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Sample records for adjacent undisturbed forest

  1. Ectomycorrhizal Fungal Communities of Red Pine (Pinus densiflora) Seedlings in Disturbed Sites and Undisturbed Old Forest Sites.

    PubMed

    Lee, Eun-Hwa; Eom, Ahn-Heum

    2013-06-01

    This study aimed to investigate differences in ectomycorrhizal (ECM) fungal communities between disturbed sites and undisturbed old forest sites. ECM root tips of Pinus densiflora were collected from 4 sites disturbed by human activities and 3 undisturbed old forest sites adjacent to the disturbed sites. Results in this study showed that the number of ECM root tips, species diversity, and number of species were significantly higher in the disturbed sites than in the undisturbed sites, suggesting that the ECM fungal community structure was affected by the degree of disturbance.

  2. Trichodorus elefjohnsoni n. sp. (Nemata: Trichodoridae) from Undisturbed Appalachian Forest

    PubMed Central

    Bernard, E. C.

    1992-01-01

    A new species of Trichodoridae, Trichodorus elefjohnsoni, is described from undisturbed regions of Great Smoky Mountains National Park, United States. It resembles T. orientalis De Waele &Hashim, 1984, T. persicus De Waele &Sturhan, 1987, and T. taylori De Waele, Mancini, Roca, ' Lamberti, 1982 in arrangement of ventromedian cervical papillae and posterior preanal supplements, but differs by combinations of the following characteristics: body length 516-731 μm; spicule length 33-50 μm, spicules densely striated, constricted medially; vaginal sclerotizations ovate; one pair of lateral body pores near vulva. PMID:19283205

  3. Disentangling the drivers of taxonomic and phylogenetic beta diversities in disturbed and undisturbed subtropical forests

    PubMed Central

    Liu, Jinliang; Qian, Hong; Jin, Yi; Wu, Chuping; Chen, Jianhua; Yu, Shuquan; Wei, Xinliang; Jin, Xiaofeng; Liu, Jiajia; Yu, Mingjian

    2016-01-01

    Understanding the relative importance of dispersal limitation and environmental filtering processes in structuring the beta diversities of subtropical forests in human disturbed landscapes is still limited. Here we used taxonomic (TBD) and phylogenetic (PBD), including terminal PBD (PBDt) and basal PBD (PBDb), beta diversity indices to quantify the taxonomic and phylogenetic turnovers at different depths of evolutionary history in disturbed and undisturbed subtropical forests. Multiple linear regression model and distance-based redundancy analysis were used to disentangle the relative importance of environmental and spatial variables. Environmental variables were significantly correlated with TBD and PBDt metrics. Temperature and precipitation were major environmental drivers of beta diversity patterns, which explained 7–27% of the variance in TBD and PBDt, whereas the spatial variables independently explained less than 1% of the variation for all forests. The relative importance of environmental and spatial variables differed between disturbed and undisturbed forests (e.g., when Bray-Curtis was used as a beta diversity metric, environmental variable had a significant effect on beta diversity for disturbed forests but had no effect on undisturbed forests). We conclude that environmental filtering plays a more important role than geographical limitation and disturbance history in driving taxonomic and terminal phylogenetic beta diversity. PMID:27775021

  4. Disentangling the drivers of taxonomic and phylogenetic beta diversities in disturbed and undisturbed subtropical forests

    NASA Astrophysics Data System (ADS)

    Liu, Jinliang; Qian, Hong; Jin, Yi; Wu, Chuping; Chen, Jianhua; Yu, Shuquan; Wei, Xinliang; Jin, Xiaofeng; Liu, Jiajia; Yu, Mingjian

    2016-10-01

    Understanding the relative importance of dispersal limitation and environmental filtering processes in structuring the beta diversities of subtropical forests in human disturbed landscapes is still limited. Here we used taxonomic (TBD) and phylogenetic (PBD), including terminal PBD (PBDt) and basal PBD (PBDb), beta diversity indices to quantify the taxonomic and phylogenetic turnovers at different depths of evolutionary history in disturbed and undisturbed subtropical forests. Multiple linear regression model and distance-based redundancy analysis were used to disentangle the relative importance of environmental and spatial variables. Environmental variables were significantly correlated with TBD and PBDt metrics. Temperature and precipitation were major environmental drivers of beta diversity patterns, which explained 7–27% of the variance in TBD and PBDt, whereas the spatial variables independently explained less than 1% of the variation for all forests. The relative importance of environmental and spatial variables differed between disturbed and undisturbed forests (e.g., when Bray-Curtis was used as a beta diversity metric, environmental variable had a significant effect on beta diversity for disturbed forests but had no effect on undisturbed forests). We conclude that environmental filtering plays a more important role than geographical limitation and disturbance history in driving taxonomic and terminal phylogenetic beta diversity.

  5. Production of alkaline cellulase by fungi isolated from an undisturbed rain forest of peru.

    PubMed

    Vega, Karin; Villena, Gretty K; Sarmiento, Victor H; Ludeña, Yvette; Vera, Nadia; Gutiérrez-Correa, Marcel

    2012-01-01

    Alkaline cellulase producing fungi were isolated from soils of an undisturbed rain forest of Peru. The soil dilution plate method was used for the enumeration and isolation of fast growing cellulolytic fungi on an enriched selective medium. Eleven out of 50 different morphological colonies were finally selected by using the plate clearing assay with CMC as substrate at different pH values. All 11 strains produced cellulases in liquid culture with activities at alkaline pH values without an apparent decrease of them indicating that they are true alkaline cellulase producers. Aspergillus sp. LM-HP32, Penicillium sp. LM-HP33, and Penicillium sp. LM-HP37 were the best producers of FP cellulase (>3 U mL(-1)) with higher specific productivities (>30 U g(-1) h(-1)). Three strains have been found suitable for developing processes for alkaline cellulase production. Soils from Amazonian rain forests are good sources of industrial fungi with particular characteristics. The results of the present study are of commercial and biological interest. Alkaline cellulases may be used in the polishing and washing of denim processing of the textile industry.

  6. 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

  7. Comparison of vesicular-arbuscular mycorrhizae in plants from disturbed and adjacent undisturbed regions of a coastal salt marsh in Clinton, Connecticut, USA

    NASA Astrophysics Data System (ADS)

    Cooke, John C.; Lefor, Michael W.

    1990-01-01

    Roots of salt marsh plant species Spartina alterniflora, S. patens, Distichlis spicata, and others were examined for the presence of vesicular-arbuscular mycorrhizal (VAM) fungi. Samples were taken from introduced planted material in a salt marsh restoration project and from native material in adjacent marsh areas along the Indian River, Clinton, Connecticut, USA. After ten years the replanted area still has sites devoid of vegetation. The salt marsh plants introduced there were devoid of VAM fungi, while high marsh species from the adjacent undisturbed region showed consistent infection, leading the authors to suggest that VAM fungal infection of planting stocks may be a factor in the success of marsh restoration.

  8. Small scale temporal distribution of radiocesium in undisturbed coniferous forest soil: Radiocesium depth distribution profiles.

    PubMed

    Teramage, Mengistu T; Onda, Yuichi; Kato, Hiroaki

    2016-04-01

    The depth distribution of pre-Fukushima and Fukushima-derived (137)Cs in undisturbed coniferous forest soil was investigated at four sampling dates from nine months to 18 months after the Fukushima nuclear power plant accident. The migration rate and short-term temporal variability among the sampling profiles were evaluated. Taking the time elapsed since the peak deposition of pre-Fukushima (137)Cs and the median depth of the peaks, its downward displacement rates ranged from 0.15 to 0.67 mm yr(-1) with a mean of 0.46 ± 0.25 mm yr(-1). On the other hand, in each examined profile considerable amount of the Fukushima-derived (137)Cs was found in the organic layer (51%-92%). At this moment, the effect of time-distance on the downward distribution of Fukushima-derived (137)Cs seems invisible as its large portion is still found in layers where organic matter is maximal. This indicates that organic matter seems the primary and preferential sorbent of radiocesium that could be associated with the physical blockage of the exchanging sites by organic-rich dusts that act as a buffer against downward propagation of radiocesium, implying radiocesium to be remained in the root zone for considerable time period. As a result, this soil section can be a potential source of radiation dose largely due to high radiocesium concentration coupled with its low density. Generally, such kind of information will be useful to establish a dynamic safety-focused decision support system to ease and assist management actions.

  9. Effects of Bromus tectorum invasion on microbial carbon and nitrogen cycling in two adjacent undisturbed arid grassland communities

    USGS Publications Warehouse

    Schaeffer, Sean M.; Ziegler, Susan E.; Belnap, Jayne; Evans, R.D.

    2012-01-01

    Soil nitrogen (N) is an important component in maintaining ecosystem stability, and the introduction of non-native plants can alter N cycling by changing litter quality and quantity, nutrient uptake patterns, and soil food webs. Our goal was to determine the effects of Bromus tectorum (C3) invasion on soil microbial N cycling in adjacent non-invaded and invaded C3 and C4 native arid grasslands. We monitored resin-extractable N, plant and soil δ13C and δ15N, gross rates of inorganic N mineralization and consumption, and the quantity and isotopic composition of microbial phospholipid biomarkers. In invaded C3 communities, labile soil organic N and gross and net rates of soil N transformations increased, indicating an increase in overall microbial N cycling. In invaded C4 communities labile soil N stayed constant, but gross N flux rates increased. The δ13C of phospholipid biomarkers in invaded C4 communities showed that some portion of the soil bacterial population preferentially decomposed invader C3-derived litter over that from the native C4 species. Invasion in C4 grasslands also significantly decreased the proportion of fungal to bacterial phospholipid biomarkers. Different processes are occurring in response to B. tectorum invasion in each of these two native grasslands that: 1) alter the size of soil N pools, and/or 2) the activity of the microbial community. Both processes provide mechanisms for altering long-term N dynamics in these ecosystems and highlight how multiple mechanisms can lead to similar effects on ecosystem function, which may be important for the construction of future biogeochemical process models.

  10. Snow Distribution Patterns in Clearings and Adjacent Forest

    NASA Astrophysics Data System (ADS)

    Golding, Douglas L.; Swanson, Robert H.

    1986-12-01

    Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8- to 13-ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6-H (height) diameter circular clearings where SWE was 13-45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2-6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.

  11. Trace metal mobility and microbial community structure in tropical soils: examples from adjacent forest and grassland ecosystems

    NASA Astrophysics Data System (ADS)

    Wilson, A. D.; Roberts, J. A.; MacPherson, G. L.; Mauck, B. S.; Stallard, R. F.

    2004-12-01

    Many factors determine the quality and sustainability of a soil environment and changes in land use can impact significantly soil geochemistry and the associated soil microbial communities. Native tropical forests and human-constructed grasslands on Barro Colorado Island provide an excellent setting for comparing changes in soil ecosystems in undisturbed and altered landscapes. The goals of this study were to examine biological, chemical, and mineralogical changes in soil properties as a function of land use changes during the wet and dry seasons. Soil pits were excavated at two study sites, a tropical forest and an adjacent plot that has been converted to grassland, during March 2002 and August 2003. The 1 meter deep pits were sampled at 5 cm intervals and characterized for soil organic matter content, soil moisture, community structure and total lipid biomass of the soil microbial community, mineralogy, and trace metal distribution using a sequential extraction method. Results demonstrate that forested soils exhibit higher organic matter content than grassland soils regardless of soil moisture content. Total lipid biomass of the active soil microbial population decreases with depth in both soils, but is elevated in the forested soil, likely correlating with the organic matter content in this system. Diversity of the soil microbial community, determined by PLFA analysis, decreases sharply at the base of the root zone and general trends in community structure are similar in both soils. XRD analysis of the soils reveal that the weathering profile in the forest has extended to a greater depth, but these differences in the mineralogy profile do not exert significant control on trace element mobility. Vanadium, copper, zinc, and aluminum show strong affinities for the organically bound fraction in both soils.

  12. Pore water chemistry in a disturbed and an undisturbed peat forests in Brunei Darussalam: Nutrient and carbon contents

    NASA Astrophysics Data System (ADS)

    Gandois, L.; Cobb, A.; Abu Salim, K.; Chieng Hei, I.; Lim Biaw Leng, L.; Corlett, R.; Harvey, C.

    2010-12-01

    Tropical peat swamp forests in their natural state are important reservoir of biodiversity, carbon and water. However, they are rapidly vanishing due to agricultural conversion (mainly to oil palms), logging, drainage and fire. Peat swamp forests constitute an important contribution to global and regional biodiversity, providing an habitat to rare and threatened species. They encompass a sequence of forest types from the perimeter to the center of mildely elevated domes, and at our site in Brunei, are host to Shorea Albida trees (Anderson, 1983). They constitute a large terrestrial carbon reservoir (tropical peat soils contain up to 70 Pg C, which accounts for 20% of global peat soil carbon and 2% of the global soil carbon (Hirano et al., 2007)). In tropical peat swamp forests, the most important factors controling organic matter accumulation, as well as the biodiversity and structure of the forest, are hydrology and nutrients availability (Page et al., 1999). Study of pore water in peat swamp forest can provide key information on carbon cycle, including biomass production, organic matter decomposition and leaching of carbon in draining water. However, data on pore water chemistry and nutrient concentrations in pristine tropical peatlands, as well as the effect of forest exploitation are scarce. The study area is located in the Belait district in Brunei Darussalam in Borneo Island. Brunei is perhaps the best of the regional guardians of peat forest systems; potentially irreversible damage to peat forest ecosystems has been widespread elsewhere. Two sites, one pristine dome and a logging concession, are being investigated. In order to assess the chemical status of the peat soil, pore water is sampled at different depth along the dome radius. The chemistry of pore water, including pH, conductivity, dissolved oxygen, concentration of major elements, as well as organic carbon content and properties are analyzed. References: Anderson, 1983. The tropical peat swamp of

  13. Arbuscular mycorrhizae of the palm Astrocaryum mexicanum in disturbed and undisturbed stands of a Mexican tropical forest.

    PubMed

    Núñez-Castillo, O; Alvarez-Sánchez, F J

    2003-10-01

    Tropical forests are dynamic systems with extensive natural disturbance, gaps in the canopy being one of the most important types. Tree and branch fall are often the principal cause of natural disturbance. This research was done on adult individuals of a very abundant palm ( Astrocaryum mexicanum Liebm, Arecaceae), which is found in the understorey of the forest at Los Tuxtlas, Mexico. Percentages of colonization by arbuscular mycorrhizae were determined for individuals selected randomly from plots located both in gaps and under closed canopy. The highest percentages of total colonization, as well as those of hyphae and vesicles, were recorded for gaps. In forest with closed canopy, arbuscules had the highest percentages of colonization; on these sites the palm has been observed to grow less. The higher production of arbuscules may favour nutrient capture in this microenvironment, which is characterized by strong competition.

  14. Can native clonal moso bamboo encroach on adjacent natural forest without human intervention?

    NASA Astrophysics Data System (ADS)

    Bai, Shangbin; Wang, Yixiang; Conant, Richard T.; Zhou, Guomo; Xu, Yong; Wang, Nan; Fang, Feiyan; Chen, Juan

    2016-09-01

    Native species are generally thought not to encroach on adjacent natural forest without human intervention. However, the phenomenon that native moso bamboo may encroach on surrounding natural forests by itself occurred in China. To certificate this encroaching process, we employed the transition front approach to monitor the native moso bamboo population dynamics in native Chinese fir and evergreen broadleaved forest bordering moso bamboo forest in Tianmu Mountain Nature Reserve during the period between 2005 and 2014. The results showed that the bamboo front moved toward the Chinese fir/evergreen broadleaved stand with the new bamboo produced yearly. Moso bamboo encroached at a rate of 1.28 m yr‑1 in Chinese fir forest and 1.04 m yr‑1 in evergreen broadleaved forest, and produced 533/437 new culms hm‑2 yr‑1 in the encroaching natural Chinese fir/evergreen broadleaved forest. Moso bamboo coverage was increasing while adjacent natural forest area decreasing continuously. These results indicate that native moso bamboo was encroaching adjacent natural forest gradually without human intervention. It should be considered to try to create a management regime that humans could selectively remove culms to decrease encroachment.

  15. Can native clonal moso bamboo encroach on adjacent natural forest without human intervention?

    PubMed

    Bai, Shangbin; Wang, Yixiang; Conant, Richard T; Zhou, Guomo; Xu, Yong; Wang, Nan; Fang, Feiyan; Chen, Juan

    2016-09-07

    Native species are generally thought not to encroach on adjacent natural forest without human intervention. However, the phenomenon that native moso bamboo may encroach on surrounding natural forests by itself occurred in China. To certificate this encroaching process, we employed the transition front approach to monitor the native moso bamboo population dynamics in native Chinese fir and evergreen broadleaved forest bordering moso bamboo forest in Tianmu Mountain Nature Reserve during the period between 2005 and 2014. The results showed that the bamboo front moved toward the Chinese fir/evergreen broadleaved stand with the new bamboo produced yearly. Moso bamboo encroached at a rate of 1.28 m yr(-1) in Chinese fir forest and 1.04 m yr(-1) in evergreen broadleaved forest, and produced 533/437 new culms hm(-2) yr(-1) in the encroaching natural Chinese fir/evergreen broadleaved forest. Moso bamboo coverage was increasing while adjacent natural forest area decreasing continuously. These results indicate that native moso bamboo was encroaching adjacent natural forest gradually without human intervention. It should be considered to try to create a management regime that humans could selectively remove culms to decrease encroachment.

  16. Can native clonal moso bamboo encroach on adjacent natural forest without human intervention?

    PubMed Central

    Bai, Shangbin; Wang, Yixiang; Conant, Richard T.; Zhou, Guomo; Xu, Yong; Wang, Nan; Fang, Feiyan; Chen, Juan

    2016-01-01

    Native species are generally thought not to encroach on adjacent natural forest without human intervention. However, the phenomenon that native moso bamboo may encroach on surrounding natural forests by itself occurred in China. To certificate this encroaching process, we employed the transition front approach to monitor the native moso bamboo population dynamics in native Chinese fir and evergreen broadleaved forest bordering moso bamboo forest in Tianmu Mountain Nature Reserve during the period between 2005 and 2014. The results showed that the bamboo front moved toward the Chinese fir/evergreen broadleaved stand with the new bamboo produced yearly. Moso bamboo encroached at a rate of 1.28 m yr−1 in Chinese fir forest and 1.04 m yr−1 in evergreen broadleaved forest, and produced 533/437 new culms hm−2 yr−1 in the encroaching natural Chinese fir/evergreen broadleaved forest. Moso bamboo coverage was increasing while adjacent natural forest area decreasing continuously. These results indicate that native moso bamboo was encroaching adjacent natural forest gradually without human intervention. It should be considered to try to create a management regime that humans could selectively remove culms to decrease encroachment. PMID:27600881

  17. Turbines and terrestrial vertebrates: variation in tortoise survivorship between a wind energy facility and an adjacent undisturbed wildland area in the desert southwest (USA)

    USGS Publications Warehouse

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin J.; Arundel, Terry; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David F.; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-01-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18 year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility scale wind energy on long-lived terrestrial vertebrates.

  18. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA)

    NASA Astrophysics Data System (ADS)

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin; Arundel, Terence R.; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises ( Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  19. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA).

    PubMed

    Agha, Mickey; Lovich, Jeffrey E; Ennen, Joshua R; Augustine, Benjamin; Arundel, Terence R; Murphy, Mason O; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V; Price, Steven J

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  20. The Large-Scale Morphology and Vadose Zone Dynamics of an Undisturbed Tropical Peat Forest in Brunei Darussalam

    NASA Astrophysics Data System (ADS)

    Harvey, C. F.; Cobb, A.; Hoyt, A.; Gandois, L.; Kamariah, A.; Yussof, M.; Jalil, J.; Ali Ahmad, J.

    2013-12-01

    We combine groundwater flow models with hydrologic, flux-chamber, and LIDAR data to study the coupled hydrologic and ecological processes that shape tropical peatlands. We apply this framework to explain the hydrologic behavior and morphology of one of the few remaining primary tropical peat forests, a region on the Mendaram River in the Belait district of Brunei Darussalam. The thickness of the vadose zone remains remarkably uniform across the peatland even as the water table responds to rainstorms, evapotranspiration and discharge to the rivers. Time series from piezometers at different locations all show similar rapid jumps in the watertable during rainstorms, followed initially by quick recessions that are nearly identical across locations, then a slow decline consistent with evapotranspiration as the water table sinks deeper into the peat. The uniform, but transient, thickness of the vadose zone indicates that: (1) Peat oxidation is uniform across the landscape because the same thickness of peat is exposed to the atmosphere; (2) Rainfall infiltrates uniformly until, in exceptional storms, the entire landscape becomes saturated, and; (3) Because the watertable drops and rises uniformly across the region, conservation of water requires that the divergence of pore water flux is also uniform across the domain. This strikingly homogenous hydrologic behavior implies that the topographic curvature of the peatland is described by a uniform Laplacian value. We derive an expression for this uniform Laplacian value as a function of the rainfall statistics and the transmissivity of the peat. Finally, we confirm the predicted topographic Laplacian using airborne LIDAR data gathered across the domain.

  1. Isotopic study of mercury sources and transfer between a freshwater lake and adjacent forest food web.

    PubMed

    Kwon, Sae Yun; Blum, Joel D; Nadelhoffer, Knute J; Timothy Dvonch, J; Tsui, Martin Tsz-Ki

    2015-11-01

    Studies of monomethylmercury (MMHg) sources and biogeochemical pathways have been extensive in aquatic ecosystems, but limited in forest ecosystems. Increasing evidence suggests that there is significant mercury (Hg) exchange between aquatic and forest ecosystems. We use Hg stable isotope ratios (δ(202)Hg and Δ(199)Hg) to investigate the relative importance of MMHg sources and assess Hg transfer pathways between Douglas Lake and adjacent forests located at the University of Michigan Biological Station, USA. We characterize Hg isotopic compositions of basal resources and use linear regression of % MMHg versus δ(202)Hg and Δ(199)Hg to estimate Hg isotope values for inorganic mercury (IHg) and MMHg in the aquatic and adjacent forest food webs. In the aquatic ecosystem, we found that lake sediment represents a mixture of IHg pools deposited via watershed runoff and precipitation. The δ(202)Hg and Δ(199)Hg values estimated for IHg are consistent with other studies that measured forest floor in temperate forests. The Δ(199)Hg value estimated for MMHg in the aquatic food web indicates that MMHg is subjected to ~20% photochemical degradation prior to bioaccumulation. In the forest ecosystem, we found a significant negative relationship between total Hg and δ(202)Hg and Δ(199)Hg of soil collected at multiple distances from the lakeshore and lake sediment. This suggests that IHg input from watershed runoff provides an important Hg transfer pathway between the forest and aquatic ecosystems. We measured Δ(199)Hg values for high trophic level insects and compared these insects at multiple distances perpendicular to the lake shoreline. The Δ(199)Hg values correspond to the % canopy cover suggesting that forest MMHg is subjected to varying extents of photochemical degradation and the extent may be controlled by sunlight. Our study demonstrates that the use of Hg isotopes adds important new insight into the relative importance of MMHg sources and complex Hg transfer

  2. 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.

  3. 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.

  4. Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry.

    PubMed

    Klein, Alexandra-Maria; Steffan-Dewenter, Ingolf; Tscharntke, Teja

    2006-03-01

    1. Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2. In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0-1415 m), light intensity (37.5-899.6 W/m(-2)) and number of vascular plant species (7-40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3. A total of 13,617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4. The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey.

  5. Agricultural Intensification Exacerbates Spillover Effects on Soil Biogeochemistry in Adjacent Forest Remnants

    PubMed Central

    Didham, Raphael K.; Barker, Gary M.; Bartlam, Scott; Deakin, Elizabeth L.; Denmead, Lisa H.; Fisk, Louise M.; Peters, Jennifer M. R.; Tylianakis, Jason M.; Wright, Hannah R.; Schipper, Louis A.

    2015-01-01

    Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could ‘spare’ further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables), and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ15N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U) increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone, even in fenced

  6. Agricultural intensification exacerbates spillover effects on soil biogeochemistry in adjacent forest remnants.

    PubMed

    Didham, Raphael K; Barker, Gary M; Bartlam, Scott; Deakin, Elizabeth L; Denmead, Lisa H; Fisk, Louise M; Peters, Jennifer M R; Tylianakis, Jason M; Wright, Hannah R; Schipper, Louis A

    2015-01-01

    Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could 'spare' further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables), and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ15N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U) increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone, even in fenced

  7. Soil-atmosphere exchange of methane in adjacent cultivated and floodplain forest soils

    NASA Astrophysics Data System (ADS)

    Burke, Roger A.; Meyer, Judith L.; Cruse, Jennifer M.; Birkhead, Karen M.; Paul, Michael J.

    1999-04-01

    The soil-atmosphere exchange of methane was measured in adjacent cultivated (corn) and forest (upper floodplain, mixed hardwood) habitats of the southeastern U.S. piedmont for a period of 3 years using closed chambers. We have evaluated the effect of the following factors on soil-atmosphere methane exchange: (1) interannual variability of climatic conditions, (2) landscape position (i.e., river levee versus terrace), and (3) disturbance ranging from intense (cultivation) through moderate (approximately annual flooding events that last from weeks to months) to subtle (approximately annual flooding of a few days duration). We found that mean methane consumption in the cultivated and forested terrace sites was <0.3 mg CH4 m-2 d-1, whereas the mean consumption rate in forested levee sites was about 1.4 mg CH4 m-2 d-1 over the course of the 3 years. Moisture levels in the upper soil (0-5 cm) appear to exert little control of methane exchange in any of the habitats. We observed little seasonal variation in methane flux in the levee sites, in contrast to results observed by others in higher-latitude and tropical forests. Our results suggest that very subtle differences in landscape position and disturbance impact the strength of the soil methane sink. We cannot conclude that agricultural development destroyed the methane sink capacity of these floodplain terrace soils because it was probably already quite low due to periodic disturbance by flooding. Limited measurements of nitrogen cycling suggest that methane flux differences observed among the different habitats are not obviously related to differences in N mineralization or nitrification as in other ecosystems.

  8. Denitrification in sediments from the hyporheic zone adjacent to a small forested stream

    USGS Publications Warehouse

    Duff, J.H.; Triska, F.J.

    1990-01-01

    Denitrifying potentials increased with increasing distance from the stream channel. Dissolved oxygen was 100% of the concentration expected in equilibrium with the atmosphere in water obtained from monitoring wells immediately adjacent to the stream but was as low as 7% of the expected value in water 11.4 m inland. Both nitrate and dissolved organic carbon decreased over summer in wells at the base of the alder-forested slope. A 48-h injection of nitrate-amended stream water into hyporheic water 8.4 m inland stimulated nitrous oxide production in the presence of acetylene. Nitrous oxide was generated as nitrate and acetylene were co-transported to a well 13 m down-gradient. Acetylene-block experiments coupled with the chemistry data suggest that denitrification can modify the chemistry of water during passage through the hyporheic zone. -from Authors

  9. Floristic study of Ghasemloo (Shohada) Valley Forest reserve and adjacent area.

    PubMed

    Malekmohammadi, L; Mahmoudzadeh, A; Hassanzadeh, A

    2007-05-15

    In this survey flora of protected region of Ghasemloo valley Forest reserve and adjacent areas has been studied. The study area includes about 577 ha and is located at south of Urmia. The method which used for plant collection is the same as regional floristic studies. Collected plants were recognized and determined as families, genera and species by using of indispensable references. Alphabetical list of taxa in this region was provided on the base of families, genera and species. The life form of plant species was determined by using of Raunckier's method and chorotype of plant species was determined by indispensable references. In this research 50 family, 165 genera and 204 species were identified. The largest plant family is Compositae with 21 genera and 26 species and the largest genera is Astragalus from Papilionaceae family with 6 species. The main biological forms respectively are: Therophytes and hemichryptophytes. The most extended chorotype with 61.28% is related to Irano-Turanian.

  10. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans

    NASA Astrophysics Data System (ADS)

    Jiménez-Muñoz, Juan C.; Mattar, Cristian; Sobrino, José A.; Malhi, Yadvinder

    2015-05-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download.

  11. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans.

    PubMed

    Jiménez-Muñoz, Juan C; Mattar, Cristian; Sobrino, José A; Malhi, Yadvinder

    2015-01-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download.

  12. A database for the monitoring of thermal anomalies over the Amazon forest and adjacent intertropical oceans

    PubMed Central

    Jiménez-Muñoz, Juan C.; Mattar, Cristian; Sobrino, José A.; Malhi, Yadvinder

    2015-01-01

    Advances in information technologies and accessibility to climate and satellite data in recent years have favored the development of web-based tools with user-friendly interfaces in order to facilitate the dissemination of geo/biophysical products. These products are useful for the analysis of the impact of global warming over different biomes. In particular, the study of the Amazon forest responses to drought have recently received attention by the scientific community due to the occurrence of two extreme droughts and sustained warming over the last decade. Thermal Amazoni@ is a web-based platform for the visualization and download of surface thermal anomalies products over the Amazon forest and adjacent intertropical oceans using Google Earth as a baseline graphical interface (http://ipl.uv.es/thamazon/web). This platform is currently operational at the servers of the University of Valencia (Spain), and it includes both satellite (MODIS) and climatic (ERA-Interim) datasets. Thermal Amazoni@ is composed of the viewer system and the web and ftp sites with ancillary information and access to product download. PMID:26029379

  13. Galling arthropod diversity in adjacent swamp forests and restinga vegetation in Rio Grande do Sul, Brazil.

    PubMed

    Mendonça, Milton De S; Piccardi, Hosana M F; Jahnke, Simone M; Dalbem, Ricardo V

    2010-01-01

    Galling arthropods create plant structures inside which they find shelter. Factors acting on galler diversity are still being discussed, with this fauna considered more diverse in xeric than mesic environments (higrothermic stress hypothesis, HSH), and also in more plant diverse sites. Here we compare galler abundance (N), equitability (E), species richness (S) and composition between adjacent restinga (xeric) and swamp forests (mesic) in Parque Estadual de Itapeva (29°21' S, 49°45' W), Rio Grande do Sul, southern Brazil. Five trails, two in swamp forest and three in restingas, were sampled four times each (January/December 2005). After an effort of 60h/person, 621 galled plant individuals belonging to 104 gall morphotypes were recorded. This suggests a high galler diversity for the Park, comparable to the richest places known. No differences were found for N, E or S between restingas and swamp forests. However, faunal composition differs significantly between the vegetation types. The dominant (most abundant) species are different in either vegetation type, and are rare or absent on the other vegetation type. Such species composition analysis is still largely ignored for gallers, and stresses the fact that the HSH cannot explain this pattern, since the latter is based on preferences by the ovipositing galler for xeric sites instead of mesic ones. The two habitats differ in microclimate, but species richness, as would be predicted by the HSH, does not differ. This small scale pattern can perhaps be attributed to biogeographic processes on larger scales, as suggested by the resource synchronisation hypothesis.

  14. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    NASA Astrophysics Data System (ADS)

    Morton, Douglas M.; Alvarez, Rachel M.; Ruppert, Kelly R.; Goforth, Brett

    2008-04-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5 km/h to about 90 km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the channel

  15. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    USGS Publications Warehouse

    Morton, D.M.; Alvarez, R.M.; Ruppert, K.R.; Goforth, B.

    2008-01-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5??km/h to about 90??km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the

  16. Spillover from adjacent crop and forest habitats shapes carabid beetle assemblages in fragmented semi-natural grasslands.

    PubMed

    Schneider, Gudrun; Krauss, Jochen; Boetzl, Fabian A; Fritze, Michael-Andreas; Steffan-Dewenter, Ingolf

    2016-12-01

    Semi-natural grasslands in Europe are insect biodiversity hotspots and important source habitats delivering ecosystem services to adjacent agricultural land by species spillover. However, this spillover might also occur in the opposite direction, affecting the diversity of semi-natural grasslands. This opposite spillover has got little attention in scientific literature even though generalist species penetrating into the grasslands can affect local biotic interactions, community composition and the conservation value of grassland habitats. In this study, we examined spillover effects from two different adjacent habitat types on carabid beetle assemblages in 20 semi-natural calcareous grasslands. The grasslands were either adjacent to a cereal crop field or to a coniferous forest. We found distinct differences in carabid beetle assemblages in calcareous grasslands depending on adjacent habitat type. Species richness and activity density were higher, but the evenness was lower in calcareous grasslands adjacent to crop fields compared with calcareous grasslands adjacent to coniferous forests. Further, we found a strong spillover of carabid beetles from adjacent crop fields after crop harvest, which may result in transiently increased predation pressure and resource competition in calcareous grasslands. Our results highlight that species composition, diversity and presumably ecosystem functions within semi-natural habitats are affected by the type and management of surrounding habitats. This needs to be considered by nature conservation measures, which aim to protect the unique insect communities of semi-natural European grasslands.

  17. Seasonal trends in environmental tritium concentrations in a small forest adjacent to a radioactive waste storage area

    SciTech Connect

    Amano, Hikaru ); Garten, C.T. Jr. )

    1991-01-01

    Tritium (HTO) concentrations were studied for an entire year in a floodplain forest adjacent to a low-level radioactive solid waste storage area (SWSA No. 5) at Oak Ridge National Laboratory (ORNL) near Oak Ridge, Tennessee, USA. Tritium in soil was the principal source of HTO to the deciduous forest. Evaporation from the surface soil along with transpiration from trees leaves both contributed to HTO in the forest atmosphere. During the growing season, transpiration was the principal contributor of HTO to the forest atmosphere, while during the dormant season, the main source of atmospheric HTO was evaporation from the surface soil. Seasonal changes and the characteristics of vegetation will influence the relative importance of evaporation and transpiration as sources of atmospheric HTO near the ground in temperate deciduous forests. 8 refs., 9 figs.

  18. Seasonal trends in environmental tritium concentrations in a small forest adjacent to a radioactive waste storage area

    SciTech Connect

    Amano, H. ); Garten, C.T. Jr. . Environmental Sciences Div.)

    1992-03-01

    Tritium (HTO) concentrations were studied for an entire year in a floodplain forest adjacent to a low-level radioactive solid waste storage areas (SWSA No. 5) at Oak Ridge National Laboratory (ORNL) near Oak Ridge, Tennessee, USA. Tritium in soil was the principal source of HTO to the deciduous forest. Evaporation from the surface soil along with transpiration from tree leaves both contributed to HTO in the forest atmosphere. During the growing season, transpiration was the principal contributor of HTO to the forest atmosphere, while during he dormant season, the main source of atmospheric HTO was evaporation from the surface soil. This paper discovers seasonal changes and the characteristics of vegetation which will influence the relative importance of evaporation and transpiration as sources of atmospheric HTO near the ground in temperate deciduous forests.

  19. Forest adjacent households' voices on their perceptions and adaptation strategies to climate change in Kilombero District, Tanzania.

    PubMed

    Balama, Chelestino; Augustino, Suzana; Eriksen, Siri; Makonda, Fortunatus B S

    2016-01-01

    Climate change is a global and local challenge to both sustainable livelihoods and economic development. Tanzania as other countries of the world has been affected. Several studies have been conducted on farmers' perceptions and adaptation to climate change in the country, but little attention has been devoted to forest adjacent households in humid areas. This study assessed this gap through assessing forest adjacent households' voices on perceptions and adaptation strategies to climate change in Kilombero District, Tanzania. Data collection involved key informant interviews, focus group discussions and household questionnaires. Results showed that the majority of households perceived changed climate in terms of temperature increase, unpredictable rainfall, frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources and emergence of new pests and diseases. The perceived change in climate has impacted agriculture productivity as the main livelihood source. Different coping and adaptation strategies are employed. These are; crop diversification, changing cropping calendar, adopting modern farming technologies, and increasing reliance on non-timber forest products. These strategies were positively and significantly influenced by socio-economic factors including household size, residence period, land ownership and household income. The study concludes that, there are changes in climatic conditions; and to respond to these climatic changes, forest adjacent households have developed numerous coping and adaptation strategies, which were positively and significantly influenced by some socio-economic factors. The study calls for actual implementation of local climate change policies and strategies in order to enhance adaptive capacity at household level.

