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Sample records for forest soil survey

  1. A metagenomic-based survey of microbial (de)halogenation potential in a German forest soil

    PubMed Central

    Weigold, Pascal; El-Hadidi, Mohamed; Ruecker, Alexander; Huson, Daniel H.; Scholten, Thomas; Jochmann, Maik; Kappler, Andreas; Behrens, Sebastian

    2016-01-01

    In soils halogens (fluorine, chlorine, bromine, iodine) are cycled through the transformation of inorganic halides into organohalogen compounds and vice versa. There is evidence that these reactions are microbially driven but the key enzymes and groups of microorganisms involved are largely unknown. Our aim was to uncover the diversity, abundance and distribution of genes encoding for halogenating and dehalogenating enzymes in a German forest soil by shotgun metagenomic sequencing. Metagenomic libraries of three soil horizons revealed the presence of genera known to be involved in halogenation and dehalogenation processes such as Bradyrhizobium or Pseudomonas. We detected a so far unknown diversity of genes encoding for (de)halogenating enzymes in the soil metagenome including specific and unspecific halogenases as well as metabolic and cometabolic dehalogenases. Genes for non-heme, no-metal chloroperoxidases and haloalkane dehalogenases were the most abundant halogenase and dehalogenase genes, respectively. The high diversity and abundance of (de)halogenating enzymes suggests a strong microbial contribution to natural halogen cycling. This was also confirmed in microcosm experiments in which we quantified the biotic formation of chloroform and bromoform. Knowledge on microorganisms and genes that catalyze (de)halogenation reactions is critical because they are highly relevant to industrial biotechnologies and bioremediation applications. PMID:27353292

  2. A metagenomic-based survey of microbial (de)halogenation potential in a German forest soil.

    PubMed

    Weigold, Pascal; El-Hadidi, Mohamed; Ruecker, Alexander; Huson, Daniel H; Scholten, Thomas; Jochmann, Maik; Kappler, Andreas; Behrens, Sebastian

    2016-01-01

    In soils halogens (fluorine, chlorine, bromine, iodine) are cycled through the transformation of inorganic halides into organohalogen compounds and vice versa. There is evidence that these reactions are microbially driven but the key enzymes and groups of microorganisms involved are largely unknown. Our aim was to uncover the diversity, abundance and distribution of genes encoding for halogenating and dehalogenating enzymes in a German forest soil by shotgun metagenomic sequencing. Metagenomic libraries of three soil horizons revealed the presence of genera known to be involved in halogenation and dehalogenation processes such as Bradyrhizobium or Pseudomonas. We detected a so far unknown diversity of genes encoding for (de)halogenating enzymes in the soil metagenome including specific and unspecific halogenases as well as metabolic and cometabolic dehalogenases. Genes for non-heme, no-metal chloroperoxidases and haloalkane dehalogenases were the most abundant halogenase and dehalogenase genes, respectively. The high diversity and abundance of (de)halogenating enzymes suggests a strong microbial contribution to natural halogen cycling. This was also confirmed in microcosm experiments in which we quantified the biotic formation of chloroform and bromoform. Knowledge on microorganisms and genes that catalyze (de)halogenation reactions is critical because they are highly relevant to industrial biotechnologies and bioremediation applications. PMID:27353292

  3. Carbon Sequestration in Forest Soils

    NASA Astrophysics Data System (ADS)

    Lal, R.

    2006-05-01

    Carbon (C) sequestration in soils and forests is an important strategy of reducing the net increase in atmospheric CO2 concentration by fossil fuel combustion, deforestation, biomass burning, soil cultivation and accelerated erosion. Further, the so-called "missing or fugitive CO2" is also probably being absorbed in a terrestrial sink. Three of the 15 strategies proposed to stabilize atmospheric CO2 concentrations by 2054, with each one to sequester 1 Pg Cyr-1, include: (i) biofuel plantations for bioethanol production, (ii) reforestation, afforestation and establishment of new plantations, and (iii) conversion of plow tillage to no-till farming. Enhancing soil organic carbon (SOC) pool is an important component in each of these three options, but especially so in conversion of degraded/marginal agricultural soils to short rotation woody perennials, and establishment of plantations for biofuel, fiber and timber production. Depending upon the prior SOC loss because of the historic land used and management-induced soil degradation, the rate of soil C sequestration in forest soils may be 0 to 3 Mg C ha-1 yr-1. Tropical forest ecosystems cover 1.8 billion hectares and have a SOC sequestration potential of 200 to 500 Tg C yr-1 over 59 years. However, increasing production of forest biomass may not always increase the SOC pool. Factors limiting the rate of SOC sequestration include C: N ratio, soil availability of N and other essential nutrients, concentration of recalcitrant macro-molecules (e.g., lignin, suberin), soil properties (e.g., clay content and mineralogy, aggregation), soil drainage, and climate (mean annual precipitation and temperature). The SOC pool can be enhanced by adopting recommended methods of forest harvesting and site preparation to minimize the "Covington effect," improving soil drainage, alleviating soil compaction, growing species with a high NPP, and improving soil fertility including the availability of micro-nutrients. Soil fertility

  4. Comparison of tropical forest surveys

    SciTech Connect

    Molofsky, J.; Hall, C.A.S.; Myers, N.

    1986-06-01

    This report examines the two most recent studies of tropical forest areas and rates of forest loss: Norman Myers' conversion of Tropical Moist Forests (1980), and the FAO/UNEP Tropical Forest Resources Assessment Project in order to identify and clarify discrepancies between them. The apparent discrepancy between their respective estimates of deforestation rates has been the basis of a continuing controversy. Myers' report was concerned principally with the conversion of virgin forests to other land use and the resulting extinction of tropical species. The FAO/UNEP report emphasized the availability of forest resources to meet the future fuelwood, housing, and economic needs of UN member states. The present paper attempts to identify more precisely the differences between the two studies in order to integrate the large tropical forest data base from these two sources into a cohesive whole. Specifically, we identify those countries covered in both surveys where the largest differences occur. Our study was not designed to assess all discrepancies between Myers and FAO but only the discrepancies for those countries where both investigators have given specific numbers.

  5. Role of forest soils in the national greenhouse gas inventory

    NASA Astrophysics Data System (ADS)

    Jandl, R.

    2012-12-01

    In Austria the forests are a key category of the GHG budget. The role of forest soils as a sink or source of carbon has so far not been fully assessed and as a default position a stable soil carbon pool was reported. A combination from a modeling exercise and a field survey allowed the scrutinization of this assumption. The field data represent a repeated soil inventory after 20 years. Due to the spatial heterogeneity of chemical soil properties no clear conclusion of the temporal change of soil carbon was made. The data set from the field survey was used for the validation of a modeling exercise. We used the model Yasso07 that is well suited for the available site information in Austria. The measured and the simulated soil carbon change had an acceptable fit. The modeling exercise suggested a statistically insignificant loss of soil carbon during a committment period of the Kyoto Protocol. The standing biomass of the forest is still a carbon sink. Owing to the large forest area this insignificant soil carbon loss strongly reduces the carbon sink strength of the entire forest.

  6. SOIL SURVEY GEOGRAPHIC DATABASE (SSURGO)

    EPA Science Inventory

    This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a 7.5 minute quadrangle ...

  7. 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

  8. Soil-calcium depletion linked to acid rain and forest growth in the eastern United States

    USGS Publications Warehouse

    Lawrence, Gregory B.; Huntington, T.G.

    1999-01-01

    Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) calcium in forest soils has decreased at locations in the northeastern and southeastern U.S., and (2) acid rain and forest growth (uptake of calcium from the soil by roots) are both factors contributing to calcium depletion.

  9. Critical Analysis of Forest Degradation in the Southern Eastern Ghats of India: Comparison of Satellite Imagery and Soil Quality Index

    PubMed Central

    Ramachandran, Andimuthu; Radhapriya, Parthasarathy; Jayakumar, Shanmuganathan; Dhanya, Praveen; Geetha, Rajadurai

    2016-01-01

    India has one of the largest assemblages of tropical biodiversity, with its unique floristic composition of endemic species. However, current forest cover assessment is performed via satellite-based forest surveys, which have many limitations. The present study, which was performed in the Eastern Ghats, analysed the satellite-based inventory provided by forest surveys and inferred from the results that this process no longer provides adequate information for quantifying forest degradation in an empirical manner. The study analysed 21 soil properties and generated a forest soil quality index of the Eastern Ghats, using principal component analysis. Using matrix modules and geospatial technology, we compared the forest degradation status calculated from satellite-based forest surveys with the degradation status calculated from the forest soil quality index. The Forest Survey of India classified about 1.8% of the Eastern Ghats’ total area as degraded forests and the remainder (98.2%) as open, dense, and very dense forests, whereas the soil quality index results found that about 42.4% of the total area is degraded, with the remainder (57.6%) being non-degraded. Our ground truth verification analyses indicate that the forest soil quality index along with the forest cover density data from the Forest Survey of India are ideal tools for evaluating forest degradation. PMID:26812397

  10. Critical Analysis of Forest Degradation in the Southern Eastern Ghats of India: Comparison of Satellite Imagery and Soil Quality Index.

    PubMed

    Ramachandran, Andimuthu; Radhapriya, Parthasarathy; Jayakumar, Shanmuganathan; Dhanya, Praveen; Geetha, Rajadurai

    2016-01-01

    India has one of the largest assemblages of tropical biodiversity, with its unique floristic composition of endemic species. However, current forest cover assessment is performed via satellite-based forest surveys, which have many limitations. The present study, which was performed in the Eastern Ghats, analysed the satellite-based inventory provided by forest surveys and inferred from the results that this process no longer provides adequate information for quantifying forest degradation in an empirical manner. The study analysed 21 soil properties and generated a forest soil quality index of the Eastern Ghats, using principal component analysis. Using matrix modules and geospatial technology, we compared the forest degradation status calculated from satellite-based forest surveys with the degradation status calculated from the forest soil quality index. The Forest Survey of India classified about 1.8% of the Eastern Ghats' total area as degraded forests and the remainder (98.2%) as open, dense, and very dense forests, whereas the soil quality index results found that about 42.4% of the total area is degraded, with the remainder (57.6%) being non-degraded. Our ground truth verification analyses indicate that the forest soil quality index along with the forest cover density data from the Forest Survey of India are ideal tools for evaluating forest degradation. PMID:26812397

  11. Regulation of nitrification in upland forest soils

    SciTech Connect

    Donaldson, J.M.

    1987-01-01

    Forest soils often have low nitrate levels and are slow to produce NO/sub 3//sup -/-N when incubated in the laboratory or after site disturbance. Several hypotheses have been proposed to explain the patterns of nitrification that have been observed in forests ecosystems. These hypotheses suggest that nitrification is limited by low soil pH, NH/sub 4//sup +/-N availability, the presence of allelopathic inhibitors or low levels of other nutrients, such as phosphorus. In this study, experiments were designed to determine if nitrate production in forest soils is regulated by soil pH, NH/sub 4//sup +/ of allelopathic compounds. Three sites representing secondary succession in upland oak-hickory forests were sampled five times during a one-year period. Sampling dates coincided with important stages in the phenological development of the site vegetation. Soils were incubated for up to six weeks in the laboratory. This allowed accurate definition of the potential for nitrogen mineralization and nitrification. Results of laboratory incubation and field-treatment experiments indicate that HN/sub 4//sup +/-N availability is the main factor regulating NH/sub 4//sup +/-oxidizer populations and nitrification in the forest soils investigated. Ammonium is the substrate of nitrification.

  12. Soil moisture in sessile oak forest gaps

    NASA Astrophysics Data System (ADS)

    Zagyvainé Kiss, Katalin Anita; Vastag, Viktor; Gribovszki, Zoltán; Kalicz, Péter

    2015-04-01

    By social demands are being promoted the aspects of the natural forest management. In forestry the concept of continuous forest has been an accepted principle also in Hungary since the last decades. The first step from even-aged stand to continuous forest can be the forest regeneration based on gap cutting, so small openings are formed in a forest due to forestry interventions. This new stand structure modifies the hydrological conditions for the regrowth. Without canopy and due to the decreasing amounts of forest litter the interception is less significant so higher amount of precipitation reaching the soil. This research focuses on soil moisture patterns caused by gaps. The spatio-temporal variability of soil water content is measured in gaps and in surrounding sessile oak (Quercus petraea) forest stand. Soil moisture was determined with manual soil moisture meter which use Time-Domain Reflectometry (TDR) technology. The three different sizes gaps (G1: 10m, G2: 20m, G3: 30m) was opened next to Sopron on the Dalos Hill in Hungary. First, it was determined that there is difference in soil moisture between forest stand and gaps. Second, it was defined that how the gap size influences the soil moisture content. To explore the short term variability of soil moisture, two 24-hour (in growing season) and a 48-hour (in dormant season) field campaign were also performed in case of the medium-sized G2 gap along two/four transects. Subdaily changes of soil moisture were performed. The measured soil moisture pattern was compared with the radiation pattern. It was found that the non-illuminated areas were wetter and in the dormant season the subdaily changes cease. According to our measurements, in the gap there is more available water than under the forest stand due to the less evaporation and interception loss. Acknowledgements: The research was supported by TÁMOP-4.2.2.A-11/1/KONV-2012-0004 and AGRARKLIMA.2 VKSZ_12-1-2013-0034.

  13. The variations of aluminium species in mountainous forest soils and its implications to soil acidification.

    PubMed

    Bradová, Monika; Tejnecký, Václav; Borůvka, Luboš; Němeček, Karel; Ash, Christopher; Šebek, Ondřej; Svoboda, Miroslav; Zenáhlíková, Jitka; Drábek, Ondřej

    2015-11-01

    Aluminium (Al) speciation is a characteristic that can be used as a tool for describing the soil acidification process. The question that was answered is how tree species (beech vs spruce) and type of soil horizon affect Al speciation. Our hypotesis is that spruce and beech forest vegetation are able to modify the chemical characteristics of organic horizon, hence the content of Al species. Moreover, these characteristics are seasonally dependent. To answer these questions, a detailed chromatographic speciation of Al in forest soils under contrasting tree species was performed. The Jizera Mountains area (Czech Republic) was chosen as a representative mountainous soil ecosystem. A basic forestry survey was performed on the investigated area. Soil and precipitation samples (throughfall, stemflow) were collected under both beech and spruce stands at monthly intervals from April to November during the years 2008-2011. Total aluminium content and Al speciation, pH, and dissolved organic carbon were determined in aqueous soil extracts and in precipitation samples. We found that the most important factors affecting the chemistry of soils, hence content of the Al species, are soil horizons and vegetation cover. pH strongly affects the amount of Al species under both forests. Fermentation (F) and humified (H) organic horizons contain a higher content of water extractable Al and Al(3+) compared to organo-mineral (A) and mineral horizons (B). With increasing soil profile depth, the amount of water extractable Al, Al(3+) and moisture decreases. The prevailing water-extractable species of Al in all studied soils and profiles under both spruce and beech forests were organically bound monovalent Al species. Distinct seasonal variations in organic and mineral soil horizons were found under both spruce and beech forests. Maximum concentrations of water-extractable Al and Al(3+) were determined in the summer, and the lowest in spring. PMID:26084557

  14. FOREST SOIL INFORMATION FOR ENVIRONMENTAL ASSESSMENT IN THE WESTERN OREGON CASCADES BASED ON LANDTYPE MAPPING

    EPA Science Inventory

    Forest health monitoring and other environmental assessments require information on the spatial distribution of basic soil physical and chemical properties. Traditional soil surveys are not available for large areas of forestland in the western US but there are some soil resour...

  15. [Electron microscopic study of forest soil].

    PubMed

    Kilbertus, G; Proth, J

    1979-08-01

    Scanning electron microscopy was used to evidence the aggregated structure of a forest soil as well as the presence of fungal hyphae external to soil aggregates. The supernatant of soil suspension in water mainly contained isolated bacteria, while ultrathin sections of aggregates frequently revealed groups of bacteria surrounded by a sheath of mucilage with adhering clay minerals on the outside. These results confirm the existence of two particular biotopes in the soil studied: one is located inside aggregates, and the other, in the inter-aggregate spaces. PMID:526892

  16. 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…

  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, J.; 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. ?? 2006 Institute of Botany, Chinese Academy of

  18. Mercury isotope compositions in North American forest soils and litters

    NASA Astrophysics Data System (ADS)

    Zheng, W.; Obrist, D.; Bergquist, B. A.

    2013-12-01

    Soils represent one of the largest reservoirs of mercury on Earth, playing a critical role in the natural cycle of mercury by acting as both a sink and source. However, it is not well understood how soils sequestrate and remobilize Hg. Natural variations in stable Hg isotopes are being explored as a promising tool in studying the transformation and transport of Hg. However, Hg isotopic data in soils is scarce. In addition, the limited isotopic data that exists is significantly different from those of atmospheric Hg, which is one of the major sources of Hg to soils. For example, Hg mass independent fractionation (MIF, typically reported as Δ199Hg) is positive in atmospheric wet deposition, but most soils display negative Δ199Hg. MIF on 200Hg (Δ200Hg) is also observed in atmospheric wet deposition, but not in soils. The discrepancy between soils and atmospheric samples is still unexplained. In this study, we surveyed the Hg isotope compositions in soil profiles, litters and fresh vegetation from four different forest sites across United States (Thompson forest, WA, Truckee, CA, Niwot Ridge, CO and Howland, MA). The current results from the WA site show that soils primarily display negative mass dependent fractionation for the even isotopes (MDF, reported as δ202Hg) with values for δ202Hg of up to -2.0‰. Significant MIF for both odd isotopes is also observed in all WA soil samples and Δ199Hg is mostly negative (up to -0.4‰). No MIF on 200Hg is observed in these soils. The negative Δ199Hg in soils is inconsistent with the positive Δ199Hg reported in atmospheric wet deposition, suggesting that either Hg transformations within or on the surface of soils and/or plants alter its isotope composition after deposition or other types of Hg deposition (e.g., Hg(0) or Hg(II) dry deposition) is more predominant. The Δ199Hg/Δ201Hg ratio is close to 1 in the soils, which is consistent with the results of laboratory photochemical reduction of inorganic Hg

  19. Four endoparasitic nematode destroying fungi isolated from sand ridge state forest soil.

    PubMed

    Monoson, H L; Conway, T D; Nelson, R E

    1975-12-01

    A survey to determine the endoparasitic nematode destroying fungi located within Sand Ridge State Forest of Illinois was conducted from 1 January to 3 April 1973. A total of seven nematode destroying fungal species were isolated from the collected soil samples. Harposporium helicoides, H. crassum, H. lilliputanum are endoparasitic nematophagous fungi that have been isolated previously from the forest soil. Acrostalagmus gonoides, A. obovatus, Cephalosporium balanoides, and Monacrosporium cionopagum are nematophagous fungal species that had not been isolated previously from Illinois soil. Soil pH's and soil nutrient levels were not important in the isolation frequency of the collected endoparasitic nematode destroying fungi. PMID:1239663

  20. Comparison of soil and forest floor properties of floodplain and surrounding forests in Igneada, Turkey.

    PubMed

    Tecimen, Huseyin Baris; Kavgaci, Ali

    2010-01-01

    In this study some soil and forest floor characteristics of floodplain forest, thermophile forest and sand dune were investigated at Igneada, Turkey. In this context, surface soil samples were analyzed and compared to each other in the extension of soil physical, chemical properties and as plant nutrition environment. To investigate the soil characteristics soil samples were collected from 48 sampling point. The distribution of the soils revealed that remarkably physical soil properties figure the ordination of soils in principal component analysis (PCA). We concluded that floodplain forests have quite different soil properties from the thermophile forest and sand dunes under the continuous effect of surrounding thermophile forest land with less sandy proportion to soil texture 52.4 at floodplain forest, 64.0% at thermophile forest and 91.0% at sand dunes and highly organic carbon 5.619, 4.191 and 0.478% respectively at 0-5 cm depth and total nitrogen content 0.213, 0.078 and 0.056% for floodplain forest > thermophile forest > sand dune soils, respectively. Weight and organic matter contents of forest floor were significantly higher in the thermophile forests. PMID:20648824

  1. Soil production in forested landscapes (Invited)

    NASA Astrophysics Data System (ADS)

    Roering, J. J.; Booth, A. M.

    2009-12-01

    One of the most fundamental characteristics that defines landscapes is the presence or absence of a soil mantle. In actively eroding terrain, soil (and other natural resources that depend on it) persists only when the rate of soil production is not eclipsed by denudation. Despite successful efforts to empirically estimate long-term rates of soil production, little predictive capability exists as soil formation results from a complex interplay of biological, physical, and chemical processes. Here, we synthesize a suite of observations from the steep, forested Oregon Coast Range (OCR) and anlayze the role of trees in the conversion of bedrock to soil. Pit/mound topography on forest floors attests to the persistent, wholesale overturning of soil by tree root activity. Using airborne LiDAR data for our study site in the western Oregon Coast Range, we calculated how terrain roughness varies with spatial scale. At scales greater than 10m, the well-established ridge/valley structure of the landscape defines the topography; whereas for scales less than 7m, terrain roughness increases rapidly reflecting the stochastic nature of bioturbation associated with large, coniferous trees. Empirical estimates of soil production in the OCR by Heimsath et al (2001, ESPL) reveal that production rates decrease exponentially with depth and the decay constant is 2.68 (1/m). From dozens of soil pits in the OCR, we show that the density of trees roots declines exponentially with depth at a similar rate, 2.57 (1/m). In other words, rates of soil production appear to be well-correlated with root density. Bedrock is often excavated during tree turnover events and we documented that the volume of bedrock incorporated in overturned coniferous rootwads increases rapidly for tree diameters greater than 0.5m (which correponds to a 60-80 yr old Douglas fir tree in Western Oregon). Smaller (and thus younger) trees entrain negligible bedrock when overturned, suggesting that their root systems are

  2. Investigation of soil carbon sequestration processes in a temperate deciduous forest using soil respiration experiments

    NASA Astrophysics Data System (ADS)

    Schütze, Claudia; Marañón-Jiménez, Sara; Zöphel, Hendrik; Gimper, Sebastian; Dienstbach, Laura; Garcia Quirós, Inmaculada; Cuntz, Matthias; Rebmann, Corinna

    2016-04-01

    Considering the carbon cycles of terrestrial ecosystems, soils represent a major long-term carbon storage pool. However, the storage capacity depends on several impact parameters based on biotic factors (e.g. vegetation activity, microbial activity, nutrient availability, interactions between vegetation and microbial activity) and abiotic driving factors (e.g. soil moisture, soil temperature, soil composition). Especially, increases in vegetation and microbial activity can lead to raised soil carbon release detectable as higher soil respiration rates. Within the frame of the ICOS project, several soil respiration experiments are under consideration at the temperate deciduous forest site "Hohes Holz" (Central Germany). These experiments started in May 2014. Soil respiration data acquisition was carried out using 8 automatic continuous chambers (LI-COR) and 60 different plots for bi-weekly survey chamber measurements in order to clarify the controlling factors for soil CO2 emissions such as litter availability, above- and belowground vegetation, and activation of microbial activity with temperature, soil moisture and root occurrence. Hence, several treatments (trenched, non-trenched, litter supply) were investigated on different plots within the research area. The data analysis of the 20-month observation period reveals preliminary results of the study. Obviously, significant differences between the trenched and the non-trenched plots concerning the CO2 emissions occurred. Increased soil carbon releases are supposed to be associated to the activation of microbial mineralization of soil organic matter by root inputs. Furthermore, depending on the amount of litter supply, different levels of activation were observed. The data of the continuous chamber measurements with a temporal resolution of one hour sampling interval can be used to show the dependence on above described biogeochemical processes due to abiotic controlling factors. Especially, soil moisture as a

  3. Forest Soil Respiration: Identifying Sources and Controls

    NASA Astrophysics Data System (ADS)

    Högberg, P.

    2008-12-01

    Most of the respiration in forests comes from the soil. This flux is composed of two components, autotrophic and heterotrophic respiration. In a strict sense the former should be plant belowground respiration only, but the term is used here to denote respiration by roots, their mycorrhizal fungal symbionts and other closely associated organisms dependent on recent photosynthate. Heterotrophs are organisms using organic matter, chiefly above- and belowground litters, as substrate (i.e. substrates of in general much higher ecosystem age). Because of the complexity of the plant-soil system, the component fluxes are difficult to study. I will discuss results of different approaches to partition soil respiratory components and to study their controls. The focus will be on northern boreal forests. In these generally strongly nitrogen-limited forests, the autotrophic respiration equals or exceeds the heterotrophic component. The large autotrophic component reflects high plant allocation of C to roots and mycorrhizal fungi in response to the low N supply. A physiological manipulation, girdling, which stops the flow of photosynthates to roots, showed that autotrophic respiration could account for as much as 70% in N-limited forests, but only 40% in fertilized forests. Also using girdling, we could show that a shift to lower summertime temperature leads to a decrease in heterotrophic but not in autotrophic activity, suggesting substrate (photosynthate) limitation of the latter. Physiological manipulations like girdling and trenching cannot be used to reveal the finer details of soil C dynamics. Natural abundance stable isotope (13C) and 14C approaches also have their limitations if a high resolution in terms of time, space and organism is required. A very high resolution can, of course, be obtained in studies of laboratory micro- or mesocosms, but the possibility to extend the interpretation of their results to the field may be questioned. In the CANIFLEX (CArbon NItrogen

  4. Priming effects in a subtropical forest soil

    NASA Astrophysics Data System (ADS)

    Li, Qianru; Sun, Yue; Xu, Xingliang

    2015-04-01

    Priming effects can accelerate decomposition of soil organic carbon (SOC) and thus have great potential to change SOC dynamics. Although temperature and addition of fresh substrates could affect the intensity and direction of priming, it remains unclear how their interactions affect priming. Therefore we conducted an incubation experiment using a subtropical forest soil. We incubated the soil for 10 days at two temperatures: 15oC and 25oC, with four treatments: CK (only adding water), G (13C-glucose addition), NT (13C-glucose and nitrate additions) and AM (13C-glucose and ammonium additions). The results showed that glucose addition significantly accelerated the decomposition of SOC in both temperatures, indicates that positive priming occurs in this subtropical soil. While negative priming was observed in soils with simultaneous additions of glucose and nitrogen addition, especially at 25oC. The effect of temperature on PE was not significant. This indicates that mining of nitrogen is a major mechanism responsible for priming in this subtropical soil and there is no strong interaction between temperature and substrate additions to induce priming.

  5. Forest soil carbon is threatened by intensive biomass harvesting

    NASA Astrophysics Data System (ADS)

    Achat, David L.; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

    2015-11-01

    Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers’ decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142-497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils.

  6. Forest soil carbon is threatened by intensive biomass harvesting

    PubMed Central

    Achat, David L.; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

    2015-01-01

    Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers’ decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142–497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils. PMID:26530409

  7. Forest soil carbon is threatened by intensive biomass harvesting.

    PubMed

    Achat, David L; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

    2015-01-01

    Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers' decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142-497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils. PMID:26530409

  8. Soil nitrogen gas emissions increase considerably in warmer forest soils

    NASA Astrophysics Data System (ADS)

    Kitzler, Barbara; Schindlbacher, Andreas; Jandl, Robert; Zechmeister-Boltenstern, Sophie

    2015-04-01

    Climate change will likely modify ecosystem properties and processes and therefore impact nitrogen (N) dynamics of forest soils. To elucidate the effect of warming and drought conditions on the nitrogen gas emissions we measured N2O and NO fluxes from the soil warming experiment Achenkirch, a spruce-fir-beech forest soil in the North Tyrolean limestone Alps in Austria. The uppermost layer of the soil was warmed (4°C) by heating cables during the snow-free seasons. Roofs were installed during 25 days in July/August 2008 and 2009 to simulate drought conditions. Gas sampling was conducted biweekly with static chambers (N2O). Gas concentrations were detected by GC. Nitric oxide fluxes were measured by an automatic dynamic chamber system on an hourly basis. In our study the emissions of N2O were increased by up to 73 % at warmed plots, and we observed a temporary increase following first rain. However N2O emissions of the drought affected plots remained depressed for more than two months after roof removal. Nitric oxide fluxes were increased considerably during dry periods and under warmer conditions.

  9. Organic carbon stocks and sequestration rates of forest soils in Germany.

    PubMed

    Grüneberg, Erik; Ziche, Daniel; Wellbrock, Nicole

    2014-08-01

    The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic layer C stock estimates were attributed to surveyed forest stands and CORINE land cover data. Mineral soil C stock estimates were linked with the distribution of dominant soil types according to the Soil Map of Germany (1 : 1 000 000) and subsequently related to the forest area. It appears that the C pool of the organic layer was largely depending on tree species and parent material, whereas the C pool of the mineral soil varied among soil groups. We identified the organic layer C pool as stable although C was significantly sequestered under coniferous forest at lowland sites. The mineral soils, however, sequestered 0.41 Mg C ha(-1) yr(-1) . Carbon pool changes were supposed to depend on stand age and forest transformation as well as an enhanced biomass input. Carbon stock changes were clearly attributed to parent material and soil groups as sandy soils sequestered higher amounts of C, whereas clayey and calcareous soils showed small gains and in some cases even losses of soil C. We further showed that the largest part of the overall sample variance was not explained by fine-earth stock variances, rather by the C concentrations variance. The applied uncertainty analyses in this study link the variability of strata with measurement errors. In accordance to other studies for Central Europe, the results showed that the applied method enabled a reliable nationwide quantification of the soil C pool development for a certain period. PMID:24616061

  10. Soil properties discriminating Araucaria forests with different disturbance levels.

    PubMed

    Bertini, Simone Cristina Braga; Azevedo, Lucas Carvalho Basilio; Stromberger, Mary E; Cardoso, Elke Jurandy Bran Nogueira

    2015-04-01

    Soil biological, chemical, and physical properties can be important for monitoring soil quality under one of the most spectacular vegetation formation on Atlantic Forest Biome, the Araucaria Forest. Our aim was to identify a set of soil variables capable of discriminating between disturbed, reforested, and native Araucaria forest soils such that these variables could be used to monitor forest recovery and maintenance. Soil samples were collected at dry and rainy season under the three forest types in two state parks at São Paulo State, Brazil. Soil biological, chemical, and physical properties were evaluated to verify their potential to differentiate the forest types, and discriminant analysis was performed to identify the variables that most contribute to the differentiation. Most of physical and chemical variables were sensitive to forest disturbance level, but few biological variables were significantly different when comparing native, reforested, and disturbed forests. Despite more than 20 years following reforestation, the reforested soils were chemically and biologically distinct from native and disturbed forest soils, mainly because of the greater acidity and Al3+ content of reforested soil. Disturbed soils, in contrast, were coarser in texture and contained greater concentrations of extractable P. Although biological properties are generally highly sensitive to disturbance and amelioration efforts, the most important soil variables to discriminate forest types in both seasons included Al3+, Mg2+, P, and sand, and only one microbial attribute: the NO2- oxidizers. Therefore, these five variables were the best candidates, of the variables we employed, for monitoring Araucaria forest disturbance and recovery. PMID:25792021

  11. Quantification of soil respiration in forest ecosystems across China

    NASA Astrophysics Data System (ADS)

    Song, Xinzhang; Peng, Changhui; Zhao, Zhengyong; Zhang, Zhiting; Guo, Baohua; Wang, Weifeng; Jiang, Hong; Zhu, Qiuan

    2014-09-01

    We collected 139 estimates of the annual forest soil CO2 flux and 173 estimates of the Q10 value (the temperature sensitivity) assembled from 90 published studies across Chinese forest ecosystems. We analyzed the annual soil respiration (Rs) rates and the temperature sensitivities of seven forest ecosystems, including evergreen broadleaf forests (EBF), deciduous broadleaf forests (DBF), broadleaf and needleleaf mixed forests (BNMF), evergreen needleleaf forests (ENF), deciduous needleleaf forests (DNF), bamboo forests (BF) and shrubs (SF). The results showed that the mean annual Rs rate was 33.65 t CO2 ha-1 year-1 across Chinese forest ecosystems. Rs rates were significantly different (P < 0.001) among the seven forest types, and were significantly and positively influenced by mean annual temperature (MAT), mean annual precipitation (MAP), and actual evapotranspiration (AET); but negatively affected by latitude and elevation. The mean Q10 value of 1.28 was lower than the world average (1.4-2.0). The Q10 values derived from the soil temperature at a depth of 5 cm varied among forest ecosystems by an average of 2.46 and significantly decreased with the MAT but increased with elevation and latitude. Moreover, our results suggested that an artificial neural network (ANN) model can effectively predict Rs across Chinese forest ecosystems. This study contributes to better understanding of Rs across Chinese forest ecosystems and their possible responses to global warming.

  12. Influences of soil acidity on Streptomyces populations inhabiting forest soils.

    PubMed Central

    Hagedorn, C

    1976-01-01

    The Streptomyces populations inhabiting five acidic forest soils were examined. It was found that lowering the pH of a medium selective for streptomycetes (starch-casein agar) to the pH of the particular soil horizon being plated influenced both the total numbers and types of streptomycetes that were isolated from the soils examined in this study. On the acidified medium both the numbers of streptomycetes and the percentage of total bacteria on the plates represented by streptomycetes increased (as compared with the same medium with a pH of 7.2). These differences were greatest on the isolations from the most acid soils. The largest concentrations of streptomycetes were found in the surface horizon (0 to 15 cm) and the litter layer immediately over the surface mineral horizon. Acidity tolerance tests demonstrated that random samplings of isolates contained acidophilic, neutrophilic, and acidoduric strains, with the largest numbers of acidophiles being found on the acidified media from the most acid soils. There were no differences between overall utilization of selected carbohydrates among the isolates taken from either the neutral or acidic media, although a larger proportion of the acid media isolates produced acid from the carbohydrates. Evidence is presented which indicates that different types of streptomycetes were isolated on the acid media, and possible reasons for the presence of these acid-tolerant populations are discussed. PMID:10835

  13. Soil acidification stimulates the emission of ethylene from temperate forest soils

    NASA Astrophysics Data System (ADS)

    Xu, Xingkai; Kazuyuki, Inubushi

    2009-11-01

    Soil acidification via acid precipitation is recognized to have detrimental impacts on forest ecosystems, which is in part associated with the function of ethylene released from the soil. However, the impacts of acidification on the cycling of ethylene in forest soils have not been fully taken into consideration in global change studies. Forest topsoils (0-5 cm) under four temperate forest stands were sampled to study the effects of a pH change on the emissions of ethylene and carbon dioxide from the soils and concentrations of dissolved organic carbon (DOC) released into the soils. Increasing acidification or alkalinization of forest soils could increase concentrations of DOC released into the soils under anoxic and oxic conditions. The ethylene emission from these forest topsoils could significantly increase with a decreasing pH, when the soils were acidified experimentally to a pH<4.0, and it increased with an increasing concentration of DOC released into the soils, which was different from the carbon dioxide emission from the soils. Hence, the short-term stimulating responses of ethylene emission to a decreasing pH in such forest soils resulted from the increase in the DOC concentration due to acidification rather than carbon mineralization. The results would promote one to study the effects of soil acidification on the cycling of ethylene under different forest stands, particularly under degraded forest stands with heavy acid depositions.

  14. [Effects of soil temperature and moisture on soil respiration in different forest types in Changbai Mountain].

    PubMed

    Wang, Miao; Ji, Lanzhu; Li, Qiurong; Liu, Yanqiu

    2003-08-01

    The effects of soil temperature (0, 5, 15, 25, 35 degrees C) and water content on soil respiration in three forest types in Changbai Mountain were evaluated in laboratory condition. The results indicated that the soil respiration rate was positively correlated to soil temperature from 0 to 35 degrees C and it increased with soil water content from 0.21 to 0.37 kg.kg-1. The soil respiration rate decreased with soil water content when water content was over the range. The result suggested the interactive effects of temperature and water content on soil respiration. There were significant differences in soil respiration among the various forest types and the highest was in broad leaf Korean pine forest, then in erman's birch forest, and it was the lowest in dark coniferous forest. The optimal condition for soil respiration in broad-leaved Korean pine forest was at 35 degrees C under 0.37 kg.kg-1 water content, and it was at 25 degrees C under 0.21 kg.kg-1 in dark coniferous forest and at 35 degrees C under 0.37 kg.kg-1 water content in erman's birch forest. Because the forests of broad leaf Korean pine, dark coniferous and erman's birch are located at various altitudes, the soil temperatures had 4-5 degrees C variation in different forest types during the same period. The soil respiration rates measured in brown pine mountain soil were lower than those in dark brown forest and they were higher in mountain grass forest soil than those in brown pine mountain soil. PMID:14655349

  15. Carbon stocks of dead wood, litter, and soil in the forest sector in Japan estimated by the National Forest Soil Carbon Inventory

    NASA Astrophysics Data System (ADS)

    Nanko, Kazuki; Ugawa, Shin; Takahashi, Masamichi; Morisada, Kazuhito; Takeuchi, Manabu; Matuura, Yojiro; Yoshinaga, Shuichiro; Araki, Makoto; Tanaka, Nagaharu; Ikeda, Shigeto; Miura, Satoru; Ishizuka, Shigehiro; Kobayashi, Masahiro; Inagaki, Masahiro; Imaya, Akihiro; Hashimoto, Shoji; Kaneko, Shinji

    2013-04-01

    The carbon (C) stocks of dead wood, litter, and soil are the basic data for evaluating the C sink function in the forest sector in Japan. We estimated the C stocks of dead wood, litter, and soil at 0-30 cm in the forest sector in Japan and clarified the spatial distribution of those C stocks according to region units. Data were collected in 2438 survey plots in FY 2006-2010 by the National Forest Soil Carbon Inventory Project, which surveyed the C stocks of dead wood, litter, and soil at 0-30 cm throughout the forest sector in Japan. The C stock (mean ± sample standard deviation) of dead wood, litter, and soil at 0-30 cm was 0.42 ± 0.67, 0.49 ± 0.32, and 6.94 ± 3.25 kg m-2, respectively. The C stock of soil at 0-30 cm was slightly lower than previous study in Japan. The difference might be attributed to the difference of the sampling methodologies. The C stocks of the three pools were significantly different among regions. Although temperature influenced the tendency in the distribution of the C stocks among regions of dead wood and litter, the tendency was not unidirectional. On the other hand, the C stock of soil at 0-30 cm was higher in northern Japan and lower in southern Japan, although high C stock was observed in some regions in the volcanic region of southern Japan. Thus, we suggest that the soil C stock at 0-30 cm is regulated by macro scale factors such as temperature as well as by the distribution of volcanic ash soils. The part of this study is published in Ugawa et al. (2012, Bull. FFPRI. 11, 207-221).

  16. Survey of invasive ants at Hakalau Forest National Wildlife Refuge

    USGS Publications Warehouse

    Peck, Robert W.; Banko, Paul C.

    2011-01-01

    We conducted a survey for invasive ants at Hakalau Forest National Wildlife Refuge, Hawai‘i Island, during 2009–2010 to evaluate potential threats to native arthropod communities and food webs. The focal area of the survey was the upper portion of the Hakalau Unit of the refuge, where native forest was being restored in abandoned cattle pastures. This area, between 1575 and 1940 m elevations, contained much alien kikuyu grass (Pennisetum clandestinum), but koa (Acacia koa) trees and other native species that were planted in the past 20 years were rapidly filling in the pasture. We surveyed for ants at predetermined points along roads, fences, and corridors of planted koa. Sampling methods primarily consisted of hand searching and pitfall traps, but bait cards were used additionally in some instances. Our results indicated that a single species, Cardiocondyla kagutsuchi, was widespread across the upper portion of the refuge. Cardiocondyla kagutsuchi seemed absent, or at least rare, in areas of tall, dense grass. Due to the undulating topography of the area, however, the dense grass cover was interspersed with outcroppings of exposed, gravelly soil. Presumably due to warming by the sun, many of the outcropped habitats supported colonies of C. kagutsuchi. We did not detect ants in the old-growth forest below the abandoned pastures, presumably because microhabitat conditions under the forest canopy were unsuitable. Although ecological impacts of C. kagutsuchi have not been reported, they may be limited by the small size of the ant, the relatively small size of colonies, and the apparent preference of the ant for disturbed areas that are dominated by alien species. Notably, our survey of Keanakolu-Mana Road between the Observatory Road (John A. Burns Way) and the town of Waimea detected a population of Argentine ants (Linepithema humile) approximately 5.1 km north of the Maulua Section of the refuge. We also surveyed for ants on the Kona Forest Unit of the refuge

  17. [Soil carbon cycle of Pinus tabulaeformis forest in Huoditang forest region of Qinling Mountains].

    PubMed

    Kang, Bowen; Liu, Jianjun; Dang, Kunliang; Chen, Haibin

    2006-05-01

    With soil carbon cycle compartment model,this paper studied the carbon storage and flux of each carbon compartment of soil under Pinus tabulaeformis, a main forest type in the Huoditang forest region of Qinling Mountain. The results showed that the storage of soil organic carbon was 146.071 t x hm(-2), with 130.366 t x hm(-2) in mineral soil layer and 12.626 t x hm(-2) in litter layer. The storage was lower than the average value of forest soils in China and of oak Sharptooth forest soil in Huoditang, but higher than that of the soils under temperate coniferous forest and tropical forest. The annual carbon input into litter layer was 5.939 t x hm(-2), with 56.9% from above-ground litter and 43.1% from underground dead roots, while that into mineral soil layer via humic acid was 2. 034 t x hm(-2). The annual amount of carbon released from the respiration of P. zabulaeformis forest-soil system was 14. 012 t x hm(-2), with litter layer, mineral soil layer, dead root system, and live root system occupied 15.7%, 14.5%, 11.7% and 58.1%, respectively. PMID:16883796

  18. 7 CFR 611.11 - Soil survey information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Soil survey information. 611.11 Section 611.11..., DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS SOIL SURVEYS Soil Survey Operations § 611.11 Soil survey information. (a) Availability. NRCS disseminates soil survey information to the public by any of the...

  19. 7 CFR 611.11 - Soil survey information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Soil survey information. 611.11 Section 611.11..., DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS SOIL SURVEYS Soil Survey Operations § 611.11 Soil survey information. (a) Availability. NRCS disseminates soil survey information to the public by any of the...

  20. 7 CFR 611.11 - Soil survey information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Soil survey information. 611.11 Section 611.11..., DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS SOIL SURVEYS Soil Survey Operations § 611.11 Soil survey information. (a) Availability. NRCS disseminates soil survey information to the public by any of the...

  1. 7 CFR 611.11 - Soil survey information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Soil survey information. 611.11 Section 611.11..., DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS SOIL SURVEYS Soil Survey Operations § 611.11 Soil survey information. (a) Availability. NRCS disseminates soil survey information to the public by any of the...

  2. 7 CFR 611.11 - Soil survey information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Soil survey information. 611.11 Section 611.11..., DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS SOIL SURVEYS Soil Survey Operations § 611.11 Soil survey information. (a) Availability. NRCS disseminates soil survey information to the public by any of the...

  3. Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

    PubMed

    Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

    2015-11-01

    Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests. PMID:25909978

  4. Development of soil hydraulic soil properties below ancient forest, planted forest and grassland

    NASA Astrophysics Data System (ADS)

    Archer, Nicole; Otten, Wilfred; Schmidt, Sonja; Bengough, Glyn; Bonell, Mike; Shah, Nadeem

    2014-05-01

    A number of serious flood events in recent years have focused attention on flood prevention and mitigation and modelling work suggests that climate change will lead to an increase in the intensity and frequency of flood events in many areas. To understand how soil hydraulic characteristics develops in relation to facilitating the infiltration and storage of storm rainfall, a hypothetical pedogensis sequence was first developed and then tested by investigating a grassland site and four Scots pine (Pinus sylvestris) forests of different ages in the Scottish Highlands. These sites are: grassland, six and 45 year-old Scots pine plantations, remnant 300 year old individual Scots pines and a 4000 year old Caledonian Forest. The soil characteristics measured were: field saturated hydraulic conductivity (Kfs) using a constant head well permeameter, root numbers and proportion were estimated from soil pits and soil cores were taken for three different soil depths (0.06 - 0.10, 0.16 - 0.20 and 0.26 to 0.40m) for laboratory measurements to estimate organic matter, soil water release curves, macro-pores, and X - ray tomography measured pore connectivity and soil pore structure. It was observed that cutting down of the plantation increased organic matter because of the increase of dead biomass and decreased pore connectivity, which resulted in reduced hydraulic conductivity during the early years of re-afforestation. Where older trees were left, after cutting and removing younger trees; the range of OM, hydraulic conductivity, pore connectivity, and macropores remained similar to and older Scots pine plantation (45 years old). The undisturbed Ancient Caledonian remnant forest (approximately 4000 years old) was observed to have remarkably heterogeneous soil characteristics, providing extreme values of Kfs (12 to 4992 mm hr-1), OM, and macropores. Such ranges of soil characteristics were considered to be the optimum to reduce local flooding, because the soil matrix could

  5. Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils.

    PubMed

    Magnago, Luiz F S; Martins, Sebastião V; Schaefer, Carlos E G R; Neri, Andreza V

    2012-09-01

    The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes. PMID:22886165

  6. Effects of Forest Gaps on Soil Properties in Castanopsis kawakamii Nature Forest.

    PubMed

    He, Zhongsheng; Liu, Jinfu; Su, Songjin; Zheng, Shiqun; Xu, Daowei; Wu, Zeyan; Hong, Wei; Wang, James Li-Ming

    2015-01-01

    The aim of this study is to analyze the effects of forest gaps on the variations of soil properties in Castanopsis kawakamii natural forest. Soil physical and chemical properties in various sizes and development stages were studied in C. kawakamii natural forest gaps. The results showed that forest gaps in various sizes and development stages could improve soil pore space structure and water characteristics, which may effectively promote the water absorbing capacity for plant root growth and play an important role in forest regeneration. Soil pore space structure and water characteristics in small gaps showed more obvious improvements, followed by the medium and large gaps. Soil pore space structure and water characteristics in the later development stage of forest gaps demonstrated more obvious improvements, followed by the early and medium development stages. The contents of hydrolysable N and available K in various sizes and development stages of forest gaps were higher than those of non-gaps, whereas the contents of total N, total P, available P, organic matter, and organic carbon were lower. The contents of total N, hydrolysable N, available K, organic matter, and organic carbon in medium gaps were higher than those of large and small gaps. The disturbance of forest gaps could improve the soils' physical and chemical properties and increase the population species' richness, which would provide an ecological basis for the species coexistence in C. kawakamii natural forest. PMID:26496710

  7. Biogeographic Distribution Patterns of Bacteria in Typical Chinese Forest Soils

    PubMed Central

    Xia, Zongwei; Bai, Edith; Wang, Qingkui; Gao, Decai; Zhou, Jidong; Jiang, Ping; Wu, Jiabing

    2016-01-01

    Microbes are widely distributed in soils and play a very important role in nutrient cycling and ecosystem services. To understand the biogeographic distribution of forest soil bacteria, we collected 115 soil samples in typical forest ecosystems across eastern China to investigate their bacterial community compositions using Illumina MiSeq high throughput sequencing based on 16S rRNA. We obtained 4,667,656 sequences totally and more than 70% of these sequences were classified into five dominant groups, i.e., Actinobacteria, Acidobacteria, Alphaproteobacteria, Verrucomicrobia, and Planctomycetes (relative abundance >5%). The bacterial diversity showed a parabola shape along latitude and the maximum diversity appeared at latitudes between 33.50°N and 40°N, an area characterized by warm-temperate zones and moderate temperature, neutral soil pH and high substrate availability (soil C and N) from dominant deciduous broad-leaved forests. Pairwise dissimilarity matrix in bacterial community composition showed that bacterial community structure had regional similarity and the latitude of 30°N could be used as the dividing line between southern and northern forest soils. Soil properties and climate conditions (MAT and MAP) greatly accounted for the differences in the soil bacterial structure. Among all soil parameters determined, soil pH predominantly affected the diversity and composition of the bacterial community, and soil pH = 5 probably could be used as a threshold below which soil bacterial diversity might decline and soil bacterial community structure might change significantly. Moreover, soil exchangeable cations, especially Ca2+ (ECa2+) and some other soil variables were also closely related to bacterial community structure. The selected environmental variables (21.11%) explained more of the bacterial community variation than geographic distance (15.88%), indicating that the edaphic properties and environmental factors played a more important role than geographic

  8. Biogeographic Distribution Patterns of Bacteria in Typical Chinese Forest Soils.

    PubMed

    Xia, Zongwei; Bai, Edith; Wang, Qingkui; Gao, Decai; Zhou, Jidong; Jiang, Ping; Wu, Jiabing

    2016-01-01

    Microbes are widely distributed in soils and play a very important role in nutrient cycling and ecosystem services. To understand the biogeographic distribution of forest soil bacteria, we collected 115 soil samples in typical forest ecosystems across eastern China to investigate their bacterial community compositions using Illumina MiSeq high throughput sequencing based on 16S rRNA. We obtained 4,667,656 sequences totally and more than 70% of these sequences were classified into five dominant groups, i.e., Actinobacteria, Acidobacteria, Alphaproteobacteria, Verrucomicrobia, and Planctomycetes (relative abundance >5%). The bacterial diversity showed a parabola shape along latitude and the maximum diversity appeared at latitudes between 33.50°N and 40°N, an area characterized by warm-temperate zones and moderate temperature, neutral soil pH and high substrate availability (soil C and N) from dominant deciduous broad-leaved forests. Pairwise dissimilarity matrix in bacterial community composition showed that bacterial community structure had regional similarity and the latitude of 30°N could be used as the dividing line between southern and northern forest soils. Soil properties and climate conditions (MAT and MAP) greatly accounted for the differences in the soil bacterial structure. Among all soil parameters determined, soil pH predominantly affected the diversity and composition of the bacterial community, and soil pH = 5 probably could be used as a threshold below which soil bacterial diversity might decline and soil bacterial community structure might change significantly. Moreover, soil exchangeable cations, especially Ca(2+) (ECa(2+)) and some other soil variables were also closely related to bacterial community structure. The selected environmental variables (21.11%) explained more of the bacterial community variation than geographic distance (15.88%), indicating that the edaphic properties and environmental factors played a more important role than

  9. Local climatic conditions constrain soil yeast diversity patterns in Mediterranean forests, woodlands and scrub biome.

    PubMed

    Yurkov, Andrey M; Röhl, Oliver; Pontes, Ana; Carvalho, Cláudia; Maldonado, Cristina; Sampaio, José Paulo

    2016-02-01

    Soil yeasts represent a poorly known fraction of the soil microbiome due to limited ecological surveys. Here, we provide the first comprehensive inventory of cultivable soil yeasts in a Mediterranean ecosystem, which is the leading biodiversity hotspot for vascular plants and vertebrates in Europe. We isolated and identified soil yeasts from forested sites of Serra da Arrábida Natural Park (Portugal), representing the Mediterranean forests, woodlands and scrub biome. Both cultivation experiments and the subsequent species richness estimations suggest the highest species richness values reported to date, resulting in a total of 57 and 80 yeast taxa, respectively. These values far exceed those reported for other forest soils in Europe. Furthermore, we assessed the response of yeast diversity to microclimatic environmental factors in biotopes composed of the same plant species but showing a gradual change from humid broadleaf forests to dry maquis. We observed that forest properties constrained by precipitation level had strong impact on yeast diversity and on community structure and lower precipitation resulted in an increased number of rare species and decreased evenness values. In conclusion, the structure of soil yeast communities mirrors the environmental factors that affect aboveground phytocenoses, aboveground biomass and plant projective cover. PMID:26568202

  10. Effects of Forest Gaps on Soil Properties in Castanopsis kawakamii Nature Forest

    PubMed Central

    He, Zhongsheng; Liu, Jinfu; Su, Songjin; Zheng, Shiqun; Xu, Daowei; Wu, Zeyan; Hong, Wei; Wang, James Li-Ming

    2015-01-01

    The aim of this study is to analyze the effects of forest gaps on the variations of soil properties in Castanopsis kawakamii natural forest. Soil physical and chemical properties in various sizes and development stages were studied in C. kawakamii natural forest gaps. The results showed that forest gaps in various sizes and development stages could improve soil pore space structure and water characteristics, which may effectively promote the water absorbing capacity for plant root growth and play an important role in forest regeneration. Soil pore space structure and water characteristics in small gaps showed more obvious improvements, followed by the medium and large gaps. Soil pore space structure and water characteristics in the later development stage of forest gaps demonstrated more obvious improvements, followed by the early and medium development stages. The contents of hydrolysable N and available K in various sizes and development stages of forest gaps were higher than those of non-gaps, whereas the contents of total N, total P, available P, organic matter, and organic carbon were lower. The contents of total N, hydrolysable N, available K, organic matter, and organic carbon in medium gaps were higher than those of large and small gaps. The disturbance of forest gaps could improve the soils’ physical and chemical properties and increase the population species’ richness, which would provide an ecological basis for the species coexistence in C. kawakamii natural forest. PMID:26496710

  11. Approach of regionalisation c-stocks in forest soils on a national level

    NASA Astrophysics Data System (ADS)

    Wellbrock, Nicole; Höhle, Juliane; Dühnelt, Petra; Holzhausen, Marieanna

    2010-05-01

    Introduction In December 2006, the German government decided to manage forests as carbon sinks to reduce greenhouse gas emissions in accordance with Article 3.4 of the Kyoto Protocol. The National Forest Monitoring data contribute to the fulfilment of these reporting commitments. In Germany, National Forest Monitoring includes the systematical extensive National Soil Condition Survey (BZE) and the detailed case studies (Level-II) which determine the processes within forests. This complex monitoring system is appropriate to Germany's greenhouse gas reporting (THG 2008 to 2012). The representative BZE plots can be used to obtain regional data for the National Carbon Stock Inventory. Here, an approach adopting a combination of geostatistics and regression analysis is preferred. The difficulty of showing the statistical significance of expected small changes while carbon stocks are generally high is one of the major challenges in carbon stock monitoring. However, through intensive preparation and cooperation with the forestry authorities of each federal state, the errors uncured in determining changes in carbon stocks in forest soils, which must be stipulated in greenhouse gas monitoring, could be minimised. In contrast to the detailed soil case studies, in which essentially the sources of error occur repeatedly in carbon stock change calculations, the BZE data can be stratified to form plots with homogenous properties, thereby reducing the standard error of estimate. Subsequently, the results of the stratification are projected across Germany, the reporting unit for greenhouse gas monitoring. National Forest Monitoring The BZE represents a national, systematic sampling inventory of the condition of forest soils. The first BZE inventory (BZE I: 1987 to 1993) was carried out on a systematic 8 x 8 km grid on the same sampling plots adopted in the Forest Condition Survey (WZE). In some areas the network of sampling plots involves 1900 grid points. The first BZE I survey

  12. Coastal Plain Soil Fertility Degradation And Natural Forest Ecosystem Regeneration

    NASA Astrophysics Data System (ADS)

    Casagrande, J. C.; Sato, C. A.; Reis-Duarte, R. M.; Soares, M. R.; Galvão Bueno, M. S.

    2009-04-01

    The sand coastal plain vegetation (Restinga Forest) has been described as an ecosystem associated with the Atlantic Forest, constituted of mosaics, which occur in areas of great ecological diversity, particularly the features of the soil which mostly influence the forest, therefore assigned as edaphic community. The Restinga forest is one of the most fragile, showing low resilience to human damage This work was carried out in several points (14) of Restinga Forest (six low - trees from 3 to 10 m high - and eight high forest - trees from 10 to 15 m high) in the litoral coast of the state of São Paulo. Each sample was made of 15 subsamples of each area collected in each depth (one in 0 - 5, 5 - 10, 10 - 15, 15 - 20, and another in 0 - 20, 20 - 40, 40 and 60 cm). Soil characteristics analyzed were pH, P, Na, K, Ca, Mg, S, H + Al, Al, B, Cu, Fe, Mn, Zn contents and base saturation, cation exchange capacity and aluminum saturation. The vegetation physiognomies of Restinga forest (low and high) were associated with soil results and with the history of human occupation. The soils are sandy (2 to 4% of clay), resulting in a low capacity of nutrient retention. Soil fertility analysis to low and high Restinga forest were similar and showed very low contents of phosphorous, calcium and magnesium in all areas investigated. The base saturation was low due to low amounts of Na, K, Ca and Mg. Base saturation presents low level in all cases, less than 10, indicating low nutritional reserve in the soil. The aluminum saturation values varied from 58 to 69%. The level of calcium and magnesium were low in the subsurface soil layer mainly, associate with high aluminum saturation, representing an limiting factor for the root system development in depth. If soil fertility parameters do not show any significant difference between low and high Restinga physiognomy, what make distinction is the recuperation time. In the areas of high Forest can be note a too long time of recuperation

  13. Boreal forest soil erosion and soil-atmosphere carbon exchange

    NASA Astrophysics Data System (ADS)

    Billings, S. A.; Harden, J. W.; O'Donnell, J.; Sierra, C. A.

    2013-12-01

    did not induce meaningful changes in model estimates of atmospheric C source or sink strength, likely due to the low turnover rate of SOC in this system. However, variation in mineral soil erosion rates induced large shifts in the source and sink strengths for atmospheric C; after 50 y of mineral soil erosion at 5 cm y-1, we observed a maximum C source of 35 kg C m-2 and negligible sink strength. Doubling the erosion rate approximately doubled the source strength. Scaling these estimates to the region requires estimates of the area undergoing mineral soil erosion in forests similar to those modeled. We suggest that erosion is an important but little studied feature of fire-driven boreal systems that will influence atmospheric CO2 budgets.

  14. Biogeographic patterns of soil diazotrophic communities across six forests in the North America.

    PubMed

    Tu, Qichao; Deng, Ye; Yan, Qingyun; Shen, Lina; Lin, Lu; He, Zhili; Wu, Liyou; Van Nostrand, Joy D; Buzzard, Vanessa; Michaletz, Sean T; Enquist, Brian J; Weiser, Michael D; Kaspari, Michael; Waide, Robert B; Brown, James H; Zhou, Jizhong

    2016-06-01

    Soil diazotrophs play important roles in ecosystem functioning by converting atmospheric N2 into biologically available ammonium. However, the diversity and distribution of soil diazotrophic communities in different forests and whether they follow biogeographic patterns similar to macroorganisms still remain unclear. By sequencing nifH gene amplicons, we surveyed the diversity, structure and biogeographic patterns of soil diazotrophic communities across six North American forests (126 nested samples). Our results showed that each forest harboured markedly different soil diazotrophic communities and that these communities followed traditional biogeographic patterns similar to plant and animal communities, including the taxa-area relationship (TAR) and latitudinal diversity gradient. Significantly higher community diversity and lower microbial spatial turnover rates (i.e. z-values) were found for rainforests (~0.06) than temperate forests (~0.1). The gradient pattern of TARs and community diversity was strongly correlated (r(2)  > 0.5) with latitude, annual mean temperature, plant species richness and precipitation, and weakly correlated (r(2)  < 0.25) with pH and soil moisture. This study suggests that even microbial subcommunities (e.g. soil diazotrophs) follow general biogeographic patterns (e.g. TAR, latitudinal diversity gradient), and indicates that the metabolic theory of ecology and habitat heterogeneity may be the major underlying ecological mechanisms shaping the biogeographic patterns of soil diazotrophic communities. PMID:27085668

  15. Variability in Soil Moisture in a Temperate Deciduous Forest Using Electrical Resistivity and Throughfall Data

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Van Dam, R. L.; Jayawickreme, D.

    2013-12-01

    In deciduous forests, soil moisture is an important driver of energy and carbon cycling, as well as ecosystem dynamics. The amount and distribution of soil moisture also influences soil microbial activity, nutrient fluxes, and groundwater recharge. Consequently, accurate characterization of interactions and interdependencies between vegetation and soil moisture is critical to forecast water resources and ecosystem health in a changing climate. Such relationships and processes are nevertheless difficult to measure, both in time and space because of our limited ability to monitor the subsurface at necessary scales and frequencies. Several recent studies have shown that electrical resistivity tomography (ERT), using an array of minimally invasive surface electrodes, is a promising method for in-situ soil moisture monitoring. To this point, however, only few studies have used ERT to investigate spatial variability of soil moisture in temperate deciduous forests and to explore any links between soil water and above ground ecosystem variables. In our study in a central Michigan (USA) maple forest during the 2012 growing season, we combined ERT with detailed vegetation surveys and throughfall measurements to obtain better insight into spatial variations in rainwater input and soil water patterns. Resistivity data were collected on a weekly basis along an array of 84 electrodes with a spacing of 1.5 m. The inversion results were temperature corrected, converted to soil moisture, and differenced to obtain 2D images of soil moisture changes. The throughfall data were obtained using a novel method based on dissolution of plaster-of-paris tablets that were positioned below funnels, at 19 locations in the forest. Our results show that: 1) resistivity changes spatially with vegetation distribution, 2) in-season temporal changes in resistivity are related to plant characteristics, in particular to tree count and basal area, and 3) our low-budget throughfall method was capable of

  16. 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.

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

    SciTech Connect

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

    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 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.

  18. Seedling growth responses to soil resources in the understory of a wet tropical forest.

    PubMed

    Holste, Ellen K; Kobe, Richard K; Vriesendorp, Corine F

    2011-09-01

    Plant growth responses to resources may be an important mechanism that influences species' distributions, coexistence, and community structure. Irradiance is considered the most important resource for seedling growth in the understory of wet tropical forests, but multiple soil nutrients and species have yet to be examined simultaneously with irradiance under field conditions. To identify potentially limiting resources, we modeled tree seedling growth as a function of irradiance and soil nutrients across five sites, spanning a soil fertility gradient in old-growth, wet tropical forests at La Selva Biological Station, Costa Rica. We measured an array of soil nutrients including total nitrogen (total N), inorganic N (nitrate [NO3-] and ammonium [NH4+]), phosphate (PO4-), and sum of base cations (SBC; potassium, magnesium, and calcium). Shade in the forest understory did not preclude seedling growth correlations with soil nutrients. Irradiance was a significant predictor of growth in 52% of the species, inorganic N in 54% (NO3- in 32%; NH4+ in 34%), total N in 47%, SBC in 39%, and PO4- in 29%. Overall, growth was correlated with both irradiance and soil nutrients in 45% of species and with soil nutrients only in an additional 48%; rarely was irradiance alone correlated with growth. Contrary to expectations, the magnitudes of growth effects, assessed as the maximum growth response to significant resources for each species, were similar for irradiance and most soil nutrients. Among species whose growth correlated with soil nutrients, the rank importance of nutrient effects was SBC, followed by N (total N, NO3-, and/or NH4+) and PO4-. Species' growth responsiveness (i.e., magnitudes of effect) to irradiance and soil nutrients was negatively correlated with species' shade tolerance (survival under 1% full sun). In this broad survey of species and resources, the nearly ubiquitous effects of soil nutrients on seedling growth challenge the idea that soil nutrients are less

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

    SciTech Connect

    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 incorporates all amendments approved to date and published in National Soil Taxonomy Handbook (NSTH) Issues 1-17.

  20. Soil organic carbon of European forest soils: current stock and projections under climate change conditions

    NASA Astrophysics Data System (ADS)

    Caddeo, Antonio; Marras, Serena; Spano, Donatella; Sirca, Costantino

    2016-04-01

    Soil organic carbon (SOC) represents the largest terrestrial carbon pool, and it is subjected to climate change impacts. In Europe, a limited number of studies makes a wide-scale comparison of SOC stock and changes under climate change conditions, and most of them are related to agricultural soils. In this work, the SOC stock of the forested areas of Europe (obtained from the CORINE 2006 Land Use Map) was assessed at 1 km resolution using the agro-ecosystem SOC model CENTURY. The results of the model were compared with independent observational datasets (i.e. LUCAS Topsoil Survey Database). In addition, climate simulations (RCPs 4.5 and 8.5) using the CMCC (Euro-Mediterranean Centre on Climate Change) and the CORDEX dataset were used to estimate the SOC changes of these areas under climate change conditions.

  1. FOREST SOIL CARBON SEQUESTRATION: ACCOUNTING FOR THIS VITAL ECOSYSTEM SERVICE

    EPA Science Inventory

    Forests play a crucial role in supplying many goods and services that society depends upon on a daily basis including water supply, production of oxygen, soil protection, building materials, wildlife habitat and recreation. Forests also provide a significant amount of carbon seq...

  2. Use of multispectral data in design of forest sample surveys

    NASA Technical Reports Server (NTRS)

    Titus, S. J.; Wensel, L. C.

