectable changes in soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and

  13. Connecting soil microbial communities to soil functioning and soil health

    USDA-ARS?s Scientific Manuscript database

    One of the most important functions soils perform, is the capacity to buffer anthropogenic disturbances to sustain productivity while improving water and air quality. At the core of a healthy soil is a biological active and diverse community that provides internal nutrient cycling and is resilient t...

  14. The Soil Model Development and Intercomparison Panel (SoilMIP) of the International Soil Modeling Consortium (ISMC)

    NASA Astrophysics Data System (ADS)

    Vanderborght, Jan; Priesack, Eckart

    2017-04-01

    The Soil Model Development and Intercomparison Panel (SoilMIP) is an initiative of the International Soil Modeling Consortium. Its mission is to foster the further development of soil models that can predict soil functions and their changes (i) due to soil use and land management and (ii) due to external impacts of climate change and pollution. Since soil functions and soil threats are diverse but linked with each other, the overall aim is to develop holistic models that represent the key functions of the soil system and the links between them. These models should be scaled up and integrated in terrestrial system models that describe the feedbacks between processes in the soil and the other terrestrial compartments. We propose and illustrate a few steps that could be taken to achieve these goals. A first step is the development of scenarios that compare simulations by models that predict the same or different soil services. Scenarios can be considered at three different levels of comparisons: scenarios that compare the numerics (accuracy but also speed) of models, scenarios that compare the effect of differences in process descriptions, and scenarios that compare simulations with experimental data. A second step involves the derivation of metrics or summary statistics that effectively compare model simulations and disentangle parameterization from model concept differences. These metrics can be used to evaluate how more complex model simulations can be represented by simpler models using an appropriate parameterization. A third step relates to the parameterization of models. Application of simulation models implies that appropriate model parameters have to be defined for a range of environmental conditions and locations. Spatial modelling approaches are used to derive parameter distributions. Considering that soils and their properties emerge from the interaction between physical, chemical and biological processes, the combination of spatial models with process

  15. Soil Tillage as a Factor of Soil Conservation

    NASA Astrophysics Data System (ADS)

    Sherer, D. V.; Chumanova, N. N.

    2017-05-01

    The work describes the question of the soil treatment system influence on agro-physical and microbiological properties of gray forest soils, and yield of barley in Western Siberia. Research works were carried out in 2013-2014 in Yaya region of the Kemerovo region. Tillage affects soil structure. The water stability in zero tillage conditions was poor (15.7%). Soil density corresponding to the optimum rate for barley is formed by the zonal processing system, while at the zero tillage soil remains solid. The best indicators of phosphataze, catalysis and amylase activity are formed with minimum processing system. In the experiment the highest yield of barley was obtained with minimum tillage - 12.1 c/ha.

  16. Soil Organic Matter and Soil Productivity: Searching for the Missing Link

    Treesearch

    Felipe G. Sanchez

    1998-01-01

    Soil-organic matter (SOM) is a complex array of components including soil fauna and flora at different stages of decomposition (Berg et al., 1982). Its concentration in soils can vary from 0.5% in mineral soils to almost 100% in peat soils (Brady, 1974). Organic matter (OM) in the surface mineral soil is considered a major determinant of forest ecosystem productivity...

  17. Facilitated transport in European soils from the Euro-soil project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dolfing, J.; Scheltens, S.D.

    1999-07-01

    The authors studied the response of five reference soils from the European Union (a vertic cambisol, rendzina, dystric cambisol, orthic luvisol, and orthic podzol, also known as Euro-soils 1 to 5) to the addition of HCl and NaOH. For all soils, which were incubated as soil slurries, the amount of organic carbon in solution remained essentially constant upon addition of HCl but increased upon addition of NaOH; that is, it was not the pH of the soil that determined changes in the solubilization of dissolved organic carbon but {Delta}pH. This observation has implications for the design of active soil managementmore » strategies, because increased amounts of dissolved organic carbon in the soil solution pose a risk for leaching of contaminants to deeper soil layers and eventually to the groundwater. In the past, much attention has been paid to the reaction of soils to acidification and changing land use as practiced when agricultural land is taken out of production. The observations reported here indicate that soil alkalization is not necessarily without environmental and toxicological risks.« less

  18. Soil microbial respiration from various microhabitats in Arctic landscape: impact of soil type, environmental conditions and soil age

    NASA Astrophysics Data System (ADS)

    Biasi, Christina; Jokinen, Simo; Marushchak, Maija; Trubnikova, Tatiana; Hämäläinen, Kai; Oinonen, Markku; Martikainen, Pertti

    2014-05-01

    Soil respiration is the second largest C flux between atmosphere and terrestrial ecosystems after gross primary production. Carbon dioxide released from soils is thus a major contributor to the atmospheric CO2 concentration. Despite the global importance, soil respiration and its components (heterotrophic and autotrophic respiration) remain poorly understood and not well constrained fluxes of the terrestrial C cycle. This is particularly true for the Arctic, where huge amounts of the Earth's soil carbon is stored. Here, we report on heterotrophic soil respiration rates from various Arctic tundra microhabitats measured in situ. The study site was Seida (67°07'N, 62°57'E, 100 m a.s.l.) which is characterized by typical sub-arctic permafrost landscape which comprises raised, vegetated permafrost peat plateaus, interspersed with spots of bare peat surfaces (peat circles), and upland mineral soils. We used isotope partitioning approach based on differences in natural abundance of 14C between soil and plants to separate sources of soil-respired CO2. In addition, the tradition trenching approach was employed. Complementary laboratory incubations with homogenized soil were conducted to assess primary decomposability of the soils and to identify age of the CO2 released and thus get more information on the nature of the sources of respiration. The major aim was to link SMR rates with of soil type, land cover class, soil physic-chemical properties (e.g. water content), soil C stocks and age of soil. Results show that, despite profound differences in soil characteristics and primary decomposability of organic matter, surface CO2 fluxes derived from soil microbial respiration rates were rather similar between microhabitats. The only factor which influenced, at least to some extent, the respiration rates was total soil C (and N) stocks in surface soils. There was some evidence for reduced soil-related CO2 emissions from peatlands, though results were not consistent between the

  19. Effect of Soil Washing for Lead and Zinc Removal on Soil Hydraulic Properties

    NASA Astrophysics Data System (ADS)

    Kammerer, Gerhard; Zupanc, Vesna; Gluhar, Simon; Lestan, Domen

    2017-04-01

    Soil washing as a metal pollution remediation process, especially part with intensive mixing of the soil slurry and soil compression after de-watering, significantly deteriorates physical properties of soil compared to those of non-remediated soil. Furthermore, changed physical characteristics of remediated soil influence interaction of plant roots with soil system and affect soil water regime. Remediated soils showed significant differences to their original state in water retention properties and changed structure due to the influence of artificial structure created during remediation process. Disturbed and undisturbed soil samples of remediated and original soils were analyzed. We evaluated soil hydraulic properties as a possible constraint for re-establishing soil structure and soil fertility after the remediation procedure.

  20. Soil Characteristics Driving Arbuscular Mycorrhizal Fungal Communities in Semiarid Mediterranean Soils

    PubMed Central

    Torres, Maria Pilar; Montesinos-Navarro, Alicia; Roldán, Antonio

    2016-01-01

    ABSTRACT We investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil of Brachypodium retusum in six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations. IMPORTANCE Communities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels

  1. Soil Characteristics Driving Arbuscular Mycorrhizal Fungal Communities in Semiarid Mediterranean Soils.

    PubMed

    Alguacil, Maria Del Mar; Torres, Maria Pilar; Montesinos-Navarro, Alicia; Roldán, Antonio

    2016-06-01

    We investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil of Brachypodium retusum in six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations. Communities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels) were the main factors

  2. Effects of drought on forest soil structure and hydrological soil functions

    NASA Astrophysics Data System (ADS)

    Gimbel, K.; Puhlmann, H.; Weiler, M.

    2012-04-01

    Climate change is predicted to severely affect precipitation patterns across central Europe. Soil structure is closely linked to the activity of soil microbiota and plant roots, which modify flow pathways along roots, organic matter and water repellence of soils. Through shrinkage and fracturing of soil aggregates, soil structure is also responding to changing climate (in particular drought) conditions. We investigate the possible effects on biogeochemical and hydropedological processes in response to predicted future reduced precipitation, and the interaction of these processes with the biodiversity of the forest understorey and soil biota. The hypotheses of this study are: (i) drought causes a change in soil structure, which affects hydrological soil functions (water infiltration, uptake and redistribution); (ii) changes in rooting patterns and microbial community composition, in response to drought, influence the hydrological soil functions. To test our hypotheses, we built adaptive roofing systems on nine sites in Germany, which allow a flexible reduction of precipitation in order to achieve the long-term minimum precipitation of a site. Here we present first measurements of our repeated measuring/sampling campaign, which will be conducted over a period of three years. The aim of our experiments is to analyze soil pore architecture and related flow and transport behaviour with dye tracer sprinkling experiments, soil column experiments with stable isotope (deuterium, oxygen-18) enriched water, computed tomography at soil monoliths (~70 l) and multi-step outflow experiments with 100 ml soil cores. Finally, we sketch our idea how to relate the observed temporal changes of soil structure and hydrological soil functions to the observed dynamics of hydrometeorological site conditions, soil moisture and desiccation as well as changes in rooting patterns, herb layer and soil microbiotic communities. The results of this study may help to assess future behavior of the

  3. Soil organic carbon response to shrub encroachment regulated by soil aggregates

    NASA Astrophysics Data System (ADS)

    Zhu, Y.; Li, H.; Shen, H.; Feng, Y.; Fang, J.

    2017-12-01

    Shrub encroachment leads to change in soil organic carbon content, but there still exists a lot of uncertainty in its mechanism as it relates to deep soil research. Soil organic carbon is usually associated with stable aggregate quantity. In this study, we conducted a field investigation for typical steppe and desert steppe in Inner Mongolia with the view to examining the impact of shrub encroachment on soil organic carbon with soil aggregate at a depth of 0-500 cm. The results show that in the desert steppe, the particle size of soil aggregate content level in different depth are presented the trend of shrub patches is lower than the herb matrix, organic carbon content of soil aggregate under 50 cm deeper presents the trend of shrub patches is higher than herb matrix, eventually leading to shrub patches whole soil organic carbon in the 0 to 50 cm depth lower than the herb matrix, and in deeper soil below 50 cm higher than the herb matrix. In the typical steppe, there is no significant difference between soil aggregate structure of shrub patches and herb matrix, but organic carbon content of soil aggregate, especially large aggregate organic carbon content in the shrub patches is significantly higher than the herb matrix, so that the whole soil organic carbon content in the shrub patches is significantly higher than herb matrix. The rate of soil organic carbon content change (0-100 cm) by shrub encroachment showed significant negative correlation with the mean weight diameter of soil aggregate of herb matrix. We also found that the variations of soil organic carbon in desert steppe is not dominant by aggregates of some size, but the change of the typical steppe soil organic carbon mainly contributed by > 0.25 mm and 0.053-0.25 mm aggregates. The results suggested that the effects of shrub encroachment on soil organic carbon is regulated by soil aggregate, but it is varied for different type of grassland, which should provide some insights into our understanding on

  4. Effects of imidacloprid on soil microbial communities in different saline soils.

    PubMed

    Zhang, Qingming; Xue, Changhui; Wang, Caixia

    2015-12-01

    The effects of imidacloprid in the soil environment are a worldwide concern. However, the impact of imidacloprid on soil microorganisms under salt stress is almost unknown. Therefore, an indoor incubation test was performed, and the denaturing gradient gel electrophoresis (DGGE) approach was used to determine the response of different saline soil bacterial and fungal community structures to the presence of imidacloprid (0.4, 2, 10 mg kg(-1)). The results showed that the soil bacterial diversity slightly declined with increasing imidacloprid concentration in soils with low salinity. In moderately saline soils, a new band in the DGGE profile suggested that imidacloprid could improve the soil bacterial diversity to some degree. An analysis of variance indicated that the measured soil bacterial diversity parameters were significantly affected by dose and incubation time. Compared with the control, the soil fungal community structure showed no obvious changes in low and moderately saline soils treated with imidacloprid. The results of these observations provide a basic understanding of the potential ecological effects of imidacloprid on different microorganisms in saline soils.

  5. Environmental Controls of Soil Organic Carbon in Soils Across Amazonia

    NASA Astrophysics Data System (ADS)

    Quesada, Carlos Alberto; Paz, Claudia; Phillips, Oliver; Nonato Araujo Filho, Raimundo; Lloyd, Jon

    2015-04-01

    Amazonian forests store and cycle a significant amount of carbon on its soils and vegetation. Yet, Amazonian forests are now subject to strong environmental pressure from both land use and climate change. Some of the more dramatic model projections for the future of the Amazon predict a major change in precipitation followed by savanization of most currently forested areas, resulting in major carbon losses to the atmosphere. However, how soil carbon stocks will respond to climatic and land use changes depend largely on how soil carbon is stabilized. Amazonian soils are highly diverse, being very variable in their weathering levels and chemical and physical properties, and thus it is important to consider how the different soils of the Basin stabilize and store soil organic carbon (SOC). The wide variation in soil weathering levels present in Amazonia, suggests that soil groups with contrasting pedogenetic development should differ in their predominant mechanism of SOC stabilization. In this study we investigated the edaphic, mineralogical and climatic controls of SOC concentration in 147 pristine forest soils across nine different countries in Amazonia, encompassing 14 different WRB soil groups. Soil samples were collected in 1 ha permanent plots used for forest dynamics studies as part of the RAINFOR project. Only 0-30 cm deep averages are reported here. Soil samples were analyzed for carbon and nitrogen and for their chemical (exchangeable bases, phosphorus, pH) and physical properties, (particle size, bulk density) and mineralogy through standard selective dissolution techniques (Fe and Al oxides) and by semi-quantitative X-Ray diffraction. In Addition, selected soils from each soil group had SOC fractionated by physical and chemical techniques. Our results indicate that different stabilization mechanisms are responsible for SOC stabilization in Amazonian soils with contrasting pedogenetic level. Ferralsols and Acrisols were found to have uniform mineralogy

  6. Proximal soil sensing and sensor fusion for soil health assessment

    USDA-ARS?s Scientific Manuscript database

    Assessment of soil health involves determining how well a soil is performing its biological, chemical, and physical functions relative to its inherent potential. Due to high costs, labor requirements, and soil disturbance, traditional laboratory analyses cannot provide high resolution soil health da...

  7. know Soil Know Life - Getting Kids Excited About Soils

    NASA Astrophysics Data System (ADS)

    Lindbo, David L.; Robinson, Clay; Kozlowski, Deborah

    2014-05-01

    In the United States soils are often taught in primary school (grade 3-6) but with little excitement or passion. We have been working with schools and teachers to bring our passion about soils to this audience. The methods and message can be conveyed simply and effectively by engaging the students in a dialog and through kinematic learning. Our approach is to begin with a simple question - what are 4 things we cannot live without. The answer - Air, Water, Sunlight, and Soil. Most students say "food, shelter, clothing, plants, animals etc." so we then explain all of those come from soil. This leads us to a quick "dance" illustrating that without soils we would be 'Hungry. Homeless, and Naked". The results are that students and teachers remember this simple message. From this point it is our hope that students will continue to understand the importance of soils and stop treating soils like dirt. Other simple exercises for this younger audience will also be presented.

  8. Relation between L-band soil emittance and soil water content

    NASA Technical Reports Server (NTRS)

    Stroosnijder, L.; Lascano, R. J.; Van Bavel, C. H. M.; Newton, R. W.

    1986-01-01

    An experimental relation between soil emittance (E) at L-band and soil surface moisture content (M) is compared with a theoretical one. The latter depends on the soil dielectric constant, which is a function of both soil moisture content and of soil texture. It appears that a difference of 10 percent in the surface clay content causes a change in the estimate of M on the order of 0.02 cu m/cu m. This is based on calculations with a model that simulates the flow of water and energy, in combination with a radiative transfer model. It is concluded that an experimental determination of the E-M relation for each soil type is not required, and that a rough estimate of the soil texture will lead to a sufficiently accurate estimate of soil moisture from a general, theoretical relationship obtained by numerical simulation.

  9. Influence of Herbicide Triasulfuron on Soil Microbial Community in an Unamended Soil and a Soil Amended with Organic Residues

    PubMed Central

    Pose-Juan, Eva; Igual, José M.; Sánchez-Martín, María J.; Rodríguez-Cruz, M. S.

    2017-01-01

    The effect of organic amendments and pesticides on a soil microbial community has garnered considerable interest due to the involvement of microorganisms in numerous soil conservation and maintenance reactions. The aim of this work was to assess the influence on a soil microbial community of the simultaneous application of the herbicide triasulfuron at three doses (2, 10, and 50 mg kg-1), with an organic amendment [sewage sludge (SS) or green compost (GC)]. Dissipation kinetics, soil microbial biomass, dehydrogenase activity (DHA) and respiration, and the profile of phospholipid fatty acids (PLFAs) extracted from the soil, were determined in unamended (S) soil and amended (S+SS and S+GC) ones. Triasulfuron dissipation followed the single first-order kinetics model. Half-life (DT50) values were higher in the amended soils than in the unamended one for the 10 and 50 mg kg-1 doses. The dissipation rates were lower in the S+GC soil for the three herbicide doses applied. In general, soil biomass, DHA and respiration values increased in SS- and GC-amended soils compared to the unamended one. DHA values decreased (S and S+SS) or increased (S+GC) with the incubation time of soil with herbicide at the different doses applied. Respiration values increased with the herbicide doses applied and decreased with the incubation time, although maximum values were obtained for soils treated with the highest dose after 70 days of incubation. PLFA analysis indicated different effects of triasulfuron on the soil microbial community structure depending on the organic amendments. While the increasing triasulfuron doses resulted in deeper alterations in the S soil, the time after triasulfuron application was the most important variation in the S+SS and S+GC soils. The overall results indicate that the soil amendment has an effect on herbicide dissipation rate and the soil microbial community. Initially, a high dose of triasulfuron had detrimental effects on the soil microbial community

  10. Relationship between soil erodibility and modeled infiltration rate in different soils

    NASA Astrophysics Data System (ADS)

    Wang, Guoqiang; Fang, Qingqing; Wu, Binbin; Yang, Huicai; Xu, Zongxue

    2015-09-01

    The relationship between soil erodibility, which is hard to measure, and modeled infiltration rate were rarely researched. Here, the soil erodibility factors (K and Ke in the USLE, Ki and K1 in the WEPP) were calculated and the infiltration rates were modeled based on the designed laboratory simulation experiments and proposed infiltration model, in order to build their relationship. The impacts of compost amendment on the soil erosion characteristics and relationship were also studied. Two contrasting agricultural soils (bare and cultivated fluvo-aquic soils) were used, and different poultry compost contents (control, low and high) were applied to both soils. The results indicated that the runoff rate, sediment yield rate and soil erodibility of the bare soil treatments were generally higher than those of the corresponding cultivated soil treatments. The application of composts generally decreased sediment yield and soil erodibility but did not always decrease runoff. The comparison of measured and modeled infiltration rates indicated that the model represented the infiltration processes well with an N-S coefficient of 0.84 for overall treatments. Significant negative logarithmic correlations have been found between final infiltration rate (FIR) and the four soil erodibility factors, and the relationship between USLE-K and FIR demonstrated the best correlation. The application of poultry composts would not influence the logarithmic relationship between FIR and soil erodibility. Our study provided a useful tool to estimate soil erodibility.

  11. Linking soil bacterial biodiversity and soil carbon stability.

    PubMed

    Mau, Rebecca L; Liu, Cindy M; Aziz, Maliha; Schwartz, Egbert; Dijkstra, Paul; Marks, Jane C; Price, Lance B; Keim, Paul; Hungate, Bruce A

    2015-06-01

    Native soil carbon (C) can be lost in response to fresh C inputs, a phenomenon observed for decades yet still not understood. Using dual-stable isotope probing, we show that changes in the diversity and composition of two functional bacterial groups occur with this 'priming' effect. A single-substrate pulse suppressed native soil C loss and reduced bacterial diversity, whereas repeated substrate pulses stimulated native soil C loss and increased diversity. Increased diversity after repeated C amendments contrasts with resource competition theory, and may be explained by increased predation as evidenced by a decrease in bacterial 16S rRNA gene copies. Our results suggest that biodiversity and composition of the soil microbial community change in concert with its functioning, with consequences for native soil C stability.

  12. Effect of soil acidity, soil strength and macropores on root growth and morphology of perennial grass species differing in acid-soil resistance.

    PubMed

    Haling, Rebecca E; Simpson, Richard J; Culvenor, Richard A; Lambers, Hans; Richardson, Alan E

    2011-03-01

    It is unclear whether roots of acid-soil resistant plants have significant advantages, compared with acid-soil sensitive genotypes, when growing in high-strength, acid soils or in acid soils where macropores may allow the effects of soil acidity and strength to be avoided. The responses of root growth and morphology to soil acidity, soil strength and macropores by seedlings of five perennial grass genotypes differing in acid-soil resistance were determined, and the interaction of soil acidity and strength for growth and morphology of roots was investigated. Soil acidity and strength altered root length and architecture, root hair development, and deformed the root tip, especially in acid-soil sensitive genotypes. Root length was restricted to some extent by soil acidity in all genotypes, but the adverse impact of soil acidity on root growth by acid-soil resistant genotypes was greater at high levels of soil strength. Roots reacted to soil acidity when growing in macropores, but elongation through high-strength soil was improved. Soil strength can confound the effect of acidity on root growth, with the sensitivity of acid-resistant genotypes being greater in high-strength soils. This highlights the need to select for genotypes that resist both acidity and high soil strength. © 2010 Blackwell Publishing Ltd.

  13. Soil cover patterns influence on the land environmental functions, agroecological quality, land-use and monitoring efficiency in the Central Russia

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan; Yashin, Ivan; Lukin, Sergey; Valentini, Riccardo

    2015-04-01

    current practice versions. Well-elaborated monitoring collaboration with the principal natural reserves in south-taiga and forest-steppe zones provides process-based interaction with long-term data on zonal climatic, landscape and soil features necessary to test the process, functional and evaluation models in the specific conditions of each bioclimatic zone. The dominated erosion and dehumification trends have been essentially activated for last 3-4 decades due to hu¬mus negative balance around 0.6-0.7 t ha-1year-1 and connected disaggregation with annual rate between 1 and 25 g/kg for aggregates 10-0.25 mm. "Standard" monitoring objects and regionally generalized data showed characteristic for Chernozems 2-2.5 % humus drop during this period and active processes of CO2 emission and humus eluvial-illuvial profile redistribution too. Forest-steppe Chernozems are usually characterized by higher stability than steppe ones. The ratio between erosive and biological losses in humus stock can be ten¬tatively estimated as fifty-fifty with essential variability within slope landscape. Both these processes have essential impacts on different sets of soil environmental and agroecological functions (including atmospheric air, surface and ground water quality, biodiversity and profitability) that we need to understand and predict. A drop of humus content below threshold values (for different soils between 1.5 and 6%) considerably reduces not only soil environmental regulation functions but also effectiveness of used fertilizers, crop yield quality and possibility of sustainable agricultural land-use. The carried out long-term researches of representative natural, rural and urban landscapes in Tver, Yaroslavl, Vladimir, Moscow, Kaluga, Kursk, Belgorod, Tambov, Voronezh and Saratov regions give us validation and ranging of the limiting factors of the elementary soil cover patterns current features and transformation processes, environmental functions and agroecological quality

  14. [Interrelationships between soil fauna and soil environmental factors in China: research advance].

    PubMed

    Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

    2010-09-01

    Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.

  15. The impact of soil degradation on soil functioning in Europe

    NASA Astrophysics Data System (ADS)

    Montanarella, Luca

    2010-05-01

    The European Commission has presented in September 2006 its Thematic Strategy for Soil Protection.The Thematic Strategy for Soil Protection consists of a Communication from the Commission to the other European Institutions, a proposal for a framework Directive (a European law), and an Impact Assessment. The Communication (COM(2006) 231) sets the frame. It defines the relevant soil functions for Europe and identifies the major threats. It explains why further action is needed to ensure a high level of soil protection, sets the overall objective of the Strategy and explains what kind of measures must be taken. It establishes a ten-year work program for the European Commission. The proposal for a framework Directive (COM(2006) 232) sets out common principles for protecting soils across the EU. Within this common framework, the EU Member States will be in a position to decide how best to protect soil and how use it in a sustainable way on their own territory. The Impact Assessment (SEC (2006) 1165 and SEC(2006) 620) contains an analysis of the economic, social and environmental impacts of the different options that were considered in the preparatory phase of the strategy and of the measures finally retained by the Commission. Since 2006 a large amount of new evidence has allowed to further document the extensive negative impacts of soil degradation on soil functioning in Europe. Extensive soil erosion, combined with a constant loss of soil organic carbon, have raised attention to the important role soils are playing within the climate change related processes. Other important processes are related to the loss of soil biodiversity, extensive soil sealing by housing and infrastructure, local and diffuse contamination by agricultural and industrial sources, compaction due to unsustainable agricultural practices and salinization by unsustainable irrigation practices. The extended impact assessment by the European Commission has attempted to quantify in monetary terms the

  16. Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions.

    PubMed

    Luo, Zhongkui; Feng, Wenting; Luo, Yiqi; Baldock, Jeff; Wang, Enli

    2017-10-01

    Soil organic carbon (SOC) dynamics are regulated by the complex interplay of climatic, edaphic and biotic conditions. However, the interrelation of SOC and these drivers and their potential connection networks are rarely assessed quantitatively. Using observations of SOC dynamics with detailed soil properties from 90 field trials at 28 sites under different agroecosystems across the Australian cropping regions, we investigated the direct and indirect effects of climate, soil properties, carbon (C) inputs and soil C pools (a total of 17 variables) on SOC change rate (r C , Mg C ha -1  yr -1 ). Among these variables, we found that the most influential variables on r C were the average C input amount and annual precipitation, and the total SOC stock at the beginning of the trials. Overall, C inputs (including C input amount and pasture frequency in the crop rotation system) accounted for 27% of the relative influence on r C , followed by climate 25% (including precipitation and temperature), soil C pools 24% (including pool size and composition) and soil properties (such as cation exchange capacity, clay content, bulk density) 24%. Path analysis identified a network of intercorrelations of climate, soil properties, C inputs and soil C pools in determining r C . The direct correlation of r C with climate was significantly weakened if removing the effects of soil properties and C pools, and vice versa. These results reveal the relative importance of climate, soil properties, C inputs and C pools and their complex interconnections in regulating SOC dynamics. Ignorance of the impact of changes in soil properties, C pool composition and C input (quantity and quality) on SOC dynamics is likely one of the main sources of uncertainty in SOC predictions from the process-based SOC models. © 2017 John Wiley & Sons Ltd.

  17. Soil aggregate and organic carbon distribution at dry land soil and paddy soil: the role of different straws returning.

    PubMed

    Huang, Rong; Lan, Muling; Liu, Jiang; Gao, Ming

    2017-12-01

    Agriculture wastes returning to soil is one of common ways to reuse crop straws in China. The returned straws are expected to improve the fertility and structural stability of soil during the degradation of straw it selves. The in situ effect of different straw (wheat, rice, maize, rape, and broad bean) applications for soil aggregate stability and soil organic carbon (SOC) distribution were studied at both dry land soil and paddy soil in this study. Wet sieving procedures were used to separate soil aggregate sizes. Aggregate stability indicators including mean weight diameter, geometric mean diameter, mean weight of specific surface area, and the fractal dimension were used to evaluate soil aggregate stability after the incubation of straws returning. Meanwhile, the variation and distribution of SOC in different-sized aggregates were further studied. Results showed that the application of straws, especially rape straw at dry land soil and rice straw at paddy soil, increased the fractions of macro-aggregate (> 0.25 mm) and micro-aggregate (0.25-0.053 mm). Suggesting the nutrients released from straw degradation promotes the growing of soil aggregates directly and indirectly. The application of different straws increased the SOC content at both soils and the SOC mainly distributed at < 0.53 mm aggregates. However, the contribution of SOC in macro- and micro-aggregates increased. Straw-applied paddy soil have a higher total SOC content but lower SOC contents at > 0.25 and 0.25-0.053 mm aggregates with dry land soil. Rape straw in dry land and rice straw in paddy field could stabilize soil aggregates and increasing SOC contents best.

  18. [Landscape and zonal distribution of bloodsucking mosquitoes and horse flies (Diptera: Culicidae, Tabanidae) in the northeastern Russian Plain].

    PubMed

    Pestov, S V; Paniukova, E V

    2013-01-01

    The data on the distribution of 34 species of bloodsucking mosquitoes and on 42 horsefly species of the fauna of the northeastern Russian Plain are given. The analysis of the landscape and zonal changes in species diversity and their abundance was performed. Species diversity of these families increased northwards. Two borders of the fauna's depletion were discovered: at the border between the middle and northern taiga subzones (mosquitoes and horseflies) and at the border between the northernmost taiga subzone and the forest-tundra zone (horseflies only). The northern and southern boundaries of species ranges in the region are identified.