  20. Leucaena leucocephala and adjacent native limestone forest habitats contrast in soil properties on Tinian Island.

    PubMed

    Marler, Thomas E; Dongol, Nirmala; Cruz, Gil N

    2016-01-01

    An ex situ germplasm collection of the endangered Cycas micronesica was established in a transition zone between biodiverse native forest and mature stands of the invasive species Leucaena leucocephala. Soil chemical properties were determined for the 2 tree cover types to inform management decisions. Total carbon, total nitrogen, calcium, and net ammonification were greater in native forest cover than in L. leucocephala patches. Net nitrification and net mineralization were greater under L. leucocephala cover. Trace metals also differed between the 2 forest cover types, with chromium, cobalt, and nickel accumulating to greater concentration under L. leucocephala cover and zinc accumulating to greater concentration under native forest cover. The results indicated that L. leucocephala cover generated substantial changes in soil chemical properties when compared with native forest tree cover, illuminating one means by which understory vegetation may be affected by changes in invasive tree cover.

  1. Leucaena leucocephala and adjacent native limestone forest habitats contrast in soil properties on Tinian Island

    PubMed Central

    Marler, Thomas E.; Dongol, Nirmala; Cruz, Gil N.

    2016-01-01

    ABSTRACT An ex situ germplasm collection of the endangered Cycas micronesica was established in a transition zone between biodiverse native forest and mature stands of the invasive species Leucaena leucocephala. Soil chemical properties were determined for the 2 tree cover types to inform management decisions. Total carbon, total nitrogen, calcium, and net ammonification were greater in native forest cover than in L. leucocephala patches. Net nitrification and net mineralization were greater under L. leucocephala cover. Trace metals also differed between the 2 forest cover types, with chromium, cobalt, and nickel accumulating to greater concentration under L. leucocephala cover and zinc accumulating to greater concentration under native forest cover. The results indicated that L. leucocephala cover generated substantial changes in soil chemical properties when compared with native forest tree cover, illuminating one means by which understory vegetation may be affected by changes in invasive tree cover. PMID:27829978

  2. COLLECTION OF UNDISTURBED SURFACE SEDIMENTS

    EPA Science Inventory

    The National Resource Council identified the need for a capability to collect undisturbed surface sediments. Surface sediments are an important source for most exposure of fish to polychlorinated biphenyls via direct uptake from water in contact with sediments. An innovative sedi...

  3. Mites associated with sugarcane crop and with native trees from adjacent Atlantic forest fragment in Brazil.

    PubMed

    Duarte, Mércia E; Navia, Denise; dos Santos, Lucas R; Rideiqui, Pedro J S; Silva, Edmilson S

    2015-08-01

    In some Brazilian regions the Atlantic forest biome is currently restrict to fragments occurring amid monocultures, as sugarcane crops in the Northeast region. Important influence of forest remnants over mite fauna of permanent crops have been showed, however it has been poorly explored on annual crops. The first step for understanding ecological relationship in an agricultural systems is known its composition. The objective of this study was to investigate the plant-inhabiting mite fauna associated with sugarcane crop (Saccharum officinarum L.) (Poaceae) and caboatã (Cupania oblongifolia Mart.) (Sapindaceae) trees in the state of Alagoas, Brazil. Sugarcane stalks and sugarcane and caboatã apical, middle and basal leaves were sampled. A total of 2565 mites were collected from sugarcane and classified into seven families of Trombidiformes and Mesostigmata orders, with most individuals belonging to the Eriophyidae, Tetranychidae and Tarsonemidae families. Among predatory mites, the Phytoseiidae were the most common. A total of 1878 mites were found on C. oblongifolia and classified into 13 families of Trombidiformes and Mesostigmata orders. The most abundant phytophagous mite family on caboatã was also Eriophyidae. In contrast to sugarcane, Ascidae was the most common predatory mite family observed in caboatã. No phytophagous species were common to both sugarcane and C. oblongifolia. However two predatory mites were shared between host plants. Although mites associated with only one native species in the forest fragment were evaluated in this study, our preliminary results suggest Atlantic forest native vegetation can present an important role in the sugarcane agricultural system as a source of natural enemies.

  4. Roads in northern hardwood forests affect adjacent plant communities and soil chemistry in proportion to the maintained roadside area.

    PubMed

    Neher, Deborah A; Asmussen, David; Lovell, Sarah Taylor

    2013-04-01

    The spatial extent of the transported materials from three road types was studied in forest soil and vegetative communities in Vermont. Hypotheses were two-fold: 1) soil chemical concentrations above background environment would reflect traffic volume and road type (highway>2-lane paved>gravel), and 2) plant communities close to the road and near roads with greater traffic will be disturbance-tolerant and adept at colonization. Soil samples were gathered from 12 randomly identified transects for each of three road types classified as "highway," "two-lane paved," and "gravel." Using GIS mapping, transects were constructed perpendicular to the road, and samples were gathered at the shoulder, ditch, backslope, 10 m from the edge of the forest, and 50 m from road center. Sample locations were analyzed for a suite of soil elements and parameters, as well as percent area coverage by plant species. The main effects from roads depended on the construction modifications required for a roadway (i.e., vegetation clearing and topography modification). The cleared area defined the type of plant community and the distance that road pollutants travel. Secondarily, road presence affected soil chemistry. Metal concentrations (e.g., Pb, Cd, Cu, and Zn) correlated positively with road type. Proximity to all road types made the soils more alkaline (pH 7.7) relative to the acidic soil of the adjacent native forest (pH 5.6). Roadside microtopography had marked effects on the composition of plant communities based on the direction of water flow. Ditch areas supported wetland plant species, greater soil moisture and sulfur content, while plant communities closer to the road were characteristic of drier upland zones. The area beyond the edge of the forest did not appear to be affected chemically or physically by any of the road types, possibly due to the dense vegetation that typically develops outside of the managed right-of-way.

  5. Influence of disturbance on carbon exchange in a permafrost collapse and adjacent burned forest

    USGS Publications Warehouse

    Myers-Smith, I. H.; McGuire, A.D.; Harden, J.W.; Chapin, F. S.

    2007-01-01

    We measured CO2 and CH4 exchange from the center of a Sphagnum-dominated permafrost collapse, through an aquatic most, and into a recently burned black spruce forest on the Tanana River floodplain in interior Alaska. In the anomalously dry growing season of 2004, both the collapse and the surrounding burned area were net sink, s for CO2, with a mean daytime net ecosystem exchange of -1.4 ??mol CO2 m-2 s-1, while the moat was a CH4 source with a mean flux of 0.013 ??mol CH4 m-2 s-1. Regression analyses identified temperature as the dominant factor affecting intragrowing season variation in CO2 exchange and soil moisture as the primary control influencing CH4 emissions. CH4 emissions during the wettest portion of the growing season were four times higher than during the driest periods. If temperatures continue to warm, peatlahd vegetation will likely expand with permafrost degradation, resulting in greater carbon accumulation and methane emissions for the landscape as a whole. Copyright 2007 by the American Geophysical Union.

  6. The study of the undiscovered mineral resources of the Tongass National Forest and adjacent lands, Southeastern Alaska

    USGS Publications Warehouse

    Brew, D.A.; Drew, L.J.; Ludington, S.D.

    1992-01-01

    The quantitative probabilistic assessment of the undiscovered mineral resources of the 17.1-million-acre Tongass National Forest (the largest in the United States) and its adjacent lands is a nonaggregated, mineral-resource-tract-oriented assessment designed for land-planning purposes. As such, it includes the renewed use of gross-in-place values (GIPV's) in dollars of the estimated amounts of metal contained in the undiscovered resources as a measure for land-use planning. Southeastern Alaska is geologically complex and contains a wide variety of known mineral deposits, some of which have produced important amounts of metals during the past 100 years. Regional geological, economic geological, geochemical, geophysical, and mineral exploration history information for the region was integrated to define 124 tracts likely to contain undiscovered mineral resources. Some tracts were judged to contain more than one type of mineral deposit. Each type of deposit may contain one or more metallic elements of economic interest. For tracts where information was sufficient, the minimum number of as-yet-undiscovered deposits of each type was estimated at probability levels of 0.95, 0.90, 0.50, 0.10, and 0.05. The undiscovered mineral resources of the individual tracts were estimated using the U.S. Geological Survey's MARK3 mineral-resource endowment simulator; those estimates were used to calculate GIPV's for the individual tracts. Those GIPV's were aggregated to estimate the value of the undiscovered mineral resources of southeastern Alaska. The aggregated GIPV of the estimates is $40.9 billion. Analysis of this study indicates that (1) there is only a crude positive correlation between the size of individual tracts and their mean GIPV's: and (2) the number of mineral-deposit types in a tract does not dominate the GIPV's of the tracts, but the inferred presence of synorogenic-synvolcanic nickel-copper, porphyry copper skarn-related, iron skarn, and porphyry copper

  7. Impacts of Sedimentation from Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds of the Allegheny National Forest of Northwestern Pennsylvania

    SciTech Connect

    Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

    2011-01-01

    Fritz, Kelley'*, Steven Harris', Harry Edenborn2, and James Sams2. 'Clarion University of Pennsylvania, Clarion, PA 16214, 2National Energy Technology Laboratory, U.S. Dept. Energy, Pittsburgh, PA 15236. Impacts a/Sedimentation/rom Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds a/the Allegheny National Forest a/Northwestern Pennsylvania - The Allegheny National Forest (ANF), located in northwestern Pennsy Ivania, is a multiuse forest combining commercial development with recreational and conservation activities. As such, portions of the ANF have been heavily logged and are now the subject of widespread oil and gas development. This rapid increase in oil and gas development has led to concerns about sediment runoff from the dirt and gravel roads associated with development and the potential impact on the aquatic biota of the receiving streams. We examined and compared the benthic macroinvertebrate communities in two adjacent watersheds of similar size and topography in the ANF; the Hedgehog Run watershed has no oil and gas development, while the adjacent Grunder Run watershed has extensive oil and gas development. In Hedgehog and Grunder Run, we collected monthly kicknet samples from riffles and glides at two sites from April to October 2010. At the same intervals, we measured standard water quality parameters, including conductivity and turbidity. Preliminary results have indicated much higher turbidity in Grunder Run, but little difference in the diversity and abundance of benthic macro invertebrates inhabiting the two streams.

  8. Above-ground sulfur cycling in adjacent coniferous and deciduous forest and watershed sulfur retention in the Georgia Piedmont, U.S.A.

    USGS Publications Warehouse

    Cappellato, R.; Peters, N.E.; Meyers, T.P.

    1998-01-01

    Atmospheric deposition and above-ground cycling of sulfur (S) were evaluated in adjacent deciduous and coniferous forests at the Panola Mountain Research Watershed (PMRW), Georgia U.S.A. Total atmospheric S deposition (wet plus dry) was 12.9 and 12.7 kg ha-1 yr-1 for the deciduous and coniferous forests, respectively, from October 1987 through November 1989. Dry deposition contributes more than 40% to the total atmospheric S deposition, and SO2 is the major source (~55%) of total dry S deposition. Dry deposition to these canopies is similar to regional estimates suggesting that 60-km proximity to emission sources does not noticeably impact dry deposition at PMRW. Below-canopy S fluxes (throughfall plus stemflow) in each forest are 37% higher annually in the deciduous forest than in the coniferous forest. An excess in below-canopy S flux in the deciduous forest is attributed to leaching and higher dry deposition than in the coniferous forest. Total S deposition to the forest floor by throughfall, stemflow and litterfall was 2.4 and 2.8 times higher in the deciduous and coniferous forests, respectively, than annual S growth requirement for foliage and wood. Although A deposition exceeds growth requirement, more than 95% of the total atmospheric S deposition was retained by the watershed in 1988 and 1989. The S retention at PMRW is primarily due to SO2+4 adsorption by iron oxides and hydroxides in watershed soils. The S content in while oak and loblolly pine boles have increased more than 200% in the last 20 yr, possibly reflecting increases in emissions.

  9. Comparative resistance and resilience of soil microbial communities and enzyme activities in adjacent native forest and agricultural soils.

    PubMed

    Chaer, Guilherme; Fernandes, Marcelo; Myrold, David; Bottomley, Peter

    2009-08-01

    Degradation of soil properties following deforestation and long-term soil cultivation may lead to decreases in soil microbial diversity and functional stability. In this study, we investigated the differences in the stability (resistance and resilience) of microbial community composition and enzyme activities in adjacent soils under either native tropical forest (FST) or in agricultural cropping use for 14 years (AGR). Mineral soil samples (0 to 5 cm) from both areas were incubated at 40 degrees C, 50 degrees C, 60 degrees C, or 70 degrees C for 15 min in order to successively reduce the microbial biomass. Three and 30 days after the heat shocks, fluorescein diacetate (FDA) hydrolysis, cellulase and laccase activities, and phospholipid-derived fatty acids-based microbial community composition were measured. Microbial biomass was reduced up to 25% in both soils 3 days after the heat shocks. The higher initial values of microbial biomass, enzyme activity, total and particulate soil organic carbon, and aggregate stability in the FST soil coincided with higher enzymatic stability after heat shocks. FDA hydrolysis activity was less affected (more resistance) and cellulase and laccase activities recovered more rapidly (more resilience) in the FST soil relative to the AGR counterpart. In the AGR soil, laccase activity did not show resilience to any heat shock level up to 30 days after the disturbance. Within each soil type, the microbial community composition did not differ between heat shock and control samples at day 3. However, at day 30, FST soil samples treated at 60 degrees C and 70 degrees C contained a microbial community significantly different from the control and with lower biomass regardless of high enzyme resilience. Results of this study show that deforestation followed by long-term cultivation changed microbial community composition and had differential effects on microbial functional stability. Both soils displayed similar resilience to FDA hydrolysis, a

  10. Hooded-Warbler Nesting Success Adjacent to Group-Selection and Clearcut Edges in a Southeastern Bottomland Forest

    SciTech Connect

    Moorman, C.E.; Guynn, D.C., Jr.; Kilgo, J.C.

    2002-01-11

    Location and monitoring of Hooded-Warbler nests in a bottomland forest and examined the effects of edge proximity, edge type and nest-site vegetation on nesting success. Probability of parasitism by Brown-headed cowbirds was higher near clearcut edges and parasitism reduced clutch-size and numbers of fledglings per successful nest. Study was conducted in a primarily forested landscape, so cowbird abundance or negative edge effects may have been low relative to agricultural landscapes in the South.

  11. Fate of Herbicides and Their Degradation Products Entering a Forested Riparian Buffer Following Herbicides Application to an Adjacent Corn Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fate of two herbicides, atrazine and metolachlor, were followed as they entered and moved through a forested riparian wetland located in the mid-Atlantic coastal plain of Maryland. The herbicides were applied as pre-emergent treatments to a 20-ha corn field directly upgradient of the riparian w...

  12. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua and A. suspensa at four sites in Guánica, Puerto Rico; one forest fragment in Ponce, Puerto Rico; in a commercial mango orchard in Guayanilla, PR; and an experimental carambola orcha...

  13. Survey of Lava Tubes in the Former Puna Forest Reserve and on Adjacent State of Hawaii Lands

    SciTech Connect

    McEldowney, H.; Stone, F.D.

    1991-10-01

    This study was initiated after members of the Puna community brought to the attention of the Historic Preservation Office that major lava tube systems extended from the Pahoa area into at least portions of the former Puna Forest Reserve. They were concerned that planned geothermal exploration and development could damage these lava tubes which they said contained extensive evidence of past Hawaiian use including fortifications, shrines, platforms and burials. Geothermal development is currently being planned by Campbell Estate and True Geothermal Energy Company in the southern portion of the former Reserve which has been designated by the State of Hawaii as one of the three Geothermal Sub-Zones in Puna. To demonstrate these claims, two staff members of the Historic Sites Section were shown examples in a lava tube makai of the Campbell Estate boundary. After reviewing the archaeological and historical reports commissioned for geothermal exploration, it was agreed that if these lava tubes did extend inland and continued to contain archaeological sites or burials then the potential of significant sub-surface sites had not been adequately addressed in the Historic Sites Section review process. Most reports acknowledged the possibility of lava tubes in the area and that they could contain burials, but no tube systems were ever identified or explored during any of the field surveys. These surveys primarily assessed the presence or absence of cultural properties that occur on the surface or as deposits within the soil layer. With the assistance of the Division of Water Resource Management (DWRM), the Historic Sites Section agreed to conduct this survey because those community members who came forward requested that this information be handled by a neutral party. They asked that documentation occur in such a manner that it could be kept as confidential as possible while still providing enough information to protect any sites from damage. The survey had three major aims

  14. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico.

    PubMed

    Jenkins, David A; Kendra, Paul E; Van Bloem, Skip; Whitmire, Stefanie; Mizell, Russ; Goenaga, Ricardo

    2013-04-01

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua (Macquart) and Anastrepha suspensa (Loew) in two orchards with hosts of these flies (mango, Mangifera indica L., and carambola, Averrhoa carambola L.), as well as in forest fragments bordering these orchards. Contour maps were constructed to measure population distributions in and around orchards. Our results indicate that Anastrepha populations are focused around host fruit in both space and time, that traps do not draw fruit flies away from hosts, even when placed within 15 m of the host, and that lures continue to function for 6 mo in the field. The contour mapping analyses reveal that populations of fruit flies are focused around ovipositional hosts. Although the trapping system does not have a very long effective sampling range, it is ideal, when used in combination with contour analyses, for assessing fine-scale (on the order of meters) population distributions, including identifying resources around which fly populations are focused or, conversely, assessing the effectiveness of management tools. The results are discussed as they pertain to monitoring and detecting Anastrepha spp. with the McPhail-type trap and ammonium acetate and putrescine baiting system and the dispersal of these flies within Puerto Rico.

  15. Matching in an Undisturbed Natural Human Environment

    PubMed Central

    McDowell, J.J; Caron, Marcia L

    2010-01-01

    Data from the Oregon Youth Study, consisting of the verbal behavior of 210 adolescent boys determined to be at risk for delinquency (targets) and 210 of their friends (peers), were analyzed for their conformance to the complete family of matching theory equations in light of recent findings from the basic science, and using recently developed analytic techniques. Equations of the classic and modern theories of matching were fitted as ensembles to rates and time allocations of the boys' rule-break and normative talk obtained from conversations between pairs of boys. The verbal behavior of each boy in a conversation was presumed to be reinforced by positive social responses from the other boy. Consistent with recent findings from the basic science, the boys' verbal behavior was accurately described by the modern but not the classic theory of matching. These findings also add support to the assertion that basic principles and processes that are known to govern behavior in laboratory experiments also govern human social behavior in undisturbed natural environments. PMID:21119854

  16. Comparison of breeding bird and vegetation communities in primary and secondary forests of Great Smoky Mountains National Park

    USGS Publications Warehouse

    Simons, Theodore R.; Shriner, Susan A.; Farnsworth, George L.

    2006-01-01

    We compared breeding bird communities and vegetation characteristics at paired point locations in primary (undisturbed) and mature secondary forest (70-100 years old) sites in Great Smoky Mountains National Park, USA to understand how sites logged prior to creation of the park compare to undisturbed sites following 70 years of protection from human disturbance. We found that bird and vegetation communities are currently similar, but retain some differences in species composition. Rank abundance curves for primary and secondary forest bird communities showed very similar patterns of species dominance. Species composition was also similar on the two sites which shared 24 of the 25 most frequently recorded species. Nonetheless, comparisons of density estimates derived from distance sampling showed three bird species were more abundant on primary forest sites and that one bird species was significantly more abundant on secondary forest sites. Notably, comparisons based on raw counts (unadjusted for potential differences in detectability) produced somewhat different results. Analyses of vegetation samples for the paired sites also showed relative similarity, but with some differences between primary and secondary forests. Primary forest sites had more large trees (trees greater than 50 cm diameter at breast height) and late successional species. Primary forest sites had a denser tall shrub layer while secondary forest sites had a denser canopy layer. Nonetheless, tree species richness, basal area of live trees and number of standing snags did not differ between primary and secondary forest sites. Results indicate that breeding bird communities on sites within the park that were logged commercially 70 years ago are currently quite similar to bird communities on sites with no history of human disturbance. Similarities between the bird communities on previously disturbed and undisturbed sites in Great Smoky Mountains National Park may exceed those on more fragmented

  17. Reforestation sites show similar and nested AMF communities to an adjacent pristine forest in a tropical mountain area of South Ecuador.

    PubMed

    Haug, Ingeborg; Setaro, Sabrina; Suárez, Juan Pablo

    2013-01-01

    Arbuscular mycorrhizae are important for growth and survival of tropical trees. We studied the community of arbuscular mycorrhizal fungi in a tropical mountain rain forest and in neighbouring reforestation plots in the area of Reserva Biológica San Francisco (South Ecuador). The arbuscular mycorrhizal fungi were analysed with molecular methods sequencing part of the 18 S rDNA. The sequences were classified as Operational Taxonomic Units (OTUs). We found high fungal species richness with OTUs belonging to Glomerales, Diversisporales and Archaeosporales. Despite intensive sampling, the rarefaction curves are still unsaturated for the pristine forest and the reforestation plots. The communities consisted of few frequent and many rare species. No specific interactions are recognizable. The plant individuals are associated with one to ten arbuscular mycorrhizal fungi and mostly with one to four. The fungal compositions associated with single plant individuals show a great variability and variety within one plant species. Planted and naturally occurring plants show high similarities in their fungal communities. Pristine forest and reforestation plots showed similar richness, similar diversity and a significantly nested structure of plant-AMF community. The results indicate that small-scale fragmentation presently found in this area has not destroyed the natural AMF community, at least yet. Thus, the regeneration potential of natural forest vegetation at the tested sites is not inhibited by a lack of appropriate mycobionts.

  18. A technique for cutting brittle undisturbed lateritic soil block samples.

    PubMed

    Galvão, T Cássia de Brito; Drnevich, Vincent P; Schulze, Darrell G

    2003-05-01

    This note describes a technique for cutting undisturbed brittle block samples into smaller specimens for further geotechnical testing. This technique revealed very useful in dealing with collapsible soils, where the sampling is recommended to be done with block soil samples. A further use of this technique as an efficient way for sampling collapsible soils is proposed.

  19. Inter-annual variability in the biosphere-atmosphere exchange of carbon dioxide and water vapor in adjacent pine and hardwood forests: links to drought, disturbance, and seasonality

    NASA Astrophysics Data System (ADS)

    Novick, K. A.; Ward, E. J.; Oishi, A. C.; Stoy, P. C.

    2012-12-01

    Understanding the variation in long-term biosphere-atmosphere fluxes of carbon dioxide and water vapor is necessary to characterize the benefits and services of terrestrial ecosystems, including the highly productive forests of the Southeastern United States. This study quantifies flux variability at inter-annual times scales using eight-year eddy covariance records from two co-located ecosystems in the Duke Forest (North Carolina, USA): a hardwood deciduous forest (HW) and a pine plantation (PP), which together represent the dominant forest types in the region. When averaged across the study period, annual net ecosystem exchange of CO2 (NEE) was similar in PP and HW (NEE = -560 and -520 g C m-2 y-1 in PP and HW, respectively). Variation in annual NEE was high in both ecosystems, but higher in the pine site (CV = 0.38) as compared to the hardwood site (CV = 0.23). Gross ecosystem productivity (GEP) and ecosystem respiration (RE), which together represent the primary components of NEE, were not necessarily more variable in the pine site; however, the coupling between annual GEP and RE was weaker in PP as compared to HW, contributing to higher overall variability in PP NEE. Our results identify at least two factors contributing to this decoupling: 1) an ice storm event, which reduced PP GEP while increasing or having no effect on PP RE, and 2) two severe drought events, which cause large reductions in PP GEP but not RE. Additionally, in both ecosystems, variability in GEP and NEE is strongly related to the length of the active season (r2 = 0.60 - 0.93), a variable reflecting the seasonality of carbon assimilation that is largely independent from patterns of leaf area development.

  20. The regulatory role of soil in the functioning of undisturbed biogeocenoses of the southern taiga

    NASA Astrophysics Data System (ADS)

    Trofimov, S. Ya.

    2010-09-01

    The results of complex investigations concerning the specific features of undisturbed southern taiga biogeocenoses’ functioning were summarized for the biogeocenoses at the Central Forest State Biosphere Nature Reserve (Tver oblast). In the soils of the different topographic elements, the water and temperature regimes and the pools of carbon, nitrogen, phosphorus, and potassium in the litter and mineral horizons were studied, as well as the rate of the falloff and litter decomposition in field and laboratory tests, the microbial biomass pool and structure, the abundance and diversity of the soil mesofauna, and the microbial transformation of the nitrogen compounds. In the biogeocenoses investigated, the transformation of carbon and nitrogen compounds is shown to be controlled by the biochemical composition of the falloff and the structure of the soil biota, which, in turn, are determined by the specific features of the water regime and the acid-base soil properties.

  1. Runoff and soil erosion for an undisturbed tropical woodland in the Brazilian Cerrado

    NASA Astrophysics Data System (ADS)

    Oliveira, Paulo Tarso S.; Nearing, Mark; Wendland, Edson

    2015-04-01

    The Brazilian Cerrado is a large and important economic and environmental region that is experiencing major loss of its natural landscapes due to pressures of food and energy production, which has caused large increases in soil erosion. However the magnitude of the soil erosion increases in this region is not well understood, in part because scientific studies of surface runoff and soil erosion are scarce or nonexistent in undisturbed Cerrado vegetation. In this study we measured natural rainfall-driven rates of runoff and soil erosion for an undisturbed tropical woodland classified as "cerrado sensu stricto denso" and bare soil to compute the Universal Soil Loss Equation (USLE) cover and management factor (C-factor) to help evaluate the likely effects of land use change on soil erosion rates. Replicated data on precipitation, runoff, and soil loss on plots (5 x 20 m) under bare soil and cerrado were collected for 55 erosive storms occurring in 2012 and 2013. The measured annual precipitation was 1247.4 mm and 1113.0 mm for 2012 and 2013, resulting in a rainfall erosivity index of 4337.1 MJ mm ha-1 h-1 and 3546.2 MJ mm ha-1 h-1, for each year respectively. The erosive rainfall represented 80concentrated in the wet season, which generally runs from October through March. In the plots on bare soil, the runoff coefficient for individual rainfall events (total runoff divided by total rainfall) ranged from 0.003 to 0.860 with an average value and standard deviation of 0.212 ± 0.187. Moreover, the runoff coefficient found for the bare soil plots (~20infiltration capacity. In forest areas the leaf litter and the more porous soil tend to promote the increase of infiltration and water storage, rather than rapid overland flow. Indeed, runoff coefficients ranged from 0.001 to 0.030 with an average of less than 1under undisturbed cerrado. The soil losses measured under bare soil and cerrado were 15.68 t ha-1yr-1 and 0.24 t ha-1 yr-1 in 2012, and 14.82 t ha-1 yr-1, 0.11 t ha-1

  2. Measurement of undisturbed di-nitrogen emissions from aquatic ecosystems

    NASA Astrophysics Data System (ADS)

    Qin, Shuping, Clough, Timothy, Lou, Jiafa; Hu, Chunsheng; Oenema, Oene; Wrage-Mönnig, Nicole; Zhang, Yuming

    2016-04-01

    Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N2) during the last century has greatly contributed to increased food production1-4. However, enriching the biosphere with Nr through N fertilizer production, combustion, and biological N2 fixation has also caused a series of negative effects on global ecosystems 5,6, especially aquatic ecosystems7. The main pathway converting Nr back into the atmospheric N2 pool is the last step of the denitrification process, i.e., the reduction of nitrous oxide (N2O) into N2 by micro-organisms7,8. Despite several attempts9,10, there is not yet an accurate, fast and direct method for measuring undisturbed N2 fluxes from denitrification in aquatic sediments at the field scale11-14. Such a method is essential to study the feedback of aquatic ecosystems to Nr inputs1,2,7. Here we show that the measurement of both N2O emission and its isotope signature can be used to infer the undisturbed N2 fluxes from aquatic ecosystems. The microbial reduction of N2O increases the natural abundance of 15N-N2O relative to 14N-N2O (δ15N-N2O). We observed linear relationships between δ15N-N2O and the logarithmic transformed N2O/(N2+N2O) emission ratios. Through independent measurements, we verified that the undisturbed N2 flux from aquatic ecosystems can be inferred from measurements of N2O emissions and the δ15N-N2O signature. Our method allows the determination of field-scale N2 fluxes from undisturbed aquatic ecosystems, and thereby allows model predictions of denitrification rates to be tested. The undisturbed N2 fluxes observed are almost one order of magnitude higher than those estimated by the traditional method, where perturbation of the system occurs, indicating that the ability of aquatic ecosystems to remove Nr may have been severely underestimated.

  3. Case study of airborne fungi according to air temperature and relative humidity in houses with semi-basements adjacent to a forested hillside.

    PubMed

    Bamba, Ikuko; Azuma, Michiyo; Hamada, Nobuo; Kubo, Hiroko; Isoda, Norio

    2014-01-01

    We studied airborne concentrations of fungal spores and the thermal environment in houses with semi-basements surrounded by a natural forest. We examined the relationship between airborne fungi and the thermal environment, surrounding natural environment, structures of houses and use of a dehumidifier. The subject residential area was located in the northern part of Nara city, Nara prefecture, Japan. Six detached houses were included in this study. In residential areas, outdoor airborne concentrations were high during summer and autumn, correlated with humidity. The presence of Basidiomycetes was particularly notable, although the indoor concentration was lower than the outdoor level. In the semi-basement rooms, relative humidity was nearly always >80% when the residence was built; however, both the indoor humidity and fungal concentrations decreased greatly when a dehumidifier was used in this study. High levels of Aspergillus and Basidiomycetes were detected in semi-basements. Basidiomycetes are likely of outdoor origin, whereas Aspergillus might grow indoors. Moreover, the composition of fungal species differed according to room-structure and usage. Due to the health risks associated with high indoor concentrations of fungi, the utilization of the semi-basement or basement space requires adequate ventilation and dehumidification, beginning immediately after construction.

  4. Effects of Long-Term Trampling on the Above-Ground Forest Vegetation and Soil Seed Bank at the Base of Limestone Cliffs

    NASA Astrophysics Data System (ADS)

    Rusterholz, Hans-Peter; Verhoustraeten, Christine; Baur, Bruno

    2011-11-01

    Exposed limestone cliffs in central Europe harbor a highly divers flora with many rare and endangered species. During the past few decades, there has been increasing recreational use of these cliffs, which has caused local environmental disturbances. Successful restoration strategies hinge on identifying critical limitations. We examined the composition of aboveground forest vegetation and density and species composition of seeds in the soil seed bank at the base of four limestone cliffs in mixed deciduous forests that are intensively disturbed by human trampling and at four undisturbed cliffs in the Jura Mountains in northwestern Switzerland. We found that long-term human trampling reduced total aboveground vegetation cover at the base of cliffs and caused a significant shift in the plant-species composition. Compared with undisturbed cliffs, total seed density was lower in disturbed cliffs. Human trampling also altered the species composition of seeds in the soil seed bank. Seeds of unintentionally introduced, stress-tolerant, and ruderal species dominated the soil seed bank at the base of disturbed cliffs. Our findings indicate that a restoration of degraded cliff bases from the existing soil seed bank would result in a substantial change of the original unique plant composition. Active seed transfer, or seed flux from adjacent undisturbed forest areas, is essential for restoration success.

  5. Effects of long-term trampling on the above-ground forest vegetation and soil seed bank at the base of limestone cliffs.

    PubMed

    Rusterholz, Hans-Peter; Verhoustraeten, Christine; Baur, Bruno

    2011-11-01

    Exposed limestone cliffs in central Europe harbor a highly divers flora with many rare and endangered species. During the past few decades, there has been increasing recreational use of these cliffs, which has caused local environmental disturbances. Successful restoration strategies hinge on identifying critical limitations. We examined the composition of aboveground forest vegetation and density and species composition of seeds in the soil seed bank at the base of four limestone cliffs in mixed deciduous forests that are intensively disturbed by human trampling and at four undisturbed cliffs in the Jura Mountains in northwestern Switzerland. We found that long-term human trampling reduced total aboveground vegetation cover at the base of cliffs and caused a significant shift in the plant-species composition. Compared with undisturbed cliffs, total seed density was lower in disturbed cliffs. Human trampling also altered the species composition of seeds in the soil seed bank. Seeds of unintentionally introduced, stress-tolerant, and ruderal species dominated the soil seed bank at the base of disturbed cliffs. Our findings indicate that a restoration of degraded cliff bases from the existing soil seed bank would result in a substantial change of the original unique plant composition. Active seed transfer, or seed flux from adjacent undisturbed forest areas, is essential for restoration success.

  6. Home range and movements of boreal toads in undisturbed habitat

    USGS Publications Warehouse

    Muths, E.

    2003-01-01

    I sampled movements and amount of area used by boreal toads (Bufo boreas) between June and October for 3 yr. Females were found farther from the breeding site than were males, and mean home ranges, as calculated by the adaptive kernel method, were four times larger for females than for males. Temperature and snow accumulation were comparable over the study, but data collection was hampered by mortality of animals caused by an outbreak of amphibian chytridiomycosis in yr 2. These data provide insight into use of habitat by boreal toads in undisturbed areas but may not be typical of a completely healthy population.

  7. Hydrologic Controls on Dissolved Organic Matter Mobilization and Transport within Undisturbed Soils

    NASA Astrophysics Data System (ADS)

    Xu, N.; Saiers, J.

    2007-12-01

    Dissolved organic matter (DOM) in soils plays an important role in the transport of nutrients and contaminants through the terrestrial environment. Subsurface pathways deliver a significant portion of carbon to streams that drain forested and agricultural watersheds. Although the importance of rainfall events to the DOM soil-water flux is well known, the hydrologic factors that govern this flux have not been fully examined. The primary purpose of this study is to investigate the soil and rainfall characteristics controlling the mobilization and transport of DOM in undisturbed soils. Intact soil columns including topsoil and subsoil layers were taken from the Harvard forest in Petersham, MA. Unsaturated flow conditions were maintained by applying suction to the bottom of the soil columns. The columns were irrigated by series of interrupted rainfall events using the same total volume of artificial rain water. Preliminary experiments showed continuous leaching of DOM (measured by dissolved organic carbon) with an initial peak in concentration that coincided with the passage of the wetting front. The leached DOM was also characterized by UV absorbance, fluorescence spectroscopy in the emission mode, and additional spectroscopic derived indexes such as the humification index. Ongoing column experiments are focusing on the effects of rainfall intensity, frequency, and rainfall history on DOM mobilization and transport through natural, structured soils. These investigations can elucidate the influence of factors that are associated with climate change on DOC dynamics. Results of our analyses should also provide insight into the mechanisms that govern DOM mobilization in soils.

  8. Photoacoustic FTIR spectroscopic study of undisturbed human cortical bone

    NASA Astrophysics Data System (ADS)

    Gu, Chunju; Katti, Dinesh R.; Katti, Kalpana S.

    2013-02-01

    Chemical pretreatment has been the prevailing sample preparation procedure for infrared (IR) spectroscopic studies on bone. However, experiments have indicated that chemical pretreatment can potentially affect the interactions between the components. Typically the IR techniques have involved transmission experiments. Here we report experimental studies using photoacoustic Fourier transform infrared spectroscopy (PA-FTIR). As a nondestructive technique, PA-FTIR can detect absorbance spectrum from a sample at controllable sampling depth and with little or no sample preparation. Additionally, the coupling inert gas, helium, which is utilized in the PA-FTIR system, can inhibit bacteria growth of bone by displacing oxygen. Therefore, we used this technique to study the undisturbed human cortical bone. It is found that photoacoustic mode (linear-scan, LS-PA-FTIR) can obtain basically similar spectra of bone as compared to the traditional transmission mode, but it seems more sensitive to amide III and ν2 carbonate bands. The ν3 phosphate band is indicative of detailed mineral structure and symmetry of native bone. The PA-FTIR depth profiling experiments on human cortical bone also indicate the influence of water on OH band and the cutting effects on amide I and mineral bands. Our results indicate that phosphate ion geometry appears less symmetric in its undisturbed state as detected by the PA-FTIR as compared to higher symmetry observed using transmission techniques on disturbed samples. Moreover, the PA-FTIR spectra indicate a band at 1747 cm-1 possibly resulting from Cdbnd O stretching of lipids, cholesterol esters, and triglycerides from the arteries. Comparison of the spectra in transverse and longitudinal cross-sections demonstrates that, the surface area of the longitudinal section bone appears to have more organic matrix exposed and with higher mineral stoichiometry.

  9. Effects of Disturbances on Vegetation Composition and Permafrost Thaw in Boreal Forests and Tundra Ecosystems of the Siberian Arctic

    NASA Astrophysics Data System (ADS)

    Ramos, E.; Alexander, H. D.; Natali, S.