    1977-01-01

    The use of multispectral data in design of forest sample surveys using a computer software package is described. The system allows evaluation of a number of alternative sampling systems and, with appropriate cost data, estimates the implementation cost for each.

  3. Windthrows increase soil carbon stocks in a Central Amazon forest

    NASA Astrophysics Data System (ADS)

    dos Santos, L. T.; Magnabosco Marra, D.; Trumbore, S.; Camargo, P. B.; Chambers, J. Q.; Negrón-Juárez, R. I.; Lima, A. J. N.; Ribeiro, G. H. P. M.; dos Santos, J.; Higuchi, N.

    2015-12-01

    Windthrows change forest structure and species composition in Central Amazon forests. However, the effects of widespread tree mortality associated with wind-disturbances on soil properties have not yet been described. In this study, we investigated short-term effects (seven years after disturbance) of a windthrow event on soil carbon stocks and concentrations in a Central Amazon terra firme forest. The soil carbon stock (averaged over a 0-30 cm depth profile) in disturbed plots (61.4 ± 4.18 Mg ha-1, mean ± standard error) was marginally higher (p = 0.009) than that from undisturbed plots (47.7 ± 6.95 Mg ha-1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.08 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.12 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r = 0.575 and p = 0.019) and with tree mortality intensity (r = 0.493 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. Higher nutrient availability in soils from large canopy gaps created by wind disturbance may increase vegetation resilience and favor forest recovery.

  4. Soil phosphorus and the ecology of lowland tropical forests

    NASA Astrophysics Data System (ADS)

    Turner, Ben

    2016-04-01

    In this presentation I will explore the extent to which phosphorus influences the productivity, diversity, and distribution of plant species in tropical forests. I will highlight the range of soils that occur in tropical forests and will argue that pedogenesis and associated phosphorus depletion is a primary driver of forest diversity over long timescales. I will draw on data from a regional-scale network of forest dynamics plots in Panama to show that tree species distributions are determined predominantly as a function of dry season intensity and soil phosphorus availability, and will suggest potential mechanistic explanations for this pattern in relation to phosphorus acquisition. Finally, I will present observational and experimental evidence from Panama to show how phosphorus, nitrogen, and potassium, limit plant productivity and microbial communities on strongly-weathered soils in the lowland tropics.

  5. SOLUBLE ALUMINUM IN ACIDIFIED ORGANIC HORIZONS OF FOREST SOILS

    EPA Science Inventory

    Concentrations of labile and total Al in soil extracts were measured as a function of equilibrium solution pH in six forest soil organic horizons acidified with HNO, (0-20 cmol H+.kg-1) under controlled conditions of ionic strength (0.05 M NaNO3), temperature (23 C), and solution...

  6. LIGNIN DEGRADATION IN GRASSLAND, FOREST, AND SHRUB-STEPPE SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin decomposition was studied in soils from research plots in 5 locations in the US: restored tallgrass prairie, farmland (grain), semiarid shrub-steppe, and loblolly pine and Douglas fir forests. Soils were amended with 14C- lignocellulose and incubated for 6 months during which total- and 14C-C...

  7. Long-term forest soil warming alters microbial communities in temperate forest soils

    PubMed Central

    DeAngelis, Kristen M.; Pold, Grace; Topçuoğlu, Begüm D.; van Diepen, Linda T. A.; Varney, Rebecca M.; Blanchard, Jeffrey L.; Melillo, Jerry; Frey, Serita D.

    2015-01-01

    Soil microbes are major drivers of soil carbon cycling, yet we lack an understanding of how climate warming will affect microbial communities. Three ongoing field studies at the Harvard Forest Long-term Ecological Research (LTER) site (Petersham, MA) have warmed soils 5°C above ambient temperatures for 5, 8, and 20 years. We used this chronosequence to test the hypothesis that soil microbial communities have changed in response to chronic warming. Bacterial community composition was studied using Illumina sequencing of the 16S ribosomal RNA gene, and bacterial and fungal abundance were assessed using quantitative PCR. Only the 20-year warmed site exhibited significant change in bacterial community structure in the organic soil horizon, with no significant changes in the mineral soil. The dominant taxa, abundant at 0.1% or greater, represented 0.3% of the richness but nearly 50% of the observations (sequences). Individual members of the Actinobacteria, Alphaproteobacteria and Acidobacteria showed strong warming responses, with one Actinomycete decreasing from 4.5 to 1% relative abundance with warming. Ribosomal RNA copy number can obfuscate community profiles, but is also correlated with maximum growth rate or trophic strategy among bacteria. Ribosomal RNA copy number correction did not affect community profiles, but rRNA copy number was significantly decreased in warming plots compared to controls. Increased bacterial evenness, shifting beta diversity, decreased fungal abundance and increased abundance of bacteria with low rRNA operon copy number, including Alphaproteobacteria and Acidobacteria, together suggest that more or alternative niche space is being created over the course of long-term warming. PMID:25762989

  8. Soil Quality Index Determination Models for Restinga Forest

    NASA Astrophysics Data System (ADS)

    Bonilha, R. M.; Casagrande, J. C.; Soares, R. M.

    2012-04-01

    The Restinga Forest is a set of plant communities in mosaic, determined by the characteristics of their substrates as a result of depositional processes and ages. In this complex mosaic are the physiognomies of restinga forests of high-stage regeneration (high restinga) and middle stage of regeneration (low restinga), each with its plant characteristics that differentiate them. Located on the coastal plains of the Brazilian coast, suffering internal influences both the continental slopes, as well as from the sea. Its soils come from the Quaternary and are subject to constant deposition of sediments. The climate in the coastal type is tropical (Köppen). This work was conducted in four locations: (1) Anchieta Island, Ubatuba, (2) Juréia-Itatins Ecological Station, Iguape, (3) Vila das Pedrinhas, Comprida Island; and (4) Cardoso Island, Cananeia. The soil samples were collect at a depths of 0 to 5, 0-10, 0-20, 20-40 and 40 to 60cm for the chemical and physical analysis. Were studied the additive and pondering additive models to evaluate soil quality. It was concluded: a) the comparative additive model produces quantitative results and the pondering additive model quantitative results; b) as the pondering additive model, the values of Soil Quality Index (SQI) for soils under forest of restinga are low and realistic, demonstrating the small plant biomass production potential of these soils, as well as their low resilience; c) the values of SQI similar to areas with and without restinga forest give quantitative demonstration of the restinga be considered as soil phase; d) restinga forest, probably, is maintained solely by the cycling of nutrients in a closed nutrient cycling; e) for the determination of IQS for soils under restinga vegetation the use of routine chemical analysis is adequate. Keywords: Model, restinga forest, Soil Quality Index (SQI).

  9. Characterization of soil microarthropod communities in Italian beech forest

    NASA Astrophysics Data System (ADS)

    Conti, F. D.; Menta, C.; Piovesan, G.

    2009-04-01

    The contribution of soil organisms to ecosystem functions such as decomposition, nutrient recycling and the maintenance of physico-chemical properties is well recognised, as is the fact that soil fauna plays an important role in the formation and stabilisation of soil structure. The diversity of soil fauna includes a quarter of described living species, the majority of which are insects and arachnids. Soil fauna plays an essential role in forests and agro-ecosystems by maintaining their functionality and productivity. The aim of this study is to evaluate the biodiversity of soil microarthropods communities in different Italian beech forest. Particular attention is paid to the role of fossorial microarthropods in the maintenance of soil structure and in the organic matter movements. Three beech forests are studied, two located in the North and one in the Centre of Italy. Microarthropods are extracted from litter and soil with a Berlese-Tullgren funnel, identified to order level (class level for myriapods) and counted using a microscope. Relative order abundance and biodiversity are expressed using the Shannon-Weaver diversity index (H) and evenness index (J). Soil biological quality is expressed using the QBS-ar index and Acari/Collembola ratio. The results show a richness of microarthropods: several orders, till 19 different groups, are determined and identified. Acari and collembola are the main represented taxa and, especially in litter samples, pseudoscorpions, different specimens of diplopods (or millipedes) and chilopods (centipedes) are found. Thus the presence in particular of diplopods offers the possibility of studying fossorial microarthropods functions in detail. Furthermore, both in soil and in litter samples, adapted groups are recognized, such as pauropods, symphyla, proturans and diplurans, with specific morphological characteristics that these species suited to soil habitat. Therefore they attest a good level of soil quality and high natural value

  10. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    NASA Astrophysics Data System (ADS)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and increase thereby the soil CO2 efflux. Elevated microbial activity might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. We here investigated the chemical and isotopic composition of bulk soil and three different density fractions of forest soils from a long term warming experiment in the Austrian Alps. At the time of sampling the soils in this experiment had been warmed during the snow-free period for 8 consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results which included organic C content, total N content, δ13C, δ 14C, δ 15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. The differences in the three individual fractions (free particulate organic matter, occluded particulate organic matter and mineral associated organic matter) were mostly small and the direction of warming induced change was variable with fraction and sampling depth. We did however find statistically significant effects of warming in all density fractions from 0-10 cm depth, 10-20 cm depth or both. Our results also including significant changes in the supposedly more stable mineral associated organic matter fraction where δ 13C values decreased at both sampling depths and the relative proportion of N-bearing compounds decreased at a sampling depth of 10-20 cm. All the observed changes can be attributed to an interplay of enhanced microbial decomposition of SOM and increased root litter input. This study suggests that soil warming destabilizes all density fractions of

  11. LANDSAT, a data supplement to forest survey

    NASA Technical Reports Server (NTRS)

    Thiede, G.

    1981-01-01

    The use of LANDSAT in providing forest data on a county basis was investigated. Image interpretation and classification techniques and their accuracy are addressed. LANDSAT data was also used to detect and delineate defoliation caused by tent caterpillars.

  12. EVALUATION OF METRIC PRECISION FOR A RIPARIAN FOREST SURVEY

    EPA Science Inventory

    This paper evaluates the performance of a protocol to monitor riparian forests in western Oregon based on the quality of the data obtained from a recent field survey. Precision and accuracy are the criteria used to determine the quality of 19 field metrics. The field survey con...

  13. Soil warming, carbon–nitrogen interactions, and forest carbon budgets

    PubMed Central

    Melillo, Jerry M.; Butler, Sarah; Johnson, Jennifer; Mohan, Jacqueline; Steudler, Paul; Lux, Heidi; Burrows, Elizabeth; Bowles, Francis; Smith, Rose; Scott, Lindsay; Vario, Chelsea; Hill, Troy; Burton, Andrew; Zhou, Yu-Mei; Tang, Jim

    2011-01-01

    Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon–nitrogen interactions in atmosphere–ocean–land earth system models to accurately simulate land feedbacks to the climate system. PMID:21606374

  14. Soil microbial community successional patterns during forest ecosystem restoration.

    PubMed

    Banning, Natasha C; Gleeson, Deirdre B; Grigg, Andrew H; Grant, Carl D; Andersen, Gary L; Brodie, Eoin L; Murphy, D V

    2011-09-01

    Soil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mining (up to 18 years old), to examine changes in soil bacterial and fungal community structures (by automated ribosomal intergenic spacer analysis [ARISA]) and changes in specific soil bacterial phyla by 16S rRNA gene microarray analysis. This study demonstrated that mining in these ecosystems significantly altered soil bacterial and fungal community structures. The hypothesis that the soil microbial community structures would become more similar to those of the surrounding nonmined forest with rehabilitation age was broadly supported by shifts in the bacterial but not the fungal community. Microarray analysis enabled the identification of clear successional trends in the bacterial community at the phylum level and supported the finding of an increase in similarity to nonmined forest soil with rehabilitation age. Changes in soil microbial community structure were significantly related to the size of the microbial biomass as well as numerous edaphic variables (including pH and C, N, and P nutrient concentrations). These findings suggest that soil bacterial community dynamics follow a pattern in developing ecosystems that may be predictable and can be conceptualized as providing an integrated assessment of numerous edaphic variables. PMID:21724890

  15. Soil warming, carbon-nitrogen interactions, and forest carbon budgets.

    PubMed

    Melillo, Jerry M; Butler, Sarah; Johnson, Jennifer; Mohan, Jacqueline; Steudler, Paul; Lux, Heidi; Burrows, Elizabeth; Bowles, Francis; Smith, Rose; Scott, Lindsay; Vario, Chelsea; Hill, Troy; Burton, Andrew; Zhou, Yu-Mei; Tang, Jim

    2011-06-01

    Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon-nitrogen interactions in atmosphere-ocean-land earth system models to accurately simulate land feedbacks to the climate system. PMID:21606374

  16. Inhibition of methane consumption in forest soils by monoterpenes

    SciTech Connect

    Amaral, J.A.; Knowles, R.

    1998-04-01

    Selected monoterpenes were tested for their ability to inhibit atmospheric methane consumption by three forest soils from different vegetation types and by the cultured methanotrophic strain, Methylosinus trichosporium OB3b. Subsurface soil from coniferous (Pinus banksiana), deciduous (Populus tremuloides), and mixed hardwood (Tsuga canadensis and Prunus pensylvanica) stands was used under field-moist and slurry conditions. Most of the hydrocarbon monoterpenes tested significantly inhibited methane consumption by soils at environmentally relevant levels, with ({minus})-{alpha}-pinene being the most effective. With the exception of {beta}-myrcene, monoterpenes also strongly inhibited methane oxidation by Methylosinus trichosporium OB3b. Carbon dioxide production was stimulated in all of the soils by the monoterpenes tested. In one case, methane production was stimulated by ({minus})-{alpha}-pinene in an intact, aerobic core. Oxide and alcohol monoterpenoids stimulated methane production. Thus, monoterpenes appear to be potentially important regulators of methane consumption and carbon metabolism in forest soils.

  17. Soil organic matter regulates molybdenum storage and mobility in forests

    USGS Publications Warehouse

    Marks, Jade A; Perakis, Steven; King, Elizabeth K; Pett-Ridge, Julie

    2015-01-01

    The trace element molybdenum (Mo) is essential to a suite of nitrogen (N) cycling processes in ecosystems, but there is limited information on its distribution within soils and relationship to plant and bedrock pools. We examined soil, bedrock, and plant Mo variation across 24 forests spanning wide soil pH gradients on both basaltic and sedimentary lithologies in the Oregon Coast Range. We found that the oxidizable organic fraction of surface mineral soil accounted for an average of 33 %of bulk soil Mo across all sites, followed by 1.4 % associated with reducible Fe, Al, and Mn-oxides, and 1.4 % in exchangeable ion form. Exchangeable Mo was greatest at low pH, and its positive correlation with soil carbon (C) suggests organic matter as the source of readily exchangeable Mo. Molybdenum accumulation integrated over soil profiles to 1 m depth (τMoNb) increased with soil C, indicating that soil organic matter regulates long-term Mo retention and loss from soil. Foliar Mo concentrations displayed no relationship with bulk soil Mo, and were not correlated with organic horizon Mo or soil extractable Mo, suggesting active plant regulation of Mo uptake and/or poor fidelity of extractable pools to bioavailability. We estimate from precipitation sampling that atmospheric deposition supplies, on average, over 10 times more Mo annually than does litterfall to soil. In contrast, bedrock lithology had negligible effects on foliar and soil Mo concentrations and on Mo distribution among soil fractions. We conclude that atmospheric inputs may be a significant source of Mo to forest ecosystems, and that strong Mo retention by soil organic matter limits ecosystem Mo loss via dissolution and leaching pathways.

  18. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems.

    PubMed

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  19. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems

    PubMed Central

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  20. Elevated CO2 Effects on Mercury Content of Forest Soils

    NASA Astrophysics Data System (ADS)

    Natali, S. M.; Lerdau, M.; Sañudo-Wilhelmy, S. A.

    2006-12-01

    Fossil fuel combustion is the primary anthropogenic source of both CO2 and mercury (Hg) to the atmosphere. Terrestrial vegetation can act as a conduit for transferring atmospheric Hg into soils and freshwater systems. While the effects of CO2 on both terrestrial plants and soils have been well-studied, the impacts of these CO2 induced changes on Hg cycling are unknown. We found that elevated CO2 resulted in increased Hg concentration in forest soils. Soil Hg concentration in the top 20cm of soils was 26% greater and total Hg content was 22% greater under elevated CO2 (ambient + 200ppmv), relative to ambient at two FACE sites: Duke Forest, NC and Oak Ridge, TN. However, there was no significant CO2 effect on Hg inputs via leaf litter. Soil Hg was significantly correlated with soil organic matter and acidity, suggesting that CO2 mediated changes in soil properties may be affecting soil Hg content. Elevated atmospheric CO2 has the potential to increase the Hg trapping efficiency of soils, with still unknown effects on terrestrial and aquatic ecosystem function.

  1. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: a field manipulation experiment.

    PubMed

    Mazur, M; Mitchell, C P J; Eckley, C S; Eggert, S L; Kolka, R K; Sebestyen, S D; Swain, E B

    2014-10-15

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m(-2)d(-1)) were significantly greater than both the traditional clearcut plot (-40 ± 60 ng m(-2)d(-1)) and the un-harvested reference plot (-180 ± 115 ng m(-2)d(-1)) during July. This difference was likely a result of enhanced Hg(2+) photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest soils will increase, although it is not yet clear for

  2. Soil Respiration of Three Mangrove Forests on Sanibel Island, Florida

    NASA Astrophysics Data System (ADS)

    Cartwright, F.; Bovard, B. D.

    2011-12-01

    Carbon cycling studies conducted in mangrove forests have typically focused on aboveground processes. Our understanding of carbon storage in these systems is therefore limited by the lack information on belowground processes such as fine root production and soil respiration. To our knowledge there exist no studies investigating temporal patterns in and environmental controls on soil respiration in multiple types of mangrove ecosystems concurrently. This study is part of a larger study on carbon storage in three mangrove forests on Sanibel Island, Florida. Here we report on eight months of soil respiration data within these forests that will ultimately be incorporated into an annual carbon budget for each habitat type. Soil respiration was monitored in the following three mangrove habitat types: a fringe mangrove forest dominated by Rhizophora mangle, a basin mangrove forest dominated by Avicennia germinans, and a higher elevation forest comprised of a mix of Avicennia germinans and Laguncularia racemosa, and non-woody salt marsh species. Beginning in June of 2010, we measured soil emissions of carbon dioxide at 5 random locations within three-100 m2 plots within each habitat type. Sampling was performed at monthly intervals and conducted over the course of three days. For each day, one plot from each habitat type was measured. In addition to soil respiration, soil temperature, salinity and gravimetric moisture content were also measured. Our data indicate the Black mangrove forest, dominated by Avicennia germinans, experiences the highest rates of soil respiration with a mean rate of 4.61 ± 0.60 μmol CO2 m-2 s-1. The mixed mangrove and salt marsh habitat has the lowest soil carbon emission rates with a mean of 2.78 ± 0.40 μmol CO2 m-2 s-1. Soil carbon effluxes appear to peak in the early part of the wet season around May to June and are lower and relatively constant the remainder of the year. Our data also suggest there are important but brief periods where

  3. Windthrows increase soil carbon stocks in a central Amazon forest

    NASA Astrophysics Data System (ADS)

    dos Santos, Leandro T.; Magnabosco Marra, Daniel; Trumbore, Susan; de Camargo, Plínio B.; Negrón-Juárez, Robinson I.; Lima, Adriano J. N.; Ribeiro, Gabriel H. P. M.; dos Santos, Joaquim; Higuchi, Niro

    2016-03-01

    Windthrows change forest structure and species composition in central Amazon forests. However, the effects of widespread tree mortality associated with wind disturbances on soil properties have not yet been described in this vast region. We investigated short-term effects (7 years after disturbance) of widespread tree mortality caused by a squall line event from mid-January of 2005 on soil carbon stocks and concentrations in a central Amazon terra firme forest. The soil carbon stock (averaged over a 0-30 cm depth profile) in disturbed plots (61.4 ± 8.2 Mg ha-1, mean ±95 % confidence interval) was marginally higher (p = 0.09) than that from undisturbed plots (47.7 ± 13.6 Mg ha-1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.17 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.24 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r2 = 0.332, r = 0.575 and p = 0.019) and with tree mortality intensity (r2 = 0.257, r = 0.506 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. The higher carbon content and potentially higher nutrient availability in soils from areas recovering from windthrows may favor forest regrowth and increase vegetation resilience.

  4. Spatial variability of soils in a seasonally dry tropical forest

    NASA Astrophysics Data System (ADS)

    Pulla, Sandeep; Riotte, Jean; Suresh, Hebbalalu; Dattaraja, Handanakere; Sukumar, Raman

    2016-04-01

    Soil structures communities of plants and soil organisms in tropical forests. Understanding the controls of soil spatial variability can therefore potentially inform efforts towards forest restoration. We studied the relationship between soils and lithology, topography, vegetation and fire in a seasonally dry tropical forest in southern India. We extensively sampled soil (available nutrients, Al, pH, and moisture), rocks, relief, woody vegetation, and spatial variation in fire burn frequency in a permanent 50-ha plot. Lower elevation soils tended to be less moist and were depleted in several nutrients and clay. The availability of several nutrients was, in turn, linked to whole-rock chemical composition differences since some lithologies were associated with higher elevations, while the others tended to dominate lower elevations. We suggest that local-scale topography in this region has been shaped by the spatial distribution of lithologies, which differ in their susceptibility to weathering. Nitrogen availability was uncorrelated with the presence of trees belonging to Fabaceae, a family associated with N-fixing species. No effect of burning on soil parameters could be discerned at this scale.

  5. Implications of Using USDA-NCSS Bulk Density to Estimate Carbon Stocks in Forest Soils Across the Southeastern United States

    NASA Astrophysics Data System (ADS)

    Bacon, A. R.; Akers, K.; Cucinella, J.; Grunwald, S.; Jokela, E. J.; Markewitz, D.; Laviner, M. A.; Vogel, J. G.; Martin, T.; Fox, T. D.; Kane, M.; Peter, G. F.; Davis, J. M.; Ross, C. W.

    2015-12-01

    Estimates of soil bulk density (Db) are critical for accurate estimates of soil carbon (C) stocks, and thus, greatly influence the balance and interpretation of soil C budgets at plot, regional, and national scales. Large scale soil C investigations in the United States (US) almost always utilize a compilation of more than 20,000 Db observations across the US within the USDA-NRCS National Cooperative Soil Survey (NCSS) database. NCSS observations can be manually extracted as point data and then stratified or modeled by a variety of soil taxonomic, geographic, and environmental factors to estimate Db across large scales. NCSS observations also underpin the popular Soil Survey Geographic (SSURGO) database which provides continuous Db estimates across most of the US. Here, for the first time, we evaluate the precision and accuracy with which NCSS data can estimate forest soil Db across the southeastern United States and explore how using these observations impacts soil C budgets in forests across the region. We analyze and compare nearly 3,000 Db observations from the NCSS database to nearly 1,500 Db observations from the PINEMAP Tier II Network (325 experimental forest plots) across the southeastern US. We model all NCSS observations and 70% of the PINEMAP Tier II observations (a calibration dataset) separately with Random Forest algorithms to create a variety of Db predictive models at 0-10, 10-20, 20-50, and 50-100 cm depths. We validate all models against 30% of the PINEMAP Tier II observations (a validation dataset). As indexed by the mean prediction error (MPE), NCSS observations tend to over predict forest soil Db across the validation dataset by an average of 0.20 g/cc. Incorporating this positive bias of NCSS Db predictions into C stock estimates in the top 100 cm of soil across the PINEMAP Tier II network inflates C stock estimates by an average of 13 Mg/ha. Our findings identify significant potential for NCSS observations to over predict soil Db, and thus

  6. Shifts in soil testate amoeba communities associated with forest diversification.

    PubMed

    Bobrov, Anatoly A; Zaitsev, Andrei S; Wolters, Volkmar

    2015-05-01

    We studied changes of testate amoeba communities associated with the conversion of spruce monocultures into mixed beech-fir-spruce forests in the Southern Black Forest Mountains (Germany). In this region, forest conversion is characterized by a gradual development of beech undergrowth within thinned spruce tree stands leading to multiple age continuous cover forests with a diversified litter layer. Strong shifts in the abundance of testate amoeba observed in intermediate stages levelled off to monoculture conditions again after the final stage of the conversion process had been reached. The average number of species per conversion stage (i.e., local richness) did not respond strongly to forest conversion, but the total number of species (i.e., regional richness) was considerably higher in the initial stage than in the mixed forests, due to the large number of hygrophilous species inhabiting spruce monocultures. Functional diversity of the testate amoeba community, however, significantly increased during the conversion process. This shift was closely associated with improved C and N availability as well as higher niche diversity in the continuous cover stands. Lower soil acidity in these forests coincided with a higher relative abundance of eurytopic species. Our results suggest that testate amoeba communities are much more affected by physicochemical properties of the soil than directly by litter diversity. PMID:25820471

  7. Changing Boreal Fire Regimes: Impacts on Permafrost Soils and Forest Succession in Siberian Larch Forests

    NASA Astrophysics Data System (ADS)

    Alexander, H. D.; Mack, M. C.; Natali, S.; Loranty, M. M.; Davydov, S. P.; Zimov, N.

    2014-12-01

    Fire activity has increased across the boreal forest biome in conjuction with climate warming and drying. Because these forests contain a large proportion of global terrestrial carbon (C) stocks, there has been great interest in understanding feedbacks between a changing fire regime and climate warming. An important mechanism by which increased fire activity may alter boreal C balance is by consuming the soil organic layer (SOL). Fire removal of the SOL may alter germination microsites and tree recruitment, thereby altering forest successional trajectories and C accumulation and storage. In permafrost soils, loss of the insulating SOL can increase soil temperature and active layer depth, impacting growth and survival conditions for both soil microbes and vegetation. To assess fire severity effects on permafrost soils and tree recruitment, we conducted plot-level experimental burns in July 2012 in a larch forest near Cherskii, Siberia. We achieved four burn severity treatments based on residual SOL depths: control, low (> 8 cm), moderate (5-8 cm), and high severity (2-5 cm). For two growing seasons post-fire, we measured thaw depth, soil moisture, and soil temperature. We sowed larch seeds in fall 2012 and 2013 and quantified seedling establishment and vegetation re-growth for two growing seasons. Immediately post-fire, thaw depth increased rapidly with increasing fire severity, and this trend has persisted for two years. In 2013 and 2014, thaw depth was ~ 40 cm deeper in high severity plots compared to controls, likely due to lower summer soil insulation, higher black char cover, and higher surface soil temperatures. We observed little to no larch recruitment in unburned and low severity plots, but new seedling density was ~5 seedlings m-2 in moderate and high severity plots, which had low cover of other vegetation types and high soil moisture. Findings suggest that increased fire severity may increase larch recruitment and provide favorable soil conditions for

  8. Redistribution and Destabilization of Forest Soil Carbon by Earthworm Invasion

    NASA Astrophysics Data System (ADS)

    Swanston, C. W.; Torn, M. S.; Allen, L.; Lilleskov, E. A.; Maggi, F.

    2008-12-01

    Soils of temperate forests in the northern Great Lakes region have developed in the absence of earthworms, which were largely eradicated during the last ice age. European earthworms, such as Lumbricus terrestris, are spreading and their effect on forest soil C has not been widely studied. We examined soils along a chronosequence of worm activity (wormosequence) ranging from no apparent activity (Low) to high activity over several decades (High). In the soil profile, including organic horizons, there was only a small loss (4%) of C with high worm activity. There was a 71% decrease in the Oe and no remaining Oa in the High site. Conversely, the mineral soil contained 25% more C in the High site, with most of that in the top 20 cm. We densimetrically separated the mineral soil into primarily organic free light fraction (FLF) and occluded light fraction (OLF), a mineral-associated intermediate fraction (IF), and a mineral-associated dense fraction (DF). We measured fraction mass, C, nitrogen, and 14C content. In comparison to Low sites, each depth of High worm soil had less FLF C and more IF C. With worms, more C was stored in aggregates in the upper soil but less in the lower soil. The presence of worms had a very large effect on the 14C content of soil organic matter, with shifts of > 60 per mil in several fractions presumably due to a combination of vertical redistribution and more rapid transfer into and out of some fractions. For example, from the Low to High sites OLF 14C increased 100 per mil at 0-10 cm depth, while DF 14C decreased 80 per mil at 20-50 cm. The effect of worms on C cycling can be explored using a multi-pool, multi-depth model that treats 14C as a conservative (i.e., stable) tracer. Our results suggest that worms play a major role in redistributing soil C in these forest soils by pathways that differ with depth: the upper soil loses FLF C and incorporates organic horizon C into OLF and IF, whereas in the lower depths FLF is lost and the previously

  9. Land use, forest density, soil mapping, erosion, drainage, salinity limitations

    NASA Technical Reports Server (NTRS)

    Yassoglou, N. J. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. The results of analyses show that it is possible to obtain information of practical significance as follows: (1) A quick and accurate estimate of the proper use of the valuable land can be made on the basis of temporal and spectral characteristics of the land features. (2) A rather accurate delineation of the major forest formations in the test areas was achieved on the basis of spatial and spectral characteristics of the studied areas. The forest stands were separated into two density classes; dense forest, and broken forest. On the basis of ERTS-1 data and the existing ground truth information a rather accurate mapping of the major vegetational forms of the mountain ranges can be made. (3) Major soil formations are mapable from ERTS-1 data: recent alluvial soils; soil on quarternary deposits; severely eroded soil and lithosol; and wet soils. (4) An estimation of cost benefits cannot be made accurately at this stage of the investigation. However, a rough estimate of the ratio of the cost for obtaining the same amount information from ERTS-1 data and from conventional operations would be approximately 1:6 to 1:10, in favor of the ERTS-1.

  10. Taxonomic and functional diversity of Streptomyces in a forest soil.

    PubMed

    Bontemps, Cyril; Toussaint, Maxime; Revol, Pierre-Vincent; Hotel, Laurence; Jeanbille, Mathilde; Uroz, Stéphane; Turpault, Marie-Pierre; Blaudez, Damien; Leblond, Pierre

    2013-05-01

    In this work we report the isolation and the characterization of 79 Streptomyces isolates from a French forest soil. The 16S rRNA gene phylogeny indicated that a great diversity of Streptomyces was present in this soil, with at least nine different and potentially new species. Growth plate assays showed that most Streptomyces lineages exhibit cellulolytic and hemicellulolytic capacities and potentially participate in wood decomposition. Molecular screening for a specific hydrogenase also indicated a widespread potential for atmospheric H2 uptake. Co-culture experiments with representative strains showed antagonistic effects between Streptomyces of the same population and between Streptomyces and various fungi. Interestingly, in certain conditions, growth promotion of some fungi also occurred. We conclude that in forest soil, Streptomyces populations exhibit many important functions involved in different biogeochemical cycles and also influence the structure of soil microbial communities. PMID:23489323

  11. Continuous Monitoring of Soil Respiration in Black Spruce Forest Soils, Interior Alaska

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Kim, S.; Kim, W.

    2009-12-01

    This research was carried out to estimate the continuous monitoring of soil respiration using automatic chamber system that was equipped with a control system, a compressor, and seven chambers (50 cm diameter, 30 cm high) set in sphagnum moss, feather moss, lichen, and tussock in black spruce forest soils, interior Alaska during growing season of 2008. The average daily soil respirations were 0.050±0.012 (standard deviation, CV 23%), 0.022±0.020 (91%), 0.082±0.035 (43%), and 0.027±0.010 mgCO2/m2/s (37%) in lichens, sphagnum moss, tussock and feather moss on black spruce forest soils with light chamber made by transparent material. The temporal variation of soil respiration in different vegetation types on black spruce forest soils during the growing season of 2008 is shown in Figure 1. The accumulative daily soil respiration was 5.2, 9.5, 2.3, and 2.8 mgCO2/m2/s in lichen, tussock, sphagnum moss, and feather moss of black spruce forest ground during the growing periods of 103 days, 2008 (Figure 2). Therefore, averaged regional soil respiration rate is 0.19±0.18 and 0.12±0.08 kgC/m2/(growing season) of 2007 and 2008 in black spruce forest soils, interior Alaska. The winter soil respiration was 0.049±0.013 gC/m2/(winter season), corresponding from 21±7% to 29±13% of the annual CO2 emitted from black spruce forest soils, interior Alaska.

  12. BOREAS TE-22 Allometric Forest Survey Data

    NASA Technical Reports Server (NTRS)

    Shugart, H. H.; Nielsen, Eric; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-22 (Terrestrial Ecology) team collected data sets in support of its efforts to characterize and interpret information on the forest structure of boreal vegetation in the Southern and Northern Study Areas (SSA and NSA) during the 1994 growing season. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  13. Mapping organic carbon stocks of Swiss forest soil

    NASA Astrophysics Data System (ADS)

    Nussbaum, M.; Papritz, A.; Baltensweiler, A.; Walthert, L.

    2012-04-01

    Carbon (C) sequestration into forest sinks offsets greenhouse gas emissions under the Kyoto protocol. Therefore, quantifying C stocks and fluxes in forest ecosystems is of interest for reporting greenhouse gas emissions. In Switzerland, the National Forest Inventory offers comprehensive data to quantify the above ground forest biomass and its change in time. Estimating stocks of soil organic C (SOC) in forests is more difficult because of its high spatial variability. To date the greenhouse gas inventory relies only on sparse data and regionally differentiated predictions of SOC stocks in forest soils are currently not possible. Recently, more soil data and new explanatory variables for statistical modeling like high resolution elevation data and satellite images became available. Based on data from 1'033 sites, we modeled SOC stocks to a depth of 1 m including the organic layer for the Swiss forested area. We used a novel robust restricted maximum likelihood method to fit a linear regression model with spatially correlated errors to the C stock data. For the regression analysis we used a broad range of covariates derived from climate data (precipitation, temperature, radiation), two elevation models (resolutions 25 and 2 m) and spectral variables representing vegetation. Furthermore, the main cartographic categories of an overview soil map were used to broadly represent the parent material. The numerous covariates, that partly correlated strongly, were reduced to a first subset using LASSO (Least Absolute Shrinkage and Selection Operator). This subset of covariates was then further reduced based on cross validation of the robustly fitted spatial model. The levels of categorical covariates were partly aggregated during this process and interactions between covariates were explored to account for nonlinear dependence of C stocks on the covariates. Using the final model, robust kriging prediction and error maps were computed with a resolution of one hectare.

  14. Nitrogen release from forest soils containing sulfide-bearing sediments

    NASA Astrophysics Data System (ADS)

    Maileena Nieminen, Tiina; Merilä, Päivi; Ukonmaanaho, Liisa

    2014-05-01

    Soils containing sediments dominated by metal sulfides cause high acidity and release of heavy metals, when excavated or drained, as the aeration of these sediments causes formation of sulfuric acid. Consequent leaching of acidity and heavy metals can kill tree seedlings and animals such as fish, contaminate water, and corrode concrete and steel. These types of soils are called acid sulfate soils. Their metamorphic equivalents, such as sulfide rich black shales, pose a very similar risk of acidity and metal release to the environment. Until today the main focus in treatment of the acid sulfate soils has been to prevent acidification and metal toxicity to agricultural crop plants, and only limited attention has been paid to the environmental threat caused by the release of acidity and heavy metals to the surrounding water courses. Even less attention is paid on release of major nutrients, such as nitrogen, although these sediments are extremely rich in carbon and nitrogen and present a potentially high microbiological activity. In Europe, the largest cover of acid sulfate soils is found in coastal lowlands of Finland. Estimates of acid sulfate soils in agricultural use range from 1 300 to 3 000 km2, but the area in other land use classes, such as managed peatland forests, is presumably larger. In Finland, 49 500 km2 of peatlands have been drained for forestry, and most of these peatland forests will be at the regeneration stage within 10 to 30 years. As ditch network maintenance is often a prerequisite for a successful establishment of the following tree generation, the effects of maintenance operations on the quality of drainage water should be under special control in peatlands underlain by sulfide-bearing sediments. Therefore, identification of risk areas and effective prevention of acidity and metal release during drain maintenance related soil excavating are great challenges for forestry on coastal lowlands of Finland. The organic and inorganic nitrogen

  15. [Soil quality assessment of forest stand in different plantation esosystems].

    PubMed

    Huang, Yu; Wang, Silong; Feng, Zongwei; Gao, Hong; Wang, Qingkui; Hu, Yalin; Yan, Shaokui

    2004-12-01

    After a clear-cutting of the first generation Cunninghamia lanceolata plantation in 1982, three plantation ecosystems, pure Michelia macclurei stand (PMS), pure Chinese-fir stand (PCS) and their mixed stand, were established in spring 1983, and their effects on soil characteristics were evaluated by measuring some soil physical, chemical, microbiological and biochemical parameters. After 20 years' plantation, all test indices showed differences among different forest management models. Both PMS and MCM had a favorable effect on soil fertility maintenance. Soil quality assessment showed that some soil functions, e.g., water availability, nutrient availability, root suitability and soil quality index were all in a moderate level under the mixed and pure PMS stands, whereas in a relatively lower level under successive PCS stand. The results also showed that there existed close correlations between soil total organic C (TOC), cation exchange capacity (CEC), microbial biomass-C (Cmic) and other soil physical, chemical and biological indices. Therefore, TOC, CEC and Cmic could be used as the indicators in assessing soil quality in this study area. In addition, there were also positive correlations between soil microbial biomass-C and TOC, soil microbial biomass-N and total N, and soil microbial biomass-P and total P in the present study. PMID:15825426

  16. Changes in Soil Nitrogen Storage and Dynamics in Response to Forest Management in Southeastern Pine Forest

    NASA Astrophysics Data System (ADS)

    Boutton, T. W.; Foote, J. A.; Scott, D. A.

    2013-12-01

    Forest harvesting increases radiation reaching the soil surface, decreases transpiration and rainfall interception, and increases the amount of precipitation reaching and infiltrating into the soil. The magnitude of these impacts varies with intensity of tree harvest method, but generally results in warmer, moister soils that favor microbial activity and accelerate N cycling processes that can result in leaching and gaseous N losses from the ecosystem. More intense forest harvest (i.e., removal of increasing amounts of aboveground biomass) results in greater N losses, potentially limiting the productivity and sustainability of future rotations. This study determined the impact of forest harvest intensity, soil compaction, and their interaction on N-cycling in a loblolly pine (Pinus taeda L.) forest 15-years following treatment. We quantified N and δ15N in litter, root, and soil compartments at the Long Term Soil Productivity Experiment in Crockett National Forest in eastern Texas. Treatment plots of 0.4 ha were established in 1997 and consisted of three harvest methods (bole only, whole tree, and whole tree + forest floor removal) in factorial combination with three levels of soil compaction (none, intermediate, and severe); all treatment combinations were replicated (n=3). Sampling was conducted quarterly from March 2011 through March 2012. Litter N pool sizes were reduced significantly by increasing harvest intensity and varied significantly through time. Litter N was highest in the bole only treatment (10-13 g N m-2) and lowest in the whole tree+forest floor removal treatment (9-10 g N m-2). Soil total N storage in the 0-10-cm increment was also reduced significantly by increasing harvest intensity and was highest in the bole only treatment (74-99 g N m-2) and lowest in the whole tree+forest floor removal treatment (61-83 g N m-2). Tree harvest methods had no effect on the total root N pool (fine + coarse roots) in the upper 10 cm of the soil profile; however

  17. Effects of fire on properties of forest soils: a review.

    PubMed

    Certini, Giacomo

    2005-03-01

    Many physical, chemical, mineralogical, and biological soil properties can be affected by forest fires. The effects are chiefly a result of burn severity, which consists of peak temperatures and duration of the fire. Climate, vegetation, and topography of the burnt area control the resilience of the soil system; some fire-induced changes can even be permanent. Low to moderate severity fires, such as most of those prescribed in forest management, promote renovation of the dominant vegetation through elimination of undesired species and transient increase of pH and available nutrients. No irreversible ecosystem change occurs, but the enhancement of hydrophobicity can render the soil less able to soak up water and more prone to erosion. Severe fires, such as wildfires, generally have several negative effects on soil. They cause significant removal of organic matter, deterioration of both structure and porosity, considerable loss of nutrients through volatilisation, ash entrapment in smoke columns, leaching and erosion, and marked alteration of both quantity and specific composition of microbial and soil-dwelling invertebrate communities. However, despite common perceptions, if plants succeed in promptly recolonising the burnt area, the pre-fire level of most properties can be recovered and even enhanced. This work is a review of the up-to-date literature dealing with changes imposed by fires on properties of forest soils. Ecological implications of these changes are described. PMID:15688212

  18. Preliminary assessment of soil erosion impact during forest restoration process

    NASA Astrophysics Data System (ADS)

    Lai, Yen-Jen; Chang, Cheng-Sheng; Tsao, Tsung-Ming; Wey, Tsong-Huei; Chiang, Po-Neng; Wang, Ya-Nan

    2014-05-01

    Taiwan has a fragile geology and steep terrain. The 921 earthquake, Typhoon Toraji, Typhoon Morakot, and the exploitation and use of the woodland by local residents have severely damaged the landscape and posed more severe challenges to the montane ecosystem. A land conservation project has been implemented by the Experimental Forest of National Taiwan University which reclaimed approximately 1,500 hectares of leased woodland from 2008 to 2010, primarily used to grow bamboo, tea trees, betel nut, fruit, and vegetable and about 1,298 hectares have been reforested. The process of forest restoration involves clear cutting, soil preparation and a six-year weeding and tending period which may affect the amount of soil erosion dramatically. This study tried to assess the impact of forest restoration from the perspective of soil erosion through leased-land recovery periods and would like to benefit the practical implementation of reforestation in the future. A new plantation reforested in the early 2013 and a nearby 29-year-old mature forest were chosen as experimental and comparison sites. A self-designed weir was set up in a small watershed of each site for the runoff and sediment yield observation. According to the observed results from May to August 2013, a raining season in Taiwan, the runoff and erosion would not as high as we expected, because the in-situ soil texture of both sites is sandy loam to sandy with high percentage of coarse fragment which increased the infiltration. There were around 200 kg to 250 kg of wet sand/soil yielded in mature forest during the hit of Typhoon Soulik while the rest of the time only suspended material be yielded at both sites. To further investigate the influence of the six-year weeding and tending period, long term observations are needed for a more completed assessment of soil erosion impact.

  19. Detection of presumptive mycoparasites associated with Entomophaga maimaiga resting spores in forest soils.

    PubMed

    Castrillo, Louela A; Hajek, Ann E

    2015-01-01

    The fungal pathogen Entomophaga maimaiga can provide high levels of control of the gypsy moth, Lymantria dispar, an important forest defoliator. This fungus persists in the soil as resting spores and occurs naturally throughout many areas where gypsy moth is established. Studies on the spatial dynamics of gypsy moth population have shown high variability in infection levels, and one possible biological factor could be the variable persistence of E. maimaiga resting spores in the soil due to attacks by mycoparasites. We surveyed presumptive mycoparasites associated with parasitized E. maimaiga resting spores using baiting and molecular techniques and identified an ascomycete (Pochonia sp.) and oomycetes (Pythium spp.). PMID:25433313

  20. The influence of forest regrowth on soil permeability in the humid tropics

    NASA Astrophysics Data System (ADS)

    Hassler, Sibylle; Zimmermann, Beate; Elsenbeer, Helmut

    2010-05-01

    The humid tropics are subject to change in land use: on the one hand ongoing deforestation claims more area for agriculture and pastures, on the other hand reforestation efforts emerge. These changes in land use affect soil hydrological properties. Various studies have shown that a shift from primary forest to pasture leads to a rapid decrease in soil saturated hydraulic conductivity (Ks) through animal treading, implicitly enhancing the occurrence of overland flow. Recent information about the reverse process, the possible recovery of soil hydraulic properties during forest regrowth, suggests a slow recovery of Ks. To further explore this possibility with the help of a space-for-time substitution approach we surveyed Ks in the Panama Canal Zone. In a completely randomised sampling design we sampled several plots of four different land use classes: Pasture, secondary forest of two age classes (5-8 years and 12-15 years after pasture abandonment), and old-growth forest. Undisturbed soil cores were taken from the depths 0-6 and 6-12 cm and then subjected to the constant-head method. We also surveyed bulk density, soil organic carbon, soil texture and vegetation parameters (eg. basal area, diameter at breast height) to help interpret the observed Ks data. Our results support the notion of a slow recovery as they exhibit an increase in Ks after more than 10 years, if only for the depth of 0-6 cm. Other studies suggest that the decrease of Ks after deforestation is limited to a distinct shallow soil layer, thus the observed recovery effect in the upper layer is in logical accordance with these findings. We will use the ancillary information to elucidate the main determinants of Ks recovery. Quantification of the hydrological relevance of these findings is especially important as land use effects are obviously limited to only the upper soil layer. To evaluate the hydrological relevance we will compare the Ks measurements with prevailing rainfall intensities and data of

  1. 137Cs in the fungal compartment of Swedish forest soils.

    PubMed

    Vinichuk, Mykhaylo M; Johanson, Karl J; Taylor, Andy F S

    2004-05-01

    The (137)Cs activities in soil profiles and in the mycelia of four ectomycorrhizal fungi were studied in a Swedish forest in an attempt to understand the mechanisms governing the transfer and retention of (137)Cs in forest soil. The biomass of four species of fungi was determined and estimated to be 16 g m(-2) in a peat soil and 47-189 g m(-2) in non-peat soil to the depth of 10 cm. The vertical distribution was rather homogeneous for two species (Tylospora spp. and Piloderma fallax) and very superficial for Hydnellum peckii. Most of the (137)Cs activity in mycelium of non-peat soils was found in the upper 5 cm. Transfer factors were quite high even for those species producing resupinate sporocarps. In the peat soil only approximately 0.3% of the total (137)Cs inventory in soil was found in the fungal mycelium. The corresponding values for non-peat soil were 1.3, 1.8 and 1.9%. PMID:15081731

  2. Exotic Earthworm Influence on Nitrogen Cycling in FACE Forest Soils

    NASA Astrophysics Data System (ADS)

    Top, S. M.; Filley, T. R.

    2010-12-01

    Exotic earthworm invasion in northern North American forests has the potential to significantly alter nitrogen and carbon cycling in forest soils, through litter layer losses, loss of organic horizon, and changes in fine root density. Earthworm influence on nitrogen cycling is currently being investigated in the free-air CO2 enrichment (FACE) sites at Rhinelander, WI. Because of the 13C depleted CO2 used in the FACE experiment and a 15N addition to the soil, this system affords an ideal opportunity to determine the impact of earthworm activity on soil organic matter dynamics by tracking the relative abundance and stable isotope compositions of biopolymers (amino acids, etc.) isolated in earthworms fecal pellets and soils. The 15N and 13C isotope composition of earthworm fecal matter from epigeic (litter and organic matter horizon dwelling) and endogeic (predominantly mineral soil dwelling) species highlighted their distinct role in litter, surface soil, and deeper soil movement through the soil. Specifically, endogeic fecal matter exhibited a lower uptake of FACE-derived C and a more enriched 15N signal. Nitrogen content of soil between the control and elevated CO2 treatments is not significantly different; however, elevated CO2 treatments exhibited relative depletion in both the soil and root 15N with respect to controls. The loss of 15N in the roots and the top 5 cm of the soil under elevated CO2, suggests that there is greater cycling power with increased below ground productivity and earthworm activity under elevated CO2, as higher abundances of earthworms exist in the elevated CO2 treatments. Amino acid extractions from the soil and fecal matter are ongoing and will help clarify the details regarding molecular nitrogen cycling.

  3. Agricultural and forest resource surveys from space

    NASA Technical Reports Server (NTRS)

    Hoffer, R. M.

    1973-01-01

    An overview is presented on the use of spaceborne remote sensors as aid to agriculture and forestry for soil mapping, crop yield predictions, acreage determinations, damage assessment, and numerous other benefits. Some results obtained by ERTS 1 are discussed in terms of the significance of information derived and the potential use of these data for better management of our natural resources.

  4. Spatial variability of the dehydrogenase activity in forest soils

    NASA Astrophysics Data System (ADS)

    Błońska, Ewa; Lasota, Jarosław

    2014-05-01

    The aim of this study was to assess the spatial variability of the dehydrogenase activity (DH) in forest soils using geostatistics. We have studied variability soil dehydrogenase and their relationship with variability of some physic-chemical properties. Two study areas (A and B) were set up in southern Poland in the Zlotoryja Forest District. Study areas were covered by different types of vegetation (A- broadleaf forest with beech, ash and sycamore), B- coniferous forest with Norway spruce). The soils were classified as Dystric Cambisols (WRB 2006). The samples for laboratory testing were collected from 49 places on each areas. 15 cm of surface horizon of soil were taken (with previously removed litter). Dehydrogenase activity was marked with Lenhard's method according to the Casida procedure. Soil pH, nitrogen (N) and soil organic carbon (C) content (by LECO CNS 2000 carbon analyzer) was marked. C/N ratio was calculated. Particle size composition was determined using laser diffraction. Statistical analysis were performed using STATISTICA 10 software. Geostatistical analysis and mapping were done by application of GS 9+ (Gamma Design) and Surfer 11 (Golden Software). The activity of DH ranged between 5,02 and 71,20 mg TPP• kg-1 •24 h-1 on the A area and between 0,94 and 16,47 mg TPP• kg-1 •24 h-1. Differences in spatial variability of the analised features were noted. The variability of dehydrogenase activity on the A study area was described by an exponential model, whereas on the B study area the spatial correlation has not been noted. The relationship of dehydrogenase activity with the remaining parameters of soil was noted only in the case of A study area. The variability of organic carbon content on the A and B study areas were described by an exponential model. The variability of nitrogen content on both areas were described by an spherical model.

  5. Use of multispectral data in design of forest sample surveys

    NASA Technical Reports Server (NTRS)

    Titus, S. J.; Wensel, L. C.

    1977-01-01

    The use of multispectral data in design of forest sample surveys using a computer software package, WILLIAM, is described. The system allows evaluation of a number of alternative sampling systems and, with appropriate cost data, estimates the implementation cost for each.

  6. Quantifying soil and critical zone variability in a forested catchment through digital soil mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying catchment scale soil property variation yields insights into critical zone evolution and function. The objective of this study was to quantify and predict the spatial distribution of soil properties within a high elevation forested catchment in southern AZ, USA using a combined set of di...

  7. Soil erosion survey using remote sensing images

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Kertész, Ádám; Madarász, Balázs; Pálinkás, Melinda; Tóth, Adrienn

    2016-04-01

    Soil erosion is one of the most effective soil degradation processes reducing crop production on arable fields significantly. It also leads to serious environmental hazards such as eutrophication, mud and flesh floods. Beyond the processes there is an urgent need to survey and descript the current degree of erosion of arable lands in order to provide adequate land use techniques and mitigate the harmful effects. Surveying soil erosion is a very time consuming process since soil loss and deposition take place next to each other resulting a rather diverse erosion pattern even within a plot. Remote sensing is a possible way to determine the degree of soil erosion without special efforts taken in the field. The application of images can provide high resolution erosion maps of almost any type of arable fields. The method is based on the identification of the origin of the surface soil layer, i.e. whether it represents an originally deeper laying horizon (e.g. B horizon), or the parent material. A case study was carried out on a Cambisol formed on loess parent material. The soil and the parent rock have various reflectance spectra in the visible range, so this strip was used for the investigations. For map creation "training sites" were used in ArcMap environment. The obtained results suggest that the method is highly effective and useful, however, other properties like moisture content and plant cover can limit automated application. In this case new training sites are needed. The study was supported by the National Research, Development and Innovation Office (NKFIH),), project Nr. 108755 and the support is gratefully acknowledged here. G. Jakab was supported by the János Bolyai Fellowship.

  8. Does drought alter hydrological functions in forest soils?

    NASA Astrophysics Data System (ADS)

    Gimbel, Katharina; Puhlmann, Heike; Weiler, Markus

    2014-05-01

    Climate change will probably alter precipitation patterns across central Europe, and (summer) droughts are expected to be more frequent and severe in future. Droughts may modify soil properties, such as the pore volume distribution, soil aggregation, water repellency and rooting patterns. These changes in soil properties affect the hydrological functioning of the soil like water retention, infiltration and percolation and thereby the site conditions for plants. The aim of this research is to investigate the effect of droughts on the hydrological functioning of forest soils. We conducted rainfall-reduction experiments in three woodlands (nine investigation sites) across Germany. We established adaptive roofing systems which allow a flexible reduction of the precipitation between 15 % and 65 % of the incoming precipitation depending on the actual precipitation. The impact of the imposed droughts on the soil properties was assessed by repeated analyses of soil aggregation, hydrophobicity and pore volume distribution. Hydrological functioning of the soil was assessed by means of repeated dye tracer sprinkling experiments. Comparing dye tracer images of 2011 with images taken after two years of imposed drought, we found a general shift in infiltration processes depending on the soil type. Sandy soils showed a shift from front-like infiltration towards a more fingered and scattered infiltration. Soils rich in clay tend to develop unstained (= not wetted) areas in the top layer, which might hint to evolving hydrophobicity. This was confirmed by field and laboratory hydrophobicity tests. Further, the same profiles were showing signs of lower permeability in the bottom layers. Similar to hydrophobicity, we want to link the results of soil aggregation and pore volume distribution to the changes in the infiltration pattern. Our study shows that changes in precipitation pattern can severely affect forest soil properties and their hydrological functions. The results of this

  9. Identification of Phytophthora species baited and isolated from forest soil and streams in northwestern Yunnan province, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora species were surveyed by collecting soil samples and placing bait leaves in selected streams during June - October in the years 2005, 2006 and 2010 at three sites in oak forests in Diqing Tibetan Autonomous Prefecture of NW Yunnan province, China. Seventy-three isolates of Phytophthora ...

  10. Fertility of soils under spruce forests of the Khibiny Mountains

    NASA Astrophysics Data System (ADS)

    Orlova, M. A.; Lukina, N. V.; Smirnov, V. E.; Krasnov, D. A.; Kamaev, I. O.

    2012-06-01

    The development of fertility of soils on different parent rocks is considered for different types of spruce forests in the Khibiny Mountains. The spruce forests of Mts. Kuel'por, Vud'yavrchorr, Chil'mana, and Saami were the objects for the study. The results showed that the fertility level of the soils of the Khibiny Mountains was determined by the combined influence of the parent rock's composition and the vegetation. The differences in the soil properties are mainly explained by the composition of the parent rocks. The pod-burs differ from the podzols by the higher contents of organic matter, nitrogen, and available nutrients. The podzols are the most acid soils there. The podburs of Mt Kuel'por developing on base-rich parent rocks are the most fertile. The differences in the fertility of the soils on the intrabiogeocenotic (tessera) level are related to the vegetation. The soils of the spruce and tall-grass tesseras are richer in nitrogen, calcium, and manganese as compared to the soils of the dwarf shrub-green moss, low-grass-dwarf shrub-green moss, and tussock grass-dwarf shrub tesseras.

  11. Urbanization in China drives soil acidification of Pinus massoniana forests

    NASA Astrophysics Data System (ADS)

    Huang, Juan; Zhang, Wei; Mo, Jiangming; Wang, Shizhong; Liu, Juxiu; Chen, Hao

    2015-09-01

    Soil acidification instead of alkalization has become a new environmental issue caused by urbanization. However, it remains unclear the characters and main contributors of this acidification. We investigated the effects of an urbanization gradient on soil acidity of Pinus massoniana forests in Pearl River Delta, South China. The soil pH of pine forests at 20-cm depth had significantly positive linear correlations with the distance from the urban core of Guangzhou. Soil pH reduced by 0.44 unit at the 0-10 cm layer in urbanized areas compared to that in non-urbanized areas. Nitrogen deposition, mean annual temperature and mean annual precipitation were key factors influencing soil acidification based on a principal component analysis. Nitrogen deposition showed significant linear relationships with soil pH at the 0-10 cm (for ammonium N (-N), P < 0.05 for nitrate N (-N), P < 0.01) and 10-20 cm (for -N, P < 0.05) layers. However, there was no significant loss of exchangeable non-acidic cations along the urbanization gradient, instead their levels were higher in urban than in urban/suburban area at the 0-10 cm layer. Our results suggested N deposition particularly under the climate of high temperature and rainfall, greatly contributed to a significant soil acidification occurred in the urbanized environment.

  12. Urbanization in China drives soil acidification of Pinus massoniana forests.

    PubMed

    Huang, Juan; Zhang, Wei; Mo, Jiangming; Wang, Shizhong; Liu, Juxiu; Chen, Hao

    2015-01-01

    Soil acidification instead of alkalization has become a new environmental issue caused by urbanization. However, it remains unclear the characters and main contributors of this acidification. We investigated the effects of an urbanization gradient on soil acidity of Pinus massoniana forests in Pearl River Delta, South China. The soil pH of pine forests at 20-cm depth had significantly positive linear correlations with the distance from the urban core of Guangzhou. Soil pH reduced by 0.44 unit at the 0-10 cm layer in urbanized areas compared to that in non-urbanized areas. Nitrogen deposition, mean annual temperature and mean annual precipitation were key factors influencing soil acidification based on a principal component analysis. Nitrogen deposition showed significant linear relationships with soil pH at the 0-10 cm (for ammonium N(NH4+(-N)), P < 0.05; for nitrate N(NO3-(-N)), P < 0.01) and 10-20 cm (for NO3-(-N), P < 0.05) layers. However, there was no significant loss of exchangeable non-acidic cations along the urbanization gradient, instead their levels were higher in urban than in urban/suburban area at the 0-10 cm layer. Our results suggested N deposition particularly under the climate of high temperature and rainfall, greatly contributed to a significant soil acidification occurred in the urbanized environment. PMID:26400019

  13. Urbanization in China drives soil acidification of Pinus massoniana forests

    PubMed Central

    Huang, Juan; Zhang, Wei; Mo, Jiangming; Wang, Shizhong; Liu, Juxiu; Chen, Hao

    2015-01-01

    Soil acidification instead of alkalization has become a new environmental issue caused by urbanization. However, it remains unclear the characters and main contributors of this acidification. We investigated the effects of an urbanization gradient on soil acidity of Pinus massoniana forests in Pearl River Delta, South China. The soil pH of pine forests at 20-cm depth had significantly positive linear correlations with the distance from the urban core of Guangzhou. Soil pH reduced by 0.44 unit at the 0–10 cm layer in urbanized areas compared to that in non-urbanized areas. Nitrogen deposition, mean annual temperature and mean annual precipitation were key factors influencing soil acidification based on a principal component analysis. Nitrogen deposition showed significant linear relationships with soil pH at the 0–10 cm (for ammonium N (-N), P < 0.05; for nitrate N (-N), P < 0.01) and 10–20 cm (for -N, P < 0.05) layers. However, there was no significant loss of exchangeable non-acidic cations along the urbanization gradient, instead their levels were higher in urban than in urban/suburban area at the 0–10 cm layer. Our results suggested N deposition particularly under the climate of high temperature and rainfall, greatly contributed to a significant soil acidification occurred in the urbanized environment. PMID:26400019

  14. Soil moisture sensitivity of autotrophic and heterotrophic forest floor respiration in boreal xeric pine and mesic spruce forests

    NASA Astrophysics Data System (ADS)

    Ťupek, Boris; Launiainen, Samuli; Peltoniemi, Mikko; Heikkinen, Jukka; Lehtonen, Aleksi

    2016-04-01

    Litter decomposition rates of the most process based soil carbon models affected by environmental conditions are linked with soil heterotrophic CO2 emissions and serve for estimating soil carbon sequestration; thus due to the mass balance equation the variation in measured litter inputs and measured heterotrophic soil CO2 effluxes should indicate soil carbon stock changes, needed by soil carbon management for mitigation of anthropogenic CO2 emissions, if sensitivity functions of the applied model suit to the environmental conditions e.g. soil temperature and moisture. We evaluated the response forms of autotrophic and heterotrophic forest floor respiration to soil temperature and moisture in four boreal forest sites of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) by a soil trenching experiment during year 2015 in southern Finland. As expected both autotrophic and heterotrophic forest floor respiration components were primarily controlled by soil temperature and exponential regression models generally explained more than 90% of the variance. Soil moisture regression models on average explained less than 10% of the variance and the response forms varied between Gaussian for the autotrophic forest floor respiration component and linear for the heterotrophic forest floor respiration component. Although the percentage of explained variance of soil heterotrophic respiration by the soil moisture was small, the observed reduction of CO2 emissions with higher moisture levels suggested that soil moisture response of soil carbon models not accounting for the reduction due to excessive moisture should be re-evaluated in order to estimate right levels of soil carbon stock changes. Our further study will include evaluation of process based soil carbon models by the annual heterotrophic respiration and soil carbon stocks.

  15. Soil organic matter cycling in novel and natural boreal forest ecosystems

    NASA Astrophysics Data System (ADS)

    Norris, C. E.; Mercier Quideau, S.

    2013-12-01

    The uplands of the western boreal forest of Canada are characterized by a mosaic of pure and mixed stands of aspen (Populus tremuloides Michx.) and spruce (Picea glauca (Moench) Voss). In addition to natural ecosystems, the region is now home to novel ecosystems; i.e., ecosystems composed of reclaimed stands formed from trees planted on constructed anthropogenic soils. To understand potential differences in functioning of these novel ecosystems, we must first better understand the functioning of their natural counterparts. Here we present results on both the characterization and cycling of soil organic matter in novel and natural ecosystems found in the Athabasca oil sands region. Soil organic matter from 42 long term monitoring sites was evaluated for long chain (≥ C21) n-alkane composition. The survey showed that n-alkanes were more concentrated and had distinct signatures in natural compared to novel ecosystems. Mineral soils from reclaimed stands showed a distinct microbial community structure from natural aspen and spruce stands, as was demonstrated using phospholipid fatty acids (PLFAs) as microbial biomarkers following addition of 13C-glucose in a laboratory incubation. Further probing by compound specific analysis of the 13C-enriched PLFAs determined that microbial incorporation of 13C-glucose was different among soils. In a field incubation using 15N labeled aspen litter added to the forest floor of reclaimed, harvested and mature natural aspen stands, the microbial community readily incorporated the tracer and nitrogen was cycled to the above-ground vegetation on all sites. In addition, the amendment of leaf litter to the forest floor also increased soil moisture and soil microbial biomass on both the reclaimed and harvested sites. Utilizing stable isotope tracers in addition to a multi-faceted experimental approach has provided insightful results on the development of soil biogeochemical cycling in novel ecosystems.

  16. Phylogenetic analysis on the soil bacteria distributed in karst forest

    PubMed Central

    Zhou, JunPei; Huang, Ying; Mo, MingHe

    2009-01-01

    Phylogenetic composition of bacterial community in soil of a karst forest was analyzed by culture-independent molecular approach. The bacterial 16S rRNA gene was amplified directly from soil DNA and cloned to generate a library. After screening the clone library by RFLP, 16S rRNA genes of representative clones were sequenced and the bacterial community was analyzed phylogenetically. The 16S rRNA gene inserts of 190 clones randomly selected were analyzed by RFLP and generated 126 different RFLP types. After sequencing, 126 non-chimeric sequences were obtained, generating 113 phylotypes. Phylogenetic analysis revealed that the bacteria distributed in soil of the karst forest included the members assigning into Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi (Green nonsulfur bacteria), Bacteroidetes, Verrucomicrobia, Nitrospirae, Actinobacteria (High G+C Gram-positive bacteria), Firmicutes (Low G+C Gram-positive bacteria) and candidate divisions (including the SPAM and GN08). PMID:24031430

  17. Technology and research needs to support soil change studies in reserach and soil survey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil survey products must evolve to address the effects of management practices on the soil resource. There is a rising demand by soil survey customers interested in sustainable use of natural resources for information about land-use impacts on soil quality, ecological processes, and soil function. ...