  19. Effects of Tillage Practices on Soil Organic Carbon and Soil Respiration

    NASA Astrophysics Data System (ADS)

    Rusu, Teodor; Ioana Moraru, Paula; Bogdan, Ileana; Ioan Pop, Adrian

    2016-04-01

    Soil tillage system and its intensity modify by direct and indirect action soil temperature, moisture, bulk density, porosity, penetration resistance and soil structural condition. Minimum tillage and no-tillage application reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first years of application. The degree of compaction is directly related to soil type and its state of degradation. All this physicochemical changes affect soil biology and soil respiration. Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil respiration is one measure of biological activity and decomposition. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant and fertilizer. Our research follows the effects of the three tillage systems: conventional system, minimum tillage and no-tillage on soil respiration and finally on soil organic carbon on rotation soybean - wheat - maize, obtained on an Argic Faeoziom from the Somes Plateau, Romania. To quantify the change in soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest). Soil monitoring system of CO2 and O2 included gradient method, made by using a new generation of sensors capable of measuring CO2 concentration in-situ and quasi-instantaneous in gaseous phase. At surface soil respiration is made by using ACE Automated Soil CO2 Exchange System. These areas were was our research presents a medium multi annual temperature of 8.20C medium of multi annual rain drowns: 613 mm. The experimental variants chosen were: i). Conventional system: reversible plough (22-25 cm) + rotary grape (8-10 cm); ii). Minimum tillage system: paraplow (18-22 cm) + rotary grape (8-10 cm); iii). No-tillage. The experimental design was a split-plot design with three

  20. A long-term soil structure observatory for post-compaction soil structure evolution: design and initial soil structure recovery observations

    NASA Astrophysics Data System (ADS)

    Keller, Thomas; Colombi, Tino; Ruiz, Siul; Grahm, Lina; Reiser, René; Rek, Jan; Oberholzer, Hans-Rudolf; Schymanski, Stanislaus; Walter, Achim; Or, Dani

    2016-04-01

    Soil compaction due to agricultural vehicular traffic alters the geometrical arrangement of soil constituents, thereby modifying mechanical properties and pore spaces that affect a range of soil hydro-ecological functions. The ecological and economic costs of soil compaction are dependent on the immediate impact on soil functions during the compaction event, and a function of the recovery time. In contrast to a wealth of soil compaction information, mechanisms and rates of soil structure recovery remain largely unknown. A long-term (>10-yr) soil structure observatory (SSO) was established in 2014 on a loamy soil in Zurich, Switzerland, to quantify rates and mechanisms of structure recovery of compacted arable soil under different post-compaction management treatments. We implemented three initial compaction treatments (using a two-axle agricultural vehicle with 8 Mg wheel load): compaction of the entire plot area (i.e. track-by-track), compaction in wheel tracks, and no compaction. After compaction, we implemented four post-compaction soil management systems: bare soil (BS), permanent grass (PG), crop rotation without mechanical loosening (NT), and crop rotation under conventional tillage (CT). BS and PG provide insights into uninterrupted natural processes of soil structure regeneration under reduced (BS) and normal biological activity (PG). The two cropping systems (NT and CT) enable insights into soil structure recovery under common agricultural practices with minimal (NT) and conventional mechanical soil disturbance (CT). Observations include periodic sampling and measurements of soil physical properties, earthworm abundance, crop measures, electrical resistivity and ground penetrating radar imaging, and continuous monitoring of state variables - soil moisture, temperature, CO2 and O2 concentrations, redox potential and oxygen diffusion rates - for which a network of sensors was installed at various depths (0-1 m). Initial compaction increased soil bulk density

  1. Soil organic carbon and nitrogen pools drive soil C-CO2 emissions from selected soils in Maritime Antarctica.

    PubMed

    Pires, C V; Schaefer, C E R G; Hashigushi, A K; Thomazini, A; Filho, E I F; Mendonça, E S

    2017-10-15

    The ongoing trend of increasing air temperatures will potentially affect soil organic matter (SOM) turnover and soil C-CO 2 emissions in terrestrial ecosystems of Maritime Antarctica. The effects of SOM quality on this process remain little explored. We evaluated (i) the quantity and quality of soil organic matter and (ii) the potential of C release through CO 2 emissions in lab conditions in different soil types from Maritime Antarctica. Soil samples (0-10 and 10-20cm) were collected in Keller Peninsula and the vicinity of Arctowski station, to determine the quantity and quality of organic matter and the potential to emit CO 2 under different temperature scenarios (2, 5, 8 and 11°C) in lab. Soil organic matter mineralization is low, especially in soils with low organic C and N contents. Recalcitrant C form is predominant, especially in the passive pool, which is correlated with humic substances. Ornithogenic soils had greater C and N contents (reaching to 43.15gkg -1 and 5.22gkg -1 for total organic carbon and nitrogen, respectively). C and N were more present in the humic acid fraction. Lowest C mineralization was recorded from shallow soils on basaltic/andesites. C mineralization rates at 2°C were significant lower than at higher temperatures. Ornithogenic soils presented the lowest values of C-CO 2 mineralized by g of C. On the other hand, shallow soils on basaltic/andesites were the most sensitive sites to emit C-CO 2 by g of C. With permafrost degradation, soils on basaltic/andesites and sulfates are expected to release more C-CO 2 than ornithogenic soils. With greater clay contents, more protection was afforded to soil organic matter, with lower microbial activity and mineralization. The trend of soil temperature increases will favor C-CO 2 emissions, especially in the reduced pool of C stored and protected on permafrost, or in occasional Histosols. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Soils in Schools: Embedding Soil Science in STEM

    ERIC Educational Resources Information Center

    Bryce, Alisa

    2015-01-01

    Soil science, though relevant to a variety of subjects including science, geography, mathematics, social sciences and history, is typically perceived as a subgenre of agriculture. With a global need for soil scientists, and declining numbers in university soil courses, there's a growing gap between science needs and providers. One way to promote…

  3. Effect of soil texture on phytoremediation of arsenic-contaminated soils

    NASA Astrophysics Data System (ADS)

    Pallud, C. E.; Matzen, S. L.; Olson, A.

    2015-12-01

    Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

  4. Soil compaction: Evaluation of stress transmission and resulting soil structure

    NASA Astrophysics Data System (ADS)

    Naveed, Muhammad; Schjønning, Per; Keller, Thomas; Lamande, Mathieu

    2016-04-01

    Accurate estimation of stress transmission and resultant deformation in soil profiles is a prerequisite for the development of predictive models and decision support tools for preventing soil compaction. Numerous studies have been carried out on the effects of soil compaction, whilst relatively few studies have focused on the cause (mode of stress transmission in the soil). We have coupled both cause and effects together in the present study by carrying out partially confined compression tests on (1) wet aggregates, (2) air dry aggregates, and (3) intact soils to quantify stress transmission and compaction-resulted soil structure at the same time. Stress transmission was quantified using both X-ray CT and Tactilus sensor mat, and soil-pore structure was quantified using X-ray CT. Our results imply that stress transmission through soil highly depends on the magnitude of applied load and aggregate strength. As soon as the applied load is lower than the aggregate strength, the mode of stress transmission is discrete as stresses were mainly transmitted through chain of aggregates. With increasing applied load soil aggregates start deforming that transformed heterogeneous soil into homogenous, as a result stress transmission mode was shifted from discrete towards more like a continuum. Continuum-like stress transmission mode was better simulated with Boussinesq (1885) model based on theory of elasticity compared to discrete. The soil-pore structure was greatly affected by increasing applied stresses. Total porosity was reduced 5-16% and macroporosity 50-85% at 620 kPa applied stress for the intact soils. Similarly, significant changes in the morphological indices of the macropore space were also observed with increasing applied stresses.

  5. Soil Functional Mapping: A Geospatial Framework for Scaling Soil Carbon Cycling

    NASA Astrophysics Data System (ADS)

    Lawrence, C. R.

    2017-12-01

    Climate change is dramatically altering biogeochemical cycles in most terrestrial ecosystems, particularly the cycles of water and carbon (C). These changes will affect myriad ecosystem processes of importance, including plant productivity, C exports to aquatic systems, and terrestrial C storage. Soil C storage represents a critical feedback to climate change as soils store more C than the atmosphere and aboveground plant biomass combined. While we know plant and soil C cycling are strongly coupled with soil moisture, substantial unknowns remain regarding how these relationships can be scaled up from soil profiles to ecosystems. This greatly limits our ability to build a process-based understanding of the controls on and consequences of climate change at regional scales. In an effort to address this limitation we: (1) describe an approach to classifying soils that is based on underlying differences in soil functional characteristics and (2) examine the utility of this approach as a scaling tool that honors the underlying soil processes. First, geospatial datasets are analyzed in the context of our current understanding of soil C and water cycling in order to predict soil functional units that can be mapped at the scale of ecosystems or watersheds. Next, the integrity of each soil functional unit is evaluated using available soil C data and mapping units are refined as needed. Finally, targeted sampling is conducted to further differentiate functional units or fill in any data gaps that are identified. Completion of this workflow provides new geospatial datasets that are based on specific soil functions, in this case the coupling of soil C and water cycling, and are well suited for integration with regional-scale soil models. Preliminary results from this effort highlight the advantages of a scaling approach that balances theory, measurement, and modeling.

  6. Field Identification of Andic Soil Properties for Soils of North-central Idaho

    Treesearch

    Brian Gardner

    2007-01-01

    Currently, laboratory measurements are definitive for identifying andic soil properties in both the USDA Soil Taxonomy (Soil Survey Staff 1999) and the World Reference Base for Soil Resources (FAO/ISRIC/ISSS 1998). Andic soil properties, as described in Soil Taxonomy, result mainly from the presence of significant amounts of allophone, imogolite, ferrihydrite or...

  7. Effects of soil management techniques on soil water erosion in apricot orchards.

    PubMed

    Keesstra, Saskia; Pereira, Paulo; Novara, Agata; Brevik, Eric C; Azorin-Molina, Cesar; Parras-Alcántara, Luis; Jordán, Antonio; Cerdà, Artemi

    2016-05-01

    Soil erosion is extreme in Mediterranean orchards due to management impact, high rainfall intensities, steep slopes and erodible parent material. Vall d'Albaida is a traditional fruit production area which, due to the Mediterranean climate and marly soils, produces sweet fruits. However, these highly productive soils are left bare under the prevailing land management and marly soils are vulnerable to soil water erosion when left bare. In this paper we study the impact of different agricultural land management strategies on soil properties (bulk density, soil organic matter, soil moisture), soil water erosion and runoff, by means of simulated rainfall experiments and soil analyses. Three representative land managements (tillage/herbicide/covered with vegetation) were selected, where 20 paired plots (60 plots) were established to determine soil losses and runoff. The simulated rainfall was carried out at 55mmh(-1) in the summer of 2013 (<8% soil moisture) for one hour on 0.25m(2) circular plots. The results showed that vegetation cover, soil moisture and organic matter were significantly higher in covered plots than in tilled and herbicide treated plots. However, runoff coefficient, total runoff, sediment yield and soil erosion were significantly higher in herbicide treated plots compared to the others. Runoff sediment concentration was significantly higher in tilled plots. The lowest values were identified in covered plots. Overall, tillage, but especially herbicide treatment, decreased vegetation cover, soil moisture, soil organic matter, and increased bulk density, runoff coefficient, total runoff, sediment yield and soil erosion. Soil erosion was extremely high in herbicide plots with 0.91Mgha(-1)h(-1) of soil lost; in the tilled fields erosion rates were lower with 0.51Mgha(-1)h(-1). Covered soil showed an erosion rate of 0.02Mgha(-1)h(-1). These results showed that agricultural management influenced water and sediment dynamics and that tillage and herbicide

  8. Dynamics of soil organic carbon and microbial activity in treated wastewater irrigated agricultural soils along soil profiles

    NASA Astrophysics Data System (ADS)

    Jüschke, Elisabeth; Marschner, Bernd; Chen, Yona; Tarchitzky, Jorge

    2010-05-01

    Treated wastewater (TWW) is an important source for irrigation water in arid and semiarid regions and already serves as an important water source in Jordan, the Palestinian Territories and Israel. Reclaimed water still contains organic matter (OM) and various compounds that may effect microbial activity and soil quality (Feigin et al. 1991). Natural soil organic carbon (SOC) may be altered by interactions between these compounds and the soil microorganisms. This study evaluates the effects of TWW irrigation on the quality, dynamics and microbial transformations of natural SOC. Priming effects (PE) and SOC mineralization were determined to estimate the influence of TWW irrigation on SOC along soil profiles of agricultural soils in Israel and the Westbank. The used soil material derived from three different sampling sites allocated in Israel and The Palestinian Authority. Soil samples were taken always from TWW irrigated sites and control fields from 6 different depths (0-10, 10-20, 20-30, 30-50, 50-70, 70-100 cm). Soil carbon content and microbiological parameters (microbial biomass, microbial activities and enzyme activities) were investigated. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. The fact that PE are triggered continuously due to TWW irrigation may result in a decrease of SOC over long term irrigation. Already now this could be

  9. Degradation kinetics of ptaquiloside in soil and soil solution.

    PubMed

    Ovesen, Rikke Gleerup; Rasmussen, Lars Holm; Hansen, Hans Christian Bruun

    2008-02-01

    Ptaquiloside (PTA) is a carcinogenic norsesquiterpene glycoside produced in bracken (Pteridium aquilinum (L.) Kuhn), a widespread, aggressive weed. Transfer of PTA to soil and soil solution eventually may contaminate groundwater and surface water. Degradation rates of PTA were quantified in soil and soil solutions in sandy and clayey soils subjected to high natural PTA loads from bracken stands. Degradation kinetics in moist soil could be fitted with the sum of a fast and a slow first-order reaction; the fast reaction contributed 20 to 50% of the total degradation of PTA. The fast reaction was similar in all horizons, with the rate constant k(1F) ranging between 0.23 and 1.5/h. The slow degradation, with the rate constant k(1S) ranging between 0.00067 and 0.029/ h, was more than twice as fast in topsoils compared to subsoils, which is attributable to higher microbial activity in topsoils. Experiments with sterile controls confirmed that nonmicrobial degradation processes constituted more than 90% of the fast degradation and 50% of the slow degradation. The lower nonmicrobial degradation rate observed in the clayey compared with the sandy soil is attributed to a stabilizing effect of PTA by clay silicates. Ptaquiloside appeared to be stable in all soil solutions, in which no degradation was observed within a period of 28 d, in strong contrast to previous studies of hydrolysis rates in artificial aqueous electrolytes. The present study predicts that the risk of PTA leaching is controlled mainly by the residence time of pore water in soil, soil microbial activity, and content of organic matter and clay silicates.

  10. Biotic and Abiotic Soil Properties Influence Survival of Listeria monocytogenes in Soil

    PubMed Central

    Locatelli, Aude; Spor, Aymé; Jolivet, Claudy; Piveteau, Pascal; Hartmann, Alain

    2013-01-01

    Listeria monocytogenes is a food-borne pathogen responsible for the potentially fatal disease listeriosis and terrestrial ecosystems have been hypothesized to be its natural reservoir. Therefore, identifying the key edaphic factors that influence its survival in soil is critical. We measured the survival of L. monocytogenes in a set of 100 soil samples belonging to the French Soil Quality Monitoring Network. This soil collection is meant to be representative of the pedology and land use of the whole French territory. The population of L. monocytogenes in inoculated microcosms was enumerated by plate count after 7, 14 and 84 days of incubation. Analysis of survival profiles showed that L. monocytogenes was able to survive up to 84 days in 71% of the soils tested, in the other soils (29%) only a short-term survival (up to 7 to 14 days) was observed. Using variance partitioning techniques, we showed that about 65% of the short-term survival ratio of L. monocytogenes in soils was explained by the soil chemical properties, amongst which the basic cation saturation ratio seems to be the main driver. On the other hand, while explaining a lower amount of survival ratio variance (11%), soil texture and especially clay content was the main driver of long-term survival of L. monocytogenes in soils. In order to assess the effect of the endogenous soils microbiota on L. monocytogenes survival, sterilized versus non-sterilized soils microcosms were compared in a subset of 9 soils. We found that the endogenous soil microbiota could limit L. monocytogenes survival especially when soil pH was greater than 7, whereas in acidic soils, survival ratios in sterilized and unsterilized microcosms were not statistically different. These results point out the critical role played by both the endogenous microbiota and the soil physic-chemical properties in determining the survival of L. monocytogenes in soils. PMID:24116083

  11. Distinct impacts of reductive soil disinfestation and chemical soil disinfestation on soil fungal communities and memberships.

    PubMed

    Zhao, Jun; Zhou, Xing; Jiang, Anqi; Fan, Juanzi; Lan, Tao; Zhang, Jinbo; Cai, Zucong

    2018-06-21

    Soil disinfestation is an important agricultural practice to conquer soil-borne diseases and thereby ensure crop productivity. Reductive soil disinfestation (RSD) had been developed as an environmentally friendly alternative to chemical soil disinfestation (CSD). However, the differences between CSD and RSD on soil-borne pathogen suppression and fungal community structure remain poorly understood. In this work, five treatments, i.e., untreated soil (CK), CSD with 0.5 t ha -1 dazomet (DZ), RSD with 10 t ha -1 ethanol (ET), 15 t ha -1 sugarcane bagasse (SB), and 15 t ha -1 bean dregs (BD), were performed to investigate their influences on disinfestation efficiency, fungal abundance, diversity, and community structure via quantitative PCR and high-throughput sequencing. RSD-related treatments, especially the BD treatment, effectively alleviated soil acidification and salinization. The fungal abundance and microbial activity considerably increased in the BD treatment and significantly declined in the DZ treatment as compared to the CK treatment. Moreover, both CSD and RSD-related treatments significantly inhibited the population of Fusarium oxysporum and the relative abundance of genus Fusarium. Fungal community structure was notably altered by CSD and RSD practices. Furthermore, both CSD and RSD harbored a distinct unique microbiome, with the DZ treatment dominated by the genus Mortierella and BD treatment predominated by the genera Zopfiella, Chaetomium, and Penicillium. Taken together, these results indicate that the BD treatment could considerably alleviate the soil deterioration, improve soil microbial activity, and reassemble a non-pathogen unique microbiome that have more disease-suppressive agents and thus might be a promising disinfestation practice to control soil-borne disease in monoculture system.

  12. What Is Soil? Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the first of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil management. Upon completing the two day lesson, the student will be able to define "soil", list the soil forming agencies, define and use soil terminology, and discuss soil formation and…

  13. [Effect of trampling disturbance on soil infiltration of biological soil crusts].

    PubMed

    Shi, Ya Fang; Zhao, Yun Ge; Li, Chen Hui; Wang, Shan Shan; Yang, Qiao Yun; Xie, Shen Qi

    2017-10-01

    The effect of trampling disturbance on soil infiltration of biological soil crusts was investigated by using simulated rainfall. The results showed that the trampling disturbance significantly increased soil surface roughness. The increasing extent depended on the disturbance intensity. Soil surface roughness values at 50% disturbance increased by 91% compared with the undisturbed treatment. The runoff was delayed by trampling disturbance. A linear increase in the time of runoff yield was observed along with the increasing disturbance intensity within 20%-50%. The time of runoff yield at 50% disturbance increased by 169.7% compared with the undisturbed treatment. Trampling disturbance increased soil infiltration and consequently decreased the runoff coefficient. The cumulative infiltration amount at 50% disturbance increased by 12.6% compared with the undisturbed treatment. Soil infiltration significant decreased when biocrusts were removed. The cumulative infiltration of the treatment of biocrusts removal decreased by 30.2% compared with the undisturbed treatment. Trampling disturbance did not significantly increase the soil loss when the distur bance intensity was lower than 50%, while the biocrusts removal resulted in 10 times higher in soil erosion modulus. The trampling disturbance of lower than 50% on biocrusts might improve soil infiltration and reduce the risk of runoff, thus might improve the soil moisture without obviously increa sing the soil loss.

  14. Approximating Phosphorus Leaching from Agricultural Organic Soils by Soil Testing.

    PubMed

    Zheng, Z M; Zhang, T Q; Kessel, C; Tan, C S; O'Halloran, I P; Wang, Y T; Speranzini, D; Van Eerd, L L

    2015-11-01

    Phosphorus applied to soils in excess of crop requirement could create situations favorable to P enrichment in subsurface flow that contributes to eutrophication of surface water. This pathway of P loss can be more severe in muck (i.e., organic) soils where agricultural production is intensive. This study evaluated the suitability of various environmental and agronomic soil P tests initially designed for mineral soils to predict dissolved reactive P (DRP) in subsurface flow from organic soils. Intact soil columns were collected from 44 muck soils in Ontario to provide a wide range of soil test P levels. A lysimeter leaching study was conducted by evenly adding water in an amount equivalent to 5 mm of rainfall. The leachate DRP concentration was linearly related to soil water-extractable P and CaCl-extractable P with values of 0.90 and 0.93, respectively, and to Bray-1 P and FeO-impregnated filter paper extractable P in a split-line model with a change point. Mehlich-3 P and Olsen P, a method recommended for agronomic P calibration in Ontario, were not related to leachate DRP concentration. All P sorption index (PSI) based degree of P saturation (DPS) values were closely related to leachate DRP in split-line models, with the DPS indices expressed as Bray-1 P/PSI and FeO-P/PSI having the highest correlation with leachate DRP concentration. Because it is desirable from practical and economic standpoints that the environmental risk assessment shares the same soil test with agronomic P calibration, the two PSI-based DPS indices as presented can be considered as environmental risk indicators of DRP subsurface loss from organic soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. The Glinka Memorial Soil Monolith Collection: a treasure of Soil Science

    NASA Astrophysics Data System (ADS)

    Muggler, C. C.; Spaargaren, O.; Hartemink, A. E.

    2012-04-01

    The first World Congress of Soil Science, held in 1927 in Washington DC, USA, had as one of its highlights the exposition of soils from all over the world. The Russian delegation had planned the presentation of 50 soil monoliths. The soil profiles were collected under the supervision of Konstantin D. Glinka, then director of the Leningrad Agricultural Institute. The soil profiles included a geographical sequence form St Petersburg to the Caucasus and soils from Georgia, Azerbaijan, Kazakhstan, the Amu Darya region and the Siberian Far East. Due to shipping problems they did not arrive on time for the congress, and ended up in an USDA storage facility, where they remained untouched in their original wooden boxes. At first congress Glinka gave a lecture on Dokuchaev's ideas and the Russian developments on soil science, and joined the transcontinental field trip of 30 days that followed the congress. At that congress, Glinka was elected president of the International Soil Science Society, and was in charge to organize the next congress in Russia. However, he passed away a few months after the congress. In the 1970s, after a consultation with Wim Sombroek, then director of the International Soil Museum (ISM) in the Netherlands, the collection was donated to ISRIC by the US Soil Conservation Service. The soil profiles were shipped over in 1980 to become part of the collection of the Museum. The collection was named as "Glinka Memorial Collection" in agreement with the Dokuchaev Soil Institute, Moscow and the U.S. Soil Conservation Service, Washington. The monoliths were treated with a sugar solution by the Russians before shipment to the USA, this way keeping a good preservation quality. They were aimed for a single exhibition and for that they were poorly documented and lacked additional samples. In the early 1990s a project for revisit the sites was set up and six sites around St Petersburg were sampled for a comparative study of the soils within a time span of 70

  16. Long-term measurements of aerosols and carbon monoxide at the ZOTTO tall tower to characterize polluted and pristine air in the Siberian Taiga

    NASA Astrophysics Data System (ADS)

    Chi, X.; Winderlich, J.; Mayer, J.-C.; Panov, A. V.; Heimann, M.; Birmili, W.; Heintzenberg, J.; Cheng, Y.; Andreae, M. O.

    2013-07-01

    Siberia is one of few background regions in the Northern Hemisphere where the atmosphere may sometimes approach pristine conditions. We present the time series of aerosol and carbon monoxide (CO) measurements between September~2006 and December 2010 at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 90° E). We investigate the seasonal, weekly and diurnal variations of aerosol properties (including absorption and scattering coefficients and derived parameters, like equivalent black carbon (BCe), Ångström exponent, single scattering albedo, and backscattering ratio) and the CO mixing ratios. Criteria were established to distinguish polluted and near-pristine air masses and characterize them separately. Depending on the season, 15-47% of the sampling time at ZOTTO was representative of a clean atmosphere. The summer pristine data indicates that primary biogenic and/or secondary organic aerosol formation are quite strong particle sources in the Siberian Taiga. The summer seasons 2007-2008 are dominated by an Aitken mode of 80 nm size, whereas the summer 2009 with prevailing easterly winds produced aerosols in the accumulation mode around 200 nm size. We found these differences mainly related to air temperature, in parallel with production rates of biogenic volatile organic compounds (VOC). In winter, the footprint and aerosol size distribution (with a peak at 160 nm) of the clean background air are characteristic for aged aerosols from anthropogenic sources at great distances from ZOTTO and diluted biofuel burning emissions from heating. The wintertime polluted air originates from the large cities to the south and southwest of the site; these aerosols have a dominant mode around 100 nm, and the Δ BCe/Δ CO ratio of 7-11 ng m-3 ppb-1 suggests dominant contributions from coal and biofuel burning for heating. During summer, anthropogenic emissions are the dominant contributor to the pollution aerosols at ZOTTO, while only 12% of the polluted

  17. Soil properties controlling Zn speciation and fractionation in contaminated soils

    NASA Astrophysics Data System (ADS)

    Jacquat, Olivier; Voegelin, Andreas; Kretzschmar, Ruben

    2009-09-01

    We determined the speciation of Zn in 49 field soils differing widely in pH (4.1-7.7) and total Zn content (251-30,090 mg/kg) by using extended X-ray absorption fine structure (EXAFS) spectroscopy. All soils had been contaminated since several decades by inputs of aqueous Zn with runoff-water from galvanized power line towers. Pedogenic Zn species identified by EXAFS spectroscopy included Zn in hydroxy-interlayered minerals (Zn-HIM), Zn-rich phyllosilicates, Zn-layered double hydroxide (Zn-LDH), hydrozincite, and octahedrally and tetrahedrally coordinated sorbed or complexed Zn. Zn-HIM was only observed in (mostly acidic) soils containing less than 2000 mg/kg of Zn, reflecting the high affinity but limited sorption capacity of HIM. Zn-bearing precipitates, such as Zn-LDH and Zn-rich trioctahedral phyllosilicates, became more dominant with increasing pH and increasing total Zn content relative to available adsorption sites. Zn-LDH was the most abundant Zn-precipitate and was detected in soils with pH > 5.2. Zn-rich phyllosilicates were detected even at lower soil pH, but were generally less abundant than Zn-LDH. Hydrozincite was only identified in two calcareous soils with extremely high Zn contents. In addition to Zn-LDH, large amounts of Zn in highly contaminated soils were mainly accumulated as sorbed/complexed Zn in tetrahedral coordination. Soils grouped according to their Zn speciation inferred from EXAFS spectroscopy mainly differed with respect to soil pH and total Zn content. Clear differences were observed with respect to Zn fractionation by sequential extraction: From Zn-HIM containing soils, most of the total Zn was recovered in the exchangeable and the most recalcitrant fractions. In contrast, from soils containing the highest percentage of Zn-precipitates, Zn was mainly extracted in intermediate extraction steps. The results of this study demonstrate that soil pH and Zn contamination level relative to available adsorption sites are the most important

  18. SoilNet - A Zigbee based soil moisture sensor network

    NASA Astrophysics Data System (ADS)

    Bogena, H. R.; Weuthen, A.; Rosenbaum, U.; Huisman, J. A.; Vereecken, H.

    2007-12-01

    Soil moisture plays a key role in partitioning water and energy fluxes, in providing moisture to the atmosphere for precipitation, and controlling the pattern of groundwater recharge. Large-scale soil moisture variability is driven by variation of precipitation and radiation in space and time. At local scales, land cover, soil conditions, and topography act to redistribute soil moisture. Despite the importance of soil moisture, it is not yet measured in an operational way, e.g. for a better prediction of hydrological and surface energy fluxes (e.g. runoff, latent heat) at larger scales and in the framework of the development of early warning systems (e.g. flood forecasting) and the management of irrigation systems. The SoilNet project aims to develop a sensor network for the near real-time monitoring of soil moisture changes at high spatial and temporal resolution on the basis of the new low-cost ZigBee radio network that operates on top of the IEEE 802.15.4 standard. The sensor network consists of soil moisture sensors attached to end devices by cables, router devices and a coordinator device. The end devices are buried in the soil and linked wirelessly with nearby aboveground router devices. This ZigBee wireless sensor network design considers channel errors, delays, packet losses, and power and topology constraints. In order to conserve battery power, a reactive routing protocol is used that determines a new route only when it is required. The sensor network is also able to react to external influences, e.g. such as rainfall occurrences. The SoilNet communicator, routing and end devices have been developed by the Forschungszentrum Juelich and will be marketed through external companies. We will present first results of experiments to verify network stability and the accuracy of the soil moisture sensors. Simultaneously, we have developed a data management and visualisation system. We tested the wireless network on a 100 by 100 meter forest plot equipped with 25

  19. [Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].