    2014-12-01

    In Arctic ecosystems, climate-driven changes to the thermal regime of permafrost soils have the potential to create surface disturbances that influence vegetation dynamics and underlying soil properties. Disturbance-mediated changes in vegetation are important because vegetation and the accumulation of soil organic matter drive ecosystem carbon (C) dynamics and contribute to the insulation of soils and protection of permafrost from thaw. We examined the effect of two disturbance types—thermokarsts and frost boils—to determine disturbance effects on the vegetation community and soil properties in northeast Siberia. In summer 2014, we measured vegetation cover, soil moisture, soil temperature, and thaw depth in two thermokarst sites within boreal forests, two frost boil sites in tundra, and in adjacent undisturbed sites within both ecosystems. Both thermokarst and frost boils resulted in decreased vegetation cover and greater exposure of mineral soils (10-40% bare soils vs. 0% in undisturbed), and consequently, 2-3 times higher soil temperature and deeper thaw depth. Compared to undisturbed areas, soil moisture was 3-4 times higher in thermokarst areas but 1.2-2 times lower in frost boil areas, which reflected differences in microtopography between these two disturbance types. In both thermokarst and frost boil disturbed areas, deciduous and evergreen shrubs covered only 5 and 10%, respectively, compared to approximately 10 and 20%, respectively, in undisturbed areas. In general, graminoids were substantially more abundant (2-20 times) in disturbed areas than in those undisturbed. These results highlight important linkages between disturbances, vegetation communities, and permafrost soils, and contribute to our understanding of how changes in arctic vegetation dynamics as direct and/or indirect consequences of climate change have the potential to impact permafrost C pools.

  10. Three new species of Aspergillus from Amazonian forest soil (Ecuador).

    PubMed

    Mares, Donatella; Andreotti, Elisa; Maldonado, Maria Elena; Pedrini, Paola; Colalongo, Chiara; Romagnoli, Carlo

    2008-09-01

    From an undisturbed natural forest soil in Ecuador, three fungal strains of the genus Aspergillus were isolated. Based on molecular and morphological features they are described as three new species, named A. quitensis, A. amazonicus, and A. ecuadorensis.

  11. Monitoring of Gasoline-ethanol Degradation In Undisturbed Soil

    NASA Astrophysics Data System (ADS)

    Österreicher-Cunha, P.; Nunes, C. M. F.; Vargas, E. A.; Guimarães, J. R. D.; Costa, A.

    Environmental contamination problems are greatly emphasised nowadays because of the direct threat they represent for human health. Traditional remediation methods fre- quently present low efficiency and high costs; therefore, biological treatment is being considered as an accessible and efficient alternative for soil and water remediation. Bioventing, commonly used to remediate petroleum hydrocarbon spills, stimulates the degradation capacity of indigenous microorganisms by providing better subsur- face oxygenation. In Brazil, gasoline and ethanol are mixed (78:22 v/v); some authors indicate that despite gasoline high degradability, its degradation in subsurface is hin- dered by the presence of much more rapidly degrading ethanol. Contaminant distribu- tion and degradation in the subsurface can be monitored by several physical, chemical and microbiological methodologies. This study aims to evaluate and follow the degra- dation of a gasoline-ethanol mixture in a residual undisturbed tropical soil from Rio de Janeiro. Bioventing was used to enhance microbial degradation. Shifts in bacte- rial culturable populations due to contamination and treatment effects were followed by conventional microbiology methods. Ground Penetrating Radar (GPR) measure- ments, which consist of the emission of electro-magnetic waves into the soil, yield a visualisation of contaminant degradation because of changes in soil conductivity due to microbial action on the pollutants. Chemical analyses will measure contaminant residue in soil. Our results disclosed contamination impact as well as bioventing stim- ulation on soil culturable heterotrophic bacterial populations. This multidisciplinary approach allows for a wider evaluation of processes occurring in soil.

  12. Concentrated flow erodibility for physically-based erosion models: temporal variability in disturbed and undisturbed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current physically based overland flow erosion models for rangeland application do not separate disturbed and undisturbed conditions in modeling concentrated flow erosion. In this study, concentrated flow simulations on disturbed and undisturbed rangelands were used to estimate the erodibility and t...

  13. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest.

    PubMed

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species.

  14. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest

    PubMed Central

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. PMID:27379260

  15. Forest edges: Effects on vegetation, environmental gradients and local avian communities in the Sierra Juarez, Oaxaca, Mexico

    NASA Astrophysics Data System (ADS)

    Burcsu, Theresa Katherine

    Edge effects are among the most serious threats to forest integrity because as global forest cover decreases overall, forest edge influence increases proportionally, driving habitat change and loss. Edge effects occur at the division between adjacent habitat types. Our understanding of edge effects comes mainly from tropical wet, temperate and boreal forests. Because forest structure in moisture-limited forests differs from wetter forest types, edge dynamics are likely to differ as well. Moreover, dry forests in the tropics have been nearly eliminated or exist only as forest fragments, making edge influence an important conservation and management concern for remaining dry forests. This study addresses this gap in the edge influence knowledge by examining created, regenerating edges associated with forest management in a seasonally dry pine-oak forest of Oaxaca, creating a new data point in edge effects research. In this study I used Landsat TM imagery and a modified semivariance analysis to estimate the distance of edge influence for vegetation. I also used field methods to characterize forest structure and estimate edge influence on canopy and subcanopy vegetation. To finalize the project I extended the study to bird assemblages to identify responses and habitat preferences to local-scale changes associated with regenerating edges created by group-selection timber harvest. Remote sensing analysis estimated that the distance of edge influence was 30-90 m from the edge. Vegetation analysis suggested that edge effects were weak relative to wetter forest types and that remote sensing data did not provide an estimate that was directly applicable to field-measured vegetative edge effects. The bird assemblages likewise responded weakly to habitat change associated with edge effect. Open canopy structure, simple vertical stratigraphy, and topographic variation create forest conditions in which small openings do not create a high contrast to undisturbed forest. Thus, in

  16. The influence of forest roads on runoff generation and soil erosion -- an assessment based on small scale rainfall simulation

    NASA Astrophysics Data System (ADS)

    Zemke, Julian J.

    2016-04-01

    In the course of forestry operations such as pruning and harvesting, a dense network of forest roads and skid trails has to be established. Due to mostly insufficient soil protective measures, the frequent overpassing of previously undisturbed topsoil with heavy forestry equipment on skid trails generates severe soil compaction. On persistent forest roads, the constructional layout and fortification also cause an increase of soil density. As a result of soil compaction, infiltration capacities are significantly reduced. Therefore, the affected areas tend to generate overland flow much quicker than undisturbed soil and differ considerably from the adjacent forest topsoil. As a consequence, decentral water retention on the watershed scale can be affected, if the road network is too dense and/or covers too much of the catchment's surface. Another consequence is the increase of soil erosion rates caused by erosive overland flows and the removal of vegetation cover on roads and skid trails. Again, the road and path surfaces differ significantly from adjacent forest soils where soil erosion rates normally tend to be equal or less than the soil renewal rates. To quantify the influence of forest roads and skid trails on runoff generation and soil erosion rates in a forested catchment area, rainfall simulations were carried out. A small scale rainfall simulator with a plot area of 0,64 m2 was used to simulate rainfall events with an intensity of 45 mm/h, a duration of 3 x 30 minutes and a kinetic energy of 4,6 J/m2*mm. Overland flow and eroded material were collected in a high temporal resolution of 1 minute. The sampled roads and skid trails were differentiated and categorized according to their constructional layout. Beyond that, rutted and unrutted road areas were distinguished. To obtain a benchmark for natural soil characteristics, undisturbed forest soils were also examined. The results show a significant influence of traffic induced soil compaction on the

  17. Human population and socioeconomic modulators of conservation performance in 788 Amazonian and Atlantic Forest reserves.

    PubMed

    de Marques, Ana Alice B; Schneider, Mauricio; Peres, Carlos A

    2016-01-01

    Protected areas form a quintessential component of the global strategy to perpetuate tropical biodiversity within relatively undisturbed wildlands, but they are becoming increasingly isolated by rapid agricultural encroachment. Here we consider a network of 788 forest protected areas (PAs) in the world's largest tropical country to examine the degree to which they remain intact, and their responses to multiple biophysical and socioeconomic variables potentially affecting natural habitat loss under varying contexts of rural development. PAs within the complex Brazilian National System of Conservation Units (SNUC) are broken down into two main classes-strictly protected and sustainable use. Collectively, these account for 22.6% of the forest biomes within Brazil's national territory, primarily within the Amazon and the Atlantic Forest, but are widely variable in size, ecoregional representation, management strategy, and the degree to which they are threatened by human activities both within and outside reserve boundaries. In particular, we examine the variation in habitat conversion rates in both strictly protected and sustainable use reserves as a function of the internal and external human population density, and levels of land-use revenue in adjacent human-dominated landscapes. Our results show that PAs surrounded by heavily settled agro-pastoral landscapes face much greater challenges in retaining their natural vegetation, and that strictly protected areas are considerably less degraded than sustainable use reserves, which can rival levels of habitat degradation within adjacent 10-km buffer areas outside.

  18. Human population and socioeconomic modulators of conservation performance in 788 Amazonian and Atlantic Forest reserves

    PubMed Central

    Schneider, Mauricio; Peres, Carlos A.

    2016-01-01

    Protected areas form a quintessential component of the global strategy to perpetuate tropical biodiversity within relatively undisturbed wildlands, but they are becoming increasingly isolated by rapid agricultural encroachment. Here we consider a network of 788 forest protected areas (PAs) in the world’s largest tropical country to examine the degree to which they remain intact, and their responses to multiple biophysical and socioeconomic variables potentially affecting natural habitat loss under varying contexts of rural development. PAs within the complex Brazilian National System of Conservation Units (SNUC) are broken down into two main classes—strictly protected and sustainable use. Collectively, these account for 22.6% of the forest biomes within Brazil’s national territory, primarily within the Amazon and the Atlantic Forest, but are widely variable in size, ecoregional representation, management strategy, and the degree to which they are threatened by human activities both within and outside reserve boundaries. In particular, we examine the variation in habitat conversion rates in both strictly protected and sustainable use reserves as a function of the internal and external human population density, and levels of land-use revenue in adjacent human-dominated landscapes. Our results show that PAs surrounded by heavily settled agro-pastoral landscapes face much greater challenges in retaining their natural vegetation, and that strictly protected areas are considerably less degraded than sustainable use reserves, which can rival levels of habitat degradation within adjacent 10-km buffer areas outside. PMID:27478703

  19. Biogeochemical characterization of an undisturbed highly acidic, metal-rich bryophyte habitat, east-central Alaska, U.S.A.

    USGS Publications Warehouse

    Gough, L.P.; Eppinger, R.G.; Briggs, P.H.; Giles, S.

    2006-01-01

    We report on the geochemistry of soil and bryophyte-laden sediment and on the biogeochemistry of willows growing in an undisturbed volcanogenic massive sulfide deposit in the Alaska Range ecoregion of east-central Alaska. We also describe an unusual bryophyte assemblage found growing in the acidic metal-rich waters that drain the area. Ferricrete-cemented silty alluvial sediments within seeps and streams are covered with the liverwort Gymnocolea inflata whereas the mosses Polytrichum commune and P. juniperinum inhabit the area adjacent to the water and within the splash zone. Both the liverwort-encrusted sediment and Polytrichum thalli have high concentrations of major and trace metal cations (e.g., Al, As, Cu, Fe, Hg, La, Mn, Pb, and Zn). Soils in the area do not reflect the geochemical signature of the mineral deposit and we postulate they are influenced by the chemistry of eolian sediments derived from outside the deposit area. The willow, Salix pulchra, growing mostly within and adjacent to the larger streams, has much higher concentrations of Al, As, Cd, Cr, Fe, La, Pb, and Zn when compared to the same species collected in non-mineralized areas of Alaska. The Cd levels are especially high and are shown to exceed, by an order of magnitude, levels demonstrated to be toxic to ptarmigan in Colorado. Willow, growing in this naturally occurring metal-rich Red Mountain alteration zone, may adversely affect the health of browsing animals. ?? 2006 Regents of the University of Colorado.

  20. A simple hypothesis of how leaf and canopy-level transpiration and assimilation respond to elevated CO2 reveals distinct response patterns between disturbed and undisturbed vegetation

    NASA Astrophysics Data System (ADS)

    Donohue, Randall J.; Roderick, Michael L.; McVicar, Tim R.; Yang, Yuting

    2017-01-01

    Elevated CO2 increases leaf-level water-use efficiency (ω) almost universally. How canopy-level transpiration and assimilation fluxes respond to increased ω is currently unclear. We present a simple, resource-availability-based hypothesis of how equilibrium (or mature) leaf and canopy transpiration and assimilation rates, along with leaf area index (L), respond to elevated CO2. We quantify this hypothesis in the form of a model and test it against observations from eight Free Air CO2 Enrichment sites that span a wide range of resource availabilities. Sites were grouped according to vegetation disturbance status. We find the model adequately accounts for the responses of undisturbed vegetation (R2 = 0.73, 11% error) but cannot account for the responses of disturbed vegetation (R2 = 0.47, 17% error). At undisturbed sites, the responses of L and of leaf and canopy transpiration vary predictably (7% error) with resource availability, whereas the leaf assimilation response is less predictable. In contrast, the L and transpiration flux responses at the disturbed (mostly forested) sites are highly variable and are not strongly related to resource availability. Initial analyses suggest that they are more strongly related to regrowth age than to resource availability. We conclude that (i) our CO2 response hypothesis is valid for capturing the responses of undisturbed vegetation only, (ii) that the responses of disturbed vegetation are distinctly different from undisturbed vegetation, and (iii) that these differences need to be accounted for when predicting the effects of elevated CO2 on land surface processes generally, and on leaf area and water fluxes in particular.

  1. Post-disturbance plant community dynamics following a rare natural-origin fire in a Tsuga canadensis forest.

    PubMed

    Murray, Bryan D; Holmes, Stacie A; Webster, Christopher R; Witt, Jill C

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000-3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species.

  2. Post-Disturbance Plant Community Dynamics following a Rare Natural-Origin Fire in a Tsuga canadensis Forest

    PubMed Central

    Murray, Bryan D.; Holmes, Stacie A.; Webster, Christopher R.; Witt, Jill C.

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000–3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species. PMID:22928044

  3. Comparison of Shear Strength Properties for Undisturbed and Reconstituted Parit Nipah Peat, Johor

    NASA Astrophysics Data System (ADS)

    Azhar, A. T. S.; Norhaliza, W.; Ismail, B.; Abdullah, M. E.; Zakaria, M. N.

    2016-11-01

    Shear strength of soil is required to determine the soil stability and design the foundations. Peat is known as a soil with complex natural formations which also contributes problems to the researchers, developers, engineers and contractors in constructions and infrastructures. Most researchers conducted experiment and investigation of shear strength on peat using shear box test and simple shear test, but only a few had discovered the behavior of peat using triaxial consolidated undrained test. The aim of this paper is to determine the undrained shear strength properties of reconstituted peat and undisturbed peat of Parit Nipah, Johor for comparison purposes. All the reconstituted peat samples were formed with the size that passed opening sieve 3.35 mm and preconsolidation pressure at 100 kPa. The result of undrained shear strength of reconstituted peat was 21kPa for cohesion with the angle of friction, 41° compare to the undisturbed peat with cohesion 10 kPa and angle of friction, 16°. The undrained shear strength properties result obtained shows that the reconstituted peat has higher strength than undisturbed peat. For relationship deviator stress-strain, σd max and excess pore pressure, Δu, it shows that both of undisturbed and reconstituted gradually increased when σ’ increased, but at the end of the test, the values are slightly dropped. The physical properties of undisturbed and reconstituted peat were also investigated to correlate with the undrained shear strength results.

  4. Role and Variation of the Amount and Composition of Glomalin in Soil Properties in Farmland and Adjacent Plantations with Reference to a Primary Forest in North-Eastern China

    PubMed Central

    Wang, Qiong; Wang, Wenjie; He, Xingyuan; Zhang, Wentian; Song, Kaishan; Han, Shijie

    2015-01-01

    The glycoprotein known as glomalin-related soil protein (GRSP) is abundantly produced on the hyphae and spores of arbuscular mycorrhizal fungi (AMF) in soil and roots. Few studies have focused on its amount, composition and associations with soil properties and possible land-use influences, although the data hints at soil rehabilitation. By choosing a primary forest soil as a non-degraded reference, it is possible to explore whether afforestation can improve degraded farmland soil by altering GRSP. In this paper, close correlations were found between various soil properties (soil organic carbon, nitrogen, pH, electrical conductivity (EC), and bulk density) and the GRSP amount, between various soil properties and GRSP composition (main functional groups, fluorescent substances, and elements). Afforestation on farmland decreased the EC and bulk density (p < 0.05). The primary forest had a 2.35–2.56-fold higher GRSP amount than those in the plantation forest and farmland, and GRSP composition (tryptophan-like and fulvic acid-like fluorescence; functional groups of C–H, C–O, and O–H; elements of Al, O, Si, C, Ca, and N) in primary forest differed from those in plantation forest and farmland (p < 0.05). However, no evident differences in GRSP amount and composition were observed between the farmland and the plantation forest. Our finding highlights that 30 years poplar afforestation on degraded farmland is not enough to change GRSP-related properties. A longer period of afforestation with close-to-nature managements may favor the AMF-related underground recovery processes. PMID:26430896

  5. Role and Variation of the Amount and Composition of Glomalin in Soil Properties in Farmland and Adjacent Plantations with Reference to a Primary Forest in North-Eastern China.

    PubMed

    Wang, Qiong; Wang, Wenjie; He, Xingyuan; Zhang, Wentian; Song, Kaishan; Han, Shijie

    2015-01-01

    The glycoprotein known as glomalin-related soil protein (GRSP) is abundantly produced on the hyphae and spores of arbuscular mycorrhizal fungi (AMF) in soil and roots. Few studies have focused on its amount, composition and associations with soil properties and possible land-use influences, although the data hints at soil rehabilitation. By choosing a primary forest soil as a non-degraded reference, it is possible to explore whether afforestation can improve degraded farmland soil by altering GRSP. In this paper, close correlations were found between various soil properties (soil organic carbon, nitrogen, pH, electrical conductivity (EC), and bulk density) and the GRSP amount, between various soil properties and GRSP composition (main functional groups, fluorescent substances, and elements). Afforestation on farmland decreased the EC and bulk density (p < 0.05). The primary forest had a 2.35-2.56-fold higher GRSP amount than those in the plantation forest and farmland, and GRSP composition (tryptophan-like and fulvic acid-like fluorescence; functional groups of C-H, C-O, and O-H; elements of Al, O, Si, C, Ca, and N) in primary forest differed from those in plantation forest and farmland (p < 0.05). However, no evident differences in GRSP amount and composition were observed between the farmland and the plantation forest. Our finding highlights that 30 years poplar afforestation on degraded farmland is not enough to change GRSP-related properties. A longer period of afforestation with close-to-nature managements may favor the AMF-related underground recovery processes.

  6. Carbon pools recover more quickly than plant biodiversity in tropical secondary forests

    PubMed Central

    Martin, Philip A.; Newton, Adrian C.; Bullock, James M.

    2013-01-01

    Although increasing efforts are being made to restore tropical forests, little information is available regarding the time scales required for carbon and plant biodiversity to recover to the values associated with undisturbed forests. To address this knowledge gap, we carried out a meta-analysis comparing data from more than 600 secondary tropical forest sites with nearby undisturbed reference forests. Above-ground biomass approached equivalence to reference values within 80 years since last disturbance, whereas below-ground biomass took longer to recover. Soil carbon content showed little relationship with time since disturbance. Tree species richness recovered after about 50 years. By contrast, epiphyte richness did not reach equivalence to undisturbed forests. The proportion of undisturbed forest trees and epiphyte species found in secondary forests was low and changed little over time. Our results indicate that carbon pools and biodiversity show different recovery rates under passive, secondary succession and that colonization by undisturbed forest plant species is slow. Initiatives such as the Convention on Biological Diversity and REDD+ should therefore encourage active management to help to achieve their aims of restoring both carbon and biodiversity in tropical forests. PMID:24197410

  7. Retention and remobilization of stabilized silver nanoparticles in an undisturbed loamy sand soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Column experiments were conducted with undisturbed loamy sand soil under unsaturated conditions (around 90% saturation degree) to investigate the retention of surfactant stabilized silver nanoparticles (AgNPs) with various input concentration (Co), flow velocity, and ionic strength (IS), and the rem...

  8. Pore space statistics from the X-ray CT of large undisturbed soil columns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large soil columns need to be studied to infer geometric properties of macropores and their role in flow and transport phenomena, especially when colloid or colloid-facilitated transport is of interest. We have sampled and studied undisturbed columns (7.5 cm ID, 20 cm length) of the Taylor soil from...

  9. Undisturbed soil columns for lysimetry I. Collection, field testing and construction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods to obtain undisturbed soil columns are vital to the study of solute transport in soils. Of particular concern is the maintenance of the soil's structural integrity in order to preserve preferential flow processes. A simple and inexpensive method of excavation was developed for 41 cm diamete...

  10. Dust emissions from undisturbed and disturbed, crusted playa surfaces: cattle trampling effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dry playa lake beds can be significant sources of fine dust emission. This study used a portable field wind tunnel to quantify the PM10 emissions from a bare, fine-textured playa surface located in the far northern Chihuahua Desert. The natural, undisturbed crust and its subjection to two levels of ...

  11. MEASUREMENT OF EFFECTIVE AIR DIFFUSION COEFFICIENTS FOR TRICHLOROETHENE IN UNDISTURBED SOIL CORES. (R826162)

    EPA Science Inventory

    Abstract

    In this study, we measure effective diffusion coefficients for trichloroethene in undisturbed soil samples taken from Picatinny Arsenal, New Jersey. The measured effective diffusion coefficients ranged from 0.0053 to 0.0609 cm2/s over a range of air...

  12. Above and below ground carbon stocks in northeast Siberia tundra ecosystems: a comparison between disturbed and undisturbed areas

    NASA Astrophysics Data System (ADS)

    Weber, L. R.; Pena, H., III; Curasi, S. R.; Ramos, E.; Loranty, M. M.; Alexander, H. D.; Natali, S.

    2014-12-01

    Changes in arctic tundra vegetation have the potential to alter the regional carbon (C) budget, with feedback implications for global climate. A number of studies have documented both widespread increases in productivity as well as shifts in the dominant vegetation. In particular, shrubs have been replacing other vegetation, such as graminoids, in response to changes in their environment. Shrub expansion is thought to be facilitated by exposure of mineral soil and increased nutrient availability, which are often associated with disturbance. Such disturbances can be naturally occurring, typically associated with permafrost degradation or with direct anthropogenic causes such as infrastructure development. Mechanical disturbance associated with human development is not uncommon in tundra and will likely become more frequent as warming makes the Arctic more hospitable for resource extraction and other human activities. As such, this type of disturbance will become an increasingly important component of tundra C balance. Both increased productivity and shrub expansion have clear impacts on ecosystem C cycling through increased C uptake and aboveground (AG) storage. What is less clear, however, are the concurrent changes in belowground (BG) C storage. Here we inventoried AG and BG C stocks in disturbed and undisturbed tundra ecosystems to determine the effects of disturbance on tundra C balance. We measured differences in plant functional type, AG and BG biomass, soil C, and specific leaf area (SLA) for the dominant shrub (Salix) in 2 tundra ecosystems in northern Siberia—an undisturbed moist acidic tundra and an adjacent ecosystem that was used as a road ~50 years ago. Deciduous shrubs and grasses dominated both ecosystems, but biomass for both functional types was higher in the disturbed area. SLA was also higher inside the disturbance. Conversely, nonvascular plants and evergreen shrubs were less abundant in the disturbed area. BG plant biomass was substantially

  13. Ground water nitrate removal in subsoil of forested and mowed riparian buffer zones

    SciTech Connect

    Addy, K.L.; Gold, A.J.; Groffman, P.M.; Jacinthe, P.A.

    1999-05-01

    The authors studied two similar riparian sites in southern New England and examined ground water nitrate (NO{sub 3}{sup {minus}}-N) removal in the subsurface of mowed (i.e., herbaceous) vs. forested (i.e., woody) vegetation. Each site consisted of poorly drained, fine to medium sands and contained adjacent areas of mowed and forested vegetation. They dosed mesocosms with bromide and {sup 15}N labeled NO{sub 3}{sup {minus}}-N amended ground water to simulate the shallow ground water NO{sub 3}{sup {minus}}-N dynamics of riparian buffers zones. Mesocosms were composed of undisturbed, horizontal soil cores extracted from seasonally saturated subsoil. The authors observed substantial ground water NO{sub 3}{sup {minus}}-N removal and denitrification at all locations. Ground water NO{sub 3}{sup {minus}}-N removal rates were significantly correlated with carbon-enriched patches of organic matter. This correlation supports previous work that patches function as hotspots of microbial activity in the subsoil. Within each site, they found no significant difference in ground water NO{sub 3}{sup {minus}}-N removal rates in the subsoil of forested and mowed areas and they noted tree roots throughout the subsoil of the mowed areas. They found that ground water NO{sub 3}{sup {minus}}-N removal rates differed significantly between similar sites. They caution against ascribing specific ground water NO{sub 3}{sup {minus}}-N removal rates to different riparian aboveground vegetation types without recognizing the importance of site differences, e.g., water table dynamics, land use legacy and adjacent vegetation. Riparian zones composed of a mix of forested and mowed vegetation, common in agroforestry and suburban land uses, may remove substantial amounts of ground water NO{sub 3}{sup {minus}}-N.

  14. Floristic and structural status of forests in permanent preservation areas of Moju river basin, Amazon region.

    PubMed

    Oliveira, J C; Vieira, I C G; Almeida, A S; Silva, C A

    2016-01-01

    The goal of this study is to analyze the floristic patterns and the structure of disturbed and undisturbed upland forests, in Permanent Preservation Areas (PPAs) along the Moju river, in the Brazilian state of Pará. Trees with a diameter equal to or larger than 10cm at 1.30m from the ground (DBH) ≥10cm were analyzed for the upper stratum. For the middle stratum, individuals with DBH between 4.99 and 9.99cm were sampled. Forty-five families and 221 species were found in disturbed forests, and 43 families and 208 species in undisturbed forests. Floristic similarity was high between strata and between forest types, with values above 50%. Similarity was highest between middle strata. The most species-abundant families in undisturbed forests were Fabaceae, Sapotaceae, Chrysobalanaceae and Myrtaceae; the species with the highest density there were Eschweilera grandiflora, Licania sclerophylla and Zygia cauliflora. In disturbed forests, the dominant families were Fabaceae, Sapotaceae, Lecythidaceae and Melastomataceae. The Shannon-Wiener diversity index was 3.21 for undisturbed forests and 2.85 for disturbed forests. Non-metric multidimensional scaling (MDS) analysis did not group the forests by their floristic composition in both upper and middle strata. Overall, the PPA forests along the Moju river, even if disturbed, did not show major floristic changes but substantially change their structural characteristics.

  15. Soil respiration patterns in root gaps 27 years after small scale experimental disturbance in Pinus contorta forests

    NASA Astrophysics Data System (ADS)

    Baker, S.; Berryman, E.; Hawbaker, T. J.; Ewers, B. E.

    2015-12-01

    While much attention has been focused on large scale forest disturbances such as fire, harvesting, drought and insect attacks, small scale forest disturbances that create gaps in forest canopies and below ground root and mycorrhizal networks may accumulate to impact regional scale carbon budgets. In a lodgepole pine (Pinus contorta) forest near Fox Park, WY, clusters of 15 and 30 trees were removed in 1988 to assess the effect of tree gap disturbance on fine root density and nitrogen transformation. Twenty seven years later the gaps remain with limited regeneration present only in the center of the 30 tree plots, beyond the influence of roots from adjacent intact trees. Soil respiration was measured in the summer of 2015 to assess the influence of these disturbances on carbon cycling in Pinus contorta forests. Positions at the centers of experimental disturbances were found to have the lowest respiration rates (mean 2.45 μmol C/m2/s, standard error 0.17 C/m2/s), control plots in the undisturbed forest were highest (mean 4.15 μmol C/m2/s, standard error 0.63 C/m2/s), and positions near the margin of the disturbance were intermediate (mean 3.7 μmol C/m2/s, standard error 0.34 C/m2/s). Fine root densities, soil nitrogen, and microclimate changes were also measured and played an important role in respiration rates of disturbed plots. This demonstrates that a long-term effect on carbon cycling occurs when gaps are created in the canopy and root network of lodgepole forests.

  16. Diurnal Changes of The Ion Densities In The Undisturbed Mesosphere and Lower Thermosphere

    NASA Astrophysics Data System (ADS)

    Kazil, J.; Kopp, E.; Chabrillat, S.; Bishop, J.

    Ions are produced in the undisturbed atmosphere by solar X-ray and EUV radiation and by Galactic Cosmic Rays. The production from cosmic rays is constant throughout the day, whereas the production from solar radiation depends on the solar zenith angle. In addition, direct sunlight interacts with the ions and affects the ion chemistry. At night, below approximately 80km, there is no significant contribution to the ion production from solar light. Above this level (up to approximately 160km), scattered solar Lyman- and - radiation is the main nighttime source for ions. We use the University of Bern Atmospheric Ion Model (UBAIM), fed with neutral data from the NCAR SOCRATES model, with solar flux data from the SOLAR2000 model, and with numerical nighttime Lyman- and - fluxes to investigate the diurnal changes of the ion densities in the undisturbed mesosphere and lower thermosphere (50-120km log-p altitude).

  17. Elsaesser variable analysis of fluctuations in the ion foreshock and undisturbed solar wind

    NASA Technical Reports Server (NTRS)

    Labelle, James; Treumann, Rudolf A.; Marsch, Eckart

    1994-01-01

    Magnetohydrodynamics (MHD) fluctuations in the solar wind have been investigated previously by use of Elsaesser variables. In this paper, we present a comparison of the spectra of Elsaesser variables in the undisturbed solar wind at 1 AU and in the ion foreshock in front of the Earth. Both observations take place under relatively strong solar wind flow speed conditions (approximately equal 600 km/s). In the undisturbed solar wind we find that outward propagating Alfven waves dominate, as reported by other observers. In the ion foreshock the situation is more complex, with neither outward nor inward propagation dominating over the entire range investigated (1-10 mHz). Measurements of the Poynting vectors associated with the fluctuations are consistent with the Elsaesser variable analysis. These results generally support interpretations of the Elsaesser variables which have been made based strictly on solar wind data and provide additional insight into the nature of the ion foreshock turbulence.

  18. The role of tree uprooting dynamics on the dynamics of Fe (Mn, Al and Si) forms in different forest soils

    NASA Astrophysics Data System (ADS)

    Tejnecký, V.; Samonil, P.; Boruvka, L.; Nikodem, A.; Drabek, O.; Valtera, M.

    2013-12-01

    Tree uprooting dynamics plays an important role in the development of forest ecosystems. This process causes bioturbation of soils and creates new microenvironments which consist of pits and mounds. These microtopographical forms could persist for some thousands of years. Pits and mounds undergo different pedogenesis in comparison to adjacent undisturbed soils. The stage of pedogenesis can be assessed according to the results of fractionation of Fe and also partially Mn, Al and Si. The main aim of this contribution is to assess the fractionation of Fe, Mn, Al and Si for three different soil regions. Soil samples were collected at three localities occurred along hypothetical gradient of soil weathering and leaching processes: The first was a (spruce)-fir-beech natural forest in the Razula region. The second location is the same type of natural forest in Zofin; however it has contrasting lithology. Both these natural forests are located in the Czech Republic (CZ). The third forest was a northern hardwood forest in Upper Peninsula, Michigan, USA. The prevailing soil types - Haplic Cambisols have formed on flysch parent materials in the Razula reserve; Entic Podzols have developed on granite residuum at the Zofin reserve, and Albic Podzols occurred in outwash parent materials at the Michigan sites (Šamonil et al., in press). In total 790 soil samples were analysed. These samples were collected from 5 depths (0-10, 15, 30, 50 and 100 cm) within the pit, mound and control, currently undisturbed position. For each sample, content of Fe (and Mn, Al, Si) forms: exchangeable, crystalline, and amorphous together with organically complexed Fe were determined. We generally observed an increased content of Fe soil forms in the pits of studied treethrows. The content of Fe forms increased along depth gradient at the disturbed sites. However, exchangeable Fe was most abundant in the 0-10cm layer which corresponds to the A horizon. Naturally, if present, the E horizon exhibited

  19. Nutrient loss accelerated by clear-cutting of a forest ecosystem

    USGS Publications Warehouse

    Bormann, F.H.; Likens, G.E.; Fisher, D.W.; Pierce, R.S.

    1968-01-01

    The forest of a small watershed-ecosystem was cut in order to determine the effects of removal of vegetation on nutrient cycles. Relative to undisturbed ecosystems, the cut ecosystem exhibited accelerated loss of nutrients: nitrogen lost during the first year after cutting was equivalent to the amount annually turned over in an undisturbed system, and losses of cations were 3 to 20 times greater than from comparable undisturbed systems. Possible causes of the pattern of nutrient loss from the cut ecosystem are discussed.

  20. Dust Emissions from Undisturbed and Disturbed, Crusted Playa Surfaces: Cattle Trampling Effect

    NASA Astrophysics Data System (ADS)

    Zobeck, T. M.; Baddock, M. C.; van Pelt, R.; Fredrickson, E. L.

    2009-12-01

    Dry playa lake beds can be a significant source of fine dust emissions during high wind events in arid and semiarid landscapes. The physical and chemical properties of the playa surface control the amount and properties of the dust emitted. In this study, we use a field wind tunnel to quantify the dust emissions from a bare, fine-textured playa surface located in the Chihuahua Desert at the Jornada Experimental Range, near Las Cruces, New Mexico, USA. We tested natural, undisturbed crusted surfaces and surfaces that had been subjected to two levels of domestic animal disturbance. The animal disturbance was provided by trampling produced from one and ten passes along the length of the wind tunnel by a 630 kg Angus-Hereford cross cow. The trampling broke the durable crust and created loose erodible material. Each treatment (natural crust, one pass, and ten passes) was replicated three times. A push-type wind tunnel with a 6 m long, 0.5 m wide, and 1 m high test section was used to generate dust emissions under controlled conditions. Clean medium sand was dropped onto the playa surface to act as an abrader material. The tunnel wind speed was equivalent to 15 m/s at a height of 2 m over a smooth soil surface. The tunnel was initially run for ten minutes, with no abrader added. A second 30 minute run was subsequently sampled as abrader was added to the wind stream. Dust and saltating material were collected using an isokinetic slot sampler at the end of the tunnel. Total airborne dust was collected on two 25 cm x 20 cm glass fiber filters (GFF) and measured using a GRIMM particle monitor every 6 sec throughout each test run. Disturbance by trampling generated increased saltating material and airborne dust. The amount of saltating material measured during the initial (no abrader added) run was approximately 70% greater and 5.8 times the amount of saltating material measured on the one pass and ten pass plots, respectively, compared with that observed on the undisturbed

  1. Signature-whistle production in undisturbed free-ranging bottlenose dolphins (Tursiops truncatus).

    PubMed Central

    Cook, Mandy L. H.; Sayigh, Laela S.; Blum, James E.; Wells, Randall S.

    2004-01-01

    Data from behavioural observations and acoustic recordings of free-ranging bottlenose dolphins (Tursiops truncatus) were analysed to determine whether signature whistles are produced by wild undisturbed dolphins, and how whistle production varies with activity and group size. The study animals were part of a resident community of bottlenose dolphins near Sarasota, Florida, USA. This community of dolphins provides a unique opportunity for the study of signature-whistle production, since most animals have been recorded during capture-release events since 1975. Three mother-calf pairs and their associates were recorded for a total of 141.25 h between May and August of 1994 and 1995. Whistles of undisturbed dolphins were compared with those recorded from the same individuals during capture-release events. Whistles were conservatively classified into one of four categories: signature, probable signature, upsweep or other. For statistical analyses, signature and probable signature whistles were combined into a 'signature' category; upsweep and other whistles were combined into a 'non-signature' category. Both 'signature' and 'non-signature' whistle frequencies significantly increased as group size increased. There were significant differences in whistle frequencies across activity types: both 'signature' and 'non-signature' whistles were most likely to occur during socializing and least likely to occur during travelling. There were no significant interactions between group size and activity type. Signature and probable signature whistles made up ca. 52% of all whistles produced by these free-ranging bottlenose dolphins. PMID:15293858

  2. Effects of geomagnetic activity in the winter thermosphere 1. Magnetically undisturbed conditions

    SciTech Connect

    Hagan, M.E.; Salah, J.E. )

    1988-09-01

    A two-part study of the influence of magnetic variability on the structure and dynamics of the winter thermosphere as observed by incoherent scatter radars has been conducted. Here, in paper 1, the authors present a thermospheric case study for magnetically undisturbed geophysical conditions, which is used as a reference in studying the magnetic storm effects in paper 2. Neutral exospheric temperatures derived from incoherent scatter radar measurements made at Millstone Hill (43{degree}N), Arecibo (18{degree}N), and Sondrestrom (67{degree}N) between January 14 and 17, 1986, serve as the control case. Mean temperatures and diurnal temperature variations resulting from Fourier decomposition of these data are compared with the predictions of the MSIS-86 model and recent theoretical calculations. These comparisons confirm the largely reliable predictive capabilities of the magnetically undisturbed winter thermosphere models, but point to some inconsistencies in the horizontal structure of diurnal temperature amplitudes between modeled and measured results. In particular, exospheric temperatures determined from Arecibo measurements appear to be suppressed with respect to both middle-latitude temperature determinations and the predictions of MSIS. A tidal analysis of neutral wind determinations from Millstone Hill measurements, however, reveals that middle-latitude meridional mean and diurnal flow was consistent with previous analogous results.