  18. Soil sustainability study in Lithuanian alien forest stands

    NASA Astrophysics Data System (ADS)

    Čiuldiene, Dovile; Skridlaite, Grazina; Žalūdiene, Gaile; Askelsson, Cecilia; Armolaitis, Kestutis

    2016-04-01

    Tree species are shifting their natural ranges in response to climate changes (Saltré et al., 2013). Northern red oak has originated from North America, but was planted in Europe already in twentieth century. At present, it is considered as invasive species in Poland and at invasive stage in the Lithuanian forests (Riepsas and Straigyte, 2008). European larch naturally grows in Central Europe, but its range has been extended by planting it as far as the Nordic countries. According to a pollen study in peat soils, European larch naturally grew in Lithuania in the sixteenth century and was reintroduced 200 years ago (Jankauskas, 1954). Therefore, the global warming could accelerate the expansion of European larch and Northern red oak into Lithuanian forests. An urgent need appeared to evaluate an impact of those warmth-tolerant species on soil mineral chemistry and quality. New results on the determination of mineral weathering rates in alien forest stands using a PROFILE soil chemistry model were obtained during a doctoral study at the Institute of Forestry. Soil minerals were studied by a Scanning Electron Microscopy at the Institute of Geology and Geography. The results provided a lot of new information on soil weathering rates in Lithuania. The 47 and 157-year-old European larch (Larix decidua Mill.), 45 and 55-year-old Northern red oak (Quercus rubra L.) plantations and adjacent perennial grasslands were chosen for this study. The soils were classified as Luvisols and were developed from glaciofluvial deposits. The PROFILE model requires data of climate conditions (mean annual temperature and precipitation), chemical parameters of atmospheric deposition, forest plantation dendrometric and chemical (wood, foliage litter fall) characteristics, soil physical characteristics and mineral composition. A cation weathering rate (sum of Ca+Mg+ K) is 30% higher in a soil under the Northern red oak than in adjacent perennial grassland. Meanwhile, cation weathering rates

  19. Soil Biochemical Responses to Nitrogen Addition in a Bamboo Forest

    PubMed Central

    Tu, Li-hua; Chen, Gang; Peng, Yong; Hu, Hong-ling; Hu, Ting-xing; Zhang, Jian; Li, Xian-wei; Liu, Li; Tang, Yi

    2014-01-01

    Many vital ecosystem processes take place in the soils and are greatly affected by the increasing active nitrogen (N) deposition observed globally. Nitrogen deposition generally affects ecosystem processes through the changes in soil biochemical properties such as soil nutrient availability, microbial properties and enzyme activities. In order to evaluate the soil biochemical responses to elevated atmospheric N deposition in bamboo forest ecosystems, a two-year field N addition experiment in a hybrid bamboo (Bambusa pervariabilis × Dendrocalamopsis daii) plantation was conducted. Four levels of N treatment were applied: (1) control (CK, without N added), (2) low-nitrogen (LN, 50 kg N ha−1 year−1), (3) medium-nitrogen (MN, 150 kg N ha−1 year−1), and (4) high-nitrogen (HN, 300 kg N ha−1 year−1). Results indicated that N addition significantly increased the concentrations of NH4+, NO3−, microbial biomass carbon, microbial biomass N, the rates of nitrification and denitrification; significantly decreased soil pH and the concentration of available phosphorus, and had no effect on the total organic carbon and total N concentration in the 0–20 cm soil depth. Nitrogen addition significantly stimulated activities of hydrolytic enzyme that acquiring N (urease) and phosphorus (acid phosphatase) and depressed the oxidative enzymes (phenol oxidase, peroxidase and catalase) activities. Results suggest that (1) this bamboo forest ecosystem is moving towards being limited by P or co-limited by P under elevated N deposition, (2) the expected progressive increases in N deposition may have a potential important effect on forest litter decomposition due to the interaction of inorganic N and oxidative enzyme activities, in such bamboo forests under high levels of ambient N deposition. PMID:25029346

  20. A soil burn severity index for understanding soil-fire relations in tropical forests

    USGS Publications Warehouse

    Jain, T.B.; Gould, W.A.; Graham, R.T.; Pilliod, D.S.; Lentile, L.B.; Gonzalez, G.

    2008-01-01

    Methods for evaluating the impact of fires within tropical forests are needed as fires become more frequent and human populations and demands on forests increase. Short- and long-term fire effects on soils are determined by the prefire, fire, and postfire environments. We placed these components within a fire-disturbance continuum to guide our literature synthesis and develop an integrated soil burn severity index. The soil burn severity index provides a set of indicators that reflect the range of conditions present after a fire. The index consists of seven levels, an unburned level and six other levels that describe a range of postfire soil conditions. We view this index as a tool for understanding the effects of fires on the forest floor, with the realization that as new information is gained, the index may be modified as warranted. ?? Royal Swedish Academy of Sciences 2008.

  1. Pine straw harvesting effects on water content of a forest soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study addresses concerns that harvesting pine straw from forests may decrease timber productivity by accelerating evaporation of soil water. Pine needles that accumulate on the forest floor help to conserve soil moisture, protect the soil surface against erosion, moderate soil temperature, inh...

  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. Plant and soil responses to biosolids application following forest fire.

    PubMed

    Meyer, V F; Redente, E F; Barbarick, K A; Brobst, R B; Paschke, M W; Miller, A L

    2004-01-01

    Soil stability and revegetation is a great concern following forest wildfires. Biosolids application might enhance revegetation efforts and enhance soil stability. In May 1997, we applied Metro Wastewater Reclamation District (Denver, CO, USA) composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to improve soil C and N levels and help establish eight native, seeded grasses. The soils on the site belong to the Sphinx series (sandy-skeletal, mixed, frigid, shallow Typic Ustorthents). Vegetation and soils data were collected for four years following treatment. During the four years following treatment, total plant biomass ranged from approximately 50 to 230 g m(-2) and generally increased with increasing biosolids application. The percentage of bare ground ranged from 4 to 58% and generally decreased with increasing biosolids rate. Higher rates of biosolids application were associated with increased concentrations of N, P, and Zn in tissue of the dominant plant species, streambank wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm) Gould subsp. lanceolatus], relative to the unamended, unfertilized control. At two months following biosolids application (1997), total soil C and N at soil depths of 0 to 7.5, 7.5 to 15, and 15 to 30 cm showed significant (P < 0.05) linear increases (r2 > 0.88) as biosolids rate increased. The surface soil layer also showed this effect one year after application (1998). For Years 2 through 4 (1999-2001) following treatment, soil C and N levels declined but did not show consistent trends. The increase in productivity and cover resulting from the use of biosolids can aid in the rehabilitation of wildfire sites and reduce soil erosion in ecosystems similar to the Buffalo Creek area. PMID:15224923

  4. Forest type affects the coupled relationships of soil C and N mineralization in the temperate forests of northern China

    PubMed Central

    Quan, Quan; Wang, Changhui; He, Nianpeng; Zhang, Zhen; Wen, Xuefa; Su, Hongxin; Wang, Qing; Xue, Jingyue

    2014-01-01

    Decomposition of soil organic matter (SOM) is sensitive to vegetation and climate change. Here, we investigated the influence of changes in forest types on the mineralization of soil carbon (C) and nitrogen (N), and their temperature sensitivity (Q10) and coupling relationships by using a laboratory soil incubation experiments. We sampled soils from four forest types, namely, a primary Quercus liaotungensis forest (QL), Larix principis-rupprechtii plantation (LP), Pinus tabulaeformis plantation (PT), and secondary shrub forest (SS) in temperate northern China. The results showed that soil C and N mineralization differed significantly among forest types. Soil C and N mineralization were closely coupled in all plots, and C:N ratios of mineralized SOM ranged from 2.54 to 4.12. Forest type significantly influenced the Q10 values of soil C and N mineralization. The activation energy (Ea) of soil C and N mineralization was negatively related to the SOM quality index in all forest types. The reverse relationships suggested that the carbon quality-temperature (CQT) hypothesis was simultaneously applicable to soil C and N mineralization. Our findings show that the coupled relationships of soil C and N mineralization can be affected by vegetation change. PMID:25322802

  5. Greenhouse Gas Fluxes from Forested Wetland and Upland Soils

    NASA Astrophysics Data System (ADS)

    Savage, K. E.; Davidson, E. A.

    2015-12-01

    Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the most important greenhouse gases. Soils are the dominant natural source of N2O, and have been shown to be a small sink under N-limited conditions. Wetlands are a significant natural source of CH4, and dry upland soils a natural CH4 sink. Soils release CO2 produced by both autotrophic (root) and heterotrophic (microbial) respiration processes. Variation in soil moisture can be very dynamic, and it is one of the dominant factors controlling soil aeration, and hence the balance between aerobic (predominantly CO2 producing) and anaerobic (both CO2 and CH4 producing) respiration. The production and consumption of N2O is also highly dependent on spatial and temporal variation in soil moisture. Howland forest, ME is a mosaic of well drained upland, wetland and small transitional upland/wetland soils which makes for a unique and challenging environment to measure the effects of soil moisture on the net exchange of these important greenhouse gases. To quantify the flux of CO2, CH4 and N2O from the Howland forest soils, we utilized a previously developed automated chamber system for measuring CO2 efflux (Licor 6252 IRGA) from soils, and configured it to run in-line with a new model quantum cascade laser (QCL) system which measures N2O and CH4 (Aerodyne model QC-TILDAS-CS). This system allowed for simultaneous, high frequency, continuous measurement of all three greenhouse gases. Fourteen sampling chambers were deployed in an upland soil (8), nearby wetland (3) and a transitional upland/wetland (3). Each chamber was measured every 90 minutes. Upland soils were consistent sources of CO2 and sinks for CH4, however the N2O fluxes were transient between sources and sinks. The wetland soils were consistent sources of high CH4 emissions, low CO2 emissions and a consistently small N2O sink. The transitional upland/wetland soil was a consistent source of CO2 but was much more transient between CH4 and N2O sources and

  6. Comparison of the carbon stock in forest soil of sessile oak and beech forests

    NASA Astrophysics Data System (ADS)

    Horváth, Adrienn; Bene, Zsolt; Bidló, András

    2016-04-01

    Forest ecosystems are the most important carbon sinks. The forest soils play an important role in the global carbon cycle, because the global climate change or the increase of atmospheric CO2 level. We do not have enough data about the carbon stock of soils and its change due to human activities, which have similar value to carbon content of biomass. In our investigation we measured the carbon stock of soil in 10 stands of Quercus petraea and Fagus sylvatica. We took a 1.1 m soil column with soil borer and divided to 11 samples each column. The course organic and root residues were moved. After evaluation, we compared our results with other studies and the carbon stock of forests to each other. Naturally, the amount of SOC was the highest in the topsoil layers. However, we found significant difference between forest stands which stayed on the same homogenous bedrock, but very close to each other (e.g. distance was 1 or 2 km). We detected that different forest utilizations and tree species have an effect on the forest carbon as the litter as well (amount, composition). In summary, we found larger amount (99.1 C t/ha on average) of SOC in soil of stands, where sessile oak were the main stand-forming tree species. The amount of carbon was the least in turkey oak-sessile oak stands (85.4 C t/ha on average). We found the highest SOC (118.3 C t/ha) in the most mixed stand (silver lime-beech-red oak). In the future, it will be very important: How does climate change affect the spread of tree species or on carbon storage? Beech is more sensitive, but even sessile oak. These species are expected to replace with turkey oak, which is less sensitive to drought. Thus, it is possible in the future that we can expect to decrease of forest soil carbon stock capacity, which was confirmed by our experiment. Keywords: carbon sequestration, mitigation, Fagus sylvatica, Quercus petraea, litter Acknowledgements: Research is supported by the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU

  7. Soil microclimate monitoring in forested and meadow sites

    NASA Astrophysics Data System (ADS)

    Freyerova, Katerina; Safanda, Jan

    2016-04-01

    It is well known fact that forest microclimate differs from open area microclimate (Geiger 1965). Less attention is paid to soil temperatures and their long-term monitoring. To evaluate and compare these two environments from the soil microclimate point of view, Institute of Geophysics in Prague monitors soil and air temperatures in Bedřichov in the Jizerské Hory Mountains (Czech Republic). The soil temperatures are measured in three depths (20, 50 and 100 cm) in forest (700 m a. s. l.) and meadow (750 m a. s. l.). Air temperatures are measured at 2m height both in forest and meadow. Nowadays, we have more than three years long time series. The most of studies and experiments described in literature are short-term ones (in order of days or weeks). However, from short-term experiments the seasonal behaviour and trends can be hardly identified and conclusions on soil temperature reaction to climatic extremes such as heat waves, drought or freeze cannot be done with confidence. These drawbacks of the short-term experiments are discussed in literature (eg. Morecroft et al. 1998; Renaud et al. 2011). At the same, with progression of the global warming, the expected increasing frequency of climatic extremes will affect the future form of forest vegetation (Von Arx et al. 2012). The soil and air temperature series, both from the forest and meadow sites, are evaluated and interpreted with respect to long term temperature characteristics and seasonal trends. The emphasis is given on the soil temperature responses to extreme climatic situations. We examine variability between the localities and depths and spatial and temporal changes in this variability. This long-term monitoring allows us to better understand and examine the behaviour of the soil temperature in extreme weather situations. Therefore, we hope to contribute to better prediction of future reactions of this specific environments to the climate change. Literature Geiger, R., 1965. The climate near the ground

  8. Control of the U and Th behaviour in forest soils

    NASA Astrophysics Data System (ADS)

    Rihs, Sophie; Gontier, Adrien; Chabaux, François; Pelt, Eric; Turpault, Marie-Pierre

    2015-04-01

    U- and Th-series disequilibria and U, Th, Fe and Al speciation, were measured in several soil profiles from the experimental forest site of Breuil (Morvan, France) in order to address the impact of the vegetation on U and Th nuclides behaviour in soils. Thirty-five years after an experimental clear-felling of the native forest, the soil developed under two replacing mono-specific plantations (Oak and Douglas fir) were therefore compared to the undisturbed native forest soil. The analogous physical and chemical properties of these soils before the replacement were formerly demonstrated. Our results suggest that a shift in the Iron distribution seems to occur under the stand replaced by Oaks, with a significant replacement of Fe-bearing silicates by well crystallized Fe oxides. In contrast, such evolution was not demonstrated in the soils under Douglas fir. The concurrent loss of U and Th from the soils under Oak was tentatively related to the dissolution of Fe-bearing minerals. A mass balance calculation demonstrates that the observed increase in U oxalate-extracted fractions can quantitatively be explained through the entire profiles by a mere dissolution of up to 20% of U-Fe-bearing silicated minerals, without significant re-adsorption onto the amorphous Fe-Al oxides for U. Beside this primary release from Fe-bearing silicate minerals, the mobility of U and Th seems more likely controlled by Al phases rather than Fe oxides in surface layers during further pedogenic processes. Indeed, some of the U- and Th series disequilibria seem to be strongly related to Al dynamic in these layers. This relationship can be seen in the native forest profiles as well as in the replaced profiles, suggesting that this feature is not linked to the cover change. The redistribution of U and Th isotopes through these pedogenic processes therefore rule out the use of U-series for weathering rate determination in shallowest soils layers. In contrast, below 25 cm, the release of U and Th

  9. A conceptual framework: redefining forest soil's critical acid loads under a changing climate.

    PubMed

    McNulty, Steven G; Boggs, Johnny L

    2010-06-01

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  10. Density and pathogenic activity of soil microbes associated with windthrows of temperate deciduous forests in the Allegany national Forest, Pennsylvania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Question/Methods Forest disturbance caused by windthrow events has obvious impacts on forest structure and composition above-ground; however, changes in soil microbial communities are less obvious. Windthrows causing the formation of multiple forest gaps occurred in 2003 throughout the...

  11. Effects of Forest Age on Soil Autotrophic and Heterotrophic Respiration Differ between Evergreen and Deciduous Forests

    PubMed Central

    Wang, Wei; Zeng, Wenjing; Chen, Weile; Yang, Yuanhe; Zeng, Hui

    2013-01-01

    We examined the effects of forest stand age on soil respiration (SR) including the heterotrophic respiration (HR) and autotrophic respiration (AR) of two forest types. We measured soil respiration and partitioned the HR and AR components across three age classes ∼15, ∼25, and ∼35-year-old Pinus sylvestris var. mongolica (Mongolia pine) and Larix principis-rupprechtii (larch) in a forest-steppe ecotone, northern China (June 2006 to October 2009). We analyzed the relationship between seasonal dynamics of SR, HR, AR and soil temperature (ST), soil water content (SWC) and normalized difference vegetation index (NDVI, a plant greenness and net primary productivity indicator). Our results showed that ST and SWC were driving factors for the seasonal dynamics of SR rather than plant greenness, irrespective of stand age and forest type. For ∼15-year-old stands, the seasonal dynamics of both AR and HR were dependent on ST. Higher Q10 of HR compared with AR occurred in larch. However, in Mongolia pine a similar Q10 occurred between HR and AR. With stand age, Q10 of both HR and AR increased in larch. For Mongolia pine, Q10 of HR increased with stand age, but AR showed no significant relationship with ST. As stand age increased, HR was correlated with SWC in Mongolia pine, but for larch AR correlated with SWC. The dependence of AR on NDVI occurred in ∼35-year-old Mongolia pine. Our study demonstrated the importance of separating autotrophic and heterotrophic respiration components of SR when stimulating the response of soil carbon efflux to environmental changes. When estimating the response of autotrophic and heterotrophic respiration to environmental changes, the effect of forest type on age-related trends is required. PMID:24282560

  12. Nitrate formation in acid forest soils from the Adirondacks

    SciTech Connect

    Klein, T.M.; Kreitinger, J.P.; Alexander, M.

    1983-01-01

    Nitrate formation in three forest soils from the Adirondacks region of New York was studied in the laboratory. The organic and surface mineral layers of the soils has pH values ranging from 3.6 to 4.1. Nitrate was formed when the soils were treated with artificial rain at pH 3.5, 4.1, or 5.6. Compared to simulated rain at pH 5.6, simulated rain at pH 3.5 enhanced nitrate formation in one soil and inhibited it in two other soils. The rate of nitrate accumulation was about 10 times higher in the organic horizon than in the mineral horizon, and nitrate formation was not enhanced by ammonium additions. Nitrate formation in soil suspensions was dependent on the amount of soil in the suspension, and none was formed if little soil was present. Ammonium did not enhance nitrate production in the suspensions. It is suggested that nitrate formation in these acid soils is not limited by the ammonium supply. 19 references, 2 figures, 2 tables.

  13. Soil organic matter status in forest soils - possible indicators for climate change induced site shifts

    NASA Astrophysics Data System (ADS)

    Koch, Nadine; Thiele-Bruhn, Sören

    2010-05-01

    The quantity and quality of soil organic matter (SOM) and SOM pools and thus the soil properties related to carbon sequestration and water retention are not constant but exhibit considerable variation through changing climate. In total changes in soil fertility and an increase in plant stress are expected. This is relevant for northwest Europe as well and may have economic and social impacts since functions of forests for wood production, groundwater recharge, soil protection and recreation might be affected. The study is done by comparative investigation of selected sites at four watersheds that represent typical forest stands in the region of Luxembourg and South West Germany. The aim is to identify SOM storage and stability in forest soils and its dependence on site properties and interaction with tree stand conditions. According to state of the art fractionation schemes functional C pools in forest soils and their stabilization mechanisms are investigated. In particular, distribution patterns are determined depending on location, tree stand and climatic conditions. Aim is to identify characteristics of SOM stability through fractionation of SOM according to density, particle size and chemical extractability and their subsequent analytical characterization. So far, reasons about the origin, composition and stabilization mechanisms underlying the different SOM pools are not fully understood. Presented are different patterns of distribution of SOM in relation to land use and site conditions, as well as similarities and differences between the different forest soils and results in addition to passive OM pool, which is mainly responsible for long-term stabilization of carbon in soils. These are aligned with selected general' soil properties such as pH, CEC and texture.

  14. Identification of Heterotrophic Nitrification in a Sierran Forest Soil

    PubMed Central

    Schimel, Joshua P.; Firestone, Mary K.; Killham, Kenneth S.

    1984-01-01

    A potential for heterotrophic nitrification was identified in soil from a mature conifer forest and from a clear-cut site. Potential rates of NO2− production were determined separately from those of NO3− by using acetylene to block autotrophic NH4+ oxidation and chlorate to block NO2− oxidation to NO3− in soil slurries. Rates of NO2− production were similar in soil from the forest and the clear-cut site and were strongly inhibited by acetylene. The rate of NO3− production was much greater than that of NO2− production, and NO3− production was not significantly affected by acetylene or chlorate. Nitrate production was partially inhibited by cycloheximide, but was not significantly reduced by streptomycin. Neither the addition of ammonium nor the addition of peptone stimulated NO3− production. 15N labeling of the NH4+ pool demonstrated that NO3− was not coming from NH4+. The potential for heterotrophic nitrification in these forest soils was greater than that for autotrophic nitrification. PMID:16346646

  15. Tropical forest soil microbial communities couple iron and carbon biogeochemistry

    SciTech Connect

    Dubinsky, E.A.; Silver, W.L.; Firestone, M.K.

    2009-10-15

    We report that iron-reducing bacteria are primary mediators of anaerobic carbon oxidation in upland tropical soils spanning a rainfall gradient (3500 - 5000 mm yr-1) in northeast Puerto Rico. The abundant rainfall and high net primary productivity of these tropical forests provide optimal soil habitat for iron-reducing and iron-oxidizing bacteria. Spatially and temporally dynamic redox conditions make iron-transforming microbial communities central to the belowground carbon cycle in these wet tropical forests. The exceedingly high abundance of iron-reducing bacteria (up to 1.2 x 10{sup 9} cells per gram soil) indicated that they possess extensive metabolic capacity to catalyze the reduction of iron minerals. In soils from the higher rainfall sites, measured rates of ferric iron reduction could account for up to 44 % of organic carbon oxidation. Iron reducers appeared to compete with methanogens when labile carbon availability was limited. We found large numbers of bacteria that oxidize reduced iron at sites with high rates of iron reduction and large numbers of iron-reducers. the coexistence of large populations of ironreducing and iron-oxidizing bacteria is evidence for rapid iron cycling between its reduced and oxidized states, and suggests that mutualistic interactions among these bacteria ultimately fuel organic carbon oxidation and inhibit CH4 production in these upland tropical forests.

  16. Evaporation Dynamics of Moss and Bare Soil in Boreal Forests

    NASA Astrophysics Data System (ADS)

    Dempster, S.; Young, J. M.; Barron, C. G.; Bolton, W. R.

    2013-12-01

    Evaporation dynamics of mosses is a critical process in boreal and arctic systems and represents a key uncertainty in hydrology and climate models. At this point, moss evaporation is not well quantified at the plot or landscape scale. Relative to bare soil or litter evaporation, moss evaporation can be challenging to predict because the water flux is not isolated to the moss surface. Evaporation can originate from nearly 10 cm below the surface. Some mosses can wick moisture from even deeper than 10 cm, which subsequently evaporates. The goal of this study was to use field measurements to quantify the moss evaporation dynamics in a coniferous forest relative to bare ground or litter evaporation dynamics in a deciduous forest in Interior Alaska. Measurements were made in two ecosystem types within the boreal forest of Interior Alaska: a deciduous forest devoid of moss and a coniferous forest with a thick moss layer. A small clear chamber was attached to a LiCor 840 infrared gas analyzer in a closed loop system with a low flow rate. Water fluxes were measured for ~ 90 seconds on each plot in dry and wet soil and moss conditions. Additional measurements included: soil temperature, soil moisture, air temperature, barometric pressure, dew point, relative humidity, and wind speed. Thermal infrared images were also captured in congruence with water flux measurements to determine skin temperature. We found that the moss evaporation rate was over 100% greater than the soil evaporation rate (0.057 g/min vs. 0.024 g/min), and evaporation rates in both systems were most strongly driven by relative humidity and surface temperature. Surface temperature was lower at the birch site than the black spruce site because trees shade the surface beneath the birch. High fluxes associated with high water content were sustained for a longer period of time over the mosses compared to the bare soil. The thermal IR data showed that skin temperature lagged the evaporation flux, such that the

  17. Effects of Conversion from Boreal Forest to Arctic Steppe on Soil Communities and Ecosystem Carbon Pools

    NASA Astrophysics Data System (ADS)

    Han, P. D.; Natali, S.; Schade, J. D.; Zimov, N.; Zimov, S. A.

    2014-12-01

    The end of the Pleistocene marked the extinction of a great variety of arctic megafauna, which, in part, led to the conversion of arctic grasslands to modern Siberian larch forest. This shift may have increased the vulnerability of permafrost to thawing because of changes driven by the vegetation shift; the higher albedo of grassland and low insulation of snow trampled by animals may have decreased soil temperatures and reduced ground thaw in the grassland ecosystem, resulting in protection of organic carbon in thawed soil and permafrost. To test these hypothesized impacts of arctic megafauna, we examined an experimental reintroduction of large mammals in northeast Siberia, initiated in 1988. Pleistocene Park now contains 23 horses, three musk ox, one bison, and several moose in addition to the native fauna. The park is 16 square km with a smaller enclosure (< 1 km) where animals spend most of their time and our study was focused. We measured carbon-pools in forested sites (where scat surveys showed low animal use), and grassy sites (which showed higher use), within the park boundaries. We also measured thaw depth and documented the soil invertebrate communities in each ecosystem. There was a substantial difference in number of invertebrates per kg of organic soil between the forest (600 ± 250) and grassland (300 ± 250), though these differences were not statistically significant they suggest faster nutrient turnover in the forest or a greater proportion of decomposition by invertebrates than other decomposers. While thaw depth was deeper in the grassland (60 ± 4 cm) than in the forest (40 ± 6 cm), we did not detect differences in organic layer depth or percent organic matter between grassland and forest. However, soil in the grassland had higher bulk density, and higher carbon stocks in the organic and mineral soil layers. Although deeper thaw depth in the grassland suggests that more carbon is available to microbial decomposers, ongoing temperature monitoring

  18. SOIL AIR CARBON DIOXIDE CONCENTRATIONS IN A NEW ENGLAND SPRUCE-FIR FORESTS

    EPA Science Inventory

    Research and modeling efforts to evaluate soil-soil solution chemical interactions must take into account solution equilibria with soil air CO2. Measurements of soil air CO2 and soil temperature were made in the major horizons of a forest soil in eastern Maine through the 1985 gr...

  19. Increasing microbial diversity and nitrogen cycling potential of burnt forest soil in Spain through post-fire management

    NASA Astrophysics Data System (ADS)

    Pereg, Lily; Mataix-Solera, Jorge; McMillan, Mary; García-Orenes, Fuensanta

    2016-04-01

    Microbial diversity and function in soils are increasingly assessed by the application of molecular methods such as sequencing and PCR technology. We applied these techniques to study microbial recovery in post-fire forest soils. The recovery of forest ecosystems following severe fire is influenced by post-fire management. The removal of burnt tree stumps (salvage logging) is a common practice in Spain following fire. In some cases, the use of heavy machinery in addition to the vulnerability of soils to erosion and degradation make this management potentially damaging to soil, and therefore to the ecosystem. We hypothesized that tree removal slows down the recovery of soil biological communities including microbial and plant communities and contributes to soil degradation in the burnt affected area. The study area is located in "Sierra de Mariola Natural Park" in Alcoi, Alicante (E Spain). A big forest fire (>500 has) occurred in July 2012. The forest is composed mainly of Pinus halepensis trees with an understory of typical Mediterranean shrubs species such as Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Brachypodium retusum, etc. Soil is classified as a Typic Xerorthent (Soil Survey Staff, 2014) developed over marls. In February 2013, salvage logging (SL) treatment, with a complete extraction of the burned wood using heavy machinery, was applied to a part of the affected forest. Plots for monitoring the effects of SL were installed in this area and in a similar nearby control (C) area, where no SL treatment was done. The recovery of soil bacterial and fungal communities post-fire with and without tree removal was analysed by using Next-Generation sequencing and the abundance of functional genes, related to nitrogen cycling, in the soil was estimated using quantitative PCR (qPCR). We will present the methods used and the results of our study in this PICO presentation.

  20. Reduced deep soil water uptake through forest conversion to pasture in Amazonia

    SciTech Connect

    Jipp, P.H.; Nepstad, D.C. Woods Hole Research Center, MA )

    1993-06-01

    Forests of eastern Amazonia are being replaced by pastures and secondary forests. We measured soil water storage and flux in adjacent forest and pasture ecosystems using Time Domain Reflectometry sensors installed in the walls of deep (9-m) shafts. The forest withdrew 597+/-25 mm of soil water stored below 1 m depth during the 1991 dry season (Jun-Dec), 1.7 times more than the pasture. Uptake from the bottom of the forest soil profile continued even after rainfall resumed in early 1992. The hydrologic impacts of tropical deforestation may be most severe for evergreen forests with deep rooting zones in areas of seasonal drought.

  1. Organic Colloids in Forest Soils: 1. Biochemical Mobilization in the Forest Floor

    NASA Astrophysics Data System (ADS)

    Guggenberger, G.; Kaiser, K.; Zech, W.

    1998-03-01

    Colloid-assisted contaminant transport in soils strongly depends on the concentration, the chemical composition and the charge behavior of the carrier. Organic colloids are produced in significant amounts in the forest canopy and in the forest floor. Besides pure chemical dissolution equilibria biotic processes comprise to the mobilization of organic colloids. 13C NMR spectroscopy and destructive analytical methods applied on solid and colloidal organic matter obtained in the forest floor was used to assess the formation and mobilization pathways of organic colloids. The studies suggested that a major part of the organic solutes are lignocellulose-degradation products being strongly microbially altered in the course of ligninolysis. The release of lignin-derived moieties into the soil solution is directly controlled by their degree of bio-oxidation. Microorganisms contribute also directly to the organic solutes through the release of microbial metabolites. There are indications that the microbial-controlled production of organic colloids in the forest floor is vulnerable to changes in the soil environment.

  2. Rhizosphere activity and methane oxidation in a temperate forest soil

    NASA Astrophysics Data System (ADS)

    Moody, Catherine S.; Subke, Jens-Arne; Voke, Naomi R.; Holden, Robert D.; Ineson, Phil; Arn Teh, Yit

    2010-05-01

    Methane (CH4) concentrations in the Earth's atmosphere have increased dramatically over recent decades. An abundance of studies indicate that the magnitude of natural methane efflux from wetlands is likely to increase due to climate change. However, the role of vegetation and soils in upland methane oxidation are less well understood. Well-aerated soils are known to be sites of methane oxidation, and amongst a range of abiotic environmental parameters, soil moisture has been identified as critical regulator of the methane oxidation rates. However, the role of microbial activity within the soil, particularly C turnover in the plant rhizosphere, has not been investigated as a means for regulating methanotrophy. We combined a continuous soil CO2 efflux system (Li-Cor Biosciences, LI-8100) with a Cavity-Ringdown-Spectroscopy Fast Greenhouse Gas Analyser (Los Gatos Research Inc.) to measure soil CH4 oxidation in a pine forest in NE England. The soil has a shallow organic layer overlaying a well-draining sandy gley soil. Fluxes were measured from three different collar treatments: (1) excluding both root and ectomycorrhizal (EM) hyphae by trenching using deep collars, (2) excluding roots but allowing access by EM hyphae, and (3) unmodified forest soil (i.e. including both roots and EM hyphae). All collars were protected from natural throughfall, and received weekly-averaged amounts of throughfall based on collections in the stand. Data from two months in early summer 2009 indicate that CH4 oxidation in collars with an intact rhizosphere is more than twice that of either of the exclusion treatments (averaging approx. 90 g ha-1 d-1 in that period). We observed higher fluxes when soils were dryer (i.e. with increasing time since watering), indicating a significant influence of moisture. Despite the confounding effects of soil moisture associated with root water uptake in the unmodified soil collars, we argue that rhizosphere activity is an overlooked component in

  3. Effects of Holocene vegetation change on soils across the forest-grassland transition, northern Minnesota, and implications for erosion processes

    NASA Astrophysics Data System (ADS)

    Mason, Joseph; Kasmerchak, Chase; Keita, Hawa; Liang, Mengyu; Gruley, Kristine

    2016-04-01

    Boundaries between forest and grassland in the midlatitudes and their shifts in response to Holocene climatic change, provide opportunities to detect effects of life on landscapes. In northern Minnesota, USA, paleoecological research has documented that grassland and/or savanna expanded eastward in the dry early to middle Holocene. In the late Holocene, forest cover expanded westward at the expense of savanna and grassland. We studied soils at 20 sites spanning the forest-grassland transition. A dramatic change in soil morphology coincides approximately, though not exactly, with that transition as recorded in 1870s-1880s land surveys, suggesting that soils change rapidly in response to forest expansion (we are attempting to constrain the timescale of response through radiocarbon dating of deep soil organic matter in which stable C isotopes record past presence of grassland). The key changes from grassland to forest are loss of organic matter below a thin surface A horizon and greatly enhanced mobility and downward translocation of clay - particularly smectite - in forest soils. This results in upper soil horizons that have relatively low smectite content and low microaggregate stability (as detected through laser diffraction analysis of aggregate disintegration in laboratory experiments), especially below the thin A horizon. The best explanation for this change appears to involve differences in how OM is added to and accumulated in the soil under forest and grassland; soil acidity and base saturation change more gradually eastward along a gradient more likely to reflect climate than vegetation. Evidence of bioturbation (especially gopher burrowing) is much more common at former grassland sites. In addition to mixing OM downward in the soil, burrowing moves detrital carbonates upward, probably enhancing OM accumulation and aggregate stability. Research on geomorphic response to Holocene climatic change in the Midwestern US has often emphasized higher potential

  4. Forest soil chemistry and terrain attributes in a Catskills watershed

    USGS Publications Warehouse

    Johnson, C.E.; Ruiz-Mendez, J. J.; Lawrence, G.B.

    2000-01-01

    Knowledge of soil chemistry is useful in assessing the sensitivity of forested areas to natural and anthropogenic disturbances, but characterizing large areas is expensive because of the large sample numbers required and the cost of soil chemical analyses. We collected and chemically analyzed soil samples from 72 sites within a 214-ha watershed in the Catskill Mountains of New York to evaluate factors that influence soil chemistry and whether terrain features could be used to predict soil chemical properties. Using geographic information system (GIS) techniques, we determined five terrain attributes at each sampling location: (i) slope, (ii) aspect, (iii) elevation, (iv) topographic index, and (v) flow accumulation. These attributes were ineffective in predicting the chemical properties of organic and mineral soil samples; together they explained only 4 to 25% of the variance in pH(w), effective cation-exchange capacity (CEC(e)), exchangeable bases, exchangeable acidity, total C, total N, and C/N ratio. Regressions among soil properties were much better; total C and pH(w) together explained 33 to 66% of the variation in exchangeable bases and CEC(e). Total C was positively correlated with N (r = 0.91 and 0.96 in Oa horizons and mineral soil, respectively), exchangeable bases (r = 0.65, 0.76), and CEC(e) (r = 0.54, 0.44), indicating the importance of organic matter to the chemistry of these acidic soils. The fraction of CEC(e) occupied by H explained 44% of the variation in pH(w). Soil chemical properties at this site vary on spatial scales finer than typical GIS analyses, resulting in relationships with poor predictive power. Thus, interrelationships among soil properties are more reliable for prediction.Knowledge of soil chemistry is useful in assessing the sensitivity of forested areas to natural and anthropogenic disturbances, but characterizing large areas is expensive because of the large sample numbers required and the cost of soil chemical analyses. We

  5. LANDSAT-1 data, its use in a soil survey program

    NASA Technical Reports Server (NTRS)

    Westin, F. C.; Frazee, C. J.

    1975-01-01

    The following applications of LANDSAT imagery were investigated: assistance in recognizing soil survey boundaries, low intensity soil surveys, and preparation of a base map for publishing thematic soils maps. The following characteristics of LANDSAT imagery were tested as they apply to the recognition of soil boundaries in South Dakota and western Minnesota: synoptic views due to the large areas covered, near-orthography and lack of distortion, flexibility of selecting the proper season, data recording in four parts of the spectrum, and the use of computer compatible tapes. A low intensity soil survey of Pennington County, South Dakota was completed in 1974. Low intensity inexpensive soil surveys can provide the data needed to evaluate agricultural land for the remaining counties until detailed soil surveys are completed. In using LANDSAT imagery as a base map for publishing thematic soil maps, the first step was to prepare a mosaic with 20 LANDSAT scenes from several late spring passes in 1973.

  6. Radionuclide behaviour in forest soils of Russian Federation and Ukraine

    NASA Astrophysics Data System (ADS)

    Shcheglov, A. I.; Tsvetnova, O. B.

    2012-04-01

    Behaviour of radionuclides in soil determines to a great extent the radionuclide root uptake and their further migration in food chains. The radionuclide fate in the soil is determined by a wide spectrum of simultaneously running, often competitive elementary processes, such as adsorption-desorption, diffusion-mass transport, retention-migration, etc. The intensity of each elementary process depends, in turn, on a combination of several factors such as nature of the radionuclide, physicochemical features of the fallout, soil properties, environmental regimes, etc. Radionuclide deposition in soils is known to be a basic criterion of the radioecological situation in the contaminated territory. Our long-term investigations performed in contaminated forests (30-km zone of Chernobyl NPP; Tula, Kaluga and Bryansk regions of the Russian Federation) had shown that radionuclide migration in the forest landscapes was determined primarily by the forest litter presence. The key factors of radionuclide redistribution within the soil litter are (i) permanent addition of the low-contaminated organic matter ("clean" litterfall), and (ii) high rate of transformation. The dynamics and intensity of decontamination processes depends on the forest litter sub-horizon. Leaf (A0l) layer exhibits the highest rate of decontamination: 137Cs content in this layer decreased twofold by the second year after the accident and reached its equilibrium value (about 1% of the total deposition) by the 4-5th year after the fallout. The corresponding quasi-equilibrium radionuclide content in A0f layer (10-20%) is reached by the 8-9th year after the accident. The corresponding equilibrium in A0h layer is not reached yet. Thus, the effective half-life of radionuclides in soils should be calculated for each sub-horizon separately, taking into account the above-discussed features of the radionuclide dynamics. The rate of annual radionuclide replacement from the forest litter to mineral layers depends on the

  7. Changes in Forest Soil Properties in Different Successional Stages in Lower Tropical China

    PubMed Central

    Li, Yuelin; Yang, Fangfang; Ou, Yangxu; Zhang, Deqiang; Liu, Juxiu; Chu, Guowei; Zhang, Yaru; Otieno, Dennis; Zhou, Guoyi

    2013-01-01

    Background Natural forest succession often affects soil physical and chemical properties. Selected physical and chemical soil properties were studied in an old-growth forest across a forest successional series in Dinghushan Nature Reserve, Southern China. Methodology/Principal Findings The aim was to assess the effects of forest succession change on soil properties. Soil samples (0–20 cm depth) were collected from three forest types at different succession stages, namely pine (Pinus massoniana) forest (PMF), mixed pine and broadleaf forest (PBMF) and monsoon evergreen broadleaf forest (MEBF), representing early, middle and advanced successional stages respectively. The soil samples were analyzed for soil water storage (SWS), soil organic matter (SOM), soil microbial biomass carbon (SMBC), pH, NH4+-N, available potassium (K), available phosphorus (P) and microelements (available copper (Cu), available zinc (Zn), available iron (Fe) and available boron (B)) between 1999 and 2009. The results showed that SWS, SOM, SMBC, Cu, Zn, Fe and B concentrations were higher in the advanced successional stage (MEBF stage). Conversely, P and pH were lower in the MEBF but higher in the PMF (early successional stage). pH, NH4+-N, P and K declined while SOM, Zn, Cu, Fe and B increased with increasing forest age. Soil pH was lower than 4.5 in the three forest types, indicating that the surface soil was acidic, a stable trend in Dinghushan. Conclusion/Significance These findings demonstrated significant impacts of natural succession in an old-growth forest on the surface soil nutrient properties and organic matter. Changes in soil properties along the forest succession gradient may be a useful index for evaluating the successional stages of the subtropical forests. We caution that our inferences are drawn from a pseudo-replicated chronosequence, as true replicates were difficult to find. Further studies are needed to draw rigorous conclusions regarding on nutrient dynamics in

  8. [Characteristics of macropores in two forest soils on northern slope of Changbai Mountains].

    PubMed

    Li, Wei-li; Jin, Chang-jie; Wang, An-zhi; Pei, Tie-fan; Guan, De-xin

    2007-06-01

    By using dye tracing and image analysis, the characteristics and distribution of macropores in brown coniferous forest soil and dark brown forest soil on northern slope of Changbai Mountains were studied, with the factors affecting the formation of the macropores discussed. The results showed that the vertical distribution pattern of soil macropores could be indirectly known by the variation of dyed area with soil depth. The dyed area of the two soils tended to decrease with increasing soil depth. In 24 hours, the macropore flow transferred 10-20 cm deeper in brown coniferous forest soil than in dark brown forest soil, and there were more macropore flow paths in brown coniferous forest soil. By unit area, brown coniferous forest soil had 6 paths, while dark brown forest soil only had 1 path. The existence of macropore flow could accelerate the infiltration speed by 2 or 3 times at least. Bio-factor was the key factor affecting the formation of macropores in the two kinds of forest soil. There were more macropores formed by soil animals, and the diameter was mostly between 2 and 4 mm. PMID:17763718

  9. Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils.

    PubMed

    VanInsberghe, David; Maas, Kendra R; Cardenas, Erick; Strachan, Cameron R; Hallam, Steven J; Mohn, William W

    2015-11-01

    The genus Bradyrhizobium has served as a model system for studying host-microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbiotic relatives. In addition, we identify fine-scaled differentiation between populations inhabiting neighboring soil layers that illustrate how diversity within Bradyrhizobium is structured by habitat similarity. These findings reconcile incongruent observations about this widely studied and important group of bacteria and highlight the value of ecological context to interpretations of microbial diversity and taxonomy. These results further suggest that the influence of this genus likely extends well beyond facilitating agriculture, especially as forest ecosystems are large and integral components of the biosphere. In addition, this study demonstrates how focusing research on economically important microorganisms can bias our understanding of the natural world. PMID:25909973

  10. Sampling dynamic soil properties and vegetation for soil survey and ecological site descriptions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dynamic soil property data can be collected during soil survey updates to add value to soil survey products and meet users needs for ecological site descriptions. Producers and land managers need information about soil and ecosystem change in order to plan for long-term productivity, conduct monito...

  11. Guidelines for sampling for dynamic soil properties for soil survey updates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dynamic soil property data can be collected during soil survey updates to add value to soil survey products and meet users’ needs. Producers and land managers need information about soil and ecosystem change in order to plan for long-term productivity, conduct monitoring and assessments and predict ...

  12. Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem

    PubMed Central

    You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

    2016-01-01

    Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models. PMID:26925871

  13. Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem

    NASA Astrophysics Data System (ADS)

    You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

    2016-03-01

    Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models.

  14. Increased mercury in forest soils under elevated carbon dioxide

    SciTech Connect

    Natali, Susan M.; Sa_udo-Wilhelmy, Sergio A.; Norby, Richard J; Finzi, Adrien C; Lerdau, Manuel T.

    2008-01-01

    Fossil fuel combustion is the primary anthropogenic source of both CO2 and Hg to the atmosphere. On a global scale, most Hg that enters ecosystems is derived from atmospheric Hg that deposits onto the land surface. Increasing concentrations of atmospheric CO2 may affect Hg deposition to terrestrial systems and storage in soils through CO2-mediated changes in plant and soil properties. We show, using free-air CO2 enrichment (FACE) experiments, that soil Hg concentrations are almost 30% greater under elevated atmospheric CO2 in two temperate forests. There were no direct CO2 effects, however, on litterfall, throughfall or stemflow Hg inputs. Soil Hg was positively correlated with percent soil organic matter (SOM), suggesting that CO2-mediated changes in SOM have influenced soil Hg concentrations. Through its impacts on SOM, elevated atmospheric CO2 may increase the Hg storage capacity of soils and modulate the movement of Hg through the biosphere. Such effects of rising CO2, ones that transcend the typically studied effects on C and nutrient cycling, are an important next phase for research on global environmental change.

  15. Dehydrogenase activity of forest soils depends on the assay used

    NASA Astrophysics Data System (ADS)

    Januszek, Kazimierz; Długa, Joanna; Socha, Jarosław

    2015-01-01

    Dehydrogenases are exclusively intracellular enzymes, which play an important role in the initial stages of oxidation of soil organic matter. One of the most frequently used methods to estimate dehydrogenase activity in soil is based on the use of triphenyltetrazolium chloride as an artificial electron acceptor. The purpose of this study was to compare the activity of dehydrogenases of forest soils with varied physicochemical properties using different triphenyltetrazolium chloride assays. The determination was carried out using the original procedure by Casida et al., a modification of the procedure which involves the use of Ca(OH)2 instead of CaCO3, the Thalmann method, and the assay by Casida et al. without addition of buffer or any salt. Soil dehydrogenase activity depended on the assay used. Dehydrogenase determined by the Casida et al. method without addition of buffer or any salt correlated with the pH values of soils. The autoclaved strongly acidic samples of control soils showed high concentrations of triphenylformazan, probably due to chemical reduction of triphenyltetrazolium chloride. There is, therefore, a need for a sterilization method other than autoclaving, ie a process that results in significant changes in soil properties, thus helping to increase the chemical reduction of triphenyltetrazolium chloride.

  16. Vegetation, soil, and flooding relationships in a blackwater floodplain forest

    USGS Publications Warehouse

    Burke, M.K.; King, S.L.; Gartner, D.; Eisenbies, M.H.

    2003-01-01

    Hydroperiod is considered the primary determinant of plant species distribution in temperate floodplain forests, but most studies have focused on alluvial (sediment-laden) river systems. Few studies have evaluated plant community relationships in blackwater river systems of the South Atlantic Coastal Plain of North America. In this study, we characterized the soils, hydroperiod, and vegetation communities and evaluated relationships between the physical and chemical environment and plant community structure on the floodplain of the Coosawhatchie River, a blackwater river in South Carolina, USA. The soils were similar to previous descriptions of blackwater floodplain soils but had greater soil N and P availability, substantially greater clay content, and lower soil silt content than was previously reported for other blackwater river floodplains. Results of a cluster analysis showed there were five forest communities on the site, and both short-term (4 years) and long-term (50 years) flooding records documented a flooding gradient: water tupelo community > swamp tupelo > laurel oak = overcup oak > mixed oak. The long-term hydrologic record showed that the floodplain has flooded less frequently from 1994 to present than in previous decades. Detrended correspondence analysis of environmental and relative basal area values showed that 27% of the variation in overstory community structure could be explained by the first two axes; however, fitting the species distributions to the DCA axes using Gaussian regression explained 67% of the variation. Axes were correlated with elevation (flooding intensity) and soil characteristics related to rooting volume and cation nutrient availability. Our study suggests that flooding is the major factor affecting community structure, but soil characteristics also may be factors in community structure in blackwater systems. ?? 2003, The Society of Wetland Scientists.

  17. Assessing relationships between forest structure and soil erosion in mountainous forest using a Cesium-137 tracer technique

    NASA Astrophysics Data System (ADS)

    Choi, Kwanghun; Reineking, Björn

    2016-04-01

    The fallout radionuclides (FRNs) particularly Cesium-137 are known as a quantitatively reliable means of estimating sediment redistribution rates within agricultural landscapes and forested area. However, fewer studies have done using FRNs in forested areas even though understanding soil redistribution patterns in mountainous forest areas is one of the important issues for forest management. The objective of this study is to figure out key forest structures affecting soil redistribution rate. In this study, we estimated soil loss and gain rate at 50 points with various forest types and topography in steep mountainous forest area in the Experimental Forest of Kangwon National University in Kangwon Province, South Korea by the Cesium-137 tracing technique. The results show the factors related to the topography such as slope and water accumulation have little effect on soil redistribution rate. The shrub and small tree layer affect more on soil redistribution rate. Additionally, the data shows relatively higher erosion rate in Korean Pine tree plantation area (Pinus koraiensis Sieb. et Zucc.) than semi-natural deciduous and Quercus forests where shrubs and small trees are more prevalent.

  18. Soil Bacterial Community Structure Responses to Precipitation Reduction and Forest Management in Forest Ecosystems across Germany

    PubMed Central

    Felsmann, Katja; Baudis, Mathias; Gimbel, Katharina; Kayler, Zachary E.; Ellerbrock, Ruth; Bruehlheide, Helge; Bruckhoff, Johannes; Welk, Erik; Puhlmann, Heike; Weiler, Markus; Gessler, Arthur; Ulrich, Andreas

    2015-01-01

    Soil microbial communities play an important role in forest ecosystem functioning, but how climate change will affect the community composition and consequently bacterial functions is poorly understood. We assessed the effects of reduced precipitation with the aim of simulating realistic future drought conditions for one growing season on the bacterial community and its relation to soil properties and forest management. We manipulated precipitation in beech and conifer forest plots managed at different levels of intensity in three different regions across Germany. The precipitation reduction decreased soil water content across the growing season by between 2 to 8% depending on plot and region. T-RFLP analysis and pyrosequencing of the 16S rRNA gene were used to study the total soil bacterial community and its active members after six months of precipitation reduction. The effect of reduced precipitation on the total bacterial community structure was negligible while significant effects could be observed for the active bacteria. However, the effect was secondary to the stronger influence of specific soil characteristics across the three regions and management selection of overstorey tree species and their respective understorey vegetation. The impact of reduced precipitation differed between the studied plots; however, we could not determine the particular parameters being able to modify the response of the active bacterial community among plots. We conclude that the moderate drought induced by the precipitation manipulation treatment started to affect the active but not the total bacterial community, which points to an adequate resistance of the soil microbial system over one growing season. PMID:25875835

  19. Changes in soil respiration components and their specific respiration along three successional forests in the subtropics

    DOE PAGESBeta

    Han, Tianfeng; Liu, Juxiu; Wang, Gangsheng; Huang, Wenjuan; Zhou, Guoyi

    2016-01-16

    1.Understanding how soil respiration components change with forest succession is critical for modelling and predicting soil carbon (C) processes and its sequestration below-ground. The specific respiration (a ratio of respiration to biomass) is increasingly being used as an indicator of forest succession conceptually based on Odum's theory of ecosystem development. However, the hypothesis that specific soil respiration declines with forest succession remains largely untested. 2.We used a trenching method to partition soil respiration into heterotrophic respiration and autotrophic respiration (RH and RA) and then evaluated the specific RH and specific RA in three successional forests in subtropical China. 3.Our resultsmore » showed a clear seasonality in the influence of forest succession on RH, with no significant differences among the three forests in the dry season but a higher value in the old-growth forest than the other two forests in the wet season. RA in the old-growth forest tended to be the highest among the three forests. Both the specific RH and specific RA decreased with the progressive maturity of three forests. 4.Lastly, our results highlight the importance of forest succession in determining the variation of RH in different seasons. With forest succession, soil microbes and plant roots become more efficient to conserve C resources, which would result in a greater proportion of C retained in soils.« less

  20. Carbon Stabilization in Wet Tropical Forest Volcanic Soils

    NASA Astrophysics Data System (ADS)

    Marin-Spiotta, E.; Chadwick, O.; Kramer, M.

    2008-12-01

    Volcanic soils, particularly Andisols, have high carbon storage capacities due to the accumulation of highly reactive, non-crystalline minerals. Previous research along a pedogenic chronosequence on volcanic lava in Hawai'i found that soils in the intermediate weathering stage, dominated by allophane, contained the largest soil C stocks with slowest turnover rates. Potential mechanisms for long-term soil C stabilization include an accumulation of chemically recalcitrant C, microenvironmental conditions unfavorable for decomposition, and strong sorption of soluble and otherwise labile C to mineral and/or metals. In well-drained soils in wet climates, dissolved organic matter (DOM) is a likely main pathway for the transport of C from the zones of highest microbial activity to deeper mineral horizons. To address the production, transformation, and fate of dissolved organic matter (DOM), we have installed tension and zero tension lysimeters throughout sequentially deeper organic and mineral horizons in an intermediate aged soil (ca. 350k years) under wet (ca. 3000 mm mean annual rainfall) native tropical forest in Hawai'i. The soils are characterized by thick O horizons and Bh horizons 20-30 cm deep, followed by mineral horizons showing redoximorphic features. Bulk soil carbon to nitrogen ratios increase with soil depth, matching that of DOM in the surface organic horizons at 40-50 cm depth. Low pH does not seem to explain this accumulation of C-rich, N-depleted OM, as soils become less acidic with depth. Soil C:N are positively correlated with alumina, oxalate-extractable Al, and dithionite citrate-extractable Al. The greatest source of DOC is the forest floor (Oie), followed by the Oa horizon, and concentrations decrease significantly in the mineral horizons. DOC concentrations increase with total dissolved Al and Fe in the Oie horizon, and with total Fe in solution in the Bg horizon. In the Bh horizon, DOM C:N are negatively correlated with total Al and Fe in

  1. Soil microbial communities and metabolic function of a Northern Alabama forest ecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thinning, prescribed burning, and their combinations, are common forest management practices to restore degraded forest communities and to prevent uncontrollable wildfires. However, their impacts on soil microbial communities, which are vital to global element cycling, are traditionally overlooked. ...

  2. An Integrated Spatially Dynamic Disturbance and Forest Soil Carbon Model: Preliminary Results from Willow Creek Experimental Forest

    NASA Astrophysics Data System (ADS)

    Scheller, R. M.; Hua, D.; Bolstad, P. V.

    2008-12-01

    Total forest carbon (C) storage is determined by forest succession, multiple interacting disturbances, climate and the edaphic properties of a site or region, including soil texture and depth. How these complex processes interact will determine forest carbon dynamics at landscape and regional scales. We have developed a new succession extension for the LANDIS-II forest landscape simulation model that incorporates the belowground soil C dynamics of the Century soil model. This extension simulates three primary soil organic matter (SOM) pools (fast, slow, passive), litter dynamics, and nitrogen (N) feedbacks to overstory production. The extension was validated against data from the Willow Creek experimental forest in Wisconsin, USA. We subsequently initialized the full model to simulate forest dynamics of 10,000 ha of the surrounding forest landscape. We simulated a representative harvest regime and a historic wind throw regime (50 year wind rotation period, including light, moderate, and extreme events), two common disturbances in mesic forests of the Lake States. We also simulated forest change and total C storage assuming no atmospheric N deposition and N deposition equivalent to 2008 rates. Our results indicate a strong feedback from harvesting to litter C and the fast and slow SOM pools. The passive SOM pool was not significantly altered. Wind disturbance had a negligible effect on all pools. Simulations without N deposition significantly underestimated contemporary forest productivity and the system was more sensitive to disturbances when N deposition was excluded. In conclusion, we have developed a robust model of above and belowground C and N cycling that can readily plug into an existing forest modeling framework to simulate landscape and regional scale forest dynamics and the interactions among forest disturbances, climate change, and soil processes.

  3. Unravelling the importance of forest age stand and forest structure driving microbiological soil properties, enzymatic activities and soil nutrients content in Mediterranean Spanish black pine(Pinus nigra Ar. ssp. salzmannii) Forest.

    PubMed

    Lucas-Borja, M E; Hedo, J; Cerdá, A; Candel-Pérez, D; Viñegla, B

    2016-08-15

    This study aimed to investigate the effects that stand age and forest structure have on microbiological soil properties, enzymatic activities and nutrient content. Thirty forest compartments were randomly selected at the Palancares y Agregados managed forest area (Spain), supporting forest stands of five ages; from 100 to 80years old to compartments with trees that were 19-1years old. Forest area ranging from 80 to 120years old and without forest intervention was selected as the control. We measured different soil enzymatic activities, soil respiration and nutrient content (P, K, Na, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb and Ca) in the top cm of 10 mineral soils in each compartment. Results showed that the lowest forest stand age and the forest structure created by management presented lower values of organic matter, soil moisture, water holding capacity and litterfall and higher values of C/N ratio in comparison with the highest forest stand age and the related forest structure, which generated differences in soil respiration and soil enzyme activities. The forest structure created by no forest management (control plot) presented the highest enzymatic activities, soil respiration, NH4(+) and NO3(-). Results did not show a clear trend in nutrient content comparing all the experimental areas. Finally, the multivariate PCA analysis clearly clustered three differentiated groups: Control plot; from 100 to 40years old and from 39 to 1year old. Our results suggest that the control plot has better soil quality and that extreme forest stand ages (100-80 and 19-1years old) and the associated forest structure generates differences in soil parameters but not in soil nutrient content. PMID:27099995

  4. Acid precipitation and ionic movements in Adironack forest soils

    SciTech Connect

    Mollitor, A.V.; Raynal, D.J.

    1982-01-01

    To examine potential effects of acid precipitation on forest soils in a hardwood and in a coniferous stand in the central Adirondacks of New York State, solution chemistry was studied in five strata of these ecosystems. Bulk precipitation, throughfall, and soil leachates were sampled and analyzed for pH, NO/sub 3/, SO/sub 4/, K, Ca, Mg, and Na. A subset of the samples were analyzed for Al. Organic anion concentrations were estimated from ionic charge balances. Concentrations of NO/sub 3/, H, and K in B horizon leachates were not significantly different than precipitation concentrations, while concentrations of SO/sub 4/, Ca, Mg, and Na in water leaving the sola were significantly greater than precipitation concentrations. Patterns of movement for most ions were similar for both study sites, but concentrations were generally greater in the conifer system. Cation leaching from the hardwood site appears about equally influenced by SO/sub 4/ and organic anion leaching. Sulfate and organic anion concentrations were greater in the conifer site but organic anion leaching dominated. Sulfate appears highly mobile in these soils. Chronic leaching by H/sub 2/SO/sub 4/ combined with internally generated organic acids may represent a threat to the nutrient status of many Adirondack forest soils.

  5. [Effects of climate change on forest soil organic carbon storage: a review].

    PubMed

    Zhou, Xiao-yu; Zhang, Cheng-yi; Guo, Guang-fen

    2010-07-01

    Forest soil organic carbon is an important component of global carbon cycle, and the changes of its accumulation and decomposition directly affect terrestrial ecosystem carbon storage and global carbon balance. Climate change would affect the photosynthesis of forest vegetation and the decomposition and transformation of forest soil organic carbon, and further, affect the storage and dynamics of organic carbon in forest soils. Temperature, precipitation, atmospheric CO2 concentration, and other climatic factors all have important influences on the forest soil organic carbon storage. Understanding the effects of climate change on this storage is helpful to the scientific management of forest carbon sink, and to the feasible options for climate change mitigation. This paper summarized the research progress about the distribution of organic carbon storage in forest soils, and the effects of elevated temperature, precipitation change, and elevated atmospheric CO2 concentration on this storage, with the further research subjects discussed. PMID:20879549

  6. Impact of Nitrogen Fertilization on Soil Organic Matter in Forest Soils (INFOSOM)

    NASA Astrophysics Data System (ADS)

    Forstner, Stefan J.; Tatzber, Michael; Keiblinger, Katharina M.; Schleppi, Patrick; Hagedorn, Frank; Gundersen, Per; Wanek, Wolfgang; Gerzabek, Martin; Zechmeister-Boltenstern, Sohpie

    2014-05-01

    Anthropogenic induced nitrogen (N) deposition has been reported to increase carbon (C) storage in boreal forest soils. However, it is unclear if this also applies to temperate forests where primary production, and hence C inputs to soil, are less limited by N. Likewise, litter decomposition and soil organic matter (SOM) stabilization have been shown to be affected by N inputs, although the exact mechanisms remain unclear. A major obstacle in assessing the net effect of increased N availability on soil C budgets is our limited understanding of the response of soil microorganisms and how this may feedback on SOM stabilization in the long run. To collectively address these questions we make use of two long-time forest N-addition experiments from Klosterhede, Denmark and Alptal, Switzerland which received 50-55 and 25 kg N ha-1 year-1, respectively, for over 20 years. At both sites 15N tracer has been applied with the N-addition treatment enabling isotope-specific analysis. Stands are dominated by Norway spruce (Picea abies) but differ in site characteristics such as soil type, elevation, and mean annual temperature. We investigate the effect of N addition on SOM quantity, quality and depth-distribution using state-of-the-art analytical techniques including isotope ratio mass spectroscopy (IRMS), solid state 13C-NMR, and mid-infrared spectroscopy. Effects on structure and function of soil microbial communities are assessed by standard soil microbiological methods including extracellular enzyme activities and complemented by soil metaproteomics, a rapidly developing novel approach. We hypothesize that long-term N addition will (1) foster the accumulation of soil organic matter (SOM) as well as (2) alter SOM quality and (3) its depth-distribution. Furthermore, N addition will also (4) induce changes in structure and function of microbial communities. First results on N effects on SOM quality and microbial activities in the Ah layer will be presented.

  7. Soil carbon stock and soil characteristics at Tasik Chini Forest Reserve, Pahang, Malaysia

    NASA Astrophysics Data System (ADS)

    Nur Aqlili Riana, R.; Sahibin A., R.

    2015-09-01

    This study was carried out to determine soil carbon stock and soil characteristic at Tasik Chini Forest Reserve (TCFR), Pahang. A total of 10 (20 m x 25 m) permanent sampling plot was selected randomly within the area of TCFR. Soil samples were taken from all subplots using dutch auger based on soil depth of 0-20cm, 20-40cm, 40-60cm. Soil parameters determined were size distribution, soil water content, bulk density, organic matter, organic carbon content, pH and electrical conductivity. All parameters were determined following their respective standard methods. Results obtained showed that the soil in TCFR was dominated by clay texture (40%), followed by sandy clay loam (30%), loam (20%). Silty clay, clay loam and sandy loam constitutes about 10% of the soil texture. Range of mean percentage of organic matter and bulk density are from 2.42±0.06% to 11.64±0.39% and 1.01 to 1.04 (gcm-ł), respectively. Soil pH are relatively very acidic and mean of electrical conductivity is low. Soil carbon content ranged from 0.83±0.03 to 1.87±0.41%. All soil parameter showed a decreasing trend with depth except electrical conductivity. ANOVA test of mean percentage of organic matter, soil water content, soil pH and electrical conductivity showed a significant difference between plot (p<0.05). However there are no significant difference of mean bulk density between plots (p>0.05). There are no significant difference in mean percentage of soil water content, organic matter and bulk density between three different depth (p>0.05). There were a significant difference on percentage of soil carbon organic between plots and depth. The mean of soil organic carbon stock in soil to a depth of 60 cm calculated was 35.50 t/ha.

  8. Recharge forest revisited: soils of Brookhaven National Laboratory

    SciTech Connect

    Grafton, J.

    1980-11-01

    Soil samples were collected from terrestrial systems 44 months after they had been subjected to 22 months of sewage spray application. Data on pH, % organic matter, exchangeable hydrogen, phosphorus, potassium, magnesium, calcium, manganese, iron, aluminum, nitrate, and ammonia were generated for each soil horizon in three plots from two forest types. The three plots represent a control, treatment with primary sewage, and treatment with secondary sewage. There were no replicates. Differences in soil chemistry and/or structure between the three plots were assumed to be due to sewage application. Residual difference for a parameter, or changes remaining after 44 months, were considered significant if at least one Analysis of Variance (ANOVA) by horizon produced an F value corresponding to a p of .05. Analyses, data, and pH graphs are presented for future reference.

  9. Assessment of Organic Matter Content in Highland Forest Soils in Central Anatolia of Turkey

    NASA Astrophysics Data System (ADS)

    Göl, C.; Erşahin, S.

    2012-04-01

    Forest soils are important pool for organic carbon worldwide. Global warming is expected to influence forest soils due to that it may alter the balance between addition and decomposition of litter. Orographic effect of climate on organic matter in forest soils may be a good indicator of likely impact of climate change on these forest soils. This study was conducted to assess the relations between organic matter content of forest soils and elevation. Data of organic matter content from previous studies conducted on different elevations in semi-arid regions of Central Anatolia region of Turkey were used. A significant positive correlation occurred between elevation and organic matter content. The relation could be modeled with a fist degree linear regression equation. We concluded that topographic attributes may be used to forecast adequately likely impact of climate change on carbon emissions from forest soils in mountainous regions.

  10. Soil Does Not Explain Monodominance in a Central African Tropical Forest

    PubMed Central

    Peh, Kelvin S. -H.; Sonké, Bonaventure; Lloyd, Jon; Quesada, Carlos A.; Lewis, Simon L.