    PubMed

    Chen, Xiang-Bi; Wang, Ai-Hua; Hu, Le-Ning; Huang, Yuan; Li, Yang; He, Xun-Yang; Su, Yi-Rong

    2014-03-01

    Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction.

  20. Synthesis of soil-hydraulic properties and infiltration timescales in wildfire-affected soils

    USGS Publications Warehouse

    Ebel, Brian A.; Moody, John A.

    2017-01-01

    We collected soil-hydraulic property data from the literature for wildfire-affected soils, ash, and unburned soils. These data were used to calculate metrics and timescales of hydrologic response related to infiltration and surface runoff generation. Sorptivity (S) and wetting front potential (Ψf) were significantly different (lower) in burned soils compared with unburned soils, whereas field-saturated hydraulic conductivity (Kfs) was not significantly different. The magnitude and duration of the influence of capillarity during infiltration was greatly reduced in burned soils, causing faster ponding times in response to rainfall. Ash had large values of S and Kfs but moderate values of Ψf, compared with unburned and burned soils, indicating ash has long ponding times in response to rainfall. The ratio of S2/Kfs was nearly constant (~100 mm) for unburned soils but more variable in burned soils, suggesting that unburned soils have a balance between gravity and capillarity contributions to infiltration that may depend on soil organic matter, whereas in burned soils the gravity contribution to infiltration is greater. Changes in S and Kfs in burned soils act synergistically to reduce infiltration and accelerate and amplify surface runoff generation. Synthesis of these findings identifies three key areas for future research. First, short timescales of capillary influences on infiltration indicate the need for better measurements of infiltration at times less than 1 min to accurately characterize S in burned soils. Second, using parameter values, such as Ψf, from unburned areas could produce substantial errors in hydrologic modeling when used without adjustment for wildfire effects, causing parameter compensation and resulting underestimation of Kfs. Third, more thorough measurement campaigns that capture soil-structural changes, organic matter impacts, quantitative water repellency trends, and soil-water content along with soil-hydraulic properties could drive the

  1. Remediation of soils combining soil vapor extraction and bioremediation: benzene.

    PubMed

    Soares, António Alves; Albergaria, José Tomás; Domingues, Valentina Fernandes; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

    2010-08-01

    This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase. (c) 2010 Elsevier Ltd. All rights reserved.

  2. Biochar has no effect on soil respiration across Chinese agricultural soils.

    PubMed

    Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

    2016-06-01

    Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils. Copyright © 2016. Published by Elsevier B.V.

  3. Soil solid-phase controls lead activity in soil solution.

    PubMed

    Badawy, S H; Helal, M I D; Chaudri, A M; Lawlor, K; McGrath, S P

    2002-01-01

    Lead pollution of the environment is synonymous with civilization. It has no known biological function, and is naturally present in soil, but its presence in food crops is deemed undesirable. The concern regarding Pb is mostly due to chronic human and animal health effects, rather then phytotoxicity. However, not much is known about the chemistry and speciation of Pb in soils. We determined the activity of Pb2+, in near neutral and alkaline soils, representative of alluvial, desertic and calcareous soils of Egypt, using the competitive chelation method. Lead activity ranged from 10(-6.73) to 10(-4.83) M, and was negatively correlated with soil and soil solution pH (R2 = -0.92, P < 0.01 and R2 = -0.89, P < 0.01, respectively). It could be predicted in soil solution from the equation: log(Pb2+) = 9.9 - 2pH. A solubility diagram for the various Pb minerals found in soil was constructed using published thermodynamic data obtained from the literature, and our measured Pb2+ activities compared with this information. The measured Pb2+ activities were undersaturated with regard to the solubility of PbSiO3 in equilibrium with SiO2 (soil). However, they were supersaturated with regard to the solubilities of the Pb carbonate minerals PbCO3 (cerussite) and Pb3(CO3)2(OH)2 in equilibrium with atmospheric CO2 and hydroxide Pb(OH)2. They were also supersaturated with regard to the solubilities of the Pb phosphate minerals Pb3(PO4)2, Pb5(PO4)3OH, and Pb4O(PO4)2 in equilibrium with tricalcium phosphate and CaCO3. The activity of Pb2+ was not regulated by any mineral of known solubility in our soils, but possibly by a mixture of Pb carbonate and phosphate minerals.

  4. Spatial variability of soil hydraulics and remotely sensed soil parameters

    NASA Technical Reports Server (NTRS)

    Lascano, R. J.; Van Bavel, C. H. M.

    1982-01-01

    The development of methods to correctly interpret remotely sensed information about soil moisture and soil temperature requires an understanding of water and energy flow in soil, because the signals originate from the surface, or from a shallow surface layer, but reflect processes in the entire profile. One formidable difficulty in this application of soil physics is the spatial heterogeneity of natural soils. Earlier work has suggested that the heterogeneity of soil hydraulic properties may be described by the frequency distribution of a single scale factor. The sensitivity of hydraulic and energetic processes to the variation of this scale factor is explored with a suitable numerical model. It is believed that such an analysis can help in deciding how accurately and extensively basic physical properties of field soils need to be known in order to interpret thermal or radar waveband signals. It appears that the saturated hydraulic conductivity needs to be known only to its order of magnitude, and that the required accuracy of the soil water retention function is about 0.02 volume fraction. Furthermore, the results may be helpful in deciding how the total scene or view field, as perceived through a sensor, is composed from the actual mosaic of transient soil properties, such as surface temperature or surface soil moisture. However, the latter proposition presupposes a random distribution of permanent properties, a condition that may not be met in many instances, and no solution of the problem is apparent.

  5. Soil Water Retention as Indicator for Soil Physical Quality - Examples from Two SoilTrEC European Critical Zone Observatories

    NASA Astrophysics Data System (ADS)

    Rousseva, Svetla; Kercheva, Milena; Shishkov, Toma; Dimitrov, Emil; Nenov, Martin; Lair, Georg J.; Moraetis, Daniel

    2014-05-01

    Soil water retention is of primary importance for majority of soil functions. The characteristics derived from Soil Water Retention Curve (SWRC) are directly related to soil structure and soil water regime and can be used as indicators for soil physical quality. The aim of this study is to present some parameters and relationships based on the SWRC data from the soil profiles characterising the European SoilTrEC Critical Zone Observatories Fuchsenbigl and Koiliaris. The studied soils are representative for highly productive soils managed as arable land in the frame of soil formation chronosequence at "Marchfeld" (Fuchsenbigl CZO), Austria and heavily impacted soils during centuries through intensive grazing and farming, under severe risk of desertification in context of climatic and lithological gradient at Koiliaris, Crete, Greece. Soil water retention at pF ≤ 2.52 was determined using the undisturbed soil cores (100 cm3 and 50 cm3) by a suction plate method. Water retention at pF = 4.2 was determined by a membrane press method and at pF ≥ 5.6 - by adsorption of water vapour at controlled relative humidity, both using ground soil samples. The soil physical quality parameter (S-parameter) was defined as the slope of the water retention curve at its inflection point (Dexter, 2006), determined with the obtained parameters of van Genuhten (1980) water retention equation. The S-parameter values were categorised to assess soil physical quality as follows: S < 0.020 very poor, 0.020 ≤ S < 0.035 poor, 0.035 ≤ S < 0.050 good, S ≥ 0.050 very good (Dexter, 2004). The results showed that most of the studied topsoil horizons have good physical quality according to both the S-parameter and the Plant-Available Water content (PAW), with the exception of the soils from croplands at CZO Fuxenbigl (F4, F5) which are with poor soil structure. The link between the S-parameter and the indicator of soil structure stability (water stable soil aggregates with size 1-3 mm) is not

  6. Using USDA's National Cooperative Soil Survey Soil Characterization Data to detect soil change: A cautionary tale

    USDA-ARS?s Scientific Manuscript database

    Recently, the USDA-NRCS National Cooperative Soil Survey Soil Characterization Database (NSCD) was reported to provide evidence that total nitrogen (TN) stocks of agricultural soils have increased across the Mississippi basin since 1985. Unfortunately, due to omission of metadata from the NSCD, hist...

  7. The UK Soil Observatory (UKSO) and mySoil app: crowdsourcing and disseminating soil information.

    NASA Astrophysics Data System (ADS)

    Robinson, David; Bell, Patrick; Emmett, Bridget; Panagos, Panos; Lawley, Russell; Shelley, Wayne

    2017-04-01

    Digital technologies in terms of web based data portals and mobiles apps offer a new way to provide both information to the public, and to engage the public in becoming involved in contributing to the effort of collecting data through crowdsourcing. We are part of the Landpotential.org consortium which is a global partnership committed to developing and supporting the adoption of freely available technology and tools for sustainable land use management, monitoring, and connecting people across the globe. The mySoil app was launched in 2012 and is an example of a free mobile application downloadable from iTunes and Google Play. It serves as a gateway tool to raise interest in, and awareness of, soils. It currently has over 50,000 dedicated users and has crowd sourced more than 4000 data records. Recent developments have expanded the coverage of mySoil from the United Kingdom to Europe, introduced a new user interface and provided language capability, while the UKSO displays the crowd-sourced records from across the globe. We are now trying to identify which industry, education and citizen sectors are using these platforms and how they can be improved. Please help us by providing feedback or taking the survey on the UKSO website. www.UKSO.org The UKSO is a collaboration between major UK soil-data holders to provide maps, spatial data and real-time temporal data from observing platforms such as the UK soil moisture network. Both UKSO and mySoil have crowdsourcing capability and are slowly building global citizen science maps of soil properties such as pH and texture. Whilst these data can't replace professional monitoring data, the information they provide both stimulates public interest and can act as 'soft data' that can help support the interpretation of monitoring data, or guide future monitoring, identifying areas that don't correspond with current analysis. In addition, soft data can be used to map soils with machine learning approaches, such as SoilGrids.

  8. An evaluation of different soil washing solutions for remediating arsenic-contaminated soils.

    PubMed

    Wang, Yiwen; Ma, Fujun; Zhang, Qian; Peng, Changsheng; Wu, Bin; Li, Fasheng; Gu, Qingbao

    2017-04-01

    Soil washing is a promising way to remediate arsenic-contaminated soils. Most research has mostly focused on seeking efficient extractants for removing arsenic, but not concerned with any changes in soil properties when using this technique. In this study, the removal of arsenic from a heavily contaminated soil employing different washing solutions including H 3 PO 4 , NaOH and dithionite in EDTA was conducted. Subsequently, the changes in soil physicochemical properties and phytotoxicity of each washing technique were evaluated. After washing with 2 M H 3 PO 4 , 2 M NaOH or 0.1 M dithionite in 0.1 M EDTA, the soil samples' arsenic content met the clean-up levels stipulated in China's environmental regulations. H 3 PO 4 washing decreased soil pH, Ca, Mg, Al, Fe, and Mn concentrations but increased TN and TP contents. NaOH washing increased soil pH but decreased soil TOC, TN and TP contents. Dithionite in EDTA washing reduced soil TOC, Ca, Mg, Al, Fe, Mn and TP contents. A drastic color change was observed when the soil sample was washed with H 3 PO 4 or 0.1 M dithionite in 0.1 M EDTA. After adjusting the soil pH to neutral, wheat planted in the soil sample washed by NaOH evidenced the best growth of all three treated soil samples. These results will help with selecting the best washing solution when remediating arsenic-contaminated soils in future engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Global soil-climate-biome diagram: linking soil properties to climate and biota

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Yang, Y.; Fang, J.

    2017-12-01

    As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

  10. Effects of myclobutanil on soil microbial biomass, respiration, and soil nitrogen transformations.

    PubMed

    Ju, Chao; Xu, Jun; Wu, Xiaohu; Dong, Fengshou; Liu, Xingang; Zheng, Yongquan

    2016-01-01

    A 3-month-long experiment was conducted to ascertain the effects of different concentrations of myclobutanil (0.4 mg kg(-1) soil [T1]; 1.2 mg kg(-1) soil [T3]; and 4 mg kg(-1) soil [T10]) on soil microbial biomass, respiration, and soil nitrogen transformations using two typical agricultural soils (Henan fluvo-aquic soil and Shanxi cinnamon soil). Soil was sampled after 7, 15, 30, 60, and 90 days of incubation to determine myclobutanil concentration and microbial parameters: soil basal respiration (RB), microbial biomass carbon (MBC) and nitrogen (MBN), NO(-)3-N and NH(+)4-N concentrations, and gene abundance of total bacteria, N2-fixing bacteria, fungi, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). The half-lives of the different doses of myclobutanil varied from 20.3 to 69.3 d in the Henan soil and from 99 to 138.6 d in the Shanxi soil. In the Henan soil, the three treatments caused different degrees of short-term inhibition of RB and MBC, NH(+)4-N, and gene abundance of total bacteria, fungi, N2-fixing bacteria, AOA, and AOB, with the exception of a brief increase in NO(-)3-N content during the T10 treatment. The MBN (immobilized nitrogen) was not affected. In the Shanxi soil, MBC, the populations of total bacteria, fungi, and N2-fixing bacteria, and NH(+)4-N concentration were not significantly affected by myclobutanil. The RB and MBN were decreased transitorily in the T10 treatment. The NO(-)3-N concentrations and the abundance of both AOA and AOB were erratically stimulated by myclobutanil. Regardless of whether stimulation or suppression occurred, the effects of myclobutanil on the two soil types were short term. In summary, myclobutanil had no long-term negative effects on the soil microbial biomass, respiration, and soil nitrogen transformations in the two types of soil, even at 10-fold the recommended dosage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  12. Estimating Soil Cation Exchange Capacity from Soil Physical and Chemical Properties

    NASA Astrophysics Data System (ADS)

    Bateni, S. M.; Emamgholizadeh, S.; Shahsavani, D.

    2014-12-01

    The soil Cation Exchange Capacity (CEC) is an important soil characteristic that has many applications in soil science and environmental studies. For example, CEC influences soil fertility by controlling the exchange of ions in the soil. Measurement of CEC is costly and difficult. Consequently, several studies attempted to obtain CEC from readily measurable soil physical and chemical properties such as soil pH, organic matter, soil texture, bulk density, and particle size distribution. These studies have often used multiple regression or artificial neural network models. Regression-based models cannot capture the intricate relationship between CEC and soil physical and chemical attributes and provide inaccurate CEC estimates. Although neural network models perform better than regression methods, they act like a black-box and cannot generate an explicit expression for retrieval of CEC from soil properties. In a departure with regression and neural network models, this study uses Genetic Expression Programming (GEP) and Multivariate Adaptive Regression Splines (MARS) to estimate CEC from easily measurable soil variables such as clay, pH, and OM. CEC estimates from GEP and MARS are compared with measurements at two field sites in Iran. Results show that GEP and MARS can estimate CEC accurately. Also, the MARS model performs slightly better than GEP. Finally, a sensitivity test indicates that organic matter and pH have respectively the least and the most significant impact on CEC.

  13. The World Soil Museum: education and advocacy on soils of the world

    NASA Astrophysics Data System (ADS)

    Mantel, Stephan; Land, Hiske

    2013-04-01

    The World Soil Museum (WSM) in Wageningen, is part of ISRIC World Soil Information and was founded in 1966 on request of the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the International Soil Science Society. The World Soil Museum has a collection of over 1100 soil profiles from more than 70 countries. This soil profiles are vertical sections and show the composition, layering and structure of the soil. The collection is unique in the world and includes a significant number of soil profiles from the Netherlands. The Dutch soil collection is important for serving broader visitor groups, as some visitors, such as secondary school classes, are specifically interested in the Dutch landscape and soils. Broadly speaking, the World Soil Museum has five functions: (i) education and courses, (ii) research, (iii) information and edutainment, (iv) social function, and (v) a real museum function (Art). The World Soil Museum (World Soil Museum) is well known in national and international circles soil and the English name has almost 1,000 references on the Internet. The World Soil Museum is visited by about 1000 people a year, mainly university and college students from Western Europe. Other visitor groups that have found their way to the museum are students from disciplines broader then soil science, such as geography and rural development. Secondary school classes visit the museum for geography classes. The uniqueness and the value of the collection of soil profiles (soil monoliths) and associated collections, such as soil samples, hand pieces, thin sections, slides, is emphasized by the fact ISRIC is the only World Data Centre for Soils (WDC-Soils) within the World Data System of the International Council of Science (ICSU). The collection provides an insight in and overview of the diversity of soils in the world, their properties and their limitations and possibilities for use. A new building is under construction for the WSM, which is

  14. Soil in the City: Sustainably Improving Urban Soils.

    PubMed

    Kumar, Kuldip; Hundal, Lakhwinder S

    2016-01-01

    Large tracts of abandoned urban land, resulting from the deindustrialization of metropolitan areas, are generating a renewed interest among city planners and community organizations envisioning the productive use of this land not only to produce fresh food but to effectively manage stormwater and mitigate the impact of urban heat islands. Healthy and productive soils are paramount to meet these objectives. However, these urban lands are often severely degraded due to anthropogenic activities and are generally contaminated with priority pollutants, especially heavy metals and polycyclic aromatic hydrocarbons. Characterizing these degraded and contaminated soils and making them productive again to restore the required ecosystem services was the theme of the "Soil in the City- 2014" conference organized by W-2170 Committee (USDA's Sponsored Multi-State Research Project: Soil-Based Use of Residuals, Wastewater, & Reclaimed Water). This special section of comprises 12 targeted papers authored by conference participants to make available much needed information about the characteristics of urban soils. Innovative ways to mitigate the risks from pollutants and to improve the soil quality using local resources are discussed. Such practices include the use of composts and biosolids to grow healthy foods, reclaim brownfields, manage stormwater, and improve the overall ecosystem functioning of urban soils. These papers provide a needed resource for educating policymakers, practitioners, and the general public about using locally available resources to restore fertility, productivity, and ecosystem functioning of degraded urban land to revitalize metropolitan areas for improving the overall quality of life for a large segment of a rapidly growing urban population. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Modeling the Dynamics of Soil Structure and Water in Agricultural Soil

    NASA Astrophysics Data System (ADS)

    Weller, U.; Lang, B.; Rabot, E.; Stössel, B.; Urbanski, L.; Vogel, H. J.; Wiesmeier, M.; Wollschlaeger, U.

    2017-12-01

    The impact of agricultural management on soil functions is manifold and severe. It has both positive and adverse influence. Our goal is to develop model tools quantifying the agricultural impact on soil functions based on a mechanistic understanding of soil processes to support farmers and decision makers. The modeling approach is based on defining relevant soil components, i.e. soil matrix, macropores, organisms, roots and organic matter. They interact and form the soil's macroscopic properties and functions including water and gas dynamics, and biochemical cycles. Based on existing literature information we derive functional interaction processes and combine them in a network of dynamic soil components. In agricultural soils, a major issue is linked to changes in soil structure and their influence on water dynamics. Compaction processes are well studied in literature, but for the resilience due to root growth and activity of soil organisms the information is scarcer. We implement structural dynamics into soil water and gas simulations using a lumped model that is both coarse enough to allow extensive model runs while still preserving some important, yet rarely modeled phenomenons like preferential flow, hysteretic and dynamic behavior. For simulating water dynamics, at each depth, the model assumes water at different binding energies depending on soil structure, i.e. the pore size distribution. Non-equilibrium is postulated, meaning that free water may occur even if the soil is not fully saturated. All energy levels are interconnected allowing water to move, both within a spatial node, and between neighboring nodes (adding gravity). Structure dynamics alters the capacity of this water compartments, and the conductance of its connections. Connections are switched on and off depending on whether their sources contain water or their targets have free capacity. This leads to piecewise linear system behavior that allows fast calculation for extended time steps. Based

  16. Gap assessment in current soil monitoring networks across Europe for measuring soil functions

    NASA Astrophysics Data System (ADS)

    van Leeuwen, J. P.; Saby, N. P. A.; Jones, A.; Louwagie, G.; Micheli, E.; Rutgers, M.; Schulte, R. P. O.; Spiegel, H.; Toth, G.; Creamer, R. E.

    2017-12-01

    Soil is the most important natural resource for life on Earth after water. Given its fundamental role in sustaining the human population, both the availability and quality of soil must be managed sustainably and protected. To ensure sustainable management we need to understand the intrinsic functional capacity of different soils across Europe and how it changes over time. Soil monitoring is needed to support evidence-based policies to incentivise sustainable soil management. To this aim, we assessed which soil attributes can be used as potential indicators of five soil functions; (1) primary production, (2) water purification and regulation, (3) carbon sequestration and climate regulation, (4) soil biodiversity and habitat provisioning and (5) recycling of nutrients. We compared this list of attributes to existing national (regional) and EU-wide soil monitoring networks. The overall picture highlighted a clearly unbalanced dataset, in which predominantly chemical soil parameters were included, and soil biological and physical attributes were severely under represented. Methods applied across countries for indicators also varied. At a European scale, the LUCAS-soil survey was evaluated and again confirmed a lack of important soil biological parameters, such as C mineralisation rate, microbial biomass and earthworm community, and soil physical measures such as bulk density. In summary, no current national or European monitoring system exists which has the capacity to quantify the five soil functions and therefore evaluate multi-functional capacity of a soil and in many countries no data exists at all. This paper calls for the addition of soil biological and some physical parameters within the LUCAS-soil survey at European scale and for further development of national soil monitoring schemes.

  17. Extraction behavior of metallic contaminants and soil constituents from contaminated soils.

    PubMed

    Tokunaga, S; Park, S W; Ulmanu, M

    2005-06-01

    With an aim of developing an effective remediation technology for soils contaminated by heavy metals and metalloids, the extraction behavior of metallic contaminants as well as those of soil constituents was studied on a laboratory scale. Three contaminated soils collected from a former metal recycling plant were examined. These three soils were found to be contaminated by As, Cu, Pb, Sb, Se and Zn as compared to the non-contaminated soil. The pH-dependent extraction behavior of various elements from the soils was measured in a wide pH range and categorized into three groups. Hydrochloric acid (HCl), H2SO4, H3PO4, HNO3, sodium citrate, sodium tartrate, disodium dihydrogen ethylenediaminetetraacetate and diethylenetriaminepentaacetic acid were evaluated as extractants for removing contaminants from the soils. Extraction behavior of the soil constituents was also studied. The efficiency of the extraction was evaluated by the Japanese content and leaching tests. The stabilization of Pb remaining in the soil after the extraction process was conducted by the addition of iron(III) and calcium chloride.

  18. Soil Carbon Cycling - More than Changes in Soil Organic Carbon Stocks

    NASA Astrophysics Data System (ADS)

    Lorenz, K.

    2015-12-01

    Discussions about soil carbon (C) sequestration generally focus on changes in soil organic carbon (SOC) stocks. Global SOC mass in the top 1 m was estimated at about 1325 Pg C, and at about 3000 Pg C when deeper soil layers were included. However, both inorganically and organically bound carbon forms are found in soil but estimates on global soil inorganic carbon (SIC) mass are even more uncertain than those for SOC. Globally, about 947 Pg SIC may be stored in the top 1 m, and especially in arid and semi-arid regions SIC stocks can be many times great than SOC stocks. Both SIC and SOC stocks are vulnerable to management practices, and stocks may be enhanced, for example, by optimizing net primary production (NPP) by fertilization and irrigation (especially optimizing belowground NPP for enhancing SOC stocks), adding organic matter (including black C for enhancing SOC stocks), and reducing soil disturbance. Thus, studies on soil C stocks, fluxes, and vulnerability must look at both SIC and SOC stocks in soil profiles to address large scale soil C cycling.

  19. Soil-Plant Nutrient Interactions on Manure-Enriched Calcareous Soils

    USDA-ARS?s Scientific Manuscript database

    Nutrient accumulations on heavily manured soils can trigger soil and plant nutrient interactions. The goal of the study was to determine the current impact of dairy manure applications on nutrient concentrations in soil and tissue for irrigated corn silage crops grown in Southern Idaho. At harvest,...

  20. Using soil health to assess ecotoxicological impacts of pollutants on soil microflora.

    PubMed

    Bécaert, Valérie; Deschênes, Louise

    2006-01-01

    Microorganisms are essential for a properly functioning soil ecosystem. However, few methods allow an ecotoxicological evaluation of pollutant impact on the soil microbial community. This review proposes the use of the concept of soil health as an ecotoxicological evaluation tool for soil microflora. Initially limited to sustainable agriculture, the concept of soil health is now being applied to novel situations including contaminated and remediated soils. A large amount of work has been published in the last few decades on soil health indicators, and a review of the most relevant studies is presented here. The most cited work is that of the S-5518 committee set up in 1997 by the Soil Science Society of America (SSSA), which proposed to define soil quality as being "the capacity of a soil to function within the limits of an ecosystem, to support biological production, to maintain environmental quality and to support fauna and flora health." The soil health indicators reviewed here are the ones based on this definition because it relates well to sustainability and durability of the soil functions. Several indicators proposed in these studies could be employed in the evaluation of the ecotoxicological impact of pollutants on the soil microbial community, including microbial diversity, microbial activity, and functional stability. However, research is still required to unify the concept, to set threshold values, and to standardize methodologies.

  1. The effect of soil type on the bioremediation of petroleum contaminated soils.

    PubMed

    Haghollahi, Ali; Fazaelipoor, Mohammad Hassan; Schaffie, Mahin

    2016-09-15

    In this research the bioremediation of four different types of contaminated soils was monitored as a function of time and moisture content. The soils were categorized as sandy soil containing 100% sand (type I), clay soil containing more than 95% clay (type II), coarse grained soil containing 68% gravel and 32% sand (type III), and coarse grained with high clay content containing 40% gravel, 20% sand, and 40% clay (type IV). The initially clean soils were contaminated with gasoil to the concentration of 100 g/kg, and left on the floor for the evaporation of light hydrocarbons. A full factorial experimental design with soil type (four levels), and moisture content (10 and 20%) as the factors was employed. The soils were inoculated with petroleum degrading microorganisms. Soil samples were taken on days 90, 180, and 270, and the residual total petroleum hydrocarbon (TPH) was extracted using soxhlet apparatus. The moisture content of the soils was kept almost constant during the process by intermittent addition of water. The results showed that the efficiency of bioremediation was affected significantly by the soil type (Pvalue < 0.05). The removal percentage was the highest (70%) for the sandy soil with the initial TPH content of 69.62 g/kg, and the lowest for the clay soil (23.5%) with the initial TPH content of 69.70 g/kg. The effect of moisture content on bioremediation was not statistically significant for the investigated levels. The removal percentage in the clay soil was improved to 57% (within a month) in a separate experiment by more frequent mixing of the soil, indicating low availability of oxygen as a reason for low degradation of hydrocarbons in the clay soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Soils as Sediment database: closing a gap between soil science and geomorphology

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus J.

    2016-04-01

    Soils are an interface between the Earth's spheres and shaped by the nature of the interaction between them. The relevance of soil properties for the nature of the interaction between atmosphere, hydrosphere and biosphere is well-studied and accepted, on point- or ecotone-scale. However, this understanding of the largely vertical connections between spheres is not matched by a similar recognition of soil properties affecting processes acting largely in a lateral way across the land surface, such as erosion, transport and deposition of soil. Key areas where such an understanding is essential are all issues related to the lateral movement of soil-bound substances that affect the nature of soils itself, as well as water or vegetation downslope from the source area. The redistribution of eroded soil falls several disciplines, most notably soil science, agronomy, hydrology and geomorphology. Accordingly, the way sediment is described differs: in soil science, aggregation and structure are essential properties, while most process-based soil erosion models treat soil as a mixture of individual mineral grains, based on concepts derived in fluvial geomorphology or civil engineering. The actual behavior of aggregated sediment is not reflected by either approach and difficult to capture due to the dynamic nature of aggregation, especially in an environment such as running water. Still, a proxy to assess the uncertainties introduced by aggregation on the behavior of soil as sediment would represent a step forward. To develop such a proxy, a database collating relevant soil and sediment properties could serve as an initial step to identify which soil types and erosion scenarios are prone to generate a high uncertainty compared to the use of soil texture in erosion models. Furthermore, it could serve to develop standardized analytical procedures for appropriate description of soil as sediment.