  3. Parasite load and MHC diversity in undisturbed and agriculturally modified habitats of the ornate dragon lizard.

    PubMed

    Radwan, Jacek; Kuduk, Katarzyna; Levy, Esther; LeBas, Natasha; Babik, Wiesław

    2014-12-01

    Major histocompatibility complex (MHC) gene polymorphism is thought to be driven by host-parasite co-evolution, but the evidence for an association between the selective pressure from parasites and the number of MHC alleles segregating in a population is scarce and inconsistent. Here, we characterized MHC class I polymorphism in a lizard whose habitat preferences (rock outcrops) lead to the formation of well-defined and stable populations. We investigated the association between the load of ticks, which were used as a proxy for the load of pathogens they transmit, and MHC class I polymorphism across populations in two types of habitat: undisturbed reserves and agricultural land. We hypothesized that the association would be positive across undisturbed reserve populations, but across fragmented agricultural land populations, the relationship would be distorted by the loss of MHC variation due to drift. After controlling for habitat, MHC diversity was not associated with tick number, and the habitats did not differ in this respect. Neither did we detect a difference between habitats in the relationship between MHC and neutral diversity, which was positive across all populations. However, there was extensive variation in the number of MHC alleles per individual, and we found that tick number was positively associated with the average number of alleles carried by lizards across reserve populations, but not across populations from disturbed agricultural land. Our results thus indicate that local differences in selection from parasites may contribute to MHC copy number variation within species, but habitat degradation can distort this relationship.

  4. Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches.

    PubMed

    Wagner, Elena L E S; Roche, Dominique G; Binning, Sandra A; Wismer, Sharon; Bshary, Redouan

    2015-01-01

    Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes), live coral cover and patch size (volume). The presence of the ectoparasite-eating cleaner wrasse, Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

  5. Infiltration characteristics of non-aqueous phase liquids in undisturbed loessal soil cores.

    PubMed

    Wang, Yunqiang; Shao, Ming'an

    2009-01-01

    The widespread contamination of soils and aquifers by non-aqueous phase liquids (NAPL), such as crude oil, poses serious environmental and health hazards globally. Understanding the infiltration characteristics of NAPL in soil is crucial in mitigating or remediating soil contamination. The infiltration characteristics of crude and diesel oils into undisturbed loessal soil cores, collected in polymethyl methacrylate cylindrical columns, were investigated under a constant fluid head (3 cm) of either crude oil or diesel oil. The infiltration rate of both crude and diesel oils decreased exponentially as wetting depth increased with time. Soil core size and bulk density both had significant effects on NAPL infiltration through the undisturbed soil cores; a smaller core size or a greater bulk density could reduce oil penetration to depth. Compacting soil in areas susceptible to oil spills may be an effective stratage to reduce contamination. The infiltration of NAPL into soil cores was spatially anisotropic and heterogeneous, thus recording the data at four points on the soil core is a good stratage to improve the accuracy of experimental results. Our results revealed that crude and diesel oils, rather than their components, have a practical value for remediation of contaminated loessal soils.

  6. Effects of forest fragmentation on phenological patterns and reproductive success of the tropical dry forest tree Ceiba aesculifolia.

    PubMed

    Herrerías-Diego, Yvonne; Quesada, Mauricio; Stoner, Kathryn E; Lobo, Jorge A

    2006-08-01

    Spatial isolation caused by forest fragmentation and temporal isolation caused by asynchronous flowering of plants have been proposed as important factors that affect the reproduction ofplant populations. In a 4-year study, we determined the effects of forest fragmentation and spatial isolation on flowering phenology and reproductive success of the tropical tree Ceiba aesculifolia ([Kunth] Britton & Rose). We conducted our study in the dry forest of Mexico and compared populations in two habitat conditions based on density and environmental conditions: (1) disturbed habitat (four populations of < or =3 reproductive individuals/ha surrounded by agriculturalfields or pastures) and (2) undisturbed habitat (three populations of groups of >6 reproductive individuals/ha surrounded by undisturbed mature forest). We compared the following variables within these populations over 4 years: flowering overlap, proportion of individuals with flowers and fruit, total flower production, total fruit production, fruit set, seed production, and seed abortion. Little overlap in flowering occurred among the populations in the two habitat conditions. The flowering period of trees in the disturbed habitat initiated between 15 to 20 days before the flowering period of trees in the undisturbed habitat during 3 years. Flowering of trees in the undisturbed habitat peaked at the end of the flowering period of the trees in the disturbed habitat. The proportion of trees that flowered was greater in the undisturbed habitat. Nevertheless, total flower production was greater in the disturbed habitat and these differences were maintained across 3 years. The proportion of individuals that produced fruit did not differ across habitat conditions but did differ across years. Total fruit production was greater in the disturbed habitat, but fruit set and seed production were the same across years and between habitat conditions. Seed abortion varied over years between habitats. We concluded that forest

  7. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    PubMed Central

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-01-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m−2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest. PMID:28186151

  8. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    NASA Astrophysics Data System (ADS)

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-02-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m‑2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest.

  9. Vertical distribution of soil removed by four species of burrowing rodents in disturbed and undisturbed soils

    SciTech Connect

    Reynolds, T.D.; Laundre, J.W.

    1988-04-01

    Burrow volumes were determined in disturbed and undisturbed soils for four species of rodents in southeastern Idaho. Comparisons were made between soil types for the average volume and the proportion of the total volume of soil excavated from 10-cm increments for each species, and the relative number of burrows and proportion of total soil removed from beneath the minimum thickness of soil covers over buried low-level radioactive wastes. Burrows of montane voles (Microtus montanus) and deer mice (Peromyscus maniculatus) rarely extended below 50 cm and neither volumes nor depths were influenced by soil disturbance. Townsend's ground squirrels (Spermophilus townsendii) had the deepest and most voluminous burrows that, along with Ord's kangaroo rat (Dipodomys ordii) burrows, were more prevalent beneath 50 cm in disturbed soils.

  10. Ecotoxicological risk assessment of undisturbed metal contaminated soil at two remote lighthouse sites.

    PubMed

    Chapman, E Emily V; Dave, Göran; Murimboh, John D

    2010-07-01

    Ecotoxicological risk assessments of contaminated soil are commonly completed using guideline values based on total concentrations. However, only certain fractions of contaminants are bioavailable and pose a hazard to the environment. This paper investigates the relationship between measured metal concentrations in soil and soil leachate, and the effects in organisms exposed to intact, undisturbed soil cores (wheat, Tricum aestivum) and soil leachate (lettuce, Lactuca sativa, and water flea, Daphnia magna). Despite the samples containing metal concentrations significantly above guideline values, metals of concern (e.g. Pb and Zn) did not have a significant toxic effect on wheat or D. magna. During weeks with low leachate pH, an effect on lettuce root elongation was observed in the most contaminated samples. This study has shown that bioassays with intact soil cores can indicate metal bioavailability and provide a better estimate of ecological risk than total metal concentrations in the soil.

  11. Anthropogenic lead distribution in rodent-affected and undisturbed soils in southern California

    SciTech Connect

    Mace, J.E.; Graham, R.C.; Amrhein, C.

    1997-01-01

    Anthropogenic Pb is the world`s largest and most widespread heavy metal contamination. Inspired by recent evidence suggesting a faster redistribution of Pb through the mineral soil profile than was previously expected, we investigated the effects of rodent activity on Pb redistribution. Total Pb was analyzed at the 0-1, 1-4, and 4-7-cm depths in a rodent-affected soil and in an undisturbed soil, in the same proximity and with the same parent material, in the Box Springs Mountains near Riverside, California. Six replicate sites of each condition were sampled. Lead was recovered by a digest in 4 M HNO{sub 3} and measured using a graphite furnace atomic absorption spectrophotometer. Anthropotenic Pb content to a 7-cm depth averaged 19 mg kg{sup -1} in undisturbed soils and 10 mg kg{sup -1} in rodent-affected soils. In both soils, the highest concentrations of Pb were located in the top 4 cm of the profile. After accounting for an estimated native Pb ({approximately}3.3 mg kg{sup -1}), we determined that 20 to 38 kg ha{sup -1} Pb has been deposited on these soils, through air pollution. Our findings suggest rodents significantly modify the distribution of anthropogenic Pb in the rodent-affected soils of the box Springs Mountains primarily in two ways: (i) by reducing Pb concentration in surface soils, thereby decreasing the potential for erosional redistribution of Pb, and (ii) by decreasing Pb transport time through the soil profile as a result of physical mixing. This redistribution mechanism is likely applicable to other surface deposited anthropogenic contaminants that have similarly low soil mobility. 18 refs., 1 fig., 2 tabs.

  12. The water balance components of undisturbed tropical woodlands in the Brazilian cerrado

    NASA Astrophysics Data System (ADS)

    Oliveira, P. T. S.; Wendland, E.; Nearing, M. A.; Scott, R. L.; Rosolem, R.; da Rocha, H. R.

    2015-06-01

    Deforestation of the Brazilian cerrado region has caused major changes in hydrological processes. These changes in water balance components are still poorly understood but are important for making land management decisions in this region. To better understand pre-deforestation conditions, we determined the main components of the water balance for an undisturbed tropical woodland classified as "cerrado sensu stricto denso". We developed an empirical model to estimate actual evapotranspiration (ET) by using flux tower measurements and vegetation conditions inferred from the enhanced vegetation index and reference evapotranspiration. Canopy interception, throughfall, stemflow, surface runoff, and water table level were assessed from ground measurements. We used data from two cerrado sites, Pé de Gigante (PDG) and Instituto Arruda Botelho (IAB). Flux tower data from the PDG site collected from 2001 to 2003 were used to develop the empirical model to estimate ET. The other hydrological processes were measured at the field scale between 2011 and 2014 at the IAB site. The empirical model showed significant agreement (R2 = 0.73) with observed ET at the daily timescale. The average values of estimated ET at the IAB site ranged from 1.91 to 2.60 mm day-1 for the dry and wet seasons, respectively. Canopy interception ranged from 4 to 20 % and stemflow values were approximately 1 % of the gross precipitation. The average runoff coefficient was less than 1 %, while cerrado deforestation has the potential to increase that amount up to 20-fold. As relatively little excess water runs off (either by surface water or groundwater), the water storage may be estimated by the difference between precipitation and evapotranspiration. Our results provide benchmark values of water balance dynamics in the undisturbed cerrado that will be useful to evaluate past and future land-cover and land-use changes for this region.

  13. Nitrogen transformations and greenhouse gas emissions from a riparian wetland soil: an undisturbed soil column study.

    PubMed

    Muñoz-Leoz, Borja; Antigüedad, Iñaki; Garbisu, Carlos; Ruiz-Romera, Estilita

    2011-01-15

    Riparian wetlands bordering intensively managed agricultural fields can act as biological filters that retain and transform agrochemicals such as nitrate and pesticides. Nitrate removal in wetlands has usually been attributed to denitrification processes which in turn imply the production of greenhouse gases (CO(2) and N(2)O). Denitrification processes were studied in the Salburua wetland (northern Spain) by using undisturbed soil columns which were subsequently divided into three sections corresponding to A-, Bg- and B2g-soil horizons. Soil horizons were subjected to leaching with a 200 mg NO₃⁻L⁻¹ solution (rate: 90 mL day⁻¹) for 125 days at two different temperatures (10 and 20°C), using a new experimental design for leaching assays which enabled not only to evaluate leachate composition but also to measure gas emissions during the leaching process. Column leachate samples were analyzed for NO₃⁻concentration, NH(4)(+) concentration, and dissolved organic carbon. Emissions of greenhouse gases (CO₂ and N₂O) were determined in the undisturbed soil columns. The A horizon at 20°C showed the highest rates of NO₃⁻ removal (1.56 mg N-NO₃⁻kg⁻¹ DW soil day⁻¹) and CO₂ and N₂O production (5.89 mg CO₂ kg⁻¹ DW soil day⁻¹ and 55.71 μg N-N₂O kg⁻¹ DW soil day⁻¹). For the Salburua wetland riparian soil, we estimated a potential nitrate removal capacity of 1012 kg N-NO₃⁻ha⁻¹ year⁻¹, and potential greenhouse gas emissions of 5620 kg CO₂ ha⁻¹ year⁻¹ and 240 kg N-N₂O ha⁻¹ year⁻¹.

  14. Volatile compounds released by disturbed and undisturbed adults of Anchomenus dorsalis (Coleoptera, Carabidae, Platynini) and structure of the pygidial gland

    PubMed Central

    Bonacci, Teresa; Brandmayr, Pietro; Zetto, Tullia; Perrotta, Ida Daniela; Guarino, Salvatore; Peri, Ezio; Colazza, Stefano

    2011-01-01

    Abstract Volatile compounds produced by adults of Anchomenus dorsalis under undisturbed and disturbed conditions were investigated with an all-glass aeration apparatus. GC-MS analysis of the crude extracts from undisturbed and disturbed adults highlighted four major volatile compounds, undecane, heneicosane, Z-9 tricosene and tricosane, of which significantly more undecane was released by disturbed adults compared to undisturbed beetles. The pygidial glands of adults of Anchomenus dorsalis were investigated using light and Transmission Electron Microscopy (TEM). Each gland showed dense aggregates of secretory cells organized into visually distinct lobes; a long collecting canal that drains the secretion towards the reservoir, a bean-shaped double lobed muscular reservoir in which secretion is stored and a short duct (efferent duct) through which the secretion is discharged. The function of the pygidial glands and the possible role played by undecane as a defensive allomone and/or chemical signalling molecule are discussed. PMID:21594158

  15. Organic matter and nutrient dynamics of the forest and forest floor in the Hubbard Brook forest.

    PubMed

    Gosz, James R; Likens, Gene E; Bormann, F Herbert

    1976-12-01

    The forest floor is a major reservoir of organic matter and nutrients for the ecosystem and as such it influences or regulates most of the functional processes occurring throughout the ecosystem. This study reports on the nutrient and organic matter content of the forest floor of the Hubbard Brook Experimental Forest during different seasons and attempts to correlate results from studies of vegetation, litter, decomposition, stemflow, throughfall, and soil. An organic matter budget is presented for an undisturbed watershed.Average weight of the forest floor on an undisturbed watershed ranged from 25,500 to 85,500 kg/ha. The weighted watershed average was 46,800 kg/ha. Although the F and H horizons did not vary significantly with time, the L horizon increased significantly during the period June to August largely as a result of a severe hail storm. The order of abundance of elements in the forest floor was Nτ;Ca≷Fe>S>P>Mn>K>Mg>Na>Zn>Cu. The concentrations of Ca, K, and Mn decreased with depth in the forest floor while N, P, S, Na, Fe, Zn, and Cu concentrations increased. N:P ratios were similar in decomposing leaf tissue, the forest floor, litterfall, and net stemflow plus throughfall suggesting a similar pattern of cycling. S was proportional to N and P in decomposing leaf tissue, the forest floor, and litterfall. Net stemflow and throughfall were affected by a relatively large input of SO4=-S from the atmosphere. Residence times for elements in the forest floor were affected by inputs other than litterfall (precipitation, stemflow, and throughfall). Calculation of residence times using all inputs caused smaller values than if litterfall alone was used. While all residence times were reduced, the major differences occurred for K, S, and Na. N and P showed relatively long residence times as a result of retranslocation and immobilization by decomposers. The slow turnover rate because of the strong demand and retention by all biota must account for the efficiency

  16. A Novel Tropical Dry Forests: A Response to Environmental Change.

    NASA Astrophysics Data System (ADS)

    Lugo, A. E.; Molina, S.

    2015-12-01

    Dry Forest environments are favorable to human settlement and activities, leading to deforestation, agricultural enterprises, land degradation, and abandonment. As a result, tropical dry forests are vulnerable and experience a high rate of cover loss, which often requires restoration activities. We have studied the natural regeneration of dry forests in Puerto Rico following a variety of human activities including farming, cattle pasturing, charcoal production, and human dwellings. Our results show a high level of forest resilience to anthropogenic disturbances but also a change of species composition relative to undisturbed native forests. This novelty of forest composition represents a natural response to environmental changes induced by human activity and pre-adapts forests to conditions in the Anthropocene.

  17. Micro-scale modelling of energy fluxes over a small Fluxnet forest site in Denmark

    NASA Astrophysics Data System (ADS)

    Sogachev, A.; Dellwik, E.; Boegh, E.

    2012-12-01

    Most forests, especially in Europe, are too small to fulfil strict fetch requirements associated with idealized flux observations in undisturbed, homogeneous flow. As a consequence of limited fetch, the flux measured above the canopy will often deviate from the source strength underlying the measurements. Since representative measurements focused on heterogeneous effects are scarce because of demanding experimental arrangements the numerical modelling are often recruited for analysis of these deviations. During the last years the atmospheric boundary layer (ABL) model SCADIS (scalar distribution model; Sogachev et al., 2002, Tellus 54B, 784-819) has been successfully applied especially in the region adjacent to a forest edge in order to improve flux data interpretation. Most of the analyses were done for the neutral case and in two-dimensional mode. When analyzing the effect of a forest edge on both flow and passive scalar properties, numerical studies showed that sources located on a soil surface are major contributors to wave-like flux behavior downwind of the leading edge, and that it is important to distinguish the effects of ground sources from those of the foliage. In the present work, we apply the SCADIS model with enhanced turbulence closure including buoyancy for investigation of the daily course of energy fluxes over patchy forested terrain in Denmark, where the model is used in three-dimensional mode. The modelling results (with 50 m horizontal resolution) are in good qualitative agreement with high-resolution (60 m and 120 m) remote-sensing data of the effective surface temperature of the area near the site in focus: the forested areas are colder in daytime and warmer in night time than surrounding open areas. In contrast to the remote sensing approach, SCADIS provides the information about spatial distribution of latent and sensible heat vertical fluxes in the whole ABL. Topography and forest edge effects result in vertical turbulent fluxes that

  18. Extreme late-summer drought causes neutral annual carbon balance in southwestern ponderosa pine forests and grasslands

    NASA Astrophysics Data System (ADS)

    Kolb, Thomas; Dore, Sabina; Montes-Helu, Mario

    2013-03-01

    We assessed the impacts of extreme late-summer drought on carbon balance in a semi-arid forest region in Arizona. To understand drought impacts over extremes of forest cover, we measured net ecosystem production (NEP), gross primary production (GPP), and total ecosystem respiration (TER) with eddy covariance over five years (2006-10) at an undisturbed ponderosa pine (Pinus ponderosa) forest and at a former forest converted to grassland by intense burning. Drought shifted annual NEP from a weak source of carbon to the atmosphere to a neutral carbon balance at the burned site and from a carbon sink to neutral at the undisturbed site. Carbon fluxes were particularly sensitive to drought in August. Drought shifted August NEP at the undisturbed site from sink to source because the reduction of GPP (70%) exceeded the reduction of TER (35%). At the burned site drought shifted August NEP from weak source to neutral because the reduction of TER (40%) exceeded the reduction of GPP (20%). These results show that the lack of forest recovery after burning and the exposure of undisturbed forests to late-summer drought reduce carbon sink strength and illustrate the high vulnerability of forest carbon sink strength in the southwest US to predicted increases in intense burning and precipitation variability.

  19. Bromus tectorum invasion alters nitrogen dynamics in an undisturbed arid grassland ecosystem

    USGS Publications Warehouse

    Sperry, L.J.; Belnap, J.; Evans, R.D.

    2006-01-01

    The nonnative annual grass Bromus tectorum has successfully replaced native vegetation in many arid and semiarid ecosystems. Initial introductions accompanied grazing and agriculture, making it difficult to separate the effects of invasion from physical disturbance. This study examined N dynamics in two recently invaded, undisturbed vegetation associations (C3 and C4). The response of these communities was compared to an invaded/disturbed grassland. The invaded/disturbed communities had higher surface NH4+ input in spring, whereas there were no differences for surface input of NO3-. Soil inorganic N was dominated by NH4+, but invaded sites had greater subsurface soil NO3-. Invaded sites had greater total soil N at the surface four years post-invasion in undisturbed communities, but total N was lower in the invaded/disturbed communities. Soil ??15N increased with depth in the noninvaded and recently invaded communities, whereas the invaded/disturbed communities exhibited the opposite pattern. Enriched foliar ??15N values suggest that Bromus assimilated subsurface NO3-, whereas the native grasses were restricted to surface N. A Rayleigh distillation model accurately described decomposition patterns in the noninvaded communities where soil N loss is accompanied by increasing soil ??15N; however, the invaded/disturbed communities exhibited the opposite pattern, suggesting redistribution of N within the soil profile. This study suggests that invasion has altered the mechanisms driving nitrogen dynamics. Bromus litter decomposition and soil NO3- concentrations were greater in the invaded communities during periods of ample precipitation, and NO3- leached from the surface litter, where it was assimilated by Bromus. The primary source of N input in these communities is a biological soil crust that is removed with disturbance, and the lack of N input by the biological soil crust did not balance N loss, resulting in reduced total N in the invaded/disturbed communities

  20. 3D-printing of undisturbed soil imaged by X-ray

    NASA Astrophysics Data System (ADS)

    Bacher, Matthias; Koestel, John; Schwen, Andreas

    2014-05-01

    The unique pore structures in Soils are altered easily by water flow. Each sample has a different morphology and the results of repetitions vary as well. Soil macropores in 3D-printed durable material avoid erosion and have a known morphology. Therefore potential and limitations of reproducing an undisturbed soil sample by 3D-printing was evaluated. We scanned an undisturbed soil column of Ultuna clay soil with a diameter of 7 cm by micro X-ray computer tomography at a resolution of 51 micron. A subsample cube of 2.03 cm length with connected macropores was cut out from this 3D-image and printed in five different materials by a 3D-printing service provider. The materials were ABS, Alumide, High Detail Resin, Polyamide and Prime Grey. The five print-outs of the subsample were tested on their hydraulic conductivity by using the falling head method. The hydrophobicity was tested by an adapted sessile drop method. To determine the morphology of the print-outs and compare it to the real soil also the print-outs were scanned by X-ray. The images were analysed with the open source program ImageJ. The five 3D-image print-outs copied from the subsample of the soil column were compared by means of their macropore network connectivity, porosity, surface volume, tortuosity and skeleton. The comparison of pore morphology between the real soil and the print-outs showed that Polyamide reproduced the soil macropore structure best while Alumide print-out was the least detailed. Only the largest macropore was represented in all five print-outs. Printing residual material or printing aid material remained in and clogged the pores of all print-out materials apart from Prime Grey. Therefore infiltration was blocked in these print-outs and the materials are not suitable even though the 3D-printed pore shapes were well reproduced. All of the investigated materials were insoluble. The sessile drop method showed angles between 53 and 85 degrees. Prime Grey had the fastest flow rate; the

  1. Imaging and quantification of preferential solute transport in an undisturbed soil

    NASA Astrophysics Data System (ADS)

    Koestel, John; Larsbo, Mats

    2014-05-01

    Despite significant advances during the last decades there are still many processes related to non-equilibrium flow and transport in macroporous soil that are far from being completely understood. The use of 3-D X-ray for imaging time-lapse 3-D solute transport has a large potential to help advance the knowledge in this field. We visualized the transport of a potassium iodide tracer (20 mg iodine ml-1 H2O) front through a small undisturbed soil column (height 3.8 cm, diameter 6.8 cm) under steady-state hydraulic conditions using an industrial X-ray scanner. Following an elaborate and time-costly illumination correction approach we yielded a series of seventeen 3-D difference images of density-changes with respect to the start of the tracer application. The spatial resolution was approximately 0.196 mm in all directions. The noise level varied between 3% and 8% of the maximally expected density changes. We related the time-lapse images to iodine concentrations using a linear calibration relationship. The electrical conductivity, assumed proportional to the iodide concentration, was measured in the effluent solution during the experiment. Eighty-five percent of the applied iodine mass was recovered in the effluent and inside the column. The solute transport through the soil predominantly took place within two cylindrical macropores, by-passing more than 90% of the bulk soil volume during the entire experiment. From these macropores the solute diffused into the surrounding soil matrix. We illustrated the properties of the investigated solute transport by comparing it to a 1-D convective-dispersive transport in terms of 1-D resident concentration profiles and to dilution indices, here used as estimates of preferential transport. We, furthermore, showed that the tracer diffusion from one of the macropores into the soil matrix could not be fitted with a cylindrical diffusion equation. We are positive that similar studies will help establishing links between soil

  2. Estimation of CO2 diffusion coefficient at 0-10 cm depth in undisturbed and tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diffusion coefficients (D) of CO2 at 0 – 10 cm layers in undisturbed and tilled soil conditions were estimated using Penman, Millington-Quirk, Ridgwell et al. (1999), Troeh et al., and Moldrup et al. models. Soil bulk density and volumetric soil water content ('v) at 0 – 10 cm were measured on April...

  3. Managing coarse woody debris in forests of the Rocky Mountains. Forest Service research paper

    SciTech Connect

    Graham, R.T.; Harvey, A.E.; Jurgensen, M.F.; Jain, T.B.; Tonn, J.R.

    1994-09-01

    Recommendations for managing coarse woody debris after timber harvest were developed for 14 habitat types, ranging from ponderosa pine (Pinus ponderosa) habitat types of Arizona to subalpine fir (Abis lasiocarpa) habitat types of western Montana. Ectomycorrhizae were used as a bioindicator of health, productive forest soils. Undisturbed stands were studied to determine the optimum amounts of organic material for ectomycorrhizal activity. The management recommendations are intentionally conservative to ensure that enough organic matter is left after timber harvest to maintain long-term forest productivity.

  4. Modeling fungicides mobility in undisturbed vineyard soil cores unamended and amended with spent mushroom substrates.

    PubMed

    Marín-Benito, Jesús María; Rodríguez-Cruz, María Sonia; Sánchez-Martín, María Jesús; Mamy, Laure

    2015-09-01

    The performance of the pesticide fate model PRZM to predict the fate of two fungicides, penconazole and metalaxyl, and the major metabolite of metalaxyl (CGA-62826), in amended and unamended vineyard soils was tested from undisturbed soils columns experiments. Three different treatments were tested in two soils: control soil (unamended), and soil amended with fresh or composted spent mushroom substrates, which correspond to common agricultural practices in Spain. Leaching experiments were performed under non-saturated flow conditions. The model was parameterized with laboratory and literature data, and using pedotransfer functions. It was first calibrated for water flow against chloride breakthrough curves. The key parameter was the hydrodynamic dispersion coefficient (DISP). No leaching of penconazole, the most hydrophobic fungicide, was observed. It remained in the top 0-8 cm of the column. In any case, simulations were highly correlated to the experimental results. On the contrary, metalaxyl and its metabolite were consistently found in the leachates. A calibration step of the Kd of metalaxyl and CGA-62826 and of DISP for CGA-62826 was necessary to obtain good prediction of the leaching of both compounds. PRZM generally simulated acceptable metalaxyl vertical distribution in the soil profiles although results were overestimated for its metabolite. Nevertheless, PRZM can be reasonably used to assess the leaching (through breakthrough curves) and vertical distribution of fungicides in amended soils, knowing their DISP values.

  5. Soil polarization data collected for the global undisturbed/disturbed Earth (GUIDE) program

    NASA Astrophysics Data System (ADS)

    Berry, Thomas E.; Lord, Elizabeth; Morgan, Cliff

    2016-05-01

    A key product of the global undisturbed/disturbed earth (GUIDE) program is the development of a soils database of broadband, hyperspectral, and polarized data. As a part of the GUIDE program, the U.S. Army Engineer Research and Development Center (ERDC) conducted a testing series involving a large variety of instrumentation at several sites at the Yuma Test Center (YTC) in fiscal year 2015 under the auspices of the Joint Improvised Explosive Device Defeat Organization (now the Joint Improvised-Threat Defeat Agency), generating approximately 17 terabytes of data. Most of this data, available through the ERDC, comprises hyperspectral polarimetric scientific data in the visible, near-infrared, shortwave infrared, and longwave infrared bands. As part of this testing series the performance of six handheld devices was characterized. We discuss the process of this data collection at YTC focusing on the polarimetric data, including the two handheld devices that relied on polarization for detection. Although some other polarization states discriminate soils better in some other wavelengths, for certain visible and near-infrared bands the Stokes S2 parameter provided the best discrimination.

  6. Resistance of Undisturbed Soil Microbiomes to Ceftriaxone Indicates Extended Spectrum β-Lactamase Activity

    PubMed Central

    Gatica, Joao; Yang, Kun; Pagaling, Eulyn; Jurkevitch, Edouard; Yan, Tao; Cytryn, Eddie

    2015-01-01

    Emergence and spread of antibiotic resistance, and specifically resistance to third generation cephalosporins associated with extended spectrum β-lactamase (ESBL) activity, is one of the greatest epidemiological challenges of our time. In this study we addressed the impact of the third generation cephalosporin ceftriaxone on microbial activity and bacterial community composition of two physically and chemically distinct undisturbed soils in highly regulated microcosm experiments. Surprisingly, periodical irrigation of the soils with clinical doses of ceftriaxone did not affect their microbial activity; and only moderately impacted the microbial diversity (α and β) of the two soils. Corresponding slurry experiments demonstrated that the antibiotic capacity of ceftriaxone rapidly diminished in the presence of soil, and ∼70% of this inactivation could be explained by biological activity. The biological nature of ceftriaxone degradation in soil was supported by microcosm experiments that amended model Escherichia coli strains to sterile and non-sterile soils in the presence and absence of ceftriaxone and by the ubiquitous presence of ESBL genes (blaTEM, blaCTX-M, and blaOXA) in soil DNA extracts. Collectively, these results suggest that the resistance of soil microbiomes to ceftriaxone stems from biological activity and even more, from broad-spectrum β-lactamase activity; raising questions regarding the scope and clinical implications of ESBLs in soil microbiomes. PMID:26617578

  7. Measurement of effective air diffusion coefficients for trichloroethene in undisturbed soil cores.

    PubMed

    Bartelt-Hunt, Shannon L; Smith, James A

    2002-06-01

    In this study, we measure effective diffusion coefficients for trichloroethene in undisturbed soil samples taken from Picatinny Arsenal, New Jersey. The measured effective diffusion coefficients ranged from 0.0053 to 0.0609 cm2/s over a range of air-filled porosity of 0.23-0.49. The experimental data were compared to several previously published relations that predict diffusion coefficients as a function of air-filled porosity and porosity. A multiple linear regression analysis was developed to determine if a modification of the exponents in Millington's [Science 130 (1959) 100] relation would better fit the experimental data. The literature relations appeared to generally underpredict the effective diffusion coefficient for the soil cores studied in this work. Inclusion of a particle-size distribution parameter, d10, did not significantly improve the fit of the linear regression equation. The effective diffusion coefficient and porosity data were used to recalculate estimates of diffusive flux through the subsurface made in a previous study performed at the field site. It was determined that the method of calculation used in the previous study resulted in an underprediction of diffusive flux from the subsurface. We conclude that although Millington's [Science 130 (1959) 100] relation works well to predict effective diffusion coefficients in homogeneous soils with relatively uniform particle-size distributions, it may be inaccurate for many natural soils with heterogeneous structure and/or non-uniform particle-size distributions.

  8. Measurement of effective air diffusion coefficients for trichloroethene in undisturbed soil cores

    NASA Astrophysics Data System (ADS)

    Bartelt-Hunt, Shannon L.; Smith, James A.

    2002-06-01

    In this study, we measure effective diffusion coefficients for trichloroethene in undisturbed soil samples taken from Picatinny Arsenal, New Jersey. The measured effective diffusion coefficients ranged from 0.0053 to 0.0609 cm 2/s over a range of air-filled porosity of 0.23-0.49. The experimental data were compared to several previously published relations that predict diffusion coefficients as a function of air-filled porosity and porosity. A multiple linear regression analysis was developed to determine if a modification of the exponents in Millington's [Science 130 (1959) 100] relation would better fit the experimental data. The literature relations appeared to generally underpredict the effective diffusion coefficient for the soil cores studied in this work. Inclusion of a particle-size distribution parameter, d10, did not significantly improve the fit of the linear regression equation. The effective diffusion coefficient and porosity data were used to recalculate estimates of diffusive flux through the subsurface made in a previous study performed at the field site. It was determined that the method of calculation used in the previous study resulted in an underprediction of diffusive flux from the subsurface. We conclude that although Millington's [Science 130 (1959) 100] relation works well to predict effective diffusion coefficients in homogeneous soils with relatively uniform particle-size distributions, it may be inaccurate for many natural soils with heterogeneous structure and/or non-uniform particle-size distributions.

  9. Evaluation of bioventing on a gasoline-ethanol contaminated undisturbed residual soil.

    PubMed

    Osterreicher-Cunha, Patricia; Vargas, Eurípedes do Amaral; Guimarães, Jean Rémy Davée; de Campos, Tácio Mauro Pereira; Nunes, Cassiane Maria Ferreira; Costa, Ariovaldo; Antunes, Franklin dos Santos; da Silva, Maria Isabel Pais; Mano, Denise Maria

    2004-07-05

    Remediation methods for environmental contamination problems based on physical or chemical processes frequently present low efficiency and/or high costs. On the other hand, biological treatment is being proved to be an accessible alternative for soil and water remediation. Bioventing is commonly used for petroleum hydrocarbon (PHC) spills. This process provides better subsurface oxygenation, thus stimulating degradation by indigenous microorganisms. In Brazil, gasoline and ethanol are routinely mixed; some authors suggest that despite gasoline high degradability, its degradation in the aquifer is hindered by the presence of much rapidly degrading ethanol. The present study evaluates a bioventing treatment of a gasoline-ethanol contaminated undisturbed residual soil from Rio de Janeiro. Contamination and treatment effects were monitored by conventional microbiology methods, chemical analysis, and ground penetrating radar (GPR) measurements. Results of culturable bacterial population counts show the effect of contamination and bioventing on the microbiota of gasoline and gasoline-ethanol containing soils; however, GPR responses to these variations are not conclusive and still need to be assessed.

  10. Responses of Isolated Wetland Herpetofauna to Upland Forest Management

    SciTech Connect

    Russell, K.R.; Hanlin, H.G.; Wigley, T.B.; Guynn, D.C., Jr.

    2002-01-02

    Measurement of responses of herpetofauna at isolated wetlands in the Coastal Plain of South Carolina to disturbance of adjacent loblolly pine forest. Many species of isolated wetland herpetofauna in the Southeastern Coastal Plain may tolerate some disturbance in adjacent upland stands. Responses of isolated wetland herpetofauna to upland silviculture and the need for adjacent forested buffers likely depend on the specific landscape context in which the wetlands occur and composition of the resident herpetofaunal community.

  11. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  12. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  13. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  14. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  15. Compaction of forest soil by logging machinery favours occurrence of prokaryotes.

    PubMed

    Schnurr-Pütz, Silvia; Bååth, Erland; Guggenberger, Georg; Drake, Harold L; Küsel, Kirsten

    2006-12-01

    Soil compaction caused by passage of logging machinery reduces the soil air capacity. Changed abiotic factors might induce a change in the soil microbial community and favour organisms capable of tolerating anoxic conditions. The goals of this study were to resolve differences between soil microbial communities obtained from wheel-tracks (i.e. compacted) and their adjacent undisturbed sites, and to evaluate differences in potential anaerobic microbial activities of these contrasting soils. Soil samples obtained from compacted soil had a greater bulk density and a higher pH than uncompacted soil. Analyses of phospholipid fatty acids demonstrated that the eukaryotic/prokaryotic ratio in compacted soils was lower than that of uncompacted soils, suggesting that fungi were not favoured by the in situ conditions produced by compaction. Indeed, most-probable-number (MPN) estimates of nitrous oxide-producing denitrifiers, acetate- and lactate-utilizing iron and sulfate reducers, and methanogens were higher in compacted than in uncompacted soils obtained from one site that had large differences in bulk density. Compacted soils from this site yielded higher iron-reducing, sulfate-reducing and methanogenic potentials than did uncompacted soils. MPN estimates of H2-utilizing acetogens in compacted and uncompacted soils were similar. These results indicate that compaction of forest soil alters the structure and function of the soil microbial community and favours occurrence of prokaryotes.