    2011-01-01

    Background Soil characteristics have been hypothesised as one of the possible mechanisms leading to monodominance of Gilbertiodendron dewerei in some areas of Central Africa where higher-diversity forest would be expected. However, the differences in soil characteristics between the G. dewevrei-dominated forest and its adjacent mixed forest are still poorly understood. Here we present the soil characteristics of the G. dewevrei forest and quantify whether soil physical and chemical properties in this monodominant forest are significantly different from the adjacent mixed forest. Methodology/Principal Findings We sampled top soil (0–5, 5–10, 10–20, 20–30 cm) and subsoil (150–200 cm) using an augur in 6 × 1 ha areas of intact central Africa forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450–800 m apart), all chosen to be topographically homogeneous. Analysis – subjected to Bonferroni correction procedure – revealed no significant differences between the monodominant and mixed forests in terms of soil texture, median particle size, bulk density, pH, carbon (C) content, nitrogen (N) content, C:N ratio, C:total NaOH-extractable P ratio and concentrations of labile phosphorous (P), inorganic NaOH-extractable P, total NaOH-extractable P, aluminium, barium, calcium, copper, iron, magnesium, manganese, molybdenum, nickel, potassium, selenium, silicon, sodium and zinc. Prior to Bonferroni correction procedure, there was a significant lower level of silicon concentration found in the monodominant than mixed forest deep soil; and a significant lower level of nickel concentration in the monodominant than mixed forest top soil. Nevertheless, these were likely to be the results of multiple tests of significance. Conclusions/Significance Our results do not provide clear evidence of soil mediation for the location of monodominant forests in relation to adjacent mixed forests. It is also likely that G

  11. SOC storage in Swiss forest soils - driven by climate or historical land-use?

    NASA Astrophysics Data System (ADS)

    Gosheva, Sia; Walthert, Lorenz; Niklaus, Pascal; Zimmermann, Stephan; Hagedorn, Frank

    2015-04-01

    Soils store the most carbon of all terrestrial ecosystems, with forest soils being particularly carbon-rich (Schmidt et al. 2011; Hagedorn et al. 2010; Jobaggy & Jackson 2000). The C balance of soils might be altered by land-use changes such as in Switzerland, where the forest cover has increased by approximately 22% in the last century (Ginzler et al. 2011). The objectives of this study were 1) to determine whether historical forest cover change has an impact on soil organic carbon (SOC) storage in Swiss forests, and 2) to estimate the influence of climate on C-stocks in the organic layer and the mineral soil. In our study, we reconstructed forest cover changes for the last 150 years for the coordinates of 1000 soil profiles from the soil database of the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). We evaluated historical and modern topographic maps using ArcGIS, classifying current forest sites into permanently (≥150y) forested and newly forested sites (<150y). To identify the impact of climate and historic land-use change on SOC storage, we statistically analyzed the influence of the estimated forest ages of the sites and of potentially additional drivers such as topography, climate, and soil properties on SOC stocks. Contrary to our expectations, our results indicate slightly higher SOC stocks in younger forest sites compared to permanently forested ones. This result could be observed in both organic layer (28,65 vs. 22,23 t C ha-1) and mineral soil (131,38 vs. 113,68 t C ha-1). We attribute the slightly smaller SOC stocks in the younger forests to their inherently higher SOC-stocks, as associated with favorable land previously used for grassland. Moreover, we observed higher SOC stocks under coniferous than under deciduous forest - however, this was only evident in the organic layer, but not in the mineral soil. Soil carbon increased significantly with decreasing mean annual temperature (MAT) and increasing precipitation (MAP), in

  12. Does drought alter hydrological functions in forest soils?

    NASA Astrophysics Data System (ADS)

    Gimbel, Katharina F.; Puhlmann, Heike; Weiler, Markus

    2016-04-01

    Climate change is expected to impact the water cycle and severely affect precipitation patterns across central Europe and in other parts of the world, leading to more frequent and severe droughts. Usually when projecting drought impacts on hydrological systems, it is assumed that system properties, like soil properties, remain stable and will not be affected by drought events. To study if this assumption is appropriate, we address the effects of drought on the infiltration behavior of forest soils using dye tracer experiments on six sites in three regions across Germany, which were forced into drought conditions. The sites cover clayey-, loamy- and sandy-textured soils. In each region, we compared a deciduous and a coniferous forest stand to address differences between the main tree species. The results of the dye tracer experiments show clear evidence for changes in infiltration behavior at the sites. The infiltration changed at the clayey plots from regular and homogeneous flow to fast preferential flow. Similar behavior was observed at the loamy plots, where large areas in the upper layers remained dry, displaying signs of strong water repellency. This was confirmed by water drop penetration time (WDPT) tests, which revealed, in all except one plot, moderate to severe water repellency. Water repellency was also accountable for the change of regular infiltration to fingered flow in the sandy soils. The results of this study suggest that the drought history or, more generally, the climatic conditions of a soil in the past are more important than the actual antecedent soil moisture status regarding hydrophobicity and infiltration behavior; furthermore, drought effects on infiltration need to be considered in hydrological models to obtain realistic predictions concerning water quality and quantity in runoff and groundwater recharge.

  13. Evaluation of metric precision for a riparian forest survey.

    PubMed

    Barker, Jerry R; Bollman, Michael; Ringold, Paul L; Sackinger, Jennifer; Cline, Steven P

    2002-04-01

    This article evaluates the performance of a protocol to monitor riparian forests in western Oregon, United States based on the quality of the data obtained from a field survey. Precision is the criteria used to determine the quality of 19 field and 6 derived metrics. The derived metrics were calculated from the field data. The survey consisted of 110 riparian sites on public and private lands that were sampled during the summers of 1996 and 1997. In order to calculate metric precision, some of the field plots were re-measured. Metric precision was defined in terms of the coefficient of variability (CV) and standard deviation and then compared with a pre-defined data quality objective (DQO). A metric was considered precise if the CV met or exceeded the DQO. The geomorphology metrics were not precise while the forest stand inventory metrics and forest cover metrics, with some exceptions, were precise. The precision for many of the field and derived metrics compared favorably with the level of precision for similar metrics reported in the literature. Recommendations are made to improve the precision for some metrics and they include changing the way precision is calculated, re-defining the field protocol, or improving field training. PMID:15900665

  14. Soil fungal communities of montane natural secondary forest types in China.

    PubMed

    Cheng, Fei; Wei, Xin; Hou, Lin; Shang, Zhengchun; Peng, Xiaobang; Zhao, Peng; Fei, Zhaoxue; Zhang, Shuoxin

    2015-06-01

    Distinctive plant communities may provide specific physical and chemical properties with soils by specific litters and root exudates to exert effects on soil microorganisms. Past logging activities in the Qinling Mountains induced diverse natural secondary forest types (NSFTs). How these recovered NSFTs regulate patterns of soil microbial communities remain limited. In the study, we used terminal-restriction fragment length polymorphism (T-RFLP) to precisely determine forest type-specific soil fungal diversity and composition in five NSFTs. Our results indicated that NSFTs had significant impacts on the soil fungal communities. The most diverse fungal species were found in the Armand pine (Pinus armandi) and Chinese pine (Pinus tabulaeformis) forest soils, followed by sharptooth oak (Quercus aliena var. acuteserrata) and Chinese pine-sharptooth oak forest soils, the wilson spruce (Picea wilsonii) forests had the lowest soil fungal diversity. The analyses of community composition suggested that the fungal communities of Armand pine forest soils were similar to those of Chinese pine forest soils, while other communities prominently differed from each other. Stepwise multiple regression analysis revealed that soil silt, clay, pH, and ammonium nitrogen had intimate linkages with soil fungal diversity. Furthermore, the patterns of soil fungal communities were strongly governed by the specific soil environments of the tested NSFTs, as described by canonical correspondence analysis (CCA). Finally, our study showed that soil fungal communities may be mediated by NSFTs via specific soil edaphic status. Hence, such a comparable study may provide fundamental information for fungal diversity and community structure of natural forests and assist with better prediction and understanding how soil fungal composition and function alter with forest type transformation. PMID:26025170

  15. Nitrogen-induced reduction in soil respiration of European forests

    NASA Astrophysics Data System (ADS)

    Berridge, Callum; Fleischer, Katrin; Bistinas, Ioannis; Ekici, Altug; Dolman, Albertus

    2014-05-01

    Soil heterotrophic respiration is parameterized in vegetation models as a temperature-dependent decay function, and is usually spatially constant. We test this fundamental assumption with chamber-based observations of the soil carbon efflux along a >1,100km transect throughout European forests, where the latitude is kept constant to control for insolation. We find a modest, but significant, inter-site linear correlation between air temperature and carbon efflux (r2 = 0.32, p=0.02), but not at 5cm depth soil temperature (r2 = -0.02, p=0.4). Average midday respiration increased West-East and correlates well with distance from the coast (r2 = 0.55, p<0.02). Since soil carbon content proved to be a poor explanatory variable (r2=0.04, p=0.5), we turn our attention to nitrogen deposition to find a strong inverse relationship (r2=-0.5, p<0.01; linear model). We are thus able to reject the null hypothesis that there is no spatial variation in soil efflux amongst comparable sites along the same latitude. Critically, we compliment our analysis with independently measured FLUXNET data that accord with our field observations. In both cases, nitrogen is a more reliable predictor of carbon efflux at the inter-site, grid-size scale than temperature. We explain the reduction in soil respiration as a result of nitrogen inhibition of decomposition.

  16. Controls of Soil Spatial Variability in a Dry Tropical Forest.

    PubMed

    Pulla, Sandeep; Riotte, Jean; Suresh, H S; Dattaraja, H S; Sukumar, Raman

    2016-01-01

    We examined the roles of lithology, topography, vegetation and fire in generating local-scale (<1 km2) soil spatial variability in a seasonally dry tropical forest (SDTF) in southern India. For this, we mapped soil (available nutrients, Al, total C, pH, moisture and texture in the top 10 cm), rock outcrops, topography, all native woody plants ≥1 cm diameter at breast height (DBH), and spatial variation in fire frequency (times burnt during the 17 years preceding soil sampling) in a permanent 50-ha plot. Unlike classic catenas, lower elevation soils had lesser moisture, plant-available Ca, Cu, Mn, Mg, Zn, B, clay and total C. The distribution of plant-available Ca, Cu, Mn and Mg appeared to largely be determined by the whole-rock chemical composition differences between amphibolites and hornblende-biotite gneisses. Amphibolites were associated with summit positions, while gneisses dominated lower elevations, an observation that concurs with other studies in the region which suggest that hillslope-scale topography has been shaped by differential weathering of lithologies. Neither NO3(-)-N nor NH4(+)-N was explained by the basal area of trees belonging to Fabaceae, a family associated with N-fixing species, and no long-term effects of fire on soil parameters were detected. Local-scale lithological variation is an important first-order control over soil variability at the hillslope scale in this SDTF, by both direct influence on nutrient stocks and indirect influence via control of local relief. PMID:27100088

  17. The cost-effectiveness of biodiversity surveys in tropical forests.

    PubMed

    Gardner, Toby A; Barlow, Jos; Araujo, Ivanei S; Avila-Pires, Teresa Cristina; Bonaldo, Alexandre B; Costa, Joana E; Esposito, Maria Cristina; Ferreira, Leandro V; Hawes, Joseph; Hernandez, Malva I M; Hoogmoed, Marinus S; Leite, Rafael N; Lo-Man-Hung, Nancy F; Malcolm, Jay R; Martins, Marlucia B; Mestre, Luiz A M; Miranda-Santos, Ronildon; Overal, William L; Parry, Luke; Peters, Sandra L; Ribeiro-Junior, Marco Antônio; da Silva, Maria N F; da Silva Motta, Catarina; Peres, Carlos A

    2008-02-01

    The identification of high-performance indicator taxa that combine practical feasibility and ecological value requires an understanding of the costs and benefits of surveying different taxa. We present a generic and novel framework for identifying such taxa, and illustrate our approach using a large-scale assessment of 14 different higher taxa across three forest types in the Brazilian Amazon, estimating both the standardized survey cost and the ecological and biodiversity indicator value for each taxon. Survey costs varied by three orders of magnitude, and dung beetles and birds were identified as especially suitable for evaluating and monitoring the ecological consequences of habitat change in our study region. However, an exclusive focus on such taxa occurs at the expense of understanding patterns of diversity in other groups. To improve the cost-effectiveness of biodiversity research we encourage a combination of clearer research goals and the use of an objective evidence-based approach to selecting study taxa. PMID:18031554

  18. Effect of soil bulk density on forest tree seedlings

    NASA Astrophysics Data System (ADS)

    Kormanek, Mariusz; Banach, Jacek; Sowa, Paweł

    2015-01-01

    The paper presents the results of an analysis of the influence of soil bulk density in a forest nursery plot on the growth and quality parameters of Scots pine and European beech seedlings. Particular density variants were obtained using a tractor device exerting controlled pressure on the soil, while field examinations were performed on an area of `Kłaj' forest nursery in Niepołomice Forest District. Three series of plots were prepared for each species, applying a unit pressure of the values of 50, 100, 150, 200, 250 kPa, corresponding to the dry bulk density in the range of 1.03-1.19 g cm-3, and control plots without the pressure. Seeds of the examined species were sown on the prepared plots, and after 6 months of growth the seedlings were subjected to biometric analysis determining differentiation in root neck diameter, length of the above-ground part and root system, as well as dry mass of particular parts of the plant. The quality of the seedlings was also determined using the method of Schmidt-Vogt. The results obtained show that the change in dry bulk density soil significantly affected most of the growth parameters of the examined seedlings. Especially high negative correlations were obtained for the length and dry mass of the root system. A significant influence of dry bulk density variant on all growth parameters of Scots pine seedlings, and on some parameters of European beech was demonstrated. An increase in soil bulk density clearly caused also a deterioration of European beech seedlings quality

  19. Soil Respiration Declines Following Beetle - Induced Forest Mortality in a Lodgepole Pine Forest

    NASA Astrophysics Data System (ADS)

    Borkhuu, B.; Peckham, S. D.; Norton, U.; Ewers, B. E.; Pendall, E.

    2014-12-01

    Lodgepole pine (Pinus contorta var. latifolia) forests in northern Colorado and southeast Wyoming have been undergoing a major mortality event owing to mountain pine beetle (Dendroctonus ponderosae) infestation since 2007. We studied biotic and abiotic drivers of growing season soil respiration in four mature stands experiencing different levels of mortality between 2008 and 2012 in the Medicine Bow Mountains, southeastern Wyoming, USA. For five years, beetle infestation significantly altered forest structure. Stand mortality was 30% and more than 80% in stands with the lowest and highest mortality, respectively. Understory vegetation cover increased by 50% for five years following beetle infestation. Needlefall was increased by more than 50% during first two years of beetle infestation compared to the pre-disturbance period. We did not observe an immediate increase in soil respiration following beetle infestation as suggested by some researchers. Soil respiration rates in midsummer ranged from 1.4 ± 0.1 μmol m-2 s-1 in stands with highest mortality to 3.1 ± 0.2 μmol m-2s-1 in uninfested stand. Live tree basal area was the dominant factor controlling soil respiration, explaining more than 60% of the interannual and spatial variations in response to the disturbance. In addition, soil respiration was significantly correlated with fine root biomass, which explained 55% of variations, providing strong evidence that autotrophic respiration dominated the forest soil respiration flux. Furthermore, the seasonality of soil respiration was controlled mainly by mean monthly precipitation and mid-day photosynthetically active radiation. Each factor predicted from 30% to 50% of seasonal soil respiration variability with the highest correlation coefficients in stand with the lowest mortality. Our results clearly indicate that the reduction of photosynthesis in trees over the infestation period significantly reduced soil respiration. The remaining activity in dead stands may

  20. 77 FR 73974 - Information Collection: Arapaho-Roosevelt National Forest Visitor Surveys for Recreation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ...In accordance with the Paperwork Reduction Act of 1995, the Forest Service is seeking comments from all interested individuals and organizations on the new information collection, Arapaho-Roosevelt National Forest Visitor Surveys for Transportation System Alternatives...

  1. Threshold Responses to Soil Moisture Deficit by Trees and Soil in Tropical Rain Forests: Insights from Field Experiments

    PubMed Central

    Meir, Patrick; Wood, Tana E.; Galbraith, David R.; Brando, Paulo M.; Da Costa, Antonio C. L.; Rowland, Lucy; Ferreira, Leandro V.

    2015-01-01

    Many tropical rain forest regions are at risk of increased future drought. The net effects of drought on forest ecosystem functioning will be substantial if important ecological thresholds are passed. However, understanding and predicting these effects is challenging using observational studies alone. Field-based rainfall exclusion (canopy throughfall exclusion; TFE) experiments can offer mechanistic insight into the response to extended or severe drought and can be used to help improve model-based simulations, which are currently inadequate. Only eight TFE experiments have been reported for tropical rain forests. We examine them, synthesizing key results and focusing on two processes that have shown threshold behavior in response to drought: (1) tree mortality and (2) the efflux of carbon dioxdie from soil, soil respiration. We show that: (a) where tested using large-scale field experiments, tropical rain forest tree mortality is resistant to long-term soil moisture deficit up to a threshold of 50% of the water that is extractable by vegetation from the soil, but high mortality occurs beyond this value, with evidence from one site of increased autotrophic respiration, and (b) soil respiration reaches its peak value in response to soil moisture at significantly higher soil moisture content for clay-rich soils than for clay-poor soils. This first synthesis of tropical TFE experiments offers the hypothesis that low soil moisture–related thresholds for key stress responses in soil and vegetation may prove to be widely applicable across tropical rain forests despite the diversity of these forests. PMID:26955085

  2. Spatial heterogeneity of radiocesium concentration on a forest floor soil in a broadleaf and mixed forest in Fukushima, Japan

    NASA Astrophysics Data System (ADS)

    Takada, Momo; Yamada, Toshihiro; Takahara, Teruhiko; Okuda, Toshinori

    2015-04-01

    Radiocesium in Fukushima forests derived from the nuclear power plant accident still remains in the surface of forest floors. Its distribution is known to show spatial heterogeneity, but little is reported about causes generating it. Horizontal distribution of radiocesium within a forest community needs to be clarified for understanding spatio-temporal dynamics of radiocesium within a forest community and its outflow from the ecosystem to others (e.g. downstream). Here, we hypothesized as follows; environmental spatial heterogeneity of a forest floor within a forest community generated by vegetation creates the spatial variation of distribution of radiocesium. We examined whether the radiocesium accumulates at the bases of trees, and the amount of the radiocesium is related to tree size and morphological characteristics of the tree such as tree species and bark properties. The field surveys were conducted in a broadleaf and mixed forest dominated by Japanese oak (Quercus crispula) and Japanese fir (Abies firma) in Soma city in Fukushima Prefecture in August and November, 2014. A 20 m × 20 m plot was established in the study site. Top soils (0 - 5 cm) were collected from 121 points in a grid system of every 2 m interval within the plot and additional 136 points from south and north sides at bases of all trees (≥ 5 cm of diameters at breast height) in the plot. Diameters at breast height of all the trees were measured, and the tree species were identified. The soil samples were dried and measured by a germanium detector. Activity concentrations of Cs-137 were decay-correlated to the data of the first field survey. Average concentration of Cs-137 radioactivity in the plot was 14,007 Bq/kg and its coefficient of variance was 74 %, showing large spatial variation of radiocesium distribution on the forest floor. Average concentration collected in the grid points 2 m apart each other was 10,826 Bq/kg, while average concentration from the bases of all trees was 16

  3. Soil-Earthworm-Litter System Controls on the Soil Aggregates and Soil Organic Matter Dynamics in Eastern Deciduous Forests

    NASA Astrophysics Data System (ADS)

    Ma, Yini; Filley, Timothy; Johnston, Cliff; Szlavecz, Kathy; McCormick, Melissa

    2010-05-01

    Many soils from forests in northern North America are undergoing a recent invasion of European Lumbricid earthworms with important implications for soil organic carbon (SOC) dynamics. Our work seeks to identify how native and invasive earthworm (EW) activity alters the relative importance of physical, chemical, and biochemical protection mechanisms controlling SOM stabilization in deciduous forests by changing the dynamics of soil particulate organic matter (POM) and aggregates. Within forests of the Smithsonian Environmental Research Center (SERC) in coastal Maryland, USA, wood and litter amendment plots were established in high, low and no EW activity areas within forests of different stand age and land use history to study EW impacts to litter-soil systems. Older, mature successional forests have relatively fewer or no earthworms while forests with agricultural disturbance less than 75 years exhibit the greatest number of individuals. Our previous work demonstrated that the plant biopolymer chemistry of both decayed litter and soil (0-5 cm) POM is driven by differences in EW activity and is responsible for the differences observed in lignin and root aliphatic matter accumulation in this system. In the present study we compare soils to a depth of 15 cm among plots with 5 years of wood and litter amendment to track the control of EW activity on the vertical transport and microaggregation of litter. Elemental C&N, 13C, 15N abundances, and diffuse reflectance Fourier transform infrared spectra (DR-FTIR) data will be presented for bulk soil and size-density separated soil fractions. These plots have variable land use histories over the last 250 yrs which is mostly reflected in their stable 15N and 13C values of mineral bound SOC with depth but earthworm activity seems to have a control on the degree of isotope change with depth. Our results from analysis of stable isotopes and lignin phenols in soil indicate the invasive EW feeding habits and activity are a major

  4. Soil respiration in tropical seasonal forest of Southern Vietnam

    NASA Astrophysics Data System (ADS)

    Avilov, Vitaly; Anichkin, Alexandr; Descherevskaya, Olga; Evdokimova, Elena; Nguyen Van, Thinh; Novichonok, Artyom; Do Phong, Luu; Kurbatova, Julia; Lopes de Gerenyu, Valentin

    2013-04-01

    Soil respiration was monitored as a part of a complex research of carbon balance in Nam Cat Tien National Park in Southern Vietnam (NCT site in AsiaFlux index). The study area is described as a tropical monsoon valley tall-stand forest at altitude about 156 m above sea level, mean annual air temperature is 26.2°C, with fluctuations of monthly averaged temperatures within 4°C; mean annual precipitation is 2470 mm with a distinct alternation of wet and dry seasons (Dong Phu weather station, 1976-1990). Measurements were made every 10-15 days during year 2012 at 6 plots that differ in soil and forest type, mostly in Lagerstroemia- or Dipterocarpus-dominated tree stands. Five chambers Ø162 mm were installed at each plot. CO2 concentration was defined with LI-820 gas analyser and 20 ml syringes (three syringes/samples per chamber) up to August 2012, and by means of closed-loop continuous field analysis from August on. Our studies have shown significant temporal and spatial variability of soil respiration in tropical rainforest. Namely, highest annual CO2 efflux rates were calculated for cambisols under lagerstroemia-dominated tree stand and for light sandy fluvisols under dipterocarpus-dominated tree stand (1694.3±546.0 and 1628.1±442.7 gC•m-2•y-1 respectively). Noteworthy is that the content of organic carbon in these soils varies utterly. Lowest annual CO2 efflux rate was calculated for clay-slate leptosols under dipterocarpus-dominated tree stand (972.7±716.5 gC•m-2•y-1). We also observed a significant impact of termites activity on site-scale spatial variability of soil respiration. Seasonal patterns of soil respiration rates were conformed for all plots except one on sandy soils. The beginning of rainy season in April did not result in higher soil respiration rates, but rates did rise in August - October, at the end of rainy season. Apparently this pattern is related to the accumulation of decomposed organic matter in soil and to the deficient

  5. The influence of vegetation and soil characteristics on active-layer thickness of permafrost soils in boreal forest.

    PubMed

    Fisher, James P; Estop-Aragonés, Cristian; Thierry, Aaron; Charman, Dan J; Wolfe, Stephen A; Hartley, Iain P; Murton, Julian B; Williams, Mathew; Phoenix, Gareth K

    2016-09-01

    Carbon release from thawing permafrost soils could significantly exacerbate global warming as the active-layer deepens, exposing more carbon to decay. Plant community and soil properties provide a major control on this by influencing the maximum depth of thaw each summer (active-layer thickness; ALT), but a quantitative understanding of the relative importance of plant and soil characteristics, and their interactions in determine ALTs, is currently lacking. To address this, we undertook an extensive survey of multiple vegetation and edaphic characteristics and ALTs across multiple plots in four field sites within boreal forest in the discontinuous permafrost zone (NWT, Canada). Our sites included mature black spruce, burned black spruce and paper birch, allowing us to determine vegetation and edaphic drivers that emerge as the most important and broadly applicable across these key vegetation and disturbance gradients, as well as providing insight into site-specific differences. Across sites, the most important vegetation characteristics limiting thaw (shallower ALTs) were tree leaf area index (LAI), moss layer thickness and understory LAI in that order. Thicker soil organic layers also reduced ALTs, though were less influential than moss thickness. Surface moisture (0-6 cm) promoted increased ALTs, whereas deeper soil moisture (11-16 cm) acted to modify the impact of the vegetation, in particular increasing the importance of understory or tree canopy shading in reducing thaw. These direct and indirect effects of moisture indicate that future changes in precipitation and evapotranspiration may have large influences on ALTs. Our work also suggests that forest fires cause greater ALTs by simultaneously decreasing multiple ecosystem characteristics which otherwise protect permafrost. Given that vegetation and edaphic characteristics have such clear and large influences on ALTs, our data provide a key benchmark against which to evaluate process models used to predict

  6. Soil water samplers in ion balance studies on acidic forest soils

    SciTech Connect

    Rasmussen, L.; Joergensen, P.; Kruse, S.

    1986-04-01

    During the last years an increasing consciousness has appeared of the injurious effects of acid rain on the forest ecosystems both in Europe and North America. At several localities ion balance studies have been implemented in order to evaluate the impact of the atmospheric deposition of acidic substances and heavy metals on the forest ecosystem. In many localities the leaching of material to the ground water or output from the ecosystem has to be determined by means of tensiometer measurements and soil water sampling. Many different soil water samplers are available on the market and they show useful applicability under the given circumstances. But in many cases soil water samples taken with different equipment give incommensurable results leading to differing explanations of the effects of acid precipitation on elements and their cycling in the ecosystem. The purpose of the present study is twofold. Firstly, the sorption characteristics of different types of soil water samplers are examined under acidic soil conditions both by installation in the field and by laboratory experiments. Secondly, a new method is introduced for current and constant soil water sampling under varying soil suctions in the unsaturated zone.

  7. Distinct temperature sensitivity of soil carbon decomposition in forest organic layer and mineral soil

    PubMed Central

    Xu, Wenhua; Li, Wei; Jiang, Ping; Wang, Hui; Bai, Edith

    2014-01-01

    The roles of substrate availability and quality in determining temperature sensitivity (Q10) of soil carbon (C) decomposition are still unclear, which limits our ability to predict how soil C storage and cycling would respond to climate change. Here we determined Q10 in surface organic layer and subsurface mineral soil along an elevation gradient in a temperate forest ecosystem. Q10 was calculated by comparing the times required to respire a given amount of soil C at 15 and 25°C in a 350-day incubation. Results indicated that Q10 of the organic layer was 0.22–0.71 (absolute difference) higher than Q10 of the mineral soil. Q10 in both the organic layer (2.5–3.4) and the mineral soil (2.1–2.8) increased with decreasing substrate quality during the incubation. This enhancement of Q10 over incubation time in both layers suggested that Q10 of more labile C was lower than that of more recalcitrant C, consistent with the Arrhenius kinetics. No clear trend of Q10 was found along the elevation gradient. Because the soil organic C pool of the organic layer in temperate forests is large, its higher temperature sensitivity highlights its importance in C cycling under global warming. PMID:25270905

  8. [Effects of exotic Larix kaempferi on forest soil quality and bacterial diversity].

    PubMed

    Yang, Xin; Cao, Jing; Dong, Mao-Xing; Ma, Xiao-Jun

    2008-10-01

    The study on the soil quality and bacterial diversity under 8-30 years old exotic Larix kaempferi, native Pinus tabulaeformis, and secondary deciduous broadleaf forest stands in Xiaolong-shan Mountains of Gansu, Northwest China showed that the soil pH under different forest stands had no distinct variation, but soil moisture content was increased with increasing age of forest stands. Soil organic matter and nitrogen contents were the highest under secondary deciduous forest, followed by under L. kaermpferi, and P. tabulaeformis. However, the soils under different ages of forest stands had no obvious variations in their organic matter and nitrogen contents, suggesting that tree species was the main factor affecting soil quality. Compared with P. tabulaeformis, exotic L. kaempferi could significantly increase soil organic matter and nitrogen contents. PCR-DGGE banding patterns suggested that the soil under secondary deciduous broadleaf forest had the highest bacterial diversity, followed by under L. kaempferi, and P. tabulaeformis. The sequenced DGGE bands were classified into three bacterial groups, i. e., Proteobacteria, Cytophaga - Flavobacterium - Bacteroides, and high G + C content gram-positive type, among which, Proteobacteria occurred most frequently. Further detailed analyses suggested that the soil bacterial compositions under exotic Larix stands were more similar to each other than those under pine and secondary deciduous broadleaf forests. It was concluded that exotic L. kaempferi induced the changes of microbial diversity in the forest soils of this region. PMID:19123342

  9. Denitrification and N2O emission from forested and cultivated alluvial clay soil

    USGS Publications Warehouse

    Ullah, S.; Breitenbeck, G.A.; Faulkner, S.P.

    2005-01-01

    Restored forested wetlands reduce N loads in surface discharge through plant uptake and denitrification. While removal of reactive N reduces impact on receiving waters, it is unclear whether enhanced denitrification also enhances emissions of the greenhouse gas N2O, thus compromising the water-quality benefits of restoration. This study compares denitrification rates and N2O:N2 emission ratios from Sharkey clay soil in a mature bottomland forest to those from an adjacent cultivated site in the Lower Mississippi Alluvial Valley. Potential denitrification of forested soil was 2.4 times of cultivated soil. Using intact soil cores, denitrification rates of forested soil were 5.2, 6.6 and 2.0 times those of cultivated soil at 70, 85 and 100% water-filled pore space (WFPS), respectively. When NO3 was added, N2O emissions from forested soil were 2.2 times those of cultivated soil at 70% WFPS. At 85 and 100% WFPS, N2O emissions were not significantly different despite much greater denitrification rates in the forested soil because N2O:N2 emission ratios declined more rapidly in forested soil as WFPS increased. These findings suggest that restoration of forested wetlands to reduce NO3 in surface discharge will not contribute significantly to the atmospheric burden of N2O. ?? Springer 2005.

  10. Early forest soils and their role in Devonian global change

    SciTech Connect

    Retallack, G.J.

    1997-04-25

    A paleosol in the Middle Devonian Aztec Siltstone of Victoria Land, Antarctica, is the most ancient known soil of well-drained forest ecosystems. Clay enrichment and chemical weathering of subsurface horizons in this and other Devonian forested paleosols culminate a long-term increase initiated during the Silurian. From Silurian into Devonian time, red clayey calcareous paleosols show a greater volume of roots and a concomitant decline in the density of animal burrows. These trends parallel the decline in atmospheric carbon dioxide determined from isotopic records of pedogenic carbonate in these same paleosols. The drawdown of carbon dioxide began well before the Devonian appearance of coals, large logs, and diverse terrestrial plants and animals, and it did not correlate with temporal variation in volcanic or metamorphic activity. The early Paleozoic greenhouse may have been curbed by the evolution of rhizospheres with an increased ratio of primary to secondary production and by more effective silicate weathering during Silurian time. 14 refs., 3 figs.

  11. Do Forest Age and Soil Depth Affect Carbon and Nitrogen Adsorption in Mineral Horizons?

    NASA Astrophysics Data System (ADS)

    Spina, P. G.; Lovett, G. M.; Fuss, C. B.; Goodale, C. L.; Lang, A.; Fahey, T.

    2015-12-01

    Mineral soils retain large amounts of organic matter through sorption on the surfaces of mineral soils, the largest pools of carbon (C) and nitrogen (N) in the forests of the northeastern U.S. In addition to determining organic matter storage, adsorption and desorption processes are important controllers of runoff chemistry. We are studying adsorption dynamics of mineral soils collected from a chronosequence of hardwood forest sites in the White Mountains, NH to determine how soils vary in their DOM adsorption capacities as a function of effective C and N saturation. We hypothesize that forest age determines proximity to saturation because young forests may need to mine soil organic matter (SOM) in mineral soils to obtain nitrogen to meet growth demands, while the soils of older forests have had time to reaccumulate SOM, eventually reaching C and N saturation. Consequently, we expect adsorption capacities to first increase with forest age in young forests, as the trees mine C and N from mineral surfaces. They will then decrease with forest age in older forests as mining slows and C and N begin to re-accumulate. Batch experiments were conducted with mineral soil samples and dilutions of forest floor leachate. However, preliminary results from a mature forest site (about 100 years old), which we predicted to be a low point of C and N saturation from decades of mining, contradict expectations. Dissolved organic carbon (DOC) adsorption in its shallow mineral soil layers (0-3 cm below E or A horizons) are lower than younger sites ranging from 20 to about 40 years old. In addition to forest age, soil depths also affect N retention dynamics in forest soils. We hypothesized that deeper mineral soils might have greater adsorption capacities due to the fact that they are exposed to less DOC and DON leaching from organic layers and therefore less saturated. Results from the same mature forest site confirm this. Soils from 3-10 cm depth have more potential to adsorb DOC and

  12. Soil cover in the southern forest-steppe of the Central Russian Upland against the background of centennial climate fluctuations

    NASA Astrophysics Data System (ADS)

    Smirnova, L. G.; Kukharuk, N. S.; Chendev, Yu. G.

    2016-07-01

    Special approaches and algorithms for studying the response of zonal soils and the soil cover of the forest-steppe zone to climate fluctuations were developed on the basis of data of repeated soil surveys. They made it possible to analyze the particular transformations of the soil cover as indicators of short-term climate fluctuations in the southern forest-steppe of the Central Russian Upland. Vector soil maps and related databases on soil polygons were developed using GIS technologies. Changes in the climatic conditions between two rounds of large-scale soil surveys in 1971 and 1991 reflecting the so-called Brückner cycles were identified. A characteristic feature of climate change during that period was the rise in the mean annual air temperature by 0.2°C and an increase in the mean annual precipitation by 83 mm. In response to this change, the area of leached chernozems (Luvic Chernozems) on the interfluves somewhat increased, whereas the area of typical chernozems (Haplic Chernozems) decreased.

  13. Sensitivity of boreal forest carbon balance to soil thaw

    USGS Publications Warehouse

    Goulden, M.L.; Wofsy, S.C.; Harden, J.W.; Trumbore, S.E.; Crill, P.M.; Gower, S.T.; Fries, T.; Daube, B.C.; Fan, S.-M.; Sutton, D.J.; Bazzaz, A.; Munger, J.W.

    1998-01-01

    We used eddy covariance; gas-exchange chambers; radiocarbon analysis; wood, moss, and soil inventories; and laboratory incubations to measure the carbon balance of a 120-year-old black spruce forest in Manitoba, Canada. The site lost 0.3 ?? 0.5 metric ton of carbon per hectare per year (ton C ha-1 year-1) from 1994 to 1997, with a gain of 0.6 ?? 0.2 ton C ha-1 year-1 in moss and wood offset by a loss of 0.8 ?? 0.5 ton C ha-1 year-1 from the soil. The soil remained frozen most of the year, and the decomposition of organic matter in the soil increased 10-fold upon thawing. The stability of the soil carbon pool (~150 tons C ha-1) appears sensitive to the depth and duration of thaw, and climatic changes that promote thaw are likely to cause a net efflux of carbon dioxide from the site.

  14. Uncoupling the complexity of forest soil variation: influence of terrain attributes, spectral indices, and spatial variability

    EPA Science Inventory

    Growing concern over climate and management induced changes to soil nutrient status has prompted interest in understanding the spatial distribution of forest soil properties. Recent advancements in remotely sensed geospatial technologies are providing an increasing array of data...

  15. Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests.

    PubMed

    Zhu, Feifei; Lu, Xiankai; Liu, Lei; Mo, Jiangming

    2015-01-01

    Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al(3+) replacement of Ca(2+) in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests. PMID:25605567

  16. Soil Quality of Restinga Forest: Organic Matter and Aluminum Saturation

    NASA Astrophysics Data System (ADS)

    Rodrigues Almeida Filho, Jasse; Casagrande, José Carlos; Martins Bonilha, Rodolfo; Soares, Marcio Roberto; Silva, Luiz Gabriel; Colato, Alexandre

    2013-04-01

    The restinga vegetation (sand coastal plain vegetation) consists of a mosaic of plant communities, which are defined by the characteristics of the substrates, resulting from the type and age of the depositional processes. This mosaic complex of vegetation types comprises restinga forest in advanced (high restinga) and medium regeneration stages (low restinga), each with particular differentiating vegetation characteristics. Of all ecosystems of the Atlantic Forest, restinga is the most fragile and susceptible to anthropic disturbances. The purpose of this study was evaluating the organic matter and aluminum saturation effects on soil quality index (SQI). Two locations were studied: State Park of the Serra do Mar, Picinguaba, in the city of Ubatuba (23°20' e 23°22' S / 44°48' e 44°52' W), and State Park of Cardoso Island in the city of Cananéia (25°03'05" e 25°18'18" S / 47°53'48" e 48° 05'42" W). The soil samples were collect at a depth of 0-10 cm, where concentrate 70% of vegetation root system. Was studied an additive model to evaluate soil quality index. The shallow root system development occurs due to low calcium levels, whose disability limits their development, but also can reflect on delay, restriction or even in the failure of the development vegetation. The organic matter is kept in the soil restinga ecosystem by high acidity, which reduces the decomposition of soil organic matter, which is very poor in nutrients. The base saturation, less than 10, was low due to low amounts of Na, K, Ca and Mg, indicating low nutritional reserve into the soil, due to very high rainfall and sandy texture, resulting in high saturation values for aluminum. Considering the critical threshold to 3% organic matter and for aluminum saturation to 40%, the IQS ranged from 0.95 to 0.1 as increased aluminum saturation and decreased the soil organic matter, indicating the main limitation to the growth of plants in this type of soil, when deforested.

  17. Invariant community structure of soil bacteria in subtropical coniferous and broadleaved forests

    PubMed Central

    Wang, Xiaoli; Wang, Xiaoling; Zhang, Weixin; Shao, Yuanhu; Zou, Xiaoming; Liu, Tao; Zhou, Lixia; Wan, Songze; Rao, Xingquan; Li, Zhian; Fu, Shenglei

    2016-01-01

    Soil bacteria may be influenced by vegetation and play important roles in global carbon efflux and nutrient cycling under global changes. Coniferous and broadleaved forests are two phyletically distinct vegetation types. Soil microbial communities in these forests have been extensively investigated but few studies have presented comparable data regarding the characteristics of bacterial communities in subtropical forests. We investigated soil bacterial biomass and community composition in three pairs of coniferous and broadleaved forests across a subtropical climatic gradient. We found that bacterial biomass differed between the coniferous and broadleaved forests across the subtropical climate gradient; however, this difference disappeared at some individual sites. In contrast, the same 90 bacterial genera were found in both forest types, and their relative abundances didn’t differ between the forest types, with the exception of one genus that was more abundant in broadleaved forests. Soil nitrogen or moisture was associated with bacterial groups in the coniferous and broadleaved forests, respectively. Thus, we inferred that these forests can respond differently to future changes in nitrogen deposition or precipitation. This study highlights soil bacterial invariant community composition in contrasting subtropical forests and provides a new perspective on the potential response and feedback of forests to global changes. PMID:26754326

  18. Invariant community structure of soil bacteria in subtropical coniferous and broadleaved forests.

    PubMed

    Wang, Xiaoli; Wang, Xiaoling; Zhang, Weixin; Shao, Yuanhu; Zou, Xiaoming; Liu, Tao; Zhou, Lixia; Wan, Songze; Rao, Xingquan; Li, Zhian; Fu, Shenglei

    2016-01-01

    Soil bacteria may be influenced by vegetation and play important roles in global carbon efflux and nutrient cycling under global changes. Coniferous and broadleaved forests are two phyletically distinct vegetation types. Soil microbial communities in these forests have been extensively investigated but few studies have presented comparable data regarding the characteristics of bacterial communities in subtropical forests. We investigated soil bacterial biomass and community composition in three pairs of coniferous and broadleaved forests across a subtropical climatic gradient. We found that bacterial biomass differed between the coniferous and broadleaved forests across the subtropical climate gradient; however, this difference disappeared at some individual sites. In contrast, the same 90 bacterial genera were found in both forest types, and their relative abundances didn't differ between the forest types, with the exception of one genus that was more abundant in broadleaved forests. Soil nitrogen or moisture was associated with bacterial groups in the coniferous and broadleaved forests, respectively. Thus, we inferred that these forests can respond differently to future changes in nitrogen deposition or precipitation. This study highlights soil bacterial invariant community composition in contrasting subtropical forests and provides a new perspective on the potential response and feedback of forests to global changes. PMID:26754326

  19. Soil-Web: An online soil survey for California, Arizona, and Nevada

    NASA Astrophysics Data System (ADS)

    Beaudette, D. E.; O'Geen, A. T.

    2009-10-01

    Digital soil survey products represent one of the largest and most comprehensive inventories of soils information currently available. The complex structure of these databases, intensive use of codes and scientific jargon make it difficult for non-specialists to utilize digital soil survey resources. A project was initiated to construct a web-based interface to digital soil survey products (STATSGO and SSURGO) for California, Arizona, and Nevada that would be accessible to the general public. A collection of mature, open source applications (including Mapserver, PostGIS and Apache Web Server) were used as a framework to support data storage, querying, map composition, data presentation, and contextual links to related materials. Application logic was written in the PHP language to "glue" together the many components of an online soil survey. A comprehensive website ( http://casoilresource.lawr.ucdavis.edu/map) was created to facilitate access to digital soil survey databases through several interfaces including: interactive map, Google Earth and HTTP-based application programming interface (API). Each soil polygon is linked to a map unit summary page, which includes links to soil component summary pages. The most commonly used soil properties, land interpretations and ratings are presented. Graphical and tabular summaries of soil profile information are dynamically created, and aid with rapid assessment of key soil properties. Quick links to official series descriptions (OSD) and other such information are presented. All terminology is linked back to the USDA-NRCS Soil Survey Handbook which contains extended definitions. The Google Earth interface to Soil-Web can be used to explore soils information in three dimensions. A flexible web API was implemented to allow advanced users of soils information to access our website via simple web page requests. Soil-Web has been successfully used in soil science curriculum, outreach activities, and current research projects

  20. Geology, Soils and Basin-wide variations in Amazon Forest Structure and function

    NASA Astrophysics Data System (ADS)

    Quesada, Carlos Alberto; Phillips, Oliver; Lopes-Gonzales, Gabriela; Lloyd, Jon; Rainfor Team

    2015-04-01

    Forest productivity, tree turnover time and above ground biomass vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil nutrient availability and geology. Forest productivity rates are higher on the most nutrient rich soils close to the Andes while is lower in the ancient, highly weathered soils of central Amazonia. On the other hand above ground biomass is lower in the most productive forests and higher on the least, this being a consequence of higher tree turnover rates in the forests over less weathered and nutrient rich soils. Major geological events have influenced Amazonian soil characteristics profoundly and play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Here we show how geology and soil development combine to shape the functioning of Amazonian forests and its carbon stocks and fluxes. To assess the importance of edaphic properties in affect forest structure and dynamics, soil samples were collected in a total of 154 different forest plots across nine different Amazonian countries. Samples were analyzed for exchangeable cations, C, N, pH with various P fractions and soil physical properties also determined. Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions.

  1. Pyrogenic Carbon in forest soils across climate and soil property gradients in Switzerland

    NASA Astrophysics Data System (ADS)

    Reisser, Moritz; González Domínguez, Beatriz R.; Hagedorn, Frank; Abiven, Samuel

    2016-04-01

    Soil organic carbon (SOC) is an important measure for soil quality. Usually a high organic matter content in soils is favourable for most ecosystems. As a very stable component, pyrogenic organic carbon (PyC) can be of major interest to investigate to potential of organic matter, to persist very long in soils. Recent studies have shown, that the mean residence time of organic matter is not only due to its intrinsic chemical nature, but also to a variety of abiotic and biotic variables set by the ecosystem. Especially for PyC it is unclear, whether its content is related to fire regime, soil properties or other climatic conditions. In this study we wanted to investigate, how climatic and soil-related conditions are influencing the persistence of PyC in soils. Therefore we used a sample set from Swiss forest soil (n = 54), which was designed for the purpose of having most differing climatic conditions (aridity and temperature) and a large range of soil properties (pH between 3.4 and 7.6; clay content between 4.7 % and 60 %). The soils were sampled in the first 20 cm of the mineral horizon on a representative plot area of 40 x 40 m. The soils were sieved to 2 mm and dried prior to the analysis. We used the benzene polycarboxylic acids (BPCA) molecular marker method to quantify and characterize PyC in these soil samples. Despite the large span in environmental conditions, we observed rather small differences in the contribution of PyC to SOC between warmer and colder, as well as between wetter and dryer soils. The PyC content in SOC lies well in range with a global average for forest soils estimated in other studies. Stocks of PyC vary more than the content, because of the large range of SOC contents in the samples. The influence of other parameters like soil properties is still under investigation. Qualitative investigation of the BPCAs showed that the degree of condensation, defined by the relative amount of B6CA in the total BPCA, was higher in warmer soils. This

  2. Responses of soil buffering capacity to acid treatment in three typical subtropical forests.

    PubMed

    Jiang, Jun; Wang, Ying-Ping; Yu, Mengxiao; Li, Kun; Shao, Yijing; Yan, Junhua

    2016-09-01

    Elevated anthropogenic acid deposition can significantly affect forest ecosystem functioning by changing soil pH, nutrient balance, and chemical leaching and so on. These effects generally differ among different forests, and the dominant mechanisms for those observed responses often vary, depending on climate, soil conditions and vegetation types. Using soil monoliths (0-40cm) from pine forest (pioneer), coniferous and broadleaved mixed forest (transitional) and broadleaved forest (mature) in southern China, we conducted a leaching experiment with acid treatments at different pH levels (control: pH≈4.5; pH=3.5; pH=2.5). We found that pH3.5 treatment significantly reduced dissolved organic carbon (DOC) concentrations in leachate from the pioneer forest soil. pH2.5 treatment significantly increased concentrations of NO3(-), SO4(2-), Ca(2+), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the pioneer forest soil, and also concentrations of NO3(-), SO4(2-), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the transitional forest soil. All acid treatments had no significant effects on concentrations of these chemicals in leachate from the mature forest soil. The responses can be explained by the changes in soil pH, acid neutralizing capacity (ANC) and concentrations of Al and Fe. Our results showed that acid buffering capacity of the pioneer or transitional forest soil was lower than that of the mature forest soil. Therefore preserving mature forests in southern China is important for reducing the adverse impacts of high acid deposition on stream water quality at present and into the future. PMID:27185346

  3. Water-depth dependent infiltration into burnt forest soils

    NASA Astrophysics Data System (ADS)

    Langhans, Christoph; Sheridan, Gary; Noske, Phil; Metzen, Daniel; Lane, Patrick

    2014-05-01

    Infiltration into severely burnt forest soils in South Eastern Australia exhibits a behaviour that is at odds with traditional infiltration theories that assumes a coherent soil matrix, which has important implications for upscaling from plot to hillslope. Infiltration patterns were studied at three severely burnt sites with different soils by applying a blue dye solution during rainfall and runon experiments, and subsequent profile excavation. Rainfall and runon rates were varied on each plot, runoff measured, and orthogonal photos taken during quasi-steady states. From transects on these photos average inundation fractions of the surface were measured, and 1.5 mm horizontal resolution DEMs were generated with image-based software. This information was combined in a DEM inundation algorithm that calculated water depth maps for each plot and rainfall and runon rate. At all three sites, nearly 100% of infiltration occurred through macropores that bypass the matrix of a water repellent layer. Average fractions of subsoil dye staining were 3% in shallow soils with a northerly aspect and low trees, 60% in deep soils with southerly aspects and high trees, and 20% in an intermediate soil. This was consistent with runoff coefficients of 0.94 for the shallow soil, 0.08 for the deep soil, and 0.71 for the intermediate soil. Irrespective of the runoff coefficient or dyed fraction there was a positive relationship between average water depth and infiltration rates on a given plot. Functions of water depth vs. bypass infiltration were derived inversely for each plot by matching average infiltration rates with the rates derived from sampling the water depth distributions. Additionally, characteristic bypass infiltration rates for all sites as function of runon and rainfall intensity were derived, normalized by the maximum infiltration rate at full inundation. These infiltration functions represent the water depth-dependent dynamics of runoff generation in bypass infiltration

  4. Soil Respiration Measurements in a Temperate and a Tropical Forest

    NASA Astrophysics Data System (ADS)

    Pitz, S. L.; Szlavecz, K. A.; Xia, L.; Chen, Y.; Gupchup, J. A.

    2009-12-01

    The development of low power sensor technology has allowed for long term, continuous measurements of environmental conditions in remote locations. We have deployed a wireless sensor network to monitor soil temperature, moisture, and carbon dioxide (CO2) concentrations at the Smithsonian Environmental Research Center (SERC). A sister pilot system was deployed at an upland tropical rainforest in Yasuni National Park, Ecuador. Here we compare soil CO2 efflux data from the two systems at similar temperature conditions. At both sites, the chamber and gas well methods were used to quantify soil CO2 efflux. Average soil CO2 efflux measured by the chamber method was 2.3 umol m-2 s-1 ± 0.8 and 2.8 umol m-2 s-1± 0.4 at SERC and Yasuni respectively. The Millington Quirk and the Penman models were used to calculate the efflux. Average effluxes generated by the Millington Quick gas well method were 3.6 umol m-2 s-1 ± 0.2 and 5.6 umol m-2 s-1± 0.4 at SERC and Yasuni, respectively. Soil temperatures varied from 20-23 °C during the time periods that were compared. Concentrations were higher and the variation was larger at shallow depths in the rainforest soil (between 2300 ppm and 5000 ppm versus 2000 ppm to 3000 ppm) than the temperature forest soil at weather conditions. Later, under different temperature and moisture regimes the CO2 concentrations at the shallow depth at SERC have reached values over 20,000 ppm. Rain events were captured in both ecosystems with a sharper pulse at SERC. At both sites soil CO2 efflux correlated with soil moisture strongly than with temperature over short time periods. Soil CO2 effluxes were calculated to be three times higher when using the Penman model versus the Millington Quirk model. Also, the latter model was more comparable to the chamber measurements but the values were still 30-40% greater. Gas well models need to be refined to more accurately reflect the actual efflux and need to incorporate potential for aqueous CO2 transport in

  5. The temporal changes in saturated hydraulic conductivity of forest soils

    NASA Astrophysics Data System (ADS)

    Kornél Szegedi, Balázs

    2015-04-01

    I investigated the temporal variability of forest soils infiltration capacity through compaction. I performed the measurements of mine in The Botanical Garden of Sopron between 15.09.2014 - 15.10.2014. I performed the measurements in 50-50 cm areas those have been cleaned of vegetation, where I measured the bulk density and volume of soil hydraulic conductivity with Tension Disk Infiltrometer (TDI) in 3-3 repetitions. I took undisturbed 160 cm3 from the upper 5 cm layer of the cleaned soil surface for the bulk density measurements. Then I loosened the top 10-15 cm layer of the soil surface with spade. After the cultivation of the soil I measured the bulk density and volume of water conductivity also 3-3 repetitions. Later I performed the hydraulic conductivity (Ksat) using the TDI and bulk density measurements on undisturbed samples on a weekly basis in the study area. I illustrated the measured hydraulic conductivity and bulk density values as a function of cumulative rainfall by using simple graphical and statistical methods. The rate of the soil compaction pace was fast and smooth based on the change of the measured bulk density values. There was a steady downward trend in hydraulic conductivity parallel the compaction. The cultivation increased the hydraulic conductivity nearly fourfold compared to original, than decreased to half by 1 week. In the following the redeposition rate declined, but based on the literature data, almost 3-4 months enough to return the original state before cultivation of the soil hydraulic conductivity and bulk density values. This publication has been supported by AGRARKLIMA.2 VKSZ_12-1-2013-0034 project.

  6. Soil Terpene Emissions in a Subalpine Coniferous Forest: Tree Species, Soil Temperature and Moisture Effects

    NASA Astrophysics Data System (ADS)

    Asensio, D.; Duhl, T.; Greenberg, J.; Guenther, A. B.; Monson, R. K.

    2010-12-01

    Some studies have shown soils can contribute significantly to the canopy level fluxes of volatile organic compounds (VOCs) in some ecosystem types during some seasons. Yet patterns of soil VOCs fluxes as well as controls are poorly known and so the potential importance of soil VOCs emissions on the total global BVOCs emissions from terrestrial sources remains unclear. We measured soil terpene emission at a high-elevation, mixed conifer, subalpine forest site at the Niwot Ridge Ameriflux Site in Colorado. Given the important role of terpenes on the formation of secondary organic aerosols and given that high amounts of terpenes are produced and stored in coniferous tissues (e. g. roots and litter) we focused only on these compounds in this study. The objectives were to quantify soil terpene flux and its contribution to the canopy level flux and to identify environmental variables controlling soil terpene emissions in this forest, such as tree species, tree species density, total soil organic matter content, soil temperature and soil moisture . During the summer 2009 (August), soil terpene emission rates were measured in soil chambers regularly distributed in a 200 x 200 m area around the flux tower. To test the effect of the tree species on soil emissions, additional chambers were placed on relative pure stands of each one of the representative species. The average total monoterterpene emission rate during August 2009 was 21 μg C m-2 h-1. These emissions represent 9% of the total terpene canopy fluxes reported in this forest during the same period on previous summers (August 2007, 238 μg C m-2 h-1). The range of monoterpene emission was found to be high; emissions went up to 368 μg C m-2 h-1 under specific conditions. Total sesquiterpene emissions were much lower than monoterpenes (0.04 ± 0.01 μg C m-2 h-1). Due to the high variability found, no clear effect of the space distribution was identified. However, soil terpene emissions were significantly affected by

  7. Modification to degradation of hexazinone in forest soils amended with sewage sludge.

    PubMed

    Wang, Huili; Wang, Chengjun; Chen, Fan; Ma, Meiping; Lin, Zhenkun; Wang, Wenwei; Xu, Zhengti; Wang, Xuedong

    2012-01-15

    Influences of one sewage sludge on degradation of hexazinone and formation of its major metabolites were investigated in four forest soils (A, B, C and D), collected in Zhejiang Province, China. In non-amended forest soils, the degradation half-life of hexazinone was 21.4, 30.4, 19.4 and 32.8 days in forest soil A, B, C and D, respectively. Degradation could start in soil A and C without lag period because the two soils had been contaminated by this herbicide for a long time, possibly leading to completion of acclimation period of hexazinone-degrading bacteria. In forest soils amended with sewage sludge, the degradation rate constant increased by 17.3% in soil A, 48.2% in soil B, 8.1% in soil C and 51.6% in soil D, respectively. The higher degradation rates (soil A and C) in non-amended soils accord with the lower rate increase in sewage sludge-amended soils. Under non-sterile conditions, biological mechanism accounted for 51.8-62.4% of hexazinone degradation in four soils. Under sterile conditions, the four soils had the similar chemical degradation capacity for hexazinone. In non-amended soil B, only one metabolite (B) was detected, while two metabolites (B and C) were found in sewage sludge-amended soil B. Similarly situated in agricultural soils, N-demethylation at 6-position of triazine ring, hydroxylation at the 4-positon of cyclohexyl group, and removal of the dimethylamino group with formation of a carbonyl group at 6-position of triazine ring appear to be the principal mechanism involved in hexazinone degradation in sewage sludge-amended forest soils. These data will improve understanding of the actual pollution risk as a result of forest soil fertilization with sewage sludge. PMID:22112800

  8. [Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

    PubMed

    Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

    2007-02-01

    The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers. PMID:17450727

  9. [Characteristics of soil ammonia-oxidation microbial communities in different subtropical forests, China].

    PubMed

    Li, Yong-Chun; Liu, Bu-Rong; Guo, Shuai; Wu, Qi-Feng; Qin, Hua; Wu, Jia-Sen; Xu, Qiu-Fang

    2014-01-01

    To investigate the effects of different forest stands in subtropical China on the communities of soil ammonia-oxidizing microorganisms, we characterized the abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and the community structure of AOA in soils under stands of broad-leaved (BF) , Chinese fir (CF) , Pinus massoniana (PF) and moso bamboo (MB) forests using real-time quantitative PCR and denaturing gradient gel electrophoresis (DGGE). The results showed that the AOA gene copy numbers (1.62 x 10(6)-1.88 x 10(7) per gram of dry soil) were significantly higher than those of AOB genes (2.41 x 10(5)-4.36 x 10(5) per gram of dry soil). Significantly higher soil AOA abundance was detected in the MB than that in the CF (P < 0.05), and the latter was significantly higher than that in the BF and PF soils (P < 0.05). There were no significant differences in the soil AOB abundance among the four forest stands. As indicated by DGGE pattern, soil AOA species varied among the four forest stands. There was a difference in the soil AOA communities between the CF and MB stands. The AOA demonstrated a competitive advantage over the AOB in the soils under these major subtropical forests. Soil pH, concentrations of soil available potassium and organic carbon as well as the forest type were the main factors that influence the variation of AOA community structure and diversity. PMID:24765851

  10. Quantifying soil and critical zone variability in a forested catchment through digital soil mapping

    NASA Astrophysics Data System (ADS)

    Holleran, M.; Levi, M.; Rasmussen, C.

    2015-01-01

    Quantifying catchment-scale soil property variation yields insights into critical zone evolution and function. The objective of this study was to quantify and predict the spatial distribution of soil properties within a high-elevation forested catchment in southern Arizona, USA, using a combined set of digital soil mapping (DSM) and sampling design techniques to quantify catchment-scale soil spatial variability that would inform interpretation of soil-forming processes. The study focused on a 6 ha catchment on granitic parent materials under mixed-conifer forest, with a mean elevation of 2400 m a.s.l, mean annual temperature of 10 °C, and mean annual precipitation of ~ 85 cm yr-1. The sample design was developed using a unique combination of iterative principal component analysis (iPCA) of environmental covariates derived from remotely sensed imagery and topography, and a conditioned Latin hypercube sampling (cLHS) scheme. Samples were collected by genetic horizon from 24 soil profiles excavated to the depth of refusal and characterized for soil mineral assemblage, geochemical composition, and general soil physical and chemical properties. Soil properties were extrapolated across the entire catchment using a combination of least-squares linear regression between soil properties and selected environmental covariates, and spatial interpolation or regression residual using inverse distance weighting (IDW). Model results indicated that convergent portions of the landscape contained deeper soils, higher clay and carbon content, and greater Na mass loss relative to adjacent slopes and divergent ridgelines. The results of this study indicated that (i) the coupled application of iPCA and cLHS produced a sampling scheme that captured the greater part of catchment-scale soil variability; (ii) application of relatively simple regression models and IDW interpolation of residuals described well the variance in measured soil properties and predicted spatial correlation of soil

  11. Changes in soil carbon stocks in Brazil due to land use: paired site comparisons and a regional pasture soil survey

    NASA Astrophysics Data System (ADS)

    Assad, E. D.; Pinto, H. S.; Martins, S. C.; Groppo, J. D.; Salgado, P. R.; Evangelista, B.; Vasconcellos, E.; Sano, E. E.; Pavão, E.; Luna, R.; Camargo, P. B.; Martinelli, L. A.

    2013-10-01

    In this paper we calculated soil carbon stocks in Brazil studying 17 paired sites where soil stocks were determined in native vegetation, pastures and crop-livestock systems (CPS), and in other regional samplings encompassing more than 100 pasture soils, from 6.58 to 31.53° S, involving three major Brazilian biomes: Cerrado, Atlantic Forest, and the Pampa. The average native vegetation soil carbon stocks at 10, 30 and 60 cm soil depth were equal to approximately 29, 64, and 92 Mg ha-1, respectively. In the paired sites, carbon losses of 7.5 Mg ha-1 and 11.6 Mg ha-1 in CPS systems were observed at 10 cm and 30 cm soil depths, respectively. In pasture soils, carbon losses were similar and equal to 7.5 Mg ha-1 and 11.0 Mg ha-1 at 10 cm and 30 cm soil depths, respectively. Differences at 60 cm soil depth were not significantly different between land uses. The average soil δ13C under native vegetation at 10 and 30 cm depth were equal to -25.4‰ and -24.0‰, increasing to -19.6‰ and -17.7‰ in CPS, and to -18.9‰, and -18.3‰ in pasture soils, respectively; indicating an increasing contribution of C4 carbon in these agrosystems. In the regional survey of pasture soils, the soil carbon stock at 30 cm was equal to approximately 51 Mg ha-1, with an average δ13C value of -19.67‰. Key controllers of soil carbon stock in pasture sites were sand content and mean annual temperature. Collectively, both could explain approximately half of the variance of soil carbon stocks. When pasture soil carbon stocks were compared with the average soil carbon stocks of native vegetation estimated for Brazilian biomes and soil types by Bernoux et al. (2002) there was a carbon gain of 6.7 Mg ha-1, which is equivalent to a carbon gain of 15% compared to the carbon soil stock of the native vegetation. The findings of this study are consistent with differences found between regional comparisons like our pasture sites and plot-level paired study sites in estimating soil carbon stocks

  12. [Dynamic changes of soil ecological factors in Ziwuling secondary forest area under human disturbance].

    PubMed

    Zhou, Zhengchao; Shangguan, Zhouping

    2005-09-01

    As a widespread natural phenomenon, disturbance is considered as a discrete event occurred in natural ecosystems at various spatial and temporal scales. The occurrence of disturbance directly affects the structure, function and dynamics of ecosystems. Forest logging and forestland assart, the common human disturbances in forest area, have caused the dynamic changes of forest soil ecological factors in a relatively consistent environment. A study on the dynamics of soil bulk density, soil organic matter, soil microbes and other soil ecological factors under different human disturbance (logging and assart, logging but without assart, control) were conducted in the Ziwuling secondary forest area. The results indicated that human disturbance had a deep impact on the soil ecological factors, with soil physical and chemical properties become bad, soil organic matter decreased from 2.2% to 0.8%, and soil stable aggregates dropped more than 30%. The quantity of soil microbes decreased sharply with enhanced human disturbance. Soil organic matter and soil microbes decreased more than 50% and 90%, respectively, and soil bulk density increased from 0.9 to 1.21 g x cm(-3) with increasing soil depth. Ditch edge level also affected the dynamics of soil factors under the same disturbance, with a better soil ecological condition at low-than at high ditch edge level. PMID:16355766

  13. Long lasting effects of the conversion from natural forest to poplar plantation on soil microbial communities.

    PubMed

    Vitali, Francesco; Mastromei, Giorgio; Senatore, Giuliana; Caroppo, Cesarea; Casalone, Enrico

    2016-01-01

    In this study, we evaluate the long-lasting effects on soil microbial communities of a change within a single land-use category, specifically the conversion from natural forest to forest plantation. To minimize the effects of impacts other than land-use (i.e., climatic and anthropogenic), we chose three sites within a Natural Park, with homogeneous orographic and soil texture characteristics. We compared microbial diversity in a total of 156 soil samples from two natural mixed forests and a similar forest converted to poplar plantation about thirty years ago. The diversity and structure of bacterial and fungal communities were investigated by terminal restriction fragments length polymorphism (T-RFLP) analysis of the 16S-rRNA gene and the ITS-rDNA regions, respectively. Bacterial and fungal communities from the forest plantation, compared to those from natural forest soils, showed different community structure and lower α-diversity values, consistently with the significantly higher pH values and lower organic matter content of those soils. β-diversity values, the number of measured and estimated dominant OTUs, and their distribution among the three sites showed that microbial communities from the two natural forests were much more similar to each other than they were to communities from the poplar plantation, suggesting an effect of the forest conversion on the composition and diversity of soil microbial communities. α-diversity in cultivated forest soils had narrower temporal fluctuations than in natural forest soils, suggesting higher temporal stability of microbial communities. Overall, we demonstrated that the conversion from natural forest to forest plantation altered soil microbial communities, changing their structure, lowering their diversity, and causing a spatial and temporal homogenization. PMID:26686617

  14. Response of soil respiration to acid rain in forests of different maturity in southern China.

    PubMed

    Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types. PMID:23626790

  15. Response of Soil Respiration to Acid Rain in Forests of Different Maturity in Southern China

    PubMed Central

    Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types. PMID:23626790

  16. [Soil microbial functional diversity of different altitude Pinus koraiensis forests].

    PubMed

    Han, Dong-xue; Wang, Ning; Wang, Nan-nan; Sun, Xue; Feng, Fu-juan

    2015-12-01

    In order to comprehensively understand the soil microbial carbon utilization characteristics of Pinus koraiensis forests, we took the topsoil (0-5 cm and 5-10 cm) along the 700-1100 m altitude in Changbai Mountains and analyzed the vertical distributed characteristics and variation of microbial functional diversity along the elevation gradient by Biolog microplate method. The results showed that there were significant differences in functional diversity of microbial communities at different elevations. AWCD increased with the extension of incubation time and AWCD at the same soil depth gradually decreased along with increasing altitude; Shannon, Simpson and McIntosh diversity index also showed the same trend with AWCD and three different diversity indices were significantly different along the elevation gradient; Species diversity and functional diversity showed the same variation. The utilization intensities of six categories carbon sources had differences while amino acids were constantly the most dominant carbon source. Principal component analysis (PCA) identified that soil microbial carbon utilization at different altitudes had obvious spatial differentiation, as reflected in the use of carbohydrates, amino acids and carboxylic acids. In addition, the cluster of the microbial diversity indexes and AWCD values of different altitudes showed that the composition of vegetation had a significant impact on soil microbial composition and functional activity. PMID:27112001

  17. Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil

    PubMed Central

    Tng, David Y. P.; Janos, David P.; Jordan, Gregory J.; Weber, Ellen; Bowman, David M. J. S.