  3. Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content

    Treesearch

    Diego A. Riveros-Iregui; Ryan E. Emanuel; Daniel J. Muth; L. McGlynn Brian; Howard E. Epstein; Daniel L. Welsch; Vincent J. Pacific; Jon M. Wraith

    2007-01-01

    Recent years have seen a growing interest in measuring and modeling soil CO2 efflux, as this flux represents a large component of ecosystem respiration and is a key determinant of ecosystem carbon balance. Process-based models of soil CO2 production and efflux, commonly based on soil temperature, are limited by nonlinearities such as the observed diurnal hysteresis...

  4. Correlations between soil characteristics and radioactivity content of Vojvodina soil.

    PubMed

    Forkapic, S; Vasin, J; Bikit, I; Mrdja, D; Bikit, K; Milić, S

    2017-01-01

    During the years 2001 and 2010, the content of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs in agricultural soil and soil geochemical characteristics were measured on 50 locations in Northern Province of Serbia - Vojvodina. The locations for sampling were selected so that they proportionately represent all geomorphologic units in the region. The content of clay and humus varied within wide limits depending on soil type and influence the activity concentrations of radionuclides. In this paper we analyzed correlations between radionuclides content and geochemical characteristics of the soil. Possible influence of fertilizers on 238 U content in soil was discussed. The main conclusion is that measured maximal activity concentrations for 238 U (87 Bq/kg), 226 Ra (44.7 Bq/kg), 232 Th (55.5 Bq/kg) and 137 Cs (29 Bq/kg) at 30 cm depth could not endanger the safety of food production. The process of genesis of soil and cultivation mode plays a dominant role on the characteristics of the soil. The most significant correlation was found between the activity concentrations of 40 K and clay content in agricultural soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Effect of integrating straw into agricultural soils on soil infiltration and evaporation.

    PubMed

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun; Guo, Yunlong

    2012-01-01

    Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p < 0.05, and with average errors/biases <10%. Straw mixing exhibited the best effect in terms of soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China.

  6. Effect of land use pattern change from paddy soil to vegetable soil on the adsorption-desorption of cadmium by soil aggregates.

    PubMed

    Zhang, Qiu; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Long, Lingzhi; Huang, Mei; Zhai, Xiuqing; Zeng, Guangming

    2017-01-01

    The influence of land use change from paddy soil to vegetable soil on the adsorption-desorption behavior of Cd in soil aggregates and the variation in soil properties were investigated. The vegetable soil was characterized by lower pH, organic matter content, cation exchange capacity (CEC), free iron oxides, manganese oxides, and catalase activity and higher urease activity compared with the paddy soil. In the isothermal adsorption and desorption experiments, the adsorption characteristics of Cd of the two soils could be well described by Langmuir and Freundlich equations. The adsorption capacity of vegetable soil decreased 22.72 %, and the desorption rate increased 35 % with respect to paddy soil. Therefore, conversion from paddy to vegetable field can reduce the adsorption ability to Cd of the soil to a certain extent. Both the two soils reached the maximum adsorption capacity and the minimum desorption rate in the <0.002-mm faction. The adsorption capacity of Cd in paddy and vegetable soils exhibited great reliance on the content of CEC. Desorption rate was negatively correlated with the four indicators: organic matter, CEC, free iron oxides, and manganese oxides, and specific adsorption was primarily controlled by soil organic matter and manganese oxides.

  7. Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

    NASA Astrophysics Data System (ADS)

    Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

    2014-05-01

    One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

  8. Effects of Air Drying on Soil Available Phosphorus in Two Grassland Soils

    NASA Astrophysics Data System (ADS)

    Schaerer, M.; Frossard, E.; Sinaj, S.

    2003-04-01

    Mobilization of P from the soil to ground and surface water is principally determined by the amount of P in the soil and physico-chemical as well as biological processes determining the available P-pool that is in equilibrium with soil solution. Soil available P is commonly estimated on air dry soil using a variety of methods (extraction with water, dilute acids and bases, anion exchange resin, isotopic exchange or infinite sinks). Recently, attempts have been made to use these measurements to define the potential for transport of P from soil to water by overland flow or subsurface flow. The effect of air drying on soil properties in general, and plant nutrient status in particular, have been subject of a number of studies. The main objective of this paper was to evaluate the effect of air-drying on soil properties and available P. For this experiment, grassland soils were sampled on two study sites located on slopes in the watershed of Lake Greifensee, 25 km south-east of Zurich. Both soils (0-4 cm depth) are rich in P with 1.7 and 1.3 g kg-1 total P at site I and site II, respectively. The concentrations on isotopically exchangeable P within 1 minute (E1min, readily available P) for the same depth were also very high, 58 and 27 mg P kg soil-1 for the site I and II, respectively. In the present study both field moist and air dried soil samples were analyzed for microbial P (Pmic), resin extractable P (P_r), isotopically exchangeable P (E1min) and amorphous Al and Fe (Alox, Feox). Generally, the microbial P in field moist soils reached values up to 120 mg P/kg soil, whereas after drying they decreased by 73% in average for both soils. On the contrary to Pmic, available P estimated by different methods strongly increased after drying of the soil samples. The concentration of phosphate ions in the soil solution c_p, E1min and P_r were 4.2, 2.2 and 2 times higher in dry soils than in field moist soils. The increase in available P shows significant semilogarithmic

  9. Geochemistry Of Lead In Contaminated Soils: Effects Of Soil Physico-Chemical Properties

    NASA Astrophysics Data System (ADS)

    Saminathan, S.; Sarkar, D.; Datta, R.; Andra, S. P.

    2006-05-01

    Lead (Pb) is an environmental contaminant with proven human health effects. When assessing human health risks associated with Pb, one of the most common exposure pathways typically evaluated is soil ingestion by children. However, bioaccessibility of Pb primarily depends on the solubility and hence, the geochemical form of Pb, which in turn is a function of site specific soil chemistry. Certain fractions of ingested soil-Pb may not dissociate during digestion in the gastro-intestinal tract, and hence, may not be available for transport across the intestinal membrane. Therefore, this study is being currently performed to assess the geochemical forms and bioaccessibility of Pb in soils with varying physico-chemical properties. In order to elucidate the level of Pb that can be ingested and assimilated by humans, an in-vitro model that simulates the physiological conditions of the human digestive system has been developed and is being used in this study. Four different types of soils from the Immokalee (an acid sandy soil with minimal Pb retention potential), Millhopper (a sandy loam with high Fe/Al content), Pahokee (a muck soil with more than 80% soil organic matter), and Tobosa series (an alkaline soil with high clay content) were artificially contaminated with Pb as lead nitrate at the rate equivalent to 0, 400, 800, and 1200 mg/kg dry soil. Analysis of soils by a sequential extraction method at time zero (immediately after spiking) showed that Immokalee and Millhopper soils had the highest amount of Pb in exchangeable form, whereas Pahokee and Tobosa soils had higher percentages of carbonate-bound and Fe/Al-bound Pb. The results of in-vitro experiment at time zero showed that majority of Pb was dissolved in the acidic stomach environment in Immokalee, Millhopper, and Tobosa, whereas it was in the intestinal phase in Pahokee soils. Because the soil system is not in equilibrium at time zero, the effect of soil properties on Pb geochemistry is not clear as yet. The

  10. Alaskan Arctic Soils: Relationship between Microbial Carbon Usage and Soil Composition

    NASA Astrophysics Data System (ADS)

    Li, H.; Ziolkowski, L. A.

    2015-12-01

    Carbon stored in Arctic permafrost carbon is sensitive to climate change. Microbes are known to degrade Arctic soil organic carbon (OC) and potentially release vast quantitates of CO2 and CH4. Previously, it has been shown that warming of Arctic soils leads to microbes respiring older carbon. To examine this process, we studied the microbial carbon usage and its relationship to the soil OC composition in active layer soils at five locations along a latitudinal transect on the North Slope of Alaska using the compound specific radiocarbon signatures of the viable microbial community using phospholipid fatty acids (PLFA). Additional geochemical parameters (C/N, 13C, 15N and 14C) of bulk soils were measured. Overall there was a greater change with depth than location. Organic rich surface soils are rich in vegetation and have high PLFA based cell densities, while deeper in the active layer geochemical parameters indicated soil OC was degraded and cell densities decreased. As expected, PLFA indicative of Fungi and Protozoa species dominated in surface soils, methyl-branched PLFAs, indicative of bacterial origin, increased in deeper in the active layer. A group of previously unreported PLFAs, believed to correlate to anaerobic microbes, increased at the transition between the surface and deep microbial communities. Cluster analysis based on individual PLFAs of samples confirmed compositional differences as a function of depth dominated with no site to site differences. Radiocarbon data of soil OC and PLFA show the preferential consumption of younger soil OC by microbes at all sites and older OC being eaten in deep soils. However, in deeper soil, where the C/N ratio suggests lower bioavailability, less soil OC was incorporated into the microbes as indicating by greater differences between bulk and PLFA radiocarbon ages.

  11. Effect of soil and cover conditions on soil-water relationships

    Treesearch

    George R., Jr. Trimble; Charles E. Hale; H. Spencer Potter

    1951-01-01

    People who make flood-control surveys for the U.S. Department of Agriculture are concerned with the physical condition of the soils in the watersheds. The condition of the soil determines how fast water moves into and through the soil, and how much water is held in storage. The condition of the soil has a great influence on stream flow, erosion, floods and water supply...

  12. Effect of long-term farming strategies on soil microbiota and soil health

    NASA Astrophysics Data System (ADS)

    Sommermann, Loreen; Babin, Doreen; Sandmann, Martin; Smalla, Kornelia; Schellenberg, Ingo; Grosch, Rita; Geistlinger, Joerg

    2017-04-01

    Increasing food and energy demands have resulted in considerable intensification of farming practices, which brought about severe consequences for agricultural soils, e.g. loss of fertility, erosion and enrichment of soil-borne plant diseases. In order to maintain soil quality and health for the future, the development of more extensive and sustainable farming strategies is urgently needed. The soil microbiome is regarded as a key player in soil ecosystem functions, particularly the natural ability of soils to suppress plant pathogens (suppressiveness). Recent studies showed that soil microbial communities are influenced by agricultural management. To further analyze the effects of farming strategies on soil suppressiveness and plant performance, agricultural soils from three long-term field trials in Thyrow, Bernburg (both in Germany) and Therwil (Switzerland) were sampled and subjected to molecular profiling of soil bacteria and fungi using marker genes and high-throughput amplicon sequencing. Significant effects on bacterial as well as fungal community composition, including plant pathogenic and beneficial taxa, were observed among variants of tillage and crop rotation. The least effect on both communities had fertilization, with no significance between variants. Subsequently, the same soils were subjected to growth chamber pot experiments with lettuce as a model (Lactuca sativa). After a growth period of six weeks significant differences in lettuce shoot and soil microbial biomass were observed among soil samples of the different long-term trials. Furthermore, the lettuce rhizosphere exhibited diverse bacterial community compositions as observed by DGGE (denaturing gradient gel electrophoresis). Using group-specific PCR-DGGE fingerprints, bacterial responders to fertilization, soil management and crop rotation were identified among different taxonomic groups. Currently, bacterial and fungal amplicon sequencing of rhizosphere and bulk soil from these pot

  13. Measuring Soil Moisture in Skeletal Soils Using a COSMOS Rover

    NASA Astrophysics Data System (ADS)

    Medina, C.; Neely, H.; Desilets, D.; Mohanty, B.; Moore, G. W.

    2017-12-01

    The presence of coarse fragments directly influences the volumetric water content of the soil. Current surface soil moisture sensors often do not account for the presence of coarse fragments, and little research has been done to calibrate these sensors under such conditions. The cosmic-ray soil moisture observation system (COSMOS) rover is a passive, non-invasive surface soil moisture sensor with a footprint greater than 100 m. Despite its potential, the COSMOS rover has yet to be validated in skeletal soils. The goal of this study was to validate measurements of surface soil moisture as taken by a COSMOS rover on a Texas skeletal soil. Data was collected for two soils, a Marfla clay loam and Chinati-Boracho-Berrend association, in West Texas. Three levels of data were collected: 1) COSMOS surveys at three different soil moistures, 2) electrical conductivity surveys within those COSMOS surveys, and 3) ground-truth measurements. Surveys with the COSMOS rover covered an 8000-h area and were taken both after large rain events (>2") and a long dry period. Within the COSMOS surveys, the EM38-MK2 was used to estimate the spatial distribution of coarse fragments in the soil around two COSMOS points. Ground truth measurements included coarse fragment mass and volume, bulk density, and water content at 3 locations within each EM38 survey. Ground-truth measurements were weighted using EM38 data, and COSMOS measurements were validated by their distance from the samples. There was a decrease in water content as the percent volume of coarse fragment increased. COSMOS estimations responded to both changes in coarse fragment percent volume and the ground-truth volumetric water content. Further research will focus on creating digital soil maps using landform data and water content estimations from the COSMOS rover.

  14. From soil in art towards Soil Art

    NASA Astrophysics Data System (ADS)

    Feller, C.; Landa, E. R.; Toland, A.; Wessolek, G.

    2015-02-01

    The range of art forms and genres dealing with soil is wide and diverse, spanning many centuries and artistic traditions, from prehistoric painting and ceramics to early Renaissance works in Western literature, poetry, paintings, and sculpture, to recent developments in cinema, architecture and contemporary art. Case studies focused on painting, installation, and cinema are presented with the view of encouraging further exploration of art about, in, with, or featuring soil or soil conservation issues, created by artists, and occasionally scientists, educators or collaborative efforts thereof.

  15. On the role of soil fauna in providing soil functions - a meta study

    NASA Astrophysics Data System (ADS)

    Lang, Birgit; Russell, David J.; Vogel, Hans-Jörg; Wollschläger, Ute

    2017-04-01

    Fertile soils are fundamental for the production of biomass and therefore for the provision of goods such as food or fuel. However, soils are threatened by e.g. land degradation, but once lost their functionality cannot simply be replaced as soils are complex systems developed over long time periods. Thus, to develop strategies for sustainable soil use and management, we need a comprehensive functional understanding of soil systems. To this end, the interdisciplinary research program "Soil as a Natural Resource for the Bio-Economy - BonaRes" was launched by the German Federal Government in 2015. One part of this program is the development of a Knowledge Centre for soil functions and services. As part of the Knowledge Centre, we focus on the identification and quantification of biological drivers of soil functions. Based on a systematic review of existing literature, we assess the importance of different soil faunal groups for the soil functions and processes most relevant to agricultural production (i.e. decomposition, mineralization, soil structuring. Additionally, we investigate direct impacts of soil fauna on soil properties (e.g. aggregation, pore volume). As site specific conditions such as climate, soil type or management practices affect soil fauna and their performance, these responses must also be taken into account. In the end, our findings will be used in the development of modeling tools aiming to predict the impacts of different management measures on soil ecosystem services and functions.

  16. Soil Organic Carbon and Nutrient Dynamics in Reclaimed Appalachian Mine Soil

    NASA Astrophysics Data System (ADS)

    Acton, P.; Fox, J.; Campbell, J. E.; Rowe, H. D.; Jones, A.

    2011-12-01

    Past research has shown that drastically disturbed and degraded soils can offer a high potential for soil organic carbon and aboveground carbon sequestration. Little work has been done on both the functioning of soil carbon accumulation and turnover in reclaimed surface mining soils. Reclamation practices of surface coal mine soils in the Southern Appalachian forest region of the United States emphasizes heavy compaction of surface material to provide slope stability and reduce surface erosion, and topsoil is not typically added. An analysis of the previously collected data has provided a 14 year chronosequence of SOC uptake and development in the soil column and revealed that these soils are sequestering carbon at a rate of 1.3 MgC ha-1 yr-1, which is 1.6 to 3 times less than mining soils reported for other regions. Results of bulk density analysis indicate a contrast between 0 - 10 cm (1.51 g cm-3) and 10 - 50 cm (2.04 g cm-3) depth intervals. Aggregate stability was also quantified as well as dynamic soil texture measurements. With this analysis, it has been established that these soils are well below their potential in terms of the ability to store and cycle carbon and other nutrients as well their ability to sustain a fully-functioning forested ecosystem typical for the region. We are taking an integrated approach that relies on ecological observations for present conditions combined with computational modeling to understand long-term soil organic carbon (SOC) accumulation and turnover in regards to SOC sequestration potential and quantification of specific processes by which these soils develop. A dual-isotope end-member model, utilizing the carbon 13 and nitrogen 15 stable isotopes, is being developed to provide greater input into the mathematical separation of organic carbon derived from new soil inputs and existing coal carbon. Soils from the study sites have been isolated into three distinct size pools, and elemental and isotopic analysis of these samples

  17. [Removal of volatile organic compounds in soils by soil vapor extraction (SVE)].

    PubMed

    Yin, Fu-xiang; Zhang, Sheng-tian; Zhao, Xin; Feng, Ke; Lin, Yu-suo

    2011-05-01

    An experiment study has been carried out to investigate effects of the diameter of soil columns, the size of soil particulate and different contaminants on efficiency of simulated soil vapor extraction (SVE). Experiments with benzene, toluene, ethylbenzene and n-propylbenzene contaminated soils showed that larger bottom area/soil height (S/H) of the columns led to higher efficiency on removal of contaminants. Experiments with contaminated soils of different particulate size showed that the efficiency of SVE decreased with increases in soil particulate size, from 10 mesh to between 20 mesh and 40 mesh and removal of contaminants in soils became more difficult. Experiments with contaminated soils under different ventilation rates suggested that soil vapor extraction at a ventilation rate of 0.10 L x min(-1) can roughly remove most contaminants from the soils. Decreasing of contaminants in soils entered tailing stages after 12 h, 18 h and 48 h for benzene, toluene and ethylbenzene, respectively. Removal rate of TVOCs (Total VOCs) reached a level as high as 99.52%. The results of the experiment have indicated that molecule structure and properties of the VOCs are also important factors which have effects on removal rates of the contaminants. Increases in carbon number on the benzene ring, decreases in vapor pressure and volatile capability resulted in higher difficulties in soil decontamination. n-propylbenzene has a lower vapor pressure than toluene and ethylbenzene which led to a significant retard effect on desorption and volatilization of benzene and ethylbenzene.

  18. Plant species influence on soil C after afforestation of Mediterranean degraded soils

    NASA Astrophysics Data System (ADS)

    Dominguez, Maria T.; García-Vargas, Carlos; Madejón, Engracia; Marañón, Teodoro

    2015-04-01

    Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean

  19. Soil treatment engineering

    NASA Astrophysics Data System (ADS)

    Ivica, Kisic; Zeljka, Zgorelec; Aleksandra, Percin

    2017-10-01

    Soil is loose skin of the Earth, located between the lithosphere and atmosphere, which originated from parent material under the influence of pedogenetic processes. As a conditionally renewable natural resource, soil has a decisive influence on sustainable development of global economy, especially on sustainable agriculture and environmental protection. In recent decades, a growing interest prevails for non-production soil functions, primarily those relating to environmental protection. It especially refers to protection of natural resources whose quality depends directly on soil and soil management. Soil contamination is one of the most dangerous forms of soil degradation with the consequences that are reflected in virtually the entire biosphere, primarily at heterotrophic organisms, and also at mankind as a food consumer. Contamination is correlated with the degree of industrialization and intensity of agrochemical usage. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The negative effects caused by pollution are undeniable: reduced agricultural productivity, polluted water sources and raw materials for food are only a few of the effects of soil degradation, while almost all human diseases (excluding AIDS) may be partly related to the transport of contaminants, in the food chain or the air, to the final recipients - people, plants and animals. The remediation of contaminated soil is a relatively new scientific field which is strongly developing in the last 30 years and becoming a more important subject. In order to achieve quality remediation of contaminated soil it is very important to conduct an inventory as accurately as possible, that is, to determine the current state of soil contamination.

  20. Soil water retention of a bare soil with changing bulk densities

    USDA-ARS?s Scientific Manuscript database

    Tillage changes the bulk density of the soil, lowering the density initially after which it increases as the soil settles. Implications of this for soil water content and soil water potential are obvious, but limited efforts have been made to monitor these changes continuously. We present in-situ me...

  1. Increasing Soil Calcium Availability Alters Forest Soil Carbon Stocks

    NASA Astrophysics Data System (ADS)

    Melvin, A.; Goodale, C. L.

    2011-12-01

    Acid deposition in the Northeastern U.S. has been linked to a loss of soil base cations, especially calcium (Ca). While much research has addressed the effects of Ca depletion on soil and stream acidification, few studies have investigated its effects on ecosystem carbon (C) balance. We studied the long-term effects of increased Ca availability on C cycling in a northern hardwood forest in the Adirondack Park, NY. In 1989, calcium carbonate (lime) was added to ~ 100 ha of the Woods Lake Watershed to ameliorate the effects of soil Ca depletion. An additional 100 ha were maintained as controls. We hypothesized that the lime addition would improve forest health and that this improvement would be evident in increased tree biomass, leaf litter, and fine root production. Within the forest floor, we anticipated that the increased pH associated with liming would stimulate microbial activity resulting in increased decomposition and basal soil respiration, and reduced C stocks. Additionally, we hypothesized that increased Ca availability could enhance Ca-OM complexation in the upper mineral soils, leading to increased C stocks in these horizons. Eighteen years after liming, soil pH and exchangeable Ca pools remained elevated in the forest floor and upper mineral soil of the limed plots. Forest floor C stocks were significantly larger in limed plots (68 vs. 31 t C ha-1), and were driven primarily by greater C accumulation in the forest floor Oa horizon. Mineral soil C stocks did not differ between limed and control soils. Liming did not affect tree growth, however a net decline in biomass was observed across the entire watershed. There was a trend for larger fine root and foliar litter inputs in limed plots relative to controls, but the observed forest floor accumulation appears to be driven primarily by a suppression of decomposition. Liming reduced basal soil respiration rates by 17 and 43 % in the Oe and Oa horizons, respectively. This research suggests that Ca may

  2. Mobility of arsenic and its compounds in soil and soil solution: the effect of soil pretreatment and extraction methods.

    PubMed

    Száková, J; Tlustos, P; Goessler, W; Frková, Z; Najmanová, J

    2009-12-30

    The effect of soil extraction procedures and/or sample pretreatment (drying, freezing of the soil sample) on the extractability of arsenic and its compounds was tested. In the first part, five extraction procedures were compared with following order of extractable arsenic portions: 2M HNO(3)>0.43 M CH(3)COOH>or=0.05 M EDTA>or=Mehlich III (0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA) extraction>water). Additionally, two methods of soil solution sampling were compared, centrifugation of saturated soil and the use of suction cups. The results showed that different sample pretreatments including soil solution sampling could lead to different absolute values of mobile arsenic content in soils. However, the interpretation of the data can lead to similar conclusions as apparent from the comparison of the soil solution sampling methods (r=0.79). For determination of arsenic compounds mild extraction procedures (0.05 M (NH(4))(2)SO(4), 0.01 M CaCl(2), and water) and soil solution sampling using suction cups were compared. Regarding the real soil conditions the extraction of fresh samples and/or in situ collection of soil solution are preferred among the sample pretreatments and/or soil extraction procedures. However, chemical stabilization of the solutions should be allowed and included in the analytical procedures for determination of individual arsenic compounds.

  3. Grey water treatment by the slanted soil system with unsorted soil media.

    PubMed

    Ushijima, Ken; Tanaka, Erina; Suzuki, Laís Yuko; Hijikata, Nowaki; Funamizu, Naoyuki; Ito, Ryusei

    2015-01-01

    This study evaluated the performance of unsorted soil media in the slanted soil treatment system, in terms of removal efficiency in suspended solids (SS), chemical oxygen demand (COD), linear alkylbenzene sulphonate (LAS) and Escherichia coli, and lifetime until clogging occurs. Unsorted soil performed longer lifetime until clogging than sorted fine soil. Removal of SS, COD, and LAS also performed same or better level in unsorted soil than fine soil. As reaction coefficients of COD and LAS were described as a function of the hydraulic loading rate, we can design a slanted soil system according to the expected hydraulic loading rate and the targeted level of COD or LAS in effluent. Regarding bacteria removal, unsorted soil performed sufficient reduction of E. coli for 5 weeks; however, the removal process occurred throughout all four chambers, while that of fine soil occurred in one to two chambers.

  4. EuroSoil2012: Soil science for the benefit of mankind and environment

    USDA-ARS?s Scientific Manuscript database

    EuroSoil2012 was convened in Bari ITALY from 2-6 July 2012 as the 4th International Congress of the European Confederation of Soil Science Societies (ECSSS). The theme of EuroSoil2012 as “soil science for the benefit of mankind and environment” aimed to cover several broad aspects of soil science w...

  5. Effect of biosolid waste compost on soil respiration in salt-affected soils

    NASA Astrophysics Data System (ADS)

    Raya, Silvia; Gómez, Ignacio; García, Fuensanta; Navarro, José; Jordán, Manuel Miguel; Belén Almendro, María; Martín Soriano, José

    2013-04-01

    A great part of mediterranean soils are affected by salinization. This is an important problem in semiarid areas increased by the use of low quality waters, the induced salinization due to high phreatic levels and adverse climatology. Salinization affects 25% of irrigated agriculture, producing important losses on the crops. In this situation, the application of organic matter to the soil is one of the possible solutions to improve their quality. The main objective of this research was to asses the relation between the salinity level (electrical conductivity, EC) in the soil and the response of microbial activity (soil respiration rate) after compost addition. The study was conducted for a year. Soil samples were collected near to an agricultural area in Crevillente and Elche, "El Hondo" Natural Park (Comunidad de Regantes from San Felipe Neri). The experiment was developed to determine and quantify the soil respiration rate in 8 different soils differing in salinity. The assay was done in close pots -in greenhouse conditions- containing soil mixed with different doses of sewage sludge compost (2, 4 and 6%) besides the control. They were maintained at 60% of water holding capacity (WHC). Soil samples were analyzed every four months for a year. The equipment used to estimate the soil respiration was a Bac-Trac and CO2 emitted by the soil biota was measured and quantified by electrical impedance changes. It was observed that the respiration rate increases as the proportion of compost added to each sample increases as well. The EC was incremented in each sampling period from the beginning of the experiment, probably due to the fact that soils were in pots and lixiviation was prevented, so the salts couldńt be lost from soil. Over time the compost has been degraded and, it was more susceptible to be mineralized. Salts were accumulated in the soil. Also it was observed a decrease of microbial activity with the increase of salinity in the soil. Keywords: soil

  6. SOIL BIOLOGY AND ECOLOGY

    EPA Science Inventory

    The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

  7. Clay minerals, metallic oxides and oxy-hydroxides and soil organic carbon distribution within soil aggregates in temperate forest soils

    NASA Astrophysics Data System (ADS)

    Gartzia-Bengoetxea, Nahia; Fernández-Ugalde, Oihane; Virto, Iñigo; Arias-González, Ander

    2017-04-01

    Soil mineralogy is of primary importance for key environmental services provided by soils like carbon sequestration. However, current knowledge on the effects of clay mineralogy on soil organic carbon (SOC) stabilization is based on limited and conflicting data. In this study, we investigated the relationship between clay minerals, metallic oxides and oxy-hydroxides and SOC distribution within soil aggregates in mature Pinus radiata D.Don forest plantations. Nine forest stands located in the same geographical area of the Basque Country (North of Spain) were selected. These stands were planted on different parent material (3 on each of the following: sandstone, basalt and trachyte). There were no significant differences in climate and forest management among them. Moreover, soils under these plantations presented similar content of clay particles. We determined bulk SOC storage, clay mineralogy, the content of Fe-Si-Al-oxides and oxyhydroxides and the distribution of organic C in different soil aggregate sizes at different soil depths (0-5 cm and 5-20 cm). The relationship between SOC and abiotic factors was investigated using a factor analysis (PCA) followed by stepwise regression analysis. Soils developed on sandstone showed significantly lower concentration of SOC (29 g C kg-1) than soils developed on basalts (97 g C kg-1) and trachytes (119 g C kg-1). The soils on sandstone presented a mixed clay mineralogy dominated by illite, with lesser amounts of hydroxivermiculite, hydrobiotite and kaolinite, and a total absence of interstratified chlorite/vermiculite. In contrast, the major crystalline clay mineral identified in the soils developed on volcanic rocks was interstratified chlorite/vermiculite. Nevertheless, no major differences were observed between basaltic and trachytic soils in the clay mineralogy. The selective extraction of Fe showed that the oxalate extractable iron was significantly lower in soils on sandstone (3.7%) than on basalts (11.2%) and

  8. Feedbacks Between Soil Structure and Microbial Activities in Soil

    NASA Astrophysics Data System (ADS)

    Bailey, V. L.; Smith, A. P.; Fansler, S.; Varga, T.; Kemner, K. M.; McCue, L. A.