  16. Forest Management.

    ERIC Educational Resources Information Center

    Weicherding, Patrick J.; And Others

    This bulletin deals with forest management and provides an overview of forestry for the non-professional. The bulletin is divided into six sections: (1) What Is Forestry Management?; (2) How Is the Forest Measured?; (3) What Is Forest Protection?; (4) How Is the Forest Harvested?; (5) What Is Forest Regeneration?; and (6) What Is Forest…

  17. Logging affects fledgling sex ratios and baseline corticosterone in a forest songbird.

    PubMed

    Leshyk, Rhiannon; Nol, Erica; Burke, Dawn M; Burness, Gary

    2012-01-01

    Silviculture (logging) creates a disturbance to forested environments. The degree to which forests are modified depends on the logging prescription and forest stand characteristics. In this study we compared the effects of two methods of group-selection ("moderate" and "heavy") silviculture (GSS) and undisturbed reference stands on stress and offspring sex ratios of a forest interior species, the Ovenbird (Seiurus aurocapilla), in Algonquin Provincial Park, Canada. Blood samples were taken from nestlings for corticosterone and molecular sexing. We found that logging creates a disturbance that is stressful for nestling Ovenbirds, as illustrated by elevated baseline corticosterone in cut sites. Ovenbirds nesting in undisturbed reference forest produce fewer male offspring per brood (proportion male = 30%) while logging with progressively greater forest disturbance, shifted the offspring sex ratio towards males (proportion male: moderate = 50%, heavy = 70%). If Ovenbirds in undisturbed forests usually produce female-biased broods, then the production of males as a result of logging may disrupt population viability. We recommend a broad examination of nestling sex ratios in response to anthropogenic disturbance to determine the generality of our findings.

  18. Logging Affects Fledgling Sex Ratios and Baseline Corticosterone in a Forest Songbird

    PubMed Central

    Leshyk, Rhiannon; Nol, Erica; Burke, Dawn M.; Burness, Gary

    2012-01-01

    Silviculture (logging) creates a disturbance to forested environments. The degree to which forests are modified depends on the logging prescription and forest stand characteristics. In this study we compared the effects of two methods of group-selection (“moderate” and “heavy”) silviculture (GSS) and undisturbed reference stands on stress and offspring sex ratios of a forest interior species, the Ovenbird (Seiurus aurocapilla), in Algonquin Provincial Park, Canada. Blood samples were taken from nestlings for corticosterone and molecular sexing. We found that logging creates a disturbance that is stressful for nestling Ovenbirds, as illustrated by elevated baseline corticosterone in cut sites. Ovenbirds nesting in undisturbed reference forest produce fewer male offspring per brood (proportion male = 30%) while logging with progressively greater forest disturbance, shifted the offspring sex ratio towards males (proportion male: moderate = 50%, heavy = 70%). If Ovenbirds in undisturbed forests usually produce female-biased broods, then the production of males as a result of logging may disrupt population viability. We recommend a broad examination of nestling sex ratios in response to anthropogenic disturbance to determine the generality of our findings. PMID:22432000

  19. Water and solute mass balance of five small, relatively undisturbed watersheds in the U.S.

    USGS Publications Warehouse

    Peters, N.E.; Shanley, J.B.; Aulenbach, Brent T.; Webb, R.M.; Campbell, D.H.; Hunt, R.; Larsen, M.C.; Stallard, R.F.; Troester, J.; Walker, J.F.

    2006-01-01

    Geochemical mass balances were computed for water years 1992-1997 (October 1991 through September 1997) for the five watersheds of the U.S. Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) Program to determine the primary regional controls on yields of the major dissolved inorganic solutes. The sites, which vary markedly with respect to climate, geology, physiography, and ecology, are: Allequash Creek, Wisconsin (low-relief, humid continental forest); Andrews Creek, Colorado (cold alpine, taiga/tundra, and subalpine boreal forest); Ri??o Icacos, Puerto Rico (lower montane, wet tropical forest); Panola Mountain, Georgia (humid subtropical piedmont forest); and Sleepers River, Vermont (humid northern hardwood forest). Streamwater output fluxes were determined by constructing empirical multivariate concentration models including discharge and seasonal components. Input fluxes were computed from weekly wet-only or bulk precipitation sampling. Despite uncertainties in input fluxes arising from poorly defined elevation gradients, lack of dry-deposition and occult-deposition measurements, and uncertain sea-salt contributions, the following was concluded: (1) for solutes derived primarily from rock weathering (Ca, Mg, Na, K, and H4SiO4), net fluxes (outputs in streamflow minus inputs in deposition) varied by two orders of magnitude, which is attributed to a large gradient in rock weathering rates controlled by climate and geologic parent material; (2) the net flux of atmospherically derived solutes (NH4, NO3, SO4, and Cl) was similar among sites, with SO4 being the most variable and NH4 and NO3 generally retained (except for NO 3 at Andrews); and (3) relations among monthly solute fluxes and differences among solute concentration model parameters yielded additional insights into comparative biogeochemical processes at the sites. ?? 2005 Elsevier B.V. All rights reserved.

  20. Study of the transport of cadusafos in two tropical undisturbed soil columns

    NASA Astrophysics Data System (ADS)

    Dionisio Fernandez-Bayo, Jesus; Crevoisier, David; Saison, Carine; Geniez, Chantal; Huttel, Olivier; Samouelian, Anatja; Voltz, Marc

    2013-04-01

    The use of pesticides to control agriculture pests is a common practice on most tropical plantations whose vulnerability to pesticide pollution is very important due to the frequent heavy rains that wash pesticides from target areas. Tropical volcanic soils have been scarcely investigated in this sense and monitoring the dynamic of pesticide at column scale is of great interest for a better understanding at catchment scale and risk modelling. The objective was to study and model the transport of cadusafos (CDS) in two undisturbed soil columns from a nitisol and an andosol, representative of the major soils in agricultural areas of the FWI. Undisturbed soil columns from andosol (sandy-loam soil) and nitisol (clay soil) from Guadeloupe Island were spiked with 14C-CDS along with 10 g of granulate Rugby®. To each soil column, 10 rain events of different intensities (20 and 40 mm/h during 4 and 2 hours, respectively) were applied with 4-7 days delay between two subsequent rain events. For the nitisol columns, the cumulated rain was halved (by decreasing duration of each rain event) since these soils occur in drier areas of Guadeloupe and because the imposed rain intensities led to the accumulation of water at the surface of the column. At the end of the leaching experiment the extractable and non-extractable remaining pesticide residues were determined along the soil profile. The andosol presented a very high permeability attributed to the preferential flow expected in this type of soil with high macroporosity due to the allophane materials. The maximum concentration of CDS was attained during the first rainfall event while the cumulated infiltrated volume of water was much less than the pore volume of the column soil. The peak concentration levels of CDS were almost constant during the first 5 rain events and they decreased during the subsequent rain events, probably due to degradation and/or ageing processes of CDS. The nitisol showed lower permeability reflected in

  1. Dust emissions from undisturbed and disturbed, crusted playa surfaces: Cattle trampling effects

    NASA Astrophysics Data System (ADS)

    Baddock, Matthew C.; Zobeck, Ted M.; Van Pelt, R. Scott; Fredrickson, Ed L.

    2011-06-01

    Dry playa lake beds can be significant sources of fine dust emission. This study used a portable field wind tunnel to quantify the PM 10 emissions from a bare, fine-textured playa surface located in the far northern Chihuahua Desert. The natural, undisturbed crust and its subjection to two levels of animal disturbance (one and ten cow passes) were tested. The wind tunnel generated dust emissions under controlled conditions for firstly an initial blow-off of the surface, followed by two longer runs with sand added to the flow as an abrader material. Dust was measured using a GRIMM particle monitor. For the study playa, no significant differences in PM 10 concentration and emission flux were found between the untrampled surface and following a single animal pass. This was the case for both the initial blow-offs and tests on plots under a steady abrader rate. Significantly higher dust loading was only associated with the effect of 10 animal passes. In the blow-offs, the higher PM 10 yield after 10 passes reflected the greater availability of easily entrainable fine particles. Under abrasion, the effect of the heaviest trampling increased the emission flux by a third and abrasion efficiency by around 50% more than values on the untrampled surface. This enhanced abrasion efficiency persisted for a 30 min period under abrasion before the positive effect of the disturbance was no longer evident. The findings highlight the role of a threshold of disturbance that determines if supply-limited surfaces will exhibit enhanced wind erosion or not after undergoing perturbation.

  2. Constructing vegetation productivity equations by employing undisturbed soils data: An Oliver County, North Dakota case study

    SciTech Connect

    Burley, J.B.; Polakowski, K.J.; Fowler, G.

    1996-12-31

    Surface mine reclamation specialists have been searching for predictive methods to assess the capability of disturbed soils to support vegetation growth. We conducted a study to develop a vegetation productivity equation for reclaiming surface mines in Oliver County, North Dakota, thereby allowing investigators to quantitatively determine the plant growth potential of a reclaimed soil. The study examined the predictive modeling potential for both agronomic crops and woody plants, including: wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oat (Avena sativa L.), corn (Zea mays L.), grass and legume mixtures, Eastern red cedar (Juniperus virginiana L.), Black Hills spruce (Picea glauca var. densata Bailey), Colorado spruce (Picea pungens Engelm.), ponderosa pine (Pinus ponderosa var. scope Engelm.), green ash (Fraxinus pennsylvanica Marsh.), Eastern cottonwood Populus deltoides (Bart. ex Marsh.), Siberian elm (Ulmus pumila L.), Siberian peashrub (Caragana arborescens Lam), American plum (Prunus americans Marsh.), and chokecherry ( Prunus virginiana L.). An equation was developed which is highly significant (p<0.0001), explaining 81.08% of the variance (coefficient of multiple determination=0.8108), with all regressors significant (p{le}0.048, Type II Sums of Squares). The measurement of seven soil parameters are required to predict soil vegetation productivity: percent slope, available water holding capacity, percent rock fragments, topographic position, electrical conductivity, pH, and percent organic matter. While the equation was developed from data on undisturbed soils, the equation`s predictions were positively correlated (0.71424, p{le}0.0203) with a small data set (n=10) from reclaimed soils.

  3. Use of limestone karst forests by Bornean orangutans (Pongo pygmaeus morio) in the Sangkulirang peninsula, east Kalimantan, Indonesia.

    PubMed

    Marshall, Andrew J; Salas, Leonardo A; Stephens, Suzette; Engström, Linda; Meijaard, Erik; Stanley, Scott A

    2007-02-01

    The Indonesian province of East Kalimantan is home to some of the largest remaining contiguous tracts of lowland Dipterocarp forest on the island of Borneo. Nest surveys recently conducted in these forests indicated the presence of a substantial population of Eastern Bornean orangutans (Pongo pygmaeus morio) in the Berau and East Kutai regencies in the northern half of the province. The Sangkulirang Peninsula contains extensive limestone karst forests in close proximity to the lowland Dipterocarp forests inhabited by orangutans in these regencies. Orangutans have been sighted in these limestone karst forests, but the importance of this forest type for orangutans has been unclear. Therefore, we conducted 49 km of nest surveys in limestone karst forest to obtain the first quantitative estimates of orangutan densities in this habitat, and walked 28 km of surveys in nearby lowland Dipterocarp forests for comparison. We also gathered basic ecological data along our transects in an attempt to identify correlates of orangutan abundance across these habitat types. Undisturbed limestone karst forests showed the lowest orangutan densities (147 nests/km(2), 0.82 indiv/km(2)), disturbed limestone forests had intermediate densities (301 nests/km(2), 1.40 indiv/km(2)), and undisturbed lowland Dipterocarp forests contained the highest density (987 nests/km(2), 5.25 indiv/km(2)), significantly more than the undisturbed limestone karst forests. This difference was not correlated with variation in liana abundance, fig stem density, or stump density (an index of forest disturbance). Therefore, other factors, such as the relatively low tree species diversity of limestone karst forests, may explain why orangutans appear to avoid these areas. We conclude that limestone karst forests are of low relevance for safeguarding the future of orangutans in East Kalimantan.

  4. Vegetation recovery on closed paths in temperate deciduous forests.

    PubMed

    Roovers, Pieter; Bossuyt, Beatrijs; Gulinck, Hubert; Hermy, Martin

    2005-02-01

    The objective of this study was to evaluate vegetation recovery on footpaths in woodland that have been closed for access for 6 years. A vegetation survey was conducted in four mesophile forests, in transects perpendicular to the trail. Analyses concentrated on the direction and rate of the recovery process. Vegetation on trail sides in these ecosystems recovered substantially. Non-metric multidimensional scaling based upon species composition separated the four sample locations and each cluster contained representatives of the three major trail zones: path centre, transition and undisturbed zones. Analysis of distribution of life forms, plant strategies and seedbank longevity indices showed no differences between trail zones. This indicates that vegetation on the path centre is likely to recover towards the plant composition of the undisturbed zone. Ellenberg values indicate that environmental variation is not related to former path structures, as significant variability was only observed between the forest sites. Furthermore, the analysis concentrated on characteristics of species relevant to the recovery process.

  5. Mixed-Forest Species Establishment in a Monodominant Forest in Central Africa: Implications for Tropical Forest Invasibility

    PubMed Central

    Peh, Kelvin S.-H.; Sonké, Bonaventure; Séné, Olivier; Djuikouo, Marie-Noël K.; Nguembou, Charlemagne K.; Taedoumg, Hermann; Begne, Serge K.; Lewis, Simon L.

    2014-01-01

    Background Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. Methodology/Principal Findings We sampled all trees (diameter in breast height [dbh]≥10 cm) within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450–800 m apart). Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement–revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. Conclusions/Significance Our results suggest that certain traits (wood density and light requirement) and population-level characteristics (relative abundance) may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species. PMID:24844914

  6. Non-steady State Soil Organic Carbon Storage in Undisturbed Watersheds Due to Diffusive Sediment Transport

    NASA Astrophysics Data System (ADS)

    Yoo, K.; Amundson, R.; Heimsath, A. M.; Dietrich, W. E.

    2003-12-01

    Most soil C models assume that plant C inputs are matched by C loss through heterotrophic respiration. While these models are applicable for level terrain, on soil mantled uplands in hilly to mountainous regions, persistent soil mass transport represents a potentially large, but unstudied, flux of soil C. In this research we quantify the soil C erosional fluxes and non-steady state soil C storage within two undisturbed grass-covered hillslopes in Coastal California: Tennessee Valley (TV) (coastal Marin County) and Black Diamond (BD) (interior Contra Costa County). At both sites, previous geomorphic studies have quantified both the sediment transport processes (TV= gopher driven sediment transport; BD= abiotic soil shrink/swell) and their rates. Hillslope patterns of soil C storage were examined in relation to slope position with a hillslope sediment transport model. The average C erosion rates from convex slopes are between 1.4 and 2.7 g C m -2 yr-1 at TV and approximately 8 g C m-2 yr-1 at BD. The C erosional flux is locally as high as 14% of above ground net primary productivity (NPP) at TV and 8% at BD. The convex slopes are net C sinks because NPP likely exceeds respiration by a value equaling the size of C erosion. Eroded soils ultimately accumulate in depositional settings which have residence times on the order of 13kyrs at TV and 5.3kyrs at BD. At TV hollow, 15-24 kg C m-2 of soil C has accumulated at a long-term rate of 1.6-1.9 g C m-2 yr-1 . The present rates of C accumulation were calculated to be 0.3 g C m-2 yr-1 at TV and 0.6 g C m-2 yr-1 at BD. During the hollow infilling, the depositional C inputs have been greater than C accumulation rates, meaning that much of the incoming eroded C is ultimately oxidized to CO2. At both sites, a fraction of the eroded C is exported from the watershed (C of 0.1-0.5 g C m-2 yr-1 at TV and 2 g C m-2 yr-1 at BD). When all hillslope components are integrated, these watersheds are continuous atmospheric C sinks at rates

  7. Simazine transport in undisturbed soils from a vineyard at the Casablanca valley, Chile.

    PubMed

    Suárez, Francisco; Guzmán, Edwin; Muñoz, José F; Bachmann, Jaime; Ortiz, Cristian; Alister, Claudio; Kogan, Marcelo

    2013-03-15

    Simazine is a soil-active herbicide that has been applied worldwide in agricultural soils, being the second most commonly detected herbicide in groundwater and surface waters. Although its use has been restricted in many countries of Europe, it is still applied in many locations around the world in orchards, vineyards and forestry. Therefore, it is important to study its fate and transport in the environment. This paper investigates simazine transport in undisturbed bare soils from a vineyard at the Casablanca valley, Chile. In the study site, shallow groundwater tables (<1.0 m depth) and high simazine levels (>15 μg L(-1)) in the groundwater were observed and thus, there is potential for simazine to be transported further away through the saturated zone. The soils from the study site were characterized and the hydrodynamic transport parameters were determined. Column leaching experiments showed that the two-site chemical non-equilibrium model correctly represented simazine transport. It was found that 36.3% of the adsorption sites achieve instantaneous equilibrium and that the first-order kinetic rate of the non-equilibrium sites was 6.2 × 10(-3) h(-1). Hydrus 2D was used to predict the transport of simazine in the study site under natural field conditions. Simulation results showed that simazine concentrations at depths shallower than 2.1 m are above the maximum contaminant level of 4 μg L(-1) (defined by the U.S. Environmental Protection Agency). The timing of herbicide application was found to be important on simazine leaching and the main processes involved in simazine transport were degradation and adsorption, which accounted for 95.78 and 4.19% of the simulated mass of pesticide, respectively. A qualitative agreement in the timing and magnitude of simazine concentration was obtained between the simulations and the field data. Therefore, the model utilized in this investigation can be used to predict simazine transport and is a valuable tool to

  8. 75 FR 69619 - East Reservoir Project; Kootenai National Forest, Lincoln County, MT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Forest Service East Reservoir Project; Kootenai National Forest, Lincoln County, MT AGENCY: Forest Service, USDA. ACTION: Notice of intent to prepare an Environmental Impact Statement. SUMMARY: The Forest... prescribed fire, trail access management changes, and treatment of fuel adjacent to private property....

  9. Comparison of Storm-Generated Sediment Concentrations and Loads in an Urban Disturbed Basin and a Rural Undisturbed Basin, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Gellis, A. C.

    2002-05-01

    The factors controlling storm-generated suspended-sediment loads and concentrations were examined for two basins of contrasting land use in Puerto Rico from 1989 to 1995. The Quebrada Blanca Basin (8.39 km2), a relatively undisturbed basin, drains pasture (54%), forest (21%), cropland (8%), and rural (15%). The Rio Piedras Basin (19.4 km2) is 73% urban and is considered disturbed because of extensive urbanization in the remaining 23% forested areas of the basin, involving many construction projects that expose bare soil. Twenty-three runoff events, defined by a peak over 0.42 m3/s, were examined in Quebrada Blanca and 26 events, defined by a peak over 1.4 m3/s, were examined in Rio Piedras. Three dependent factors were used to describe suspended-sediment transport: (1) suspended-sediment load, (2) discharge-weighted sediment concentration, and (3) time-weighted sediment concentration. Thirteen independent factors controlling sediment were delineated into three time categories: (1) characteristics of the previous event, (2) characteristics between events, and (3) characteristics of the current event. The dependent and independent factors were separated into quickflow and total runoff to determine if one was more significant in explaining sediment. Forward stepwise regression analysis for Quebrada Blanca showed that the most significant variables explaining sediment load and concentrations were directly correlated to the characteristics of the current storm event (for both the quickflow and total runoff aspects of the hydrographs). These included the total quickflow, sum of peak flows, and maximum rate of hydrograph rise for any peak. In Rio Piedras, the three dependent variables for both aspects of the hydrograph were inversely correlated to the rainfall since the previous runoff event. These are smaller rainfall totals that do not cause significant increases in streamflow but are flushing sediment from the system that would be available for the current sampled

  10. Two-stage recovery of amphibian assemblages following selective logging of tropical forests.

    PubMed

    Adum, Gilbert Baase; Eichhorn, Markus Peter; Oduro, William; Ofori-Boateng, Caleb; Rödel, Mark-Oliver

    2013-04-01

    There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian

  11. Characteristics of histamine-induced leukocyte rolling in the undisturbed microcirculation of the rat mesentery

    PubMed Central

    Yamaki, Kohji; Thorlacius, Henrik; Xie, Xun; Lindbom, Lennart; Hedqvist, Per; Raud, Johan

    1998-01-01

    The main objective of this study was to analyse the role and mode of action of the mast cell mediator histamine in leukocyte-endothelium interactions in small venules in vivo. For this purpose, we used a histological approach (combined with intravital microscopy) that allows studies of rapid mediator-induced venular leukocyte accumulation, reflecting leukocyte rolling, in the undisturbed microcirculation of the rat mesentery where rolling is normally absent. We first examined the relative importance of histamine and 5-hydroxytryptamine (5-HT) in acute mast cell-dependent leukocyte recruitment. The mast cell secretagogue compound 48/80 (i.p. for 15 min) induced a marked venular accumulation of polymorphonuclear leukocytes (PMNL) which was almost abolished by combined histamine1 (H1)- and histamine2 (H2)-receptor blockade. In contrast, the 5-HT-receptor antagonist methysergide was inactive in this regard. Moreover, exogenous 5-HT was less active than exogenous histamine in evoking venular PMNL accumulation (histamine response dose-dependent; 5-HT response bell shaped). Prostaglandin D2 did not cause PMNL accumulation. The venular PMNL response to exogenous histamine peaked between 15 min and 1 h, was still significantly elevated at 2 h, and then returned to prechallenge values after 3 h. At all time points, the histamine-induced PMNL accumulation was nearly abolished by i.v. treatment with the polysaccharide fucoidin (which blocks rolling but not firm adhesion per se), suggesting that the PMNL response to histamine was due to rolling rather than firm adhesion over the entire 3 h period. At no time point did histamine trigger accumulation of mononuclear leukocytes (MNL). To examine the role of histamine-receptors in the histamine-induced PMNL accumulation (i.e. rolling), the animals were pretreated with diphenhydramine (H1-receptor antagonist), cimetidine, or ranitidine (H2-receptor antagonists). Diphenhydramine alone inhibited the venular PMNL response to

  12. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  13. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  14. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  15. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  16. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  17. Primary forests are irreplaceable for sustaining tropical biodiversity.

    PubMed

    Gibson, Luke; Lee, Tien Ming; Koh, Lian Pin; Brook, Barry W; Gardner, Toby A; Barlow, Jos; Peres, Carlos A; Bradshaw, Corey J A; Laurance, William F; Lovejoy, Thomas E; Sodhi, Navjot S

    2011-09-14

    Human-driven land-use changes increasingly threaten biodiversity, particularly in tropical forests where both species diversity and human pressures on natural environments are high. The rapid conversion of tropical forests for agriculture, timber production and other uses has generated vast, human-dominated landscapes with potentially dire consequences for tropical biodiversity. Today, few truly undisturbed tropical forests exist, whereas those degraded by repeated logging and fires, as well as secondary and plantation forests, are rapidly expanding. Here we provide a global assessment of the impact of disturbance and land conversion on biodiversity in tropical forests using a meta-analysis of 138 studies. We analysed 2,220 pairwise comparisons of biodiversity values in primary forests (with little or no human disturbance) and disturbed forests. We found that biodiversity values were substantially lower in degraded forests, but that this varied considerably by geographic region, taxonomic group, ecological metric and disturbance type. Even after partly accounting for confounding colonization and succession effects due to the composition of surrounding habitats, isolation and time since disturbance, we find that most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity. Our results clearly indicate that when it comes to maintaining tropical biodiversity, there is no substitute for primary forests.

  18. Effect of rhizobacterial consortia from undisturbed arid- and agro-ecosystems on wheat growth under different conditions.

    PubMed

    Inostroza, N G; Barra, P J; Wick, L Y; Mora, M L; Jorquera, M A

    2017-02-01

    Plant growth-promoting rhizobacteria (PGPR) are studied as complements/alternatives to chemical fertilizers used in agriculture. However, poor information exists on the potential of PGPR from undisturbed ecosystems. Here, we have evaluated the plant growth-promoting (PGP) effect of rhizobacterial consortia from undisturbed Chilean arid ecosystems (Consortium C1) and agro-ecosystems (Consortium C2) on plant biomass production. The PGP effects of C1 and C2 were assayed in wheat seedlings (Triticum aestivum L.) grown in pots under growth chamber conditions and in pots placed in an open greenhouse under natural conditions, using two different Chilean Andisols (Piedras Negras and Freire series) kept either at 30 or 60% of their maximum water holding capacity (MWHC). PGP effects depended on the soil type, MWHC and the growth conditions tested. Although both consortia showed PGB effects in artificial soils relative to controls in growth chambers, only C1 provoked a PGP effect at 60% MWHC in phosphorus-poor soil of the 'Piedras Negras' series. At natural conditions, however, only C1 exhibited statistically significant PGP effects at 30% MWHC in 'Piedras Negras', yet and most importantly allowed to maintain similar plant biomass as at 60% MWHC. Our results support possible applications of rhizobacterial consortia from arid ecosystems to improve wheat growth in Chilean Andisols under water shortage conditions.

  19. Deposition of SOCs in forests

    SciTech Connect

    Horstmann, M.; McLachlan, M.S.

    1995-12-31

    The bulk deposition, wet-only deposition, dry-only deposition and ambient air concentrations of PCDD/Fs, PCBs and PAHs were measured in an 80 year old spruce forest, an 80 year old mixed deciduous (beech and oak) forest, and in an adjacent clearing over a period of 1--2 years. The deposition of the less volatile compounds that are primarily particle bound in the atmosphere was similar at both sites. These compounds were deposited primarily through wet deposition, as shown by the measurements in the clearing. In contrast, the deposition of the more volatile compounds was much higher at the forest sites than in the clearing. For instance, the annual deposition of Cl{sub 4}DF was 5 times higher in the spruce forest and 8 times higher in the deciduous forest. The excess deposition in the deciduous forest was almost completely due to the leaf fall in October--December, while about half of the excess deposition in the spruce forest was the result of needle fall. A further, as yet unexplained deposition mechanism accounted for the remainder of the flux in the spruce forest. Other studies have shown that more volatile SOCs are deposited to vegetation primarily through dry gaseous deposition. Hence, while forests have little influence on the deposition of less volatile compounds like the higher chlorinated PCDD/Fs and the 5--6 ring PAHs, dry deposition to leaves/needles and their subsequent falling to the forest floor make forest soils an extremely important sink for more volatile SOC.

  20. Methane Emissions from Upland Forests

    NASA Astrophysics Data System (ADS)

    Megonigal, Patrick; Pitz, Scott; Wang, Zhi-Ping

    2016-04-01

    Global budgets ascribe 4-10% of atmospheric methane sinks to upland soils and assume that soils are the sole surface for methane exchange between upland forests and the atmosphere. The dogma that upland forests are uniformly atmospheric methane sinks was challenged a decade ago by the discovery of abiotic methane production from plant tissue. Subsequently a variety of relatively cryptic microbial and non-microbial methane sources have been proposed that have the potential to emit methane in upland forests. Despite the accumulating evidence of potential methane sources, there are few data demonstrating actual emissions of methane from a plant surface in an upland forest. We report direct observations of methane emissions from upland tree stems in two temperate forests. Stem methane emissions were observed from several tree species that dominate a forest located on the mid-Atlantic coast of North America (Maryland, USA). Stem emissions occurred throughout the growing season while soils adjacent to the trees simultaneously consumed methane. Scaling fluxes by stem surface area suggested the forest was a net methane source during a wet period in June, and that stem emissions offset 5% of the soil methane sink on an annual basis. High frequency measurements revealed diurnal cycles in stem methane emission rates, pointing to soils as the methane source and transpiration as the most likely pathway for gas transport. Similar observations were made in an upland forest in Beijing, China. However, in this case the evidence suggested the methane was not produced in soils, but in the heartwood by microbial or non-microbial processes. These data challenge the concept that forests are uniform sinks of methane, and suggest that upland forests are smaller methane sinks than previously estimated due to stem emissions. Tree emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration.

  1. Global-scale patterns of forest fragmentation

    USGS Publications Warehouse

    Riitters, K.; Wickham, J.; O'Neill, R.; Jones, B.; Smith, E.

    2000-01-01

    We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 ?? 9 pixels, "small" scale) to 59,049 km 2 (243 ?? 243 pixels, "large" scale) were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe - Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types) and Europe - Asia (four types), in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland). The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf. Copyright ?? 2000 by The Resilience Alliance.

  2. GOAT ROCKS WILDERNESS AND ADJACENT ROADLESS AREAS, WASHINGTON.

    USGS Publications Warehouse

    Church, S.E.; Close, T.J.

    1984-01-01

    The Goat Rocks Wilderness and adjacent roadless areas are a rugged, highly forested, scenic area located on the crest of the Cascade Range in south-central Washington. Several mineral claims have been staked in the area. Mineral surveys were conducted. Geochemical, geophysical, and geologic investigations indicate that three areas have probable mineral-resource potential for base metals in porphyry-type deposits. Available data are not adequate to permit definition of the potential for oil and gas. There is little likelihood for the occurrence of other kinds of energy resources in the area. Evaluation of resource potential in the three areas identified as having probable mineral-resource potential could be improved by more detailed geochemical studies and geologic mapping.

  3. Forest Resources

    SciTech Connect

    2016-06-01

    Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

  4. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  5. Imaging Vis-NIR spectroscopy - mapping SOM quality and quantity in undisturbed soil profiles of semiarid steppe in Inner Mongolia

    NASA Astrophysics Data System (ADS)

    Zeh, Lilli; Buddenbaum, Henning; Steffens, Markus

    2014-05-01

    Though soil organic matter (SOM) constitutes a small fraction of most topsoils, it plays a decisive role to many soil functions such as nutrient sorption, aggregate stability and water holding capacity. Unfortunately this important factor for soil quality is difficult to investigate due to both the elaborate techniques required and organic matters high variability over small scales. In this study VIS-NIR laboratory imaging spectroscopy is used to measure quality and quantity of SOM with a high spatial resolution in undisturbed soil profiles. Special attention is paid to changes in the amount of particulate organic matter (POM) and its chemical composition. It is known that grazing has an undisputable negative effect on soil organic carbon stocks. Therefore management of a spacious ecosystem such as semiarid steppes is supposed to be an important factor for carbon sequestration. We sampled two different sites from the semiarid steppe ecosystem in Inner Mongolia, China. One continuously grazed and the other ungrazed since 1979, both were classified as Calcic Chernozems. We expect longterm grazing to decrease carbon contents and most pronounced POM fractions as sensitive indicators. A stainless steel box (100×100×300 mm3) was used to sample undisturbed soil profiles. Until further investigations the soil boxes were dried at 30C. A hyperspectral camera recorded their visible and near infrared reflectance (400 to 1000 nm in 160 bands) with a spatial resolution of 63×63 µm2 per pixel. This procedure was repeated over three vertical cuts at a lateral distance of 25 mm through the soil boxes. After each image recording the profile was divided into ten equal squares (each 50×50 mm2). Mixed samples were extracted from each square to a depth of 5 mm. Density fractionation was used to separate fractions of POM with different degrees of decomposition. POM quality and quantity was correlated to the most relevant spectral regions. Instead of elaborated laboratory techniques

  6. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  7. Living near the edge: Being close to mature forest increases the rate of succession in beetle communities.

    PubMed

    Fountain-Jones, Nicholas M; Jordan, Gregory J; Baker, Thomas P; Balmer, Jayne M; Wardlaw, Tim; Baker, Susan C

    2015-04-01

    In increasingly fragmented landscapes, it is important to understand how mature forest affects adjacent secondary forest (forest influence). Forest influence on ecological succession of beetle communities is largely unknown. We investigated succession and forest influence using 235 m long transects across boundaries between mature and secondary forest at 15 sites, sampling a chronosequence of three forest age classes (5-10, 23- 29, and 42-46 years since clear-cutting) in tall eucalypt forest in Tasmania, Australia. Our results showed that ground-dwelling beetle communities showed strong successional changes, and in the oldest secondary forests, species considered indicators of mature forest had recolonized to abundance levels similar to those observed within adjacent mature forest stands. However, species composition also showed forest influence gradients in all age classes. Forest influence was estimated to extend 13 m and 20 m in the youngest and intermediate-aged secondary forests, respectively. However, the estimated effect extended to at least 176 m in the oldest secondary forest. Our environmental modeling suggests that leaf litter, microclimate, and soil variables were all important in explaining the spatial variation in beetle assemblages, and the relative importance of factors varied between secondary forest age classes. Mature-forest beetle communities can recolonize successfully from the edge, and our results provide a basis for land managers to build mature habitat connectivity into forest mosaics typical of production forests. Our results also indicate the importance of forest influence in determining potential conservation value of older secondary forest for beetles.

  8. Dissolved rainfall inputs and streamwater outputs in an undisturbed watershed on highly weathered soils in the Brazilian cerrado

    NASA Astrophysics Data System (ADS)

    Markewitz, Daniel; Resende, Julio C. F.; Parron, Lucilia; Bustamante, Mercedes; Klink, Carlos A.; Figueiredo, Ricardo De O.; Davidson, Eric A.

    2006-08-01

    The cerrados of Brazil cover 2 million km2. Despite the extent of these seasonally dry ecosystems, little watershed research has been focused in this region, particularly relative to the watersheds of the Amazon Basin. The cerrado shares pedogenic characteristics with the Amazon Basin in draining portions of the Brazilian shield and in possessing Oxisols over much of the landscape. The objective of this research was to quantify the stream water geochemical relationships of an undisturbed 1200 ha cerrado watershed for comparison to river geochemistry in the Amazon. Furthermore, this undisturbed watershed was used to evaluate stream discharge versus dissolved ion concentration relationships. This research was conducted in the Córrego Roncador watershed of the Reserva Ecológica do Roncador (RECOR) of the Instituto Brasileiro Geografia e Estatística (IBGE) near Brasilia, Brazil. Bulk precipitation and stream water chemistry were analysed between May 1998 and May 2000. The upland soils of this watershed are nutrient poor possessing total stocks of exchangeable elements in the upper 1 m of 81 +/- 13, 77 +/- 4, 25 +/- 3, and 1 +/- 1 kg ha-1 of K, Ca, Mg, and P, respectively. Bulk precipitation inputs of dissolved nutrients for this watershed are low and consistent with previous estimates. The nutrient-poor soils of this watershed, however, increase the relative importance of precipitation for nutrient replenishment to vegetation during episodes of ecosystem disturbance. Stream water dissolved loads were extremely dilute with conductivities ranging from 4 to 10 μS cm-1 during periods of high- and low-flow, respectively. Despite the low concentrations in this stream, geochemical relationships were similar to other Amazonian streams draining shield geologies. Discharge-concentration relationships for Ca and Mg in these highly weathered soils developed from igneous rocks of the Brazilian shield demonstrated a significant negative relationship indicating a continued

  9. Summary geochemical maps, Hoover Wilderness and adjacent study area, Mono and Tuolumne counties, California

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.; Sutley, S.J.

    1984-01-01

    The Hoover Wilderness and the adjacent Hoover Extension (East), Hoover Extension (West), and Cherry Creek A Roadless Areas (the adjacent study area) encompass approximately 153,900 acres (241 mi2; 623 km2) in the Inyo, Stanislaus, and Toiyabe Naitonal Forests, Mono and Tuolumne Counties, Calif. These two areas lie along and mostly east of the crest of the Sierra Nevada, along the north and east sides of Yosemite National Park. Elevations vary from a high of 12,446 ft (3,793 m) on the crest of the Sierra Nevada to a low of about 6,500 ft (1,981 m) near the Bridgeport Ranger Station. Access to the Hoover Wilderness and adjacent study area is by U.S. Highway 395, California State Highways 108 (Sonora Pass) and 120 (Tioga Pass), and by other paved and graded roads that lead off of these U.S. and State highways.