    2014-01-01

    Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an “ashbed effect”). PMID:25339968

  18. Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil.

    PubMed

    Tng, David Y P; Janos, David P; Jordan, Gregory J; Weber, Ellen; Bowman, David M J S

    2014-01-01

    Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an "ashbed effect"). PMID:25339968

  19. Effects of biochar on organic nitrogen mineralization of Northeast forest soil

    NASA Astrophysics Data System (ADS)

    Du, Siyao; Tao, Jun; Luo, Xianxiang

    2016-04-01

    These years,Biochar,as a new environmental functional material,received widespread attention of scholars both in China and abroad.Biochar is applied as a soil conditioner which is because it will improve the soil texture and increase plant yields. But the influence of nitrogen cycle while biochar is added to the forest soil is still controversial. This article takes forest soil as the object of research, aiming at learning the effects of different biochar on nitrogen mineralization of forest soil,and that in the case of different incubation temperature.The results show that it can reduce the net mineralization of soil organic nitrogen. That means the addition of biochar could suppress the mineralization of forest soil organic nitrogen.In a certain range,high temperature significantly facilitate to the mineralization of soill organic nitrogen while the existence of biochar also inhibits of that.

  20. Controls of Soil Spatial Variability in a Dry Tropical Forest

    PubMed Central

    Pulla, Sandeep; Riotte, Jean; Suresh, H. S.; Dattaraja, H. S.; Sukumar, Raman

    2016-01-01

    We examined the roles of lithology, topography, vegetation and fire in generating local-scale (<1 km2) soil spatial variability in a seasonally dry tropical forest (SDTF) in southern India. For this, we mapped soil (available nutrients, Al, total C, pH, moisture and texture in the top 10cm), rock outcrops, topography, all native woody plants ≥1 cm diameter at breast height (DBH), and spatial variation in fire frequency (times burnt during the 17 years preceding soil sampling) in a permanent 50-ha plot. Unlike classic catenas, lower elevation soils had lesser moisture, plant-available Ca, Cu, Mn, Mg, Zn, B, clay and total C. The distribution of plant-available Ca, Cu, Mn and Mg appeared to largely be determined by the whole-rock chemical composition differences between amphibolites and hornblende-biotite gneisses. Amphibolites were associated with summit positions, while gneisses dominated lower elevations, an observation that concurs with other studies in the region which suggest that hillslope-scale topography has been shaped by differential weathering of lithologies. Neither NO3−-N nor NH4+-N was explained by the basal area of trees belonging to Fabaceae, a family associated with N-fixing species, and no long-term effects of fire on soil parameters were detected. Local-scale lithological variation is an important first-order control over soil variability at the hillslope scale in this SDTF, by both direct influence on nutrient stocks and indirect influence via control of local relief. PMID:27100088

  1. Microbial Consumption of Atmospheric Isoprene in a Temperate Forest Soil

    PubMed Central

    Cleveland, C. C.; Yavitt, J. B.

    1998-01-01

    Isoprene (2-methyl-1,3 butadiene) is a low-molecular-weight hydrocarbon emitted in large quantities to the atmosphere by vegetation and plays a large role in regulating atmospheric chemistry. Until now, the atmosphere has been considered the only significant sink for isoprene. However, in this study we performed both in situ and in vitro experiments with soil from a temperate forest near Ithaca, N.Y., that indicate that the soil provides a sink for atmospheric isoprene and that the consumption of isoprene is carried out by microorganisms. Consumption occurred rapidly in field chambers (672.60 ± 30.12 to 2,718.36 ± 86.40 pmol gdw−1 day−1) (gdw is grams [dry weight] of soil; values are means ± standard deviations). Subsequent laboratory experiments confirmed that isoprene loss was due to biological processes: consumption was stopped by autoclaving the soil; consumption rates increased with repeated exposure to isoprene; and consumption showed a temperature response consistent with biological activity (with an optimum temperature of 30°C). Isoprene consumption was diminished under low oxygen conditions (120 ± 7.44 versus 528.36 ± 7.68 pmol gdw−1 day−1 under ambient O2 concentrations) and showed a strong relationship with soil moisture. Isoprene-degrading microorganisms were isolated from the site, and abundance was calculated as 5.8 × 105 ± 3.2 × 105 cells gdw−1. Our results indicate that soil may provide a significant biological sink for atmospheric isoprene. PMID:16349477

  2. The History of Electromagnetic Induction Techniques in Soil Survey

    NASA Astrophysics Data System (ADS)

    Brevik, Eric C.; Doolittle, Jim

    2014-05-01

    Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales.

  3. Remote sensing-based estimation of annual soil respiration at two contrasting forest sites

    DOE PAGESBeta

    Gu, Lianhong; Huang, Ni; Black, T. Andrew; Wang, Li; Niu, Zheng

    2015-11-23

    Soil respiration (Rs), an important component of the global carbon cycle, can be estimated using remotely sensed data, but the accuracy of this technique has not been thoroughly investigated. In this article, we proposed a methodology for the remote estimation of annual Rs at two contrasting FLUXNET forest sites (a deciduous broadleaf forest and an evergreen needleleaf forest).

  4. Plant community influences on soil microfungal assemblages in boreal mixed-wood forests.

    PubMed

    De Bellis, T; Kernaghan, G; Widden, P

    2007-01-01

    We studied the relationships between assemblages of soil microfungi and plant communities in the southern boreal mixed-wood forests of Quebec. Sampling took place in 18,100 m2 plots from an existing research site. Plots were separated into three categories based on dominant overstory tree species: (i) trembling aspen, (ii) white birch and (iii) a mixture of white spruce and balsam fir. Within each plot a 1 m2 subplot was established in which the understory herbaceous layer was surveyed and soil cores were collected. Microfungi were isolated from soil cores with the soil-washing technique and isolates were identified morphologically. To support our morphological identifications DNA sequences were obtained for the most abundant microfungi. The most frequently occurring microfungal species were Penicillium thomii, P. spinulosum, P. janthinellum, Penicillium sp., P. melinii, Trichoderma polysporum, T. viride, T. hamatum, Mortierella ramanniana, Geomyces pannorum, Cylindrocarpon didymum, Mortierella sp. and Mucor hiemalis. Multivariate analyses (redundancy analysis followed by variance partitioning) revealed that most of the variation in microfungal communities was explained by understory plant species composition as opposed to soil chemistry or overstory tree species. In this floristically diverse system saprophytic microfungal assemblages were not correlated with the overstory tree species but were significantly correlated with the main understory herbs, thereby reflecting differences at a smaller spatial scale. PMID:17883027

  5. PH BUFFERING IN FOREST SOIL ORGANIC HORIZONS: RELEVANCE TO ACID PRECIPITATION

    EPA Science Inventory

    Samples of organic surface horizons (Oi, Oe, Oa) from New York State forest soils were equilibrated with 0 to 20 cmol HNO3 Kg(-1) soil in the laboratory by a batch technique designed to simulate reactions of acid precipitation with forest floors. Each organic horizon retained a c...

  6. Different soil respiration responses to litter manipulation in three subtropical successional forests

    NASA Astrophysics Data System (ADS)

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-12-01

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests.

  7. Different soil respiration responses to litter manipulation in three subtropical successional forests

    PubMed Central

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-01-01

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests. PMID:26656136

  8. Different soil respiration responses to litter manipulation in three subtropical successional forests.

    PubMed

    Han, Tianfeng; Huang, Wenjuan; Liu, Juxiu; Zhou, Guoyi; Xiao, Yin

    2015-01-01

    Aboveground litter inputs have been greatly altered by human disturbances and climate change, which have important effects on soil respiration. However, the knowledge of how soil respiration responds to altered litter inputs is limited in tropical and subtropical forests. We conducted an aboveground litterfall manipulation experiment in three successional forests in the subtropics to examine the soil respiration responses to different litter inputs from January 2010 to July 2012. The soil respiration decreased by 35% in the litter exclusion treatments and increased by 77% in the doubled litter additions across all three forests. The reduction in soil respiration induced by the litter exclusion was greatest in the early successional forest, which may be related to a decrease in the soil moisture and shifts in the microbial community. The increase in soil respiration produced by the doubled litter addition was largest in the mature forest, which was most probably due to its relatively high quantity and quality of litterfall. Our results suggest that the effect of reduced litter inputs on the soil respiration lessened with forest succession but that the doubled litter inputs resulted in a stronger priming effect in the mature forest than in the other two forests. PMID:26656136

  9. Spatial heterogeneity of forest soil carbon and nitrogen controls nitrogen transformations and trace gas production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small-scale spatial heterogeneity of soil nitrogen (N) and carbon (C) pools and net transformation processes in forested ecosystems are not well understood. Two forests in central Oregon (Black Butte and Santiam Pass) were used to test the hypothesis that spatial distribution of soil nutrients cont...

  10. Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape.

    PubMed

    Fest, Benedikt; Wardlaw, Tim; Livesley, Stephen J; Duff, Thomas J; Arndt, Stefan K

    2015-11-01

    Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions, mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance, we observed a decrease in soil CH4 uptake. A similar age dependency of potential CH4 oxidation for three soil layers (0.0-0.05, 0.05-0.10, 0.10-0.15 m) could be observed on incubated soils under controlled laboratory conditions. The differences in soil CH4 uptake between forest stands of different age were predominantly driven by differences in soil moisture status, which affected the diffusion of atmospheric CH4 into the soil. The observed soil moisture pattern was likely driven by changes in interception or evapotranspiration with forest age, which have been well described for similar eucalypt forest systems in south-eastern Australia. Our results imply that there is a large amount of variability in CH4 uptake at a landscape scale that can be attributed to stand age and soil moisture differences. An increase in severe WF frequency in response to climate change could potentially increase overall forest soil CH4 sinks. PMID:26087288

  11. Changes in soil carbon stocks in Brazil due to land use: paired site comparisons and a regional pasture soil survey

    NASA Astrophysics Data System (ADS)

    Assad, E. D.; Pinto, H. S.; Martins, S. C.; Groppo, J. D.; Salgado, P. R.; Evangelista, B.; Vasconcellos, E.; Sano, E. E.; Pavão, E.; Luna, R.; Camargo, P. B.; Martinelli, L. A.

    2013-03-01

    In this paper we calculated soil carbon stocks in Brazil using 17 paired sites where soil stocks were determined in native vegetation, pastures and crop-livestock systems (CPS), and in other regional samplings encompassing more than 100 pasture soils, from 6.58° S to 31.53° S, involving three major Brazilian biomes: Cerrado, Atlantic Forest, and the Pampa. The average native vegetation soil carbon stocks at 10 and 30 cm soil depth were equal to approximately 33 and 65 Mg ha-1, respectively. In the paired sites, carbon losses of 7.5 Mg ha-1 and 11.9 Mg ha-1 in CPS systems were observed at 10 cm and 30 cm soil depth averages, respectively. In pasture soils, carbon losses were similar and equal to 8.3 Mg ha-1 and 12.2 Mg ha-1 at 10 cm and 30 cm soil depths, respectively. The average soil δ13C under native vegetation at 10 and 30 cm depth were equal to -25.4‰ and -24.0‰, increasing to -19.6 ‰ and -17.7‰ in CPS, and to -18.9‰, and -18.3‰ in pasture soils, respectively; indicating an increasing contribution of C4 carbon in these agrosystems. In the regional survey of pasture soils, the soil carbon stock at 30 cm was equal to approximately 51 Mg ha-1, with an average δ13C value of -19.6‰. Key controllers of soil carbon stock at pasture sites were sand content and mean annual temperature. Collectively, both could explain approximately half of the variance of soil carbon stocks. When pasture soil carbon stocks were compared with the average soil carbon stocks of native vegetation estimated for Brazilian biomes and soil types by Bernoux et al. (2002) there was a carbon gain of 6.7 Mg ha-1, which is equivalent to a carbon gain of 15% compared to the carbon soil stock of the native vegetation. The findings of this study are consistent with differences found between regional comparisons like our pasture sites and local paired study sites in estimating soil carbon stocks changes due to land use changes.

  12. Contrasting soil thermal responses to fire in Alaskan tundra and boreal forest

    NASA Astrophysics Data System (ADS)

    Jiang, Yueyang; Rocha, Adrian V.; O'Donnell, Jonathan A.; Drysdale, Jessica A.; Rastetter, Edward B.; Shaver, Gaius R.; Zhuang, Qianlai

    2015-02-01

    Recent fire activity throughout Alaska has increased the need to understand postfire impacts on soils and permafrost vulnerability. Our study utilized data and modeling from a permafrost and ecosystem gradient to develop a mechanistic understanding of the short- and long-term impacts of tundra and boreal forest fires on soil thermal dynamics. Fires influenced a variety of factors that altered the surface energy budget, soil moisture, and the organic-layer thickness with the overall effect of increasing soil temperatures and thaw depth. The postfire thickness of the soil organic layer and its impact on soil thermal conductivity was the most important factor determining postfire soil temperatures and thaw depth. Boreal and tundra ecosystems underlain by permafrost experienced smaller postfire soil temperature increases than the nonpermafrost boreal forest from the direct and indirect effects of permafrost on drainage, soil moisture, and vegetation flammability. Permafrost decreased the loss of the insulating soil organic layer, decreased soil drying, increased surface water pooling, and created a significant heat sink to buffer postfire soil temperature and thaw depth changes. Ecosystem factors also played a role in determining postfire thaw depth with boreal forests taking several decades longer to recover their soil thermal properties than tundra. These factors resulted in tundra being less sensitive to postfire soil thermal changes than the nonpermafrost boreal forest. These results suggest that permafrost and soil organic carbon will be more vulnerable to fire as climate warms.

  13. [Effects of forest type on soil organic matter, microbial biomass, and enzyme activities].

    PubMed

    Lu, Shun-bao; Zhou, Xiao-qi; Rui, Yi-chao; Chen, Cheng-rong; Xu, Zhi-hong; Guo, Xiao-min

    2011-10-01

    Taking the typical forest types Pinus elliottii var. elliotttii, Araucaria cunninghamii, and Agathis australis in southern Queensland of Australia as test objects, an investigation was made on the soil soluble organic carbon (SOC) and nitrogen (SON), microbial biomass C (MBC) and N (MBN), and enzyme activities, aimed to understand the effects of forest type on soil quality. In the three forests, soil SOC content was 552-1154 mg kg(-1), soil SON content was 20.11-57.32 mg kg(-1), soil MBC was 42-149 mg kg(-1), soil MBN was 7-35 mg kg(-1), soil chitinase (CAS) activity was 2.96-7.63 microg g(-1) h(-1), soil leucine aminopeptidase (LAP) activity was 0.18-0.46 microg g(-1) d(-1), soil acid phosphatase (ACP) activity was 16.5-29.6 microg g(-1) h(-1), soil alkaline phosphatase (AKP) activity was 0.79-3.42 microg g(-1) h(-1), and soil beta-glucosidase (BG) activity was 3.71-9.93 microg g(-1) h(-1). There was a significant correlation between soil MBC and MBN. Soil SOC content and soil CAS and LAP activities decreased in the order of P. elliottii > A. cunninghamii > A. australis, soil SON content decreased in the order of A. cunninghamii > A. australis > P. elliottii and was significantly higher in A. cunninghamii than in P. elliottii forest (P < 0.05), soil MBC and MBN and AKP activity decreased in the order of A. australis > P. elliottii > A. cunninghamii, and soil ACP and BG activities decreased in the order of P. elliottii > A. australis > A. cunninghamii. Among the test soil biochemical factors, soil MBC, MBN, SON, and LAP had greater effects on the soil quality under the test forest types. PMID:22263459

  14. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest.

    PubMed

    Sun, Hui; Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O

    2016-05-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P< 0.001) and tree species (P< 0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P< 0.04). The availability of soil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera ofAgaricomycotinaidentified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. PMID:26896139

  15. A history of Soil Survey in England and Wales

    NASA Astrophysics Data System (ADS)

    Hallett, S.; Deeks, L.

    2012-04-01

    Early soil mapping in Britain was dominated, as in the USA, by soil texture with maps dating back to the early 1900's identifying surface texture and parent rock materials. Only in the 1920's did Dokuchaev's work in Russia involving soil morphology and the development of the soil profile start to gain popularity, drawing in the influence of climate and topography on pedogenesis. Intentions to create a formal body at this time responsible for soil survey were not implemented and progress remained slow. However, in 1939 definite steps were taken to address this and the soil survey was created. In 1947, its activities were transferred from Bangor to the research branch of the Rothamsted experimental station in Hertfordshire under Professor G.W. Robinson. Soon after, a number of regional offices were also established to act as a link with the National Agricultural Advisory Service. At this time a Pedology Department was established at Rothamsted, focussing on petrological, X-ray, spectrographic and chemical analyses. Although not a Rothamsted Department itself, the Survey did fall under the 'Lawes Agricultural Trust'. A Soil Survey Research Advisory Board was also formed to act as a liaison with the Agricultural Field Council. In Scotland by contrast, soil survey activities became centred on the Macaulay Institute in Aberdeen. Developments in the survey of British soils were accompanied in parallel by the development of soil classification systems. In 1930 a Soils Correlation Committee had been formed to ensure consistency in methods and naming of soil series and to ensure the classification was applied uniformly. In England and Wales the zonal system adopted was similar to that used in the USA, where soil series were named after the location where they were first described. American soil scientists such as Veitch and Lee provided stimulus to the development of mapping methods. In Scotland a differing classification was adopted, being similar to that used in Canada

  16. Soil micronutrients at the plot scale under agricultural and forest soil uses

    NASA Astrophysics Data System (ADS)

    da Silva Días, Rosane; Vidal Vázquez, Eva; dos Santos Batista Bonini, Carolina; Marasca, Indiamara; Paz-Ferreiro, Jorge

    2013-04-01

    Land use practices affect soil properties and nutrient supply. Very limited data are available on the heavy metal extractability in northwest Spain. The aim of this study is to analyze long-term effects of land use on the supply, variability and spatial distribution of soil nutrients, which was undertaken by comparison of a forest and a cultivated stand, rich in organic matter content. The study was carried out in an acid, rich in organic matter soil developed over sediments at the province of Lugo, northwestern of Spain. Adjacent plots with were marked on regular square grids with 2-m spacing. Fe, Mn, Zn and Cu were extracted both by Mehlich-3 and DTPA solutions and determined by ICP-MS. General soil chemical and physical properties were routinely analyzed. In arable land microelement concentration ranges were as follows: Fe (100 and 135 mg/Kg), Mn (7.6 and 21.5 mg/Kg), Zn (0.6 and 3.7 mg/Kg), Cu (0.2 and 0.7 mg/Kg). In forest land, these ranges were: Fe (62 and 309 mg/Kg), Mn (0.2 and 2.1 mg/Kg), Zn (0.2 and 2.9 mg/Kg), Cu (0.1 and 0.2 mg/Kg), Microelement concentrations extracted both with DTPA and Mehlich-3 were higher in the cultivated than in the forest stand, being Fe-DTPA the exception. Coefficients of variation were higher for the microelement content of the soil under forest. Principal component analysis was performed to evaluate associations between extractable microelements and general physico-chemical properties. At the study scale, nutrient management is the main factor affecting the agricultural site, whereas soil-plant interactions are probably driving the higher variation within the forest site. Patterns of spatial variability of the study nutrients at the small plot scale were assessed by geostatistical techniques. Results are discussed in the frame of organic matter decline with conventional tillage and sustainable land use.

  17. Possible method for dissolved organic carbon speciation in forest soils

    NASA Astrophysics Data System (ADS)

    Drabek, O.; Tejnecký, V.; Ash, C.; Hubova, P.; Boruvka, L.

    2013-12-01

    Dissolved organic carbon (DOC) is a natural part of dissolved organic matter and it plays an important role in the biogeochemistry of soil processes. Low Molecular Mass Organic Acids (LMMOA) are an essential part of DOC. These acids play a key role in chemical processes that affect the entire soil environment. Knowing the amount of DOC and the speciation of LMMOA is required for realistic equilibrium modelling of soil chemical processes and transport mechanisms. There have been a number of proposed methods for the quantitative analysis of DOC and for speciation of LMMOA. The first aim of this contribution is to introduce and test a modified spectroscopic method for the determination of water-extractable organic carbon (WEOC) from forest soils. In general this method is based on the oxidization of WEOC by chromium-sulphuric acid. The presented method can be used as an economical alternative to the classical, more financially demanding elemental analysis. However, the main aim is to test the reliability of the method for LMMOA speciation. Ion exchange chromatography (IC) with hydroxide elution has proven to be a useful tool for the determination of LMMOA in many different water-based samples. However, the influence of multivalent cations (often present in environmental samples) on IC results has not yet been sufficiently studied. In order to assess the influence of Al, Fe, Mn, Mg and Ca on the amount of LMMOA determined by IC, an extensive set of model solutions was prepared and immediately analysed by means of IC. Moreover, the influence of pH on determined amounts of LMMOA in model solutions and representative soil aqueous extracts was investigated. These experimental results were compared to expected values and also to results provided by the chemical equilibrium model - PHREEQC. Based on the above listed research, some modifications to the common IC method for LMMOA speciation are presented.

  18. DRAINMOD-FOREST: Integrated Modeling of Hydrology, Soil Carbon and Nitrogen Dynamics, and Plant Growth for Drained Forests.

    PubMed

    Tian, Shiying; Youssef, Mohamed A; Skaggs, R Wayne; Amatya, Devendra M; Chescheir, G M

    2012-01-01

    We present a hybrid and stand-level forest ecosystem model, DRAINMOD-FOREST, for simulating the hydrology, carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. The model was developed by linking DRAINMOD, the hydrological model, and DRAINMOD-N II, the soil C and N dynamics model, to a forest growth model, which was adapted mainly from the 3-PG model. The forest growth model estimates net primary production, C allocation, and litterfall using physiology-based methods regulated by air temperature, water deficit, stand age, and soil N conditions. The performance of the newly developed DRAINMOD-FOREST model was evaluated using a long-term (21-yr) data set collected from an artificially drained loblolly pine ( L.) plantation in eastern North Carolina, USA. Results indicated that the DRAINMOD-FOREST accurately predicted annual, monthly, and daily drainage, as indicated by Nash-Sutcliffe coefficients of 0.93, 0.87, and 0.75, respectively. The model also predicted annual net primary productivity and dynamics of leaf area index reasonably well. Predicted temporal changes in the organic matter pool on the forest floor and in forest soil were reasonable compared to published literature. Both predicted annual and monthly nitrate export were in good agreement with field measurements, as indicated by Nash-Sutcliffe coefficients above 0.89 and 0.79 for annual and monthly predictions, respectively. This application of DRAINMOD-FOREST demonstrated its capability for predicting hydrology and C and N dynamics in drained forests under limited silvicultural practices. PMID:22565258

  19. Fire severity influences the response of soil microbes to a boreal forest fire

    NASA Astrophysics Data System (ADS)

    Holden, Sandra R.; Rogers, Brendan M.; Treseder, Kathleen K.; Randerson, James T.

    2016-03-01

    Wildfire activity is projected to increase in boreal forests as a result of climate warming. The consequences of increased wildfire activity for soil carbon (C) storage in boreal forests may depend on the sensitivity of soil microbes to fire severity, but microbial responses to boreal forest fire severity are not well known. Here, we combine remote sensing of fire severity and field sampling to characterize the response of soil microbial biomass per g soil, microbial respiration of CO2 per g soil, and fungal groups to fire severity in a boreal forest ecosystem. We used remote sensing measurements of differenced normalized burn ratio from Landsat as a measure of fire severity. Our results demonstrate that fire severity controls soil microbial responses to boreal forest fires. In comparison to unburned stands, burned stands had a 52% and 56% reduction in soil microbial biomass and basal respiration, respectively. Within burned stands, we found that microbial biomass and basal respiration significantly declined with increasing fire severity. In addition, mycorrhizal taxa and basidiomycetes displayed particularly low tolerances for severe fire. Although wildfires result in the immediate loss of soil C, our study provides evidence that decreases in microbial biomass and respiration following high severity fires may reduce the capacity of the soil microbial community to decompose soil C over longer time scales. Therefore, models of C cycle responses to climate warming may need to represent the sensitivity of microbial biomass and fungal community composition to fire severity in boreal forests.

  20. Climate change and wildfire influence the methane uptake capacity in Australian eucalypt forest soils

    NASA Astrophysics Data System (ADS)

    Arndt, Stefan; Fest, Benedikt; Hinko-Najera, Nina; Wardlaw, Tim; Livesley, Stephen

    2014-05-01

    Forest ecosystems comprise the largest soil sink for the greenhouse gas methane and climate change and fire can have significant impacts on this important process. We present data from a number of long-term field studies that investigated the impacts of reduced rainfall and fire regimes on soil methane flux in Australian forest systems. Long term soil methane flux measurements with automated chambers indicated that around 90% of soil methane uptake variability in dry- and wet-sclerophyll Eucalyptus obliqua (L. Her.) forests was explained by soil moisture through influencing methane diffusivity. The application of rainfall reduction shelters in the dry-sclerophyll eucalypt forest caused an average reduction of 14.6% in soil volumetric water content but an increase in soil methane uptake of around 38%, again a consequence of increased methane diffusivity. Consequently, the potential reductions in rainfall in large parts of Australia are likely to result in an increase in methane uptake. Wildfire disturbance also altered forest soil methane uptake and here the methane uptake capacity was related to stand age dependent changes in stand structure likely linked to changes in stand water use. Stands that had dryer soils displayed greater methane uptake, indicating that soil methane uptake changes during forest stand development. Wildfire can therefore have significant impacts on landscape level methane uptake.

  1. Comparative study on carbon accumulation in soils under managed and unmanaged forests in Central Balkan Mountains

    NASA Astrophysics Data System (ADS)

    Naydenova, Lora; Zhiyanski, Miglena; Leifeld, Jens

    2014-05-01

    Each soil has a carbon storage capacity, which depends on many factors including type of soil, vegetation, precipitation and temperature. The aim of this work is to compare the carbon accumulation in forest floor layers and mineral soil horizons under managed and unmanaged spruce and beech forest ecosystems developed on Cambisols in Central Balkan Mountains, Bulgaria. We have investigated two managed and two unmanaged forests - pure stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies Karst.). In each experimental site one representative soil profile was prepared with additional 4 sampling profiles for more precise determination of spatial variability of soil characteristic at site level. The forest floor was sampled in 3 repetitions per site, by a plastic frame (25:25 cm). The textural composition of soil, bulk density, coarse fraction content, pH, carbon and nitrogen content were analysed for forest floor layers and soil at different soil depths (0-10 cm, 10-20 cm, 20-30 cm and 30-50 cm). Both European beech and Norway spruce stands had higher accumulation of organic matter in the forest floor and the Ah horizon under unmanaged conditions. When managed, carbon contents tended to be higher in deeper horizons of the mineral soil, probably due to differences in microclimate after cutting. However, the variability in carbon storage was higher in managed sites which may reflect a higher degree of disturbance. Further work will analyse the soil carbon dynamics using radiocarbon as a tracer.

  2. Characterization of soil microbial community dynamics related to C and P cycling along a forest to pasture gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Appalachian Mountains region landscape fragmentation due to farming practices results in areas with gradual blending of forests and pastures ecosystems. Soil nutrient cycling in the open land-forest boundary may be significantly different than in the forest soil or in the pasture soil and th...

  3. [Responses of forest soil carbon pool and carbon cycle to the changes of carbon input].

    PubMed

    Wang, Qing-kui

    2011-04-01

    Litters and plant roots are the main sources of forest soil organic carbon (C). This paper summarized the effects of the changes in C input on the forest soil C pool and C cycle, and analyzed the effects of these changes on the total soil C, microbial biomass C, dissoluble organic C, and soil respiration. Different forests in different regions had inconsistent responses to C input change, and the effects of litter removal or addition and of root exclusion or not differed with tree species and regions. Current researches mainly focused on soil respiration and C pool fractions, and scarce were about the effects of C input change on the changes of soil carbon structure and stability as well as the response mechanisms of soil organisms especially soil fauna, which should be strengthened in the future. PMID:21774335

  4. Responses of Soil Fungal Populations and Communities to the Thinning of Cryptomeria Japonica Forests.

    PubMed

    Lin, Wan-Rou; Wang, Pi-Han; Chen, Wen-Cheng; Lai, Chao-Ming; Winder, Richard Scott

    2016-03-26

    Forest management activities, such as tree thinning, alter forest ecology, including key components of forest ecosystems, including fungal communities. In the present study, we investigate the effects of forest thinning intensity on the populations and structures of fungal soil communities in the Cryptomeria japonica forests of central Taiwan as well as the dynamics of soil fungi communities in these forests after a thinning disturbance. Although the populations of soil fungi significantly increased in the first 6 months after thinning, these increases had subsided by 9 months. This pulse was attributed to a transient increase in the populations of rapid colonizers. A multiple regression analysis positively correlated fungal populations with organic matter content and cellulase activity. Thinning initially provided large amounts of fresh leaves and roots as nutrient-rich substrates for soil fungi. Denaturing gradient gel electrophoresis (DGGE) profiles indicated that soil fungal communities significantly differed among plots with 0% (control), 25%, and 50% tree thinning in the first 21 months post-thinning, with no significant differences being observed after 21 months. The fungal communities of these forest soils also changed with the seasons, and an interactive relationship was detected between seasons and treatments. Seasonal variations in fungal communities were the most pronounced after 50% tree thinning. The results of the present study demonstrate that the soil fungi of Taiwanese C. japonica forests are very sensitive to thinning disturbances, but recover stability after a relatively short period of time. PMID:26903369

  5. Responses of Soil Fungal Populations and Communities to the Thinning of Cryptomeria Japonica Forests

    PubMed Central

    Lin, Wan-Rou; Wang, Pi-Han; Chen, Wen-Cheng; Lai, Chao-Ming; Winder, Richard Scott

    2016-01-01

    Forest management activities, such as tree thinning, alter forest ecology, including key components of forest ecosystems, including fungal communities. In the present study, we investigate the effects of forest thinning intensity on the populations and structures of fungal soil communities in the Cryptomeria japonica forests of central Taiwan as well as the dynamics of soil fungi communities in these forests after a thinning disturbance. Although the populations of soil fungi significantly increased in the first 6 months after thinning, these increases had subsided by 9 months. This pulse was attributed to a transient increase in the populations of rapid colonizers. A multiple regression analysis positively correlated fungal populations with organic matter content and cellulase activity. Thinning initially provided large amounts of fresh leaves and roots as nutrient-rich substrates for soil fungi. Denaturing gradient gel electrophoresis (DGGE) profiles indicated that soil fungal communities significantly differed among plots with 0% (control), 25%, and 50% tree thinning in the first 21 months post-thinning, with no significant differences being observed after 21 months. The fungal communities of these forest soils also changed with the seasons, and an interactive relationship was detected between seasons and treatments. Seasonal variations in fungal communities were the most pronounced after 50% tree thinning. The results of the present study demonstrate that the soil fungi of Taiwanese C. japonica forests are very sensitive to thinning disturbances, but recover stability after a relatively short period of time. PMID:26903369

  6. Degradation of forest soils near an industrial zone

    NASA Astrophysics Data System (ADS)

    Pavlů, Lenka; Drábek, Ondřej; Borůvka, Luboš

    2014-05-01

    Forest soils near industrial zones could be endangered by acid deposition and by contamination by potentially toxic elements (PTEs). The Silesian Beskids represents a feasible example of these two types of forest soils damage. Soils of this area are strongly acid. The surface enrichment by several studied PTEs (Cd, Cu, Pb, Zn) reflects anthropogenic contamination. Moreover, acid character of soils enables presence of dangerous forms of Al. Two forms of all these PTEs were evaluated; potentially mobilized and mobile - the most danger form. Negligible amounts of Cu, Pb, and Al3+ are found in the mobile form. These elements represent just a potential risk for the system. The mobile forms of Cd, Zn, and Mn account for approximately 30 % of potentially mobilized forms in organic horizons. In the mineral horizon, Cd and Zn represent only about 20 % and Mn less than 10 % of potentially mobilized forms. These elements could pose a problem to ecosystem vitality. Cadmium is phytotoxic in small concentrations and its content in mobilized form approaches the critical load. For this reason, Cd could be considered as the most dangerous element in the studied area. While the distribution of mobile Cd is control by cation exchange capacity and hydrolytic acidity in the mineral horizon, stabilization of Cd in potentially mobilized form in organic horizons is enhanced by organic matter quality. A limiting nutrient could be P. Phosphorus plays an important role in the immobilization of toxic Al forms by creation of stable complexes as it was proven by a factor analysis in the H horizon. Negative aspect of this fact is decrease of bioavailability of P for plants. With regard to decreasing emissions, it is important to focus on the stabilization of PTEs deposited into the soil in the past. It is necessary to keep a relatively high quality of organic matter (connected to high CEC), higher pH, and higher nutrient content. This state could be temporarily achieved by the chemical

  7. Natural abundance measurements of 13C indicate increased deep soil carbon mineralization after forest disturbance

    NASA Astrophysics Data System (ADS)

    Diochon, Amanda; Kellman, Lisa

    2008-07-01

    Northern forest soils represent globally important stores of carbon (C), yet there is no consensus about how they are altered by the widespread practice of harvesting that dominates many forested landscapes. Here we present the first study to systematically investigate the utility of δ 13C and C content depth profiles to infer temporal changes in belowground carbon cycling processes following disturbance in a pure C3 ecosystem. We document carbon concentration and δ 13C depth profile enrichment trends consistent with a kinetic fractionation arising from soil organic carbon (SOC) humification across a northern forest chronosequence (1, 15, 45, 80 and 125+ yrs). Reduced soil C storage that coincided with observed soil profile δ 13C-enrichment patterns which intensified following clearcut harvesting, pointed to losses of SOC in the deeper (>20 cm) mineral soil. This study suggests the δ 13C approach may assist in identifying mechanisms responsible for soil C storage changes in disturbed C3 forest ecosystems.

  8. Anthropogenic and geogenic radionuclides content in an undisturbed Slovenian forest soil

    NASA Astrophysics Data System (ADS)

    P, Jankong; L, Mabit; A, Toloza; v, Zupanc

    2010-05-01

    The measurements of natural background radiation and anthropogenic radionuclides in terrestrial environment, especially in soil, have been carried out in many countries for several decades to establish base line data of radiation level. So far, the knowledge of radionuclides concentration levels in Slovenia is limited to a few investigations and the use of anthropogenic 137Cs radionuclide has not yet been used as soil landscape tracer in Slovenia. Therefore, the purposes of this study were: (i) to collect the inventory information of naturally occurring isotope (40K, 226Ra, 232Th, 235U and 238U) and man-made radionuclides (137Cs) as well as their depth/vertical distribution in soil; (ii) to complete radio-ecological survey information in Slovenia and provide information regarding the external dose-rate based on the depth distributions of the gamma emitters in the soil of the study area; and (iii) to establish a reference inventory value of 137Cs fallout in order to prepare for a future investigation to test 137Cs as soil tracer under Slovenian agro-environment. To estimate the natural level of radioactivity and the initial fallout of 137Cs, twenty soil profiles (0-40cm) divided into four increments of 10 cm were collected in an undisturbed forest located in East Slovenia in Šalamenci close to the Hungarian and Austrian borders at the beginning of the Pannonian plains. Depending on the depth increment, the average activity concentration of 137Cs, 40K, 226Ra, 232Th, 235U and 238U were found to be respectively from 0.47 ± 0.27 to 70 ± 33 Bq kg-1, from 535 ± 16 to 703 ± 20 Bq kg-1, from 51 ± 3 to 49 ± 2 Bq kg-1, from 54 ± 6 to 62 ± 4 Bq kg-1, from 7.8 ± 0.8 to 8.1 ± 0.3 Bq kg-1and from 58 ± 22 to 68 ± 27 Bq kg-1. On average the top soil mass activity of 40K is 7 to 8 times higher than that of 137Cs and the depth distribution of this isotope, instead of showing a constant amount along the soil profile, presents an increase with depth. The external gamma

  9. Production and retention of methylmercury in inundated boreal forest soils.

    PubMed

    Rolfhus, Kristofer R; Hurley, James P; Bodaly, Richard A Drew; Perrine, Gregory

    2015-03-17

    The Flooded Uplands Dynamics Experiment (FLUDEX) was an ecosystem-scale study examining the production of methylmercury (MeHg) and greenhouse gases from reservoirs constructed on an upland boreal forest landscape in order to quantify their dependence upon carbon stores. We detail the within-reservoir production and storage of MeHg before, during, and nine years after the experiment. The reservoirs were net MeHg producers during the first two years of flooding, and net demethylating systems afterward. During years 1-3, a rapid pulse of MeHg and total Hg was observed in floodwater, followed by substantial increases in MeHg in seston and sediment. Resampling of the dry reservoirs nine years after the experiment ended indicated that organic soil MeHg was still 8 to 52-fold higher than preflood conditions, and averaged 86% of the levels recorded at the end of the third flooding year. Both total Hg and MeHg retention in soil were a strong function of organic carbon content. The time scale of soil MeHg retention may help explain the decadal time lag frequently observed for the decrease of piscivorous fish Hg concentrations in new reservoirs. Predicted extreme precipitation events associated with climate change may serve to make landscapes more susceptible to this process. PMID:25668143

  10. 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

  11. Quantification of soil fauna metabolites and dead mass as humification sources in forest soils

    NASA Astrophysics Data System (ADS)

    Chertov, O. G.

    2016-01-01

    The analysis of publications on soil food webs (FWs) allowed calculation of the contents of soil fauna metabolites and dead mass, which can serve as materials for humification. Excreta production of FWmicrofauna reaches 570 kg/ha annually, but the liquid excreta of protozoa and nematodes compose about 25%. The soil fauna dead mass can be also maximally about 580 kg/ha per year. However, up to 70% of this material is a dead mass of bacteria, protozoa, and nematodes. The undecomposed forest floor (L) has low values of these metabolites in comparison with the raw humus organic layer (F + H). The mass of these metabolites is twice lower in Ah. Theoretical assessment of earthworms' role in SOM formation shows that the SOM amount in fresh coprolites can be 1.4 to 4.5-fold higher than SOM in the bulk soil in dependence on food assimilation efficiency, the soil: litter ratio in the earthworms' ration, and SOM quantity in the bulk soil. Excreta production varies from 0.2 to 1.9% of the total SOM pool annually, including 0.15-1.5% of excrements of arthropods and enchytraeidae, but the amount of arthropods' dead mass comprises 0.2-0.4%. The calculated values of the SOM increase due to earthworms' coprolites are of the same order (0.9-2.7% of SOM pool annually). These values of SOM-forming biota metabolites and dead mass are close to the experimental and simulated data on labile and stable SOM fractions decomposition in forest soils (about 2% annually). Therefore, these biota's products can play a role to restock SOM decrease due to mineralization.

  12. [Soil and forest structure in the Colombian Amazon].

    PubMed

    Calle-Rendón, Bayron R; Moreno, Flavio; Cárdenas López, Dairon

    2011-09-01

    Forests structural differences could result of environmental variations at different scales. Because soils are an important component of plant's environment, it is possible that edaphic and structural variables are associated and that, in consequence, spatial autocorrelation occurs. This paper aims to answer two questions: (1) are structural and edaphic variables associated at local scale in a terra firme forest of Colombian Amazonia? and (2) are these variables regionalized at the scale of work? To answer these questions we analyzed the data of a 6ha plot established in a terra firme forest of the Amacayacu National Park. Structural variables included basal area and density of large trees (diameter > or = 10cm) (Gdos and Ndos), basal area and density of understory individuals (diameter < 10cm) (Gsot and Nsot) and number of species of large trees (sp). Edaphic variables included were pH, organic matter, P, Mg, Ca, K, Al, sand, silt and clay. Structural and edaphic variables were reduced through a principal component analysis (PCA); then, the association between edaphic and structural components from PCA was evaluated by multiple regressions. The existence of regionalization of these variables was studied through isotropic variograms, and autocorrelated variables were spatially mapped. PCA found two significant components for structure, corresponding to the structure of large trees (G, Gdos, Ndos and sp) and of small trees (N, Nsot and Gsot), which explained 43.9% and 36.2% of total variance, respectively. Four components were identified for edaphic variables, which globally explained 81.9% of total variance and basically represent drainage and soil fertility. Regression analyses were significant (p < 0.05) and showed that the structure of both large and small trees is associated with greater sand contents and low soil fertility, though they explained a low proportion of total variability (R2 was 4.9% and 16.5% for the structure of large trees and small tress

  13. Impact of Logging and Forest Conversion to Oil Palm Plantations on Soil Bacterial Communities in Borneo

    PubMed Central

    Lee-Cruz, Larisa; Edwards, David P.; Tripathi, Binu M.

    2013-01-01

    Tropical forests are being rapidly altered by logging and cleared for agriculture. Understanding the effects of these land use changes on soil bacteria, which constitute a large proportion of total biodiversity and perform important ecosystem functions, is a major conservation frontier. Here we studied the effects of logging history and forest conversion to oil palm plantations in Sabah, Borneo, on the soil bacterial community. We used paired-end Illumina sequencing of the 16S rRNA gene, V3 region, to compare the bacterial communities in primary, once-logged, and twice-logged forest and land converted to oil palm plantations. Bacteria were grouped into operational taxonomic units (OTUs) at the 97% similarity level, and OTU richness and local-scale α-diversity showed no difference between the various forest types and oil palm plantations. Focusing on the turnover of bacteria across space, true β-diversity was higher in oil palm plantation soil than in forest soil, whereas community dissimilarity-based metrics of β-diversity were only marginally different between habitats, suggesting that at large scales, oil palm plantation soil could have higher overall γ-diversity than forest soil, driven by a slightly more heterogeneous community across space. Clearance of primary and logged forest for oil palm plantations did, however, significantly impact the composition of soil bacterial communities, reflecting in part the loss of some forest bacteria, whereas primary and logged forests did not differ in composition. Overall, our results suggest that the soil bacteria of tropical forest are to some extent resilient or resistant to logging but that the impacts of forest conversion to oil palm plantations are more severe. PMID:24056463

  14. Effects of precipitation on soil acid phosphatase activity in three successional forests in southern China

    NASA Astrophysics Data System (ADS)

    Huang, W.; Liu, J.; Zhou, G.; Zhang, D.; Deng, Q.

    2011-07-01

    Phosphorus (P) is often a limiting nutrient for plant growth in tropical and subtropical forests. Global climate change has led to alterations in precipitation in the recent years, which inevitably influences P cycling. Soil acid phosphatase plays a vital role in controlling P mineralization, and its activity reflects the capacity of organic P mineralization potential in soils. In order to study the effects of precipitation on soil acid phosphatase activity, an experiment with precipitation treatments (no precipitation, natural precipitation and doubled precipitation) in three successional forests in southern China was carried out. The three forests include Masson pine forest (MPF), coniferous and broad-leaved mixed forest (MF) and monsoon evergreen broad-leaved forest (MEBF). Results showed that driven by seasonality of precipitation, changes in soil acid phosphatase activities coincided with the seasonal climate pattern, with significantly higher values in the wet season than in the dry season. Soil acid phosphatase activities were closely linked to forest successional stages, with enhanced values in the later stages of forest succession. In the dry season, soil acid phosphatase activities in the three forests showed a rising trend with increasing precipitation treatments. In the wet season, soil acid phosphatase activity was depressed by no precipitation treatment in the three forests. However, doubled precipitation treatment exerted a significantly negative effect on it only in MEBF. These results indicate that the potential transformation rate of organic P might be more dependent on water in the dry season than in the wet season. A decrease in organic P turnover would occur in the three forests if there was a drought in a whole year in the future. More rainfall in the wet season would also be adverse to organic P turnover in MEBF due to its high soil moisture.

  15. Rapid Assessment of U.S. Forest and Soil Organic Carbon Storage and Forest Biomass Carbon-Sequestration Capacity

    USGS Publications Warehouse

    Sundquist, Eric T.; Ackerman, Katherine V.; Bliss, Norman B.; Kellndorfer, Josef M.; Reeves, Matt C.; Rollins, Matthew G.

    2009-01-01

    This report provides results of a rapid assessment of biological carbon stocks and forest biomass carbon sequestration capacity in the conterminous United States. Maps available from the U.S. Department of Agriculture are used to calculate estimates of current organic carbon storage in soils (73 petagrams of carbon, or PgC) and forest biomass (17 PgC). Of these totals, 3.5 PgC of soil organic carbon and 0.8 PgC of forest biomass carbon occur on lands managed by the U.S. Department of the Interior (DOI). Maps of potential vegetation are used to estimate hypothetical forest biomass carbon sequestration capacities that are 3-7 PgC higher than current forest biomass carbon storage in the conterminous United States. Most of the estimated hypothetical additional forest biomass carbon sequestration capacity is accrued in areas currently occupied by agriculture and development. Hypothetical forest biomass carbon sequestration capacities calculated for existing forests and woodlands are within +or- 1 PgC of estimated current forest biomass carbon storage. Hypothetical forest biomass sequestration capacities on lands managed by the DOI in the conterminous United States are 0-0.4 PgC higher than existing forest biomass carbon storage. Implications for forest and other land management practices are not considered in this report. Uncertainties in the values reported here are large and difficult to quantify, particularly for hypothetical carbon sequestration capacities. Nevertheless, this rapid assessment helps to frame policy and management discussion by providing estimates that can be compared to amounts necessary to reduce predicted future atmospheric carbon dioxide levels.

  16. The effect of increasing salinity and forest mortality on soil nitrogen and phosphorus mineralization in tidal freshwater forested wetlands

    USGS Publications Warehouse

    Noe, Gregory B.; Krauss, Ken W.; Lockaby, B. Graeme; Conner, William H.; Hupp, Cliff R.

    2013-01-01

    Tidal freshwater wetlands are sensitive to sea level rise and increased salinity, although little information is known about the impact of salinification on nutrient biogeochemistry in tidal freshwater forested wetlands. We quantified soil nitrogen (N) and phosphorus (P) mineralization using seasonal in situ incubations of modified resin cores along spatial gradients of chronic salinification (from continuously freshwater tidal forest to salt impacted tidal forest to oligohaline marsh) and in hummocks and hollows of the continuously freshwater tidal forest along the blackwater Waccamaw River and alluvial Savannah River. Salinification increased rates of net N and P mineralization fluxes and turnover in tidal freshwater forested wetland soils, most likely through tree stress and senescence (for N) and conversion to oligohaline marsh (for P). Stimulation of N and P mineralization by chronic salinification was apparently unrelated to inputs of sulfate (for N and P) or direct effects of increased soil conductivity (for N). In addition, the tidal wetland soils of the alluvial river mineralized more P relative to N than the blackwater river. Finally, hummocks had much greater nitrification fluxes than hollows at the continuously freshwater tidal forested wetland sites. These findings add to knowledge of the responses of tidal freshwater ecosystems to sea level rise and salinification that is necessary to predict the consequences of state changes in coastal ecosystem structure and function due to global change, including potential impacts on estuarine eutrophication.

  17. Climate response of the soil nitrogen cycle in three forest types of a headwater Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    Lupon, Anna; Gerber, Stefan; Sabater, Francesc; Bernal, Susana

    2015-05-01

    Future changes in climate may affect soil nitrogen (N) transformations, and consequently, plant nutrition and N losses from terrestrial to stream ecosystems. We investigated the response of soil N cycling to changes in soil moisture, soil temperature, and precipitation across three Mediterranean forest types (evergreen oak, beech, and riparian) by fusing a simple process-based model (which included climate modifiers for key soil N processes) with measurements of soil organic N content, mineralization, nitrification, and concentration of ammonium and nitrate. The model describes sources (atmospheric deposition and net N mineralization) and sinks (plant uptake and hydrological losses) of inorganic N from and to the 0-10 cm soil pool as well as net nitrification. For the three forest types, the model successfully recreated the magnitude and temporal pattern of soil N processes and N concentrations (Nash-Sutcliffe coefficient = 0.49-0.96). Changes in soil water availability drove net N mineralization and net nitrification at the oak and beech forests, while temperature and precipitation were the strongest climatic factors for riparian soil N processes. In most cases, net N mineralization and net nitrification showed a different sensitivity to climatic drivers (temperature, soil moisture, and precipitation). Our model suggests that future climate change may have a minimal effect on the soil N cycle of these forests (<10% change in mean annual rates) because positive warming and negative drying effects on the soil N cycle may counterbalance each other.

  18. Thermal Characteristics and Bacterial Diversity of Forest Soil in the Haean Basin of Korea

    PubMed Central

    Kim, Heejung; Lee, Jin-Yong; Lee, Kang-Kun

    2014-01-01

    To predict biotic responses to disturbances in forest environments, it is important to examine both the thermophysical properties of forest soils and the diversity of microorganisms that these soils contain. To predict the effects of climate change on forests, in particular, it is essential to understand the interactions between the soil surface, the air, and the biological diversity in the soil. In this study, the temperature and thermal properties of forest soil at three depths at a site in the Haean basin of Korea were measured over a period of four months. Metagenomic analyses were also carried out to ascertain the diversity of microorganisms inhabiting the soil. The thermal diffusivity of the soil at the study site was 5.9 × 10−8 m2·s−1. The heat flow through the soil resulted from the cooling and heating processes acting on the surface layers of the soils. The heat productivity in the soil varied through time. The phylum Proteobacteria predominated at all three soil depths, with members of Proteobacteria forming a substantial fraction (25.64 to 39.29%). The diversity and richness of microorganisms in the soil were both highest at the deepest depth, 90 cm, where the soil temperature fluctuation was the minimum. PMID:25431780

  19. Forest Age and Plant Species Composition Determine the Soil Fungal Community Composition in a Chinese Subtropical Forest

    PubMed Central

    Trogisch, Stefan; Both, Sabine; Scholten, Thomas; Bruelheide, Helge; Buscot, François

    2013-01-01

    Fungal diversity and community composition are mainly related to soil and vegetation factors. However, the relative contribution of the different drivers remains largely unexplored, especially in subtropical forest ecosystems. We studied the fungal diversity and community composition of soils sampled from 12 comparative study plots representing three forest age classes (Young: 10–40 yrs; Medium: 40–80 yrs; Old: ≥80 yrs) in Gutianshan National Nature Reserve in South-eastern China. Soil fungal communities were assessed employing ITS rDNA pyrotag sequencing. Members of Basidiomycota and Ascomycota dominated the fungal community, with 22 putative ectomycorrhizal fungal families, where Russulaceae and Thelephoraceae were the most abundant taxa. Analysis of similarity showed that the fungal community composition significantly differed among the three forest age classes. Forest age class, elevation of the study plots, and soil organic carbon (SOC) were the most important factors shaping the fungal community composition. We found a significant correlation between plant and fungal communities at different taxonomic and functional group levels, including a strong relationship between ectomycorrhizal fungal and non-ectomycorrhizal plant communities. Our results suggest that in subtropical forests, plant species community composition is the main driver of the soil fungal diversity and community composition. PMID:23826151

  20. Effects of soil moisture and temperature on NO, NO2, and N2O emissions from European forest soils

    NASA Astrophysics Data System (ADS)

    Schindlbacher, Andreas; Zechmeister-Boltenstern, Sophie; Butterbach-Bahl, Klaus

    2004-09-01

    Emissions of NO, NO2, and N2O to the atmosphere were measured with a fully automated laboratory system from undisturbed soil columns obtained from five different temperate and one boreal forest sites. The soils were chosen to cover a transect through Europe, sandy and loamy textures, and different atmospheric nitrogen deposition rates. In a two-factorial experimental design, soil cores were kept under varying conditions with respect to temperature (range 5-20°C) and soil moisture (range 0-300 kPa). The combination of soil temperature and soil moisture could explain a better part of variations in NO (up to 74%) and N2O (up to 86%) emissions for individual soils, but average emissions differed significantly between various forest soils. Generally, NO and N2O were emitted from all soils except from the boreal pine forest soil, where NO was consumed. NO emissions from the German spruce forest receiving highest yearly nitrogen inputs of >35 kg ha-1 yr-1 ranged from 1.3 to 608.9 μg NO-N m-2 h-1 and largely exceeded emissions from other soils. Average N2O emissions from this soil tended also to be highest (171.7 ± 42.2 μg N2O-N m-2 h-1), but did not differ significantly from other soils. NO2 deposition occurred in all soils and strongly correlated to NO emissions. NO and N2O emissions showed a positive exponential relationship to soil temperature. With activation energies between 57 and 133 kJ mol-1, N2O emissions from the various soils responded more uniformely to temperature than NO emissions with 41 and 199 kJ mol-1. The two Austrian beech forest soils showed exceptionally high activation energies for NO emissions, which might be attributed to chemodenitrification. N2O emissions increased with increasing water filled pore space (WFPS) or decreasing water tension, respectively. Maximal N2O emissions were measured between 80 and 95% WFPS or 0 kPa water tension. Optimal moisture for NO emission differed significantly between the soils, and ranged between 15% WFPS in

  1. Changes to Stream Water and Soil Temperature Regimes Pre and Post Forest Harvesting in Low Order Boreal Forest Watersheds.

    NASA Astrophysics Data System (ADS)

    Allan, C. J.; Najaf, P.; Mackereth, R.; Steedman, R.

    2014-12-01

    Soil and stream water temperatures were logged at 15 minute intervals (1995-2008) pre and post logging at four intensively monitored zero order boreal forest watersheds in NW Ontario, Canada. Trends in post logging changes to daily average, maximum and diurnal ranges in stream water and soil temperatures are presented. Changes to the soil temperature regime were found to be spatially variable and dependent upon aspect, hill slope position and soil moisture regime. In general, soil temperature displayed a hysteretic behavior in relation to reference sites during the post logging period with significantly warmer spring and summer temperatures and similar autumn temperatures. Stream water temperature appeared to be controlled by post logging surface soil temperatures (0-15 cm) as opposed to deeper (30-40 cm) soil temperatures during the pretreatment period. Results are compared to previous studies and implications for soil microbial processes and stream benthic communities are highlighted.

  2. Effects of fire and harvest on soil respiration in a mixed-conifer forest

    NASA Astrophysics Data System (ADS)

    Dore, S.; Fry, D.; Stephens, S.

    2012-12-01

    Forest ecosystems, and in particular forest soils, constitute a major reservoir of global terrestrial carbon and soil respiration is the largest carbon loss from these ecosystems. Disturbances can affect soil respiration, causing physical and chemical changes in soil characteristics, adding both, above and belowground necromass, and changing microclimatic conditions. This could signify an important and long term carbon loss, even higher than the carbon directly removed by the harvest or during fire. These losses need to be included when quantifying the net carbon balance of forests. We measured the impacts of prescribed fire and clear-cut tree harvest on soil respiration in a mixed-conifer forest in the central Sierra Nevada. The prescribed fire treatment was implemented in 2002 and again in 2009. Four areas were clear-cut harvested in 2010. In half of these units the soils were mechanically ripped to reduce soil compaction, a common practice in the Sierra Nevada industrial forest lands. Soil respiration was measured using two different techniques: the chamber method and the gradient method. Soil respiration was affected by treatments in two different ways. First, treatments changed soil temperature and soil water content, the main abiotic factors controlling soil respiration. The clear cut and the prescribed fire treatments created higher maximum soil temperature and more available soil water content, environmental conditions favorable to soil respiration. However, the loss of trees and thus fine roots, and the decrease of soil litter and organic layers, because of their combustion or removal, had a negative effect on soil respiration that was stronger than the positive effect due to more favorable post disturbance environmental conditions. Soil respiration rates remained steady 1-2 years after treatments and no increase or spikes of soil respiration were measured after treatments. Continuous measurements of CO2 concentrations at different soil depths improved our

  3. Soil Carbon Response to Soil Warming and Nitrogen Deposition in a Temperate Deciduous Forest

    NASA Astrophysics Data System (ADS)

    Parton, W. J.; Savage, K. E.; Davidson, E. A.; Trumbore, S.; Frey, S. D.

    2011-12-01

    While estimates of global soil C stocks vary widely, it is clear that soils store several times more C than is present in the atmosphere as CO2, and a significant fraction of soil C stocks are potentially subject to faster rates of decomposition in a warmer world. We address, through field based studies and modeling efforts, whether manipulations of soil temperature and nitrogen supply affect the magnitude and relative age of soil C substrates that are respired from a temperate deciduous forest located at Harvard Forest, MA. A soil warming and nitrogen addition experiment was initiated at the Harvard Forest in 2006. The experiment consists of six replicates of four treatments, control, heated, nitrogen, and heat+nitrogen addition. Soil temperatures in the heated plots are continuously elevated 5 oC above ambient and for the fertilized plots an aqueous solution of NH4NO3 is applied at a rate of 5 g m-2 yr-1. Soil C efflux from these plots was measured (n=24, 6 per treatment) biweekly throughout the year, while 14CO2 was measured (3 samples per treatment) several times during the summer months from 2006-2010. Following treatment, observed rates of annual C efflux increased under heating and nitrogen additions with heating treatments showing the greatest increase in respired C. The difference between control and treatments was greatest during the initial year following treatment; however this difference decreased in the subsequent 3 years of measurement. The plots designated for heating had a higher 14C signature from CO2 efflux prior to the heating (presumably due to spatial heterogeneity). However, because of the high spatial heterogeneity in measured 14C among treatments, no significant difference among treatments was observed from 2006 through 2010. Long term datasets (1995 through 2010) of soil C stocks, radiocarbon content, and CO2 efflux were used to parameterize the ForCent model for Harvard forest. The model was then run with the same treatment parameters as

  4. Soil erosion after forest fires in the Valencia region

    NASA Astrophysics Data System (ADS)

    González-Pelayo, Óscar; Keizer, Jan Jacob; Cerdà, Artemi

    2014-05-01

    Soil erosion after forest fire is triggered by the lack of vegetation cover and the degradation of the physical, biological and chemical properties (Martí et al., 2012; Fernández et al., 2012; Guénon, 2013). Valencia region belongs to the west Mediterranean basin ("Csa", Köppen climate classification), with drought summer periods that enhance forest fire risk. The characteristics of the climate, lithology and land use history makes this region more vulnerable to soil erosion. In this area, fire recurrence is being increased since late 50s (Pausas, 2004) and post-fire erosion studies became more popular from 80's until nowadays (Cerdá and Mataix-Solera, 2009). Research in Valencia region has contributed significantly to a better understanding of the effect of spatial and temporal scale on runoff and sediment yield measurements. The main achievements concerns: a) direct measurement of erosion rates under a wide range of methodologies (natural vs simulated rainfall, open vs closed plots); from micro- to meso-plot and catchment scale in single (Rubio et al., 1994; Cerdà et al., 1995; Cerdà 1998a; 1998b; Llovet et al., 1998; Cerdà, 2001; Calvo-Cases et al., 2003; Andreu et al., 2001; Mayor et al., 2007; Cerdà and Doerr, 2008) and multiples fires (Campo et al., 2006; González-Pelayo et al., 2010a). Changes in soil properties (Sanroque et al., 1985; Rubio et al., 1997; Boix-Fayós, 1997; Gimeno-Garcia et al., 2000; Guerrero et al., 2001; Mataix-Solera et al., 2004; González-Pelayo et al., 2006; Arcenegui et al., 2008; Campo et al., 2008; Bodí et al., 2012), in post-fire vegetation patterns (Gimeno-García et al., 2007) and, studies on mitigation strategies (Bautista et al., 1996; Abad et al., 2000). b) Progress to understanding post-fire erosion mechanism and sediment movement (Boix-Fayós et al., 2005) by definition of thresholds for sediment losses; fire severity, slope angle, bedrock, rain characteristics, vegetation pattern and ecosystem resilience (Mayor

  5. Fine root dynamics for forests on contrasting soils in the Colombian Amazon

    NASA Astrophysics Data System (ADS)

    Jiménez, E. M.; Moreno, F. H.; Peñuela, M. C.; Patiño, S.; Lloyd, J.

    2009-12-01

    It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots) should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm) by two methods: (1) ingrowth cores and, (2) sequential soil coring, during 2.2 years in two lowland forests growing on different soils types in the Colombian Amazon. Differences of soil resources were defined by the type and physical and chemical properties of soil: a forest on clay loam soil (Endostagnic Plinthosol) at the Amacayacu National Natural Park and, the other on white sand (Ortseinc Podzol) at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that the standing crop fine root mass and the production was significantly different between soil depths (0-10 and 10-20 cm) and also between forests. The loamy sand forest allocated more carbon to fine roots than the clay loam forest with the production in loamy sand forest twice (mean±standard error=2.98±0.36 and 3.33±0.69 Mg C ha-1 yr-1, method 1 and 2, respectively) as much as for the more fertile loamy soil forest (1.51±0.14, method 1, and from 1.03±0.31 to 1.36±0.23 Mg C ha-1 yr-1, method 2). Similarly, the average of standing crop fine root mass was higher in the white-sands forest (10.94±0.33 Mg C ha-1) as compared to the forest on the more fertile soil (from 3.04±0.15 to 3.64±0.18 Mg C ha-1). The standing crop fine root mass also showed a temporal pattern related to rainfall, with the production of fine roots decreasing substantially in the dry period of the year 2005. These results suggest that soil resources may play an important role in patterns of carbon allocation to the production of fine roots in these forests as the proportion of carbon allocated to above- and below-ground organs is different between forest types. Thus, a trade-off between above- and below-ground growth seems to exist

  6. Soil organic matter quantity and quality shape microbial community compositions of subtropical broadleaved forests.

    PubMed

    Ding, Junjun; Zhang, Yuguang; Wang, Mengmeng; Sun, Xin; Cong, Jing; Deng, Ye; Lu, Hui; Yuan, Tong; Van Nostrand, Joy D; Li, Diqiang; Zhou, Jizhong; Yang, Yunfeng

    2015-10-01

    As two major forest types in the subtropics, broadleaved evergreen and broadleaved deciduous forests have long interested ecologists. However, little is known about their belowground ecosystems despite their ecological importance in driving biogeochemical cycling. Here, we used Illumina MiSeq sequencing targeting 16S rRNA gene and a microarray named GeoChip targeting functional genes to analyse microbial communities in broadleaved evergreen and deciduous forest soils of Shennongjia Mountain of Central China, a region known as 'The Oriental Botanic Garden' for its extraordinarily rich biodiversity. We observed higher plant diversity and relatively richer nutrients in the broadleaved evergreen forest than the deciduous forest. In odds to our expectation that plant communities shaped soil microbial communities, we found that soil organic matter quantity and quality, but not plant community parameters, were the best predictors of microbial communities. Actinobacteria, a copiotrophic phylum, was more abundant in the broadleaved evergreen forest, while Verrucomicrobia, an oligotrophic phylum, was more abundant in the broadleaved deciduous forest. The density of the correlation network of microbial OTUs was higher in the broadleaved deciduous forest but its modularity was smaller, reflecting lower resistance to environment changes. In addition, keystone OTUs of the broadleaved deciduous forest were mainly oligotrophic. Microbial functional genes associated with recalcitrant carbon degradation were also more abundant in the broadleaved deciduous forests, resulting in low accumulation of organic matters. Collectively, these findings revealed the important role of soil organic matter in shaping microbial taxonomic and functional traits. PMID:26363284

  7. Altered soil organic carbon stability in eastern deciduous forest: interplay between forest successional Stage and invasive earthworm activity

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Filley, T. R.; McCormick, M.; Szlavecz, K. A.