    2017-12-01

    Soil structure provides the physical framework for soil microbial habitats. The connectivity and size distribution of soil pores controls the microbial access to nutrient resources for growth and metabolism. Thus, a crucial component of soil research is how a soil's three-dimensional structure and organization influences its biological potential on a multitude of spatial and temporal scales. In an effort to understand microbial processes at scale more consistent with a microbial community, we have used soil aggregates as discrete units of soil microbial habitats. Our research has shown that mean pore diameter (x-ray computed tomography) of soil aggregates varies with the aggregate diameter itself. Analyzing both the bacterial composition (16S) and enzyme activities of individual aggregates showed significant differences in the relative abundances of key members the microbial communities associated with high enzyme activities compared to those with low activities, even though we observed no differences in the size of the biomass, nor in the overall richness or diversity of these communities. We hypothesize that resources and substrates have stimulated key populations in the aggregates identified as highly active, and as such, we conducted further research that explored how such key populations (i.e. fungal or bacterial dominated populations) alter pathways of C accumulation in aggregate size domains and microbial C utilization. Fungi support and stabilize soil structure through both physical and chemical effects of their hyphal networks. In contrast, bacterial-dominated communities are purported to facilitate micro- and fine aggregate stabilization. Here we quantify the direct effects fungal versus bacterial dominated communities on aggregate formation (both the rate of aggregation and the quality, quantity and distribution of SOC contained within aggregates). A quantitative understanding of the different mechanisms through which fungi or bacteria shape aggregate

  9. Soil Microbial Forensics.

    PubMed

    Santiago-Rodriguez, Tasha M; Cano, Raúl J

    2016-08-01

    Soil microbial forensics can be defined as the study of how microorganisms can be applied to forensic investigations. The field of soil microbial forensics is of increasing interest and applies techniques commonly used in diverse disciplines in order to identify microbes and determine their abundances, complexities, and interactions with soil and surrounding objects. Emerging new techniques are also providing insights into the complexity of microbes in soil. Soil may harbor unique microbes that may reflect specific physical and chemical characteristics indicating site specificity. While applications of some of these techniques in the field of soil microbial forensics are still in early stages, we are still gaining insight into how microorganisms may be more robustly used in forensic investigations.

  10. [Variations of soil fertility level in red soil region under long-term fertilization].

    PubMed

    Yu, Han-qing; Xu, Ming-gang; Lü, Jia-long; Bao, Yao-xian; Sun, Nan; Gao, Ju-sheng

    2010-07-01

    Based on the long-term (1982-2007) field experiment of "anthropogenic mellowing of raw soil" at the Qiyang red soil experimental station under Chinese Academy of Agricultural Sciences, and by using numerical theory, this paper studied the variations of the fertility level of granite red soil, quaternary red soil, and purple sandy shale soil under six fertilization patterns. The fertilization patterns included non-fertilization (CK), straw-returning without fertilizers (CKR), chemical fertilization (NPK), NPK plus straw-return (NPKR), rice straw application (M), and M plus straw-return (MR). The soil integrated fertility index (IFI) was significantly positively correlated with relative crop yield, and could better indicate soil fertility level. The IFI values of the three soils all were in the order of NPK, NPKR > M, MR > CK, CKR, with the highest value in treatment NPKR (0.77, 0.71, and 0.71 for granite red soil, quaternary red soil, and purple sandy shale soil, respectively). Comparing with that in the treatments of no straw-return, the IFI value in the treatments of straw return was increased by 6.72%-18.83%. A turning point of the IFI for all the three soils was observed at about 7 years of anthropogenic mellowing, and the annual increasing rate of the IFI was in the sequence of purple sandy shale soil (0.016 a(-1)) > quaternary red clay soil (0.011 a(-1)) > granite red soil (0.006 a(-1)). It was suggested that a combined application of organic and chemical fertilizers and/or straw return could be an effective and fast measure to enhance the soil fertility level in red soil region.

  11. Soil Response to Global Change: Soil Process Domains and Pedogenic Thresholds (Invited)

    NASA Astrophysics Data System (ADS)

    Chadwick, O.; Kramer, M. G.; Chorover, J.

    2013-12-01

    The capacity of soil to withstand perturbations, whether driven by climate, land use change, or spread of invasive species, depends on its chemical composition and physical state. The dynamic interplay between stable, well buffered soil process domains and thresholds in soil state and function is a strong determinant of soil response to forcing from global change. In terrestrial ecosystems, edaphic responses are often mediated by availability of water and its flux into and through soils. Water influences soil processes in several ways: it supports biological production, hence proton-donor, electron-donor and complexing-ligand production; it determines the advective removal of dissolution products, and it can promote anoxia that leads microorganisms to utilize alternative electron acceptors. As a consequence climate patterns strongly influence global distribution of soil, although within region variability is governed by other factors such as landscape age, parent material and human land use. By contrast, soil properties can vary greatly among climate regions, variation which is guided by the functioning of a suite of chemical processes that tend to maintain chemical status quo. This soil 'buffering' involves acid-base reactions as minerals weather and oxidation-reduction reactions that are driven by microbial respiration. At the planetary scale, soil pH provides a reasonable indicator of process domains and varies from about 3.5 to10, globally, although most soils lie between about 4.5 and 8.5. Those that are above 7.5 are strongly buffered by the carbonate system, those that are characterized by neutral pH (7.5-6) are buffered by release of non-hydrolyzing cations from primary minerals and colloid surfaces, and those that are <6 are buffered by hydrolytic aluminum on colloidal surfaces. Alkali and alkaline (with the exception of limestone parent material) soils are usually associated with arid and semiarid conditions, neutral pH soils with young soils in both dry

  12. Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

    PubMed Central

    Shangguan, Wei; Gong, Peng; Liang, Lu; Dai, YongJiu; Zhang, Keli

    2014-01-01

    Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and provinces. The land-use effects on different soils were uneven. Anthropogenic soils occupied approximately 12% of the total soil area, which had already replaced the original natural soils. About 7.5% of the natural soil classes in China were in danger of substantial loss, due to the disturbance of agriculture and construction. More than 80% of the endangered soils were unprotected due to the overlook of soil diversity. The protection of soil diversity should be integrated into future conservation activities. PMID:25250394

  13. Soil property effects on wind erosion of organic soils

    USDA-ARS?s Scientific Manuscript database

    Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion r...

  14. Soil Property Effects on Wind Erosion of Organic Soils

    USDA-ARS?s Scientific Manuscript database

    Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion r...

  15. A first attempt to reproduce basaltic soil chronosequences using a process-based soil profile model: implications for our understanding of soil evolution

    NASA Astrophysics Data System (ADS)

    Johnson, M.; Gloor, M.; Lloyd, J.

    2012-04-01

    Soils are complex systems which hold a wealth of information on both current and past conditions and many biogeochemical processes. The ability to model soil forming processes and predict soil properties will enable us to quantify such conditions and contribute to our understanding of long-term biogeochemical cycles, particularly the carbon cycle and plant nutrient cycles. However, attempts to confront such soil model predictions with data are rare, although increasingly more data from chronosquence studies is becoming available for such a purpose. Here we present initial results of an attempt to reproduce soil properties with a process-based soil evolution model similar to the model of Kirkby (1985, J. Soil Science). We specifically focus on the basaltic soils in both Hawaii and north Queensland, Australia. These soils are formed on a series of volcanic lava flows which provide sequences of different aged soils all with a relatively uniform parent material. These soil chronosequences provide a snapshot of a soil profile during different stages of development. Steep rainfall gradients in these regions also provide a system which allows us to test the model's ability to reproduce soil properties under differing climates. The mechanistic, soil evolution model presented here includes the major processes of soil formation such as i) mineral weathering, ii) percolation of rainfall through the soil, iii) leaching of solutes out of the soil profile iv) surface erosion and v) vegetation and biotic interactions. The model consists of a vertical profile and assumes simple geometry with a constantly sloping surface. The timescales of interest are on the order of tens to hundreds of thousand years. The specific properties the model predicts are, soil depth, the proportion of original elemental oxides remaining in each soil layer, pH of the soil solution, organic carbon distribution and CO2 production and concentration. The presentation will focus on a brief introduction of the

  16. Processing data from soil assessment surveys with the computer program SOILS.

    Treesearch

    John W. Hazard; Jeralyn Snellgrove; J. Michael Geist

    1985-01-01

    Program SOILS processes data from soil assessment surveys following a design adopted by the Pacific Northwest Region of the USDA Forest Service. It accepts measurements from line transects and associated soil subsamples and generates estimates of the percentages of the sampled area falling in each soil condition class. Total disturbance is calculated by combining...

  17. Microbial response of an acid forest soil to experimental soil warming

    Treesearch

    S.S. Arnold; I.J. Fernandez; L.E. Rustad; L.M. Zibilske

    1999-01-01

    Effects of increased soil temperature on soil microbial biomass and dehydrogenase activity were examined on organic (O) horizon material in a low-elevation spruce-fir ecosystem. Soil temperature was maintained at 5 °C above ambient during the growing season in the experimental plots, and soil temperature, moisture, microbial biomass, and dehydrogenase activity were...

  18. Measured and simulated soil water evaporation from four Great Plains soils

    USDA-ARS?s Scientific Manuscript database

    The amount of soil water lost during stage one and stage two soil water evaporation is of interest to crop water use modelers. The ratio of measured soil surface temperature (Ts) to air temperature (Ta) was tested as a signal for the transition in soil water evaporation from stage one to stage two d...

  19. Soil carbon sequestration by three perennial legume pastures is greater in deeper soil layers than in the surface soil

    NASA Astrophysics Data System (ADS)

    Guan, X.-K.; Turner, N. C.; Song, L.; Gu, Y.-J.; Wang, T.-C.; Li, F.-M.

    2015-07-01

    Soil organic carbon (SOC) plays a vital role as both a sink for and source of atmospheric carbon. Revegetation of degraded arable land in China is expected to increase soil carbon sequestration, but the role of perennial legumes on soil carbon stocks in semiarid areas has not been quantified. In this study, we assessed the effect of alfalfa (Medicago sativa L.) and two locally adapted forage legumes, bush clover (Lespedeza davurica S.) and milk vetch (Astragalus adsurgens Pall.) on the SOC concentration and SOC stock accumulated annually over a 2 m soil profile, and to estimate the long-term potential for SOC sequestration in the soil under the three forage legumes. The results showed that the concentration of SOC of the bare soil decreased slightly over the 7 years, while 7 years of legume growth substantially increased the concentration of SOC over the 0-2.0 m soil depth measured. Over the 7 year growth period the SOC stocks increased by 24.1, 19.9 and 14.6 Mg C ha-1 under the alfalfa, bush clover and milk vetch stands, respectively, and decreased by 4.2 Mg C ha-1 under bare soil. The sequestration of SOC in the 1-2 m depth of soil accounted for 79, 68 and 74 % of SOC sequestered through the upper 2 m of soil under alfalfa, bush clover and milk vetch, respectively. Conversion of arable land to perennial legume pasture resulted in a significant increase in SOC, particularly at soil depths below 1 m.

  20. Evaluating the Capabilities of Soil Enthalpy, Soil Moisture and Soil Temperature in Predicting Seasonal Precipitation

    NASA Astrophysics Data System (ADS)

    Zhao, Changyu; Chen, Haishan; Sun, Shanlei

    2018-04-01

    Soil enthalpy ( H) contains the combined effects of both soil moisture ( w) and soil temperature ( T) in the land surface hydrothermal process. In this study, the sensitivities of H to w and T are investigated using the multi-linear regression method. Results indicate that T generally makes positive contributions to H, while w exhibits different (positive or negative) impacts due to soil ice effects. For example, w negatively contributes to H if soil contains more ice; however, after soil ice melts, w exerts positive contributions. In particular, due to lower w interannual variabilities in the deep soil layer (i.e., the fifth layer), H is more sensitive to T than to w. Moreover, to compare the potential capabilities of H, w and T in precipitation ( P) prediction, the Huanghe-Huaihe Basin (HHB) and Southeast China (SEC), with similar sensitivities of H to w and T, are selected. Analyses show that, despite similar spatial distributions of H-P and T-P correlation coefficients, the former values are always higher than the latter ones. Furthermore, H provides the most effective signals for P prediction over HHB and SEC, i.e., a significant leading correlation between May H and early summer (June) P. In summary, H, which integrates the effects of T and w as an independent variable, has greater capabilities in monitoring land surface heating and improving seasonal P prediction relative to individual land surface factors (e.g., T and w).

  1. Evaluation of soil quality indicators in paddy soils under different crop rotation systems

    NASA Astrophysics Data System (ADS)

    Nadimi-Goki, Mandana; Bini, Claudio; Haefele, Stephan; Abooei, Monireh

    2013-04-01

    Evaluation of soil quality indicators in paddy soils under different crop rotation systems Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in soil management for agriculture and natural resource protection. This study was conducted to detect the effects of four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators (soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed almost similarly, over five years were selected. Surface soil samples were collected from each four rotation systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3 points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve, for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield. Keywords: Soil quality, Crop Rotation System, Paddy Soils, Italy

  2. The role of soil pH on soil carbonic anhydrase activity

    NASA Astrophysics Data System (ADS)

    Sauze, Joana; Jones, Sam P.; Wingate, Lisa; Wohl, Steven; Ogée, Jérôme

    2018-01-01

    Carbonic anhydrases (CAs) are metalloenzymes present in plants and microorganisms that catalyse the interconversion of CO2 and water to bicarbonate and protons. Because oxygen isotopes are also exchanged during this reaction, the presence of CA also modifies the contribution of soil and plant CO18O fluxes to the global budget of atmospheric CO18O. The oxygen isotope signatures (δ18O) of these fluxes differ as leaf water pools are usually more enriched than soil water pools, and this difference is used to partition the net CO2 flux over land into soil respiration and plant photosynthesis. Nonetheless, the use of atmospheric CO18O as a tracer of land surface CO2 fluxes requires a good knowledge of soil CA activity. Previous studies have shown that significant differences in soil CA activity are found in different biomes and seasons, but our understanding of the environmental and ecological drivers responsible for the spatial and temporal patterns observed in soil CA activity is still limited. One factor that has been overlooked so far is pH. Soil pH is known to strongly influence microbial community composition, richness and diversity in addition to governing the speciation of CO2 between the different carbonate forms. In this study we investigated the CO2-H2O isotopic exchange rate (kiso) in six soils with pH varying from 4.5 to 8.5. We also artificially increased the soil CA concentration to test how pH and other soil properties (texture and phosphate content) affected the relationship between kiso and CA concentration. We found that soil pH was the primary driver of kiso after CA addition and that the chemical composition (i.e. phosphate content) played only a secondary role. We also found an offset between the δ18O of the water pool with which CO2 equilibrates and total soil water (i.e. water extracted by vacuum distillation) that varied with soil texture. The reasons for this offset are still unknown.

  3. Long-term tobacco plantation induces soil acidification and soil base cation loss.

    PubMed

    Zhang, Yuting; He, Xinhua; Liang, Hong; Zhao, Jian; Zhang, Yueqiang; Xu, Chen; Shi, Xiaojun

    2016-03-01

    Changes in soil exchangeable cations relative to soil acidification are less studied particularly under long-term cash crop plantation. This study investigated soil acidification in an Ali-Periudic Argosols after 10-year (2002-2012) long-term continuous tobacco plantation. Soils were respectively sampled at 1933 and 2143 sites in 2002 and 2012 (also 647 tobacco plants), from seven tobacco plantation counties in the Chongqing Municipal City, southwest China. After 10-year continuous tobacco plantation, a substantial acidification was evidenced by an average decrease of 0.20 soil pH unit with a substantial increase of soil sites toward the acidic status, especially those pH ranging from 4.5 to 5.5, whereas 1.93 kmol H(+) production ha(-1) year(-1) was mostly derived from nitrogen (N) fertilizer input and plant N uptake output. After 1 decade, an average decrease of 27.6 % total exchangeable base cations or of 0.20 pH unit occurred in all seven tobacco plantation counties. Meanwhile, for one unit pH decrease, 40.3 and 28.3 mmol base cations kg(-1) soil were consumed in 2002 and 2012, respectively. Furthermore, the aboveground tobacco biomass harvest removed 339.23 kg base cations ha(-1) year(-1) from soil, which was 7.57 times higher than the anions removal, leading to a 12.52 kmol H(+) production ha(-1) year(-1) as the main reason inducing soil acidification. Overall, our results showed that long-term tobacco plantation not only stimulated soil acidification but also decreased soil acid-buffering capacity, resulting in negative effects on sustainable soil uses. On the other hand, our results addressed the importance of a continuous monitoring of soil pH changes in tobacco plantation sites, which would enhance our understanding of soil fertility of health in this region.

  4. Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

    PubMed

    Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

    2018-01-01

    Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Mapping specific soil functions based on digital soil property maps

    NASA Astrophysics Data System (ADS)

    Pásztor, László; Fodor, Nándor; Farkas-Iványi, Kinga; Szabó, József; Bakacsi, Zsófia; Koós, Sándor

    2016-04-01

    Quantification of soil functions and services is a great challenge in itself even if the spatial relevance is supposed to be identified and regionalized. Proxies and indicators are widely used in ecosystem service mapping. Soil services could also be approximated by elementary soil features. One solution is the association of soil types with services as basic principle. Soil property maps however provide quantified spatial information, which could be utilized more versatilely for the spatial inference of soil functions and services. In the frame of the activities referred as "Digital, Optimized, Soil Related Maps and Information in Hungary" (DOSoReMI.hu) numerous soil property maps have been compiled so far with proper DSM techniques partly according to GSM.net specifications, partly by slightly or more strictly changing some of its predefined parameters (depth intervals, pixel size, property etc.). The elaborated maps have been further utilized, since even DOSoReMI.hu was intended to take steps toward the regionalization of higher level soil information (secondary properties, functions, services). In the meantime the recently started AGRAGIS project requested spatial soil related information in order to estimate agri-environmental related impacts of climate change and support the associated vulnerability assessment. One of the most vulnerable services of soils in the context of climate change is their provisioning service. In our work it was approximated by productivity, which was estimated by a sequential scenario based crop modelling. It took into consideration long term (50 years) time series of both measured and predicted climatic parameters as well as accounted for the potential differences in agricultural practice and crop production. The flexible parametrization and multiple results of modelling was then applied for the spatial assessment of sensitivity, vulnerability, exposure and adaptive capacity of soils in the context of the forecasted changes in

  6. Soil-Structural Stability as Affected by Clay Mineralogy, Soil Texture and Polyacrylamide Application

    USDA-ARS?s Scientific Manuscript database

    Soil-structural stability (expressed in terms of aggregate stability and pore size distribution) depends on (i) soil inherent properties, (ii) extrinsic condition prevailing in the soil that may vary temporally and spatially, and (iii) addition of soil amendments. Different soil management practices...

  7. Soil-Bacterium Compatibility Model as a Decision-Making Tool for Soil Bioremediation.

    PubMed

    Horemans, Benjamin; Breugelmans, Philip; Saeys, Wouter; Springael, Dirk

    2017-02-07

    Bioremediation of organic pollutant contaminated soil involving bioaugmentation with dedicated bacteria specialized in degrading the pollutant is suggested as a green and economically sound alternative to physico-chemical treatment. However, intrinsic soil characteristics impact the success of bioaugmentation. The feasibility of using partial least-squares regression (PLSR) to predict the success of bioaugmentation in contaminated soil based on the intrinsic physico-chemical soil characteristics and, hence, to improve the success of bioaugmentation, was examined. As a proof of principle, PLSR was used to build soil-bacterium compatibility models to predict the bioaugmentation success of the phenanthrene-degrading Novosphingobium sp. LH128. The survival and biodegradation activity of strain LH128 were measured in 20 soils and correlated with the soil characteristics. PLSR was able to predict the strain's survival using 12 variables or less while the PAH-degrading activity of strain LH128 in soils that show survival was predicted using 9 variables. A three-step approach using the developed soil-bacterium compatibility models is proposed as a decision making tool and first estimation to select compatible soils and organisms and increase the chance of success of bioaugmentation.

  8. Sorption of Cu and Zn in low organic matter-soils as influenced by soil properties and by the degree of soil weathering.

    PubMed

    Antoniadis, V; Golia, E E

    2015-11-01

    Copper and Zn sorption and desorption, among other factors, depend on soil pH, but in soils with different degree of weathering the role of other soil properties (e.g., oxides content and the level of their crystallinity) has not been thoroughly examined. We conducted batch sorption and desorption tests using 21 low-organic C soils that belonged to the soil orders of Entisols, newly developed soils, Inceptisols, and Alfisols, the most weathered soils. Zinc sorption was lower than that of Cu, and its desorption faster, confirming that it is a highly mobile metal. Alfisols had the weaker affinity for metals, due to the lower soil pH typical of this soil order, but also due to the low reactivity colloids they contained. Correlation analyses showed that Fe oxides in Alfisols increased metal release from soils, while they decreased metal desorption from Entisols. We conclude that in low organic matter-content soils, where the protective role of organic colloids is not to be expected, high soil pH alone is not sufficient to protect against metal contamination, but the degree of soil weathering is also important, due to the dominant role of other mineral phases (here, Fe oxides). Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Soil maps as data input for soil erosion models: errors related to map scales

    NASA Astrophysics Data System (ADS)

    van Dijk, Paul; Sauter, Joëlle; Hofstetter, Elodie

    2010-05-01

    Soil erosion rates depend in many ways on soil and soil surface characteristics which vary in space and in time. To account for spatial variations of soil features, most distributed soil erosion models require data input derived from soil maps. Ideally, the level of spatial detail contained in the applied soil map should correspond to the objective of the modelling study. However, often the model user has only one soil map available which is then applied without questioning its suitability. The present study seeks to determine in how far soil map scale can be a source of error in erosion model output. The study was conducted on two different spatial scales, with for each of them a convenient soil erosion model: a) the catchment scale using the physically-based Limbourg Soil Erosion Model (LISEM), and b) the regional scale using the decision-tree expert model MESALES. The suitability of the applied soil map was evaluated with respect to an imaginary though realistic study objective for both models: the definition of erosion control measures at strategic locations at the catchment scale; the identification of target areas for the definition of control measures strategies at the regional scale. Two catchments were selected to test the sensitivity of LISEM to the spatial detail contained in soil maps: one catchment with relatively little contrast in soil texture, dominated by loess-derived soil (south of the Alsace), and one catchment with strongly contrasted soils at the limit between the Alsatian piedmont and the loess-covered hills of the Kochersberg. LISEM was run for both catchments using different soil maps ranging in scale from 1/25 000 to 1/100 000 to derive soil related input parameters. The comparison of the output differences was used to quantify the map scale impact on the quality of the model output. The sensitivity of MESALES was tested on the Haut-Rhin county for which two soil maps are available for comparison: 1/50 000 and 1/100 000. The order of

  10. Mechanical impedance of soil crusts and water content in loamy soils

    NASA Astrophysics Data System (ADS)

    Josa March, Ramon; Verdú, Antoni M. C.; Mas, Maria Teresa

    2013-04-01

    Soil crust development affects soil water dynamics and soil aeration. Soil crusts act as mechanical barriers to fluid flow and, as their mechanical impedance increases with drying, they also become obstacles to seedling emergence. As a consequence, the emergence of seedling cohorts (sensitive seeds) might be reduced. However, this may be of interest to be used as an effective system of weed control. Soil crusting is determined by several factors: soil texture, rain intensity, sedimentation processes, etc. There are different ways to characterize the crusts. One of them is to measure their mechanical impedance (MI), which is linked to their moisture level. In this study, we measured the evolution of the mechanical impedance of crusts formed by three loamy soil types (clay loam, loam and sandy clay loam, USDA) with different soil water contents. The aim of this communication was to establish a mathematical relationship between the crust water content and its MI. A saturated soil paste was prepared and placed in PVC cylinders (50 mm diameter and 10 mm height) arranged on a plastic tray. Previously the plastic tray was sprayed with a hydrophobic liquid to prevent the adherence of samples. The samples on the plastic tray were left to air-dry under laboratory conditions until their IM was measured. To measure IM, a food texture analyzer was used. The equipment incorporates a mobile arm, a load cell to apply force and a probe. The arm moves down vertically at a constant rate and the cylindrical steel probe (4 mm diameter) penetrates the soil sample vertically at a constant rate. The equipment is provided with software to store data (time, vertical distance and force values) at a rate of up to 500 points per second. Water content in crust soil samples was determined as the loss of weight after oven-drying (105°C). From the results, an exponential regression between MI and the water content was obtained (determination coefficient very close to 1). This methodology allows

  11. Soil texture classification algorithm using RGB characteristics of soil images

    USDA-ARS?s Scientific Manuscript database

    Soil texture has an important influence on agriculture, affecting crop selection, movement of nutrients and water, soil electrical conductivity, and crop growth. Soil texture has traditionally been determined in the laboratory using pipette and hydrometer methods that require a considerable amount o...

  12. Adsorption of perfluorooctane sulfonate on soils: Effects of soil characteristics and phosphate competition.

    PubMed

    Qian, Jin; Shen, Mengmeng; Wang, Peifang; Wang, Chao; Hou, Jun; Ao, Yanhui; Liu, Jingjing; Li, Kun

    2017-02-01

    Perfluorooctane sulfonate (PFOS) is an emerging contaminant, whose presence has been detected in different compartments of the environment in many countries. In this study, the effects of soil characteristics and phosphate competition on the adsorption of PFOS on soils were investigated. Results from batch sorption experiments showed that all the adsorption isotherms of PFOS on three tested soils were nonlinear. In experiments without the addition of phosphate (P) to the soil solution, the Freundlich sorption affinity (K f ) of PFOS on S (original soil), S1 (soil from which soil organic matter (SOM) had been removed), and S2 (soil from which both SOM and ferric oxides had been removed) were 23.13, 10.37 and 15.95, respectively. The results suggested that a high amount of SOM in soil can increase the sorption affinity of PFOS on soils and that a greater amount of ferric oxides can reduce it. The addition of P in the soil solution reduced the K f of PFOS on S, S1, and S2 by approximately 25%, 50%, and 15%, respectively. For the binary system of PFOS and P, soil with higher ferric oxide content showed greater K f reduction after P addition; whereas soil with higher SOM content showed less K f reduction. Our results suggest that for soils dominated by ferric oxides, P is a more effective competitor than PFOS for the adsorption sites in the binary system; whereas in soils containing more SOM, P is a weak competitor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Soil type-depending effect of paddy management: composition and distribution of soil organic matter

    NASA Astrophysics Data System (ADS)

    Urbanski, Livia; Kölbl, Angelika; Lehndorff, Eva; Houtermans, Miriam; Schad, Peter; Zhang, Gang-Lin; Rahayu Utami, Sri; Kögel-Knabner, Ingrid

    2016-04-01

    Paddy soil management is assumed to promote soil organic matter accumulation and specifically lignin caused by the resistance of the aromatic lignin structure against biodegradation under anaerobic conditions during inundation of paddy fields. The present study investigates the effect of paddy soil management on soil organic matter composition compared to agricultural soils which are not used for rice production (non-paddy soils). A variety of major soil types, were chosen in Indonesia (Java), including Alisol, Andosol and Vertisol sites (humid tropical climate of Java, Indonesia) and in China Alisol sites (humid subtropical climate, Nanjing). This soils are typically used for rice cultivation and represent a large range of soil properties to be expected in Asian paddy fields. All topsoils were analysed for their soil organic matter composition by solid-state 13C nuclear magnetic resonance spectroscopy and lignin-derived phenols by CuO oxidation method. The soil organic matter composition, revealed by solid-state 13C nuclear magnetic resonance, was similar for the above named different parent soil types (non-paddy soils) and was also not affected by the specific paddy soil management. The contribution of lignin-related carbon groups to total SOM was similar in the investigated paddy and non-paddy soils. A significant proportion of the total aromatic carbon in some paddy and non-paddy soils was attributed to the application of charcoal as a common management practise. The extraction of lignin-derived phenols revealed low VSC (vanillyl, syringyl, cinnamyl) values for all investigated soils, being typical for agricultural soils. An inherent accumulation of lignin-derived phenols due to paddy management was not found. Lignin-derived phenols seem to be soil type-dependent, shown by different VSC concentrations between the parent soil types. The specific paddy management only affects the lignin-derived phenols in Andosol-derived paddy soils which are characterized by

  14. Determination of chemical availability of cadmium and zinc in soils using inert soil moisture samplers.

    PubMed

    Knight, B P; Chaudri, A M; McGrath, S P; Giller, K E

    1998-01-01

    A rapid method for extracting soil solutions using porous plastic soil-moisture samplers was combined with a cation resin equilibration based speciation technique to look at the chemical availability of metals in soil. Industrially polluted, metal sulphate amended and sewage sludge treated soils were used in our study. Cadmium sulphate amended and industrially contaminated soils all had > 65% of the total soil solution Cd present as free Cd2+. However, increasing total soil Cd concentrations by adding CdSO4 resulted in smaller total soil solution Cd. Consequently, the free Cd2+ concentrations in soil solutions extracted from these soils were smaller than in the same soil contaminated by sewage sludge addition. Amendment with ZnSO4 gave much greater concentrations of free Zn2+ in soil solutions compared with the same soil after long-term Zn contamination via sewage sludge additions. Our results demonstrate the difficulty in comparing total soil solution and free metal ion concentrations for soils from different areas with different physiochemical properties and sources of contamination. However, when comparing the same Woburn soil, Cd was much less available as Cd2+ in soil solution from the CdSO4 amended soils compared with soil contaminated by about 36 years of sewage sludge additions. In contrast, much more Zn was available in soil solution as free Zn2+ in the ZnSO4 amended soils compared with the sewage sludge treated soils.