  10. Matrix intensification alters avian functional group composition in adjacent rainforest fragments.

    PubMed

    Deikumah, Justus P; McAlpine, Clive A; Maron, Martine

    2013-01-01

    Conversion of farmland land-use matrices to surface mining is an increasing threat to the habitat quality of forest remnants and their constituent biota, with consequences for ecosystem functionality. We evaluated the effects of matrix type on bird community composition and the abundance and evenness within avian functional groups in south-west Ghana. We hypothesized that surface mining near remnants may result in a shift in functional composition of avifaunal communities, potentially disrupting ecological processes within tropical forest ecosystems. Matrix intensification and proximity to the remnant edge strongly influenced the abundance of members of several functional guilds. Obligate frugivores, strict terrestrial insectivores, lower and upper strata birds, and insect gleaners were most negatively affected by adjacent mining matrices, suggesting certain ecosystem processes such as seed dispersal may be disrupted by landscape change in this region. Evenness of these functional guilds was also lower in remnants adjacent to surface mining, regardless of the distance from remnant edge, with the exception of strict terrestrial insectivores. These shifts suggest matrix intensification can influence avian functional group composition and related ecosystem-level processes in adjacent forest remnants. The management of matrix habitat quality near and within mine concessions is important for improving efforts to preserveavian biodiversity in landscapes undergoing intensification such as through increased surface mining.

  11. Nitrogen retention in contrasting temperate forests exposed to high nitrogen deposition

    NASA Astrophysics Data System (ADS)

    Staelens, J.; Adriaenssens, S.; Wuyts, K.; Verheyen, K.; Boeckx, P. F.

    2011-12-01

    A better understanding of factors affecting nitrogen (N) retention is needed to assess the impact of changing anthropogenic N emissions and climatic conditions on N cycling and N loss by terrestrial ecosystems. Retention of N has been demonstrated for a wide range of forests, including ecosystems exposed to chronically enhanced N deposition, but it is still unclear which factors determine this N retention capacity. Therefore, we examined the possible effects of forest type on N retention using stable N isotopes. The study was carried out in adjacent equal-aged deciduous (pedunculate oak (Quercus robur L.)) and coniferous (Scots pine (Pinus sylvestris L.)) stands with a similar stand history and growing on a well-drained sandy soil in a region with enhanced N deposition (Belgium). The N input-output budgets and gross soil N transformation rates differed significantly between the two stands. The forest floor was exposed to a high inorganic N input from atmospheric deposition, which was nearly twice as high in the pine stand (33 ± 2 kg N ha-1 yr-1; mean ± standard error) as in the oak stand (18 ± 1 kg N ha-1 yr-1). The N input was reflected in the soil solution under the rooting zone, but the mean nitrate concentration was eight times higher under pine (19 ± 5 mg N L-1) than under oak (2.3 ± 0.9 mg N L-1). Gross N dynamics in the mineral topsoil were determined by in situ 15N labelling of undisturbed soil cores combined with numerical data analysis. Gross N mineralization was two times faster in the oak soil while nitrate production was two times faster in the pine soil, indicating a dominant effect of vegetation cover on soil N cycling. The higher gross nitrification, particularly due to oxidation of organic N, in the pine soil compared to the oak soil, combined with negligible nitrate immobilization, was in line with the higher nitrate leaching under the pine forest. On a larger spatial and temporal scale, the fate of dissolved inorganic N within these forests

  12. A large-scale field assessment of carbon stocks in human-modified tropical forests.

    PubMed

    Berenguer, Erika; Ferreira, Joice; Gardner, Toby Alan; Aragão, Luiz Eduardo Oliveira Cruz; De Camargo, Plínio Barbosa; Cerri, Carlos Eduardo; Durigan, Mariana; Cosme De Oliveira Junior, Raimundo; Vieira, Ima Célia Guimarães; Barlow, Jos

    2014-12-01

    Tropical rainforests store enormous amounts of carbon, the protection of which represents a vital component of efforts to mitigate global climate change. Currently, tropical forest conservation, science, policies, and climate mitigation actions focus predominantly on reducing carbon emissions from deforestation alone. However, every year vast areas of the humid tropics are disturbed by selective logging, understory fires, and habitat fragmentation. There is an urgent need to understand the effect of such disturbances on carbon stocks, and how stocks in disturbed forests compare to those found in undisturbed primary forests as well as in regenerating secondary forests. Here, we present the results of the largest field study to date on the impacts of human disturbances on above and belowground carbon stocks in tropical forests. Live vegetation, the largest carbon pool, was extremely sensitive to disturbance: forests that experienced both selective logging and understory fires stored, on average, 40% less aboveground carbon than undisturbed forests and were structurally similar to secondary forests. Edge effects also played an important role in explaining variability in aboveground carbon stocks of disturbed forests. Results indicate a potential rapid recovery of the dead wood and litter carbon pools, while soil stocks (0-30 cm) appeared to be resistant to the effects of logging and fire. Carbon loss and subsequent emissions due to human disturbances remain largely unaccounted for in greenhouse gas inventories, but by comparing our estimates of depleted carbon stocks in disturbed forests with Brazilian government assessments of the total forest area annually disturbed in the Amazon, we show that these emissions could represent up to 40% of the carbon loss from deforestation in the region. We conclude that conservation programs aiming to ensure the long-term permanence of forest carbon stocks, such as REDD+, will remain limited in their success unless they effectively

  13. Interactive effects between N addition and disturbance on boreal forest ecosystem structure and function

    NASA Astrophysics Data System (ADS)

    Nordin, Annika; Strengbom, Joachim; From, Fredrik

    2014-05-01

    In management of boreal forests, nitrogen (N) enrichment from atmospheric deposition or from forest fertilization can appear in combination with land-use related disturbances, i.e. tree harvesting by clear-felling. Long-term interactive effects between N enrichment and disturbance on boreal forest ecosystem structure and function are, however, poorly known. We investigated effects of N enrichment by forest fertilization done > 25 years ago on forest understory species composition in old-growth (undisturbed) forests, and in forests clear-felled 10 years ago (disturbed). In clear-felled forests we also investigated effects of the previous N addition on growth of tree saplings. The results show that the N enrichment effect on the understory species composition was strongly dependent on the disturbance caused by clear-felling. In undisturbed forests, there were small or no effects on understory species composition from N addition. In contrast, effects were large in forests first exposed to N addition and subsequently disturbed by clear-felling. Effects of N addition differed among functional groups of plants. Abundance of graminoids increased (+232%) and abundance of dwarf shrubs decreased (-44%) following disturbance in N fertilized forests. For vascular plants, the two perturbations had contrasting effects on α-(within forests) and β-diversity (among forests): in disturbed forests, N addition reduced, or had no effect on α-diversity, while β-diversity increased. For bryophytes, negative effects of disturbance on α-diversity were smaller in N fertilized forests than in forests not fertilized, while neither N addition nor disturbance had any effects on β-diversity. Moreover, sapling growth in forests clear-felled 10 years ago was significantly higher in previously N fertilized forests than in forests not fertilized. Our study show that effects of N addition on plant communities may appear small, short-lived, or even absent until exposed to a disturbance. This

  14. Protecting rain forests and forager's rights using LANDSAT imagery

    NASA Technical Reports Server (NTRS)

    Wilkie, David S.

    1991-01-01

    Creating rain forest reserves is vital given the global decline in biodiversity. Yet, the plants and animals that will be protected from untrammeled commercial exploitation within such reserves constitute essential resources for indigenous foragers and farmers. Balancing the needs of local subsistence level populations with the goals of national and international conservation agencies requires a thorough understanding of the mutual impacts that arise from the interaction of park and people. In the Ituri forest of Zaire, LANDSAT TM image analysis and GPS ground truth data were used to locate human settlements so that boundaries of the proposed Okapi Reserve could be chosen to minimize its impact on the subsistence practices of the local foragers and farmers. Using satellite imagery in conjunction with cultural information should help to ensure traditional resource exploitation rights of indigenous peoples whilst simultaneously protecting the largest contiguous area of undisturbed forest.

  15. Flexibility in nest-site choice and nesting success of Turdus rufiventris (Turdidae) in a montane forest in northwestern argentina

    USGS Publications Warehouse

    Lomascolo, S.B.; Monmany, A.C.; Malizia, A.; Martin, T.E.

    2010-01-01

    We studied the consequences of nest-site choice on nesting success under differing disturbance levels for the Rufous-bellied Thrush (Turdus rufiventris). We compared nest-site choice and nest success between a disturbed site and an undisturbed site in a montane subtropical forest in northwestern Argentina. We found no overall difference in daily predation rate (DPR) between the disturbed and undisturbed sites. However, DPR of nests on bromeliads was significantly lower at the microhabitat level than on other types of subtrates at the disturbed site. T. rufiventris used bromeliads for nesting more often than expected by chance at the disturbed site. DPR did not differ between substrates at the undisturbed site and T. rufiventris used all substrates according to their availability. Nests had higher predation at the disturbed site when DPR on non-bromeliad substrates was compared between disturbed and undisturbed sites. Nest fate was independent of nest height. Our results suggest T. rufiventris' flexibility in nest-site choice, as reflected by increased use of the safest sites, i.e., bromeliads, in the disturbed site compared to the undisturbed site, may allow this species to survive in an otherwise much riskier habitat. Our results illustrate how microhabitat-scale effects can mediate landscape scale effects. ?? 2010 by the Wilson Ornithological Society.

  16. The importance of the riparian zone and in-stream processes in nitrate attenuation in undisturbed and agricultural watersheds – a review of the scientific literature

    USGS Publications Warehouse

    Ranalli, Anthony J.; Macalady, Donald L.

    2010-01-01

    We reviewed published studies from primarily glaciated regions in the United States, Canada, and Europe of the (1) transport of nitrate from terrestrial ecosystems to aquatic ecosystems, (2) attenuation of nitrate in the riparian zone of undisturbed and agricultural watersheds, (3) processes contributing to nitrate attenuation in riparian zones, (4) variation in the attenuation of nitrate in the riparian zone, and (5) importance of in-stream and hyporheic processes for nitrate attenuation in the stream channel. Our objectives were to synthesize the results of these studies and suggest methodologies to (1) monitor regional trends in nitrate concentration in undisturbed 1st order watersheds and (2) reduce nitrate loads in streams draining agricultural watersheds. Our review reveals that undisturbed headwater watersheds have been shown to be very retentive of nitrogen, but the importance of biogeochemical and hydrological riparian zone processes in retaining nitrogen in these watersheds has not been demonstrated as it has for agricultural watersheds. An understanding of the role of the riparian zone in nitrate attenuation in undisturbed watersheds is crucial because these watersheds are increasingly subject to stressors, such as changes in land use and climate, wildfire, and increases in atmospheric nitrogen deposition. In general, understanding processes controlling the concentration and flux of nitrate is critical to identifying and mapping the vulnerability of watersheds to water quality changes due to a variety of stressors. In undisturbed and agricultural watersheds we propose that understanding the importance of riparian zone processes in 2nd order and larger watersheds is critical. Research is needed that addresses the relative importance of how the following sources of nitrate along any given stream reach might change as watersheds increase in size and with flow: (1) inputs upstream from the reach, (2) tributary inflow, (3) water derived from the riparian zone

  17. The importance of the riparian zone and in-stream processes in nitrate attenuation in undisturbed and agricultural watersheds - A review of the scientific literature

    NASA Astrophysics Data System (ADS)

    Ranalli, Anthony J.; Macalady, Donald L.

    2010-08-01

    SummaryWe reviewed published studies from primarily glaciated regions in the United States, Canada, and Europe of the (1) transport of nitrate from terrestrial ecosystems to aquatic ecosystems, (2) attenuation of nitrate in the riparian zone of undisturbed and agricultural watersheds, (3) processes contributing to nitrate attenuation in riparian zones, (4) variation in the attenuation of nitrate in the riparian zone, and (5) importance of in-stream and hyporheic processes for nitrate attenuation in the stream channel. Our objectives were to synthesize the results of these studies and suggest methodologies to (1) monitor regional trends in nitrate concentration in undisturbed 1st order watersheds and (2) reduce nitrate loads in streams draining agricultural watersheds. Our review reveals that undisturbed headwater watersheds have been shown to be very retentive of nitrogen, but the importance of biogeochemical and hydrological riparian zone processes in retaining nitrogen in these watersheds has not been demonstrated as it has for agricultural watersheds. An understanding of the role of the riparian zone in nitrate attenuation in undisturbed watersheds is crucial because these watersheds are increasingly subject to stressors, such as changes in land use and climate, wildfire, and increases in atmospheric nitrogen deposition. In general, understanding processes controlling the concentration and flux of nitrate is critical to identifying and mapping the vulnerability of watersheds to water quality changes due to a variety of stressors. In undisturbed and agricultural watersheds we propose that understanding the importance of riparian zone processes in 2nd order and larger watersheds is critical. Research is needed that addresses the relative importance of how the following sources of nitrate along any given stream reach might change as watersheds increase in size and with flow: (1) inputs upstream from the reach, (2) tributary inflow, (3) water derived from the

  18. Adjacent Segment Pathology after Anterior Cervical Fusion

    PubMed Central

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon

    2016-01-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion. PMID:27340541

  19. Radon volumetric activity and ion production in the undisturbed lower atmosphere: Ground-based observations and numerical modeling

    NASA Astrophysics Data System (ADS)

    Anisimov, S. V.; Galichenko, S. V.; Aphinogenov, K. V.; Makrushin, A. P.; Shikhova, N. M.

    2017-01-01

    The results of in situ ground-based observations of radon volumetric activity carried out at the Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (58°04' N; 38°14' E) are presented. Modeling the characteristic diurnal variation in the ion production rate in the undisturbed midlatitude lower atmosphere above land is carried out. The Lagrangian stochastic model of turbulent transport is developed in application to determining the vertical profiles of radon activity for 222Rn and 220Rn isotopes and their radioactive decay products. The results calculated by the Lagrangian stochastic model are matched with the analytical solution for the free atmosphere. Based on the model, the estimate is obtained for the rate of radon outflow from the convective boundary layer to the free clear sky atmosphere. The implications of temperature stratification of the atmosphere for the vertical distribution of the ion production rate at the different radon emission rate are explored.

  20. Apparatus for Collection of Fecal Samples from Undisturbed Spiny Mice (Acomys cahirinus) Living in a Complex Social Group

    PubMed Central

    Frynta, Daniel; Nováková, Marcela; Kutalová, Hana; Palme, Rupert; Sedláček, František

    2009-01-01

    Assessment of fecal glucocorticoid metabolites has become a widely used method for monitoring stress responses. Because most small rodents are social animals whose physiologic parameters are affected by social stimuli, individual housing may compromise these data. Nevertheless, housing rodents in families or social groups may be an important limitation to the experimental design. The challenge is to collect samples from individual rodents while avoiding stress-associated effects from the sampling method itself. Here we present an apparatus and protocol allowing routine repeated collection of an individual rodent's fresh fecal samples without noticeable disturbance of any of the study animals; continuous maintenance of studied animals in a familiar environment; group housing; and uninterrupted visual and olfactory communication among group members during sampling. The apparatus consists of 1 central and 4 lateral compartments. The experimental animal was allowed to enter a lateral compartment voluntarily, where it remained for the short (4 h) period necessary for sample collection before rejoining the rest of the group. Evaluations involved Egyptian spiny mice, a social rodent increasingly studied in laboratories. The results confirmed the repeatability of the assessment of baseline levels of glucocorticoid metabolites. Moreover, keeping the animals in our experimental apparatus did not induce any increase in the levels of glucocorticoid metabolites, even when isolation in the compartment was relatively prolonged. We interpret these results as confirmation that our sampling procedure allows repeated individual sampling within a nearly undisturbed social unit. PMID:19383218

  1. Apparatus for collection of fecal samples from undisturbed spiny mice (Acomys cahirinus) living in a complex social group.

    PubMed

    Frynta, Daniel; Nováková, Marcela; Kutalová, Hana; Palme, Rupert; Sedlácek, Frantisek

    2009-03-01

    Assessment of fecal glucocorticoid metabolites has become a widely used method for monitoring stress responses. Because most small rodents are social animals whose physiologic parameters are affected by social stimuli, individual housing may compromise these data. Nevertheless, housing rodents in families or social groups may be an important limitation to the experimental design. The challenge is to collect samples from individual rodents while avoiding stress-associated effects from the sampling method itself. Here we present an apparatus and protocol allowing routine repeated collection of an individual rodent's fresh fecal samples without noticeable disturbance of any of the study animals; continuous maintenance of studied animals in a familiar environment; group housing; and uninterrupted visual and olfactory communication among group members during sampling. The apparatus consists of 1 central and 4 lateral compartments. The experimental animal was allowed to enter a lateral compartment voluntarily, where it remained for the short (4 h) period necessary for sample collection before rejoining the rest of the group. Evaluations involved Egyptian spiny mice, a social rodent increasingly studied in laboratories. The results confirmed the repeatability of the assessment of baseline levels of glucocorticoid metabolites. Moreover, keeping the animals in our experimental apparatus did not induce any increase in the levels of glucocorticoid metabolites, even when isolation in the compartment was relatively prolonged. We interpret these results as confirmation that our sampling procedure allows repeated individual sampling within a nearly undisturbed social unit.

  2. Grazing effects on aboveground primary production and root biomass of early-seral, mid-seral, and undisturbed semiarid grassland

    USGS Publications Warehouse

    Milchunas, D.G.; Vandever, M.W.

    2013-01-01

    Annual/perennial and tall/short plant species differentially dominate early to late successional shortgrass steppe communities. Plant species can have different ratios of above-/below-ground biomass distributions and this can be modified by precipitation and grazing. We compared grazing effects on aboveground production and root biomass in early- and mid-seral fields and undisturbed shortgrass steppe. Production averaged across four years and grazed and ungrazed treatments were 246, 134, and 102 g m−2 yr−1 for the early-, mid-seral, and native sites, respectively, while root biomass averaged 358, 560, and 981 g m−2, respectively. Early- and mid-seral communities provided complimentary forage supplies but at the cost of root biomass. Grazing increased, decreased, or had no effect on aboveground production in early-, mid-seral, and native communities, and had no effect on roots in any. Grazing had some negative effects on early spring forage species, but not in the annual dominated early-seral community. Dominant species increased with grazing in native communities with a long evolutionary history of grazing by large herbivores, but had no effects on the same species in mid-seral communities. Effects of grazing in native communities in a region cannot necessarily be used to predict effects at other seral stages.

  3. Evaluation of nitrification inhibitor 3,4-dimethyl pyrazole phosphate on nitrogen leaching in undisturbed soil columns.

    PubMed

    Yu, Qiaogang; Chen, Yingxu; Ye, Xuezhu; Zhang, Qiuling; Zhang, Zhijian; Tian, Ping

    2007-03-01

    The application of nitrogen fertilizers leads to various ecological problems such as nitrate leaching. The use of nitrification inhibitors (NI) as nitrate leaching retardants is a proposal that has been suggested for inclusion in regulations in many countries. In this study, the efficacy of the new NI, 3,4-dimethyl pyrazole phosphate (DMPP), was tested under simulated high-risk leaching situations in two types of undisturbed soil columns. The results showed that the accumulative leaching losses of soil nitrate under treatment of urea with 1.0% DMPP, from columns of silt loam soil and heavy clay soil, were 66.8% and 69.5% lower than those soil columns tested with regular urea application within the 60 days observation, respectively. However, the losses of ammonium leaching were reversely increased 9.7% and 6.7% under the former treatment than the latter one. Application of regular urea with 1.0% DMPP addition can reduce about 59.3%-63.1% of total losses of inorganic nitrogen via leaching. The application of DMPP to urea had stimulated the inhibition effects of DMPP on the ammonium nitrification process in the soil up to 60 days. It is proposed that the DMPP could be used as an effective NI to control inorganic N leaching losses, minimizing the risk of nitrate pollution in shallow groundwater.

  4. Distribution of carabid beetles (Coleoptera: Carabidae) across a forest-grassland ecotone in southwestern China.

    PubMed

    Yu, Xiao-Dong; Luo, Tian-Hong; Zhou, Hong-Zhang; Yang, Jian

    2007-04-01

    This paper studied the occurrence of carabid beetles (Coleoptera: Carabidae) in the forest edge, the adjacent forest interior, and the surrounding grassland in southwestern China. Beetles were collected with pitfall traps along five replicated transects. Forest species rarely penetrated into the grassland from the forest interior, and the grassland specialists were not found in the forest interior. The forest edge hosted additional species from the adjacent grassland that increased its overall species richness. Nearly all forest species (23 of 24 species) and grassland species (13 of 15 species) can be found in the forest edge. Carabids of the forest edge were more similar to those of the forest interior than to those of the grassland by ordination and cluster analysis. Based on the specificity and fidelity, carabids can be distinguished into five species groups: habitat generalists, grassland-associated species, forest generalists, forest specialists, and edge-associated species. Multiple linear regression analysis showed that canopy cover and/or shrub cover were the most important factors in determining the richness, abundance, and diversity of carabids. The forest edge may serve as a transition zone for dispersal and re-colonization of carabid beetles from adjacent habitats and therefore is important for natural conservation.

  5. Changes to the N cycle following bark beetle outbreaks in two contrasting conifer forest types.

    PubMed

    Griffin, Jacob M; Turner, Monica G

    2012-10-01

    Outbreaks of Dendroctonus beetles are causing extensive mortality in conifer forests throughout North America. However, nitrogen (N) cycling impacts among forest types are not well known. We quantified beetle-induced changes in forest structure, soil temperature, and N cycling in Douglas-fir (Pseudotsuga menziesii) forests of Greater Yellowstone (WY, USA), and compared them to published lodgepole pine (Pinus contorta var. latifolia) data. Five undisturbed stands were compared to five beetle-killed stands (4-5 years post-outbreak). We hypothesized greater N cycling responses in Douglas-fir due to higher overall N stocks. Undisturbed Douglas-fir stands had greater litter N pools, soil N, and net N mineralization than lodgepole pine. Several responses to disturbance were similar between forest types, including a pulse of N-enriched litter, doubling of soil N availability, 30-50 % increase in understory cover, and 20 % increase in foliar N concentration of unattacked trees. However, the response of some ecosystem properties notably varied by host forest type. Soil temperature was unaffected in Douglas-fir, but lowered in lodgepole pine. Fresh foliar %N was uncorrelated with net N mineralization in Douglas-fir, but positively correlated in lodgepole pine. Though soil ammonium and nitrate, net N mineralization, and net nitrification all doubled, they remained low in both forest types (<6 μg N g soil(-1) NH(4) (+)or NO(3) (-); <25 μg N g soil(-1) year(-1) net N mineralization; <8 μg N g soil(-1) year(-1) net nitrification). Results suggest that beetle disturbance affected litter and soil N cycling similarly in each forest type, despite substantial differences in pre-disturbance biogeochemistry. In contrast, soil temperature and soil N-foliar N linkages differed between host forest types. This result suggests that disturbance type may be a better predictor of litter and soil N responses than forest type due to similar disturbance mechanisms and disturbance legacies

  6. 'Laguna Hollow'Undisturbed

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image shows the patch of soil at the bottom of the shallow depression dubbed 'Laguna Hollow' where the Mars Exploration Rover Spirit will soon begin trenching. Scientists are intrigued by the clustering of small pebbles and the crack-like fine lines, which indicate a coherent surface that expands and contracts. A number of processes can cause materials to expand and contract, including cycles of heating and cooling; freezing and thawing; and rising and falling of salty liquids within a substance. This false-color image was created using the blue, green and infrared filters of the rover's panoramic camera. Scientists chose this particular combination of filters to enhance the heterogeneity of the martian soil.

  7. Adjacent-level arthroplasty following cervical fusion.

    PubMed

    Rajakumar, Deshpande V; Hari, Akshay; Krishna, Murali; Konar, Subhas; Sharma, Ankit

    2017-02-01

    OBJECTIVE Adjacent-level disc degeneration following cervical fusion has been well reported. This condition poses a major treatment dilemma when it becomes symptomatic. The potential application of cervical arthroplasty to preserve motion in the affected segment is not well documented, with few studies in the literature. The authors present their initial experience of analyzing clinical and radiological results in such patients who were treated with arthroplasty for new or persistent arm and/or neck symptoms related to neural compression due to adjacent-segment disease after anterior cervical discectomy and fusion (ACDF). METHODS During a 5-year period, 11 patients who had undergone ACDF anterior cervical discectomy and fusion (ACDF) and subsequently developed recurrent neck or arm pain related to adjacent-level cervical disc disease were treated with cervical arthroplasty at the authors' institution. A total of 15 devices were implanted (range of treated levels per patient: 1-3). Clinical evaluation was performed both before and after surgery, using a visual analog scale (VAS) for pain and the Neck Disability Index (NDI). Radiological outcomes were analyzed using pre- and postoperative flexion/extension lateral radiographs measuring Cobb angle (overall C2-7 sagittal alignment), functional spinal unit (FSU) angle, and range of motion (ROM). RESULTS There were no major perioperative complications or device-related failures. Statistically significant results, obtained in all cases, were reflected by an improvement in VAS scores for neck/arm pain and NDI scores for neck pain. Radiologically, statistically significant increases in the overall lordosis (as measured by Cobb angle) and ROM at the treated disc level were observed. Three patients were lost to follow-up within the first year after arthroplasty. In the remaining 8 cases, the duration of follow-up ranged from 1 to 3 years. None of these 8 patients required surgery for the same vertebral level during the follow

  8. Transport of bromide and pesticides through an undisturbed soil column: a modeling study with global optimization analysis.

    PubMed

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2015-01-01

    The fate of pesticides in tropical soils is still not understood as well as it is for soils in temperate regions. In this study, water flow and transport of bromide tracer and five pesticides (atrazine, imazaquin, sulfometuron methyl, S-metolachlor, and imidacloprid) through an undisturbed soil column of tropical Oxisol were analyzed using a one-dimensional numerical model. The numerical model is based on Richards' equation for solving water flow, and the advection-dispersion equation for solving solute transport. Data from a laboratory column leaching experiment were used in the uncertainty analysis using a global optimization methodology to evaluate the model's sensitivity to transport parameters. All pesticides were found to be relatively mobile (sorption distribution coefficients lower than 2 cm(3) g(-1)). Experimental data indicated significant non-conservative behavior of bromide tracer. All pesticides, with the exception of imidacloprid, were found less persistent (degradation half-lives smaller than 45 days). Three of the five pesticides (atrazine, sulfometuron methyl, and S-metolachlor) were better described by the linear kinetic sorption model, while the breakthrough curves of imazaquin and imidacloprid were more appropriately approximated using nonlinear instantaneous sorption. Sensitivity analysis suggested that the model is most sensitive to sorption distribution coefficient. The prediction limits contained most of the measured points of the experimental breakthrough curves, indicating adequate model concept and model structure for the description of transport processes in the soil column under study. Uncertainty analysis using a physically-based Monte Carlo modeling of pesticide fate and transport provides useful information for the evaluation of chemical leaching in Hawaii soils.

  9. Land Use Effects on Vegetation Diversity in High-Elevation Ecosystems: a Comparison of Disturbed and Undisturbed Paramos

    NASA Astrophysics Data System (ADS)

    Avery, W. A.; Riveros-Iregui, D.; Jaimes, J. C.; Washington-Allen, R. A.; Delgado, A.

    2012-12-01

    The relationship between vegetation density, diversity, and structure in a given ecosystem and the capacity for that ecosystem to provide services has been widely investigated. However, the capacity of ecological systems to adapt to various degrees of anthropogenic land use represents a significant challenge in scientific investigations. We examined the effects of disturbance on vegetation diversity and ecosystem function across two paramos in the Andes Mountains of Colombia. The paramo, an alpine meadow that occurs at elevations above 3,000 m mainly in South America, is the major drinking water provider for the Andean highlands. These meadows collect water during the rainy season and release it during the dry season. The goal of this study is to elucidate the relationship between land use, vegetation biodiversity, and ecosystem services. Plant species richness was collected in two paramo watersheds with similar elevation and climatic conditions but with different historic land use, including potato cultivation and cattle grazing. Leaf area index (LAI), canopy cover, species richness and height diversity was quantified using a plant canopy analyzer and terrestrial LiDAR across thirty-six 1-m x1-m plots in each watershed. Results show that species richness is higher in the undisturbed paramo watershed than in the disturbed site. However, species complexity and richness increase in areas closer to streams in both watersheds, suggesting that ecosystem adaptation to disturbance is dependant on landscape position. Our results highlight that paramo ecosystems are vulnerable to human-induced disturbance and their capacity to respond to such disturbance is dependent on proximity to streams.

  10. Transport of bromide and pesticides through an undisturbed soil column: A modeling study with global optimization analysis

    NASA Astrophysics Data System (ADS)

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2015-04-01

    The fate of pesticides in tropical soils is still not understood as well as it is for soils in temperate regions. In this study, water flow and transport of bromide tracer and five pesticides (atrazine, imazaquin, sulfometuron methyl, S-metolachlor, and imidacloprid) through an undisturbed soil column of tropical Oxisol were analyzed using a one-dimensional numerical model. The numerical model is based on Richards' equation for solving water flow, and the advection-dispersion equation for solving solute transport. Data from a laboratory column leaching experiment were used in the uncertainty analysis using a global optimization methodology to evaluate the model's sensitivity to transport parameters. All pesticides were found to be relatively mobile (sorption distribution coefficients lower than 2 cm3 g- 1). Experimental data indicated significant non-conservative behavior of bromide tracer. All pesticides, with the exception of imidacloprid, were found less persistent (degradation half-lives smaller than 45 days). Three of the five pesticides (atrazine, sulfometuron methyl, and S-metolachlor) were better described by the linear kinetic sorption model, while the breakthrough curves of imazaquin and imidacloprid were more appropriately approximated using nonlinear instantaneous sorption. Sensitivity analysis suggested that the model is most sensitive to sorption distribution coefficient. The prediction limits contained most of the measured points of the experimental breakthrough curves, indicating adequate model concept and model structure for the description of transport processes in the soil column under study. Uncertainty analysis using a physically-based Monte Carlo modeling of pesticide fate and transport provides useful information for the evaluation of chemical leaching in Hawaii soils.

  11. Birds of a high-altitude cloud forest in Alta Verapaz, Guatemala.

    PubMed

    Eisermann, Knut; Schulz, Ulrich

    2005-01-01

    The Northern Central American Highlands have been recognized as endemic bird area, but little is known about bird communities in Guatemalan cloud forests. From 1997 to 2001 a total of 142 bird species were recorded between 2000 and 2400 masl in cloud forest and agricultural clearings on Montaña Caquipec (Alta Verapaz, Guatemala). The bird community is described based on line transect counts within the forest. Pooling census data from undisturbed and disturbed forest, the Gray-breasted Wood-Wren (Henicorhina leucophrys) was found to be the most abundant species, followed in descending order by the Common Bush-Tanager (Chlorospingus ophthalmicus), the Paltry Tyrannulet (Zimmerius vilissimus), the Yellowish Flycatcher (Empidonax flavescens), the Ruddy-capped Nightingale-Thrush (Catharus frantzi), and the Amethyst-throated Hummingbird (Lampornis amethystinus). Bird communities in undisturbed and disturbed forest were found to be similar (Serensen similarity index 0.85), indicating low human impact. Of all recorded species, approximately 27% were Nearctic-Neotropical migratory birds. The most abundant one was the Wilson's Warbler (Wilsonia pusilla). The Montaña Caquipec is an important area for bird conservation, which is indicated by the presence of four species listed in the IUCN Red List (Highland Guan Penelopina nigra, Resplendent Quetzal Pharomachrus mocinno, Pink-headed Warbler Ergaticus versicolor, Golden-cheeked Warbler Dendroica chrysoparia), and 42 Mesoamerican endemics, of which 14 species are endemic to the Central American Highlands. The results presented here will be useful as baseline data for a long-term monitoring.

  12. Effects of disturbance and climate change on ecosystem performance in the Yukon River Basin boreal forest

    USGS Publications Warehouse

    Wylie, Bruce K.; Rigge, Matthew B.; Brisco, Brian; Mrnaghan, Kevin; Rover, Jennifer R.; Long, Jordan

    2014-01-01

    A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000–2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the EEP and GSN relationship and represent performance departures from expected performance conditions. These performance data were used to monitor successional events following fire. Results suggested that maximum EPA occurs 30–40 years following fire, and deciduous stands generally have higher EPA than coniferous stands. Mean undisturbed EEP is projected to increase 5.6% by 2040 and 8.7% by 2070, suggesting an increased deciduous component in boreal forests. Our results contribute to the understanding of boreal forest successional dynamics and its response to climate change. This information enables informed decisions to prepare for, and adapt to, climate change in the Yukon River Basin forest.

  13. 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.

  14. Adaptive responses and disruptive effects: how major wildfire influences kinship-based social interactions in a forest marsupial.

    PubMed

    Banks, Sam C; Blyton, Michaela D J; Blair, David; McBurney, Lachlan; Lindenmayer, David B

    2012-02-01

    Environmental disturbance is predicted to play a key role in the evolution of animal social behaviour. This is because disturbance affects key factors underlying social systems, such as demography, resource availability and genetic structure. However, because natural disturbances are unpredictable there is little information on their effects on social behaviour in wild populations. Here, we investigated how a major wildfire affected cooperation (sharing of hollow trees) by a hollow-dependent marsupial. We based two alternative social predictions on the impacts of fire on population density, genetic structure and resources. We predicted an adaptive social response from previous work showing that kin selection in den-sharing develops as competition for den resources increases. Thus, kin selection should occur in burnt areas because the fire caused loss of the majority of hollow-bearing trees, but no detectable mortality. Alternatively, fire may have a disruptive social effect, whereby postfire home range-shifts 'neutralize' fine-scale genetic structure, thereby removing opportunities for kin selection between neighbours. Both predictions occurred: the disruptive social effect in burnt habitat and the adaptive social response in adjacent unburnt habitat. The latter followed a massive demographic influx to unburnt 'refuge' habitat that increased competition for dens, leading to a density-related kin selection response. Our results show remarkable short-term plasticity of animal social behaviour and demonstrate how the social effects of disturbance extend into undisturbed habitat owing to landscape-scale demographic shifts. We predicted long-term changes in kinship-based cooperative behaviour resulting from the genetic and resource impacts of forecast changes to fire regimes in these forests.

  15. Tropical forests

    SciTech Connect

    Not Available

    1985-01-01

    Major international aid and nongovernmental groups have agreed on a strategy to conserve tropical forests. Their plan calls for a $5.3 billion, five-year program for the 56 most critically affected countries. This report consists of three parts. The Plan details the costs of deforestation in both developing and industrialized countries, uncovers its real causes, and outlines a five-part action plan. Case Studies reviews dozens of detailed accounts of successful forest management projects from around the world, covering wide-ranging ecological conditions and taking into account the economics of forest products in different marketing situations. Country Investment Profiles spell out country-by-country listings of what should be done, who should do it, and how much it will cost.

  16. Differential Effects of Wildfire and Forest Harvest on Snow Hydrology in the Oregon Cascades

    NASA Astrophysics Data System (ADS)

    Nolin, A. W.; Gleason, K. E.; Roth, T.; Cooper, M. G.

    2014-12-01

    Snow hydrology, climate, and forest ecosystems are intricately connected, with snow serving as a key moisture source for forests while forests fundamentally affect snow accumulation and ablation. These connections have important implications for western US water resources and forest management. Forests reduce snow accumulation via canopy interception while ablation is affected via changes in energy balance. We contrast the snow hydrology of undisturbed forests in the Oregon Cascades with those affected by wildfire and forest harvest. When the forest canopy is removed by wildfire or forest harvest it increases total snow accumulation and increases snowmelt rates. After a high-severity wildfire, canopy removal increases light transmission to the snow. The charred standing trees shed burned debris onto the snowpack surface decreasing snow albedo. The net result for the snowpack is much higher absorbed shortwave radiation and earlier/faster melt. Our work shows that the albedo effect can persist for several years after the fire. Forest harvest also reduces the forest canopy but unlike the post-wildfire environment, forest litter decreases. Our measurements and modeling results show that the effects of forest harvest on snow vary with elevation. At our lower-elevation warmer sites, snow persists longer in the open areas than in the forest while at the higher elevation colder sites, snow persists longer in the forest. In addition to our snow hydrology results, we present preliminary hydrologic modeling showing how these differences in snow accumulation and melt rates influence streamflow in watersheds dominated by surface runoff and in those dominated by groundwater flow.

  17. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  18. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  19. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2011-10-01 2011-10-01 false Signals at adjacent control points....

  20. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points....

  1. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  2. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  3. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  4. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  5. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  6. Seismicity in Azerbaijan and Adjacent Caspian Sea

    SciTech Connect

    Panahi, Behrouz M.