    2012-12-01

    Detritivore -mediated decomposition and incorporation of aboveground litter is an important processes in soil carbon cycle of forest ecosystems that can be a major control on the proportion of stable and unstable soil carbon pools. We investigated how earthworm activity interacts with litter type to alter the stability of soil organic carbon (SOC) in an eastern deciduous successional forest within at the Smithsonian Environmental Research Center (SERC). Soil C and N content and chemistry (lignin and fatty acids) among particulate and mineral-bound fractions was shifted after 5 years of litter (wood and leaf) addition but with significant differences among the forest successional stages and with earthworm activity. Results from a 6 month laboratory incubation (25°C and 15°C) of bulk soil samples taken from the treatments and incubated at 25°C and 15°C demonstrate that litter addition type and earthworm activity interacted to control the proportion of labile and stable carbon. Specifically, the labile C pools in double wood and control treatments were highest in young successional forest with higher earthworm activity. However, in the double leaf treatment, the labile C pool was higher in old successional forests with less worm activity. In general, the stable C pool, released after one month, was higher in old successional forests for all three treatments. The difference of the stable pool between young and old successional forest was the largest with double wood treatment, followed by control treatment and the lowest with double leaf treatment. In summary, wood treatment shifted SOC pool to relatively more stable pool in old successional forests decreasing labile C pool but not the young sites. While double leaf treatment increased the labile pool in old forests but in young successional forests, SOC shifted to relatively more stable pool by decreasing the labile pool and increasing the stable pool. This result indicates that the type of aboveground litter

  8. Survey of methods for soil moisture determination

    NASA Technical Reports Server (NTRS)

    Schmugge, T. J.; Jackson, T. J.; Mckim, H. L.

    1979-01-01

    Existing and proposed methods for soil moisture determination are discussed. These include: (1) in situ investigations including gravimetric, nuclear, and electromagnetic techniques; (2) remote sensing approaches that use the reflected solar, thermal infrared, and microwave portions of the electromagnetic spectrum; and (3) soil physics models that track the behavior of water in the soil in response to meteorological inputs (precipitation) and demands (evapotranspiration). The capacities of these approaches to satisfy various user needs for soil moisture information vary from application to application, but a conceptual scheme for merging these approaches into integrated systems to provide soil moisture information is proposed that has the potential for meeting various application requirements.

  9. Soil C Quantification and CO2 Efflux in the Boreal Forest, James Bay, Canada.

    NASA Astrophysics Data System (ADS)

    Banville, J. L.; Garneau, M.; Paré, D.

    2007-12-01

    The Boreal forest contains about 50% of the total organic carbon stored in forest ecosystems, and in these forests, the largest reservoir is the soil, because low temperatures promote net accumulation of organic C (Dioumaeva et al. 2003) These types of forest covers nearly 3 million km2, consequently, it can significantly influence the global carbon cycle (Kurz et al. 2002). Forest ecosystems take up atmospheric CO2 by converting into organic C through photosynthesis. Various physico-chemical and microbial properties of boreal forest soils regulating soil organic C (SOC) accumulation and decomposition are poorly understood. In this study, we present data on the quantity and quality of SOC in five different boreal forest types in the northern Quebec. The aims of our research are to (1) determine the role of several site-specfic variables influencing carbon storage such as forest stand composition, age, litter quality and production rate, as well as soil properties such as chemistry, drainage and texture, and (2) determine labile vs recalcitrant fractions of the SOC carbon as well as reactivity to temperature as related to the site characteristics described above. Results showed that litterfall, soil drainage class, and clay contents correlate significantly with the SOC contents in different forest types. Forest stand age and litter fall have a bearing on SOC accumulation rates. Forest type does not seem to affect SOC accumulation. Moreover, results suggest that drainage is a main driver of SOC accumulation. This project is still underway and we are currently measuring SOC mineralization rates under variable soil temperature regimes (2, 14 and 29 oC) in vitro to determine site specific difference in SOC quality and reactivity to temperature across forest stand types.

  10. Responses of soil fungi to logging and oil palm agriculture in Southeast Asian tropical forests.

    PubMed

    McGuire, K L; D'Angelo, H; Brearley, F Q; Gedallovich, S M; Babar, N; Yang, N; Gillikin, C M; Gradoville, R; Bateman, C; Turner, B L; Mansor, P; Leff, J W; Fierer, N

    2015-05-01

    Human land use alters soil microbial composition and function in a variety of systems, although few comparable studies have been done in tropical forests and tropical agricultural production areas. Logging and the expansion of oil palm agriculture are two of the most significant drivers of tropical deforestation, and the latter is most prevalent in Southeast Asia. The aim of this study was to compare soil fungal communities from three sites in Malaysia that represent three of the most dominant land-use types in the Southeast Asia tropics: a primary forest, a regenerating forest that had been selectively logged 50 years previously, and a 25-year-old oil palm plantation. Soil cores were collected from three replicate plots at each site, and fungal communities were sequenced using the Illumina platform. Extracellular enzyme assays were assessed as a proxy for soil microbial function. We found that fungal communities were distinct across all sites, although fungal composition in the regenerating forest was more similar to the primary forest than either forest community was to the oil palm site. Ectomycorrhizal fungi, which are important associates of the dominant Dipterocarpaceae tree family in this region, were compositionally distinct across forests, but were nearly absent from oil palm soils. Extracellular enzyme assays indicated that the soil ecosystem in oil palm plantations experienced altered nutrient cycling dynamics, but there were few differences between regenerating and primary forest soils. Together, these results show that logging and the replacement of primary forest with oil palm plantations alter fungal community and function, although forests regenerating from logging had more similarities with primary forests in terms of fungal composition and nutrient cycling potential. Since oil palm agriculture is currently the mostly rapidly expanding equatorial crop and logging is pervasive across tropical ecosystems, these findings may have broad applicability

  11. Delivering solutions to questions regarding soil change— examples from USDA and the National Cooperative Soil Survey

    NASA Astrophysics Data System (ADS)

    Levin, Maxine J.; Andrews, Susan; Robotham, Michael; Brown, Joel; Vasilas, Lenore; Hoover, David

    2015-07-01

    The US National Cooperative Soil Survey (NCSS) has been investigating Soil Change within the Interpretations Conference Committees and within the USDA-Natural Resources Conservation Service (NRCS), Soil Science Division since the early 1990’s. Historically, the National Cooperative Soil Survey worked on building a national map that would deliver information on land use and soil management. Soil Mapping, Soil Classification and Soil Taxonomy focused on the static qualities of the soil profile, attempting to make estimates and predictions of soil groupings based on soil characteristics that were stable beyond a 5 to 20 year cycle of use and management and potential anthropogenic change. The National cooperative Soil Survey continues to seek new ways to interpret soils and to make that information more easily accessible. Practice-specific soil interpretations are being explored to support NRCS conservation planning and practice implementation. Other areas of focus include the development of real-time interpretation systems that allow incorporation of site- specific information and interpretation systems that will allow users to incorporate other spatially-referenced data sets including climate and land use to develop accurate and site- specific interpretive information products.

  12. Estimation of soil organic carbon in forests of the United States

    NASA Astrophysics Data System (ADS)

    Domke, G. M.; Perry, C. H.; Walters, B. F.; Woodall, C. W.; Nave, L. E.; Swanston, C.

    2015-12-01

    Soil organic carbon (SOC) is the largest terrestrial carbon (C) sink on earth and management of this pool is a critical component of global efforts to mitigate atmospheric C concentrations. Soil organic carbon is also a key indicator of soil quality as it affects essential biological, chemical, and physical soil functions such as nutrient cycling, water retention, and soil structure maintenance. Much of the SOC on earth is found in forest ecosystems and is thought to be relatively stable. That said, there is growing evidence that SOC may be sensitive to disturbance and global change drivers. In the United States (US), SOC in forests is monitored by the national forest inventory (NFI) conducted by the Forest Inventory and Analysis (FIA) program within the US Department of Agriculture, Forest Service. The FIA program currently uses SOC predictions based on SSURGO/STATSGO data to populate the NFI. Most of estimates of SOC in forests from the SSURGO/STATSGO data are based primarily upon expert opinion and lack systematic field observations. The FIA program has been consistently measuring soil attributes as part of the NFI since 2001 and has amassed an extensive inventory of SOC in forests in the conterminous US and coastal Alaska. Here we present estimates of SOC obtained using data from the NFI and International Soil Carbon Network and describe the modeling framework used to compile estimates for United Nations Framework Convention on Climate Change reporting.

  13. Soil carbon storage following road removal and timber harvesting in redwood forests

    USGS Publications Warehouse

    Seney, Joseph; Madej, Mary Ann

    2015-01-01

    Soil carbon storage plays a key role in the global carbon cycle and is important for sustaining forest productivity. Removal of unpaved forest roads has the potential for increasing carbon storage in soils on forested terrain as treated sites revegetate and soil properties improve on the previously compacted road surfaces. We compared soil organic carbon (SOC) content at several depths on treated roads to SOC in adjacent second-growth forests and old-growth redwood forests in California, determined whether SOC in the upper 50 cm of soil varies with the type of road treatment, and assessed the relative importance of site-scale and landscape-scale variables in predicting SOC accumulation in treated road prisms and second-growth redwood forests. Soils were sampled at 5, 20, and 50 cm depths on roads treated by two methods (decommissioning and full recontouring), and in adjacent second-growth and old-growth forests in north coastal California. Road treatments spanned a period of 32 years, and covered a range of geomorphic and vegetative conditions. SOC decreased with depth at all sites. Treated roads on convex sites exhibited higher SOC than on concave sites, and north aspect sites had higher SOC than south aspect sites. SOC at 5, 20, and 50 cm depths did not differ significantly between decommissioned roads (treated 18–32 years previous) and fully recontoured roads (treated 2–12 years previous). Nevertheless, stepwise multiple regression models project higher SOC developing on fully recontoured roads in the next few decades. The best predictors for SOC on treated roads and in second-growth forest incorporated aspect, vegetation type, soil depth, lithology, distance from the ocean, years since road treatment (for the road model) and years since harvest (for the forest model). The road model explained 48% of the variation in SOC in the upper 50 cm of mineral soils and the forest model, 54%

  14. How does Wildfire Severity Influence Soil Black Carbon in a Minnesota Boreal Forest?

    NASA Astrophysics Data System (ADS)

    Miesel, J. R.; Hockaday, W. C.; Kolka, R. K.

    2014-12-01

    Black carbon (BC) is perceived to be among the most stable forms of carbon (C) and is produced during forest fires via thermal decomposition of organic matter. The factors that contribute to BC formation during fires are poorly understood, although abundant evidence shows that BC may play an important role in nutrient availability when incorporated into soil. How will predicted increases in future wildfire frequency and severity impact the natural formation and ecological function of BC in forest soil? We investigated the effects of fire severity on forest soil in two forest cover types following a major 2011 wildfire event in the Boundary Waters Wilderness Area in northern Minnesota, USA. We sampled the organic horizon and mineral soil (0-10 cm) from stands dominated by jack pine (Pinus banksiana Lamb., hereafter: conifer) and stands dominated by aspen (Populus tremuloides Michx., hereafter: deciduous) within two months after fire. We used cross-polarization and Bloch decay 13C nuclear magnetic resonance spectroscopy and a molecular mixing model to investigate soil organic matter (SOM) composition across a gradient of fire severity in both forest cover types. For both forest types, the BC percent of soil organic carbon (SOC) observed was greatest in moderate-severity areas for the organic horizon, whereas it was greatest in high-severity areas for the mineral soil. Our results to date show that total soil BC stocks increased with fire severity in conifer forest, whereas no clear trend was observed in deciduous forest. Carbohydrate stocks were similar in both forest types and decreased with fire severity. These results suggest that increases in fire severity expected to occur under future climate scenarios may lead to changes in SOM composition and dynamics that in turn influence post-fire forest recovery and C uptake.

  15. Wildfire effects on biological properties of soils in forest-steppe ecosystems of Russia

    NASA Astrophysics Data System (ADS)

    Maksimova, E.; Abakumov, E.

    2014-01-01

    Soils affected by forest wildfires in 2010 in Russia were studied on postfire and mature plots near the Togljatty city, Samara region. Soil biological properties and ash composition dynamics were investigated under the forest fire affect: a place of local forest fire, riding forest fire and unaffected site by fire-control (mature) during 3 yr of restoration. Soil samples were collected at 0-15 cm. Soil biological properties was measured by the fumigation method. The analytical data obtained shows that wildfires lead to serious changes in a soil profile and soil chemistry of upper horizons. Wildfires change a chemical composition of soil horizons and increase their ash-content. Fires lead to accumulation of biogenic elements' content (P and K) in the solum fine earth. Calcium content is increased as a result of fires that leads to an alkaline pH of the solum. The values of nutrients decreased as a result of leaching out with an atmospheric precipitation during the second year of restoration. Thus, when the upper horizons are burning the ash arriving on a soil surface enrich it with nutrients. The mature (unaffected by fire) soils is characterized by the greatest values of soil microbial biomass in the top horizon and, respectively, the bigger values of basal respiration whereas declining of the both parameters was revealed on postfire soils. Nevertheless this influence does not extend on depth more than 10 cm. Thus, fire affect on the soil were recognized in decreasing of microbiological activity.

  16. Final Progress Report on Model-Based Diagnosis of Soil Limitations to Forest Productivity

    SciTech Connect

    Luxmoore, R.J.

    2004-08-30

    This project was undertaken in support of the forest industry to link modeling of nutrients and productivity with field research to identify methods for enhancing soil quality and forest productivity and for alleviating soil limitations to sustainable forest productivity. The project consisted of a series of related tasks, including (1) simulation of changes in biomass and soil carbon with nitrogen fertilization, (2) development of spreadsheet modeling tools for soil nutrient availability and tree nutrient requirements, (3) additional modeling studies, and (4) evaluation of factors involved in the establishment and productivity of southern pine plantations in seasonally wet soils. This report also describes the two Web sites that were developed from the research to assist forest managers with nutrient management of Douglas-fir and loblolly pine plantations.

  17. Human impacts on soil carbon dynamics of deep-rooted Amazonian forests

    NASA Technical Reports Server (NTRS)

    Nepstad, Daniel C.; Stone, Thomas A.; Davidson, Eric A.

    1994-01-01

    Deforestation and logging degrade more forest in eastern and southern Amazonia than in any other region of the world. This forest alteration affects regional hydrology and the global carbon cycle, but our current understanding of these effects is limited by incomplete knowledge of tropical forest ecosystems. It is widely agreed that roots are concentrated near the soil surface in moist tropical forests, but this generalization incorrectly implies that deep roots are unimportant in water and C budgets. Our results indicate that half of the closed-canopy forests of Brazilian Amazonic occur where rainfall is highly seasonal, and these forests rely on deeply penetrating roots to extract soil water. Pasture vegetation extracts less water from deep soil than the forest it replaces, thus increasing rates of drainage and decreasing rates of evapotranspiration. Deep roots are also a source of modern carbon deep in the soil. The soils of the eastern Amazon contain more carbon below 1 m depth than is present in above-ground biomass. As much as 25 percent of this deep soil C could have annual to decadal turnover times and may be lost to the atmosphere following deforestation. We compared the importance of deep roots in a mature, evergreen forest with an adjacent man-made pasture, the most common type of vegetation on deforested land in Amazonia. The study site is near the town of Paragominas, in the Brazilian state of Para, with a seasonal rainfall pattern and deeply-weathered, kaolinitic soils that are typical for large portions of Amazonia. Root distribution, soil water extraction, and soil carbon dynamics were studied using deep auger holes and shafts in each ecosystem, and the phenology and water status of the leaf canopies were measured. We estimated the geographical distribution of deeply-rooting forests using satellite imagery, rainfall data, and field measurements.

  18. Soil Carbon Storage and Turnover in an Old-Growth Coastal Redwood Forest and Adjacent Prairie

    NASA Astrophysics Data System (ADS)

    McFarlane, K. J.; Torn, M. S.; Mambelli, S.; Dawson, T. E.

    2010-12-01

    Coastal redwood (Sequoia sempervirens) forests store lots of carbon in aboveground tree biomass because redwoods are very long-lived and can grow very large. Redwood is known for its high resistance to decay, a result of high levels of aromatic compounds (tannins) in the tree’s tissues. We tested the hypothesis that because coastal redwoods are highly productive and produce organic matter that is chemically resistant to decay, old-growth redwood forests should store large amounts of stabilized soil carbon. We measured soil C storage to 110 cm depth in an old-growth coastal redwood forest and used physical soil fractionation combined with radiocarbon measurements to determine soil organic matter turnover time. In addition, we measured soil C storage and turnover at an adjacent prairie experiencing the same climate and with soils derived from the same parent material. We found larger soil C stocks to 110 cm at the prairie (350 Mg C ha-1) than the redwood forest (277 Mg C ha-1) even with O-horizons included for the forest. Larger N stocks were also observed at the prairie than the redwood and these differences in stocks were driven by higher C and N concentrations in mineral soils at the prairie. Differences between ecosystems in soil C and N concentrations, C:N ratios, and C and N stocks were observed for the top 50 cm only, suggesting that the influence of the different litter types did not extend to deeper soils. Contrary to what was expected, bulk soil and heavy density-fraction Δ14C values were higher, indicating shorter turnover times, for the redwood forest than the prairie. In summary, we did not observe greater C storage or 14C-based turnover times in old-growth redwood forest compared to adjacent prairie, suggesting chemical recalcitrance of litter inputs does not drive soil C stabilization at these ecosystems.

  19. [Effects of different forest restoration approaches on the soil quality in red soil region of Southern China].

    PubMed

    Wang, Yun; Ouyang, Zhi-Yun; Zheng, Hua; Zeng, Jing; Chen, Fa-Lin; Zhang, Kai

    2013-05-01

    In 2008-2009, an investigation was conducted on the effects of three typical forest restoration approaches, i. e., naturally restored secondary forest, artificially restored native species Pinus massoniana plantation (Masson pine plantation), and introduced species Pinus elliottii plantation (slash pine plantation), on the soil quality in red soil region of Southern China. The results showed that the soil moisture content, bulk density, particle composition, and the contents of total carbon (C), total nitrogen (N), total phosphorus (P), organic C, available N, available P, and available potassium (K) in natural secondary forest were all superior to those in artificial plantations. The soil physical, chemical, and microbial properties were integrated into a soil quality index, which was significantly higher (1.20 +/- 0.10) in natural secondary forest than in Masson pine plantation (0.59 +/- 0.03) and slash pine plantation (0.59 +/- 0.06). Our results suggested as compared with the restoration with native species P. massoniana and with introduced P. elliottii, natural restoration could be a better forest restoration approach to improve the soil quality in red soil region of Southern China. PMID:24015552

  20. Forest cockchafer larvae as methane production hotspots in soils and their importance for net soil methane fluxes

    NASA Astrophysics Data System (ADS)

    Görres, Carolyn-Monika; Kammann, Claudia; Murphy, Paul; Müller, Christoph

    2016-04-01

    Certain groups of soil invertebrates, namely scarab beetles and millipedes, are capable of emitting considerable amounts of methane due to methanogens inhabiting their gut system. It was already pointed out in the early 1990's, that these groups of invertebrates may represent a globally important source of methane. However, apart from termites, the importance of invertebrates for the soil methane budget is still unknown. Here, we present preliminary results of a laboratory soil incubation experiment elucidating the influence of forest cockchafer larvae (Melolontha hippocastani FABRICIUS) on soil methane cycling. In January/February 2016, two soils from two different management systems - one from a pine forest (extensive use) and one from a vegetable field (intensive use) - were incubated for 56 days either with or without beetle larvae. Net soil methane fluxes and larvae methane emissions together with their stable carbon isotope signatures were quantified at regular intervals to estimate gross methane production and gross methane oxidation in the soils. The results of this experiment will contribute to testing the hypothesis of whether methane production hotspots can significantly enhance the methane oxidation capacity of soils. Forest cockchafer larvae are only found in well-aerated sandy soils where one would usually not suspect relevant gross methane production. Thus, besides quantifying their contribution to net soil methane fluxes, they are also ideal organisms to study the effect of methane production hotspots on overall soil methane cycling. Funding support: Reintegration grant of the German Academic Exchange Service (DAAD) (#57185798).

  1. Drivers of methane uptake by montane forest soils in the Peruvian Andes

    NASA Astrophysics Data System (ADS)

    Jones, Sam; Diem, Torsten; Huaraca Quispe, Lidia; Cahuana, Adan; Meir, Patrick; Teh, Yit

    2016-04-01

    The exchange of methane between the soils of humid tropical forests and the atmosphere is relatively poorly documented. This is particularly true of montane settings where variations between uptake and emission of atmospheric methane have been observed. Whilst most of these ecosystems appear to function as net sinks for atmospheric methane, some act as considerable sources. In regions like the Andes, humid montane forests are extensive and a better understanding of the magnitude and controls on soil-atmosphere methane exchange is required. We report methane fluxes from upper montane cloud forest (2811 - 2962 m asl), lower montane cloud forest (1532 - 1786 m asl), and premontane forest (1070 - 1088 m asl) soils in south-eastern Peru. Between 1000 and 3000 m asl, mean annual air temperature and total annual precipitation decrease from 24 ° C and 5000 mm to 12 ° C and 1700 mm. The study region experiences a pronounced wet season between October and April. Monthly measurements of soil-atmosphere gas exchange, soil moisture, soil temperature, soil oxygen concentration, available ammonium and available nitrate were made from February 2011 in the upper and lower montane cloud forests and July 2011 in the premontane forest to June 2013. These soils acted as sinks for atmospheric methane with mean net fluxes for wet and dry season, respectively, of -2.1 (0.2) and -1.5 (0.1) mg CH4 m‑2 d‑1 in the upper montane forest; -1.5 (0.2) and -1.4 (0.1) mg CH4 m‑2 d‑1in the lower montane forest; and -0.3 (0.2) and -0.2 (0.2) mg CH4 m‑2 d‑1 in the premontane forest. Spatial variations among forest types were related to available nitrate and water-filled pore space suggesting that nitrate inhibition of oxidation or constraints on the diffusional supply of methane to methanotrophic communities may be important controls on methane cycling in these soils. Seasonality in methane exchange, with weaker uptake related to increased water-filled pore space and soil temperature

  2. Alternate data sources for soil surveys on rangeland

    USGS Publications Warehouse

    Horvath, Emil H.; Klingebiel, A.A.; Moore, D.G.; Fosnight, E.A.

    1983-01-01

    the feasibility of using this approach for producing physiographic maps as an aid for mapping soils and range sites. The project is a cooperative investigation of the Earth Resources Observation Systems Data Center of the U.S. Geological Survey, the Soil Conservation Service, and the Bureau of Land Management.

  3. Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

    PubMed Central

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  4. Soil microbial biomass, basal respiration and enzyme activity of main forest types in the Qinling Mountains.

    PubMed

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  5. Forest gaps slow the sequestration of soil organic matter: a humification experiment with six foliar litters in an alpine forest

    PubMed Central

    Ni, Xiangyin; Yang, Wanqin; Tan, Bo; Li, Han; He, Jie; Xu, Liya; Wu, Fuzhong

    2016-01-01

    Humification of plant litter containing carbon and other nutrients greatly contributes to the buildup of soil organic matter, but this process can be altered by forest gap-induced environmental variations during the winter and growing seasons. We conducted a field litterbag experiment in an alpine forest on the eastern Tibetan Plateau from November 2012 to October 2014. Six dominant types of foliar litter were placed on the forest floor in various forest gap positions, including gap centre, canopy gap, expanded gap and closed canopy. Over two years of incubation, all foliar litters were substantially humified especially during the first winter, although the newly accumulated humic substances were young and could be decomposed further. The forest gaps exhibited significant effects on early litter humification, but the effects were regulated by sampling seasons and litter types. Compared with the litter under the closed canopy, humification was suppressed in the gap centre after two years of field incubation. The results presented here suggest that gap formation delays the accumulation of soil organic matter, and reduces soil carbon sequestration in these alpine forests. PMID:26790393

  6. Forest gaps slow the sequestration of soil organic matter: a humification experiment with six foliar litters in an alpine forest.

    PubMed

    Ni, Xiangyin; Yang, Wanqin; Tan, Bo; Li, Han; He, Jie; Xu, Liya; Wu, Fuzhong

    2016-01-01

    Humification of plant litter containing carbon and other nutrients greatly contributes to the buildup of soil organic matter, but this process can be altered by forest gap-induced environmental variations during the winter and growing seasons. We conducted a field litterbag experiment in an alpine forest on the eastern Tibetan Plateau from November 2012 to October 2014. Six dominant types of foliar litter were placed on the forest floor in various forest gap positions, including gap centre, canopy gap, expanded gap and closed canopy. Over two years of incubation, all foliar litters were substantially humified especially during the first winter, although the newly accumulated humic substances were young and could be decomposed further. The forest gaps exhibited significant effects on early litter humification, but the effects were regulated by sampling seasons and litter types. Compared with the litter under the closed canopy, humification was suppressed in the gap centre after two years of field incubation. The results presented here suggest that gap formation delays the accumulation of soil organic matter, and reduces soil carbon sequestration in these alpine forests. PMID:26790393

  7. Uncertainties in forest soil carbon and nitrogen estimates related to soil sampling methods in the Delaware River Basin

    NASA Astrophysics Data System (ADS)

    Xu, B.; Plante, A. F.; Johnson, A. H.; Pan, Y.

    2014-12-01

    Estimating forest soil carbon and nitrogen (CN) is critical to understanding ecosystem responses to changing climate, disturbance and forest management practices. Most of the uncertainty in soil CN cycling is associated with the difficulty in characterizing soil properties in field sampling because forest soils can be rocky, inaccessible and spatially heterogeneous. A composite coring technique is broadly applied as the standard FIA soil sampling protocol. However, the accuracy of this method might be limited by soil compaction, rock obstruction and plot selection problems during sampling. In contrast, the quantitative soil pit sampling method may avoid these problems and provides direct measurements of soil mass, rock volume and CN concentration representative of a larger ground surface area. In this study, the two sampling methods were applied in 60 forest plots, randomly located in three research areas in the Delaware River Basin in the U.S. Mid-Atlantic region. In each of the plots, one quantitative soil pit was excavated and three soil cores were collected. Our results show that average soil bulk density in the top 20 cm mineral soil measured from the soil cores was consistently lower than bulk density measured by soil pits. However, the volume percentage of coarse fragments measured by the core method was also significantly lower than the pit method. Conversely, CN concentrations were greater in core samples compared to pit samples. The resulting soil carbon content (0-20 cm) was estimated to be 4.1 ± 0.4 kg m-2 in the core method compared to 4.5 ± 0.4 kg m-2 in the pit method. Lower bulk density but higher CN concentration and lower coarse fragments content from the cores have offset each other, resulting in no significant differences in CN content from the soil pit method. Deeper soil (20-40 cm), which is not accessible in the core method, accounted for 29% of the total soil carbon stock (0-40 cm) in the pit method. Our results suggest that, although soil

  8. Effects of harvest management practices on forest biomass and soil carbon in eucalypt forests in New South Wales, Australia: Simulations with the forest succession model LINKAGES

    SciTech Connect

    Ranatunga, Kemachandra; Keenan, Rodney J.; Wullschleger, Stan D; Post, Wilfred M; Tharp, M Lynn

    2008-01-01

    Understanding long-term changes in forest ecosystem carbon stocks under forest management practices such as timber harvesting is important for assessing the contribution of forests to the global carbon cycle. Harvesting effects are complicated by the amount, type, and condition of residue left on-site, the decomposition rate of this residue, the incorporation of residue into soil organic matter and the rate of new detritus input to the forest floor from regrowing vegetation. In an attempt to address these complexities, the forest succession model LINKAGES was used to assess the production of aboveground biomass, detritus, and soil carbon stocks in native Eucalyptus forests as influenced by five harvest management practices in New South Wales, Australia. The original decomposition sub-routines of LINKAGES were modified by adding components of the Rothamsted (RothC) soil organic matter turnover model. Simulation results using the new model were compared to data from long-term forest inventory plots. Good agreement was observed between simulated and measured above-ground biomass, but mixed results were obtained for basal area. Harvesting operations examined included removing trees for quota sawlogs (QSL, DBH >80 cm), integrated sawlogs (ISL, DBH >20 cm) and whole-tree harvesting in integrated sawlogs (WTH). We also examined the impact of different cutting cycles (20, 50 or 80 years) and intensities (removing 20, 50 or 80 m{sup 3}). Generally medium and high intensities of shorter cutting cycles in sawlog harvesting systems produced considerably higher soil carbon values compared to no harvesting. On average, soil carbon was 2-9% lower in whole-tree harvest simulations whereas in sawlog harvest simulations soil carbon was 5-17% higher than in no harvesting.

  9. Significant and persistent impact of timber harvesting on soil microbial communities in Northern coniferous forests.

    PubMed

    Hartmann, Martin; Howes, Charles G; VanInsberghe, David; Yu, Hang; Bachar, Dipankar; Christen, Richard; Henrik Nilsson, Rolf; Hallam, Steven J; Mohn, William W

    2012-12-01

    Forest ecosystems have integral roles in climate stability, biodiversity and economic development. Soil stewardship is essential for sustainable forest management. Organic matter (OM) removal and soil compaction are key disturbances associated with forest harvesting, but their impacts on forest ecosystems are not well understood. Because microbiological processes regulate soil ecology and biogeochemistry, microbial community structure might serve as indicator of forest ecosystem status, revealing changes in nutrient and energy flow patterns before they have irreversible effects on long-term soil productivity. We applied massively parallel pyrosequencing of over 4.6 million ribosomal marker sequences to assess the impact of OM removal and soil compaction on bacterial and fungal communities in a field experiment replicated at six forest sites in British Columbia, Canada. More than a decade after harvesting, diversity and structure of soil bacterial and fungal communities remained significantly altered by harvesting disturbances, with individual taxonomic groups responding differentially to varied levels of the disturbances. Plant symbionts, like ectomycorrhizal fungi, and saprobic taxa, such as ascomycetes and actinomycetes, were among the most sensitive to harvesting disturbances. Given their significant ecological roles in forest development, the fate of these taxa might be critical for sustainability of forest ecosystems. Although abundant bacterial populations were ubiquitous, abundant fungal populations often revealed a patchy distribution, consistent with their higher sensitivity to the examined soil disturbances. These results establish a comprehensive inventory of bacterial and fungal community composition in northern coniferous forests and demonstrate the long-term response of their structure to key disturbances associated with forest harvesting. PMID:22855212

  10. Significant and persistent impact of timber harvesting on soil microbial communities in Northern coniferous forests

    PubMed Central

    Hartmann, Martin; Howes, Charles G; VanInsberghe, David; Yu, Hang; Bachar, Dipankar; Christen, Richard; Henrik Nilsson, Rolf; Hallam, Steven J; Mohn, William W

    2012-01-01

    Forest ecosystems have integral roles in climate stability, biodiversity and economic development. Soil stewardship is essential for sustainable forest management. Organic matter (OM) removal and soil compaction are key disturbances associated with forest harvesting, but their impacts on forest ecosystems are not well understood. Because microbiological processes regulate soil ecology and biogeochemistry, microbial community structure might serve as indicator of forest ecosystem status, revealing changes in nutrient and energy flow patterns before they have irreversible effects on long-term soil productivity. We applied massively parallel pyrosequencing of over 4.6 million ribosomal marker sequences to assess the impact of OM removal and soil compaction on bacterial and fungal communities in a field experiment replicated at six forest sites in British Columbia, Canada. More than a decade after harvesting, diversity and structure of soil bacterial and fungal communities remained significantly altered by harvesting disturbances, with individual taxonomic groups responding differentially to varied levels of the disturbances. Plant symbionts, like ectomycorrhizal fungi, and saprobic taxa, such as ascomycetes and actinomycetes, were among the most sensitive to harvesting disturbances. Given their significant ecological roles in forest development, the fate of these taxa might be critical for sustainability of forest ecosystems. Although abundant bacterial populations were ubiquitous, abundant fungal populations often revealed a patchy distribution, consistent with their higher sensitivity to the examined soil disturbances. These results establish a comprehensive inventory of bacterial and fungal community composition in northern coniferous forests and demonstrate the long-term response of their structure to key disturbances associated with forest harvesting. PMID:22855212

  11. Predicting local Soil- and Land-units with Random Forest in the Senegalese Sahel

    NASA Astrophysics Data System (ADS)

    Grau, Tobias; Brandt, Martin; Samimi, Cyrus

    2013-04-01

    MODIS (MCD12Q1) or Globcover are often the only available global land-cover products, however ground-truthing in the Sahel of Senegal has shown that most classes do have any agreement with actual land-cover making those products unusable in any local application. We suggest a methodology, which models local Wolof land- and soil-types in an area in the Senegalese Ferlo around Linguère at different scales. In a first step, interviews with the local population were conducted to ascertain the local denotation of soil units, as well as their agricultural use and woody vegetation mainly growing on them. "Ndjor" are soft sand soils with mainly Combretum glutinosum trees. They are suitable for groundnuts and beans while millet is grown on hard sand soils ("Bardjen") dominated by Balanites aegyptiaca and Acacia tortilis. "Xur" are clayey depressions with a high diversity of tree species. Lateritic pasture sites with dense woody vegetation (mostly Pterocarpus lucens and Guiera senegalensis) have never been used for cropping and are called "All". In a second step, vegetation and soil parameters of 85 plots (~1 ha) were surveyed in the field. 28 different soil parameters are clustered into 4 classes using the WARD algorithm. Here, 81% agree with the local classification. Then, an ordination (NMDS) with 2 dimensions and a stress-value of 9.13% was calculated using the 28 soil parameters. It shows several significant relationships between the soil classes and the fitted environmental parameters which are derived from field data, a digital elevation model, Landsat and RapidEye imagery as well as TRMM rainfall data. Landsat's band 5 reflectance values (1.55 - 1.75 µm) of mean dry season image (2000-2010) has a R² of 0.42 and is the most important of 9 significant variables (5%-level). A random forest classifier is then used to extrapolate the 4 classes to the whole study area based on the 9 significant environmental parameters. At a resolution of 30 m the OBB (out-of-bag) error

  12. Strong indications of nitrogen limited methane uptake in tropical forest soils

    NASA Astrophysics Data System (ADS)

    Veldkamp, E.; Koehler, B.; Corre, M. D.

    2012-04-01

    Tropical forest soils contribute an estimated 6.2 Tg yr-1 (27%) to global methane (CH4) uptake, which is large enough to alter the CH4 accumulation in the atmosphere if significant changes would occur to this sink. Elevated deposition of inorganic nitrogen (N) to temperate forest ecosystems has shown to reduce CH4 fluxes from forest soils, but almost no information exists from tropical forest soils even though projections show that N deposition will increase substantially in tropical regions. Here we report the results of a long-term, ecosystem scale experiment in which we assess the impact of chronic N addition on soil CH4 fluxes from two old-growth tropical forests in Panama: a lowland forest on a deeply weathered soil with control and 9-12-yr N addition, and a montane forest on a less-developed volcanic soil with control and 1-4-yr N addition. CH4 fluxes from the lowland forest control plots (-21.47 ± 1.57 μg CH4-C m-2 h-1) and the montane forest control plots (-3.99 ± 3.40 μg CH4-C m-2 h-1) did not significantly differ from their respective N-addition plots. In the lowland forest, chronic N addition did not lead to inhibition of CH4 uptake; in contrast, a negative correlation of NO3- with CH4 fluxes in these plots suggests that higher NO3- availability may have stimulated CH4 consumption and/or reduced CH4 production. Also in the montane forest, we detected negative correlation of CH4 fluxes with NH4+ both in the organic layer and mineral soil, which we interpret as evidence that CH4 consumption may have been N limited. That chronic N addition did not lead to higher CH4 uptake at any of these sites was probably caused by the large spatial variability of CH4 fluxes which may have rendered treatment effect not statistically significant. Furthermore, in the lowland forest soil CH4 uptake was limited by diffusion of CH4 from the atmosphere into the soil, which was not alleviated by N addition. We conclude that in these extremely different tropical forest

  13. Fine root dynamics for forests on contrasting soils in the colombian Amazon

    NASA Astrophysics Data System (ADS)

    Jiménez, E. M.; Moreno, F. H.; Lloyd, J.; Peñuela, M. C.; Patiño, S.

    2009-03-01

    It has been hypothesized that in a gradient of increase of soil resources carbon allocated to belowground production (fine roots) decreases. To evaluate this hypothesis, we measured the mass and production of fine roots (<2 mm) by two methods: 1) ingrowth cores and, 2) sequential soil coring, during 2.2 years in two lowland forests with different soils in the colombian Amazon. Differences of soil resources were determined by the type and physical and chemical properties of soil: a forest on loamy soil (Ultisol) at the Amacayacu National Natural Park and, the other on white sands (Spodosol) at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that mass and production of fine roots was significantly different between soil depths (0-10 and 10-20 cm) and also between forests. White-sand forest allocated more carbon to fine roots than the clayey forest; the production in white-sand forest was twice (2.98 and 3.33 Mg C ha-1 year-1, method 1 and 2, respectively) as much as in clayey forest (1.51 and 1.36-1.03 Mg C ha-1 year-1, method 1 and 2, respectively); similarly, the average of fine root mass was higher in the white-sand forest (10.94 Mg C ha-1) than in the forest on clay soils (3.04-3.64 Mg C ha-1). The mass of fine roots also showed a temporal variation related to rainfall, such that production of fine roots decreased substantially in the dry period of the year 2005. Our results suggest that soil resources play an important role in patterns of carbon allocation in these forests; carbon allocated to above-and belowground organs is different between forest types, in such a way that a trade-off above/belowground seems to exist; as a result, it is probable that there are not differences in total net primary productivity between these two forests: does belowground offset lower aboveground production in poorer soils?

  14. Use of mathematical models for assessing the pool and dynamics of carbon in forest soils

    NASA Astrophysics Data System (ADS)

    Komarov, A. S.

    2008-12-01

    The contribution of forest soils to the total carbon budget and to the emission of greenhouse gases is an important problem involved in many international programs, including the Kyoto Protocol. Direct measurements of the carbon pool in forest soils and its changes are slow and expensive; therefore, mathematical models are proposed in different countries for describing the dynamics of soil organic matter (SOM). The models differ in complexity and consider different processes of SOM mineralization and humification. The input parameters include model coefficients (these are usually the rates of decomposition and humification of different SOM compartments) and the initial values for different SOM pools. The coefficients can be estimated in special laboratory and field experiments, but the characteristics of the initial values for different SOM pools are usually absent. In this case, some assumptions about the character of SOM accumulation, which depends on forest vegetation, are used. The most realistic is the use of databases on the pools of carbon and other elements related to the types of forest or habitat conditions, including the primarily water regime and soil fertility. Under some suppositions, the agreement conditions between the main parameters of the SOM and forest vegetation can be formulated to assess the initial SOM pools in the forest litter and mineral horizons of the soil. An example of assessing the prediction of forest soil dynamics in Leningrad oblast was considered.

  15. Soil Changes Induced by Rubber and Tea Plantation Establishment: Comparison with Tropical Rain Forest Soil in Xishuangbanna, SW China

    NASA Astrophysics Data System (ADS)

    Li, Hongmei; Ma, Youxin; Liu, Wenjie; Liu, Wenjun

    2012-11-01

    Over the past thirty years, Xishuangbanna in Southwestern China has seen dramatic changes in land use where large areas of tropical forest and fallow land have been converted to rubber and tea plantations. In this study we evaluated the effects of land use and slope on soil properties in seven common disturbed and undisturbed land-types. Results indicated that all soils were acidic, with pH values significantly higher in the 3- and 28-year-old rubber plantations. The tropical forests had the lowest bulk densities, especially significantly lower from the top 10 cm of soil, and highest soil organic matter concentrations. Soil moisture content at topsoil was highest in the mature rubber plantation. Soils in the tropical forests and abandoned cultivated land had inorganic N (IN) concentrations approximately equal in NH4 +-N and NO3 --N. However, soil IN pools were dominated by NH4 +-N in the rubber and tea plantations. This trend suggests that conversion of tropical forest to rubber and tea plantations increases NH4 +-N concentration and decreases NO3 --N concentration, with the most pronounced effect in plantations that are more frequently fertilized. Soil moisture content, IN, NH4 +-N and NO3 --N concentrations within all sites were higher in the rainy season than in the dry season. Significant differences in the soil moisture content, and IN, NH4 +-N and NO3 --N concentration was detected for both land uses and sampling season effects, as well as interactions. Higher concentrations of NH4 +-N were measured at the upper slopes of all sites, but NO3 --N concentrations were highest at the lower slope in the rubber plantations and lowest at the lower slopes at all other. Thus, the conversion of tropical forests to rubber and tea plantations can have a profound effect on soil NH4 +-N and NO3 --N concentrations. Options for improved soil management in plantations are discussed.

  16. Effect of soil carbohydrates on nutrient availability in natural forests and cultivated lands in Sri Lanka

    NASA Astrophysics Data System (ADS)

    Ratnayake, R. R.; Seneviratne, G.; Kulasooriya, S. A.

    2013-05-01

    Carbohydrates supply carbon sources for microbial activities that contribute to mineral nutrient production in soil. Their role on soil nutrient availability has not yet been properly elucidated. This was studied in forests and cultivated lands in Sri Lanka. Soil organic matter (SOM) fractions affecting carbohydrate availability were also determined. Soil litter contributed to sugars of plant origin (SPO) in croplands. The negative relationship found between clay bound organic matter (CBO) and glucose indicates higher SOM fixation in clay that lower its availability in cultivated lands. In forests, negative relationships between litter and sugars of microbial origin (SMO) showed that litter fuelled microbes to produce sugars. Fucose and glucose increased the availability of Cu, Zn and Mn in forests. Xylose increased Ca availability in cultivated lands. Arabinose, the main carbon source of soil respiration reduced the P availability. This study showed soil carbohydrates and their relationships with mineral nutrients could provide vital information on the availability of limiting nutrients in tropical ecosystems.

  17. Forest thinning and soil respiration in a ponderosa pine plantation in the Sierra Nevada.

    PubMed

    Tang, Jianwu; Qi, Ye; Xu, Ming; Misson, Laurent; Goldstein, Allen H

    2005-01-01

    Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and chemical properties. Forest thinning changes soil temperature, soil water content, and root density and activity, and thus changes soil respiration. We measured soil respiration monthly and soil temperature and volumetric soil water continuously in a young ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) plantation in the Sierra Nevada Mountains in California from June 1998 to May 2000 (before a thinning that removed 30% of the biomass), and from May to December 2001 (after thinning). Thinning increased the spatial homogeneity of soil temperature and respiration. We conducted a multivariate analysis with two independent variables of soil temperature and water and a categorical variable representing the thinning event to simulate soil respiration and assess the effect of thinning. Thinning did not change the sensitivity of soil respiration to temperature or to water, but decreased total soil respiration by 13% at a given temperature and water content. This decrease in soil respiration was likely associated with the decrease in root density after thinning. With a model driven by continuous soil temperature and water time series, we estimated that total soil respiration was 948, 949 and 831 g C m(-2) year(-1) in the years 1999, 2000 and 2001, respectively. Although thinning reduced soil respiration at a given temperature and water content, because of natural climate variability and the thinning effect on soil temperature and water, actual cumulative soil respiration showed no clear trend following thinning. We conclude that the effect of forest thinning on soil respiration is the combined result of a decrease in root respiration, an increase in soil organic matter, and changes in soil temperature and water due to both thinning and interannual climate variability. PMID:15519986

  18. Fungal Taxa Target Different Carbon Substrates in Harvard Forest Soils

    NASA Astrophysics Data System (ADS)

    Hanson, C. A.; Allison, S. D.; Wallenstein, M. D.; Mellilo, J. M.; Treseder, K. K.

    2006-12-01

    The mineralization of soil organic carbon is a major component of the global carbon cycle and is largely controlled by soil microbial communities. However, little is known about the functional roles of soil microbes or whether different microbial taxa target different carbon substrates under natural conditions. To examine this possibility, we assessed the community composition of active fungi by using a novel nucleotide analog technique in soils from the Harvard Forest. We hypothesized that fungal community composition would shift in response to the addition of different substrates and that specific fungal taxa would respond differentially to particular carbon sources. To test this hypothesis, we added a nucleotide analog probe directly to soils in conjunction with one of five carbon compounds of increasing recalcitrance: glycine, sucrose, cellulose, tannin-protein complex, and lignin. During 48 hour incubations, the nucleotide analog was incorporated into newly replicated DNA of soil organisms that proliferated following the addition of the substrates. In this way, we labeled the DNA of microbes that respond to a particular carbon source. Labeled DNA was isolated and fungal Internal Transcribed Spacer (ITS) regions of ribosomal DNA (rDNA) were sequenced and analyzed to identify active fungi to near-species resolution. Diversity analyses at the ≥97% sequence similarity level indicated that taxonomic richness was greater under cellulose (Shannon Index: 3.23 ± 0.11 with ± 95% CI) and lignin (2.87 ± 0.15) additions than the other treatments (2.34 ± 0.16 to 2.64 ± 0.13). In addition, community composition of active fungi shifted under glycine, sucrose, and cellulose additions. Specifically, the community under glycine was significantly different from communities under control, cellulose, and tannin-protein (P<0.05). Additionally, the sucrose and cellulose communities were marginally different from the control community (P = 0.059 and 0.054, respectively) and

  19. Immediate and long-term fire effects on total mercury in forests soils of northeastern Minnesota.

    PubMed

    Woodruff, Laurel G; Cannon, William F

    2010-07-15

    Within the Boundary Waters Canoe Area Wilderness in northeastern Minnesota, soils were collected from 116 sites in areas of primarily virgin forest with fire-origin stand years (year of last recognizable stand-killing wildfire) that range from the 1759 to 1976. Median concentrations for total mercury in soils for this span of 217 years range from 0.28 +/- 0.088 ppm (1759) to 0.09 +/- 0.047 ppm (1976) for A-horizon soils and from 0.23 +/- 0.062 ppm (1759) to 0.09 +/- 0.018 ppm (1976) for O-horizon soils. A separate study of soils collected from 30 sites within an area that burned in a 2004 wildfire at Voyageurs National Park, northern Minnesota, suggested that high soil burn severity resulted in significant mercury loss from both organic and mineral soils. Integrated data from these two studies and additional regional soil data demonstrate that older forests have progressively higher mercury concentrations in O-horizon soils (r(2) = 0.423) and A-horizon soils (r(2) = 0.456). These results support the hypotheses that an important factor for mercury concentrations in forest soils is time since stand-replacing fire and that high soil burn severity has the potential to reduce the concentration of mercury in burned soils for tens to hundreds of years. PMID:20553021

  20. Mineral Soil Carbon in Managed Hardwood Forests of the Northeastern US

    NASA Astrophysics Data System (ADS)

    Vario, C.; Friedland, A.; Hornig, C.

    2013-12-01

    New England is characterized by extensive forest cover and large reservoirs of soil carbon (C). In northern hardwood forests, mineral soil C can account for up to 50% of total ecosystem C. There has been an increasing demand for forests to serve both as a C sink and a renewable energy source, and effective management of the ecosystem C balance relies on accurate modeling of each compartment of the ecosystem. However, the dynamics of soil C storage with respect to forest use are variable and poorly understood, particularly in mineral soils. For example, current regional models assume C pools after forest harvesting do not change, while some studies suggest that belowground mineral soil C pools can be affected by disturbances at the soil surface. We quantified mineral soil C pools in previously clear-cut stands in seven research or protected forests across New York, New Hampshire, Massachusetts, and Vermont. The ages of the sites sampled ranged from recently cleared to those with no disturbance history, with 21 forest stands represented in the study. Within each research forest studied, physical parameters such as soil type, forest type, slope and land-use history (aside from forest harvest) did not vary between the stands of different ages. Soil samples were collected to a depth of 60 cm below the mineral-organic boundary using a gas-powered augur and 9.5-cm diameter drill bit. Samples were collected in 10-cm increments in shallow mineral soil and 15-cm increments from 30-60 cm depth. Carbon, nitrogen (N), pH, texture and soil mineralogy were measured across the regional sites. At Bartlett Experimental Forest (BEF) in New Hampshire, mineral soil biogeochemistry in cut and uncut sites was studied at a finer scale. Measurements included soil temperature to 55 cm depth, carbon compound analyses using Py-GCMS and soil microbial messenger RNA extractions from mineral soil. Finally, we simulated C dynamics after harvesting by building a model in Stella, with a particular

  1. Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

    USGS Publications Warehouse

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

  2. Complementary models of tree species-soil relationships in old-growth temperate forests

    USGS Publications Warehouse

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

  3. Landscape heterogeneity, soil climate, and carbon exchange in a boreal black spruce forest.

    PubMed

    Dunn, Allison L; Wofsy, Steven C; v H Bright, Alfram

    2009-03-01

    We measured soil climate and the turbulent fluxes of CO2, H2O, heat, and momentum on short towers (2 m) in a 160-yr-old boreal black spruce forest in Manitoba, Canada. Two distinct land cover types were studied: a Sphagnum-dominated wetland, and a feathermoss (Pleurozium and Hylocomium)-dominated upland, both lying within the footprint of a 30-m tower, which has measured whole-forest carbon exchange since 1994. Peak summertime uptake of CO2, was higher in the wetland than for the forest as a whole due to the influence of deciduous shrubs. Soil respiration rates in the wetland were approximately three times larger than in upland soils, and 30% greater than the mean of the whole forest, reflecting decomposition of soil organic matter. Soil respiration rates in the wetland were regulated by soil temperature, which was in turn influenced by water table depth through effects on soil heat capacity and conductivity. Warmer soil temperatures and deeper water tables favored increased heterotrophic respiration. Wetland drainage was limited by frost during the first half of the growing season, leading to high, perched water tables, cool soil temperatures, and much lower respiration rates than observed later in the growing season. Whole-forest evapotranspiration increased as water tables dropped, suggesting that photosynthesis in this forest was rarely subject to water stress. Our data indicate positive feedback between soil temperature, seasonal thawing, heterotrophic respiration, and evapotranspiration. As a result, climate warming could cause covariant changes in soil temperature and water table depths that may stimulate photosynthesis and strongly promote efflux of CO2 from peat soils in boreal wetlands. PMID:19323205

  4. Modeling Storm Water Runoff and Soil Interflow in a Managed Forest, Upper Coastal Plain of the Southeast US.

    SciTech Connect

    Callahan, T.J.; Cook, J.D.; Coleman, Mark D.; Amatya, Devendra M.; Trettin, Carl C.

    2004-08-01

    The Forest Service-Savannah River is conducting a hectare-scale monitoring and modeling study on forest productivity in a Short Rotation Woody Crop plantation at the Savannah River Site, which is on Upper Coastal Plain of South Carolina. Detailed surveys, i.e., topography, soils, vegetation, and dainage network, of small (2-5 ha) plots have been completed in a 2 square-km watershed draining to Fourmile Creek, a tributary of the Savannah River. We wish to experimentally determine the relative importance of interflow on water yield and water quality at this site. Interflow (shallow subsurface lateral flow) can short-circuit rainfall infiltration, preventing deep seepage and resulting in water and chemical residence times in the watershed much shorter than that if deep seepage were the sole component of infiltration. The soil series at the site (Wagram, Dothan, Fuquay, Ogeechee, and Vaucluse) each have a clay-rich B horizon of decimeter-scale thickness at depths of 1-2 m below surface. As interflow is affected by rainfall intensity and duration and soil properties such as porosity, permeability, and antecedent soil moisture, our calculations made using the Green and Ampt equation show that the intensity and duration of a storm event must be greater than about 3 cm per hour and 2 hours, respectively, in order to initiate interflow for the least permeable soils series (Vaucluse). Tabulated values of soil properties were used in these preliminary calculations. Simulations of the largest rainfall events from 1972-2002 data using the Green and Ampt equation provide an interflow: rainfall ratio of 0 for the permeable Wagram soil series (no interflow) compared to 0.46 for the less permeable Vaucluse soil series. These initial predictions will be compared to storm water hydrographs of interflow collected at the outflow point of each plot and refined using more detailed soil property measurements.

  5. Revealing plot scale heterogeneity in soil moisture dynamics under contrasting vegetation assemblages using 3D electrical resistivity tomography (ERT) surveys

    NASA Astrophysics Data System (ADS)

    Dick, Jonathan; Tetzlaff, Doerthe; Bradford, John; Soulsby, Chris

    2016-04-01

    Soil moisture is a fundamental component of the water cycle that influences many hydrological processes, such as flooding, solute transport, biogeochemical processes, and land-atmosphere interactions. The relationship between vegetation and soil moisture is complex and reciprocal. Soil moisture may affect vegetation distribution due to its function as the primary source of water, in turn the structure of vegetation canopies regulate water partitioning into interception, throughfall and steam flow. Such spatial differences in inputs, together with complex patterns of water uptake from distributed root networks can create marked heterogeneity in soil moisture dynamics at small scales. Traditional methods of monitoring soil moisture have revolved around limited point measurements, but improved geophysical techniques have facilitated a trend towards more spatially distributed measurements to help understand this heterogeneity. Here, we present a study using 3D ERT surveys in a 3.2km upland catchment in the Scottish Highlands where increasing afforestation (for climate change adaptation, biofuels and conservation) has the potential to increase interception losses and reduce soil moisture storage. The study combined 3D surveys, traditional point measurements and laboratory analysis of soil cores to assess the plot scale soil moisture dynamics in podzolic soils under forest stands of 15m high Scots pine (Pinus sylvestris) and adjacent non-forest plots dominated by heather (Calluna vulgaris) shrubs (<0.5m high). These dominant species are typical of forest and non-forest vegetation communities the Scottish Highlands. Results showed differences in the soil moisture dynamics under the different vegetation types, with heterogeneous patterns in the forested site mainly correlated with canopy cover and mirroring interception losses. Temporal variability in the forested site was greater, probably due to the interception, and increased evapotranspiration losses relative to the

  6. Uses and limitations of the soil survey in hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Brooks, E.; Boll, J.

    2009-12-01

    One of the greatest challenges in hydrologic modeling is characterizing the effects of soil structure of hydrologic flow paths in complex watersheds. The Predictions in Ungauged Basins (PUB) initiative is pushing scientists to come up with innovative ways to reduce model calibration and predictive uncertainty and improve process understanding. Some of these innovative approaches have included incorporating ‘soft data’ as information for developing conceptual watershed frameworks and guiding calibration. In this study we examine the uses and limitations of the soil survey in hydrologic modeling. County soil surveys were initiated in 1899 and now digital maps are available throughout most of the US. Although these surveys were initially meant to guide selection and development of land, these surveys now include a great wealth of information from specific physical properties to indicators of saturation and development of perched water tables. To what degree does the information in the soil survey improve understanding of dominant hydrologic processes in a watershed? At what point must a hydrologist exercise discretion in using this information? We will discuss the extent to which the soil survey can be used to 1.) conceptualize the basic hydrology of a watershed, 2.) provide input data to a process-based hydrologic model, and 3.) validate spatial predictions of runoff and erosion from distributed hydrologic models. We will demonstrate each of these uses through case studies from multiple ecological regions across the country.

  7. Coupling of soil prokaryotic diversity and plant diversity across latitudinal forest ecosystems

    NASA Astrophysics Data System (ADS)

    Wang, Jun-Tao; Zheng, Yuan-Ming; Hu, Hang-Wei; Li, Jing; Zhang, Li-Mei; Chen, Bao-Dong; Chen, Wei-Ping; He, Ji-Zheng

    2016-01-01

    The belowground soil prokaryotic community plays a cardinal role in sustaining the stability and functions of forest ecosystems. Yet, the nature of how soil prokaryotic diversity co-varies with aboveground plant diversity along a latitudinal gradient remains elusive. By establishing three hundred 400-m2 quadrats from tropical rainforest to boreal forest in a large-scale parallel study on both belowground soil prokaryote and aboveground tree and herb communities, we found that soil prokaryotic diversity couples with the diversity of herbs rather than trees. The diversity of prokaryotes and herbs responds similarly to environmental factors along the latitudinal gradient. These findings revealed that herbs provide a good predictor of belowground biodiversity in forest ecosystems, and provide new perspective on the aboveground and belowground interactions in forest ecosystems.

  8. [Soil moisture dynamics in forest land and wasteland of Loess Plateau].

    PubMed

    Sun, C; Huang, B; Liu, S; Chen, H

    2000-08-01

    The dynamics of soil moisture stored in a wasteland and in a forest land in the sub-humid climate region of the Loess Plateau was measured with neutron moisture meter for three successive years. Within the depth of 0-320 cm, the increment of soil water in the test 3 years was respectively -165.7 mm, -15.2 mm and -115.2 mm at the upper and lower position on north slopes and the lower position on south slope of the wasteland. Soil water increased by 17.2 mm at the upper position on north slope of the Chinese pine forest land, after > 380 mm water was consumed yearly by tree transpiration. It is suggested that forest land is essentially different from wasteland in soil water income/expense. The necessity of conducting the approaches for gaining available water of forest land was put forward. PMID:11767669

  9. Coupling of soil prokaryotic diversity and plant diversity across latitudinal forest ecosystems

    PubMed Central

    Wang, Jun-Tao; Zheng, Yuan-Ming; Hu, Hang-Wei; Li, Jing; Zhang, Li-Mei; Chen, Bao-Dong; Chen, Wei-Ping; He, Ji-Zheng

    2016-01-01

    The belowground soil prokaryotic community plays a cardinal role in sustaining the stability and functions of forest ecosystems. Yet, the nature of how soil prokaryotic diversity co-varies with aboveground plant diversity along a latitudinal gradient remains elusive. By establishing three hundred 400-m2 quadrats from tropical rainforest to boreal forest in a large-scale parallel study on both belowground soil prokaryote and aboveground tree and herb communities, we found that soil prokaryotic diversity couples with the diversity of herbs rather than trees. The diversity of prokaryotes and herbs responds similarly to environmental factors along the latitudinal gradient. These findings revealed that herbs provide a good predictor of belowground biodiversity in forest ecosystems, and provide new perspective on the aboveground and belowground interactions in forest ecosystems. PMID:26781165

  10. Coupling of soil prokaryotic diversity and plant diversity across latitudinal forest ecosystems.

    PubMed

    Wang, Jun-Tao; Zheng, Yuan-Ming; Hu, Hang-Wei; Li, Jing; Zhang, Li-Mei; Chen, Bao-Dong; Chen, Wei-Ping; He, Ji-Zheng

    2016-01-01

    The belowground soil prokaryotic community plays a cardinal role in sustaining the stability and functions of forest ecosystems. Yet, the nature of how soil prokaryotic diversity co-varies with aboveground plant diversity along a latitudinal gradient remains elusive. By establishing three hundred 400-m(2) quadrats from tropical rainforest to boreal forest in a large-scale parallel study on both belowground soil prokaryote and aboveground tree and herb communities, we found that soil prokaryotic diversity couples with the diversity of herbs rather than trees. The diversity of prokaryotes and herbs responds similarly to environmental factors along the latitudinal gradient. These findings revealed that herbs provide a good predictor of belowground biodiversity in forest ecosystems, and provide new perspective on the aboveground and belowground interactions in forest ecosystems. PMID:26781165

  11. soil carbon pools within oak forest is endangered by global climate change in central mexico

    NASA Astrophysics Data System (ADS)

    García-Oliva, Felipe; Merino, Agustín; González-Rodriguez, Antonio; Chávez-Vergara, Bruno; Tapia-Torres, Yunuen; Oyama, Ken

    2016-04-01

    Forest soil represents the main C pool in terrestrial ecosystems. In particular, temperate forest ecosystems play an important role in the C budget among tropical countries, such as Mexico. For example, the temperate forest ecosystem contains higher C contents on average (295 Mg C ha-1) than the soil C associated with other ecosystems in Mexico (between 56 to 287 Mg C ha-1). At a regional scale, oak forest has the highest C content (460 Mg C ha-1) among the forest ecosystem in Michoacán State at Central Mexico. At the local scale, the soil C content is strongly affected by the composition of organic matter produced by the plant species. The oak species are very diverse in Mexico, distributed within two sections: Quercus sensu stricto and Lobatae. The oak species from Quercus s.s. section produced litterfall with lower concentrations of recalcitrant and thermostable compounds than oak species from Lobatae section, therefore the soil under the former species had higher microbial activity and nutrient availability than the soil under the later species. However, the forest fragment with higher amount of oak species from Quercus s.s. section increases the amount of soil C contents. Unfortunately, Quercus species distribution models for the central western region of Mexico predict a decrease of distribution area of the majority of oak species by the year 2080, as a consequence of higher temperatures and lower precipitation expected under climate change scenarios. Additionally to these scenarios, the remnant oak forest fragments suffer strong degradation due to uncontrolled wood extraction and deforestation. For this reason, the conservation of oak forest fragments is a priority to mitigate the greenhouse gases emission to the atmosphere. In order to enhance the protection of these forest fragments it is required that the society identify the ecosystem services that are provided by these forest fragments.

  12. Distinctive Tropical Forest Variants Have Unique Soil Microbial Communities, But Not Always Low Microbial Diversity

    PubMed Central

    Tripathi, Binu M.; Song, Woojin; Slik, J. W. F.; Sukri, Rahayu S.; Jaafar, Salwana; Dong, Ke; Adams, Jonathan M.

    2016-01-01

    There has been little study of whether different variants of tropical rainforest have distinct soil microbial communities and levels of diversity. We compared bacterial and fungal community composition and diversity between primary mixed dipterocarp, secondary mixed dipterocarp, white sand heath, inland heath, and peat swamp forests in Brunei Darussalam, Northwest Borneo by analyzing Illumina Miseq sequence data of 16S rRNA gene and ITS1 region. We hypothesized that white sand heath, inland heath and peat swamp forests would show lower microbial diversity and relatively distinct microbial communities (compared to MDF primary and secondary forests) due to their distinctive environments. We found that soil properties together with bacterial and fungal communities varied significantly between forest types. Alpha and beta-diversity of bacteria was highest in secondary dipterocarp and white sand heath forests. Also, bacterial alpha diversity was strongly structured by pH, adding another instance of this widespread pattern in nature. The alpha diversity of fungi was equally high in all forest types except peat swamp forest, although fungal beta-diversity was highest in primary and secondary mixed dipterocarp forests. The relative abundance of ectomycorrhizal (EcM) fungi varied significantly between forest types, with highest relative abundance observed in MDF primary forest. Overall, our results suggest that the soil bacterial and fungal communities in these forest types are to a certain extent predictable and structured by soil properties, but that diversity is not determined by how distinctive the conditions are. This contrasts with the diversity patterns seen in rainforest trees, where distinctive soil conditions have consistently lower tree diversity. PMID:27092105

  13. Distinctive Tropical Forest Variants Have Unique Soil Microbial Communities, But Not Always Low Microbial Diversity.

    PubMed

    Tripathi, Binu M; Song, Woojin; Slik, J W F; Sukri, Rahayu S; Jaafar, Salwana; Dong, Ke; Adams, Jonathan M

    2016-01-01

    There has been little study of whether different variants of tropical rainforest have distinct soil microbial communities and levels of diversity. We compared bacterial and fungal community composition and diversity between primary mixed dipterocarp, secondary mixed dipterocarp, white sand heath, inland heath, and peat swamp forests in Brunei Darussalam, Northwest Borneo by analyzing Illumina Miseq sequence data of 16S rRNA gene and ITS1 region. We hypothesized that white sand heath, inland heath and peat swamp forests would show lower microbial diversity and relatively distinct microbial communities (compared to MDF primary and secondary forests) due to their distinctive environments. We found that soil properties together with bacterial and fungal communities varied significantly between forest types. Alpha and beta-diversity of bacteria was highest in secondary dipterocarp and white sand heath forests. Also, bacterial alpha diversity was strongly structured by pH, adding another instance of this widespread pattern in nature. The alpha diversity of fungi was equally high in all forest types except peat swamp forest, although fungal beta-diversity was highest in primary and secondary mixed dipterocarp forests. The relative abundance of ectomycorrhizal (EcM) fungi varied significantly between forest types, with highest relative abundance observed in MDF primary forest. Overall, our results suggest that the soil bacterial and fungal communities in these forest types are to a certain extent predictable and structured by soil properties, but that diversity is not determined by how distinctive the conditions are. This contrasts with the diversity patterns seen in rainforest trees, where distinctive soil conditions have consistently lower tree diversity. PMID:27092105

  14. Definition of spectrally separable classes for soil survey research

    NASA Technical Reports Server (NTRS)

    Cipra, J. E.; Swain, P. H.; Gill, J. H.; Baumgardner, M. F.; Kristof, S. J.

    1972-01-01

    A procedure is outlined for defining spectral classes such that the differences between classes can be quantified. It also facilitates determination of a number of classes such that the classes are spectrally discriminable. This is accomplished by partitioning the data into many classes and then combining similar spectral classes on the basis of appropriate criteria. Multispectral data were collected over a 12-mile flightline in White County, Indiana, in connection with the 1971 Corn Blight Watch Experiment. Data were collected in May by the University of Michigan airborne scanning spectrometer at an altitude of 5000 feet. Spectral maps resulting from the analysis were compared to existing soil surveys of the National Cooperative Soil Survey. The method should help determine the extent to which spectral properties of soil surfaces can be associated with morphologic and topographic differences of interest to soil surveyors engaged in operational soil mapping.