  15. Soil-plant-microbial relations in hydrothermally altered soils of Northern California

    USGS Publications Warehouse

    Blecker, S.W.; Stillings, L.L.; DeCrappeo, N.M.; Ippolito, J.A.

    2014-01-01

    Soils developed on relict hydrothermally altered soils throughout the Western USA present unique opportunities to study the role of geology on above and belowground biotic activity and composition. Soil and vegetation samples were taken at three unaltered andesite and three hydrothermally altered (acid-sulfate) sites located in and around Lassen VolcanicNational Park in northeastern California. In addition, three different types of disturbed areas (clearcut, thinned, and pipeline) were sampled in acid-sulfate altered sites. Soils were sampled (0–15 cm) in mid-summer 2010 from both under-canopy and between-canopy areas within each of the sites. Soils were analyzed for numerous physical and chemical properties along with soil enzyme assays, C and N mineralization potential, microbial biomass-C and C-substrate utilization. Field vegetation measurements consisted of canopy cover by life form (tree, shrub, forb, and grass), tree and shrub density, and above-ground net primary productivity of the understory. Overall, parameters at the clearcut sites were more similar to the unaltered sites, while parameters at the thinned and pipeline sites were more similar to the altered sites. We employed principal components analysis (PCA) to develop two soil quality indices (SQI) to help quantify the differences among the sites: one based on the correlation between soil parameters and canopy cover, and the second based on six sub-indices. Soil quality indices developed in these systems could provide a means for monitoring and identifying key relations between the vegetation, soils, and microorganisms.

  16. kNOw Soil - kNOw Life: Integrating soil science across disciplines

    NASA Astrophysics Data System (ADS)

    Lindbo, D. L.; Kozlowski, D.; Robinson, C.; Chapman, S.

    2014-12-01

    Teaching primary and secondary school students (K-12) about science and art, although absolutely critical, can be difficult. Teachers have specific standards or subject matters that they are required to cover and often soils and soil science is not included in that list. We have struggled with ways to bring soil science information to the larger audience as the direct approach meets with resistance due to the time commitments to other standards. Our approach now is to use soils as a media or vehicle to teach key concepts in broad subject areas. We have developed several lesson plans in science, geography, math and art that focus on a concept but use soils to convey it. For example students make "mini" monoliths of a state soil. During this exercise students need to use skills in geography to find where their state soil occurs in their state and in the country. They need to understand colors in order to choose the correct colors to use to make their monolith. Finally, they must understand how scales work in order to make the monolith accurate in terms of horizon depths. Throughout the exercise discussion on my certain colors occur in the soil can be discussed. This discussion can lead to a qualitative understanding of chemistry and biology. This presentation will demonstrate this lesson and several others that have been developed and available through the Soil Science Society of America's K12 Education Committee and our International Year of Soil website.

  17. Zinc movement in sewage-sludge-treated soils as influenced by soil properties, irrigation water quality, and soil moisture level

    USGS Publications Warehouse

    Welch, J.E.; Lund, L.J.

    1989-01-01

    A soil column study was conducted to assess the movement of Zn in sewage-sludge-amended soils. Varables investigated were soil properties, irrigation water quality, and soil moisture level. Bulk samples of the surface layer of six soil series were packed into columns, 10.2 cm in diameter and 110 cm in length. An anaerobically digested municipal sewage sludge was incorporated into the top 20 cm of each column at a rate of 300 mg ha-1. The columns were maintained at moisture levels of saturation and unsaturation and were leached with two waters of different quality. At the termination of leaching, the columns were cut open and the soil was sectioned and analyzed. Zinc movement was evaluated by mass balance accounting and correlation and regression analysis. Zinc movement in the unsaturated columns ranged from 3 to 30 cm, with a mean of 10 cm. The difference in irrigation water quality did not have an effect on Zn movement. Most of the Zn applied to the unsaturated columns remained in the sludge-amended soil layer (96.1 to 99.6%, with a mean of 98.1%). The major portion of Zn leached from the sludge-amended soil layer accumulated in the 0- to 3-cm depth (35.7 to 100%, with a mean of 73.6%). The mean final soil pH values decreased in the order: saturated columns = sludge-amended soil layer > untreated soils > unsaturated columns. Total Zn leached from the sludge-amended soil layer was correlated negatively at P = 0.001 with final pH (r = -0.85). Depth of Zn movement was correlated negatively at P = 0.001 with final pH (r = -0.91). Multiple linear regression analysis showed that the final pH accounted for 72% of the variation in the total amounts of Zn leached from the sludge-amended soil layer of the unsaturated columns and accounted for 82% of the variation in the depth of Zn movement among the unsaturated columns. A significant correlation was not found between Zn and organic carbon in soil solutions, but a negative correlation significant at P = 0.001 was found

  18. Obtaining soil hydraulic parameters from data assimilation under different climatic/soil conditions

    USDA-ARS?s Scientific Manuscript database

    Obtaining reliable soil hydraulic properties is essential to correctly simulating soil water content (SWC), which is a key component of countless applications such as agricultural management, soil remediation, aquifer protection, etc. Soil hydraulic properties can be measured in the laboratory; howe...

  19. Evaporative losses from soils covered by physical and different types of biological soil crusts

    USGS Publications Warehouse

    Chamizo, S.; Cantón, Y.; Domingo, F.; Belnap, J.

    2013-01-01

    Evaporation of soil moisture is one of the most important processes affecting water availability in semiarid ecosystems. Biological soil crusts, which are widely distributed ground cover in these ecosystems, play a recognized role on water processes. Where they roughen surfaces, water residence time and thus infiltration can be greatly enhanced, whereas their ability to clog soil pores or cap the soil surface when wetted can greatly decrease infiltration rate, thus affecting evaporative losses. In this work, we compared evaporation in soils covered by physical crusts, biological crusts in different developmental stages and in the soils underlying the different biological crust types. Our results show that during the time of the highest evaporation (Day 1), there was no difference among any of the crust types or the soils underlying them. On Day 2, when soil moisture was moderately low (11%), evaporation was slightly higher in well-developed biological soil crusts than in physical or poorly developed biological soil crusts. However, crust removal did not cause significant changes in evaporation compared with the respective soil crust type. These results suggest that the small differences we observed in evaporation among crust types could be caused by differences in the properties of the soil underneath the biological crusts. At low soil moisture (<6%), there was no difference in evaporation among crust types or the underlying soils. Water loss for the complete evaporative cycle (from saturation to dry soil) was similar in both crusted and scraped soils. Therefore, we conclude that for the specific crust and soil types tested, the presence or the type of biological soil crust did not greatly modify evaporation with respect to physical crusts or scraped soils.

  20. Quantifying the heterogeneity of soil compaction, physical soil properties and soil moisture across multiple spatial scales

    NASA Astrophysics Data System (ADS)

    Coates, Victoria; Pattison, Ian; Sander, Graham

    2016-04-01

    England's rural landscape is dominated by pastoral agriculture, with 40% of land cover classified as either improved or semi-natural grassland according to the Land Cover Map 2007. Since the Second World War the intensification of agriculture has resulted in greater levels of soil compaction, associated with higher stocking densities in fields. Locally compaction has led to loss of soil storage and an increased in levels of ponding in fields. At the catchment scale soil compaction has been hypothesised to contribute to increased flood risk. Previous research (Pattison, 2011) on a 40km2 catchment (Dacre Beck, Lake District, UK) has shown that when soil characteristics are homogeneously parameterised in a hydrological model, downstream peak discharges can be 65% higher for a heavy compacted soil than for a lightly compacted soil. However, at the catchment scale there is likely to be a significant amount of variability in compaction levels within and between fields, due to multiple controlling factors. This research focusses in on one specific type of land use (permanent pasture with cattle grazing) and areas of activity within the field (feeding area, field gate, tree shelter, open field area). The aim was to determine if the soil characteristics and soil compaction levels are homogeneous in the four areas of the field. Also, to determine if these levels stayed the same over the course of the year, or if there were differences at the end of the dry (October) and wet (April) periods. Field experiments were conducted in the River Skell catchment, in Yorkshire, UK, which has an area of 120km2. The dynamic cone penetrometer was used to determine the structural properties of the soil, soil samples were collected to assess the bulk density, organic matter content and permeability in the laboratory and the Hydrosense II was used to determine the soil moisture content in the topsoil. Penetration results show that the tree shelter is the most compacted and the open field area

  1. Micro-scale heterogeneity of soil phosphorus depends on soil substrate and depth

    DOE PAGES

    Werner, Florian; Mueller, Carsten W.; Thieme, Jurgen; ...

    2017-06-09

    Soils comprise various heterogeneously distributed pools of lithogenic, free organic, occluded, adsorbed, and precipitated phosphorus (P) forms, which differ depending on soil forming factors. Small-scale heterogeneity of element distributions recently has received increased attention in soil science due to its influence on soil functions and soil fertility. We investigated the micro-scale distribution of total P and different specific P binding forms in aggregates taken from a high-P clay-rich soil and a low-P sandy soil by combining advanced spectrometric and spectroscopic techniques to introduce new insights on P accessibility and availability in soils. Here we show that soil substrate and soilmore » depth determine micro-scale P heterogeneity in soil aggregates. In P-rich areas of all investigated soil aggregates, P was predominantly co-located with aluminium and iron oxides and hydroxides, which are known to strongly adsorb P. Clay minerals were co-located with P only to a lesser extent. In the low-P topsoil aggregate, the majority of the P was bound organically. Aluminium and iron phosphate predominated in the quartz-rich low-P subsoil aggregate. Sorbed and mineral P phases determined P speciation in the high-P top- and subsoil, and apatite was only detected in the high-P subsoil aggregate. Lastly, our results indicate that micro-scale spatial and chemical heterogeneity of P influences P accessibility and bioavailability.« less

  2. Micro-scale heterogeneity of soil phosphorus depends on soil substrate and depth

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Werner, Florian; Mueller, Carsten W.; Thieme, Jurgen

    Soils comprise various heterogeneously distributed pools of lithogenic, free organic, occluded, adsorbed, and precipitated phosphorus (P) forms, which differ depending on soil forming factors. Small-scale heterogeneity of element distributions recently has received increased attention in soil science due to its influence on soil functions and soil fertility. We investigated the micro-scale distribution of total P and different specific P binding forms in aggregates taken from a high-P clay-rich soil and a low-P sandy soil by combining advanced spectrometric and spectroscopic techniques to introduce new insights on P accessibility and availability in soils. Here we show that soil substrate and soilmore » depth determine micro-scale P heterogeneity in soil aggregates. In P-rich areas of all investigated soil aggregates, P was predominantly co-located with aluminium and iron oxides and hydroxides, which are known to strongly adsorb P. Clay minerals were co-located with P only to a lesser extent. In the low-P topsoil aggregate, the majority of the P was bound organically. Aluminium and iron phosphate predominated in the quartz-rich low-P subsoil aggregate. Sorbed and mineral P phases determined P speciation in the high-P top- and subsoil, and apatite was only detected in the high-P subsoil aggregate. Lastly, our results indicate that micro-scale spatial and chemical heterogeneity of P influences P accessibility and bioavailability.« less

  3. Electrokinetic remediation of fluorine-contaminated soil and its impact on soil fertility.

    PubMed

    Zhou, Ming; Wang, Hui; Zhu, Shufa; Liu, Yana; Xu, Jingming

    2015-11-01

    Compared to soil pollution by heavy metals and organic pollutants, soil pollution by fluorides is usually ignored in China. Actually, fluorine-contaminated soil has an unfavorable influence on human, animals, plants, and surrounding environment. This study reports on electrokinetic remediation of fluorine-contaminated soil and the effects of this remediation technology on soil fertility. Experimental results showed that electrokinetic remediation using NaOH as the anolyte was a considerable choice to eliminate fluorine in contaminated soils. Under the experimental conditions, the removal efficiency of fluorine by the electrokinetic remediation method was 70.35%. However, the electrokinetic remediation had a significant impact on the distribution and concentrations of soil native compounds. After the electrokinetic experiment, in the treated soil, the average value of available nitrogen was raised from 69.53 to 74.23 mg/kg, the average value of available phosphorus and potassium were reduced from 20.05 to 10.39 mg/kg and from 61.31 to 51.58 mg/kg, respectively. Meanwhile, the contents of soil available nitrogen and phosphorus in the anode regions were higher than those in the cathode regions, but the distribution of soil available potassium was just the opposite. In soil organic matter, there was no significant change. These experiment results suggested that some steps should be taken to offset the impacts, after electrokinetic treatment.

  4. Soil carbon sequestration by three perennial legume pastures is greater in deeper soil layers than in the surface soil

    NASA Astrophysics Data System (ADS)

    Guan, X.-K.; Turner, N. C.; Song, L.; Gu, Y.-J.; Wang, T.-C.; Li, F.-M.

    2016-01-01

    Soil organic carbon (SOC) plays a vital role as both a sink for and source of atmospheric carbon. Revegetation of degraded arable land in China is expected to increase soil carbon sequestration, but the role of perennial legumes on soil carbon stocks in semiarid areas has not been quantified. In this study, we assessed the effect of alfalfa (Medicago sativa L.) and two locally adapted forage legumes, bush clover (Lespedeza davurica S.) and milk vetch (Astragalus adsurgens Pall.) on the SOC concentration and SOC stock accumulated annually over a 2 m soil profile. The results showed that the concentration of SOC in the bare soil decreased slightly over the 7 years, while 7 years of legume growth substantially increased the concentration of SOC over the 0-2.0 m soil depth. Over the 7-year growth period the SOC stocks increased by 24.1, 19.9 and 14.6 Mg C ha-1 under the alfalfa, bush clover and milk vetch stands, respectively, and decreased by 4.2 Mg C ha-1 in the bare soil. The sequestration of SOC in the 1-2 m depth of the soil accounted for 79, 68 and 74 % of the SOC sequestered in the 2 m deep soil profile under alfalfa, bush clover and milk vetch, respectively. Conversion of arable land to perennial legume pasture resulted in a significant increase in SOC, particularly at soil depths below 1 m.

  5. Atlas of soil reflectance properties

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Biehl, L. L.; Robinson, B. F.

    1979-01-01

    A compendium of soil spectral reflectance curves together with soil test results and site information is presented in an abbreviated manner listing those soil properties most important in influencing soil reflectance. Results are presented for 251 soils from 39 states and Brazil. A narrative key describes relationships between soil parameters and reflectance curves. All soils are classified according to the U.S. soil taxonomy and soil series name for ease of identification.

  6. SoilGrids250m: Global gridded soil information based on machine learning

    PubMed Central

    Mendes de Jesus, Jorge; Heuvelink, Gerard B. M.; Ruiperez Gonzalez, Maria; Kilibarda, Milan; Blagotić, Aleksandar; Shangguan, Wei; Wright, Marvin N.; Geng, Xiaoyuan; Bauer-Marschallinger, Bernhard; Guevara, Mario Antonio; Vargas, Rodrigo; MacMillan, Robert A.; Batjes, Niels H.; Leenaars, Johan G. B.; Ribeiro, Eloi; Wheeler, Ichsani; Mantel, Stephan; Kempen, Bas

    2017-01-01

    This paper describes the technical development and accuracy assessment of the most recent and improved version of the SoilGrids system at 250m resolution (June 2016 update). SoilGrids provides global predictions for standard numeric soil properties (organic carbon, bulk density, Cation Exchange Capacity (CEC), pH, soil texture fractions and coarse fragments) at seven standard depths (0, 5, 15, 30, 60, 100 and 200 cm), in addition to predictions of depth to bedrock and distribution of soil classes based on the World Reference Base (WRB) and USDA classification systems (ca. 280 raster layers in total). Predictions were based on ca. 150,000 soil profiles used for training and a stack of 158 remote sensing-based soil covariates (primarily derived from MODIS land products, SRTM DEM derivatives, climatic images and global landform and lithology maps), which were used to fit an ensemble of machine learning methods—random forest and gradient boosting and/or multinomial logistic regression—as implemented in the R packages ranger, xgboost, nnet and caret. The results of 10–fold cross-validation show that the ensemble models explain between 56% (coarse fragments) and 83% (pH) of variation with an overall average of 61%. Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%. Improvements can be attributed to: (1) the use of machine learning instead of linear regression, (2) to considerable investments in preparing finer resolution covariate layers and (3) to insertion of additional soil profiles. Further development of SoilGrids could include refinement of methods to incorporate input uncertainties and derivation of posterior probability distributions (per pixel), and further automation of spatial modeling so that soil maps can be generated for potentially hundreds of soil variables. Another area of future research is the development of

  7. SoilGrids250m: Global gridded soil information based on machine learning.

    PubMed

    Hengl, Tomislav; Mendes de Jesus, Jorge; Heuvelink, Gerard B M; Ruiperez Gonzalez, Maria; Kilibarda, Milan; Blagotić, Aleksandar; Shangguan, Wei; Wright, Marvin N; Geng, Xiaoyuan; Bauer-Marschallinger, Bernhard; Guevara, Mario Antonio; Vargas, Rodrigo; MacMillan, Robert A; Batjes, Niels H; Leenaars, Johan G B; Ribeiro, Eloi; Wheeler, Ichsani; Mantel, Stephan; Kempen, Bas

    2017-01-01

    This paper describes the technical development and accuracy assessment of the most recent and improved version of the SoilGrids system at 250m resolution (June 2016 update). SoilGrids provides global predictions for standard numeric soil properties (organic carbon, bulk density, Cation Exchange Capacity (CEC), pH, soil texture fractions and coarse fragments) at seven standard depths (0, 5, 15, 30, 60, 100 and 200 cm), in addition to predictions of depth to bedrock and distribution of soil classes based on the World Reference Base (WRB) and USDA classification systems (ca. 280 raster layers in total). Predictions were based on ca. 150,000 soil profiles used for training and a stack of 158 remote sensing-based soil covariates (primarily derived from MODIS land products, SRTM DEM derivatives, climatic images and global landform and lithology maps), which were used to fit an ensemble of machine learning methods-random forest and gradient boosting and/or multinomial logistic regression-as implemented in the R packages ranger, xgboost, nnet and caret. The results of 10-fold cross-validation show that the ensemble models explain between 56% (coarse fragments) and 83% (pH) of variation with an overall average of 61%. Improvements in the relative accuracy considering the amount of variation explained, in comparison to the previous version of SoilGrids at 1 km spatial resolution, range from 60 to 230%. Improvements can be attributed to: (1) the use of machine learning instead of linear regression, (2) to considerable investments in preparing finer resolution covariate layers and (3) to insertion of additional soil profiles. Further development of SoilGrids could include refinement of methods to incorporate input uncertainties and derivation of posterior probability distributions (per pixel), and further automation of spatial modeling so that soil maps can be generated for potentially hundreds of soil variables. Another area of future research is the development of methods

  8. Evaluation of Assimilated SMOS Soil Moisture Data for US Cropland Soil Moisture Monitoring

    NASA Technical Reports Server (NTRS)

    Yang, Zhengwei; Sherstha, Ranjay; Crow, Wade; Bolten, John; Mladenova, Iva; Yu, Genong; Di, Liping

    2016-01-01

    Remotely sensed soil moisture data can provide timely, objective and quantitative crop soil moisture information with broad geospatial coverage and sufficiently high resolution observations collected throughout the growing season. This paper evaluates the feasibility of using the assimilated ESA Soil Moisture Ocean Salinity (SMOS)Mission L-band passive microwave data for operational US cropland soil surface moisture monitoring. The assimilated SMOS soil moisture data are first categorized to match with the United States Department of Agriculture (USDA)National Agricultural Statistics Service (NASS) survey based weekly soil moisture observation data, which are ordinal. The categorized assimilated SMOS soil moisture data are compared with NASSs survey-based weekly soil moisture data for consistency and robustness using visual assessment and rank correlation. Preliminary results indicate that the assimilated SMOS soil moisture data highly co-vary with NASS field observations across a large geographic area. Therefore, SMOS data have great potential for US operational cropland soil moisture monitoring.

  9. Soil Management Effects on Gas Fluxes from an Organic Soil Agricultural System

    NASA Astrophysics Data System (ADS)

    Jennewein, S. P.; Bhadha, J. H.; Lang, T. A.; Singh, M.; Daroub, S. H.; McCray, M.

    2015-12-01

    The role of soil management on gas flux isn't well understood for Histosols of the Everglades Agricultural Area (EAA) of southern Florida. The region is responsible for roughly half of sugarcane (Saccharum spp. hybrids) production in the USA along with supplying winter vegetable crops to the eastern USA. Future productivity in the EAA is jeopardized by soil subsidence resulting from oxidation of organic matter. Establishing the role of tillage, water-table depth, nitrogen fertilizer, and soil depth on gas flux will help determine how effective various managements are on conserving soil. Ongoing lysimeter and field studies examined effects of management practices (water-table, tillage, and nitrogen fertilizer), and soil depth on, gas emission and microbial biomass. The trials were set in Belle Glade, FL, on Lauderhill muck (Lithic Haplosaprists). Results to be presented include soil microbial biomass and soil gas (CO2, CH4, and N2O) flux. This study provides insight into management effectiveness and agriculture sustainability on shallow muck soils of the EAA and will help farmers mitigate problems associated with soil subsidence and seasonally high water-tables.

  10. From Process Understanding Via Soil Functions to Sustainable Soil Management - A Systemic Approach

    NASA Astrophysics Data System (ADS)

    Wollschlaeger, U.; Bartke, S.; Bartkowski, B.; Daedlow, K.; Helming, K.; Kogel-Knabner, I.; Lang, B.; Rabot, E.; Russell, D.; Stößel, B.; Weller, U.; Wiesmeier, M.; Rabot, E.; Vogel, H. J.

    2017-12-01

    Fertile soils are central resources for the production of biomass and the provision of food and energy. A growing world population and latest climate targets lead to an increasing demand for both, food and bio-energy, which requires preserving and improving the long-term productivity of soils as a bio-economic resource. At the same time, other soil functions and ecosystem services need to be maintained: filter for clean water, carbon sequestration, provision and recycling of nutrients, and habitat for biological activity. All these soil functions result from the interaction of a multitude of physical, chemical and biological processes that are not yet sufficiently understood. In addition, we lack understanding about the interplay between the socio-economic system and the soil system and how soil functions benefit human wellbeing. Hence, a solid and integrated assessment of soil quality requires the consideration of the ensemble of soil functions and its relation to soil management to finally be able to develop site-specific options for sustainable soil management. We present an integrated modeling approach that investigates the influence of soil management on the ensemble of soil functions. It is based on the mechanistic relationships between soil functional attributes, each explained by a network of interacting processes as derived from scientific evidence. As the evidence base required for feeding the model is for the most part stored in the existing scientific literature, another central component of our work is to set up a public "knowledge-portal" providing the infrastructure for a community effort towards a comprehensive knowledge base on soil processes as a basis for model developments. The connection to the socio-economic system is established using the Drivers-Pressures-Impacts-States-Responses (DPSIR) framework where our improved understanding about soil ecosystem processes is linked to ecosystem services and resource efficiency via the soil functions.

  11. [Prediction of soil adsorption coefficients of organic compounds in a wide range of soil types by soil column liquid chromatography].

    PubMed

    Guo, Rongbo; Chen, Jiping; Zhang, Qing; Wu, Wenzhong; Liang, Xinmiao

    2004-01-01

    Using the methanol-water mixtures as mobile phases of soil column liquid chromatography (SCLC), prediction of soil adsorption coefficients (K(d)) by SCLC was validated in a wide range of soil types. The correlations between the retention factors measured by SCLC and soil adsorption coefficients measured by batch experiments were studied for five soils with different properties, i.e., Eurosoil 1#, 2#, 3#, 4# and 5#. The results show that good correlations existed between the retention factors and soil adsorption coefficients for Eurosoil 1#, 2#, 3# and 4#. For Eurosoil 5# which has a pH value of near 3, the correlation between retention factors and soil adsorption coefficients was unsatisfactory using methanol-water as mobile phase of SCLC. However, a good correlation was obtained using a methanol-buffer mixture with pH 3 as the mobile phase. This study proved that the SCLC is suitable for the prediction of soil adsorption coefficients.

  12. Soil Water: Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the fourth of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil water. Upon completing the three day module, the student will be able to classify water as to its presence in the soil, outline the hydrological cycle, list the ways water is lost from the soil,…

  13. Effects of soil tillage on the microwave emission of soils

    NASA Technical Reports Server (NTRS)

    Jackson, T. J.; Koopman, G. J.; Oneill, P. E.; Wang, J. R.

    1985-01-01

    In order to understand the interactions of soil properties and microwave emission better, a series of field experiments were conducted in 1984. Small plots were measured with a truck-mounted passive microwave radiometer operating at 1.4 GHz. These data were collected concurrent with ground observations of soil moisture and bulk density. Treatment effects studied included different soil moisture contents and bulk densities. Evaluations of the data have shown that commonly used models of the dielectric properties of wet soils do not explain the observations obtained in these experiments. This conclusion was based on the fact that the roughness parameters determined through optimization were significantly larger than those observed in similar investigations. These discrepancies are most likely due to the soil structure. Commonly used models assume a homogeneous three phase mixture of soil solids, air and water. Under tilled conditions the soil is actually a two phase mixture of aggregates and voids. Appropriate dielectric models for this tilled condition were evaluated and found to explain the observations. These results indicate that previous conclusions concerning the effects of surface roughness in tilled fields may be incorrect, and they may explain some of the inconsistencies encountered in roughness modeling.

  14. Water movement in stony soils: The influence of stoniness on soil water content profiles

    NASA Astrophysics Data System (ADS)

    Novak, Viliam; Knava, Karol

    2010-05-01

    WATER MOVEMENT IN STONY SOILS: THE INFLUENCE OF STONINESS ON SOIL WATER CONTENT PROFILES Viliam Novák, Karol Kňava Institute of Hydrology, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3, Slovakia, e-mail: novak@uh.savba.sk Soils containing rock fragments are widespread over the world, on Europe such soil account for 30%, 60% in Mediterranean region. In comparison to fine earth soils (soil particles are less then 2 mm) stony soils contain rock fragments characterized by the low retention capacity and hydraulic conductivity. So, for stony soils -in comparison to the fine-earth soils - is typical lower hydraulic conductivity and retention capacity, which lead to the decrease decrease of infiltration rate and low water retention. So, water movement and its modeling in stony soil would differ from fine earth (usually agricultural) soil. The aim of this contribution is to demonstrate the differences in water movement in homogeneous soil (fine earth) and stony soil. The influence of different stoniness on soil water content and soil water dynamics was studied too. Windthrow at High Tatra mountains in Slovakia (November 2004) cleared nearly 12 000 ha of 80 year conifers and this event initiated complex research of windthrow impact on the ecosystem. The important part of this study was water movement in impacted area. Specific feature of the soil in this area was moraine soil consisting of fine earth, characterized as silty sand, with the relative stone content up to 0.49, increasing with depth. Associated phenomenon to the forest clearing is the decrease of rain interception and higher undercanopy precipitation. Conifers interception capacity can be three times higher than low canopy interception, and can reach up to 40% of annual precipitation in Central Europe. Stones in the soil are decreasing infiltration rate, but paradoxically increased understorey precipitation and followingly the increased cumulative infiltration led to the increase of the soil

  15. Changes in soil toxicity by phosphate-aided soil washing: effect of soil characteristics, chemical forms of arsenic, and cations in washing solutions.

    PubMed

    Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile

    2015-01-01

    This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5 M phosphate solution for 2 h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Soil Genesis and Development, Lesson 5 - Soil Geography and Classification

    USDA-ARS?s Scientific Manuscript database

    The system of soil classification developed by the United States Department of Agriculture (USDA) is called Soil Taxonomy. Soil Taxonomy consists of a hierarchy of six levels which, from highest to lowest, are: Order, Suborder, Great Group, Subgroup, family, and series. This lesson will focus on bro...

  17. How do peat type, sand addition and soil moisture influence the soil organic matter mineralization in anthropogenically disturbed organic soils?