    2006-03-23

    So far no general view on the geodynamic evolution of the Black Sea to the Caspian Sea region is elaborated. This is associated with the geological and structural complexities of the region revealed by geophysical, geochemical, petrologic, structural, and other studies. A clash of opinions on geodynamic conditions of the Caucasus region, sometimes mutually exclusive, can be explained by a simplified interpretation of the seismic data. In this paper I analyze available data on earthquake occurrences in Azerbaijan and the adjacent Caspian Sea region. The results of the analysis of macroseismic and instrumental data, seismic regime, and earthquake reoccurrence indicate that a level of seismicity in the region is moderate, and seismic event are concentrated in the shallow part of the lithosphere. Seismicity is mostly intra-plate, and spatial distribution of earthquake epicenters does not correlate with the plate boundaries.

  7. Modeling of penconazole and metalaxyl mobility in undisturbed vineyard soil cores, unamended and amended with spent mushroom substrate

    NASA Astrophysics Data System (ADS)

    Marin-Benito, Jesus Maria; Mamy, Laure; Rodriguez-Cruz, Maria Sonia; Sanchez-Martin, Maria Jesus

    2013-04-01

    In Spain, one of the main producers of mushrooms in the world, a huge amount of the substrates used for the growth of mushrooms have to be eliminated after harvest. However, this substrate represents a promising amendment because of its high organic matter content and, in particular, it could be used in vineyard soils because they generally are poor in organic matter. But the effect of this amendment on the fate in soils of fungicides that are massively used in vineyards is unknown. Therefore, the objectives of this work were to model the mobility of two fungicides, penconazole and metalaxyl, in undisturbed vineyard soil columns using the PRZM3 (Pesticide Root Zone Model) parameterized with laboratory data, and to compare the simulations with the experimental results obtained in mobility studies. Soil cores (40 cm x 9 cm d.i.) were collected from experimental plots in three different vineyard soils of La Rioja (Spain). Three different treatments were tested in each soil: natural (control) soil, soil amended with fresh spent mushroom substrate, and soil amended with composted spent mushroom substrate. The leaching of fungicides was studied in non-incubated and incubated (outdoors for 77 days) soil cores under unsaturated flow conditions. In general, the addition of mushroom substrates decreased the leaching of fungicides compared to control soils. For the most hydrophobic fungicide, penconazole, the predictions obtained by the model were highly correlated (r > 0.88) with the experimental results. Penconazole was never observed in the leachates, its vertical distribution was similar within all soil profiles, and retention of almost all the fungicide was into the topsoil (0-8cm). For the less hydrophobic fungicide, metalaxyl, and the CGA 62826 metabolite generated from its degradation during the experimental period, PRZM3 was not able to reproduce the observations and it was necessary to calibrate the model. After calibration, the correlation between model predictions

  8. Modeling the impact of disturbances on the carbon cycle of a mixed-deciduous forest in the upper Midwest

    NASA Astrophysics Data System (ADS)

    Frasson, R.; Bohrer, G.; Medvigy, D.; Ivanov, V. Y.; Vogel, C.; Curtis, P.

    2013-12-01

    Disturbances, either natural or anthropogenic, impact the carbon and water cycles. Therefore, understanding their immediate effect, as well as how fluxes evolve while forests recover from disturbances is essential to carbon and water cycle modeling. Our study area is located in northern Michigan and encompasses the mixed-deciduous forest surrounding the University of Michigan Biological Station (UMBS). The two AmeriFlux affiliated towers operated by the UMBS, one with an undisturbed footprint and a second overlooking the Forest Accelerated Succession ExperimenT (FASET) site, a 39 ha area where all aspen (Populus spp.) and birch (Betula papyrifera) trees were girdled, provides the supporting data for our study. We used the Ecosystem Demography model version 2 (ED2) to run three scenarios: a control (undisturbed) case, a homogeneous disturbance (dist-1) where 30% of the leaf area was removed regardless of functional type, and a FASET like disturbance (dist-2) where all early successional trees, which occupy 30% of leaf area, were removed. We parameterized ED2 using observations of monthly and yearly net ecosystem exchange (NEE), latent, and sensible heat fluxes from the undisturbed site (UMBS-AmeriFlux) from pre-disturbance years. We force the model using meteorological data recorded by the flux towers and evaluate the output of the three cases against NEE, latent, and sensible heat fluxes measured at the UMBS-AmeriFlux site (undisturbed case) and against the FASET tower (cases dist-1 and dist-2) after the disturbance occurred. Our results indicate that in such a case of an intermediate disturbance the results of the disturbance are defendant on the functional type that was affected. As a result of this study, we expect to improve the understanding of the role disturbances and the subsequent recovery on carbon and water fluxes of broadleaved deciduous forests.

  9. Recovery of trailside vegetation from trampling in a tropical rain forest

    NASA Astrophysics Data System (ADS)

    Boucher, Douglas H.; Aviles, Jeannette; Chepote, Rafael; Domínguez Gil, Oscar E.; Vilchez, Braulio

    1991-03-01

    Practically no information exists on the impact of human trampling on tropical rain forest vegetation. We studied three trails with varying periods of use and recovery in a tropical rain forest in Costa Rica. Human impact on trailside plants was curvilinearly related to use, as found by other workers in temperate zone vegetation. Recovery in a period of two years and eight months had been rapid, and herbs and seedlings were more abundant along the recovering trail than in undisturbed forest. The results imply that a shifting mosaic of trails, analogous to the mosaic created by light gaps, may be the best management technique to minimize the impact of human visitors in tropical rain forests.

  10. SAR backscatter from coniferous forest gaps

    NASA Technical Reports Server (NTRS)

    Day, John L.; Davis, Frank W.

    1992-01-01

    A study is in progress comparing Airborne Synthetic Aperture Radar (AIRSAR) backscatter from coniferous forest plots containing gaps to backscatter from adjacent gap-free plots. Issues discussed are how do gaps in the range of 400 to 1600 sq m (approximately 4-14 pixels at intermediate incidence angles) affect forest backscatter statistics and what incidence angles, wavelengths, and polarizations are most sensitive to forest gaps. In order to visualize the slant-range imaging of forest and gaps, a simple conceptual model is used. This strictly qualitative model has led us to hypothesize that forest radar returns at short wavelengths (eg., C-band) and large incidence angles (e.g., 50 deg) should be most affected by the presence of gaps, whereas returns at long wavelengths and small angles should be least affected. Preliminary analysis of 1989 AIRSAR data from forest near Mt. Shasta supports the hypothesis. Current forest backscatter models such as MIMICS and Santa Barbara Discontinuous Canopy Backscatter Model have in several cases correctly predicted backscatter from forest stands based on inputs of measured or estimated forest parameters. These models do not, however, predict within-stand SAR scene texture, or 'intrinsic scene variability' as Ulaby et al. has referred to it. For instance, the Santa Barbara model, which may be the most spatially coupled of the existing models, is not truly spatial. Tree locations within a simulated pixel are distributed according to a Poisson process, as they are in many natural forests, but tree size is unrelated to location, which is not the case in nature. Furthermore, since pixels of a simulated stand are generated independently in the Santa Barbara model, spatial processes larger than one pixel are not modeled. Using a different approach, Oliver modeled scene texture based on an hypothetical forest geometry. His simulated scenes do not agree well with SAR data, perhaps due to the simple geometric model used. Insofar as texture

  11. Forests & Trees.

    ERIC Educational Resources Information Center

    Gage, Susan

    1989-01-01

    This newsletter discusses the disappearance of the world's forests and the resulting environmental problems of erosion and flooding; loss of genetic diversity; climatic changes such as less rainfall, and intensifying of the greenhouse effect; and displacement and destruction of indigenous cultures. The articles, lessons, and activities are…

  12. Forest Imaging

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA's Technology Applications Center, with other government and academic agencies, provided technology for improved resources management to the Cibola National Forest. Landsat satellite images enabled vegetation over a large area to be classified for purposes of timber analysis, wildlife habitat, range measurement and development of general vegetation maps.

  13. Soil respiration in pits and mounds following an experimental forest blowdown

    SciTech Connect

    Millikin, C.S.; Bowden, R.D.

    1996-11-01

    Extensive uprooting of trees by windthrow can create areas of severe soil disturbance in temperate forests. Specifically, uprooted trees leave shaded pits and mounds of exposed roots and mineral soil. To assess the contribution of pit and mound microenvironments to overall soil respiration in an experimental hurricane blowdown at the Harvard Forest Long-Term Ecological Research site (MA), summer CO{sub 2} effluxes were measured on pit, mound, and undisturbed microsites. Mean CO{sub 2} effluxes were 45.4, 80.1, and 99.0 mgC m{sup -2} h{sup -1} for pit, mound, and control microsites, respectively. Although soil respiration is lower in areas of disturbed soil than in undisturbed areas, the total efflux contribution (5.3%) form pits and mounds to the overall flux rate at the site was small. The area-weighted soil respiration estimate is 3.1% lower than the estimate obtained using flux measurements from control locations alone. Measurements taken from undisturbed plots represent a small but systematic overestimate of soil respiration across the site. 25 refs., 1 fig.

  14. Disturbance-mediated accelerated succession in two Michigan forest types

    USGS Publications Warehouse

    Abrams, Marc D.; Scott, Michael L.

    1989-01-01

    In northern lower Michigan, logging accelerated sugar maple (Acer saccharum) dominance in a northern white cedar (Thuja occidentals) community, and clear-cutting and burning quickly converted certain sites dominated by mature jack pine (Pinus banksiana) to early-succesional hardwoods, including Prunus, Populus, and Quercus. In both forest types the succeeding hardwoods should continue to increase in the future at the expense of the pioneer conifer species. In the cedar example, sugar maple was also increasing a an undisturbed, old-growth stand, but at a much reduced rate than in the logged stand. Traditionally, disturbance was through to set back succession to some earlier stage. However, out study sites and at least several other North American forest communities exhibited accelerated succession following a wide range of disturbances, including logging fire, ice storms, wind-throw, disease, insect attack, and herbicide spraying.

  15. Forest succession in the Upper Rio Negro of Colombia and Venezuela

    SciTech Connect

    Saldarriaga, J.G.; West, D.C.; Tharp, M.L.

    1986-11-01

    Woody vegetation from 23 forest stands along the Upper Rio Negro of Venezuela and Colombia was sampled in 1982 to examine the hypothesis that the Amazon forest has been largely undisturbed since the Pleistocene, to quantify vegetation development during different stages of succession following agricultural development, and to determine the time required for a successional stand to become a mature forest. The ubiquitousness of charcoal in the tierra firme forest indicated the presence of fire associated with extreme dry periods and human disturbances. Changes in species composition, vegetation structure, and woody biomass were studied on 19 abandoned farms and four mature forest stands. Living and dead biomass for the tress and their components was determined by regression equations developed from measurements of harvested trees. The rate of recovery of floristic composition, structure, and biomass following disturbance is relatively slow. Aboveground dead biomass remained high 14 years after the forest was disturbed by the agricultural practices. The lowest dead biomass is reached 20 years after abandonment, and the largest values are found in mature forests. Data analysis of 80-year-old stands showed that the species composition approached that of a mature forest. Approximately 140 to 200 years was required for an abandoned farm to attain the basal area and biomass values comparable to those of a mature forest. The results of this study indicate that recovery is five to seven times longer in the Upper Rio Negro than it is in other tropical areas in South America.

  16. Measuring the hydraulic conductivity of soil adjacent to tile drains in a heavy clay soil in The Netherlands

    NASA Astrophysics Data System (ADS)

    Bouma, J.; Van Hoorn, J. W.; Stoffelsen, G. H.

    The hydraulic conductivity, Ksat, of soil adjacent to tile drains in heavy clay soils was measured at twelve locations with a new technique. This technique involves excavation of a cube of soil (25 cm × 25 cm × 25 cm) in situ around a tile fragment. Cutting of the tile leaves it protruding from the cube for ˜5 cm on two sides, also when covering five sides of the cube with a layer of gypsum outside the pit. Flow rates from the tile are measured for two conditions: (1) infiltration into the layer which was previously the lower horizontal soil surface of the cube; and (2) infiltration into the upper surface. The cube is turned upside down to allow the first measurement. The open surface is then covered with gypsum. The cube is turned upside down again and gypsum is removed from the upper surface of the cube (which is the original upper surface of the cube in the pit) to allow the second measurement. The first measurement mainly characterizes undisturbed soil below the drain, the second characterizes soil above the drain (fill). Dye is added to the percolating water to trace patterns of water movement, using micromorphometric techniques. Flow rates are transformed to Ksat-values by using an electrolytic analog model. Measured Ksat-values below the drain had median values of 10 m/day and agreed well with those measured in undisturbed soil at comparable depth, indicating that there are no changes due to either system construction or system operation. The median Ksat for fill above the drain was 5 m/day. The conclusions reached pertain to three types of drains, e.g., one fired-clay pipe and two types of plastic pipe. The dye studies showed that water movement occurred almost exclusively along larger planar voids (cracks), and hardly along channels (rootholes). Water-conducting voids were below 2% by volume.

  17. Overland flow and sediment delivery five years after timber harvest in a mixed conifer forest, Arizona, U.S.A.

    NASA Astrophysics Data System (ADS)

    Heede, Burchard H.

    1987-06-01

    Timber was harvested for the first time in a mixed conifer forest of the Arǐzona White Mountains in 1978-1979. Trees were harvested by patch cuts and group selection. Logs were yarded by crawler tractors. After harvest, 19 small subdrainages were equipped with runoff and sediment collectors. The forest floors in the subdrainages were classed as undisturbed, moderately disturbed, or severely disturbed. Severe disturbance, caused by logging and monitoring activities, was associated with a pre-existing erosion pavement that had developed for unknown reasons. Although overland flow and sediment delivery differed significantly between the severely disturbed and undisturbed groups during the 5 yr postharvest period, all quantities were practically insignificant. The group severely disturbed by logging had an average of only 0.006 mm yr -1 annual soil loss. Overland flows ranged between 0.7 and 15.4 mm yr -1 and sediment between 5.67 and 268.78 kg ha -1 yr -1. Summer yields of overland flow and sediment delivery were significantly higher than those in winter. Precipitation amounts were about equal for both seasons, but summer precipitation is of monsoon origin. Flow and sediment yields were not significantly different between moderately disturbed and undisturbed forest floor. Recovery from disturbance could not be detected.

  18. Agricultural legacies in forest environments: tree communities, soil properties, and light availability.

    PubMed

    Flinn, Kathryn M; Marks, P L

    2007-03-01

    Temperate deciduous forests across much of Europe and eastern North America reflect legacies of past land use, particularly in the diversity and composition of plant communities. Intense disturbances, such as clearing forests for agriculture, may cause persistent environmental changes that continue to shape vegetation patterns as landscapes recover. We assessed the long-term consequences of agriculture for environmental conditions in central New York forests, including tree community structure and composition, soil physical and chemical properties, and light availability. To isolate the effects of agriculture, we compared 20 adjacent pairs of forests that were never cleared for agriculture (primary forests) and forests that established 85-100 years ago on plowed fields (secondary forests). Tree communities in primary and secondary forests had similar stem density, though secondary forests had 14% greater basal area. Species composition differed dramatically between the two forest types, with primary forests dominated by Acer saccharum and Fagus grandifolia and secondary forests by Acer rubrum and Pinus strobus. Primary and secondary forests showed no consistent differences in soil physical properties or in the principal gradient of soil fertility associated with soil pH. Within stands, however, soil water content and pH were more variable in primary forests. Secondary forest soils had 15% less organic matter, 16% less total carbon, and 29% less extractable phosphorus in the top 10 cm than adjacent primary stands, though the ranges of the forest types mostly overlapped. Understory light availability in primary and secondary forests was similar. These results suggest that, within 100 years, post-agricultural stands have recovered conditions comparable to less disturbed forests in many attributes, including tree size and number, soil physical properties, soil chemical properties associated with pH, and understory light availability. The principal legacies of

  19. 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.

  20. Idiosyncratic responses of Amazonian birds to primary forest disturbance.

    PubMed

    Moura, Nárgila G; Lees, Alexander C; Aleixo, Alexandre; Barlow, Jos; Berenguer, Erika; Ferreira, Joice; Mac Nally, Ralph; Thomson, James R; Gardner, Toby A

    2016-03-01

    As humans continue to alter tropical landscapes across the world, it is important to understand what environmental factors help determine the persistence of biodiversity in modified ecosystems. Studies on well-known taxonomic groups can offer critical insights as to the fate of biodiversity in these modified systems. Here we investigated species-specific responses of 44 forest-associated bird species with different behavioural traits to forest disturbance in 171 transects distributed across 31 landscapes in two regions of the eastern Brazilian Amazon. We investigated patterns of species occurrence in primary forests varyingly disturbed by selective-logging and fire and examined the relative importance of local, landscape and historical environmental variables in determining species occurrences. Within undisturbed and disturbed primary forest transects, we found that distance to forest edge and the biomass of large trees were the most important predictors driving the occurrence of individual species. However, we also found considerable variation in species responses to different environmental variables as well as inter-regional variation in the responses of the same species to the same environmental variables. We advocate the utility of using species-level analyses to complement community-wide responses in order to uncover highly variable and species-specific responses to environmental change that remain so poorly understood.

  1. Hydrodispersive characterization of a sandy porous medium by tracer tests carried out in laboratory on undisturbed soil samples

    NASA Astrophysics Data System (ADS)

    Ferrante, Aldo Pedro; Fallico, Carmine; Rios, Ana C.; Fernanda Rivera, Maria; Santillan, Patricio; Salazar, Mario

    2013-04-01

    The contamination of large areas and correspondent aquifers often imposes to implement some recovery operations which are generally complex and very expensive. Anyway, these interventions necessarily require the preventive characterization of the aquifers to be reclaimed and in particular the knowledge of the relevant hydrodispersive parameters. The determination of these parameters requires the implementation tracer tests for the specific site (Sauty JP, 1978). To reduce cost and time that such test requires tracer tests on undisturbed soil samples, representative of the whole aquifer, can be performed. These laboratory tests are much less expensive and require less time, but the results are certainly less reliable than those obtained by field tests for several reasons, including the particular scale of investigation. In any case the hydrodispersive parameters values, obtained by tests carried out in laboratory, can provide useful information on the considered aquifer, allowing to carry out initial verifications on the transmission and propagation of the pollutants in the aquifer considered. For this purpose, tracer tests with inlet of short time were carried out in the Soil Physics Laboratory of the Department of Soil Protection (University of Calabria), on a series of sandy soil samples with six different lengths, repeating each test with three different water flow velocities (5 m/d; 10 m/s and 15 m/d) (J. Feyen et al., 1998). The lengths of the samples taken into account are respectively 15 cm, 24 cm, 30 cm, 45 cm, 60 cm and 75 cm, while the solution used for each test was made of 100 ml of water and NaCl with a concentration of this substance corresponding to 10 g/L. For the porous medium taken into consideration a particle size analysis was carried out, resulting primarily made of sand, with total porosity equal to 0.33. Each soil sample was placed in a flow cell in which was inlet the tracer from the bottom upwards, measuring by a conductivimeter the

  2. Discriminating Natural Variation from Legacies of Disturbance in Semi-Arid Forests, Southwestern USA

    NASA Astrophysics Data System (ADS)

    Swetnam, T. L.; Lynch, A. M.; Falk, D. A.; Yool, S. R.; Guertin, D. P.

    2014-12-01

    Characterizing differences in existing vegetation driven by natural variation versus disturbance legacies could become a critical component of applied forest management practice with important implications for monitoring ecologic succession and eco-hydrological interactions within the critical zone. Here we characterize variations in aerial LiDAR derived forest structure at individual tree scale in Arizona and New Mexico. Differences in structure result from both topographic and climatological variations and from natural and human related disturbances. We chose a priori undisturbed and disturbed sites that included preservation, development, logging and wildfire as exemplars. We compare two topographic indices, the topographic position index (TPI) and topographic wetness index (TWI), to two local indicators of spatial association (LISA): the Getis-Ord Gi and Anselin's Moran I. We found TPI and TWI correlate well to positive z-scores (tall trees in tall neighborhoods) in undisturbed areas and that disturbed areas are clearly defined by negative z-scores, in some cases better than what is visible from traditional orthophotography and existing GIS maps. These LISA methods also serve as a robust technique for creating like-clustered stands, i.e. common stands used in forest inventory monitoring. This research provides a significant advancement in the ability to (1) quantity variation in forest structure across topographically complex landscapes, (2) identify and map previously unrecorded disturbance locations, and (3) quantify the different impacts of disturbance within the perimeter of a stand or event at ecologically relevant scale.

  3. Examining shifts in Carabidae assemblages across a forest-agriculture ecotone.

    PubMed

    Leslie, T W; Biddinger, D J; Rohr, J R; Hulting, A G; Mortensen, D A; Fleischer, S J

    2014-02-01

    Northeastern U.S. farms are often situated adjacent to forestland due to the heterogeneous nature of the landscape. We investigated how forested areas influence Carabidae diversity within nearby crop fields by establishing transects of pitfall traps. Trapping extended across a forest-agriculture ecotone consisting of maize, an intermediate mowed grass margin, and a forest edge. Carabidae diversity was compared among the three habitats, and community and population dynamics were assessed along the transect. We used a principal response curve to examine and visualize community change across a spatial gradient. The highest levels of richness and evenness were observed in the forest community, and carabid assemblages shifted significantly across the ecotone, especially at the forest-grass interface. Despite strong ecotone effects, population distributions showed that some species were found in all three habitats and seemed to thrive at the ecotone. Based on similarity indices, carabid assemblages collected in maize adjacent to forest differed from carabid assemblages in maize not adjacent to forest. We conclude that forest carabid assemblages exhibit high degrees of dissimilarity with those found in agricultural fields and forested areas should thus be retained in agricultural landscapes to increase biodiversity at the landscape scale. However, ecotone species found at forest edges can still noticeably influence carabid community composition within neighboring agricultural fields. Further studies should determine how these shifts in carabid assemblages influence agroecosystem services in relation to ecosystem services observed in fields embedded in an agricultural matrix.

  4. Impacts of insect-related forest mortality on hydrologic partitioning and forest productivity in the Southern Rocky Mountains, USA

    NASA Astrophysics Data System (ADS)

    Molotch, N. P.

    2014-12-01

    Recent large-scale changes in forest cover over Western North America associated with insect-related forest mortality may have widespread impacts on water availability. These changes have potentially varied impacts on water availability as forest mortality influences rates of snow accumulation, snowmelt, and evapotranspiration. These changes may significantly alter runoff production and gross primary productivity in mountain forests. Analysis of remotely sensed vegetation greenness data indicate strong forest and understory growth dependencies associated with snow accumulation and snowmelt with peak snow water equivalent explaining 40-50% of inter-annual greenness variability in the Rocky Mountains. Examples of these dependencies will be presented based on the 2012 drought in the Southwestern US whereby near record low snow accumulation and record high potential evapotranspiration have resulted in record low forest greening as evident in the 30+ year satellite record. Forest response to aridity in 2012 was exacerbated by forest disturbance with greenness anomalies 90% greater in magnitude in Bark Beetle and Spruce Budworm affected areas versus undisturbed areas and 182% greater in magnitude in areas impacted by fire. Growing season length was inversely proportional to peak greenness with record high Normalized Difference Vegetation Index (NDVI) values in April (14% above average) corresponding with record low NDVI values in July (7% below average). Gross primary productivity (GPP) estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) and from the Niwot Ridge, Colorado Ameriflux tower indicate record high April GPP (30% and 90% above average for MODIS and the tower, respectively) correspodning with record low July GPP (19% and 30% below average, respectively). Differences in these energy, water, ecosystem relationships among difference distrurbance regimes indicate that the sensitivity of ecosystems to changes in climate is heavily dependent on

  5. 75 FR 47755 - Black Hills National Forest, Mystic Ranger District, South Dakota, Pactola Project Area

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ... including forest resources from an existing insect and disease epidemic (mountain pine beetle), creating a... forest resources, from the existing insect and disease (mountain pine beetle) epidemic. Restore resource... focused on reducing insects or disease on public and adjacent private lands, and reducing the...

  6. Dispersal of forest insects

    NASA Technical Reports Server (NTRS)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  7. The I.A.G. / A.I.G. SEDIBUD Book Project: Source-to-Sink Fluxes in Undisturbed Cold Environments

    NASA Astrophysics Data System (ADS)

    Beylich, Achim A.; Dixon, John C.; Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). Amplified climate change and ecological sensitivity of largely undisturbed polar and high-altitude cold climate environments have been highlighted as key global environmental issues. The effects of projected climate change will change surface environments in cold regions and will alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment in these largely undisturbed environments is acute. Our book addresses this existing key knowledge gap. The applied approach of integrating comparable and longer-term field datasets on contemporary solute and sedimentary fluxes from a number of different defined cold climate catchment geosystems for better understanding (i) the environmental drivers and rates of contemporary denudational surface processes and (ii) possible effects of projected climate change in cold regions is unique in the field of geomorphology. Largely undisturbed cold climate environments can provide baseline data for modeling the effects of environmental change. The book synthesizes work carried out by numerous SEDIBUD Members over the last decade in numerous cold climate catchment geosystems worldwide. For reaching a global cover of different cold climate environments the book is - after providing an introduction part and a basic part on climate change in cold environments and general implications for solute and sedimentary fluxes - dealing in different

  8. Valuation of forested buffers

    NASA Astrophysics Data System (ADS)

    Basnyat, Prakash

    The research concentrated on two fronts: (1) defining relationships between land use complex and nitrate and sediment concentrations; and (2) developing a method for assessing the extent of potential and water quality improvements available through land management options and their associated costs. In this work, selected basins of the Fish River (Alabama) were delineated, land use/land cover types were classified, and "contributing zones" were delineated using Geographic Information System (GIS) and Remote Sensing (RS) analytical tools. Water samples collected from these basins were analyzed for their nutrient contents. Based on measured nitrate and sediment concentrations in basin streams, a linkage model was developed. This linkage model relates land use/land cover with the pollution levels in the stream. The linkage model was evaluated at three different scales: (1) the basin scale; (2) the contributing zone scale; and (3) the stream buffer/riparian zone scale. The contributing zone linkage model suggests that forests act as a sink or transformation zone. Residential/urban/built-up areas were identified as the strongest contributors of nitrate in the contributing zones model and active agriculture was identified as the second largest contributor. Regression results for the "land use/land cover diversity" model (stream buffer/riparian zone scale) suggest that areas that are close (adjacent) to the stream and any disturbances in these areas will have major impacts on stream water quality. The economic model suggests the value of retiring lands from agricultural land uses to forested buffers varies from 0 to 3067 per hectare, depending on the types of crops currently grown. Along with conversion costs, this land value forms the basis for estimates of the costs of land management options for improving (or maintaining) water quality throughout the study area. The model also shows the importance of stream-side management zones, which are key to maintenance of stream

  9. Consistent, small effects of treefall disturbances on the composition and diversity of four Amazonian forests.

    PubMed

    Baker, Timothy R; Vela Díaz, Dilys M; Chama Moscoso, Victor; Navarro, Gilberto; Monteagudo, Abel; Pinto, Ruy; Cangani, Katia; Fyllas, Nikolaos M; Lopez Gonzalez, Gabriela; Laurance, William F; Lewis, Simon L; Lloyd, Jonathan; Ter Steege, Hans; Terborgh, John W; Phillips, Oliver L

    2016-03-01

    Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance.We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots.Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests.Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems.

  10. Variations in dung beetles assemblages (Coleoptera: Scarabaeidae) within two rain forest habitats in French Guiana.

    PubMed

    Feer, François

    2013-06-01

    The structure of dung beetle communities inhabiting tropical forests are known to be sensitive to many kinds of environmental changes such as microclimate related to vegetation structure. I examined Scarabaeinae assemblages in two sites of undisturbed high forest and two sites of low forest forming a transitional zone with the open habitat of an inselberg in French Guiana. Sampling was made with pitfall and flight interception traps during 2003 and 2004. The driest and warmest conditions characterized the low forest sites. Across two years we obtained 2 927 individuals from 61 species with pitfall traps and 1 431 individuals from 85 species with flight interception traps. Greater species richness and abundance characterized all sites sampled with pitfall traps during 2003 more than 2004. In 2003 no differences were detected among sites by rarefaction analyses. In 2004 the species richest high forest site was significantly different from one of the low forest sites. For both years Clench model asymptotes for species richness were greater in high forest than in low forest sites. For both years, mean per-trap species richness, abundance and biomass among high forest sites were similar and higher than in low forest sites, especially where the lowest humidity and the highest temperature were recorded. Within the two low forest sites, species richness and abundance recorded during the second year, decreased with distance to edge. Different dominant roller species characterized the pitfall samples in one site of low forest and in other sites. Small variations in microclimatic conditions correlated to canopy height and openness likely affected dung beetle assemblages but soil depth and the presence of large mammals providing dung resource may also play a significant role.

  11. Drought as a Determinant of Tropical Montane Forest Line Position

    NASA Astrophysics Data System (ADS)

    Giambelluca, T. W.; Crausbay, S.; Hotchkiss, S.; Gotsch, S. G.; Frazier, A. G.; Longman, R. J.

    2014-12-01

    Globally, the upper elevation margins of montane forests follow a latitudinal pattern, ranging from below 1000 m at high latitudes to above 3000 m on continental tropical mountains. Forest lines on oceanic islands are distinctly lower, but are also latitude dependent. While proposed mechanisms to explain forest line position are generally related to effects of low temperature, including tissue damage from freezing and slow growth, aridity has been suggested as a possible cause of the lower oceanic island forest lines. A relatively undisturbed forest line is found on Haleakalā Volcano, on the Island of Maui at an elevation of around 2000 m. Forest on Haleakalā does not appear to be limited by low temperature; mean annual temperature at the forest line (8.8-10.5°C) is well above the suggested threshold growing season temperature. Instead, the position of this ecotone coincides with the mean elevation of the trade wind inversion (TWI), which separates the moist marine atmospheric layer from arid upper air. Abrupt changes in moisture-related climate variables are found at the TWI, including one of the steepest mean annual rainfall gradients in the world. In recent work, microclimate during drought was shown to play a critical role in structuring the Haleakalā forest line, the position of which was most strongly related to relative humidity during a strong El Niño-induced drought. The relationship between El Niño-driven drought and ecotone position was tested in long-term paleoecological data. Reconstructions of the cloud forest's upper limit and moisture balance over the past 3,300 years were strongly associated with paleorecords of El Niño event frequency. The forest ecotone may be particularly responsive to strong, short-duration drought events because taxa here, particularly the isohydric dominant canopy tree Metrosideros polymorpha, are near their physiological limits. Minimum leaf water potential in M. polymorpha near the forest line is close to the turgor

  12. Protected areas: mixed success in conserving East Africa's evergreen forests.

    PubMed

    Pfeifer, Marion; Burgess, Neil D; Swetnam, Ruth D; Platts, Philip J; Willcock, Simon; Marchant, Robert

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at -9.3% (17,167 km(2)), but varied between countries (range: -0.9% to -85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa's forest conservation efforts.

  13. Learning Non-Adjacent Regularities at Age 0 ; 7

    ERIC Educational Resources Information Center

    Gervain, Judit; Werker, Janet F.

    2013-01-01

    One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: "wo fe fe" and non-adjacent repetitions, ABA: "wo fe wo", respectively; Marcus et al., 1999). One unexplored issue is…

  14. View of north side from exterior stairs of adjacent building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of north side from exterior stairs of adjacent building, bottom cut off by fringed buildings, view facing south-southwest - U.S. Naval Base, Pearl Harbor, Industrial X-Ray Building, Off Sixth Street, adjacent to and south of Facility No. 11, Pearl City, Honolulu County, HI

  15. A Study of the Pronunciation of Words Containing Adjacent Vowels.

    ERIC Educational Resources Information Center

    Greif, Ivo P.

    To determine the usefulness of the commonly taught phonics rule, "only pronounce the first vowel in words that contain adjacent vowels" (the VV rule, with the first "v" pronounced with the long vowel sound), two new studies applied it to words with adjacent vowels in several lists and dictionaries. The first study analyzed words containing…

  16. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  17. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  18. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  19. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  20. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  1. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  2. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  3. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  4. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  5. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  6. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  7. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  8. An evaluation of imaging spectrometry for estimating forest canopy chemistry

    NASA Technical Reports Server (NTRS)

    Wessman, Carol A.; Aber, John D.; Peterson, David L.

    1989-01-01

    High spectral resolution Airborne Imaging Spectrometer (AIS) data were acquired over 20 well-studied Wisconsin forest sites to evaluate the potential of remote sensing for estimating forest canopy chemistry. Intensive nutrient cycling research in these forests demonstrates that canopy lignin content is strongly related to measured annual nitrogen mineralization at the undisturbed sites and may serve as an accurate index for nitrogen cycling rates. Ground measurements were made of foliar biomass and canopy nitrogen and lignin content, the latter within two weeks of the AIS overflight. The spectral data were transformed using derivative techniques modified from laboratroy spectroscopy. Stepwise regression assisted in determining combinations of wavelengths most highly correlated with canopy chemistry and biomass. Strong correlations between AIS data and total canopy lignin content in deciduous forests and canopy lignin concentration (total lignin/biomass) in both deciduous and coniferous stands indicate that imaging spectrometry can be used to estimate canopy lignin content and, from that, the spatial distribution of annual nitrogen mineralization rates.

  9. Montana's forest resources. Forest Service resource bulletin

    SciTech Connect

    Conner, R.C.; O'Brien, R.A.

    1993-09-01

    The report includes highlights of the forest resource in Montana as of 1989. Also the study describes the extent, condition, and location of the State's forests with particular emphasis on timberland. Includes statistical tables, area by land classes, ownership, and forest type, growing stock and sawtimber volumes, growth, mortality, and removals for timberland.

  10. Spatiotemporal dynamics of forest fragmentation and its potential implications for carbon dynamics in the Brazilian Amazon between 2001 and 2010

    NASA Astrophysics Data System (ADS)

    Numata, I.; Cochrane, M.

    2012-12-01

    , emits the largest amount of carbon unit area of forest edge (4.7Mg/km2), while overall edge-related carbon across the Amazon is 2.7 Mg/km2. Our results indicate that the Brazilian Amazon now largely consists of two contrasting forest conditions: protected areas with vast undisturbed forests and unprotected forests that are highly fragmented and disturbed landscapes.

  11. Role of Nurse Logs in Forest Expansion at Timberline

    NASA Astrophysics Data System (ADS)

    Johnson, A. C.; Yeakley, A.

    2008-12-01

    Nurselogs, known to be key sites of forest regeneration in lower elevation temperate forests, may be important sites for seedling establishment at expanding timberline forests. To determine factors associated with seedling establishment and survival on nurselogs at timberline, fourteen sites, located across a precipitation gradient in the Washington North Cascades Mountains, were examined. Site attributes including seedling type and height, disturbance process introducing downed wood, wood decay type, shading, slope gradient, aspect, and temperature and water content of wood and adjacent soil were determined along 60 m long transects. Nurselogs were found at 13 out of 14 sites; sites typically associated with greater than 80% shade and downed wood having a high level of wood decay. Downed wood serving as nurselogs originated from blowdown, snow avalanches, and forest fires. In total, 46 of 136 downed wood pieces observed served as nurselogs. Seedlings on nurselogs included mountain hemlock (Tsuga mertensiana), Pacific silver fir (Abies amabilis), yellow cedar (Chamaecyparis nootkatensis), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and western larch (Larix occidentalis). Nurselogs had significantly higher temperatures (p = 0.015) and higher moisture contents (p = 0.019) than the adjacent soil. Per equal volumes weighed, nurselogs had on average of 23.8 g more water than the adjacent soil. Given predictions of climate warming and associated summer drought conditions in Pacific Northwest forests, the moisture provided by nurselogs may be integral for conifer survival and subsequent timberline expansion in some landscapes.