  15. Global Survey of Anthropogenic Neighborhood Threats to Conservation of Grass-Shrub and Forest Vegetation

    EPA Science Inventory

    We report a survey of land cover patterns focusing on forest, grassland, and shrubland for the United States. To provide information for a national resource assessment, an integrated survey of patterns was conducted using a circa 2001 land cover map. The survey was designed to ac...

  16. Forest Landowner Education Interests and Delivery Preferences: A Retrospective Look at Survey Results and Actual Participation

    ERIC Educational Resources Information Center

    Zobrist, Kevin W.; Rozance, Mary Ann

    2015-01-01

    This article presents survey data on education interests and delivery preferences of small forest landowners in Washington and compares it to actual program participation over 6 years. The survey was conducted in late 2007 to guide development and implementation of a Extension forestry program. The survey found broad interest across many topics…

  17. Biological soil crusts reduce soil erosion in early successional subtropical forests in PR China

    NASA Astrophysics Data System (ADS)

    Seitz, Steffen; Goebes, Philipp; Käppeler, Kathrin; Nebel, Martin; Webber, Carla; Scholten, Thomas

    2016-04-01

    Biological soil crusts (BSCs) have major influences on terrestrial ecosystems and play significant functional roles in soil systems, such as accelerating soil formation, changing water flows or enhancing soil stability. By that, they have the potential to protect soil surfaces against erosive forces by wind or water. However, the effect of BSCs on erosion processes is rarely mentioned in literature and most of the work done focused on arid and semi-arid environments. Furthermore, compared to the structure and function of BSCs, less attention was paid to their temporal and topographical distribution. This study aims to investigate the influence of BSCs on initial soil erosion, and their topographical development over time in initial subtropical forest ecosystems. Therefore, measurements have been conducted within a biodiversity and ecosystem functioning experiment (BEF China) near Xingangshan, Jiangxi Province, PR China. Interrill erosion was measured on 220 microscale run-off plots (ROPs, 0.4 m × 0.4 m) and the occurrence, distribution and development of BSCs within the measuring setup were recorded. BSC cover in each ROP was determined photogrammetrically in four time steps (autumn 2011, summer 2012, summer 2013 and summer 2014). BSC species were identified by morphological characteristics and classified to higher taxonomic levels. Higher BSC cover led to reduced sediment discharge and runoff volume due to its protection against splash energy, the adherence of soil particles and enhanced infiltration. Canopy ground cover and leaf area index had a positive effect on the development of BSC cover at this initial stage of the forest ecosystem. Moreover, BSC cover decreased with increasing slope, as we presume that developing BSCs are washed away more easily at steep gradients. Elevation and aspect did not show an influence. BSCs in this study were moss-dominated and 26 different moos species were found. Mean BSC cover on ROPs was 14 % in the 3rd year of the tree

  18. Characteristics of spatial variability in soil CO2 efflux in a Moso bamboo (Phyllostachys pubescens) forest

    NASA Astrophysics Data System (ADS)

    Lin, Meng Ying; Hsieh, Yi-Fang; Kume, Tomonori; Cheng, Chih-Hsin

    2014-05-01

    The expansion of bamboo forest to surrounding ecosystems in eastern Asian countries such as Taiwan can alter the carbon balance, in which soil CO2 efflux is an essential component. Spatial heterogeneity of soil CO2 efflux in forested ecosystems is essential not only for understanding CO2 dynamics but also for suitable sampling design to estimate annual soil CO2 efflux and the response to environmental changes. The aim of this study is to understand characteristics of spatial variability of soil CO2 efflux in a bamboo forest, situated in a montane cloud forest of central Taiwan. To this end, this study 1) evaluated the seasonal changes in spatial variability in soil respiration in Moso bamboo (Phyllostachys pubescens) forest through one year and 2) quantified the spatial variation of soil CO2 efflux in this stand using the semivariance. We measured soil CO2 efflux using the closed dynamic chamber method with an infrared gas analyzer (PP system, EGM-4) once a month from April 2012 to November 2013. The semivariance was used to quantify the spatial variability of soil CO2 efflux. In this study, we found spatially averaged soil CO2 efflux during each measurement campaign varied from 1.54 to 4.98 µmol CO2 m-2 s-1, which was larger in bamboo sprouting period (April to August) than other months (September to March). The average coefficient of variation (CV) of the soil CO2 effluxes was 46.4%. Our CV was comparable to that in other tropical forests. The semivariogram revealed that there was autocorrelation of soil CO2 effluxes, and the scale was significantly different between bamboo sprouting period and the other periods. The spatial distribution map showed temporal changes in soil CO2 efflux, and the fairly conservative spatial patterns in soil CO2 effluxes were found through the year in our site. On the other the hand, the range of autocorrelation was much larger in April (33.4 m - 123 m) than other months (2.4m - 5.5m). This indicated that considering a long distance

  19. Asticcacaulis solisilvae sp. nov., isolated from forest soil.

    PubMed

    Kim, Seil; Gong, Gyeongtaek; Park, Tai Hyun; Um, Youngsoon

    2013-10-01

    An obligately aerobic, chemoheterotrophic, mesophilic prosthecate bacterium, designated strain CGM1-3EN(T), was isolated from the enrichment cultures of forest soil from Cheonggyesan Mountain, Republic of Korea. Cells were Gram-reaction-negative, motile rods (1.3-2.4 µm long by 0.30-0.75 µm wide) with single flagella. The strain grew at 10-37 °C (optimum 25-30 °C) and at pH 4.5-9.5 (optimum 5.0-7.0). The major cellular fatty acids were C16 : 0, C18 : 1ω7c 11-methyl, C12 : 1 3-OH and summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c). The genomic DNA G+C content of strain CGM1-3EN(T) was 63.7 mol%. The closest phylogenetic neighbour to strain CGM1-3EN(T) was identified as Asticcacaulis biprosthecium DSM 4723(T) (97.2 % 16S rRNA gene sequence similarity) and the DNA-DNA hybridization value between strain CGM1-3EN(T) and A. biprosthecium DSM 4723(T) was less than 24.5 %. Strain CGM1-3EN(T) used d-glucose, d-fructose, sucrose, maltose, trehalose, d-mannose, d-mannitol, d-sorbitol, d-galactose, cellobiose, lactose, raffinose, fumarate, pyruvate, dl-alanine and glycerol as carbon sources. Based on data from the present polyphasic study, the forest soil isolate CGM1-3EN(T) is considered to represent a novel species of the genus Asticcacaulis, for which the name Asticcacaulis solisilvae sp. nov. is proposed. The type strain is CGM1-3EN(T) ( = AIM0088(T) = KCTC 32102(T) = JCM 18544(T)). PMID:23687055

  20. Remote sensing-based estimation of annual soil respiration at two contrasting forest sites

    SciTech Connect

    Gu, Lianhong; Huang, Ni; Black, T. Andrew; Wang, Li; Niu, Zheng

    2015-11-23

    Soil respiration (Rs), an important component of the global carbon cycle, can be estimated using remotely sensed data, but the accuracy of this technique has not been thoroughly investigated. In this article, we proposed a methodology for the remote estimation of annual Rs at two contrasting FLUXNET forest sites (a deciduous broadleaf forest and an evergreen needleleaf forest).

  1. Temporal change in soil carbon stability at a paired old-growth douglas-fir forest/clear-cut site

    EPA Science Inventory

    Forest ecosystems are estimated to contain one-half of the total terrestrial carbon (C) pool (1146 Pg), with two-thirds of this C (787 Pg) residing in forest soils. Given the magnitude of this C pool, it is critical to understand the effects of forest management practices on soil...

  2. Production of nitrous oxide and consumption of methane by forest soils

    NASA Technical Reports Server (NTRS)

    Keller, M.; Wofsy, S. C.; Kaplan, W. A.; Mcelroy, M. B.; Goreau, T. J.

    1983-01-01

    Soils in an Amazonian rainforest are observed to release N2O at a rate larger than the global mean by about a factor of 20. Emissions from a New England hardwood forest are approximately 30 times smaller then Brazilian values. Atmospheric methane is consumed by soils in both systems. Tropical forests would provide a major source of atmospheric N2O if the Brazilian results are representative.

  3. Invasive and exotic earthworms: an unaccounted change to mercury cycling in northeastern US forest soils

    NASA Astrophysics Data System (ADS)

    Richardson, J. B.; Friedland, A. J.; Görres, J. H.; Renock, D. J.; Jackson, B. P.

    2014-12-01

    Invasive and exotic earthworms are now present in many forested areas of the northeastern US with currently unquantified consequences to abiotic and biotic Hg cycling. To quantify these effects, we measured Hg concentrations (mg kg-1) and amounts (μg m-2) in earthworms and soil horizons at 45 soil pits from 9 sites in northern New England. Seven earthworm species were observed in varying assemblages. Most earthworm species attained concentrations of Hg potentially hazardous to wildlife that may ingest them, with highest concentrations found in shallow-burrowing, litter-feeders. Specifically, Aporrectodea rosea and Amynthas agrestis had the greatest Hg concentrations (0.9 ± 0.1) and Hg amounts (8 ± 2) μg m-2. Aporrectodea rosea and Amynthas agrestis were found to inhabit the forest floor and the top 5 cm of the mineral horizons in high abundance, potentially making it a readily accessible prey species. Bioaccumulation of Hg by invasive and exotic earthworms may be an important mechanism that transfers Hg to ground foraging predators, such as thrushes, red-backed salamanders and foxes, which is generally unaccounted for in terrestrial food chains. Earthworm Hg concentrations were poorly correlated with their respective soil Hg concentrations, suggesting a species dependence for Hg bioaccumulation rather than site effects. We observed that forest floor Hg concentrations and amounts were 23% and 57% lower, respectively, at soil pits with earthworms compared to those without. Moreover, Hg amounts in forest floor-feeding earthworms exceeded the remaining forest floor Hg pools. Mercury concentrations and pools in the mineral soil were 21% and 33% lower, respectively, for soil pits with earthworms compared to those without. We hypothesize that enhanced decomposition, horizon disturbance and bioaccumulation by earthworms has decreased Hg amounts in the forest floor and mineral soil. Our results suggest that earthworms are decreasing Hg storage in forest soils with

  4. Detrimental Influence of Invasive Earthworms on North American Cold-Temperate Forest Soils

    ERIC Educational Resources Information Center

    Enerson, Isabel

    2012-01-01

    The topic of invasive earthworms is a timely concern that goes against many preconceived notions regarding the positive benefits of all worms. In the cold-temperate forests of North America invasive worms are threatening forest ecosystems, due to the changes they create in the soil, including decreases in C:N ratios and leaf litter, disruption of…

  5. Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis

    USGS Publications Warehouse

    Laughlin, D.C.; Abella, S.R.; Covington, W.W.; Grace, J.B.

    2007-01-01

    Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive effect of richness on plant cover. Richness was strongly related to soil nitrogen in the model, with evidence for both a direct negative effect and an indirect non-linear relationship mediated through understory plant cover. Soil organic matter appeared to have a positive influence on understory richness that was independent of soil nitrogen. Richness was lowest where the forest overstory was densest, which can be explained through indirect effects on soil organic matter, soil nitrogen and understory cover. Finally, model results suggest a variety of direct and indirect processes whereby mineral soil properties can influence richness. Conclusions: Understory plant species richness and plant cover in P. ponderosa forests appear to be significantly influenced by soil organic matter and nitrogen, which are, in turn, related to overstory density and composition and mineral soil properties. Thus, soil properties can impose direct and indirect constraints on local species diversity in ponderosa pine forests. ?? IAVS; Opulus Press.

  6. Greenhouse Gas Fluxes from Deciduous and Boreal Forest Soils in Eastern Canada

    NASA Astrophysics Data System (ADS)

    Ullah, S.; Moore, T.

    2012-04-01

    The exchange of the important trace gases, methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2), between forested soils and the atmosphere can show great temporal and spatial variability. We investigated the fluxes of CH4, N2O, and CO2 from deciduous and boreal forest soils in eastern Canada from 2006 to 2008 in 20 sites representative of different soil drainage classes, management schemes and natural disturbance. Well-drained soils consumed atmospheric CH4, while poorly-drained 'cryptic' wetland soils embedded in depressions were a source. CH4 fluxes could be predicted primarily by temperature and moisture, and tree cover exerted an influence mainly through the creation of large soil porosity, leading to increased consumption rates. In contrast, there were very poor relationships between N2O fluxes and environmental variables, reflecting the complex microbial, edpahic and N cycling processes, such as nitrification in well-drained soils and denitrification in poorly-drained soils, which lead to N2O production (or consumption) in soils. At the broad temporal and spatial scale, however, soil C:N ratio was a good predictor of N2O emission rates, through its influence upon N cycling processes. Soil CO2 emission rates showed less spatial and temporal variability, and were controlled by temperature and moisture. Poorly-drained soils in these forests play a critical role in the net global warming potential of forested landscapes. Therefore, soil drainage class integrates many of the biogeochemical processes controlling the flux of these gases and provides a framework for extrapolating results spatially and currently we are developing an estimate of the flux of these gases for the forest regions of Canada.

  7. The impact of tropical forest logging and oil palm agriculture on the soil microbiome.

    PubMed

    Tripathi, Binu M; Edwards, David P; Mendes, Lucas William; Kim, Mincheol; Dong, Ke; Kim, Hyoki; Adams, Jonathan M

    2016-05-01

    Selective logging and forest conversion to oil palm agriculture are rapidly altering tropical forests. However, functional responses of the soil microbiome to these land-use changes are poorly understood. Using 16S rRNA gene and shotgun metagenomic sequencing, we compared composition and functional attributes of soil biota between unlogged, once-logged and twice-logged rainforest, and areas converted to oil palm plantations in Sabah, Borneo. Although there was no significant effect of logging history, we found a significant difference between the taxonomic and functional composition of both primary and logged forests and oil palm. Oil palm had greater abundances of genes associated with DNA, RNA, protein metabolism and other core metabolic functions, but conversely, lower abundance of genes associated with secondary metabolism and cell-cell interactions, indicating less importance of antagonism or mutualism in the more oligotrophic oil palm environment. Overall, these results show a striking difference in taxonomic composition and functional gene diversity of soil microorganisms between oil palm and forest, but no significant difference between primary forest and forest areas with differing logging history. This reinforces the view that logged forest retains most features and functions of the original soil community. However, networks based on strong correlations between taxonomy and functions showed that network complexity is unexpectedly increased due to both logging and oil palm agriculture, which suggests a pervasive effect of both land-use changes on the interaction of soil microbes. PMID:26994316

  8. Carbon Dynamics of Forest Floor and Stem in Black Spruce Forest Soils, Interior Alaska

    NASA Astrophysics Data System (ADS)

    Kim, Yongwon; Kim, Seong-Deog; Kim, Woongji

    2010-05-01

    Our automated open/close chamber system (AOCC) consists of eight chambers, a pump, CO2 gas analyzer, and a datalogger for CO2 data on the lichen, tussock, feather moss, and sphagnum moss of a black spruce forest, Interior Alaska, during the growing seasons of 2007 and 2008. During the observing periods of 2007 and 2008, the seasonal NEE was 0.127±0.049 and -0.039±0.025 mgCO2/m2/s in tussock regime, and 0.006±0.011 and 0.028±0.017 mgCO2/m2/s in sphagnum moss, respectively. Air temperature is a more significant regulator than soil temperature in determining the GPP and Re of forest floor vegetations. Air temperature explained 77-95% of the variability in GPP and Re of the floor vegetations. The contributions (%) of simulated seasonal GPP to the black spruce forest during non-growing periods (DOY 1-120 and 244-365) and during the growing period (DOY 121-243) of 2007 are 63-72%, 20-25%, and 8-18%, respectively. This indicates that the floor CO2 exchange, as well as the contribution of winter carbon emission, is a component of the regional carbon budget that cannot be neglected. As the result of simulated GPP and Re in tussock during 2007, tussocks are found to have on atmospheric CO2 release, similar to results of observation for 63-day of 2007. On the other hand of stem respiration rates of black spruce (Picea Mariana), the continuous measurement of stem respiration was conducted in black spruce stands of different ages (4.3 to 13.5 cm in DBH) in Interior Alaska during the growing seasons of 2007 and 2008, using a pump, CO2 analyzer, chambers, and data-logger. The averaged whole stem respiration rate is 0.011±0.005 mgCO2/m2/s (range 0.005±0.002 to 0.015±0.008 mgCO2/m2/s, CV 45%) in black spruce stands, indicating remarkably diurnal and seasonal variations of stem respiration among the stems during the growing season. It is found that metabolism exhibits 1.5-fold higher in the younger black spruce stand than in the older. Temperatures in the air and stem are

  9. Relationships among forest soil C isotopic composition, partitioning, and turnover times

    SciTech Connect

    Garten Jr, Charles T

    2006-09-01

    The purpose of this research was to test the hypothesis that vertical enrichment of soil {delta}{sup 13}C values is related to rates of soil C turnover in undisturbed, mature forest ecosystems. Soil C and N were measured at nine sites along an altitudinal gradient in the southern Appalachian Mountains (Tennessee and North Carolina, USA). Measurements indicated greater labile and total soil C stocks with increasing altitude. Laboratory incubations (3 days) of rewetted, air-dry soils indicated potential soil C mineralization ({micro}g CO{sub 2} produced {center_dot} g{sup -1} soil C) declined with elevation. A principal component analysis indicated N availability increased with altitude. At each site, there was a significant relationship between {delta}{sup 13}C and log-transformed C concentrations in the soil profile (30 cm deep). Enrichment factors ({var_epsilon}) from the Rayleigh equation were also equally useful for describing soil {delta}{sup 13}C profiles at each site. Soil C partitioning and turnover times along the gradient were correlated with {sup 13}C-enrichment factors. Greater rates of change in {delta}{sup 13}C through the soil profile were correlated with faster soil C turnover. Environmental factors, soil C partitioning, and the rate of vertical change in soil {sup 13}C abundance are interrelated such that {delta}{sup 13}C measurements are a potential indicator of C dynamics in undisturbed forest soils.

  10. Snow removal and ambient air temperature effects on forest soil temperatures in northern Vermont

    NASA Astrophysics Data System (ADS)

    Wang, D.; Decker, K. L.; Waite, C.; Scherbatskoy, T.

    2003-12-01

    We measured deciduous forest soil temperatures under control (unmanipulated) and snow-free (where snow is manually removed) conditions for four winters (at three soil depths) to determine effects of a snow cover reduction such as may occur as a result of climate change on Vermont forest soils. The four winters we studied were characterized as:`cold and snowy', `warm with low snow', `cold with low snow', and `cool with low snow'. Snow-free soils were colder than controls at 5 and 15 cm depth for all years, and at all depths in the two cold winters. Soil thermal variability generally decreased with both increased snow cover and soil depth. The effect of snow cover on soil freeze-thaw events was highly dependent on both the depth of snow and the soil temperature. Snow kept the soil warm and reduced soil temperature variability, but often this caused soil to remain near 0 deg C, resulting in more freeze-thaw events under snow at one or more soil depths. During the `cold snowy' winter, soils under snow had daily averages consistently >0 deg C, whereas snow-free soil temperatures commonly dropped below -3 deg C. During the `warm' year, temperatures of soil under snow were often lower than those of snow-free soils. The warmer winter resulted in less snow cover to insulate soil from freezing in the biologically active top 30 cm. The possible consequences of increased soil freezing include more root mortality and nutrient loss which would potentially alter ecosystem dynamics, decrease productivity of some tree species, and increase sugar maple mortality in northern hardwood forests.

  11. Trends in soil-vegetation dynamics in burned Mediterranean pine forests: the effects of soil properties

    NASA Astrophysics Data System (ADS)

    Wittenberg, L.; Malkinson, D.

    2009-04-01

    Fire can impact a variety of soil physical and chemical properties. These changes may result, given the fire severity and the local conditions, in decreased infiltration and increased runoff and erosion rates. Most of these changes are caused by complex interactions among eco-geomorphic processes which affect, in turn, the rehabilitation dynamics of the soil and the regeneration of the burnt vegetation. Following wildfire events in two forests growing on different soil types, we investigated runoff, erosion, nutrient export (specifically nitrogen and phosphorous) and vegetation recovery dynamics. The Biriya forest site, burned during the 2006 summer, is composed of two dominant lithological types: soft chalk and marl which are relatively impermeable. The rocks are usually overlain by relatively thick, up of to 80 cm, grayish-white Rendzina soil, which contains large amounts of dissolved carbonate. These carbonates serve as a limiting factor for vegetation growth. The planted forest in Biriya is comprised of monospecific stands of Pinus spp. and Cupressus spp. The Mt. Carmel area, which was last burned in the 2005 spring, represents a system of varied Mediterranean landscapes, differentiated by lithology, soils and vegetation. Lithology is mainly composed of limestone, dolomite, and chalk. The dominant soil is Brown Rendzina whilst in some locations Grey Rendzina and Terra Rossa can be found. The local vegetation is composed mainly of a complex of pine (Pinus halepensis), oak (Quercus calliprinos), Pistacia lentiscus and associations At each site several 3X3 m monitoring plots were established to collect runoff and sediment. In-plot vegetation changes were monitored by a sequence of aerial photographs captured using a 6 m pole-mounted camera. At the terra-rosa sites (Mt. Carmel) mean runoff coefficients were 2.18% during the first year after the fire and 1.6% in the second. Mean erosion rates also decreased, from 42 gr/m2 to 4 gr/m2. The recovering vegetation was

  12. Soil microbiological composition and its evolution along with forest succession in West Siberia

    NASA Astrophysics Data System (ADS)

    Naplekova, Nadezhda N.; Malakhova, Nataliya A.; Maksyutov, Shamil

    2015-04-01

    Natural forest succession process in West Siberia is mostly initiated by fire disturbance and involves changing tree species composition from pioneer species to late succession trees. Along with forest aging, litter and forest biomass accumulate. Changes of the soil nitrogen cycle between succession stages, important for plant functioning, have been reported in a number of studies. To help understanding the mechanism of the changes in the soil nitrogen cycle we analyzed soil microbiological composition for soil profiles (0-160 cm) taken at sites corresponding to three forest succession stages: (1) young pine, age 18-20 years, (2) mid age, dark coniferous, age 50-70 years, (3) mature, fir-spruce, age 170-180 years. Soil samples were taken from each soil horizon and analyzed in the laboratory for quantity and species composition of algae and other microorganisms. Algae community at all stages of succession is dominated by species typical for forest (pp. Chlorhormidium, Chlamydomonas, Chloroccocum, Pleurochloris, Stichococcus). Algae species composition is summarized by formulas: young forest C14X10Ch9H2P4Cf1B2amph4, mid age X16C15Ch10H4P4Cf1B2amph4, mature X24C22Ch17H10P2amph5Cf1, with designations C -- Cyanophyta, X -- Xantophyta, Ch -- Chlorophyta, B -- Bacillariophyta. Diversity is highest in upper two horizons and declines with depth. Microorganism composition on upper 20 cm was analyzed in three types of forests separately for consumers of protein (ammonifiers) and mineral nitrogen, fungi, azotobacter, Clostridium pasteurianum, oligonitrophylic (eg diazotrophs), nitrifiers and denitrifiers. Nitrogen biologic fixation in the mature forest soils is done mostly by oligonitrophyls and microorganisms of the genus Clostridium as well as сyanobacteria of sp. Nostoc, but the production rate appears low. Concentrations (count in gram soil) of nitrogen consumers (eg ammonifiers), oligonitrophyls, Clostridium and denitrifiers increase several fold from young forest to mid

  13. Wildfire and forest disease interaction lead to greater loss of soil nutrients and carbon.

    PubMed

    Cobb, Richard C; Meentemeyer, Ross K; Rizzo, David M

    2016-09-01

    Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of disease/no disease and burned/unburned conditions in both forest types. Forest floor organic matter and associated nutrients were greater in unburned redwood compared to unburned mixed evergreen forests. Post-fire element pools were similar between forest types, but lower in burned-invaded compared to burned-uninvaded plots. We found evidence disease-generated fuels led to increased loss of forest floor C, N, Ca, and P. The same effects were associated with lower %C and higher PO4-P in the mineral soil. Fire-disease interactions were linear functions of pre-fire host mortality which was similar between the forest types. Our analysis suggests that these effects increased forest floor C loss by as much as 24.4 and 21.3 % in redwood and mixed evergreen forests, respectively, with similar maximum losses for the other forest floor elements. Accumulation of sudden oak death generated fuels has potential to increase fire-related loss of soil nutrients at the region-scale of this disease and similar patterns are likely in other forests, where fire and disease overlap. PMID:27164911

  14. Climatic factors and reindeer grazing -- the effects on soil carbon dynamics in subarctic boreal pine forest.

    NASA Astrophysics Data System (ADS)

    Köster, Kajar; Köster, Egle; Berninger, Frank; Pumpanen, Jukka

    2016-04-01

    Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in the northern ecosystems, affecting plant diversity, soil nutrient cycling and soil organic matter decomposition. Changes caused by reindeer in vegetation have indirect effects on physical features of the soil e.g. soil microclimate, root biomass and also on soil carbon dynamics. In a field experiment in Finnish Lapland, Värriö Strict Nature Reserve (67° 46' N, 29° 35' E) we investigated how the reindeer grazing in subarctic boreal forest combined with climate (air temperature and precipitation) affects soil temperature, soil water content, and ultimately the CO2 efflux from forest soils. The study was carried out in the growing seasons of the years 2013 and 2014, where 2013 was an extremely dry year (specially the summer), and the year 2014 was a "normal" year in means of precipitations. Our study areas are located in the northern boreal subarctic coniferous forest at the zone of the last intact forest landscapes in Fennoscandia, where large areas of relatively undisturbed subarctic Scots pine (Pinus sylvestris L.) forests can still be found. We established the experiment as a split plot experiment with 2 blocks and 5 sub-plots per treatment that were divided into grazed and non-grazed parts, separated with a fence. The sample plots are located along the borderline between Finland and Russia, where the ungrazed area was excluded from reindeer already in 1918, to prevent the Finnish reindeer from going to the Russian side and there are not many reindeer on Russian side of the area. Our study showed that in subarctic mature pine forests, soil temperatures were higher, and soil water content was fluctuating more on grazed areas compared to non-grazed areas in both years. In both years, the soil water content on the grazed area was highest in June. The situation changed somewhere in the second half of July when the moisture content in the non-grazed area was higher. We found

  15. Soil type as factor controlling the effects of forest transformation to agricultural use in soil aggregation and related properties

    NASA Astrophysics Data System (ADS)

    Chrenková, Katarína; Mataix-Solera, Jorge; Dlapa, Pavel; Arcenegui, Victoria

    2014-05-01

    The stability of aggregates has an important role in soil functioning and its behavior to avoid erosion and degradation, the ability to transfer liquids and gases, which are important features for crop production and ecosystem health (Tisdall and Oades, 1982). It's also a property that is highly influenced by land use and management (Angers et al., 1993). The stability of aggregates provides key information about the capacity of soil functions that defines the soil quality. This study has aimed to identify the long-term effects of forest transformation on agricultural use on soil structure and related properties. For the research was chosen seven localities in the Alicante Province (E Spain) with different soil types in all cases to compare how the land use changes can affect as a function of soil type and characteristics. In every site, samples were collected from agricultural land use (dry crops with tillage management), and in forest areas close to them with similar soil type that are used as references. On the samples, selected physical and chemical properties were analyzed such as Soil aggregate stability (AS), Organic matter (OM), Mean weight diameter (MWD) of aggregates and Water repellency (WR). As expected, in all cases the AS was significant lower in agricultural sites than in forest. But in some cases the differences were much higher than in others. In forest sites the AS varied between 46 to 82% while in agricultural sites ranged between 14 to 45%. The results showed strong positive correlation of AS with OM. The lowest initial values of AS were found in wettable sandy soils. The agricultural land use lead to relative decrease in AS by 39 to 79% compared to forest soils, indicating that some soils are much more vulnerable to land use than others. These differences can be explained mainly because intrinsic soil properties, such as OM content, texture, and WR. Particularly, the decrease in OM content and absence of WR are responsible for the decrease in

  16. Observation of Soil Water Repellency and pH soil change under Tropical Pine Plantations Compared with Native Tropical Forest

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Lebron, I.; Oatham, M. P.; Wuddivira, M. N.

    2011-12-01

    In temperate climates, soil water repellency (SWR) has been documented to develop with land-use change from native forest to pine plantations. In the tropics a sparse evidence base has been documented for the observation of SWR, but no investigation has been conducted to determine the consequences of changing land-use from native forest to pine plantations with regard to SWR. In our research we broaden the evidence base for tropical SWR by comparing the SWR behavior of seven tropical pine plantations in Trinidad with co-located native forest. We found that SWR occurred under both pine and native forest, but was more persistent and less heterogeneous under pine. The SWR was water content dependent with a threshold ~0.2 m3m-3, it showed a linear dependence with litter depth, and it was also found to be pH dependent, being higher in more acidic soils. The forest floor pH, contrary to convention for temperate climates, was observed to increase under some pine plantations, as compared with native tropical forest. This only occurred in the very acidic tropical soils (pH<4), but may have important biogeochemical consequences with regard to soil and water quality.

  17. Soil water repellency and pH soil change under tropical pine plantations compared with native tropical forest

    NASA Astrophysics Data System (ADS)

    Lebron, Inma; Robinson, David A.; Oatham, Mike; Wuddivira, Mark N.

    2012-01-01

    SummaryIn temperate climates, soil water repellency (SWR) has been documented to develop with land-use change from native forest to pine plantations. In the tropics a sparse evidence base has been documented for the observation of SWR, but no investigation has been conducted to determine the consequences of changing land-use from native forest to pine plantations with regard to SWR. In our research we broaden the evidence base for tropical SWR by comparing the SWR behavior of seven tropical pine plantations in Trinidad with co-located native forest. We found that SWR occurred under both pine and native forest, but was more persistent and less heterogeneous under pine. The SWR was water content dependent with a threshold ˜0.2 m 3 m -3, it showed a linear dependence with litter depth, and it was also found to be higher in more acidic soils. The forest floor pH, contrary to convention for temperate climates, was observed to increase under some pine plantations, as compared with native tropical forest. This only occurred in the very acidic tropical soils (pH < 4), but may have important biogeochemical consequences with regard to soil and water quality.

  18. History of Soil Survey and Evolution of the Brazilian Soil Classification System - SiBCS

    NASA Astrophysics Data System (ADS)

    Cunha dos Anjos, Lúcia Helena; Csekö Nolasco de Carvalho, Claudia; Homem Antunes, Mauro Antonio; Muggler, Cristine Carole

    2014-05-01

    In Brazil soil surveys started around 1940 and the first map with soil information of São Paulo State was published in 1943. The Committee of Soils of the National Service for Agronomic Research was created in 1947 by the Agriculture Ministry and became an historical landmark for soil survey in Brazil. In 1953, the National Program of soil survey was approved and the first soil map and report of Rio de Janeiro State was released in 1958, followed by São Paulo State in 1960. This is also the origin of Embrapa Soil Research institution. Other milestones were the soil surveys published by the Agronomic Institute of Campinas (IAC) and the natural resources studies published within the RADAMBRASIL Project, initially planned for the Amazon region and later covering the whole country. Many soil studies followed and a comprehensive knowledge of tropical soils was achieved resulting in successful technologies for agriculture production, in lands considered by many as of "low fertility and acid soils with limited or no agricultural potential". However, detailed soil surveys are still lacking; only 5% of the country soils are mapped in 1:25.000 scales, and 15-20% in 1:100.000. In the first soil survey reports of Rio de Janeiro (1958) and São Paulo (1960), soil classes were defined according to Baldwin, Kellog & Thorp (Yearbook of Agriculture for 1938), and Thorp & Smith (Soil Science, 67, 1949) publications. It was already clear that the existing classification systems were not adequate to represent the highly weathered tropical soils of the large old landscapes in the cerrado (savanna like) region, or the soils formed on recent hydromorphic conditions at the Amazon Basin and Pantanal region. A national classification system to embody the country's large territory and environmental variation from tropical to subtropical and semiarid conditions, as well as the diversity of soil forming processes in old and new landscapes had to be developed. In 1964, the first attempt of a

  19. EVALUATION OF A MEASUREMENT METHOD FOR FOREST VEGETATION IN A LARGE-SCALE ECOLOGICAL SURVEY

    EPA Science Inventory

    We evaluate a field method for determining species richness and canopy cover of vascular plants for the Forest Health Monitoring Program (FHM), an ecological survey of U.S. forests. Measurements are taken within 12 1-m2 quadrats on 1/15 ha plots in FHM. Species richness and cover...

  20. Into the Deep: Variability in Soil Microbial Communities and Carbon Turnover Along a Tropical Forest Soil Depth Profile

    NASA Astrophysics Data System (ADS)

    Pett-Ridge, J.; McFarlane, K. J.; Heckman, K. A.; Reed, S.; Wood, T. E.

    2015-12-01

    Tropical forest soils store more carbon (C) than any other terrestrial ecosystem and exchange vast amounts of CO2, water, and energy with the atmosphere. Much of this C is leached and stored within deeper soil layers, but we know exceedingly little about the fate of this C or the microbial communities that drive deep soil biogeochemistry. From the data that do exist, most organic matter (OM) in tropical soils appears associated with mineral particles, suggesting deep soils may provide greater C stabilization due to organo-metal co-precipitation and mineral-surface interactions. However, few studies have evaluated sub-surface soils in tropical ecosystems, the turnover times of deep soil C, and sensitivity of this C to global environmental change. To address this critical research need, we quantified C pools, microbial communities and soil radiocarbon turnover times in bulk soils and soil fractions [free light (unprotected), dense (mineral-associated)] from 0-140 cm in replicate soil pits in the Luquillo Experimental Forest, Puerto Rico. Unsurprisingly, we found soil C, nitrogen, and root and microbial biomass all declined exponentially with depth; total C stocks dropped from 5.5 % at the surface to <0.5% at 140cm depth. Soil OM 14C and mean turnover times were variable across replicate horizons, ranging from 3-1500 years at the surface (0-20 cm), to 5000-40,000 years at 140 cm depth. Soil C in the mineral associated fraction was much older than the free light fraction C, which reflected modern 14C at all depths. In comparison to temperate deciduous forests, these 14C values reflect far older soil C, and OM decomposition that highly favors free light C pools, even at depth. While previous work suggests these low C tropical subsoils contain small but metabolically active microbial communities at depths of ~100cm, these organisms appear highly OM limited, and preferentially degrade recent inputs. In the coming half century, tropical forests are predicted to see a 2 - 5

  1. Aspects of spatial and temporal aggregation in estimating regional carbon dioxide fluxes from temperate forest soils

    NASA Technical Reports Server (NTRS)

    Kicklighter, David W.; Melillo, Jerry M.; Peterjohn, William T.; Rastetter, Edward B.; Mcguire, A. David; Steudler, Paul A.; Aber, John D.

    1994-01-01

    We examine the influence of aggregation errors on developing estimates of regional soil-CO2 flux from temperate forests. We find daily soil-CO2 fluxes to be more sensitive to changes in soil temperatures (Q(sub 10) = 3.08) than air temperatures (Q(sub 10) = 1.99). The direct use of mean monthly air temperatures with a daily flux model underestimates regional fluxes by approximately 4%. Temporal aggregation error varies with spatial resolution. Overall, our calibrated modeling approach reduces spatial aggregation error by 9.3% and temporal aggregation error by 15.5%. After minimizing spatial and temporal aggregation errors, mature temperate forest soils are estimated to contribute 12.9 Pg C/yr to the atmosphere as carbon dioxide. Georeferenced model estimates agree well with annual soil-CO2 fluxes measured during chamber studies in mature temperate forest stands around the globe.

  2. Salvage logging effect on soil properties in a fire-affected Mediterranean forest: a two years monitoring research

    NASA Astrophysics Data System (ADS)

    Mataix-Solera, Jorge; Moltó, Jorge; Arcenegui, Vicky; García-Orenes, Fuensanta; Chrenkovà, Katerina; Torres, Pilar; Jara-Navarro, Ana B.; Díaz, Gisela; Izquierdo, Ezequiel

    2015-04-01

    In the Mediterranean countries, forest fires are common and must be considered as an ecological factor, but changes in land use, especially in the last five decades have provoked a modification in their natural regime. Moreover, post-fire management can have an additional impact on the ecosystem; in some cases, even more severe than the fire. Salvage logging is a traditional management in most fire-affected areas. In some cases, the way of doing it, using heavy machinery, and the vulnerability of soils to erosion and degradation make this management potentially very agresive to soil, and therefore to the ecosystem. Very little research has been done to study how this treatment could affect soil health. In this research we show 2 years of monitoring of some soil properties in an area affected by a forest fire, where some months later this treatment was applied. The study area is located in 'Sierra de Mariola Natural Park' in Alcoi, Alicante (E Spain). A big forest fire (>500 has) occurred in July 2012. The forest is composed mainly of Pinus halepensis trees with an understory of typical Mediterranean shrubs species such as Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Brachypodium retusum, etc. Soil is classified as a Typic Xerorthent (Soil Survey Staff, 2014) developed over marls. In February 2013, salvage logging (SL) treatment consisting in a complete extraction of the burned wood using heavy machinery was applied in a part of the affected forest. Plots for monitoring this effect were installed in this area and in a similar nearby area where no treatment was done, and then used as control (C) for comparison. Soil samplings were done immediately after treatment and every 6 months. Some soil properties were analysed, including soil organic matter (SOM) content, basal soil respiration (BSR), microbial biomass carbon (MBC), bulk density (BD), soil water repellency (SWR), aggregate stability (AS), field capacity, nitrogen, etc. After two years of

  3. Biogenic NO emissions from forest and pasture soils: Relating laboratory studies to field measurements

    NASA Astrophysics Data System (ADS)

    van Dijk, S. M.; Gut, A.; Kirkman, G. A.; Gomes, B. M.; Meixner, F. X.; Andreae, M. O.

    2002-10-01

    During September and October 1999, dynamic chamber measurements were carried out to determine nitric oxide (NO) fluxes from a primary forest soil and an old pasture in the Brazilian Amazon basin as part of the project "European Studies of Trace Gases and Atmospheric Chemistry as a Contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia" (LBA-EUSTACH). In addition, soil samples were collected from these two sites, and laboratory experiments were conducted to determine the NO production and consumption rate constants as functions of soil temperature and soil moisture. These laboratory results were converted into NO fluxes using a simple algorithm, which required additional information on the gas diffusion in soil, the soil bulk density, and the field conditions (soil temperature and soil moisture). Over the entire measurement period, the calculated and measured NO fluxes agreed well both for the forest (6.9 ± 2.9 and 5.0 ± 4.6 ng m-2 s-1, respectively) and for the pasture (0.67 ± 0.09 and 0.65 ± 0.37 ng m-2 s-1, respectively). Forest to pasture conversion decreased NO production and gas diffusion and resulted in smaller NO fluxes from pasture than forest soil.

  4. Recovery of Soil Microbial Community Structure in a Wildfire Impacted Forest Soil

    NASA Astrophysics Data System (ADS)

    Tate, Robert, III; Mikita, Robyn

    2010-05-01

    Wildfires are common disturbances that will increase in frequency and intensity as a result of conditions associated with the changing climate. In turn, forest fires exacerbate climate conditions by increasing carbon and atmospheric aerosols, and changing the surface albedo. Fires have significant economic, environmental, and ecological repercussions; however, we have a limited understanding on the effect of severe wildfires on the composition, diversity, and function of belowground microorganisms. The objective of this research was to examine the shift of the forest soil microbial community as a result of a severe wildfire in the New Jersey Pinelands. Over the span of two years following the fire, soil samples from the organic and mineral layers of the severely burned sites were collected six times. Samples were also collected twice from an unburned control site. It was hypothesized that soil microbial communities from severely burned samples collected shortly after the fire would be significantly different from (1) the unburned samples that serve as controls and (2) the severely burned samples collected more than a year after the fire. Microbial community composition was analyzed by principal component analysis and multivariate analysis of variance of molecular fingerprint data from denaturing gradient gel electrophoresis of bacterial and archaeal-specific amplicons. Bacterial community composition was significantly different among all the organic and mineral layer samples collected 2, 5, 13, and 17 months following the fire. This indicated a shift in the bacterial communities with time following the fire. Common phylotypes from the burned organic layer samples collected 2 months after the fire related closely to members of the phyla Cyanobacteria and Acidobacteria, whereas those from later samples (5, 13, and 17 months following the fire) were closely related to members of the genus Mycobacteria. Canonical correlation analysis was used to determine connections

  5. Cohnella collisoli sp. nov., isolated from lava forest soil.

    PubMed

    Lee, Keun Chul; Kim, Kwang Kyu; Kim, Jong-Shik; Kim, Dae-Shin; Ko, Suk-Hyung; Yang, Seung-Hoon; Lee, Jung-Sook

    2015-09-01

    A novel bacterial strain, NKM-5(T), was isolated from soil of a lava forest in Nokkome Oreum, Jeju, Republic of Korea. Cells of strain NKM-5(T) were Gram-stain-positive, motile, endospore-forming, rod-shaped and oxidase- and catalase-positive. Strain NKM-5(T) contained anteiso-C15 : 0 and iso-C16 : 0 as the major fatty acids; menaquinone-7 (MK-7) as the predominant isoprenoid quinone; diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, lysyl-phosphatidylglycerol, an unidentified phospholipid and three unidentified aminophospholipids as the polar lipids; and meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The DNA G+C content was 48.3 mol%. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that strain NKM-5(T) was most closely related to Cohnella lupini RLAHU4B(T) (96.9% sequence similarity) and fell into a clade in the genus Cohnella. On the basis of phylogenetic, chemotaxonomic and phenotypic data, strain NKM-5(T) represents a novel species of the genus Cohnella, for which the name Cohnella collisoli sp. nov. is proposed. The type strain is NKM-5(T) ( = KCTC 33634(T) = CECT 8805(T)). PMID:26296691

  6. Micromonospora humi sp. nov., isolated from peat swamp forest soil.

    PubMed

    Songsumanus, Apakorn; Tanasupawat, Somboon; Thawai, Chitti; Suwanborirux, Khanit; Kudo, Takuji

    2011-05-01

    A novel actinomycete, strain P0402(T), was isolated from peat swamp forest soil collected in Thailand. Its taxonomic position was determined by using a polyphasic taxonomic approach. The chemotaxonomic characteristics of this strain matched those of the genus Micromonospora, i.e. the presence of meso-diaminopimelic acid and N-glycolyl muramic acid in the peptidoglycan, whole-cell sugar pattern D, phospholipid type II, and cellular fatty acid type 3b. Phylogenetic analysis based on 16S rRNA gene sequences revealed a close relationship between strain P0402(T) and Micromonospora coxensis JCM 13248(T) (99.0 % similarity), Micromonospora eburnea JCM 12345(T) (99.0 %), Micromonospora marina JCM 12870(T) (98.9 %), Micromonospora halophytica JCM 3125(T) (98.7 %), Micromonospora chalcea JCM 3031(T) (98.7 %), Micromonospora purpureochromogenes JCM 3156(T) (98.6 %) and Micromonospora aurantiaca JCM 10878(T) (98.5 %). It could be clearly distinguished from these type strains based on low levels of DNA-DNA relatedness and phenotypic differences. On the basis of the data presented, strain P0402(T) is suggested to represent a novel species of the genus Micromonospora, for which the name Micromonospora humi sp. nov. is proposed. The type strain is P0402(T) ( = JCM 15292(T)  = PCU 315(T)  = TISTR 1883(T)). PMID:20562246

  7. Stability of Trifluoromethane in Forest Soils and Methanotrophic Cultures

    NASA Technical Reports Server (NTRS)

    King, Gary M.

    1997-01-01

    Trifluoromethane (TFM) has been reported as an endproduct of trifluoroacetate degradation under oxic conditions. Although other halomethanes, such as chloroform, methyl bromide, and methyl fluoride, inhibit methane oxidation or are degraded by methanotrophs, the fate of TFM is unknown. TFM had no affect on atmospheric methane consumption when added to forest soils at either 10 ppm or 10,000 ppm. No degradation of TFM was observed at either concentration for incubations of 6 days. Cultures of Methylobacter albus BG8 and Methylosinus trichosporium OB3b grown With and without added copper were also used to assay TFM degradation at 10 10000 ppm levels. TFM did not inhibit methane oxidation under any growth conditions, including those inducing expression of soluble methane monooxygenase, nor was it degraded at measurable rates. In contrast, parallel assays showed that both methyl fluoride and chloroform inhibited methane oxidation in M. trichosporium OB3b. Our results suggest that TFM may be relatively inert with respect to methanotrophic degradition. Although TFM has a negligible ozone depletion potential, it absorbs infrared radiation and has a relatively long atmospheric residence time. Thus, accumulation of TFM in the atmosphere as a consequence of the decomposition of hydrochlorofluorocarbons may have significant unpredicted climate impacts.

  8. Actinospica durhamensis sp. nov., isolated from a spruce forest soil.

    PubMed

    Golinska, Patrycja; Zucchi, Tiago Domingues; Silva, Leonardo; Dahm, Hanna; Goodfellow, Michael

    2015-08-01

    Seven acidophilic actinobacteria isolated from humus and mineral layers of a spruce forest soil were examined using a polyphasic approach. Chemotaxonomic properties of the isolates were found to be consistent with their classification in the genus Actinospica. The strains formed a distinct phyletic line in the Actinospica 16S rRNA gene tree being most closely related to Actinospica robiniae DSM 44927(T) (98.7-99.3 % similarity). DNA:DNA relatedness between isolate CSCA57(T) and the type strain of A. robiniae was found to be low at 40.8 (±6.6) %. The isolates were shown to have many phenotypic properties in common and were distinguished readily from the type strains of Actinospica acidiphila and A. robiniae using a range of phenotypic features. On the basis of these data the seven isolates were considered to represent a new species for which the name Actinospica durhamensis sp. nov. is proposed. The type strain of the species is CSCA 57(T) (=DSM 46820(T) = NCIMB 14953(T)). PMID:26026797

  9. Catenulispora fulva sp. nov., isolated from forest soil.

    PubMed

    Lee, Hyo-Jin; Whang, Kyung-Sook

    2016-01-01

    An actinomycete strain, designated SA-246T, was isolated from a forest soil sample collected from Chungnam, South Korea. Applying a polyphasic approach, the isolate was identified as a member of the genus Catenulispora using morphological and chemotaxonomic characteristics, including the presence of ll-diaminopimelic acid, glutamic acid, alanine and glycine in the peptidoglycan. Whole-cell hydrolysates contained predominantly rhamnose, mannose, ribose, arabinose, galactose and glucose. The major menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8). 16S rRNA gene sequence analysis revealed that strain SA-246T belongs to the genus Catenulispora, showing the highest sequence similarity to Catenulispora yoronensis TT N02-20T (98.7 % 16S rRNA gene sequence similarity), Catenulispora subtropica TT 99-48T (98.2 %), Catenulispora graminis BR-34T (97.4 %), Catenulispora rubra Aac-30T (97.4 %) and Catenulispora acidiphila ID139908T (97.3 %). On the basis of polyphasic analysis from this study, strain SA-246T represents a novel species of the genus Catenulispora, for which the name Catenulispora fulva sp. nov. is proposed. The type strain is SA-246T ( = KACC 17878T = NBRC 110074T). PMID:26507964

  10. Paenibacillus terreus sp. nov., isolated from forest soil.

    PubMed

    Huang, Zhi; Dai, Wenjuan; Zhou, Zhijun; Wang, Guoxiang; Lin, Guoqing; Yan, Xixue; Zhao, Fei

    2016-01-01

    A Gram-stain-positive, rod-shaped, endospore-forming, motile bacterium, designated D33T, was isolated from a forest soil sample. The strain grew optimally at 30-37 °C, pH 8.0 and with 1 % (w/v) NaCl. The 16S rRNA gene sequence of the isolate showed similarities lower than 97 % with respect to species of the genus Paenibacillus. Strain D33T contained meso-diaminopimelic acid in the cell-wall peptidoglycan, and ribose and lower amounts of glucose and galactose as the whole-cell sugars. The major cellular fatty acid was anteiso-C15 : 0, and menaquinone-7 (MK-7) was the only respiratory quinone. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, two glycolipids and an unknown lipid. The DNA G+C content was 51.1 mol%. The low DNA-DNA relatedness values between strain D33T and recognized species of the genus Paenibacillus, together with many phenotypic properties supported the classification of strain D33T as representative of a novel species of the genus Paenibacillus, for which the name Paenibacillus terreus sp. nov. is proposed. The type strain is D33T ( = KACC 18491T = DSM 100035T = CCTCC AB 2015273T). PMID:26493172

  11. Forest Cover Change and Soil Erosion in Toledo's Rio Grande Watershed

    NASA Astrophysics Data System (ADS)

    Chicas, S.; Omine, K.

    2015-04-01

    Toledo, the southernmost district, is the hub of Belize's Mayan population, descendants of the ancient Mayan civilization. The Toledo District is primarily inhibited by Kekchi and Mopan Mayans whose subsistence needs are met by the Milpa slash-and-burn agricultural system and the extraction of forest resources. The poverty assessment in the country indicates that Toledo is the district with the highest percentage of household an individual indigence of 37.5 % and 49.7 % respectively. Forest cover change in the area can be attributed to rapid population growth among the Maya, together with increase in immigration from neighboring countries, logging, oil exploration and improvement and construction of roads. The forest cover change analysis show that from 2001 to 2011 there was a decrease of Lowland broad-leaved wet forest of 7.53 km sq, Shrubland of 4.66 km sq, and Wetland of 0.08 km sq. Forest cover change has resulted in soil erosion which is causing the deterioration of soils. The land cover types that are contributing the most to total erosion in the Rio Grande watershed are no-forest, lowland broad-leaved wet forest and submontane broad-leaved wet forest. In this study the Revised Universal Soil Loss Equation (RUSLE) was employed in a GIS platform to quantify and assess forest cover change and soil erosion. Soil erosion vulnerability maps in Toledo's Rio Grande watershed were also created. This study provides scientifically sound information in order to understand and respond effectively to the impacts of soil erosion in the study site.

  12. Drivers of atmospheric methane uptake by montane forest soils in the southern Peruvian Andes

    NASA Astrophysics Data System (ADS)

    Jones, Sam P.; Diem, Torsten; Huaraca Quispe, Lidia P.; Cahuana, Adan J.; Reay, Dave S.; Meir, Patrick; Arn Teh, Yit

    2016-07-01

    The soils of tropical montane forests can act as sources or sinks of atmospheric methane (CH4). Understanding this activity is important in regional atmospheric CH4 budgets given that these ecosystems account for substantial portions of the landscape in mountainous areas like the Andes. We investigated the drivers of net CH4 fluxes from premontane, lower and upper montane forests, experiencing a seasonal climate, in south-eastern Peru. Between February 2011 and June 2013, these soils all functioned as net sinks for atmospheric CH4. Mean (standard error) net CH4 fluxes for the dry and wet season were -1.6 (0.1) and -1.1 (0.1) mg CH4-C m-2 d-1 in the upper montane forest, -1.1 (0.1) and -1.0 (0.1) mg CH4-C m-2 d-1 in the lower montane forest, and -0.2 (0.1) and -0.1 (0.1) mg CH4-C m-2 d-1 in the premontane forest. Seasonality in CH4 exchange varied among forest types with increased dry season CH4 uptake only apparent in the upper montane forest. Variation across these forests was best explained by available nitrate and water-filled pore space indicating that nitrate inhibition of oxidation or diffusional constraints imposed by changes in water-filled pore space on methanotrophic communities may represent important controls on soil-atmosphere CH4 exchange. Net CH4 flux was inversely related to elevation; a pattern that differs to that observed in Ecuador, the only other extant study site of soil-atmosphere CH4 exchange in the tropical Andes. This may result from differences in rainfall patterns between the regions, suggesting that attention should be paid to the role of rainfall and soil moisture dynamics in modulating CH4 uptake by the organic-rich soils typical of high-elevation tropical forests.

  13. [Vertical Distribution Characteristics of Typical Forest Soil Organic Nitrogen in Dawei Mountain].

    PubMed

    Ding, Xian-qing; Ma, Hui-jing; Zhu, Xiao-long; Chen, Shan; Hou, Hong-bo; Peng, Pei-qin

    2015-10-01

    To clarify altitudinal gradient of subtropical forest soil total nitrogen and organic nitrogen, soil samples were collected per 10 cm on soil profile (0-100 cm) in Dawei Mountain, researched the variation of soil organic nitrogen and correlation with soil physical and chemical properties. The results showed that: (1) Total nitrogen, acid hydrolysable organic nitrogen and soluble organic nitrogen decreased with the increase of depth, content of each component in mountain granite yellow-brown soils was much higher affected by altitude; (2) The average percentage of soil organic nitrogen to total nitrogen was 97.39% ± 1.17%, and soil acid hydrolysable organic nitrogen was 64.38% ± 10.68%, each component decreased with the increase of soil depth; (3) Soil soluble organic nitrogen content was 9.92- 23.45 mg x kg(-1), free amino acids (1.62 - 12.02 mg x kg(-1)) accounted for about 27.36% ± 9.95% of soluble organic nitrogen; (4) Soil acid hydrolysable organic nitrogen and soluble organic nitrogen were significantly positively correlated with total nitrogen, total soluble nitrogen and inorganic nitrogen (P < 0.05), were highly significantly correlated with soil bulk density, organic carbon, and total phosphorus (P < 0.01). Organic nitrogen was the main body of soil nitrogen in typical subtropical forest, each component showed a downward trend increase with soil depth affected by altitude and soil physical and chemical properties. There was a close conversion relationship between soil organic nitrogen and other nitrogen forms, the characteristics of soil organic nitrogen will have profound impact on nitrogen cycling of forest ecological system. PMID:26841616

  14. Comparison between soil and biomass carbon in adjacent hardwood and red pine forests

    SciTech Connect

    Perala, D.A.; Rollinger, J.L.; Wilson, D.M.

    1995-06-01

    The distribution of carbon in soil and biomass was studied across Minnesota, Wisconsin, and Michigan, USA, in 40 pole-sized red pine (Pinus resinosa Ait.) plantations paired with adjacent hardwood stands. Pine and hardwood stands shared a common boundary and soil. Hardwood stands were mixed species, naturally regenerated second growth following logging. Carbon in total, standing crop averaged the same in both hardwood and red pine forest types, although the hardwoods averaged 14 years older than red pine. Coarse woody debris, shrubs, and herbs contained little carbon. Only the forest floor carbon pool was significantly different between forest types. Forest floor had a greater mass beneath red pine than hardwoods. There was no difference in total ecosystem carbon between red pine and hardwood stands. Total mineral soil aggregated across the depth profile contained the same total amount of carbon in both pine and hardwood stands; however, the carbon was found in different vertical patterns. Amounts of carbon in the upper levels of soil (0--4 cm) were higher under hardwoods, and amounts were higher under red pine at the 8--16 cm and 16--32 cm soil depths. Where July air temperatures were relatively cool, red pine stored carbon more efficiently both in the forest floor and deep in the soil. Red pine also sequestered more carbon in mineral soil with increasing April--September precipitation.

  15. Climate controls on forest soil C isotope ratios in the southern Appalachian Mountains

    SciTech Connect

    Garten Jr, Charles T; Cooper, Lee W; Post, Wilfred M; Hanson, Paul J

    2000-04-01

    A large portion of terrestrial carbon (C) resides in soil organic carbon (SOC). The dynamics of this large reservoir depend on many factors, including climate. Measurements of {sup 13}C:{sup 12}C ratios, C concentrations, and C:N ratios at six forest sites in the Southern Appalachian Mountains (USA) were used to explore several hypotheses concerning the relative importance of factors that control soil organic matter (SOM) decomposition and SOC turnover. Mean {delta}{sup 13}C values increased with soil depth and decreasing C concentrations along a continuum from fresh litter inputs to more decomposed soil constituents. Data from the six forest sites, in combination with data from a literature review, indicate that the extent of change in {delta}{sup 13}C values from forest litter inputs to mineral soil (20 cm deep) is significantly associated with mean annual temperature. The findings support a conceptual model of vertical changes in forest soil {delta}{sup 13}C values, C concentrations, and C:N ratios that are interrelated through climate controls on decomposition. We hypothesize that, if other environmental factors (like soil moisture) are not limiting, then temperature and litter quality indirectly control the extent of isotopic fractionation during SOM decomposition in temperate forest ecosystems.

  16. Soil survey of Solid Waste Storage Area 6

    SciTech Connect

    Lietzke, D.A.; Lee, S.Y.

    1986-06-01

    An intensive soil survey was made of Solid Waste Storage Area (SWSA) 6 (Oak Ridge National Laboratory) at a scale of 1:1200. The amount of chemical weathering, the thickness of upland soils, and the depth to unoxidized rock are dependent on slope gradient, water-flow pathways, degree of rock fracturing, and the extent of soil and rock erosion by late Pleistocene and Holocene geomorphic processes. Foot-slope landforms have generally concave slope shapes where sediment accumulates. Colluvium stratigraphy exhibits at least one lithologic discontinuity, but there may be two discontinuities preserved in some thicker colluvia. One or more paleosols, either complete or partially truncated, are preserved in these concave landforms. Alluvial soils were not examined in detail but were separated from colluvial soils because of their wetness. A small area of ancient alluvium was located on a stable upland summit that formed the highest elevation in SWSA-6. On the nearly level summit, a thin loess cap was preserved on the older alluvial soil. Upland and colluvial soils are all highly leached and strongly acid even though they are formed from a calcareous parent rock. The highly fractured rock, being relatively permeable, has been leached free of carbonates in the upper levels so that there is a wide pH gradient from the surface downward. Most of the soils were classified as Ultisols, with minimal areas of Alfisols, Inceptisols, and Entisols. Based on the soil survey, representative landforms and soils will be selected to study physical, chemical, and mineralogical properties of the soil and weathered rock. Those properties will be used to predict both the amount and duration of leachate filtration and purification in downward migration to the water table or lateral migration through colluvial and alluvial soils to ground-water seeps.

  17. Interactive Effects of Nitrogen and Phosphorus on Soil Microbial Communities in a Tropical Forest

    PubMed Central

    Liu, Lei; Zhang, Tao; Gilliam, Frank S.; Gundersen, Per; Zhang, Wei; Chen, Hao; Mo, Jiangming

    2013-01-01

    Elevated nitrogen (N) deposition in humid tropical regions may exacerbate phosphorus (P) deficiency in forests on highly weathered soils. However, it is not clear how P availability affects soil microbes and soil carbon (C), or how P processes interact with N deposition in tropical forests. We examined the effects of N and P additions on soil microbes and soil C pools in a N-saturated old-growth tropical forest in southern China to test the hypotheses that (1) N and P addition will have opposing effects on soil microbial biomass and activity, (2) N and P addition will alter the composition of the microbial community, (3) the addition of N and P will have interactive effects on soil microbes and (4) addition-mediated changes in microbial communities would feed back on soil C pools. Phospholipid fatty acid (PLFA) analysis was used to quantify the soil microbial community following four treatments: Control, N addition (15 g N m−2 yr−1), P addition (15 g P m−2 yr−1), and N&P addition (15 g N m−2 yr−1 plus 15 g P m−2 yr−1). These were applied from 2007 to 2011. Whereas additions of P increased soil microbial biomass, additions of N reduced soil microbial biomass. These effects, however, were transient, disappearing over longer periods. Moreover, N additions significantly increased relative abundance of fungal PLFAs and P additions significantly increased relative abundance of arbuscular mycorrhizal (AM) fungi PLFAs. Nitrogen addition had a negative effect on light fraction C, but no effect on heavy fraction C and total soil C. In contrast, P addition significantly decreased both light fraction C and total soil C. However, there were no interactions between N addition and P addition on soil microbes. Our results suggest that these nutrients are not co-limiting, and that P rather than N is limiting in this tropical forest. PMID:23593427

  18. Surficial gains and subsoil losses of soil carbon and nitrogen during secondary forest development.

    PubMed

    Mobley, Megan L; Lajtha, Kate; Kramer, Marc G; Bacon, Allan R; Heine, Paul R; Richter, Daniel Deb

    2015-02-01

    Reforestation of formerly cultivated land is widely understood to accumulate above- and belowground detrital organic matter pools, including soil organic matter. However, during 40 years of study of reforestation in the subtropical southeastern USA, repeated observations of above- and belowground carbon documented that significant gains in soil organic matter (SOM) in surface soils (0-7.5 cm) were offset by significant SOM losses in subsoils (35-60 cm). Here, we extended the observation period in this long-term experiment by an additional decade, and used soil fractionation and stable isotopes and radioisotopes to explore changes in soil organic carbon and soil nitrogen that accompanied nearly 50 years of loblolly pine secondary forest development. We observed that accumulations of mineral soil C and N from 0 to 7.5 cm were almost entirely due to accumulations of light-fraction SOM. Meanwhile, losses of soil C and N from mineral soils at 35 to 60 cm were from SOM associated with silt and clay-sized particles. Isotopic signatures showed relatively large accumulations of forest-derived carbon in surface soils, and little to no accumulation of forest-derived carbon in subsoils. We argue that the land use change from old field to secondary forest drove biogeochemical and hydrological changes throughout the soil profile that enhanced microbial activity and SOM decomposition in subsoils. However, when the pine stands aged and began to transition to mixed pines and hardwoods, demands on soil organic matter for nutrients to support aboveground growth eased due to pine mortality, and subsoil organic matter levels stabilized. This study emphasizes the importance of long-term experiments and deep measurements when characterizing soil C and N responses to land use change and the remarkable paucity of such long-term soil data deeper than 30 cm. PMID:25155991

  19. Livermore Big Trees Park Soil Survey

    SciTech Connect

    McConachie, W.A.; Failor, R.A.

    1995-01-01

    Lawrence Livermore National Laboratory (LLNL) will sample and analyze soil in the Big Trees Park area in Livermore, California, to determine if the initial level of plutonium (Pu) in a soil sample taken by the U.S. Environmental Protection Agency (EPA) in September 1993 can be confirmed. Nineteen samples will be collected and analyzed: 4 in the area where the initial EPA sample was taken, 2 in the nearby Arroyo Seco, 12 in scattered uncovered soil areas in the park and nearby school, and 1 from the sandbox of a nearby apartment complex. Two quality control (QC) samples (field duplicates of the preceding samples) win also be collected and analyzed. This document briefly describes the purpose behind the sampling, the sampling rationale, and the methodology.

  20. P Limitation and Microbial Biogeochemistry in Acidic Forest Soils of the Northeastern United States

    NASA Astrophysics Data System (ADS)

    Smemo, K. A.; Deforest, J. L.; Burke, D. J.; Elliot, H. L.; Kluber, L. A.; Carrino-Kyker, S. R.

    2010-12-01

    In forest ecosystems with acidic soils, such as many hardwood forests of the Northeastern United States, net primary productivity should be limited by phosphorus (P) because P is biologically less available at pH < 5 and nitrogen (N) has become more abundant in response to anthropogenic inputs. However, previous studies have failed to demonstrate widespread P limitation in temperate forests that have naturally acidic soil or are exposed to chronic acid deposition; such findings are contrary to biogeochemical expectations. We hypothesize that many eastern forests possess an underlying P limitation not realized at the ecosystem level. Instead, shifts in the composition, structure and function of soil microbial communities compensate by acquiring more P from organic sources and P limitation is therefore not manifested at the aboveground (plant) level. To test this hypothesis, we manipulated soil pH and P availability in 72 20 x 40 m mature hardwood forest plots across northeastern (glaciated) and southeastern (unglaciated) Ohio beginning in late summer 2009. Ten months after treatment initiation, soil pH has increased from 4.5 to 5.5 and soil P has increased from 3 to ~25 mg P/kg soil on glaciated soils and from 0.5 to ~5 mg P/kg soil on unglaciated soils. To quantify treatment responses, we measured the activity of soil extracellular enzymes associated with liberation of P, N, and C from organic matter, as well as pools of N and N cycling processes. We saw no significant effects of our treatments on pools of available ammonium or nitrate, nor did we see effects on net N mineralization and net nitrification rates. However, glaciated soils had significantly greater nitrate pools and higher N cycling rates than older unglaciated soils. Nitrogen and C cycling enzymes in treatment plots were not significantly different than control plots, but N-acetylglucosaminidase activity (N acquisition) was significantly greater in the unglaciated soils and β-glucosidase and

  1. Transfer of radio-cesium from forest soil to woodchips using fungal activities

    NASA Astrophysics Data System (ADS)

    Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

    2014-05-01

    Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be

  2. Ash after forest fires. Effects on soil hydrology and erosion

    NASA Astrophysics Data System (ADS)

    Bodí, Merche B.