    NASA Astrophysics Data System (ADS)

    Säurich, Annelie; Tiemeyer, Bärbel; Don, Axel; Burkart, Stefan

    2017-04-01

    Drained peatlands are hotspots of carbon dioxide (CO2) emissions from agriculture. As a consequence of both drainage induced mineralization and anthropogenic sand mixing, large areas of former peatlands under agricultural use contain soil organic carbon (SOC) at the boundary between mineral and organic soils. Studies on SOC dynamics of such "low carbon organic soils" are rare as the focus of previous studies was mainly either on mineral soils or "true" peat soil. However, the variability of CO2 emissions increases with disturbance and therefore, we have yet to understand the reasons behind the relatively high CO2 emissions of these soils. Peat properties, soil organic matter (SOM) quality and water content are obviously influencing the rate of CO2 emissions, but a systematic evaluation of the hydrological and biogeochemical drivers for mineralization of disturbed peatlands is missing. With this incubation experiment, we aim at assessing the drivers of the high variability of CO2 emissions from strongly anthropogenically disturbed organic soil by systematically comparing strongly degraded peat with and without addition of sand under different moisture conditions and for different peat types. The selection of samples was based on results of a previous incubation study, using disturbed samples from the German Agricultural Soil Inventory. We sampled undisturbed soil columns from topsoil and subsoil (three replicates of each) of ten peatland sites all used as grassland. Peat types comprise six fens (sedge, Phragmites and wood peat) and four bogs (Sphagnum peat). All sites have an intact peat horizon that is permanently below groundwater level and a strongly disturbed topsoil horizon. Three of the fen and two of the bog sites have a topsoil horizon altered by sand-mixing. In addition the soil profile was mapped and samples for the determination of soil hydraulic properties were collected. All 64 soil columns (including four additional reference samples) will be installed

  18. Soil management of copper mine tailing soils--sludge amendment and tree vegetation could improve biological soil quality.

    PubMed

    Asensio, Verónica; Covelo, Emma F; Kandeler, Ellen

    2013-07-01

    Mine soils at the depleted copper mine in Touro (Northwest Spain) are physico-chemically degraded and polluted by chromium and copper. To increase the quality of these soils, some areas at this mine have been vegetated with eucalyptus or pines, amended with sludges, or received both treatments. Four sites were selected at the Touro mine tailing in order to evaluate the effect of these different reclamation treatments on the biological soil quality: (1) Control (untreated), (2) Forest (vegetated), (3) Sludge (amended with sludges) and (4) Forest+Sludge (vegetated and amended). The new approach of the present work is that we evaluated the effect of planting trees or/and amending with sludges on the biological soil quality of mine sites polluted by metals under field conditions. The addition of sludges to mine sites recovered the biological quality of the soil, while vegetating with trees did not increase microbial biomass and function to the level of unpolluted sites. Moreover, amending with sludges increased the efficiency of the soil's microbial community to metabolize C and N, which was indicated by the decrease of the specific enzyme activities and the increase in the ratio Cmic:Nmic (shift towards predominance of fungi instead of bacteria). However, the high Cu and Cr concentrations still have negative influence on the microorganisms in all the treated soils. For the future remediation of mine soils, we recommend periodically adding sludge and planting native legume species. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Scientific support, soil information and education provided by the Austrian Soil Science Society

    NASA Astrophysics Data System (ADS)

    Huber, Sigbert; Baumgarten, Andreas; Birli, Barbara; Englisch, Michael; Tulipan, Monika; Zechmeister-Boltenstern, Sophie

    2015-04-01

    The Austrian Soil Science Society (ASSS), founded in 1954, is a non-profit organisation aiming at furthering all branches of soil science in Austria. The ASSS provides information on the current state of soil research in Austria and abroad. It organizes annual conferences for scientists from soil and related sciences to exchange their recent studies and offers a journal for scientific publications. Annually, ASSS awards the Kubiena Research Prize for excellent scientific studies provided by young scientists. In order to conserve and improve soil science in the field, excursions are organized, also in cooperation with other scientific organisations. Due to well-established contacts with soil scientists and soil science societies in many countries, the ASSS is able to provide its members with information about the most recent developments in the field of soil science. This contributes to a broadening of the current scientific knowledge on soils. The ASSS also co-operates in the organisation of excursions and meetings with neighbouring countries. Several members of the ASSS teach soil science at various Austrian universities. More detail on said conferences, excursions, publications and awards will be given in the presentation. Beside its own scientific journal, published once or twice a year, and special editions such as guidebooks for soil classification, the ASSS runs a website providing information on the Society, its activities, meetings, publications, awards and projects. Together with the Environment Agency Austria the ASSS runs a soil platform on the internet. It is accessible for the public and thus informs society about soil issues. This platform offers a calendar with national and international soil events, contacts of soil related organisations and networks, information on national projects and publications. The society has access to products, information material and information on educational courses. Last but not least information on specific soil

  20. Soil Organic Carbon dynamics in agricultural soils of Veneto Region

    NASA Astrophysics Data System (ADS)

    Bampa, F. B.; Morari, F. M.; Hiederer, R. H.; Toth, G. T.; Giandon, P. G.; Vinci, I. V.; Montanarella, L. M.; Nocita, M.

    2012-04-01

    One of the eight soil threats expressed in the European Commission's Thematic Strategy for Soil Protection (COM (2006)231 final) it's the decline in Soil Organic Matter (SOM). His preservation is recognized as with the objective to ensure that the soils of Europe remain healthy and capable of supporting human activities and ecosystems. One of the key goals of the strategy is to maintain and improve Soil Organic Carbon (SOC) levels. As climate change is identified as a common element in many of the soil threats, the European Commission (EC) intends to assess the actual contribution of the soil protection to climate change mitigation and the effects of climate change on the possible depletion of SOM. A substantial proportion of European land is occupied by agriculture, and consequently plays a crucial role in maintaining natural resources. Organic carbon preservation and sequestration in the EU's agricultural soils could have some potential to mitigate the effects of climate change, particularly linked to preventing certain land use changes and maintaining SOC stocks. The objective of this study is to assess the SOC dynamics in agricultural soils (cropland and grassland) at regional scale, focusing on changes due to land use. A sub-objective would be the evaluation of the most used land management practices and their effect on SOC content. This assessment aims to determine the geographical distribution of the potential GHG mitigation options, focusing on hot spots in the EU, where mitigation actions would be particularly efficient and is linked with the on-going work in the JRC SOIL Action. The pilot area is Veneto Region. The data available are coming from different sources, timing and involve different variables as: soil texture, climate, soil disturbance, managements and nutrients. The first source of data is the LUCAS project (Land Use/Land Cover Area Frame statistical Survey). Started in 2001, the LUCAS project aims to monitor changes in land cover/use and

  1. The Changing Model of Soil

    NASA Astrophysics Data System (ADS)

    Richter, D. D.; Yaalon, D.

    2012-12-01

    The contemporary genetic model of soil is changing rapidly in response to advances in soil science and to human and environmental forcings in the 21st century (Richter and Yaalon, 2012). Three ongoing changes in the model of soil include that: (1) lower soil boundaries are much deeper than the solum, historically the O to B horizons, (2) most soils are polygenetic paleosols, products of soil-forming processes that have ranged widely over soils' lifetimes, and (3) soils are globally human-natural bodies, no longer natural bodies. Together, these changes in the model of soil mean that human forcings are a global wave of soil polygenesis altering fluxes of matter and energy and transforming soil thermodynamics as potentially very deep systems. Because soils are non-linear systems resulting from high-order interactions of physics, chemistry, and biology, trajectories of how human forcings alter soils over decades are not readily predictable and require long-term soil observations. There is much to learn about how soils are changing internally as central components of management systems and externally in relation to wider environments. To be critical, research has been remarkably superficial in studies of soil, reductionist in approach, and lacking in time-series observations of responses to soil management. While this criticism may sound negative, it creates significant opportunities for contemporary soil scientists.

  2. Predicting of soil erosion with regarding to rainfall erosivity and soil erodibility

    NASA Astrophysics Data System (ADS)

    Suif, Zuliziana; Razak, Mohd Amirun Anis Ab; Ahmad, Nordila

    2018-02-01

    The soil along the hill and slope are wearing away due to erosion and it can take place due to occurrence of weak and heavy rainfall. The aim of this study is to predict the soil erosion degree in Universiti Pertahanan Nasional Malaysia (UPNM) area focused on two major factor which is soil erodibility and rainfall erosivity. Soil erodibility is the possibilities of soil to detach and carried away during rainfall and runoff. The "ROM" scale was used in this study to determine the degree of soil erodibility, namely low, moderate, high, and very high. As for rainfall erosivity, the erosive power caused by rainfall that cause soil loss. A daily rainfall data collected from January to April was analyzed by using ROSE index classification to identify the potential risk of soil erosion. The result shows that the soil erodibilty are moderate at MTD`s hill, high at behind of block Lestari and Landslide MTD hill, and critical at behind the mess cadet. While, the highest rainfall erosivity was recorded in March and April. Overall, this study would benefit the organization greatly in saving cost in landslide protection as relevant authorities can take early measures repairing the most affected area of soil erosion.

  3. Effects of different soil management practices on soil properties and microbial diversity

    NASA Astrophysics Data System (ADS)

    Gajda, Anna M.; Czyż, Ewa A.; Dexter, Anthony R.; Furtak, Karolina M.; Grządziel, Jarosław; Stanek-Tarkowska, Jadwiga

    2018-01-01

    The effects of different tillage systems on the properties and microbial diversity of an agricultural soil was investigated. In doing so, soil physical, chemical and biological properties were analysed in 2013-2015, on a long-term field experiment on a loamy sand at the IUNG-PIB Experimental Station in Grabów, Poland. Winter wheat was grown under two tillage treatments: conventional tillage using a mouldboard plough and traditional soil tillage equipment, and reduced tillage based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as a mulch on both treatments. Reduced tillage resulted in increased water content throughout the whole soil profile, in comparison with conventional tillage. Under reduced tillage, the content of readily dispersible clay was also reduced, and, therefore, soil stability was increased in the toplayers, compared with conventional tillage. In addition, the beneficial effects of reduced tillage were reflected in higher soil microbial activity as measured with dehydrogenases and hydrolysis of fluorescein diacetate, compared with conventional tillage. Moreover, the polimerase chain reaction - denaturing gradient gel electrophoresis analysis showed that soil under reduced till-age had greater diversity of microbial communities, compared with conventionally-tilled soil. Finally, reduced tillage increased organic matter content, stability in water and microbial diversity in the top layer of the soil.

  4. Soil water repellency of the artificial soil and natural soil in rocky slopes as affected by the drought stress and polyacrylamide.

    PubMed

    Chen, Zhang; Wang, Ruixin; Han, Pengyuan; Sun, Hailong; Sun, Haifeng; Li, Chengjun; Yang, Lixia

    2018-04-01

    Soil water repellency (SWR) causes reduced soil water storage, enhanced runoff and reduced ecosystem productivity. Therefore, characterization of SWR is a prerequisite for effective environmental management. SWR has been reported under different soils, land uses and regions of the world, particularly in forest land and after wildfires; however, the understanding of this variable in the artificial soil of rocky slope eco-engineering is still rather limited. This study presented the characterization of SWR in the artificial soil affected by the polyacrylamide (PAM) and drought stress. There were two molecular weights of PAM, and the CK was without PAM application. Three types of soil were studied: natural soil and two types of artificial soil which have been sprayed for 1y and 5y, respectively. The drought stress experiments had three drought gradients, lasted for three weeks. Water repellency index (WRI) and soil-water contact angle (β) were determined using intrinsic sorptivity method by measuring the water sorptivity (S W ) and ethanol sorptivity (S E ) in all soil samples. The results showed that (1) Polyacrylamide treatments significantly increased S W by 3% to 38%, and reduced S E by 1% to 15%, WRI by 6% to 38%, β by 3% to 23% compared to the control group. Polyacrylamide treatments also increased water-stable aggregates content and total porosity by 22% to 33%, 11% to 20% relative to the control, while PAM with a higher molecular weight performed best. (2) The interaction between PAM and drought stress had a significant effect on WRI and β for all soil types (P<0.01) while it only had a significant effect on S W and S E for the artificial soil (P<0.01). (3) The artificial soil had a greater WRI and β than the natural soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Soil compaction--indicators for the assessment of harmful changes to the soil in the context of the German Federal Soil Protection Act.

    PubMed

    Lebert, Matthias; Böken, Holger; Glante, Frank

    2007-02-01

    Soil compaction in agriculture induced by large-scale equipment is of growing concern. Heavy wheel loads used in arable cropping have the potential to cause irreversible damage to the subsoil structure and may lead to harmful soil compaction. In order to sustain or improve soil health or fitness on a sustainable basis, indicators are needed to assess the changes in the soil structure and the respective soil functions. This requires an adequate verification of methods for distinguishing between the impairment of soil structure and the disruption of soil functions, and for the respective subject of protection. In this article the link between existing models of soil physical prognosis, practical guidelines, and criteria for the identification of affected soil structure is demonstrated, and a viable concept to distinguish harmful changes to the soil is presented. The concept consists of methods for soil physical analysis such as "pre-compression stress" and "loading ratio", practical recommendations for best management practice, and an indicator-based model for the identification of harmful subsoil compaction derived from a research project for the German Federal Environmental Agency, making it possible to determine for a respective location the required level of action far beyond the common practice of precautions against harmful soil compaction.

  6. Modelling soil-water dynamics in the rootzone of structured and water-repellent soils

    NASA Astrophysics Data System (ADS)

    Brown, Hamish; Carrick, Sam; Müller, Karin; Thomas, Steve; Sharp, Joanna; Cichota, Rogerio; Holzworth, Dean; Clothier, Brent

    2018-04-01

    In modelling the hydrology of Earth's critical zone, there are two major challenges. The first is to understand and model the processes of infiltration, runoff, redistribution and root-water uptake in structured soils that exhibit preferential flows through macropore networks. The other challenge is to parametrise and model the impact of ephemeral hydrophobicity of water-repellent soils. Here we have developed a soil-water model, which is based on physical principles, yet possesses simple functionality to enable easier parameterisation, so as to predict soil-water dynamics in structured soils displaying time-varying degrees of hydrophobicity. Our model, WEIRDO (Water Evapotranspiration Infiltration Redistribution Drainage runOff), has been developed in the APSIM Next Generation platform (Agricultural Production Systems sIMulation). The model operates on an hourly time-step. The repository for this open-source code is https://github.com/APSIMInitiative/ApsimX. We have carried out sensitivity tests to show how WEIRDO predicts infiltration, drainage, redistribution, transpiration and soil-water evaporation for three distinctly different soil textures displaying differing hydraulic properties. These three soils were drawn from the UNSODA (Unsaturated SOil hydraulic Database) soils database of the United States Department of Agriculture (USDA). We show how preferential flow process and hydrophobicity determine the spatio-temporal pattern of soil-water dynamics. Finally, we have validated WEIRDO by comparing its predictions against three years of soil-water content measurements made under an irrigated alfalfa (Medicago sativa L.) trial. The results provide validation of the model's ability to simulate soil-water dynamics in structured soils.

  7. Tolerable soil erosion in Europe

    NASA Astrophysics Data System (ADS)

    Verheijen, Frank; Jones, Bob; Rickson, Jane; Smith, Celina

    2010-05-01

    Soil loss by erosion has been identified as an important threat to soils in Europe* and is recognised as a contributing process to soil degradation and associated deterioration, or loss, of soil functioning. From a policy perspective, it is imperative to establish well-defined baseline values to evaluate soil erosion monitoring data against. For this purpose, accurate baseline values - i.e. tolerable soil loss - need to be differentiated at appropriate scales for monitoring and, ideally, should take soil functions and even changing environmental conditions into account. The concept of tolerable soil erosion has been interpreted in the scientific literature in two ways: i) maintaining the dynamic equilibrium of soil quantity, and ii) maintaining biomass production, at a location. The first interpretation ignores soil quality by focusing only on soil quantity. The second approach ignores many soil functions by focusing only on the biomass (particularly crop) production function of soil. Considering recognised soil functions, tolerable soil erosion may be defined as 'any mean annual cumulative (all erosion types combined) soil erosion rate at which a deterioration or loss of one or more soil functions does not occur'. Assumptions and problems of this definition will be discussed. Soil functions can generally be judged not to deteriorate as long as soil erosion does not exceed soil formation. At present, this assumption remains largely untested, but applying the precautionary principle appears to be a reasonable starting point. Considering soil formation rates by both weathering and dust deposition, it is estimated that for the majority of soil forming factors in most European situations, soil formation rates probably range from ca. 0.3 - 1.4 t ha-1 yr-1. Although the current agreement on these values seems relatively strong, how the variation within the range is spatially distributed across Europe and how this may be affected by climate, land use and land management

  8. Mineral Control of Soil Carbon Dynamics in Forest Soils: A Lithosequence Under Ponderosa Pine

    NASA Astrophysics Data System (ADS)

    Heckman, K. A.; Welty-Bernard, A.; Rasmussen, C.; Schwartz, E.; Chorover, J.

    2008-12-01

    The role of soil organic carbon in regulating atmospheric CO2 concentration has spurred interest in both quantifying existing soil C stocks and modeling the behavior of soil C under climate change scenarios. Soil parent material exerts direct control over soil organic carbon content through its influence on soil pH and mineral composition. Soil acidity and mineral composition also influence soil microbial community composition and activity, thereby controlling soil respiration rates and microbial biomass size. We sampled a lithosequence of four parent materials (rhyolite, granite, basalt, limestone) under Pinus ponderosa to examine the effects of soil mineralogy and acidity on soil organic carbon content and soil microbial community. Three soil profiles were examined on each parent material and analyzed by X-ray diffraction, pH, selective dissolution, C and N content, and 13C signature. Soils from each of the four parent materials were incubated for 40 days, and microbial communities were compared on the basis of community composition (as determined through T-RFLP analysis), specific metabolic activity, biomass, δ13C of respired CO2, and cumulative amount of C mineralized over the course of the incubation. Soil C content varied significantly among soils of different parent material, and was strongly and positively associated with the abundance of Al-humus complexes r2 = 0.71; P < 0.0001, Fe-humus complexes r2 = 0.74; P = 0.0003, and crystalline Fe-oxide content r2 = 0.63; P = 0.0023. Microbial community composition varied significantly among soils and showed strong associations with soil pH 1:1 in KCl; r2 = 0.87; P < 0.0001, concentration of exchangeable Al r2 = 0.81; P < 0.0001, amorphous Fe oxide content r2 = 0.59; P < 0.004, and Al-humus content r2 = 0.35; P < 0.04. Mineralization rates, biomass and δ13C of respired CO2 differed among parent materials, and also varied with incubation time as substrate quality and N availability changed. The results demonstrate

  9. Changes in photosynthesis and soil moisture drive the seasonal soil respiration-temperature hysteresis relationship

    USDA-ARS?s Scientific Manuscript database

    In nearly all large-scale models, CO2 efflux from soil (i.e., soil respiration) is represented as a function of soil temperature. However, the relationship between soil respiration and soil temperature is highly variable at the local scale, and there is often a pronounced hysteresis in the soil resp...

  10. [Effect of Biochar Application on Soil Aggregates Distribution and Moisture Retention in Orchard Soil].

    PubMed

    An, Yan; Ji, Qiang; Zhao, Shi-xiang; Wang, Xu-dong

    2016-01-15

    Applying biochar to soil has been considered to be one of the important practices in improving soil properties and increasing carbon sequestration. In order to investigate the effects of biochar application on soil aggregates distribution and its organic matter content and soil moisture constant in different size aggregates, various particle-size fractions of soil aggregates were obtained with the dry-screening method. The results showed that, compared to the treatment without biochar (CK), the application of biochar reduced the mass content of 5-8 mm and < 0.25 mm soil aggregates at 0-10 cm soil horizon, while increased the content of 1-2 mm and 2-5 mm soil aggregates at this horizon, and the content of 1-2 mm aggregates significantly increased along with the rates of biochar application. The mean diameter of soil aggregates was reduced by biochar application at 0-10 cm soil horizon. However, the effect of biochar application on the mean diameter of soil aggregates at 10-20 cm soil horizon was not significant. Compared to CK, biochar application significantly increased soil organic carbon content in aggregates, especially in 1-2 mm aggregates which was increased by > 70% compared to CK. Both the water holding capacity and soil porosity were significantly increased by biochar application. Furthermore, the neutral biochar was more effective than alkaline biochar in increasing soil moisture.

  11. Using soil properties to predict in vivo bioavailability of lead in soils.

    PubMed

    Wijayawardena, M A Ayanka; Naidu, Ravi; Megharaj, Mallavarapu; Lamb, Dane; Thavamani, Palanisami; Kuchel, Tim

    2015-11-01

    Soil plays a significant role in controlling the potential bioavailability of contaminants in the environment. In this study, eleven soils were used to investigate the relationship between soil properties and relative bioavailability (RB) of lead (Pb). To minimise the effect of source of Pb on in vivo bioavailability, uncontaminated study soils were spiked with 1500 mg Pb/kg soil and aged for 10-12 months prior to investigating the relationships between soil properties and in vivo RB of Pb using swine model. The biological responses to oral administration of Pb in aqueous phase or as spiked soils were compared by applying a two-compartment pharmacokinetic model to blood Pb concentration. The study revealed that RB of Pb from aged soils ranged from 30±9% to 83±7%. The very different RB of Pb in these soils was attributed to variations in the soils' physico-chemical properties. This was established using sorption studies showing: firstly, Freundlich partition coefficients that ranged from 21 to 234; and secondly, a strongly significant (R(2)=0.94, P<0.001) exponential relationship between RB and Freundlich partition coefficient (Kd). This simple exponential model can be used to predict relative bioavailability of Pb in contaminated soils. To the best of our knowledge, this is the first such model derived using sorption partition coefficient to predict the relative bioavailability of Pb. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Soil phosphorus - new insights into a critical cycle across many soil functions

    NASA Astrophysics Data System (ADS)

    Leinweber, Peter; Zimmer, Dana

    2017-04-01

    The fate of phosphorus (P-) compounds in the soil - plant - water - system is linked with most soil functions such as productivity for agricultural crops, reactor for nutrient cycling, filter and buffer for water, and biodiversity. The P-compounds, mostly phosphates in a multitude of chemical bonds, may have contradicting influences on soil functions. For instance, P-concentrations may be suboptimal for crop yields but at the same time exceeding the soil filter/buffer capacity for water resources. Modern agriculture has increased this misbalance. Therefore, a better soil P management that balances all soil functions requires a deeper understanding of the P-cycling in the environment. The collaborative project "InnoSoilPhos" in the frame of the BonaRes-program of the German Federal Ministry of Education and Research (BMBF) aims at disclosing the chemical composition, biogeochemical transformations and microbiological fundamentals of P-cycling and P-transport processes across all relevant scales from atomic to catchment and landscapes. The contribution will give an overview on the project and some examples for the latest findings on P-reactions at mineral surfaces (experimental and theoretical), microorganism diversity involved in soil P-transformations, crop yield responses to P-fertilizer regimes (including new P-recycling products) and, finally, hot spots and hot moments of P-release from soils into adjoining freshwater systems. These findings allow some preliminary demands and frame conditions for an improved soil P management to better balance the soil functions and safe the global mineable P resources.

  13. Soil formation: Chapter 6

    USGS Publications Warehouse

    Goldhaber, Martin B.; Banwart, Steven A.

    2015-01-01

    Soil formation reflects the complex interaction of many factors, among the most important of which are (i) the nature of the soil parent material, (ii) regional climate, (iii) organisms, including humans, (iv) topography and (v) time. These processes operate in Earth's critical zone; the thin veneer of our planet where rock meets life. Understanding the operation of these soil-forming factors requires an interdisciplinary approach and is a necessary predicate to charactering soil processes and functions, mitigating soil degradation and adapting soil management to environmental change. In this chapter, we discuss how these soil-forming factors operate both singly and in concert in natural and human modified environments. We emphasize the role that soil organic matter plays in these processes to provide context for understanding the benefits that it bestows on humanity.

  14. Biochar Amendment to the Soil Surface Reduces Fumigant Emissions and Enhances Soil Microorganism Recovery.

    PubMed

    Shen, Guoqing; Ashworth, Daniel J; Gan, Jay; Yates, Scott R

    2016-02-02

    During soil fumigation, it is ideal to mitigate soil fumigant emissions, ensure pest control efficacy, and speed up the recovery of the soil microorganism population established postapplication. However, no current fumigant emission reduction strategy can meet all these requirements. In the present study, replicated soil columns were used to study the effect of biochar derived from rice husk (BR) and green waste (BG) applied to the soil surface on 1,3-dichloropropene (1,3-D) and chloropicrin (CP) emissions and soil gas distribution, and on microorganism population re-establishment. Relative to fumigated bare soil (no emission reduction strategy), high-density polyethylene (HDPE), and ammonium thiosulfate (ATS) treatments, BR gave dramatic emission reductions for both fumigants with no obvious emission peak, whereas BG was very effective only for 1,3-D. With BR application, the concentration of fumigant in the soil gas was higher than in the bare soil and ATS treatment. After the soil column experiment, mixing the BR with the fumigated soil resulted in higher soil respiration rates than were observed for HDPE and ATS treatments. Therefore, biochar amendment to the soil surface may be an effective strategy for fumigant emission reduction and the recovery of soil microorganism populations established postapplication.

  15. Dissolved organic carbon in soil solution of peat-moorsh soils on Kuwasy Mire

    NASA Astrophysics Data System (ADS)

    Jaszczyński, J.; Sapek, A.

    2009-04-01

    Key words: peat-moorsh soils, soil solution, dissolved organic carbon (DOC), temperature of soil, redox potential. The objective this study was the dissolved organic carbon concentration (DOC) in soil solution on the background of soil temperature, moisture and redox potential. The investigations were localized on the area of drained and agricultural used Kuwasy Mire, which are situated in the middle basin of Biebrza River, in North-East Poland. Research point was placed on a low peat soil of 110 cm depth managed as extensive grassland. The soil was recognized as peat-moorsh with the second degree of the moorshing process (with 20 cm of moorsh layer). The ceramic suction cups were installed in three replications at 30 cm depth of soil profile. The soil solution was continuously sampled by pomp of the automatic field station. The successive samples comprised of solution collected at the intervals of 21 days. Simultaneously, at the 20, 30 and 40 cm soil depths the measurements of temperature and determination of soil moisture and redox potential were made automatically. The mean twenty-four hours data were collected. The concentrations of DOC were determined by means of the flow colorimeter using the Skalar standard methods. Presented observations were made in 2001-2006. Mean DOC concentration in soil solution was 66 mg.dm-3 within all research period. A significant positive correlation between studied compound concentration and temperature of soil at 30 cm depth was observed; (correlation coefficient - r=0.55, number of samples - n=87). The highest DOC concentrations were observed during the season from July to October, when also a lower ground water level occurred. The DOC concentration in soil solution showed as well a significant correlation with the soil redox potential at 20 cm level. On this depth of describing soil profile a frontier layer between moorshing layer and peat has been existed. This layer is the potentially most active in the respect to

  16. Deep horizons: Soil Carbon sequestration and storage potential in grassland soils

    NASA Astrophysics Data System (ADS)

    Torres-Sallan, Gemma; Schulte, Rogier; Lanigan, Gary J.; Byrne, Kenneth A.; Reidy, Brian; Creamer, Rachel

    2016-04-01

    Soil Organic Carbon (SOC) enhances soil fertility, holding nutrients in a plant-available form. It also improves aeration and water infiltration. Soils are considered a vital pool for C (Carbon) sequestration, as they are the largest pool of C after the oceans, and contain 3.5 more C than the atmosphere. SOC models and inventories tend to focus on the top 30 cm of soils, only analysing total SOC values. Association of C with microaggregates (53-250 μm) and silt and clay (<53 μm) is considered C sequestration as these fractions offer the greatest protection against mineralization. This study assessed the role of aggregation in C sequestration throughout the profile, down to 1 m depth, of 30 grassland sites divided in 6 soil types. One kg sample was collected for each horizon, sieved at 8 mm and dried at 40 °C. Through a wet sieving procedure, four aggregate sizes were isolated: large macroaggregates (>2000 μm); macroaggregates (250-2000 μm); microaggregates and silt & clay. Organic C associated to each aggregate fraction was analysed on a LECO combustion analyser. Sand-free C was calculated for each aggregate size. For all soil types, 84% of the SOC located in the first 30 cm was contained inside macroaggregates and large macroaggregates. Given that this fraction has a turnover time of 1 to 10 years, sampling at that depth only provides information on the labile fraction in soil, and does not consider the longer term C sequestration potential. Only when looking at the whole profile, two clear trends could be observed: 1) soils with a clay increase at depth had most of their C located in the silt and clay fractions, which indicate their enhanced C sequestration capacity, 2) free-draining soils had a bigger part of their SOC located in the macroaggregate fractions. These results indicate that current C inventories and models that focus on the top 30 cm, do not accurately measure soil C sequestration potential in soils, but rather the more labile fraction. However

  17. Aggregate Stability and Erodibility of Purple Soil on Sloping Farmland as affected by different Soil Thickness

    NASA Astrophysics Data System (ADS)

    Huang, Xinjun; Zhang, Qingwen; Chen, Shanghong; Dong, Yuequn; Xiao, Meijia; Hamed, Lamy Mamdoh Mohamed

    2017-04-01

    Soil thickness is basic limiting condition for purple soil, not only due to its effect on crop production, but also its effect on soil structure. Steady-state of soil thickness will be achieved over time, as result the soil aggregate which the key factor of soil erodibility can be enhanced as well. However, the effect of soil thickness on aggregates stability and the characteristics of soil erodibility in sloping land have not yet fully understood.A field survey was conducted in hilly area of Sichuan region located in southeast China to study the relationship between soil aggregate stability and soil erodibility on sloping farmland under different four thickness (100cm, 80cm, 60cm, 30cm) of purple soil. Based on two different sieving methods (Dry and Wet sieving), we analyzed soil aggregate stability and its effect on soil erodibility within depth of 0-30cm soil layers. The results indicated that: Water stable aggregate on sloping farmland was ranged between 37.9% to 58.6%, where it increased with increasing the soil thickness. Moreover, fractal dimension calculated from dry-sieving and wet-sieving was 2.06-2.49 and 2.70-2.85 respectively, where it decreased with decreasing the soil thickness. The overall soil erodibility was 0.05-1.00 and a negative significant correlation was found between soil aggregate stability and erodibility(P<0.01). Moreover, farmland with thick soil profile tended to be high in soil erodibility within the top soil layer (0-30cm). The results reveal that soil thickness can affect soil aggregate stability as well as erodibility. As soil thickness increased, the top soil became more stable and less erodible. Keywords:purple soil; soil thickness; soil aggregate;soil erodibility

  18. Education on sustainable soil management for the masses? The Soil4Life MOOC

    NASA Astrophysics Data System (ADS)

    Maroulis, Jerry; Demie, Moore; Riksen, Michel; Ritsema, Coen

    2017-04-01

    Although soil is one of our most important natural resources and the foundation for all life on Earth it remains one of the most neglected of our resources. We, in soil science know this, but what do we do to reach more people more quickly? MOOCs, 'Massive Open Online Courses', are a vehicle for offering learning to virtually unlimited audiences at little cost to the student. Could MOOCs be the format for introducing more people worldwide to the importance of soil and sustainable soil management? MOOCs have their limitations and critics. However, depending on your goals, expectations and resources, they are a means for getting information to a much broader population than is possible through conventional educational formats. Wageningen University (WU) agreed and approved the development of a MOOC on sustainable soil management entitled Soil4Life. This presentation reviews the format and results of Soil4Life, concluding with some observations and reflections about this approach to soil science education. The Soil4Life MOOC introduces the role of soil in life on earth, soil degradation, and socio-economic issues related to generating action for long-term sustainability of the many soil-related ecosystem services. The objectives of Soil4Life are to raise awareness about the many important aspects of soil and sustainable soil management, and to allow the educational materials we produced to be available for use by others. The process of creating the Soil4Life MOOC involved 18 academic staff across all WU soil-related groups plus a vital team of education and technical staff. This number of people posed various challenges. However, with clear guidelines, lots of encouragement and technical support, Soil4Life was started in late 2015 and launched on the edx platform in May 2016. Just over 5000 students from 161 countries enrolled in the first offer of the Soil4Life MOOC - a modest number for MOOCs, but not bad for soil science. The targeted audience was initially high

  19. Soil science. Soil and human security in the 21st century.

    PubMed

    Amundson, Ronald; Berhe, Asmeret Asefaw; Hopmans, Jan W; Olson, Carolyn; Sztein, A Ester; Sparks, Donald L

    2015-05-08

    Human security has and will continue to rely on Earth's diverse soil resources. Yet we have now exploited the planet's most productive soils. Soil erosion greatly exceeds rates of production in many agricultural regions. Nitrogen produced by fossil fuel and geological reservoirs of other fertilizers are headed toward possible scarcity, increased cost, and/or geopolitical conflict. Climate change is accelerating the microbial release of greenhouse gases from soil organic matter and will likely play a large role in our near-term climate future. In this Review, we highlight challenges facing Earth's soil resources in the coming century. The direct and indirect response of soils to past and future human activities will play a major role in human prosperity and survival. Copyright © 2015, American Association for the Advancement of Science.

  20. Effects of different mechanized soil fertilization methods on corn soil fertility under continuous cropping

    NASA Astrophysics Data System (ADS)

    Shi, Qingwen; Wang, Huixin; Bai, Chunming; Wu, Di; Song, Qiaobo; Gao, Depeng; Dong, Zengqi; Cheng, Xin; Dong, Qiping; Zhang, Yahao; Mu, Jiahui; Chen, Qinghong; Liao, Wenqing; Qu, Tianru; Zhang, Chunling; Zhang, Xinyu; Liu, Yifei; Han, Xiaori

    2017-05-01

    Experiments for mechanized soil fertilization for corns were conducted in Faku demonstration zone. On this basis, we studied effects on corn soil fertility under continuous cropping due to different mechanized soil fertilization methods. Our study would serve as a theoretical basis further for mechanized soil fertilization improvement and soil quality improvement in brown soil area. Based on the survey of soil physical characteristics during different corn growth periods, we collected soil samples from different corn growth periods to determine and make statistical analysis accordingly. Stalk returning to field with deep tillage proved to be the most effective on available nutrient improvement for arable soil in the demonstration zone. Different mechanized soil fertilization methods were remarkably effective on total phosphorus improvement for arable soil in the demonstration zone, while less effective on total nitrogen or total potassium, and not so effective on C/N ratio in soil. Stalk returning with deep tillage was more favorable to improve content of organic matter in soil, when compared with surface application, and organic granular fertilizer more favorable when compared with decomposed cow dung for such a purpose, too.

  1. Multiscale soil moisture estimates using static and roving cosmic-ray soil moisture sensors

    NASA Astrophysics Data System (ADS)

    McJannet, David; Hawdon, Aaron; Baker, Brett; Renzullo, Luigi; Searle, Ross

    2017-12-01

    Soil moisture plays a critical role in land surface processes and as such there has been a recent increase in the number and resolution of satellite soil moisture observations and the development of land surface process models with ever increasing resolution. Despite these developments, validation and calibration of these products has been limited because of a lack of observations on corresponding scales. A recently developed mobile soil moisture monitoring platform, known as the rover, offers opportunities to overcome this scale issue. This paper describes methods, results and testing of soil moisture estimates produced using rover surveys on a range of scales that are commensurate with model and satellite retrievals. Our investigation involved static cosmic-ray neutron sensors and rover surveys across both broad (36 × 36 km at 9 km resolution) and intensive (10 × 10 km at 1 km resolution) scales in a cropping district in the Mallee region of Victoria, Australia. We describe approaches for converting rover survey neutron counts to soil moisture and discuss the factors controlling soil moisture variability. We use independent gravimetric and modelled soil moisture estimates collected across both space and time to validate rover soil moisture products. Measurements revealed that temporal patterns in soil moisture were preserved through time and regression modelling approaches were utilised to produce time series of property-scale soil moisture which may also have applications in calibration and validation studies or local farm management. Intensive-scale rover surveys produced reliable soil moisture estimates at 1 km resolution while broad-scale surveys produced soil moisture estimates at 9 km resolution. We conclude that the multiscale soil moisture products produced in this study are well suited to future analysis of satellite soil moisture retrievals and finer-scale soil moisture models.

  2. Impact of land management on soil structure and soil hydraulic properties

    NASA Astrophysics Data System (ADS)

    Kodesova, Radka; Jirku, Veronika; Nikodem, Antonin; Muhlhanselova, Marcela; Zigova, Anna

    2010-05-01

    Study is focused on a comparison of a soil structure and soil hydraulic properties within soil profiles of a same soil type under different land management. Study was performed in Haplic Luvisol in Hnevceves the Czech Republic. Two soil profiles, which were in close distance from each other, were chosen: 1. under the conventional tillage, 2. under the permanent (30 years) grass cover. Soil sampling and field experiments were carried out immediately after the harvest of winter barley in 2008. The micromorphological images were used to evaluate the soil structure of all Ap, Bt1, Bt2 and C diagnostic horizons. The hydraulic properties of the diagnostic horizons were studied in the laboratory using multistep outflow experiments performed on the undisturbed 100-cm3 soil samples. A tension disc infiltrometer (with a disc radius of 10 cm) and minidisc tension infiltrometers (with a disc radius of 2.2 cm) were used to measure cumulative water infiltration under unsaturated conditions created using a pressure head of -2 cm. Measurements were performed at a depths of 5, 45, 75 and 110 cm, which corresponded to the Ap, Bt1, Bt2 and C horizons of studied Haplic Luvisol at both locations. The Guelph permeameter was used to measure cumulative water flux under surface ponding conditions. The depth of the drilled well was 10, 50, 80 and 115 cm, the well radius was 3 cm, and the well ponding depth was 5 cm. Both tests were used to evaluate hydraulic conductivity (K for h=-2cm, and Ks) values. Results showed, that while properties in the Bt2 and C horizons of both soil profiles were relatively similar, properties in the Ap and Bt1 horizons were different. The fraction of gravitational pores (which may cause preferential flow) in the Ap and Bt1 horizons of the soil profile under the convectional tillage was large than those in the Ap and Bt1 horizons of the soil profile under the permanent grass. This influenced for instance the Ks values measured using the Guelph permeametr. The Ks

  3. Distribution of rock fragments and their effects on hillslope soil erosion in purple soil, China

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyan

    2017-04-01

    Purple soil is widely distributed in Sichuan Basin and Three Gorges Reservoir Area. Purple soil region is abundant in soil fertility and hydrothermal resources, playing an important role in the agricultural development of China. Soil erosion has long been recognized as a major environmental problem in the purple soil region where the population is large and slope farming is commonly practiced, and rainstorm is numerous. The existence of rock fragments is one of the most important characteristics of purple soil. Rock fragments at the soil surface or in the soil layer affect soil erosion processes by water in various direct and indirect ways, thus the erosion processes of soil containing rock fragments have unique features. Against the severe soil degradation by erosion of purple soil slope, carrying out the research about the characteristics of purple soil containing rock fragments and understanding the influence of rock fragments on soil erosion processes have important significance, which would promote the rational utilization of purple soil slope land resources and accurate prediction of purple soil loss. Therefore, the aims of this study were to investigate the distribution of rock fragments in purple soil slope and the impact of rock fragment content on soil physical properties and soil erosion. First, field sampling methods were used to survey the spatial variability of rock fragments in soil profiles and along slope and the physical properties of soils containing rock fragments. Secondly, indoor simulated rainfall experiments were used to exam the effect of rock fragments in the soil layer on soil erosion processes and the relationships between rainfall infiltration, change of surface flow velocity, surface runoff volume and sediment on one hand, and rock fragment content (Rv, 0% 30%, which was determined according the results of field investigation for rock fragment distribution) on the other were investigated. Thirdly, systematic analysis about the

  4. Large-extent digital soil mapping approaches for total soil depth

    NASA Astrophysics Data System (ADS)

    Mulder, Titia; Lacoste, Marine; Saby, Nicolas P. A.; Arrouays, Dominique

    2015-04-01

    Total soil depth (SDt) plays a key role in supporting various ecosystem services and properties, including plant growth, water availability and carbon stocks. Therefore, predictive mapping of SDt has been included as one of the deliverables within the GlobalSoilMap project. In this work SDt was predicted for France following the directions of GlobalSoilMap, which requires modelling at 90m resolution. This first method, further referred to as DM, consisted of modelling the deterministic trend in SDt using data mining, followed by a bias correction and ordinary kriging of the residuals. Considering the total surface area of France, being about 540K km2, employed methods may need to be able dealing with large data sets. Therefore, a second method, multi-resolution kriging (MrK) for large datasets, was implemented. This method consisted of modelling the deterministic trend by a linear model, followed by interpolation of the residuals. For the two methods, the general trend was assumed to be explained by the biotic and abiotic environmental conditions, as described by the Soil-Landscape paradigm. The mapping accuracy was evaluated by an internal validation and its concordance with previous soil maps. In addition, the prediction interval for DM and the confidence interval for MrK were determined. Finally, the opportunities and limitations of both approaches were evaluated. The results showed consistency in mapped spatial patterns and a good prediction of the mean values. DM was better capable in predicting extreme values due to the bias correction. Also, DM was more powerful in capturing the deterministic trend than the linear model of the MrK approach. However, MrK was found to be more straightforward and flexible in delivering spatial explicit uncertainty measures. The validation indicated that DM was more accurate than MrK. Improvements for DM may be expected by predicting soil depth classes. MrK shows potential for modelling beyond the country level, at high

  5. Cultural Patterns of Soil Understanding

    NASA Astrophysics Data System (ADS)

    Patzel, Nikola; Feller, Christian

    2017-04-01

    Living soil supports all terrestrial ecosystems. The only global threat to earth's soils comes from human societies' land use and resource consuming activities. Soil perception and understanding by soil scientists are mainly drawn from biophysical parameters and found within Cartesian rationality, and not, or much less consciously from its rather intangible cultural dimension. But nevertheless, human soil perception, soil awareness, and soil relation are a cultural phenomenon, too. Aiming at soil awareness and education, it is of first order importance for the soil science community and the IUSS to study, discuss and communicate also about the cultural perceptions and representations of soil. For any society, cultural patterns in their relation to soil encompass: (i) General culturally underlying structures like (religious or 'secular') myths and belief systems. (ii) The personal, individual relation to/with and behaviour towards soil. This includes implicit concepts of soil being part integral concepts of landscape because the large majority of humans don't see soil as a distinct object. This communication would be to make evident: (i) the importance of cultural patterns and psychic/psychological background concerning soil, by case studies and overviews on different cultural areas, (ii) the necessity to develop reflections on this topic as well to communicate about soil with large public, as to raise awareness soil scientists to the cultural dimension of soils. A working group was recently founded at IUSS (Division 4) on this topic.

  6. Degradation and resilience of soils

    PubMed Central

    Lal, R.

    1997-01-01

    Debate on global soil degradation, its extent and agronomic impact, can only be resolved through understanding of the processes and factors leading to establishment of the cause-effect relationships for major soils, ecoregions, and land uses. Systematic evaluation through long-term experimentation is needed for establishing quantitative criteria of (i) soil quality in relation to specific functions; (ii) soil degradation in relation to critical limits of key soil properties and processes; and (iii) soil resilience in relation to the ease of restoration through judicious management and discriminate use of essential input. Quantitative assessment of soil degradation can be obtained by evaluating its impact on productivity for different land uses and management systems. Interdisciplinary research is needed to quantify soil degradation effects on decrease in productivity, reduction in biomass, and decline in environment quality throught pollution and eutrophication of natural waters and emission of radiatively-active gases from terrestrial ecosystems to the atmosphere. Data from long-term field experiments in principal ecoregions are specifically needed to (i) establish relationships between soil quality versus soil degradation and soil quality versus soil resilience; (ii) identify indicators of soil quality and soil resilience; and (iii) establish critical limits of important properties for soil degradation and soil resilience. There is a need to develop and standardize techniques for measuring soil resilience.

  7. Indicators: Soil Chemistry

    EPA Pesticide Factsheets

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  8. SOIL METAL BIOAVAILABILITY

    EPA Science Inventory

    Reducing risks associated with metals in soil has typically been accomplished by soil removal, covering, or dilution by mixing with uncontaminated soil. However, as our understanding of bioavailability and the relationship between metal form and bioavailability increases we are ...

  9. Soil-geographical regionalization as a basis for digital soil mapping: Karelia case study

    NASA Astrophysics Data System (ADS)

    Krasilnikov, P.; Sidorova, V.; Dubrovina, I.

    2010-12-01

    Recent development of digital soil mapping (DSM) allowed improving significantly the quality of soil maps. We tried to make a set of empirical models for the territory of Karelia, a republic at the North-East of the European territory of Russian Federation. This territory was selected for the pilot study for DSM for two reasons. First, the soils of the region are mainly monogenetic; thus, the effect of paleogeographic environment on recent soils is reduced. Second, the territory was poorly mapped because of low agricultural development: only 1.8% of the total area of the republic is used for agriculture and has large-scale soil maps. The rest of the territory has only small-scale soil maps, compiled basing on the general geographic concepts rather than on field surveys. Thus, the only solution for soil inventory was the predictive digital mapping. The absence of large-scaled soil maps did not allow data mining from previous soil surveys, and only empirical models could be applied. For regionalization purposes, we accepted the division into Northern and Southern Karelia, proposed in the general scheme of soil regionalization of Russia; boundaries between the regions were somewhat modified. Within each region, we specified from 15 (Northern Karelia) to 32 (Southern Karelia) individual soilscapes and proposed soil-topographic and soil-lithological relationships for every soilscape. Further field verification is needed to adjust the models.

  10. Soil organic matter stabilization in grazing highland soils from the Andean Plateau

    NASA Astrophysics Data System (ADS)

    Muñoz, M. A.; Faz, A.; Zornoza, R.

    2012-04-01

    Grasslands comprise approximately 40% of the earth's land area and play a critical role in the global carbon cycle. Apolobamba is a grazing highland located in the Andean Plateau where sustainable vicuna (Vicugna vicugna) management programme is carried out. Understanding the soil properties and the organic matter dynamics is fundamental to determine the grazing impacts in the carbon reservoirs. However, the labile and recalcitrant fractions of C have not been widely studied under field conditions, especially in high grasslands. The objectives of this survey were to: (i) achieve a soil characterization through general physico-chemical properties and (ii) study soil organic matter stabilization through recalcitrant and labile carbon budgets in Apolobamba. Regarding the lastly vicuna censuses carried out in the studied area, eight representative zones with different vicuna densities were selected and soil samples were collected. Other characteristics were also considered to select the study zones: (1) alpaca densities, (2) vegetation communities (3) plant cover and (4) landscape and geo-morphological description. Recalcitrant and water soluble organic carbon were determined as well as recalcitrant index. General soil characterization showed strongly acid and no saline soils with high cation exchange capacity and sandy-loam and loam textures. Total nitrogen contents indicated no limitation for the native vegetation growth. In general, no relationships were found among general soil properties, vicuna and alpaca densities; however, zones with highest alpaca density could be prone to soil erosion based on the available P distribution and the texture results. Additionally, a negative alpaca grazing influence in the soil organic carbon stocks was observed. On the other hand, high soil recalcitrant carbon contents (3.7 ± 0.3 kg m-2) and recalcitrance index (0.8 ± 0.1) were found. Likewise, labile C exhibited similar values to those obtained from researchers conducted in

  11. Spatial disaggregation of complex soil map units at regional scale based on soil-landscape relationships

    NASA Astrophysics Data System (ADS)

    Vincent, Sébastien; Lemercier, Blandine; Berthier, Lionel; Walter, Christian

    2015-04-01

    Accurate soil information over large extent is essential to manage agronomical and environmental issues. Where it exists, information on soil is often sparse or available at coarser resolution than required. Typically, the spatial distribution of soil at regional scale is represented as a set of polygons defining soil map units (SMU), each one describing several soil types not spatially delineated, and a semantic database describing these objects. Delineation of soil types within SMU, ie spatial disaggregation of SMU allows improved soil information's accuracy using legacy data. The aim of this study was to predict soil types by spatial disaggregation of SMU through a decision tree approach, considering expert knowledge on soil-landscape relationships embedded in soil databases. The DSMART (Disaggregation and Harmonization of Soil Map Units Through resampled Classification Trees) algorithm developed by Odgers et al. (2014) was used. It requires soil information, environmental covariates, and calibration samples, to build then extrapolate decision trees. To assign a soil type to a particular spatial position, a weighed random allocation approach is applied: each soil type in the SMU is weighted according to its assumed proportion of occurrence in the SMU. Thus soil-landscape relationships are not considered in the current version of DSMART. Expert rules on soil distribution considering the relief, parent material and wetlands location were proposed to drive the procedure of allocation of soil type to sampled positions, in order to integrate the soil-landscape relationships. Semantic information about spatial organization of soil types within SMU and exhaustive landscape descriptors were used. In the eastern part of Brittany (NW France), 171 soil types were described; their relative area in the SMU were estimated, geomorphological and geological contexts were recorded. The model predicted 144 soil types. An external validation was performed by comparing predicted

  12. Assessing the dynamics of the upper soil layer relative to soil management practices

    NASA Astrophysics Data System (ADS)

    Hatfield, J.; Wacha, K.; Dold, C.

    2017-12-01

    The upper layer of the soil is the critical interface between the soil and the atmosphere and is the most dynamic in response to management practices. One of the soil properties most reflective to changes in management is the stability of the aggregates because this property controls infiltration of water and exchange of gases. An aggregation model has been developed based on the factors that control how aggregates form and the forces which degrade aggregates. One of the major factors for this model is the storage of carbon into the soil and the interaction with the soil biological component. To increase soil biology requires a stable microclimate that provides food, water, shelter, and oxygen which in turn facilitates the incorporation of organic material into forms that can be combined with soil particles to create stable aggregates. The processes that increase aggregate size and stability are directly linked the continual functioning of the biological component which in turn changes the physical and chemical properties of the soil. Soil aggregates begin to degrade as soon as there is no longer a supply of organic material into the soil. These processes can range from removal of organic material and excessive tillage. To increase aggregation of the upper soil layer requires a continual supply of organic material and the biological activity that incorporates organic material into substances that create a stable aggregate. Soils that exhibit stable soil aggregates at the surface have a prolonged infiltration rate with less runoff and a gas exchange that ensures adequate oxygen for maximum biological activity. Quantifying the dynamics of the soil surface layer provides a quantitative understanding of how management practices affect aggregate stability.

  13. Understanding Soil Moisture

    USDA-ARS?s Scientific Manuscript database

    Understanding soil moisture is critical for landscape irrigation management. This landscaep irrigation seminar will compare volumetric and matric potential soil-moisture sensors, discuss the relationship between their readings and demonstrate how to use these data. Soil water sensors attempt to sens...

  14. Can we predict uranium bioavailability based on soil parameters? Part 1: effect of soil parameters on soil solution uranium concentration.

    PubMed

    Vandenhove, H; Van Hees, M; Wouters, K; Wannijn, J

    2007-01-01

    Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for (238)U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K(d), L kg(-1)) and the organic matter content (R(2)=0.70) and amorphous Fe content (R(2)=0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH=6, log(K(d)) was linearly related with pH [log(K(d))=-1.18 pH+10.8, R(2)=0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex.

  15. On soil textural classifications and soil-texture-based estimations

    NASA Astrophysics Data System (ADS)

    Ángel Martín, Miguel; Pachepsky, Yakov A.; García-Gutiérrez, Carlos; Reyes, Miguel

    2018-02-01

    The soil texture representation with the standard textural fraction triplet sand-silt-clay is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide a better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from an entropy-based representation of the textural triplet with experimental data for 6240 soil samples. The results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the sand-silt-clay and very coarse+coarse + medium sand - fine + very fine sand - silt+clay were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application and data specific.

  16. Soil aggregation, erodibility, and erosion rates in mountain soils (NW Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Stanchi, S.; Falsone, G.; Bonifacio, E.

    2015-04-01

    Erosion is a relevant soil degradation factor in mountain agrosilvopastoral ecosystems that can be enhanced by the abandonment of agricultural land and pastures left to natural evolution. The on-site and off-site consequences of soil erosion at the catchment and landscape scale are particularly relevant and may affect settlements at the interface with mountain ecosystems. RUSLE (Revised Universal Soil Loss Equation) estimates of soil erosion consider, among others, the soil erodibility factor (K), which depends on properties involved in structure and aggregation. A relationship between soil erodibility and aggregation should therefore be expected. However, erosion may limit the development of soil structure; hence aggregates should not only be related to erodibility but also partially mirror soil erosion rates. The aim of the research was to evaluate the agreement between aggregate stability and erosion-related variables and to discuss the possible reasons for discrepancies in the two kinds of land use considered (forest and pasture). Topsoil horizons were sampled in a mountain catchment under two vegetation covers (pasture vs. forest) and analyzed for total organic carbon, total extractable carbon, pH, and texture. Soil erodibility was computed, RUSLE erosion rate was estimated, and aggregate stability was determined by wet sieving. Aggregation and RUSLE-related parameters for the two vegetation covers were investigated through statistical tests such as ANOVA, correlation, and regression. Soil erodibility was in agreement with the aggregate stability parameters; i.e., the most erodible soils in terms of K values also displayed weaker aggregation. Despite this general observation, when estimating K from aggregate losses the ANOVA conducted on the regression residuals showed land-use-dependent trends (negative average residuals for forest soils, positive for pastures). Therefore, soil aggregation seemed to mirror the actual topsoil conditions better than soil

  17. Historical climate controls soil respiration responses to current soil moisture.

    PubMed

    Hawkes, Christine V; Waring, Bonnie G; Rocca, Jennifer D; Kivlin, Stephanie N

    2017-06-13

    Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40-70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration-moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.

  18. Historical climate controls soil respiration responses to current soil moisture

    PubMed Central

    Waring, Bonnie G.; Rocca, Jennifer D.; Kivlin, Stephanie N.

    2017-01-01

    Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40–70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration–moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall. PMID:28559315

  19. On the structural factors of soil humic matter related to soil water repellence in fire-affected soils

    NASA Astrophysics Data System (ADS)

    Almendros, G.; González-Vila, F. J.; González-Pérez, J. A.; Knicker, H.; De la Rosa, J. M.; Dettweiler, C.; Hernández, Z.

    2012-04-01

    In order to elucidate the impact of forest fires on physical and chemical properties of the soils as well as on the chemical composition of the soil organic matter, samples from two Mediterranean soils with contrasted characteristics and vegetation (O horizon, Lithic Leptosols under Quercus ilex and Pinus pinaster) and one agricultural soil (Ap horizon, Luvisol) were heated at 350 °C in laboratory conditions for three successive steps up to 600 s. The C- and N-depletion in the course of the heating showed small changes up to an oxidation time of 300 s. On the other side, and after 600 s, considerable C-losses (between 21% in the Luvisol and 50% in the Leptosols) were observed. The relatively low N-depletion ca. 4% (Luvisol) and 21% (Leptosol under pine) suggested preferential loss of C and the subsequent relative enrichment of nitrogen. Paralleling the progressive depletion of organic matter, the Leptosols showed a significant increase of both pH and electrical conductivity. The former change paralleled the rapid loss of carboxyl groups, whereas the latter point to the relative enrichment of ash with a bearing on the concentration of inorganic ions, which could be considered a positive effect for the post-fire vegetation. The quantitative and qualitative analyses by solid-state 13C NMR spectra of the humic fractions in the samples subjected to successive heating times indicate significant concentration of aromatic structures newly-formed in the course of the dehydration and cyclization of carbohydrates (accumulation of black carbon-type polycyclic aromatic structures), and probably lipids and peptides. The early decarboxylation, in addition to the depletion of O-alkyl hydrophilic constituents and further accumulation of secondary aromatic structures resulted in the dramatic increase in the soil water drop penetration time. It was confirmed that this enhancement of the soil hydrophobicity is not related to an increased concentration of soil free lipid, but is

  20. Soil invertebrate fauna affect N2 O emissions from soil.

    PubMed

    Kuiper, Imke; de Deyn, Gerlinde B; Thakur, Madhav P; van Groenigen, Jan Willem

    2013-09-01

    Nitrous oxide (N2 O) emissions from soils contribute significantly to global warming. Mitigation of N2 O emissions is severely hampered by a lack of understanding of its main controls. Fluxes can only partly be predicted from soil abiotic factors and microbial analyses - a possible role for soil fauna has until now largely been overlooked. We studied the effect of six groups of soil invertebrate fauna and tested the hypothesis that all of them increase N2 O emissions, although to different extents. We conducted three microcosm experiments with sandy soil and hay residue. Faunal groups included in our experiments were as follows: fungal-feeding nematodes, mites, springtails, potworms, earthworms and isopods. In experiment I, involving all six faunal groups, N2 O emissions declined with earthworms and potworms from 78.4 (control) to 37.0 (earthworms) or 53.5 (potworms) mg N2 O-N m(-2) . In experiment II, with a higher soil-to-hay ratio and mites, springtails and potworms as faunal treatments, N2 O emissions increased with potworms from 51.9 (control) to 123.5 mg N2 O-N m(-2) . Experiment III studied the effect of potworm density; we found that higher densities of potworms accelerated the peak of the N2 O emissions by 5 days (P < 0.001), but the cumulative N2 O emissions remained unaffected. We propose that increased soil aeration by the soil fauna reduced N2 O emissions in experiment I, whereas in experiment II N2 O emissions were driven by increased nitrogen and carbon availability. In experiment III, higher densities of potworms accelerated nitrogen and carbon availability and N2 O emissions, but did not increase them. Overall, our data show that soil fauna can suppress, increase, delay or accelerate N2 O emissions from soil and should therefore be an integral part of future N2 O studies. © 2013 John Wiley & Sons Ltd.