    2013-04-01

    from certain Eucaliptus and Pinus), or if clog soil pores (depending also on the soil type). If ash is wettable, it can store even 80% of its volume and then it will delay and reduce overland flow proportionally to the thickness of the ash layer. Once ash gets saturated, the flow tends to adjust to an infiltration rate similar to the soil itself, or sometimes higher due to the protection of ash that can reduce soil water repellency and soil sealing (Bodí et al. 2011, 2012). Still, many other aspects on ash remain unknown and ash present us more questions like, what it is its role on the carbon cycle? what is the extent of the ahs effects at basin scale? what is the fate of ash and how long it remains in the ecosystem? are there specific effects of ash depending on the ecosystem and so the type of ash? Acknowledgements This work was supported financially by a research fellowship (AP2007-04602) from the Spanish Ministry of Science and Innovation (M.B. Bodí) and the projects PT2009-0073 and CGL2010-21670-C02-01. References Bodí, M.B., Mataix-Solera, J., Doerr, S.H., Cerdà, A., 2011, The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma 160, 599-607. Bodí, M.B., Doerr, S.H., Cerdà, A., Mataix-Solera, J., 2012, Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soil. Geoderma 191, 14-23 Cerdà, A., 1998, Changes in overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes 12, 1031-1042. Cerdà, A., Doerr, S.H., 2008, The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena 74, 256-263. Woods, S.W., Balfour, V., 2008, The effect of ash on runoff and erosion after a forest wildfire, Montana, U.S.A. International Journal of Wildland Fire 17, 535-548.

  3. Responses of soil respiration and its temperature/moisture sensitivity to precipitation in three subtropical forests in southern China

    NASA Astrophysics Data System (ADS)

    Jiang, H.; Deng, Q.; Zhou, G.; Hui, D.; Zhang, D.; Liu, S.; Chu, G.; Li, J.

    2013-06-01

    Both long-term observation data and model simulations suggest an increasing chance of serious drought in the dry season and extreme flood in the wet season in southern China, yet little is known about how changes in precipitation pattern will affect soil respiration in the region. We conducted a field experiment to study the responses of soil respiration to precipitation manipulations - precipitation exclusion to mimic drought, double precipitation to simulate flood, and ambient precipitation as control (abbr. EP, DP and AP, respectively) - in three subtropical forests in southern China. The three forest sites include Masson pine forest (PF), coniferous and broad-leaved mixed forest (MF) and monsoon evergreen broad-leaved forest (BF). Our observations showed that altered precipitation strongly influenced soil respiration, not only through the well-known direct effects of soil moisture on plant and microbial activities, but also by modification of both moisture and temperature sensitivity of soil respiration. In the dry season, soil respiration and its temperature sensitivity, as well as fine root and soil microbial biomass, showed rising trends with precipitation increases in the three forest sites. Contrarily, the moisture sensitivity of soil respiration decreased with precipitation increases. In the wet season, different treatments showed different effects in three forest sites. The EP treatment decreased fine root biomass, soil microbial biomass, soil respiration and its temperature sensitivity, but enhanced soil moisture sensitivity in all three forest sites. The DP treatment significantly increased soil respiration, fine root and soil microbial biomass in the PF only, and no significant change was found for the soil temperature sensitivity. However, the DP treatment in the MF and BF reduced soil temperature sensitivity significantly in the wet season. Our results indicated that soil respiration would decrease in the three subtropical forests if soil moisture

  4. The effect of nitrogen fertilization on soil surface CO2 fluxes in Siberian forest soils

    NASA Astrophysics Data System (ADS)

    Matvienko, Anastasia; Menyailo, Oleg

    2015-04-01

    Human activities, production of nitrogen fertilizers have altered the global nitrogen cycle greater than the carbon cycle. The purpose of our study was to investigate the effect of nitrogen application on the CO2 flux under two tree species - Siberian larch and Scots pine. To estimate nitrogen effect on heterotrophic and autotrophic components of soil respiration the three-year experiment with deep and shallow collars was carried out. Collars were installed in May of 2010. Nitrogen was applied in June of 2010 in the form of ammonium nitrate (dry) at the rate of 50 kg N/ha on the four replicated plots under both tree species. The emission of CO2 was measured every 2 weeks from May to October over three years with LI-8100A CO2 analyzer. Nitrogen application positively affected soil surface CO2 flux under both tree species. The effect of N was even significant for annual CO2 production. Under Scots pine, the N fertilization increased annual CO2 production during the first and second year of measurements, under larch only for the first year. For the third year the effect of N has disappeared under both tree species. The total losses of soil carbon due to N application were 600-650 kg C/ha under Siberian larch and three times higher (1800-2000 kg C/ha) under Scots pine. Different collar types revealed that the effect was mostly due to increased activity of heterotrophs and subsequent laboratory incubations proved that this activity was accelerated by N mostly in the litter layers. Overall, our results suggest that in N unpolluted Siberia, the application of N leads to soil C losses, mainly due to accelerated decomposition of forest floor. The losses of soil C might exceed N-driven C sequestration in tree biomass, negating thus positive effect of N addition on net C sequestration.

  5. Nitrogen saturation, soil acidification, and ecological effects in a subtropical pine forest on acid soil in southwest China

    NASA Astrophysics Data System (ADS)

    Huang, Yongmei; Kang, Ronghua; Mulder, Jan; Zhang, Ting; Duan, Lei

    2015-11-01

    Elevated anthropogenic nitrogen (N) deposition has caused nitrate (NO3-) leaching, an indication of N saturation, in several temperate and boreal forests across the Northern Hemisphere. So far, the occurrence of N saturation in subtropical forests and its effects on the chemistry of the typically highly weathered soils, forest growth, and biodiversity have received little attention. Here we investigated N saturation and the effects of chronically high N inputs on soil and vegetation in a typical, subtropical Masson pine (Pinus massoniana) forest at Tieshanping, southwest China. Seven years of N flux data obtained in ambient conditions and in response to field manipulation, including a doubling of N input either as ammonium nitrate (NH4NO3) or as sodium nitrate (NaNO3) solution, resulted in a unique set of N balance data. Our data showed extreme N saturation with near-quantitative leaching of NO3-, by far the dominant form of dissolved inorganic N in soil water. Even after 7 years, NH4+, added as NH4NO3, was nearly fully converted to NO3-, thus giving rise to a major acid input into the soil. Despite the large acid input, the decrease in soil pH was insignificant, due to pH buffering caused by Al3+ mobilization and enhanced SO42- adsorption. In response to the NH4NO3-induced increase in soil acidification and N availability, ground vegetation showed significant reduction of abundance and diversity, while Masson pine growth further declined. By contrast, addition of NaNO3 did not cause soil acidification. The comparison of NH4NO3 treatment and NaNO3 treatment indicated that pine growth decline was mainly attributed to acidification-induced nutrient imbalance, while the loss in abundance of major ground species was the combining effect of N saturation and acidification. Therefore, N emission control is of primary importance to curb further acidification and eutrophication of forest soils in much of subtropical south China.

  6. Modeling dissolved organic carbon in temperate forest soils: TRIPLEX-DOC model development and validation

    NASA Astrophysics Data System (ADS)

    Wu, H.; Peng, C.; Moore, T. R.; Hua, D.; Li, C.; Zhu, Q.; Peichl, M.; Arain, M. A.; Guo, Z.

    2014-05-01

    Even though dissolved organic carbon (DOC) is the most active carbon (C) cycling in soil organic carbon (SOC) pools, it receives little attention from the global C budget. DOC fluxes are critical to aquatic ecosystem inputs and contribute to the C balance of terrestrial ecosystems, but few ecosystem models have attempted to integrate DOC dynamics into terrestrial C cycling. This study introduces a new process-based model, TRIPLEX-DOC, that is capable of estimating DOC dynamics in forest soils by incorporating both ecological drivers and biogeochemical processes. TRIPLEX-DOC was developed from Forest-DNDC, a biogeochemical model simulating C and nitrogen (N) dynamics, coupled with a new DOC process module that predicts metabolic transformations, sorption/desorption, and DOC leaching in forest soils. The model was validated against field observations of DOC concentrations and fluxes at white pine forest stands located in southern Ontario, Canada. The model was able to simulate seasonal dynamics of DOC concentrations and the magnitudes observed within different soil layers, as well as DOC leaching in the age sequence of these forests. Additionally, TRIPLEX-DOC estimated the effect of forest harvesting on DOC leaching, with a significant increase following harvesting, illustrating that land use change is of critical importance in regulating DOC leaching in temperate forests as an important source of C input to aquatic ecosystems.

  7. Use of LANDSAT imagery for soil survey

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Filho, M. V.; Higa, N. T.; Celsodecarvalho, V.

    1977-01-01

    The author has identified the following significant results. The MSS channels 6 and 7 were considered the best to study the relative tonality of different spectral responses of soils, while channels 5 and 7 were best for natural vegetation, drainage patterns, and land use. Frequency ratio was the recommended index for use when analyzing a drainage pattern quantitatively.

  8. Understanding the prairie-forest transitional zone in northern Minnesota through variations in soil chemistry

    NASA Astrophysics Data System (ADS)

    Kasmerchak, C. S.; Mason, J. A.

    2015-12-01

    Boundaries between soil types are not discrete, but instead there are transitional zones that exhibit characteristics of soil types that they border. The prairie-forest transitional zone is seen throughout North America and Eurasia. Prairie soils (Mollisols) and deciduous forest soils (Alfisols) demonstrate interesting contrasts in morphology. Understanding variations in chemical properties is key to understanding nutrient cycling and retention, ecosystem development, and furthering the field of soil geography. Research sites are located in northern Minnesota's eastern forest, western prairie, and the transitional forested zone between. Evidence of clay translocation is a key indicator of Alfisol development. The double layer theory suggests chemical factors allowing clays to be dispersed/flocculated are ionic strength of the solution, relative abundance of Na+ and di- or trivalent cations, and pH (Sposito, 1984; van Olphen, 1977). In initial stages of soil formation exchangeable bases (Na+, K+, Ca++, and Mg++) occupy 100% of clay exchange sites, but as soil develops are these replaced by acidity ions (H+ and Al3+) and base saturation decreases. The relationship between exchangeable cations and clay dispersion is understood in lower horizons where Ca++ and Mg++ are abundant, and clay is flocculated, but this is not well understood in upper horizons. However it is suggested that clay dispersion can occur in upper horizons of pH values between 7 and 5 (van Breeman and Buurman, 2002). CEC values are expected to be much higher in soils where clay is flocculated and base ion concentration is high. Preliminary analyses supports that differences in these chemical factors are key indicators of varying rates of soil development, and explain geographic distribution of soils in this region. Through further lab work and data analysis, the relative importance of these chemical properties will come to light and the drivers prairie-forest soil transition will be better understood.

  9. Land use change alters functional gene diversity, composition and abundance in Amazon forest soil microbial communities.

    PubMed

    Paula, Fabiana S; Rodrigues, Jorge L M; Zhou, Jizhong; Wu, Liyou; Mueller, Rebecca C; Mirza, Babur S; Bohannan, Brendan J M; Nüsslein, Klaus; Deng, Ye; Tiedje, James M; Pellizari, Vivian H

    2014-06-01

    Land use change in the Amazon rainforest alters the taxonomic structure of soil microbial communities, but whether it alters their functional gene composition is unknown. We used the highly parallel microarray technology GeoChip 4.0, which contains 83,992 probes specific for genes linked nutrient cycling and other processes, to evaluate how the diversity, abundance and similarity of the targeted genes responded to forest-to-pasture conversion. We also evaluated whether these parameters were reestablished with secondary forest growth. A spatially nested scheme was employed to sample a primary forest, two pastures (6 and 38 years old) and a secondary forest. Both pastures had significantly lower microbial functional genes richness and diversity when compared to the primary forest. Gene composition and turnover were also significantly modified with land use change. Edaphic traits associated with soil acidity, iron availability, soil texture and organic matter concentration were correlated with these gene changes. Although primary and secondary forests showed similar functional gene richness and diversity, there were differences in gene composition and turnover, suggesting that community recovery was not complete in the secondary forest. Gene association analysis revealed that response to ecosystem conversion varied significantly across functional gene groups, with genes linked to carbon and nitrogen cycling mostly altered. This study indicates that diversity and abundance of numerous environmentally important genes respond to forest-to-pasture conversion and hence have the potential to affect the related processes at an ecosystem scale. PMID:24806276

  10. Global pattern of soil carbon losses due to the conversion of forests to agricultural land.

    PubMed

    Wei, Xiaorong; Shao, Mingan; Gale, William; Li, Linhai

    2014-01-01

    Several reviews have analyzed the factors that affect the change in soil organic C (SOC) when forest is converted to agricultural land; however, the effects of forest type and cultivation stage on these changes have generally been overlooked. We collated observations from 453 paired or chronosequential sites where forests have been converted to agricultural land and then assessed the effects of forest type, cultivation stage, climate factors, and soil properties on the change in the SOC stock and the SOC turnover rate constant (k). The percent decrease in SOC stocks and the turnover rate constants both varied significantly according to forest type and cultivation stage. The largest decrease in SOC stocks was observed in temperate regions (52% decrease), followed by tropical regions (41% decrease) and boreal regions (31% decrease). Climate and soil factors affected the decrease in SOC stocks. The SOC turnover rate constant after the conversion of forests to agricultural land increased with the mean annual precipitation and temperature. To our knowledge, this is the first time that original forest type was considered when evaluating changes in SOC after being converted to agricultural land. The differences between forest types should be considered when calculating global changes in SOC stocks. PMID:24513580

  11. Archaeal Community Changes Associated with Cultivation of Amazon Forest Soil with Oil Palm

    PubMed Central

    Tupinambá, Daiva Domenech; Cantão, Maurício Egídio; Costa, Ohana Yonara Assis; Bergmann, Jessica Carvalho; Kruger, Ricardo Henrique; Kyaw, Cynthia Maria; Barreto, Cristine Chaves; Quirino, Betania Ferraz

    2016-01-01

    This study compared soil archaeal communities of the Amazon forest with that of an adjacent area under oil palm cultivation by 16S ribosomal RNA gene pyrosequencing. Species richness and diversity were greater in native forest soil than in the oil palm-cultivated area, and 130 OTUs (13.7%) were shared between these areas. Among the classified sequences, Thaumarchaeota were predominant in the native forest, whereas Euryarchaeota were predominant in the oil palm-cultivated area. Archaeal species diversity was 1.7 times higher in the native forest soil, according to the Simpson diversity index, and the Chao1 index showed that richness was five times higher in the native forest soil. A phylogenetic tree of unclassified Thaumarchaeota sequences showed that most of the OTUs belong to Miscellaneous Crenarchaeotic Group. Several archaeal genera involved in nutrient cycling (e.g., methanogens and ammonia oxidizers) were identified in both areas, but significant differences were found in the relative abundances of Candidatus Nitrososphaera and unclassified Soil Crenarchaeotic Group (prevalent in the native forest) and Candidatus Nitrosotalea and unclassified Terrestrial Group (prevalent in the oil palm-cultivated area). More studies are needed to culture some of these Archaea in the laboratory so that their metabolism and physiology can be studied. PMID:27006640

  12. Microbial functional diversity in a mediterranean forest soil: impact of soil nitrogen availability

    NASA Astrophysics Data System (ADS)

    Dalmonech, D.; Lagomarsino, A.; Moscatelli, M. C.

    2009-04-01

    Beneficial or negative effects of N deposition on forest soil are strongly linked to the activity of microbial biomass and enzyme activities because they regulate soil quality and functioning due to their involvement in organic matter dynamics, nutrient cycling and decomposition processes. Moreover, because the ability of an ecosystem to withstand serious disturbances may depend in part on the microbial component of the system, by characterizing microbial functional diversity we may be able to better understand and manipulate ecosystem processes. Changes in the biodiversity of the soil microbial community are likely to be important in relation to maintenance of soil ecosystem function because the microbial communities influence the potential of soils for enzyme-mediated substrate catalysis. Objective of this study was to evaluate how soil N availability affected microbial functional diversity in a 4 months laboratory experiment. The incubation experiment was carried out with an organo-mineral soil collected in a Quercus cerris forest at the Roccarespampani site (Central Italy, Viterbo). All samples were incubated at 28°C and were kept to a water content between 55 and 65% of the water holding capacity. Different amount of N (NH4NO3) were added as solution once a week in order to mimic the N wet deposition and to let microbial community deal with a slow increase in time of inorganic N content. The amount of nutrient solutions was chosen depending on the average soil-water loss due to evaporation in one week. The total amount of N-NH4NO3 was chosen to be comparable with the range of N depositions currently reported in European forests, i.e. between 1 and 75 kg N ha-1 y-1. The total amount added at the end of incubation varied from 0, 10, 25, 50 and 75 kg N ha-1. Distilled water was added in the control soil in order to provide the same amount of solution as the treated soils. In order to discriminate the effect of N, the NH4NO3 solutions were adjusted to soil pH and

  13. EFFECT OF SIMULATED ACID RAIN ON NITRIFICATION AND NITROGEN MINERALIZATION IN FOREST SOILS

    EPA Science Inventory

    To determine the possible microbiological changes in soil resulting from acid rain, columns containing samples of forest soils were leached with either a continuous application of 100cm of simulated acid rain (pH3.2-4.1) at 5 cm/hour or an intermittent 1.5-hour application of 1.2...

  14. HYDRAULIC REDISTRIBUTION OF SOIL WATER BY ROOTS IN FORESTS OF THE PACIFIC NORTHWEST

    EPA Science Inventory

    One aspect of structural complexity of forest canopies is the root system structure belowground, which influences patterns of soil water utilization by trees. Deeply rooted trees and other plants can hydraulically lift water via their roots from several m below the soil surface ...

  15. Effect of oil and oil products on lipase activity in gray forest soil

    NASA Astrophysics Data System (ADS)

    Kireeva, N. A.; Tarasenko, E. M.; Shamaeva, A. A.; Novoselova, E. I.

    2006-08-01

    The effect of different rates of oil and oil products on the lipase activity in gray forest soil was studied under field and laboratory conditions. It was found that hydrocarbons activate the lipolytic activity of the soil. Along with the activation of lipolysis, an increase in the number of hydrocarbon-oxidizing microorganisms and a decrease in the content of oil products were observed.

  16. Effect of land-use practice on soil moisture variability for soils covered with dense forest vegetation of Puerto Rico

    NASA Technical Reports Server (NTRS)

    Tsegaye, T.; Coleman, T.; Senwo, Z.; Shaffer, D.; Zou, X.

    1998-01-01

    Little is known about the landuse management effect on soil moisture and soil pH distribution on a landscape covered with dense tropical forest vegetation. This study was conducted at three locations where the history of the landuse management is different. Soil moisture was measured using a 6-cm three-rod Time Domain Reflectometery (TDR) probe. Disturbed soil samples were taken from the top 5-cm at the up, mid, and foothill landscape position from the same spots where soil moisture was measured. The results showed that soil moisture varies with landscape position and depth at all three locations. Soil pH and moisture variability were found to be affected by the change in landuse management and landscape position. Soil moisture distribution usually expected to be relatively higher in the foothill (P3) area of these forests than the uphill (P1) position. However, our results indicated that in the Luquillo and Guanica site the surface soil moisture was significantly higher for P1 than P3 position. These suggest that the surface and subsurface drainage in these two sites may have been poor due to the nature of soil formation and type.

  17. Spectral Survey of Irrigated Region Corps and Soils

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The applications of remote sensing techniques to spectral surveys of irrigation, crops, and soils are reported. Topics discussed include: (1) canopy temperature as an indication of plant water stress, (2) temperature of soils and of crop canopies differing in water conditions, (3) ERTS project, (4) spectrum matching and pattern recognition, (5) photographic procedures and interpretation, (6) interaction of light with plants, and (7) plant physiological and histological factors.

  18. Soil carbon stocks and their rates of accumulation and loss in a boreal forest landscape

    USGS Publications Warehouse

    Rapalee, G.; Trumbore, S.E.; Davidson, E.A.; Harden, J.W.; Veldhuis, H.

    1998-01-01

    Boreal forests and wetlands are thought to be significant carbon sinks, and they could become net C sources as the Earth warms. Most of the C of boreal forest ecosystems is stored in the moss layer and in the soil. The objective of this study was to estimate soil C stocks (including moss layers) and rates of accumulation and loss for a 733 km2 area of the BOReal Ecosystem-Atmosphere Study site in northern Manitoba, using data from smaller-scale intensive field studies. A simple process-based model developed from measurements of soil C inventories and radiocarbon was used to relate soil C storage and dynamics to soil drainage and forest stand age. Soil C stocks covary with soil drainage class, with the largest C stocks occurring in poorly drained sites. Estimated rates of soil C accumulation or loss are sensitive to the estimated decomposition constants for the large pool of deep soil C, and improved understanding of deep soil C decomposition is needed. While the upper moss layers regrow and accumulate C after fires, the deep C dynamics vary across the landscape, from a small net sink to a significant source. Estimated net soil C accumulation, averaged for the entire 733 km2 area, was 20 g C m-2 yr-1 (28 g C m-2 yr-1 accumulation in surface mosses offset by 8 g C m-2 yr-1 lost from deep C pools) in a year with no fire. Most of the C accumulated in poorly and very poorly drained soils (peatlands and wetlands). Burning of the moss layer in only 1% of uplands would offset the C stored in the remaining 99% of the area. Significant interannual variability in C storage is expected because of the irregular occurrence of fire in space and time. The effects of climate change and management on fire frequency and on decomposition of immense deep soil C stocks are key to understanding future C budgets in boreal forests.

  19. 7 CFR 600.9 - Major land resource area soil survey offices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Major land resource area soil survey offices. 600.9... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil... soil survey production. Major land resource area soil survey offices (MO) provide the...

  20. 7 CFR 600.9 - Major land resource area soil survey offices.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Major land resource area soil survey offices. 600.9... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil... soil survey production. Major land resource area soil survey offices (MO) provide the...

  1. 7 CFR 600.9 - Major land resource area soil survey offices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Major land resource area soil survey offices. 600.9... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil... soil survey production. Major land resource area soil survey offices (MO) provide the...

  2. 7 CFR 600.9 - Major land resource area soil survey offices.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Major land resource area soil survey offices. 600.9... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil... soil survey production. Major land resource area soil survey offices (MO) provide the...

  3. 7 CFR 600.9 - Major land resource area soil survey offices.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Major land resource area soil survey offices. 600.9... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL ORGANIZATION § 600.9 Major land resource area soil... soil survey production. Major land resource area soil survey offices (MO) provide the...

  4. A meta-analysis of soil microbial biomass responses to forest disturbances

    PubMed Central

    Holden, Sandra R.; Treseder, Kathleen K.

    2013-01-01

    Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm) and biotic (insect, pathogen) disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7, 19.1, and 41.7% reductions in microbial biomass, respectively). In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics. PMID:23801985

  5. Taxonomical and functional microbial responses to agriculture management of Amazon forest soils

    NASA Astrophysics Data System (ADS)

    Kuramae, Eiko; Navarrete, Acácio; Mendes, Lucas; de Hollander, Mattias; van Veen, Johannes; Tsai, Siu

    2013-04-01

    Land-use change is one of the greatest threats to biodiversity worldwide, and one of the most devastating changes in the use of land, especially in the tropics, is the conversion of forest to crop lands. Southeast Amazon region is considered the largest agricultural frontier in the world, where native forests are converted into soybean crop fields, a fact that highlights the social and economic importance of this system to Brazil. This study firstly, focused on the impact of land-use changes and agriculture management of Amazon forest soils on the size and composition of the acidobacterial community. Taxon-specific quantitative real-time PCR (qPCR) and pyrosequencing of 16S rRNA gene were applied to study the acidobacterial community in bulk soil samples from croplands, adjacent native forests and rhizosphere of soybean. Based on qPCR measurements, Acidobacteria accounted for 23%, 18% and 14% of the total bacterial signal in forest soils, cropland soils and soybean rhizosphere samples, respectively. From the sequences of Bacteria domain, the phylum Acidobacteria represented 28%, 16% and 17% of the sequences from forest soils, cropland soils and soybean rhizosphere samples, respectively. Acidobacteria subgroups 2-8, 10, 11, 13, 17, 18, 22 and 25 were detected with subgroup 1 as dominant among them. Subgroups 4, 6 and 7 were significantly higher in cropland soils than in forest soils, which subgroups respond to decrease of soil Aluminium. Subgroups 6 and 7 respond to high content of soil Ca, Mg, Zn, P, Fe, Mn and B. The results showed differential response of the Acidobacteria subgroups to abiotic soil factors, and indicated acidobacterial subgroups as potential early-warning bio-indicators of agricultural soil management effects in the Amazon area. Secondly, using 454 pyrosequencing, we investigated the metabolic diversity of microbial communities colonizing the rhizosphere and the bulk soil associated to soybean. The rhizosphere presented an overrepresentation of

  6. Soil Carbon Stocks Decrease following Conversion of Secondary Forests to Rubber (Hevea brasiliensis) Plantations

    PubMed Central

    de Blécourt, Marleen; Brumme, Rainer; Xu, Jianchu; Corre, Marife D.; Veldkamp, Edzo

    2013-01-01

    Forest-to-rubber plantation conversion is an important land-use change in the tropical region, for which the impacts on soil carbon stocks have hardly been studied. In montane mainland southeast Asia, monoculture rubber plantations cover 1.5 million ha and the conversion from secondary forests to rubber plantations is predicted to cause a fourfold expansion by 2050. Our study, conducted in southern Yunnan province, China, aimed to quantify the changes in soil carbon stocks following the conversion from secondary forests to rubber plantations. We sampled 11 rubber plantations ranging in age from 5 to 46 years and seven secondary forest plots using a space-for-time substitution approach. We found that forest-to-rubber plantation conversion resulted in losses of soil carbon stocks by an average of 37.4±4.7 (SE) Mg C ha−1 in the entire 1.2-m depth over a time period of 46 years, which was equal to 19.3±2.7% of the initial soil carbon stocks in the secondary forests. This decline in soil carbon stocks was much larger than differences between published aboveground carbon stocks of rubber plantations and secondary forests, which range from a loss of 18 Mg C ha−1 to an increase of 8 Mg C ha−1. In the topsoil, carbon stocks declined exponentially with years since deforestation and reached a steady state at around 20 years. Although the IPCC tier 1 method assumes that soil carbon changes from forest-to-rubber plantation conversions are zero, our findings show that they need to be included to avoid errors in estimating overall ecosystem carbon fluxes. PMID:23894456

  7. Soil carbon stocks decrease following conversion of secondary forests to rubber (Hevea brasiliensis) plantations.

    PubMed

    de Blécourt, Marleen; Brumme, Rainer; Xu, Jianchu; Corre, Marife D; Veldkamp, Edzo

    2013-01-01

    Forest-to-rubber plantation conversion is an important land-use change in the tropical region, for which the impacts on soil carbon stocks have hardly been studied. In montane mainland southeast Asia, monoculture rubber plantations cover 1.5 million ha and the conversion from secondary forests to rubber plantations is predicted to cause a fourfold expansion by 2050. Our study, conducted in southern Yunnan province, China, aimed to quantify the changes in soil carbon stocks following the conversion from secondary forests to rubber plantations. We sampled 11 rubber plantations ranging in age from 5 to 46 years and seven secondary forest plots using a space-for-time substitution approach. We found that forest-to-rubber plantation conversion resulted in losses of soil carbon stocks by an average of 37.4±4.7 (SE) Mg C ha(-1) in the entire 1.2-m depth over a time period of 46 years, which was equal to 19.3±2.7% of the initial soil carbon stocks in the secondary forests. This decline in soil carbon stocks was much larger than differences between published aboveground carbon stocks of rubber plantations and secondary forests, which range from a loss of 18 Mg C ha(-1) to an increase of 8 Mg C ha(-1). In the topsoil, carbon stocks declined exponentially with years since deforestation and reached a steady state at around 20 years. Although the IPCC tier 1 method assumes that soil carbon changes from forest-to-rubber plantation conversions are zero, our findings show that they need to be included to avoid errors in estimating overall ecosystem carbon fluxes. PMID:23894456

  8. [Soil nitrous oxide emission in four temperate forests in northeastern China].

    PubMed

    Wang, Ying; Wang, Chuan-Kuan; Fu, Min-Jie; Liu, Shi; Wang, Xing-Chang

    2009-05-01

    Seasonal dynamics of N2O flux and its controlling factors for four representative temperate forests in northeastern China were examined with a static closed chamber-gas chromatograph technique. These forests were Korean pine (Pinus koraiensis) plantation, Dahurian larch (Larix gmelinii) plantation, Mongolian oak ( Quercus mongolica) forest and hardwood broadleaved forest (dominated by Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense). The results showed that all ecosystems were overall atmospheric N2O source during the growing season. The N2O flux (microg x m(-2) x h(-1)) decreased in order of the hardwood broadleaved forest (21.0 +/- 4.9) > the pine plantation (17.6 +/- 4. 6) > the larch plantation (9.8 +/- 5.9) > the oak forest (1.6 +/- 12.6). Overall, there was no consistent seasonal pattern in N2O flux for the four ecosystems. The N2O flux was significantly positively correlated to soil gravimetric water content (0-10 cm depth) consistently for all ecosystems, but significantly negatively correlated to NO3(-)-N content for each ecosystem. However, the responses of N2O flux to soil temperature and NH4(+)-N differed among the ecosystems. The N2O fluxes for the coniferous plantations were positively correlated to NH4(+)-N, but not correlated to the soil temperature at 5 cm depth; while those for the broadleaved forests displayed an opposite trend. The soil water content was the dominator of soil N2O emission for the forests in 2007 perhaps resulting from relative drought in the year. Interactions of vegetation type, environmental factor, and nitrogen availability to soil N2O emission should be further studied in the future. PMID:19803152

  9. Fast changes in seasonal forest communities due to soil moisture increase after damming.

    PubMed

    do Vale, Vagner Santiago; Schiavini, Ivan; Araújo, Glein Monteiro; Gusson, André Eduardo; Lopes, Sérgio de Faria; de Oliveira, Ana Paula; do Prado-Júnior, Jamir Afonso; Arantes, Carolina de Silvério; Dias-Neto, Olavo Custodio

    2013-12-01

    Local changes caused by dams can have drastic consequences for ecosystems, not only because they change the water regime but also the modification on lakeshore areas. Thus, this work aimed to determine the changes in soil moisture after damming, to understand the consequences of this modification on the arboreal community of dry forests, some of the most endangered systems on the planet. We studied these changes in soil moisture and the arboreal community in three dry forests in the Araguari River Basin, after two dams construction in 2005 and 2006, and the potential effects on these forests. For this, plots of 20 m x 10 m were distributed close to the impoundment margin and perpendicular to the dam margin in two deciduous dry forests and one semi-deciduous dry forest located in Southeastern Brazil, totaling 3.6 ha sampled. Besides, soil analysis were undertaken before and after impoundment at three different depths (0-10, 20-30 and 40-50 cm). A tree (minimum DBH of 4.77 cm) community inventory was made before (TO) and at two (T2) and four (T4) years after damming. Annual dynamic rates of all communities were calculated, and statistical tests were used to determine changes in soil moisture and tree communities. The analyses confirmed soil moisture increases in all forests, especially during the dry season and at sites closer to the reservoir; besides, an increase in basal area due to the fast growth of many trees was observed. The highest turnover occurred in the first two years after impoundment, mainly due to the higher tree mortality especially of those closer to the dam margin. All forests showed reductions in dynamic rates for subsequent years (T2-T4), indicating that these forests tended to stabilize after a strong initial impact. The modifications were more extensive in the deciduous forests, probably because the dry period resulted more rigorous in these forests when compared to semideciduous forest. The new shorelines created by damming increased soil

  10. Different tree species affect soil respiration spatial distribution in a subtropical forest of southern Taiwan

    NASA Astrophysics Data System (ADS)

    Chiang, Po-Neng; Yu, Jui-Chu; Wang, Ya-nan; Lai, Yen-Jen

    2014-05-01

    Global forests contain 69% of total carbon stored in forest soil and litter. But the carbon storage ability and release rate of warming gases of forest soil also affect global climate change. Soil carbon cycling processes are paid much attention by ecological scientists and policy makers because of the possibility of carbon being stored in soil via land use management. Soil respiration contributed large part of terrestrial carbon flux, but the relationship of soil respiration and climate change was still obscurity. Most of soil respiration researches focus on template and tropical area, little was known that in subtropical area. Afforestation is one of solutions to mitigate CO2 increase and to sequestrate CO2 in tree and soil. Therefore, the objective of this study is to clarify the relationship of tree species and soil respiration distribution in subtropical broad-leaves plantation in southern Taiwan. The research site located on southern Taiwan was sugarcane farm before 2002. The sugarcane was removed and fourteen broadleaved tree species were planted in 2002-2005. Sixteen plots (250m*250m) were set on 1 km2 area, each plot contained 4 subplots (170m2). The forest biomass (i.e. tree height, DBH) understory biomass, litter, and soil C were measured and analyzed at 2011 to 2012. Soil respiration measurement was sampled in each subplot in each month. The soil belongs to Entisol with over 60% of sandstone. The soil pH is 5.5 with low base cations because of high sand percentage. Soil carbon storage showed significantly negative relationship with soil bulk density (p<0.001) in research site. The differences of distribution of live tree C pool among 16 plots were affected by growth characteristic of tree species. Data showed that the accumulation amount of litterfall was highest in December to February and lowest in June. Different tree species planted in 16 plots, resulting in high spatial variation of litterfall amount. It also affected total amount of litterfall

  11. The ash in forest fire affected soils control the soil losses. Part 1. The pioneer research

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Pereira, Paulo

    2013-04-01

    After forest fires, the ash and the remaining vegetation cover on the soil surface are the main protection against erosion agents. The control ash exert on runoff generation mechanism was researched during the 90's (Cerdà, 1998a; 1998b). This pioneer research demonstrated that after forest fires there is a short period of time that runoff and surface wash by water is controlled by the high infiltration rates achieved by the soil, which were high due to the effect of ash acting as a mulch. The research of Cerdà (1998a; 1998b) also contributed to demonstrate that runoff was enhanced four month later upon the wash of the ash by the runoff, but also due to the removal of ash due to dissolution and water infiltration. As a consequence of the ephemeral ash cover the runoff and erosion reached the peak after the removal of the ash (usually four month), and for two years the soil erosion reached the peak (Cerdà, 1998a). Research developed during the last decade shown that the ash and the litter cover together contribute to reduce the soil losses after the forest fire (Cerdà and Doerr, 2008). The fate of the ash is related to the climatic conditions of the post-fire season, as intense thunderstorms erode the ash layer and low intensity rainfall contribute to a higher infiltration rate and the recovery of the vegetation. Another, key factor found during the last two decades that determine the fate of the ash and the soil and water losses is the impact of the fauna (Cerdà and Doerr, 2010). During the last decade new techniques were developed to study the impact of ash in the soil system, such as the one to monitor the ash changes by means of high spatial resolution photography (Pérez Cabello et al., 2012), and laboratory approaches that show the impact of ash as a key factor in the soil hydrology throughout the control they exert on the soil water repellency (Bodí et al., 2012). Laboratory approaches also shown that the fire severity is a key factor on the ash chemical

  12. Soil carbon dynamics in pastures and forests of the eastern Amazon

    SciTech Connect

    Davidson, E.A.; Nepstad, D.C.; Trumbore, S.E. Univ. of California, Irvine )

    1993-06-01

    There is a dearth of information on below-ground C budgets of tropical forests and the ecosystems that are replacing them. Mean flux of CO[sub 2] from the soil surface was 0.29 and 0.14 g C m[sup [minus]2] h[sup [minus]1] in primary forests and degraded pastures, respectively, near Paragominas, Brazil. Litterfall and fine root inputs were about two times greater in forests than pastures. The [sup 14]C and [sup 13]C contents of SOM and CO[sub 2] in a pasture cleared in 1975 show that much of the labile forest SOM has been lost and little new C has been added by pasture vegetation. A preliminary estimate of the cumulative net C loss from the pasture soil is 2.7 kg C m[sup [minus]2] (about 10% of the forest soil C inventory), and it is still losing about 0.09 kg C m[sup [minus]2] yr[sup [minus]1]. Most of the soil C turnover occurs near the surface, but most of the long-term C storage occurs below 1 m in these oxisols. About 10% of the soil C at depth has a mean residence time of years to decades and is input by the deep roots of trees in this seasonally droughty region. Grasses have fewer deep roots, and about 1/3 of the total C lost from pasture soil was from below 1 m depth.

  13. Climate controls on forest soil C isotope ratios in the Southern Appalachian Mountains

    SciTech Connect

    Garten, C.T. Jr.; Cooper, L.W.; Post, W.M. III; Hanson, P.J.

    2000-04-01

    A large portion of terrestrial carbon (C) resides in soil organic carbon (SOC). The dynamics of this large reservoir depend on many factors, including climate. Measurements of {sup 13}C:{sup 12}C ratios, C concentrations, and C:N ratios at six forest sites in the Southern Appalachian Mountains (USA) were used to explore several hypotheses concerning the relative importance of factors that control soil organic matter (SOM) decomposition and SOC turnover. Mean {delta}{sup 13}C values increased with soil depth and decreasing C concentrations along a continuum from fresh litter inputs to more decomposed soil constituents. Data from the six forest sites, in combination with data from a literature review, indicate that the extent of change in {delta}{sup 13}C values from forest litter inputs to mineral soil is significantly associated with mean annual temperature. The findings support a conceptual model of vertical changes in forest soil {delta}{sup 13}C values, C concentrations, and C:N ratios that are interrelated through climate controls on decomposition. The authors hypothesize that, if other environmental factors are not limiting, then temperature and litter quality indirectly control the extent of isotopic fractionation during SOM decomposition in temperate forest ecosystems.

  14. Soil responses to management, increased precipitation, and added nitrogen in ponderosa pine forests.

    PubMed

    Hungate, Bruce A; Hart, Stephen C; Selmants, Paul C; Boyle, Sarah I; Gehring, Catherine A

    2007-07-01

    Forest management, climatic change, and atmospheric N deposition can affect soil biogeochemistry, but their combined effects are not well understood. We examined the effects of water and N amendments and forest thinning and burning on soil N pools and fluxes in ponderosa pine forests near Flagstaff, Arizona (USA). Using a 15N-depleted fertilizer, we also documented the distribution of added N into soil N pools. Because thinning and burning can increase soil water content and N availability, we hypothesized that these changes would alleviate water and N limitation of soil processes, causing smaller responses to added N and water in the restored stand. We found little support for this hypothesis. Responses of fine root biomass, potential net N mineralization, and the soil microbial N to water and N amendments were mostly unaffected by stand management. Most of the soil processes we examined were limited by N and water, and the increased N and soil water availability caused by forest restoration was insufficient to alleviate these limitations. For example, N addition caused a larger increase in potential net nitrification in the restored stand, and at a given level of soil N availability, N addition had a larger effect on soil microbial N in the restored stand. Possibly, forest restoration increased the availability of some other limiting resource, amplifying responses to added N and water. Tracer N recoveries in roots and in the forest floor were lower in the restored stand. Natural abundance delta15N of labile soil N pools were higher in the restored stand, consistent with a more open N cycle. We conclude that thinning and burning open up the N cycle, at least in the short-term, and that these changes are amplified by enhanced precipitation and N additions. Our results suggest that thinning and burning in ponderosa pine forests will not increase their resistance to changes in soil N dynamics resulting from increased atmospheric N deposition or increased

  15. Effects of Native Forest Restoration on Soil Hydraulic Properties, Auwahi, Maui

    NASA Astrophysics Data System (ADS)

    Perkins, K. S.; Nimmo, J. R.; Medeiros, A.

    2012-12-01

    Over historic time Hawai'i's dryland forests have been largely replaced by grasslands for grazing livestock; less than 10% of original dryland forest habitat remains. The reestablishment of native ecosystems on land severely degraded by long-term alternative use requires reversal of the impacts of erosion, organic-matter loss, and soil structural damage on soil hydraulic properties. These reforestation efforts depend on restoring soil ecological function, including soil hydraulic properties. We hypothesized that reforestation can measurably change soil hydraulic properties over restoration timescales. At a site on the island of Maui (Hawai'i, USA), we measured infiltration rate (Kfs), hydrophobicity, and abundance of preferential flow channels in a deforested grassland and in an adjacent exclosure where active reforestation has been going on for fourteen years. Results from field experiments support the hypothesis that reforestation at the Auwahi site has significantly altered plant-relevant soil hydraulic properties.

  16. Factors for Microbial Carbon Sources in Organic and Mineral Soils from Eastern United States Deciduous Forests

    NASA Astrophysics Data System (ADS)

    Stitt, C.; McFarlane, K. J.

    2013-12-01

    Forest soils represent a large portion of global terrestrial carbon; however, which soil carbon sources are used by soil microbes and respired as carbon dioxide (CO2) is not well known. This study will focus on characterizing microbial carbon sources from organic and mineral soils from four eastern United States deciduous forests using the unique radiocarbon tracer, 14C. Results from the dark incubation of the organic and mineral soils are heavily influenced by site characteristics when incubated at microbial optimal activity temperature. The sites with the most similarities are statically the same (p> 0.10). The sites with considerable differences in temperature, texture, and location are statically different concluding that site characteristics play a role in soil respiration.

  17. Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions

    PubMed Central

    Hengl, Tomislav; Heuvelink, Gerard B. M.; Kempen, Bas; Leenaars, Johan G. B.; Walsh, Markus G.; Shepherd, Keith D.; Sila, Andrew; MacMillan, Robert A.; Mendes de Jesus, Jorge; Tamene, Lulseged; Tondoh, Jérôme E.

    2015-01-01

    80% of arable land in Africa has low soil fertility and suffers from physical soil problems. Additionally, significant amounts of nutrients are lost every year due to unsustainable soil management practices. This is partially the result of insufficient use of soil management knowledge. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. Over the period 2008–2014, the AfSIS project compiled two point data sets: the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site database. These data sets contain over 28 thousand sampling locations and represent the most comprehensive soil sample data sets of the African continent to date. Utilizing these point data sets in combination with a large number of covariates, we have generated a series of spatial predictions of soil properties relevant to the agricultural management—organic carbon, pH, sand, silt and clay fractions, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content and exchangeable bases (Ca, K, Mg, Na). We specifically investigate differences between two predictive approaches: random forests and linear regression. Results of 5-fold cross-validation demonstrate that the random forests algorithm consistently outperforms the linear regression algorithm, with average decreases of 15–75% in Root Mean Squared Error (RMSE) across soil properties and depths. Fitting and running random forests models takes an order of magnitude more time and the modelling success is sensitive to artifacts in the input data, but as long as quality-controlled point data are provided, an increase in soil mapping accuracy can be expected. Results also indicate that globally predicted soil classes (USDA Soil Taxonomy, especially Alfisols and Mollisols) help improve continental scale soil property mapping, and are among the most important predictors. This indicates a promising potential for transferring pedological

  18. Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions.

    PubMed

    Hengl, Tomislav; Heuvelink, Gerard B M; Kempen, Bas; Leenaars, Johan G B; Walsh, Markus G; Shepherd, Keith D; Sila, Andrew; MacMillan, Robert A; Mendes de Jesus, Jorge; Tamene, Lulseged; Tondoh, Jérôme E

    2015-01-01

    80% of arable land in Africa has low soil fertility and suffers from physical soil problems. Additionally, significant amounts of nutrients are lost every year due to unsustainable soil management practices. This is partially the result of insufficient use of soil management knowledge. To help bridge the soil information gap in Africa, the Africa Soil Information Service (AfSIS) project was established in 2008. Over the period 2008-2014, the AfSIS project compiled two point data sets: the Africa Soil Profiles (legacy) database and the AfSIS Sentinel Site database. These data sets contain over 28 thousand sampling locations and represent the most comprehensive soil sample data sets of the African continent to date. Utilizing these point data sets in combination with a large number of covariates, we have generated a series of spatial predictions of soil properties relevant to the agricultural management--organic carbon, pH, sand, silt and clay fractions, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content and exchangeable bases (Ca, K, Mg, Na). We specifically investigate differences between two predictive approaches: random forests and linear regression. Results of 5-fold cross-validation demonstrate that the random forests algorithm consistently outperforms the linear regression algorithm, with average decreases of 15-75% in Root Mean Squared Error (RMSE) across soil properties and depths. Fitting and running random forests models takes an order of magnitude more time and the modelling success is sensitive to artifacts in the input data, but as long as quality-controlled point data are provided, an increase in soil mapping accuracy can be expected. Results also indicate that globally predicted soil classes (USDA Soil Taxonomy, especially Alfisols and Mollisols) help improve continental scale soil property mapping, and are among the most important predictors. This indicates a promising potential for transferring pedological

  19. Molecular hydrogen uptake by soils in forest, desert, and marsh ecosystems in California

    NASA Astrophysics Data System (ADS)

    Smith-Downey, Nicole V.; Randerson, James T.; Eiler, John M.

    2008-09-01

    The mechanism and environmental controls on soil hydrogen (H2) uptake are not well understood but are essential for understanding the atmospheric H2 budget. Field observations of soil H2 uptake are limited, and here we present the results from a series of measurements in forest, desert, and marsh ecosystems in southern California. We measured soil H2 fluxes using flux chambers from September 2004 to July 2005. Mean H2 flux rates and standard deviations were -7.9 + -4.2, -7.6 + -5.3 and -7.5 + -3.4 nmol m-2 s-1 for the forest, desert, and marsh, respectively (corresponding to deposition velocities of 0.063 + -0.029, 0.051 + -0.036, 0.035 + -0.013 cm s-1). Soil profile measurements showed that H2 mixing ratios were between 3% and 51% of atmospheric levels at 10 cm and that the penetration of H2 into deeper soil layers increased with soil drying. Soil removal experiments in the forest demonstrated that the litter layer did not actively consume H2, the removal of this layer increased uptake by deeper soil layers, and the exposure of subsurface soil layers to ambient atmospheric H2 levels substantially increased their rate of uptake. Similar soil removal experiments at the desert site showed that extremely dry surface soils did not consume H2 and that fluxes at the surface increased when these inactive layers were removed. We present a model of soil H2 fluxes and show that the diffusivity of soils, along with the vertical distribution of layers that actively consume H2 regulate surface fluxes. We found that soil organic matter, CO2 fluxes, and ecosystem type were not strong controllers of H2 uptake. Our experiments highlight H2 diffusion into soils as an important limit on fluxes and that minimum moisture level is needed to initiate microbial uptake.

  20. Effects of Experimental Drought on Soil Respiration and Radiocarbon Efflux from a Temperate Forest Soil

    NASA Astrophysics Data System (ADS)

    Borken, W.; Savage, K.; Davidson, E. A.; Trumbore, S. E.

    2002-12-01

    Soil respiration is affected by the water content of both mineral soil and organic horizons. A throughfall exclusion experiment was established at the Harvard Forest in central Massachusetts to quantify the importance of this variation. Weekly measurements of soil respiration began in the spring of 2001, with 4 manual flux chambers installed in each of 6 plots (5 x 5 m). In July 2001, sub-canopy roofs with translucent plastic panels were installed in 3 of the plots, while the other 3 control plots were left open. Temperature probes, TDR probes, and gas tubes were buried at 4 depths in each plot. DC half-bridges for measuring water content of organic material were installed in the O horizons. The roofs were removed in the autumn to allow leaf-fall and snowfall and were reinstalled in the spring of 2002. Hourly automated flux measurements, with one chamber in each of the 6 plots, were also started in the spring of 2002. Radiocarbon contents of CO2 emissions and concentrations within the soil have been measured periodically. Soil respiration rates were similar in control and treatment plots throughout June 2001, but once throughfall exclusion began in July, the fluxes declined in the exclusion plots. During the 84 days of 2001 that the roofs were in place, 168 mm of throughfall was diverted, and the cumulative soil respiration was 30% lower in exclusion plots compared to control plots (241 and 341 g C m-2, respectively). The automated chamber system revealed an increase in soil respiration in the control plots within minutes of a precipitation event. Soil respiration declined to pre-wetting values at the same time that the litter layer dried, about 48 hours after wetting. The Δ14CO2 from soil respiration ranged from 95 to 141‰ in the control plots and from 88 to 263‰ in the exclusion plots. The Δ14CO2 from root respiration and recently fixed carbon (within 1 year) should be 77‰ (the value of the atmosphere in 2001), so the observed values indicate that the

  1. Declines in Soil pH due to Anthropogenic Nitrogen Inputs Alter Buffering and Exchange Reactions in Tropical Forest Soils

    NASA Astrophysics Data System (ADS)

    Lohse, K. A.

    2003-12-01

    Anthropogenic nitrogen (N) inputs may alter tropical soil buffering and exchange reactions that have important implications for nutrient cycling, forest productivity, and downstream ecosystems. In contrast to relatively young temperate soils that are typically buffered from N inputs by base cation reactions, aluminum reactions may serve to buffer highly weathered tropical soils and result in immediate increases in aluminum mobility and toxicity. Increased nitrate losses due to chronic N inputs may also deplete residual base cations in already weathered base cation-poor soils, further acidify soils, and thereby reduce nitrate mobility through pH-dependent anion exchange reactions. To test these hypotheses, I determined soil pH and cation and anion exchange capacity (CEC and AEC) and measured base cation and aluminum soil solution losses following first-time and long-term experimental N additions from two Hawaiian tropical forest soils, a 300 year old Andisol and a 4.1 million year old Oxisol. I found that elevated base cation losses accompanied increased nitrate losses after first time N additions to the young Andisol whereas immediate and large aluminum losses were associated with increased nitrate losses from the Oxisol. In the long-term, base cation and aluminum losses increased in proportion to nitrate losses. Long-term N additions at both sites resulted in significant declines in soil pH, decreased CEC and increased AEC. These results suggest that even chronic N inputs resulting in small but elevated nitrate losses may deplete residual base cations, increase mobility and toxicity of aluminum, and potentially lead to declines in forest productivity and acidification of downstream ecosystems. These findings also suggest that AEC may provide a long-term mechanism to delay nitrate losses in tropical forests with significant variable charge that are experiencing chronic anthropogenic N inputs.

  2. Changes in microbial community characteristics and soil organic matter with nitrogen additions in two tropical forests

    SciTech Connect

    Cusack, Daniela F.; Silver, Whendee; Torn, Margaret S.; Burton, Sarah D.; Firestone, Mary

    2011-03-01

    Microbial communities and their associated enzyme activities affect the amount and chemical quality of carbon (C) in soils. Increasing nitrogen (N) deposition, particularly in N-rich tropical forests, is likely to change the composition and behavior of microbial communities and feed back on ecosystem structure and function. This study presents a novel assessment of mechanistic links between microbial responses to N deposition and shifts in soil organic matter (SOM) quality and quantity. We used phospholipid fatty acid (PLFA) analysis and microbial enzyme assays in soils to assess microbial community responses to long-term N additions in two distinct tropical rain forests. We used soil density fractionation and 13C nuclear magnetic resonance (NMR) spectroscopy to measure related changes in SOM pool sizes and chemical quality. Microbial biomass increased in response to N fertilization in both tropical forests and corresponded to declines in pools of low-density SOM. The chemical quality of this soil C pool reflected ecosystem-specific changes in microbial community composition. In the lower-elevation forest, there was an increase in gram-negative bacteria PLFA biomass, and there were significant losses of labile C chemical groups (O-alkyls). In contrast, the upper-elevation tropical forest had an increase in fungal PLFAs with N additions and declines in C groups associated with increased soil C storage (alkyls). The dynamics of microbial enzymatic activities with N addition provided a functional link between changes in microbial community structure and SOM chemistry. Ecosystem-specific changes in microbial community composition are likely to have far-reaching effects on soil carbon storage and cycling. This study indicates that microbial communities in N-rich tropical forests can be sensitive to added N, but we can expect significant variability in how ecosystem structure and function respond to N deposition among tropical forest types.

  3. Changes in microbial community characteristics and soil organic matter with nitrogen additions in two tropical forests.

    PubMed

    Cusack, Daniela F; Silver, Whendee L; Torn, Margaret S; Burton, Sarah D; Firestone, Mary K

    2011-03-01

    Microbial communities and their associated enzyme activities affect the amount and chemical quality of carbon (C) in soils. Increasing nitrogen (N) deposition, particularly in N-rich tropical forests, is likely to change the composition and behavior of microbial communities and feed back on ecosystem structure and function. This study presents a novel assessment of mechanistic links between microbial responses to N deposition and shifts in soil organic matter (SOM) quality and quantity. We used phospholipid fatty acid (PLFA) analysis and microbial enzyme assays in soils to assess microbial community responses to long-term N additions in two distinct tropical rain forests. We used soil density fractionation and 13C nuclear magnetic resonance (NMR) spectroscopy to measure related changes in SOM pool sizes and chemical quality. Microbial biomass increased in response to N fertilization in both tropical forests and corresponded to declines in pools of low-density SOM. The chemical quality of this soil C pool reflected ecosystem-specific changes in microbial community composition. In the lower-elevation forest, there was an increase in gram-negative bacteria PLFA biomass, and there were significant losses of labile C chemical groups (O-alkyls). In contrast, the upper-elevation tropical forest had an increase in fungal PLFAs with N additions and declines in C groups associated with increased soil C storage (alkyls). The dynamics of microbial enzymatic activities with N addition provided a functional link between changes in microbial community structure and SOM chemistry. Ecosystem-specific changes in microbial community composition are likely to have far-reaching effects on soil carbon storage and cycling. This study indicates that microbial communities in N-rich tropical forests can be sensitive to added N, but we can expect significant variability in how ecosystem structure and function respond to N deposition among tropical forest types. PMID:21608471

  4. Forest soil carbon inventories and dynamics along an elevation gradient in the southern Appalachian Mountains

    SciTech Connect

    Garten Jr, Charles T; Post, Wilfred M; Hanson, Paul J; Cooper, Lee W

    1999-05-01

    Soil organic carbon (SOC) was partitioned between unprotected and protected pools in six forests along an elevation gradient in the southern Appalachian Mountains using two physical methods: flotation in aqueous CaCl{sub 2} (1.4 g/mL) and wet sieving through a 0.053 mm sieve. Both methods produced results that were qualitatively and quantitatively similar. Along the elevation gradient, 28 to 53% of the SOC was associated with an unprotected pool that included forest floor O-layers and other labile soil organic matter (SOM) in various stages of decomposition. Most (71 to 83%) of the C in the mineral soil at the six forest sites was identified as protected because of its association with a heavy soil fraction (> 1.4 g/mL) or a silt-clay soil fraction. Total inventories of SOC in the forests (to a depth of 30 cm) ranged from 384 to 1244 mg C/cm{sup 2}. The turnover time of the unprotected SOC was negatively correlated (r = -0.95, p < 0.05) with mean annual air temperature (MAT) across the elevation gradient. Measured SOC inventories, annual C returns to the forest floor, and estimates of C turnover associated with the protected soil pool were used to parameterize a simple model of SOC dynamics. Steady-state predictions with the model indicated that, with no change in C inputs, the low- (235-335 m), mid- (940-1000 m), and high- (1650-1670 m) elevation forests under study might surrender {approx} 40 to 45% of their current SOC inventory following a 4 C increase in MAT. Substantial losses of unprotected SOM as a result of a warmer climate could have long-term impacts on hydrology, soil quality, and plant nutrition in forest ecosystems throughout the southern Appalachian Mountains.

  5. Long-term changes in soil pH across major forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Yang, Yuanhe; Li, Pin; He, Honglin; Zhao, Xia; Datta, Arindam; Ma, Wenhong; Zhang, Ying; Liu, Xuejun; Han, Wenxuan; Wilson, Maxwell C.; Fang, Jingyun

    2015-02-01

    Atmospheric acidic deposition has been a major environmental problem since the industrial revolution. However, our understanding of the effect of acidic deposition on soil pH is inconclusive. Here we examined temporal variations in topsoil pH and their relationships with atmospheric sulfur and nitrogen deposition across China's forests from the 1980s to the 2000s. To accomplish this goal, we conducted artificial neural network simulations using historical soil inventory data from the 1980s and a data set synthesized from literature published after 2000. Our results indicated that significant decreases in soil pH occurred in broadleaved forests, while minor changes were observed in coniferous and mixed coniferous and broadleaved forests. The magnitude of soil pH change was negatively correlated with atmospheric sulfur and nitrogen deposition. This relationship highlights the need for stringent measures that reduce sulfur and nitrogen emissions so as to maintain ecosystem structure and function.

  6. Soil Carbon Change During Fifty Years of Old-Field Forest Development

    NASA Astrophysics Data System (ADS)

    Mobley, M. L.; Heine, P. R.; Billings, S. A.; Lajtha, K.; Kramer, M. G.; Richter, D. D.

    2010-12-01

    At the Calhoun Experimental Forest, a 50-year-old loblolly pine plantation in the South Carolina Piedmont, researchers have sampled soils and trees regularly since forest establishment in 1957. The Calhoun’s archived soils and data present a unique opportunity to quantify above- and belowground carbon sequestration of an economically and ecologically important ecosystem. This research explores the changes in soil organic carbon quantity, quality, and residence times following conversion of an agricultural field to a 50-year-old pine forest. Following planting of the rapidly-growing forest in an old cotton field, almost 20 years were required to observe any increases in surficial (0-7.5cm) soil carbon. Over the 50-year period, the deepest soil layer sampled (35-60cm) has experienced an on-going and significant loss of soil carbon. Thus, after 50 years, there has been no net change in SOC content of the upper 60cm of mineral soil, despite the development of a mature pine forest canopy and the accumulation of a thick acidic mor-type organic horizon. The bomb spike in radiocarbon enrichment propagated from the surface soil in the 1960s down to the 35-60cm soil in the early 1970s, showing that “new” forest carbon entered the 35-60cm soil layer. A drop in 35-60cm δ14C nearly back to pre-bomb testing levels by the mid-1980s indicated that much of this “new” carbon had been quickly respired. Taken together, the bulk soil C and isotopic data suggest that a) subsoils are sites of active carbon cycling and b) at least some “old”, slow-turnover carbon has been lost from these deeper layers. Stable isotope values have shown divergent trends over time: accumulation of new forest organic matter at the surface has depleted 13C in surface soils, while microbial- and mycorrhizal-mediated tree root uptake of nitrogen has greatly enriched 15N in 15-60cm soils over the course of forest development. For some time, the loss of SOC at depth has been hypothesized to be the

  7. Soil CO2 efflux among four coniferous forest types of Kashmir Himalaya, India.

    PubMed

    Dar, Javid Ahmad; Ganie, Khursheed Ahmad; Sundarapandian, Somaiah

    2015-11-01

    Soil CO2 efflux was measured in four different coniferous forest types (Cedrus deodara (CD), Pinus wallichiana (PW), mixed coniferous (MC), and Abies pindrow (AP)) for a period of 2 years (April 2012 to December 2013). The monthly soil CO2 efflux ranged from 0.8 to 4.1 μmoles CO2 m(-2) s(-1) in 2012 and 1.01 to 5.48 μmoles CO2 m(-2) s(-1) in 2013. The soil CO2 efflux rate was highest in PW forest type in both the years, while it was lowest in MC and CD forest types during 2012 and 2013, respectively. Soil temperature (TS) at a depth of 10 cm ranged from 3.8 to 19.4 °C in 2012 and 3.5 to 19.1 °C in 2013 in all the four forest types. Soil moisture (MS) ranged from 19.8 to 58.6% in 2012 and 18.5 to 58.6% in 2013. Soil CO2 efflux rate was found to be significantly higher in summer than the other seasons and least during winter. Soil CO2 efflux showed a significant positive relationship with TS (R2=0.52 to 0.74), SOC% (R2=0.67), pH (R2=0.68), and shrub biomass (R2=0.51), whereas, only a weak positive relationship was found with soil moisture (R2=0.16 to 0.41), tree density (R2=0.25), tree basal area (R2=0.01), tree biomass (R2=0.07), herb biomass (R2=0.01), and forest floor litter (R2=0.02). Thus, the study indicates that soil CO2 efflux in high mountainous areas is greatly influenced by seasons, soil temperature, and other environmental factors. PMID:26514798

  8. An Integrated Study to Analyze Soil Microbial Community Structure and Metabolic Potential in Two Forest Types

    PubMed Central

    Zhang, Yuguang; Cong, Jing; Lu, Hui; Yang, Caiyun; Yang, Yunfeng; Zhou, Jizhong; Li, Diqiang

    2014-01-01

    Soil microbial metabolic potential and ecosystem function have received little attention owing to difficulties in methodology. In this study, we selected natural mature forest and natural secondary forest and analyzed the soil microbial community and metabolic potential combing the high-throughput sequencing and GeoChip technologies. Phylogenetic analysis based on 16S rRNA sequencing showed that one known archaeal phylum and 15 known bacterial phyla as well as unclassified phylotypes were presented in these forest soils, and Acidobacteria, Protecobacteria, and Actinobacteria were three of most abundant phyla. The detected microbial functional gene groups were related to different biogeochemical processes, including carbon degradation, carbon fixation, methane metabolism, nitrogen cycling, phosphorus utilization, sulfur cycling, etc. The Shannon index for detected functional gene probes was significantly higher (P<0.05) at natural secondary forest site. The regression analysis showed that a strong positive (P<0.05) correlation was existed between the soil microbial functional gene diversity and phylogenetic diversity. Mantel test showed that soil oxidizable organic carbon, soil total nitrogen and cellulose, glucanase, and amylase activities were significantly linked (P<0.05) to the relative abundance of corresponded functional gene groups. Variance partitioning analysis showed that a total of 81.58% of the variation in community structure was explained by soil chemical factors, soil temperature, and plant diversity. Therefore, the positive link of soil microbial structure and composition to functional activity related to ecosystem functioning was existed, and the natural secondary forest soil may occur the high microbial metabolic potential. Although the results can't directly reflect the actual microbial populations and functional activities, this study provides insight into the potential activity of the microbial community and associated feedback responses of the

  9. Chemical features of soils in a natural forest of West Hungary

    NASA Astrophysics Data System (ADS)

    Hofmann, Eszter; Bidló, András

    2015-04-01

    The present research focuses on the chemical results of soils formed on miocene carbonate rocks in a natural forest of West Hungary. Soil profiles derived from the Szárhalom Forest, located near the Lake Fertő, next to the city of Sopron. Six soil profiles were opened and analysed in this area. In the field the following physical parameters were evaluated from the soil profiles: transition, structure, compactness, roots, skeletal percent, colour, physical assortment, concretion and soil defect. Laboratory analysis involved the measurement of acidity, particle distribution, carbonated lime content, humus content, ammonium lactate-acetic acid soluble phosphorus- and potassium content, potassium chloride soluble calcium- and magnesium content, ethylene-diamine-tetraacetic-acid (EDTA) and diethylene-triamine-pentaacetic-acid (DTPA) soluble copper-, iron-, manganese- and zinc contents. These soils formed under a hornbeam-oak forest climate mainly and under a beech forest climate diffusely. The location and climate of the sites forms a basis of the comparison of the soils with similar base rock. The formation of the acidic and humus-rich upper layer of the soil profiles is influenced by the mineral composition and the weathering of the rocks. X-ray diffraction (Philips P W3710/PW1050 type X-ray diffractometer), thermoanalytical measurements (Mettler Toledo TGA/DSC 1 type thermogravimeter) and ICP-OES (Thermo Scientific iCAP 7000 Series) were also carried out to determine the mineral composition of the soils and the content of heavy metals. The soil samples were collected with both traditional and undisturbed (using the Kubiena box) sampling methods to enable further micromorphological investigations as well. The research is supported by the "Agroclimate-2" (VKSZ_12-1-2013-0034) joint EU-national research project. Key words: Natural forest, Miocene limestone, Mineral composition, Thermal analysis, Micromorphology

  10. Indications of nitrogen-limited methane uptake in tropical forest soils

    NASA Astrophysics Data System (ADS)

    Veldkamp, E.; Koehler, B.; Corre, M. D.

    2013-08-01

    It is estimated that tropical forest soils contribute 6.2 Tg yr-1 (28%) to global methane (CH4) uptake, which is large enough to alter CH4 accumulation in the atmosphere if significa