  12. Carbon and water fluxes from ponderosa pine forests disturbed by wildfire and thinning.

    PubMed

    Dore, S; Kolb, T E; Montes-Helu, M; Eckert, S E; Sullivan, B W; Hungate, B A; Kaye, J P; Hart, S C; Koch, G W; Finkral, A

    2010-04-01

    Disturbances alter ecosystem carbon dynamics, often by reducing carbon uptake and stocks. We compared the impact of two types of disturbances that represent the most likely future conditions of currently dense ponderosa pine forests of the southwestern United States: (1) high-intensity fire and (2) thinning, designed to reduce fire intensity. High-severity fire had a larger impact on ecosystem carbon uptake and storage than thinning. Total ecosystem carbon was 42% lower at the intensely burned site, 10 years after burning, than at the undisturbed site. Eddy covariance measurements over two years showed that the burned site was a net annual source of carbon to the atmosphere whereas the undisturbed site was a sink. Net primary production (NPP), evapotranspiration (ET), and water use efficiency were lower at the burned site than at the undisturbed site. In contrast, thinning decreased total ecosystem carbon by 18%, and changed the site from a carbon sink to a source in the first posttreatment year. Thinning also decreased ET, reduced the limitation of drought on carbon uptake during summer, and did not change water use efficiency. Both disturbances reduced ecosystem carbon uptake by decreasing gross primary production (55% by burning, 30% by thinning) more than total ecosystem respiration (TER; 33-47% by burning, 18% by thinning), and increased the contribution of soil carbon dioxide efflux to TER. The relationship between TER and temperature was not affected by either disturbance. Efforts to accurately estimate regional carbon budgets should consider impacts on carbon dynamics of both large disturbances, such as high-intensity fire, and the partial disturbance of thinning that is often used to prevent intense burning. Our results show that thinned forests of ponderosa pine in the southwestern United States are a desirable alternative to intensively burned forests to maintain carbon stocks and primary production.

  13. Multicriteria evaluation of simulated logging scenarios in a tropical rain forest.

    PubMed

    Huth, Andreas; Drechsler, Martin; Köhler, Peter

    2004-07-01

    Forest growth models are useful tools for investigating the long-term impacts of logging. In this paper, the results of the rain forest growth model FORMIND were assessed by a multicriteria decision analysis. The main processes covered by FORMIND include tree growth, mortality, regeneration and competition. Tree growth is calculated based on a carbon balance approach. Trees compete for light and space; dying large trees fall down and create gaps in the forest. Sixty-four different logging scenarios for an initially undisturbed forest stand at Deramakot (Malaysia) were simulated. The scenarios differ regarding the logging cycle, logging method, cutting limit and logging intensity. We characterise the impacts with four criteria describing the yield, canopy opening and changes in species composition. Multicriteria decision analysis was used for the first time to evaluate the scenarios and identify the efficient ones. Our results plainly show that reduced-impact logging scenarios are more 'efficient' than the others, since in these scenarios forest damage is minimised without significantly reducing yield. Nevertheless, there is a trade-off between yield and achieving a desired ecological state of logged forest; the ecological state of the logged forests can only be improved by reducing yields and enlarging the logging cycles. Our study also demonstrates that high cutting limits or low logging intensities cannot compensate for the high level of damage caused by conventional logging techniques.

  14. Effects of soil structural development on soil hydraulic properties and hydraulic processes in forested hillslopes

    NASA Astrophysics Data System (ADS)

    Hayashi, Y.; Kosugi, K.; Mizuyama, T.

    2010-12-01

    We evaluated the effects of the forest soil on flood and drought mitigation, and decrease of the danger of slope failures. Forest soils usually contain a primary textural pore system, which is determined by solid particle-size distribution and particle arrangements, accompanied by a secondary structural pore system formed by the effects of forest ecosystems. With this background, we investigated the effects of the pore structural development on the unsaturated hydraulic properties and rainwater dynamics on a forested hillslope. The undisturbed soil samples were collected from an entire forested hillslope. The undisturbed soils contain the primary and secondary pore systems, and were set to be as structural developed soils. The water retention curve and saturated hydraulic conductivity of each sample were measured. After that, each undisturbed soil was crushed to break up aggregate structure and packed into core sampler to prepare the structural undeveloped soil. We conducted same measurement of the structural undeveloped soils as those used for the structural developed soils. Generally, compared with the structural undeveloped soils, the structural developed soils had large median pore radius and width of pore size distribution, and large saturated hydraulic conductivity. We conducted 2-dimentional numerical simulations of hydraulic processes on a forested hillslope with the code programmed by Kosugi (2007), using the data sets of the structural developed and undeveloped soils. The peak flow of stream is formed by the direct discharge from the lower end of the slope, and the base flow is formed by the seepage into the bedrock (Kosugi, 2007). Furthermore, slope failure are caused by the positive pore water pressure in the soil layer. Therefore, for evaluating the effect of forest soil on hydraulic processes, we estimated the discharge rate of the lower end of the slope and the rate of the seepage into the bedrock from the soil layer, and the matric pressure head. As

  15. Forest edges have high conservation value for bird communities in mosaic landscapes.

    PubMed

    Terraube, Julien; Archaux, Frédéric; Deconchat, Marc; van Halder, Inge; Jactel, Hervé; Barbaro, Luc

    2016-08-01

    A major conservation challenge in mosaic landscapes is to understand how trait-specific responses to habitat edges affect bird communities, including potential cascading effects on bird functions providing ecosystem services to forests, such as pest control. Here, we examined how bird species richness, abundance and community composition varied from interior forest habitats and their edges into adjacent open habitats, within a multi-regional sampling scheme. We further analyzed variations in Conservation Value Index (CVI), Community Specialization Index (CSI) and functional traits across the forest-edge-open habitat gradient. Bird species richness, total abundance and CVI were significantly higher at forest edges while CSI peaked at interior open habitats, i.e., furthest from forest edge. In addition, there were important variations in trait- and species-specific responses to forest edges among bird communities. Positive responses to forest edges were found for several forest bird species with unfavorable conservation status. These species were in general insectivores, understorey gleaners, cavity nesters and long-distance migrants, all traits that displayed higher abundance at forest edges than in forest interiors or adjacent open habitats. Furthermore, consistently with predictions, negative edge effects were recorded in some forest specialist birds and in most open-habitat birds, showing increasing densities from edges to interior habitats. We thus suggest that increasing landscape-scale habitat complexity would be beneficial to declining species living in mosaic landscapes combining small woodlands and open habitats. Edge effects between forests and adjacent open habitats may also favor bird functional guilds providing valuable ecosystem services to forests in longstanding fragmented landscapes.

  16. Effects of habitat disruption on the activity of nectarivorous bats (Chiroptera: Phyllostomidae) in a dry tropical forest: implications for the reproductive success of the neotropical tree Ceiba grandiflora.

    PubMed

    Quesada, Mauricio; Stoner, Kathryn E; Rosas-Guerrero, Víctor; Palacios-Guevara, Carolina; Lobo, Jorge A

    2003-05-01

    In the tropical dry forest of the central Pacific coast of Mexico the pollination and reproductive success of the bombacaceous tree Ceiba grandiflora was negatively affected by habitat disruption. Two of the three bat species that function as effective pollinators for this species ( Glossophaga soricina and Musonycteris harrisoni) visited flowers found in trees in disturbed habitats significantly less than trees found in undisturbed habitats. A similar pattern was observed for the effective bat pollinator, Leptonycteris curasoae; however the difference was not significant. The three nectarivorous bats that functioned as effective pollinators of C. grandiflora also visited flowers to exclusively feed on pollen by biting or pulling off an anther (see Fig. S1 of Electronic Supplementary Material). The number of pollen grains deposited on stigmas from flowers in undisturbed areas was significantly greater than from flowers in disturbed habitats. The greater visitation rate and the greater number of pollen grains deposited on flowers from trees in undisturbed forest resulted in a significantly greater fruit set for trees in these areas. Our study demonstrates the negative effect that habitat disruption has on bat pollinators in tropical dry forest ecosystems and documents the negative consequences for the plants they pollinate.

  17. Slopewash, surface runoff and fine-litter transport in forest and landslide scars in humid-tropical steeplands, Luquillo Experimental Forest, Puerto Rico

    USGS Publications Warehouse

    Larsen, M.C.; Torres-Sanchez, A. J.; Concepcion, I.M.

    1999-01-01

    Rainfall, slopewash (the erosion of soil particles), surface runoff and fine-litter transport at humid-tropical steepland sites in the Luquillo Experimental Forest, Puerto Rico (18??20' N, 65??45' W) were measured from 1991 to 1995. Hillslopes underlain by (1) Cretaceous tuffaceous sandstone and siltstone in subtropical rain (tabonuco) forest with vegetation recovering from Hurricane Hugo (1989), and (2) Tertiary quartz diorite in subtropical lower montane wet (colorado and dwarf) forest with undisturbed forest canopy were compared to recent landslide scars. Monthly surface runoff on these very steep hillslopes (24??to 43??) was only 0.2 to 0.5 per cent of monthly rainfall. Slopewash was higher in sandy loam soils whose parent material is quartz diorite (averaging 46 g m-2 a-1) than in silty clay loam soils derived from tuffaceous sandstone and siltstone where the average was 9 g m-2 a-1. Annual slopewash of 100 to 349 g m-2 on the surfaces of two recent, small landslide scars was measured initially but slopewash decreased to only 3 to 4 g m-2 a-1 by the end of the study. The mean annual mass of fine litter (mainly leaves and twigs) transported downslope at the forested sites ranged from 5 to 8 g m-2 and was lower at the tabonuco forest site, where post-Hurricane Hugo recovery is still in progress. Mean annual fine-litter transport was 2.5 g m-2 on the two landslide scars.

  18. Forest Health Detectives

    ERIC Educational Resources Information Center

    Bal, Tara L.

    2014-01-01

    "Forest health" is an important concept often not covered in tree, forest, insect, or fungal ecology and biology. With minimal, inexpensive equipment, students can investigate and conduct their own forest health survey to assess the percentage of trees with natural or artificial wounds or stress. Insects and diseases in the forest are…

  19. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    SciTech Connect

    Kaser, L.; Karl, T.; Guenther, A.; Graus, M.; Schnitzhofer, R.; Turnipseed, A.; Fischer, L.; Harley, P.; Madronich, M.; Gochis, D.; Keutsch, F. N.; Hansel, A.

    2013-01-01

    We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass-spectrometer (PTR-TOFMS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration ompounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1mgcompoundm-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50 %), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10 %). The total MBO+isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of 20 monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site specific leaf cuvette measurements. While the modelled and measured MBO+isoprene fluxes agree well the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to storms, are

  20. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    NASA Astrophysics Data System (ADS)

    Kaser, L.; Karl, T.; Guenther, A.; Graus, M.; Schnitzhofer, R.; Turnipseed, A.; Fischer, L.; Harley, P.; Madronich, M.; Gochis, D.; Keutsch, F. N.; Hansel, A.

    2013-12-01

    We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration compounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks, including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters, showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1 mg compound m-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50%), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10%). The total MBO + isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light- and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site-specific leaf cuvette measurements. While the modeled and measured MBO + isoprene fluxes agree well, the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to

  1. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    NASA Astrophysics Data System (ADS)

    Kaser, L.; Karl, T.; Guenther, A.; Graus, M.; Schnitzhofer, R.; Turnipseed, A.; Fischer, L.; Harley, P.; Madronich, M.; Gochis, D.; Keutsch, F. N.; Hansel, A.

    2013-06-01

    We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass-spectrometer (PTR-TOF-MS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration compounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1 mg compound m-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50%), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10%). The total MBO + isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site specific leaf cuvette measurements. While the modelled and measured MBO + isoprene fluxes agree well the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to storms

  2. Are historical pollution events on the Delaware River recorded as geochemical marker horizons in adjacent marsh sediments

    SciTech Connect

    Walsh, R.; Yemane, K. . Dept. of Geology Bryn Mawr Coll., PA . Geology Dept.)

    1993-03-01

    In the last two hundred years of massive population and industrial growth, the Delaware River has been subjected to several minor and major pollutions. For example, as recently as June 1989 the tanker Presidente Rivera spilled an estimated hundred thousand to million gallons of oil into the river. In the Lower Delaware Basin tides affect the river and its tributaries up to a hundred kilometers inland. The freshwater marshes adjacent to the creeks that empty into the Delaware River experience diurnal tidal sedimentation. It is thus expected that the pollutants in the waterway would be transported via the tidal channels into the adjacent wetlands. The high sedimentation rate, clay-rich sediments, accumulation of terrestrial organic matter, and the low energy environments in these marshes should ensure rapid burial which may preserve some of the contaminants transported into the marshes. To test this hypothesis the authors selected a freshwater marsh along the Raccoon Creek just south of Philadelphia in New Jersey, and collected a 2 m core from a relatively undisturbed portion of the marsh, about 15 m away from the tidal channels. The pH averages around 6.2, ranges from 5.5--6.8, but, is slightly higher in the middle part of the core. The bulk mineralogy comprises chlorite, illite, kaolinite, feldspars and quartz. Vivianite and vermiculite were observed at places lower in the core. Graminae dominates the pollen/spore taxa. The organic debris is unaltered throughout the core. The authors will measure heavy metals and toxic chemicals on < 2[mu]m clay fractions. Also pristane/phytane ratios, indicative of hydrocarbons (crude oils), will be determined on organic matter extracts. The authors will compare and correlate the results to historically documented events of chemical and petroleum spills on the Delaware River.

  3. PIXE analysis of elements in gastric cancer and adjacent mucosa

    NASA Astrophysics Data System (ADS)

    Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

    1990-04-01

    The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

  4. Thermoelastic response of thin metal films and their adjacent materials

    SciTech Connect

    Kang, S.; Yoon, Y.; Kim, J.; Kim, W.

    2013-01-14

    A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

  5. Uncertainty and sensitivity analysis for two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant: Undisturbed conditions

    SciTech Connect

    HELTON,JON CRAIG; BEAN,J.E.; ECONOMY,K.; GARNER,J.W.; MACKINNON,ROBERT J.; MILLER,JOEL D.; SCHREIBER,JAMES D.; VAUGHN,PALMER

    2000-05-19

    Uncertainty and sensitivity analysis results obtained in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented for two-phase flow the vicinity of the repository under undisturbed conditions. Techniques based on Latin hypercube sampling, examination of scatterplots, stepwise regression analysis, partial correlation analysis and rank transformation are used to investigate brine inflow, gas generation repository pressure, brine saturation and brine and gas outflow. Of the variables under study, repository pressure is potentially the most important due to its influence on spallings and direct brine releases, with the uncertainty in its value being dominated by the extent to which the microbial degradation of cellulose takes place, the rate at which the corrosion of steel takes place, and the amount of brine that drains from the surrounding disturbed rock zone into the repository.

  6. Long-term temporal trends and estimated transmission rates for Mycobacterium bovis infection in an undisturbed high-density badger (Meles meles) population.

    PubMed

    Delahay, R J; Walker, N; Smith, G C; Smith, G S; Wilkinson, D; Clifton-Hadley, R S; Cheeseman, C L; Tomlinson, A J; Chambers, M A

    2013-07-01

    We describe epidemiological trends in Mycobacterium bovis infection in an undisturbed wild badger (Meles meles) population. Data were derived from the capture, clinical sampling and serological testing of 1803 badgers over 9945 capture events spanning 24 years. Incidence and prevalence increased over time, exhibiting no simple relationship with host density. Potential explanations are presented for a marked increase in the frequency of positive serological test results. Transmission rates (R0) estimated from empirical data were consistent with modelled estimates and robust to changes in test sensitivity and the spatial extent of the population at risk. The risk of a positive culture or serological test result increased with badger age, and varied seasonally. Evidence consistent with progressive disease was found in cubs. This study demonstrates the value of long-term data and the repeated application of imperfect diagnostic tests as indices of infection to reveal epidemiological trends in M. bovis infection in badgers.

  7. Forest and woodland depletion in the Lake Elementeita Basin, Kenya.

    PubMed

    Mwaura, F; Moore, T R

    1991-01-01

    Research geographers combined LANDSAT imagery analysis and vegetation survey (LANDSAT data interpretation, ground truthing, and quantitative transect sampling) to study the spatial dynamics of forest and woodland areas in the Lake Elementeita watershed in the central Rift Valley of Kenya. Between 1973-1984, trees in forests and woodlands disappeared rapidly from a cover of 152-64 sq. km, i.e. 45-19% of total catchment. The most rapid decrease occurred between 1973-1976 which was associated with immigration into the area in the 1960s and 1970s. Indeed the annual population growth rate in the area was 5.7%. Further most of the population concentrated in the upper and middle catchment areas of Ndunduri, Ngorika, and Nyaituga where the soils and climate were best for commercial crop and livestock farming. This high concentration of people in 1 area along with the high population growth rate contributed greatly to deforestation. In fact, it resulted in a 57.9% loss of total forest and woodland areas. These trees used to cover most of the Ndunduri and Ngorika areas. Agroecosystems have replaced the Juniperus procera and Olea africana forest belts which dominated the Ngorika plains in the past. Further, in 1988, field observations revealed that very limited forest and woodland areas have remained undisturbed. Based on these results and the fact that little substantial efforts towards conservation and afforestation, the researchers predicted that most of the watershed would be with forests and woodlands by 2000. They further noted that deforestation could cause lower water levels in Lake Elementeita, especially during droughts, and worsen soil erosion. Therefore the government should initiate environmental controls in this watershed that match local conditions and the true and increasing needs of the rural population.

  8. Forest dynamics

    PubMed Central

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  9. Forest dynamics.

    PubMed

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  10. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 5, Uncertainty and sensitivity analyses of gas and brine migration for undisturbed performance

    SciTech Connect

    Not Available

    1993-08-01

    Before disposing of transuranic radioactive waste in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments (PAs) of the WIPP for the DOE to provide interim guidance while preparing for a final compliance evaluation. This volume of the 1992 PA contains results of uncertainty and sensitivity analyses with respect to migration of gas and brine from the undisturbed repository. Additional information about the 1992 PA is provided in other volumes. Volume 1 contains an overview of WIPP PA and results of a preliminary comparison with 40 CFR 191, Subpart B. Volume 2 describes the technical basis for the performance assessment, including descriptions of the linked computational models used in the Monte Carlo analyses. Volume 3 contains the reference data base and values for input parameters used in consequence and probability modeling. Volume 4 contains uncertainty and sensitivity analyses with respect to the EPA`s Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Finally, guidance derived from the entire 1992 PA is presented in Volume 6. Results of the 1992 uncertainty and sensitivity analyses indicate that, conditional on the modeling assumptions and the assigned parameter-value distributions, the most important parameters for which uncertainty has the potential to affect gas and brine migration from the undisturbed repository are: initial liquid saturation in the waste, anhydrite permeability, biodegradation-reaction stoichiometry, gas-generation rates for both corrosion and biodegradation under inundated conditions, and the permeability of the long-term shaft seal.

  11. Overall view of tower and adjacent aircraft shelters on flight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view of tower and adjacent aircraft shelters on flight line. View to east. - Plattsburgh Air Force Base, Security Guard Tower, Florida Street at Aircraft Shelters Area, Plattsburgh, Clinton County, NY

  12. Interior building details of Building A, dungeon cell adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon cell adjacent to northwest cell: granite and brick threshold, poured concrete floors, plastered finished walls, vaulted veiling; northwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  13. 10. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  14. Lock 4 View east of lock wall and adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  15. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  16. 1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  17. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  18. View from water showing south facade and adjacent boat slips ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from water showing south facade and adjacent boat slips (Facility Nos. S375 & S376) - U.S. Naval Base, Pearl Harbor, Boat House, Hornet Avenue at Independence Street, Pearl City, Honolulu County, HI

  19. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty.

    PubMed

    Park, Jae Hoo; Kim, Hyeun Sung; Kim, Seok Won

    2016-06-01

    Percutaneous vertebroplasty (PV) is a minimally invasive procedure for osteoporotic vertebral compression fractures that fail to respond to conventional conservative treatment. It significantly improves intolerable back pain within hours, and has a low complication rate. Although rare, PV is not free of complications, most of which are directly related to cement leakage. Because of its association with new adjacent fracture, the importance of cement leakage into the adjacent disc space is paramount. Here, we report an interesting case of cement leakage into the adjacent upper vertebral body as well as disc space following PV. To the best of our knowledge, there has been no report of cement leakage into the adjacent vertebral body following PV. This rare case is presented along with a review of the literature.

  20. 15. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View north from the adjacent B & O railroad bridge of Pier No. 5 and portion of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  1. 7. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View north from the adjacent B & O railroad bridge of Pier No. 1 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  2. 8. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View north from the adjacent B & O railroad bridge of Pier No. 2 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  3. VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT TO BUILDING 199 (POLICE STATION) - U.S. Naval Base, Pearl Harbor, Post Office, Avenue A near Eleventh Avenue, Pearl City, Honolulu County, HI

  4. Basement, room 23, looking southwest into two adjacent offices with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Basement, room 23, looking southwest into two adjacent offices with soundproof walls and pedestal flooring - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  5. 3. View of north side of house facing from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of north side of house facing from adjacent vacant property. Original wood lap siding and trim is covered by aluminum siding. Recessed side porch is in middle. - 645 South Eighteenth Street (House), Louisville, Jefferson County, KY

  6. View of viaduct, looking SE from roof of adjacent parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  7. 1. Ninth Street (west) facade. Adjacent on the north is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Ninth Street (west) facade. Adjacent on the north is the 9th Street facade of 816 E Street. Both buildings were originally one property. - Riley Building, Rendezvous Adult Magazines & Films, 437 Ninth Street, Northwest, Washington, District of Columbia, DC

  8. 6. Detail, vertical guides adjacent to east portal of Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail, vertical guides adjacent to east portal of Tunnel 28, view to southwest, 135mm lens with electronic flash fill. - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

  9. VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  10. 73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, LOOKING WEST BY NORTHWEST, SHOWING EASTERNMOST ARCH OF FORMER GREAT HALL NORTH ARCADE - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  11. Detail exterior view looking north showing piping system adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail exterior view looking north showing piping system adjacent to engine house. Gas cooling system is on far right. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

  12. 52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  13. OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY 391 IN THE FOREGROUND. - U.S. Naval Base, Pearl Harbor, Joint Intelligence Center, Makalapa Drive in Makalapa Administration Area, Pearl City, Honolulu County, HI

  14. Brick incinerator structure located adjacent to "motor courts." This example ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Brick incinerator structure located adjacent to "motor courts." This example is located between Buildings 26 and 27. Facing northeast - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  15. 7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH (NOT IN STUDY AREA) - Orange & Union Streets Neighborhood Study, 8-31 Orange Street, 9-21 Union Street & Stone Alley, Nantucket, Nantucket County, MA

  16. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  17. 72. View of reservoir adjacent to south wall of blowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. View of reservoir adjacent to south wall of blowing engine house where water from furnaces was allowed to cool. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  18. Variation in mangrove forest structure and sediment characteristics in Bocas del Toro, Panama

    USGS Publications Warehouse

    Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Thompson, R.

    2005-01-01

    Mangrove forest structure and sediment characteristics were examined in the extensive mangroves of Bocas del Toro, Republic of Panama. Forest structure was characterized to determine if spatial vegetation patterns were repeated over the Bocas del Toro landscape. Using a series of permanent plots and transects we found that the forests of Bocas del Toro were dominated by Rhizophora mangle with very few individuals of Avicennia germinans and Laguncularia racemosa. Despite this low species diversity, there was large variation in forest structure and in edaphic conditions (salinity, concentration of available phosphorus, Eh and sulphide concentration). Aboveground biomass varied 20-fold, from 6.8 Mg ha-1 in dwarf forests to 194.3 Mg ha-1 in the forests fringing the land. But variation in forest structure was predictable across the intertidal zone. There was a strong tree height gradient from seaward fringe (mean tree height 3.9 m), decreasing in stature in the interior dwarf forests (mean tree height 0.7 m), and increasing in stature in forests adjacent to the terrestrial forest (mean tree height 4.1 m). The predictable variation in forest structure emerges due to the complex interactions among edaphic and plant factors. Identifying predictable patterns in forest structure will aid in scaling up the ecosystem services provided by mangrove forests in coastal landscapes. Copyright 2005 College of Arts and Sciences.

  19. Metal content of biopsies adjacent to dental cast alloys.

    PubMed

    Garhammer, Pauline; Schmalz, G; Hiller, K-A; Reitinger, T

    2003-06-01

    Single case reports indicate that components of dental alloys accumulate in the adjacent soft tissue of the oral cavity. However, data on a wider range of dental alloys and patient groups are scarce. Therefore, the aim of the present study was to examine the metal content of oral tissues adjacent to dental alloys showing persisting signs of inflammation or other discoloration (affected sites) and of healthy control sites with no adjacent metal restoration in 28 patients. The composition of the adjacent alloys was analyzed and compared to the alloy components in the affected sites. Tissue analysis was performed using atomic absorption spectroscopy. Alloy analysis was performed with energy-dispersive X-ray analysis. In the affected sites, the metals Ag, Au, Cu, and Pd prevailed compared to control sites, reflecting the frequency distribution of single metals in the adjacent alloys. In most cases (84%), at least one of the analyzed metals was a component of the alloy and also detected in the tissue. Metal components from almost all dental cast alloys can be detected in adjacent tissue.

  20. Cryptic Methane Emissions from Upland Forest Ecosystems

    SciTech Connect

    Megonigal, Patrick; Pitz, Scott

    2016-04-19

    This exploratory research on Cryptic Methane Emissions from Upland Forest Ecosystems was motivated by evidence that upland ecosystems emit 36% as much methane to the atmosphere as global wetlands, yet we knew almost nothing about this source. The long-term objective was to refine Earth system models by quantifying methane emissions from upland forests, and elucidate the biogeochemical processes that govern upland methane emissions. The immediate objectives of the grant were to: (i) test the emerging paradigm that upland trees unexpectedly transpire methane, (ii) test the basic biogeochemical assumptions of an existing global model of upland methane emissions, and (iii) develop the suite of biogeochemical approaches that will be needed to advance research on upland methane emissions. We instrumented a temperate forest system in order to explore the processes that govern upland methane emissions. We demonstrated that methane is emitted from the stems of dominant tree species in temperate upland forests. Tree emissions occurred throughout the growing season, while soils adjacent to the trees consumed methane simultaneously, challenging the concept that forests are uniform sinks of methane. High frequency measurements revealed diurnal cycling in the rate of methane emissions, pointing to soils as the methane source and transpiration as the most likely pathway for methane transport. We propose the forests are smaller methane sinks than previously estimated due to stem emissions. Stem emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration, resolving differences between models and measurements. The methods we used can be effectively implemented in order to determine if the phenomenon is widespread.

  1. Influence of Anthropogenic Disturbances on Stand Structural Complexity in Andean Temperate Forests: Implications for Managing Key Habitat for Biodiversity.

    PubMed

    Caviedes, Julián; Ibarra, José Tomás

    2017-01-01

    Forest attributes and their abundances define the stand structural complexity available as habitat for faunal biodiversity; however, intensive anthropogenic disturbances have the potential to degrade and simplify forest stands. In this paper we develop an index of stand structural complexity and show how anthropogenic disturbances, namely fire, logging, livestock, and their combined presence, affect stand structural complexity in a southern Global Biodiversity Hotspot. From 2011 to 2013, we measured forest structural attributes as well as the presence of anthropogenic disturbances in 505 plots in the Andean zone of the La Araucanía Region, Chile. In each plot, understory density, coarse woody debris, number of snags, tree diameter at breast height, and litter depth were measured, along with signs of the presence of anthropogenic disturbances. Ninety-five percent of the plots showed signs of anthropogenic disturbance (N = 475), with the combined presence of fire, logging, and livestock being the most common disturbance (N = 222; 44% of plots). The lowest values for the index were measured in plots combining fire, logging, and livestock. Undisturbed plots and plots with the presence of relatively old fires (> 70 years) showed the highest values for the index of stand structural complexity. Our results suggest that secondary forests < 70-year post-fire event, with the presence of habitat legacies (e.g. snags and CWD), can reach a structural complexity as high as undisturbed plots. Temperate forests should be managed to retain structural attributes, including understory density (7.2 ± 2.5 # contacts), volume of CWD (22.4 ± 25.8 m3/ha), snag density (94.4 ± 71.0 stems/ha), stand basal area (61.2 ± 31.4 m2/ha), and litter depth (7.5 ± 2.7 cm). Achieving these values will increase forest structural complexity, likely benefiting a range of faunal species in South American temperate forests.

  2. Influence of Anthropogenic Disturbances on Stand Structural Complexity in Andean Temperate Forests: Implications for Managing Key Habitat for Biodiversity

    PubMed Central

    2017-01-01

    Forest attributes and their abundances define the stand structural complexity available as habitat for faunal biodiversity; however, intensive anthropogenic disturbances have the potential to degrade and simplify forest stands. In this paper we develop an index of stand structural complexity and show how anthropogenic disturbances, namely fire, logging, livestock, and their combined presence, affect stand structural complexity in a southern Global Biodiversity Hotspot. From 2011 to 2013, we measured forest structural attributes as well as the presence of anthropogenic disturbances in 505 plots in the Andean zone of the La Araucanía Region, Chile. In each plot, understory density, coarse woody debris, number of snags, tree diameter at breast height, and litter depth were measured, along with signs of the presence of anthropogenic disturbances. Ninety-five percent of the plots showed signs of anthropogenic disturbance (N = 475), with the combined presence of fire, logging, and livestock being the most common disturbance (N = 222; 44% of plots). The lowest values for the index were measured in plots combining fire, logging, and livestock. Undisturbed plots and plots with the presence of relatively old fires (> 70 years) showed the highest values for the index of stand structural complexity. Our results suggest that secondary forests < 70-year post-fire event, with the presence of habitat legacies (e.g. snags and CWD), can reach a structural complexity as high as undisturbed plots. Temperate forests should be managed to retain structural attributes, including understory density (7.2 ± 2.5 # contacts), volume of CWD (22.4 ± 25.8 m3/ha), snag density (94.4 ± 71.0 stems/ha), stand basal area (61.2 ± 31.4 m2/ha), and litter depth (7.5 ± 2.7 cm). Achieving these values will increase forest structural complexity, likely benefiting a range of faunal species in South American temperate forests. PMID:28068349

  3. The importance of floodplain forests in the conservation and management of neotropical migratory birds in the Midwest

    USGS Publications Warehouse

    Knutson, M.G.; Hoover, J.P.; Klaas, E.E.; Thompson, Frank R.

    1996-01-01

    Bottomland forests of the Central Forest Region of the Upper Midwest are found primarily on the floodplains of large rivers and include at least six types of forest communities. Birds breeding in bottomland forests are affected by extensive variation in latitude, climate, hydrology, forest succession, and change caused by anthropogenic disturbances. The floodplain forest bird community differs in species composition and in relative abundance from adjacent upland habitats. High abundances of some species are found in the floodplain and some species, such as the prothonotary warbler, brown creeper, yellow-billed cuckoo, yellow-bellied sapsucker, and great crested flycatcher, show a clear preference for floodplain forests. Studies of nesting success indicate that, for some species, nest success may be higher in the floodplain than in the uplands. Floodplain birds face threats due to large-scale loss of floodplain forest habitat. Conservation efforts should focus on restoring degraded floodplains by maintaining high tree species diversity and wide corridors. To accomplish this, the underlying hydrodynamics which support a diverse floodplain forest habitat may need to be restored. Large, contiguous tracts of floodplain and upland forests should be maintained where they exist and restored in other locations. This will provide some high quality habitat for area-sensitive neotropical migratory birds (NTMBs) in agricultural landscapes where small, scattered forest fragments are the rule. Future research efforts should examine the importance of floodplain forests in maintaining populations of neotropical migrants, especially birds experiencing population declines in adjacent uplands.

  4. Carbon monoxide uptake by temperate forest soils: the effects of leaves and humus layers

    NASA Astrophysics Data System (ADS)

    Sanhueza, E.; Dong, Y.; Scharffe, D.; Lobert, J. M.; Crutzen, P. J.

    1998-02-01

    Carbon monoxide (CO) fluxes between soil and atmosphere were measured between October 1990 and December 1991 in a temperate, deciduous forest near Darmstadt, Germany. Flux measurements were made with an enclosed chamber technique before and after the removal of leaves and humus from the forest floor as well as from leaves and humus alone. CO depth profiles were obtained during the period July to December, 1991. A net uptake of CO was observed under all conditions with an average of -47.3±24.0ng CO m-2s-1for undisturbed forest soils, which increased significantly when the leaves or both leaves and humus were removed from the forest floor. The mean deposition velocity in undisturbed conditions was 0.027±0.008cm s-1. Our results indicate that CO has a short lifetime within the soil and that the consumption of atmospheric CO occurs mainly in the top few centimeters of the humus layer (O horizon). We conclude that temperate forests are a significant net sink for atmospheric CO and that leaves and humus significantly affect CO fluxes. The global soil sink for atmospheric CO was estimated to be 115 230 Tg CO yr-1.

  5. Climatic impact of tropical lowland deforestation on nearby montane cloud forests.

    PubMed

    Lawton, R O; Nair, U S; Pielke Sr, R A; Welch, R M

    2001-10-19

    Tropical montane cloud forests (TMCFs) depend on predictable, frequent, and prolonged immersion in cloud. Clearing upwind lowland forest alters surface energy budgets in ways that influence dry season cloud fields and thus the TMCF environment. Landsat and Geostationary Operational Environmental Satellite imagery show that deforested areas of Costa Rica's Caribbean lowlands remain relatively cloud-free when forested regions have well-developed dry season cumulus cloud fields. Further, regional atmospheric simulations show that cloud base heights are higher over pasture than over tropical forest areas under reasonable dry season conditions. These results suggest that land use in tropical lowlands has serious impacts on ecosystems in adjacent mountains.

  6. Temperate Forest Methane Sink Diminished by Tree Emissions

    NASA Astrophysics Data System (ADS)

    Megonigal, P.; Pitz, S.

    2015-12-01

    Global budgets ascribe 4-10% of atmospheric CH4 sinks to upland soils and assume that soils are the sole surface for CH4 exchange between upland forests and the atmosphere. The prevailing dogma that upland forests are sinks of atmospheric CH4 was challenged a decade ago by large discrepancies in bottom-up versus top-down models of CH4 concentrations over upland forests that are still unexplained. Evidence of a novel abiotic mechanism for CH4 production from plant tissue is too small to explain the discrepancy. Alternative hypotheses for this observation have been proposed, but not tested. Here we demonstrate that CH4 is emitted from the stems of dominant tree species in an upland forest. Tree emissions occur throughout the growing season while soils adjacent to the trees are consuming CH4, challenging the concept that forests are uniform sinks of CH4. Scaling by stem surface area showed the forest to be a net CH4 source during a wet sample in June and a reduced CH4 sink by 5% annually. High frequency measurements revealed diurnal cycling in the rate of CH4 emissions, pointing to soils as the CH4 source and transpiration as the most likely pathway for CH4 transport. We propose the forests are smaller CH4 sinks than previously estimated due to stem emissions. Stem emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration, resolving differences between models and measurements.

  7. Prioritizing bottomland hardwood forest sites for protection and augmentation

    USGS Publications Warehouse

    Carter, J.; Biagas, J.

    2007-01-01

    Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these restoration efforts has focused on developing tools that can be used for both assessments at the landscape level and policy implementation at the local level. The distribution of bottomland hardwood forests in the Cache and White River watersheds in eastern Arkansas were examined using existing GIS databases. Criteria were developed to select areas that should be conserved or augmented for wildlife habitat. Over 67% of the study area was classified as agriculture, with bottomland hardwood forest the next largest habitat class. The thickness of a forest fragment was defined as the radius of the largest circle that can be inscribed in a fragment. Thickness was used in three ways. First, individual forest fragments were identified and selected based on ecological function using criteria we established. Second, individual fragments that were too small to support interior species, but large enough that if moderately augmented they could recover that function, were identified and selected. These augmentable fragments were further prioritized by adjacency to habitat that might be suitable for reforestation, namely agriculture. Third, watersheds were prioritized for conservation and augmentation based on the size and distributions of forest fragment thickness and area within each watershed.

  8. Habitat use by Swainson's Warblers in a managed bottomland forest

    USGS Publications Warehouse

    Somershoe, S.G.; Hudman, S.P.; Chandler, C.R.

    2003-01-01

    The Swainson's Warbler (Limnothlypis swainsonii) is a locally distributed and relatively uncommon Neotropical migrant songbird that breeds in the bottomland forests of the southeastern United States and spends the nonbreeding season in the Caribbean Basin. Populations of Swainson's Warblers have declined during recent decades as bottomland forests have come under increasingly intensive management and large areas have been converted to other land uses. We examined the habitat around song perches used by male Swainson's Warblers at Big Hammock Wildlife Management Area, a managed bottomland forest along the Altamaha River in Tattnall County, Georgia. We quantified 20 features of habitat structure in areas occupied by Swainson's Warblers (occupied plots) and two sets of controls: unoccupied plots adjacent to occupied plots (adjacent control plots) and unoccupied plots throughout the management area (general control plots). Occupied plots and adjacent control plots both differed in structure from the general control plots. We detected no significant differences, however, in vegetation structure between occupied plots and adjacent control plots. General control plots tended to have a greater number of trees, greater basal area, and a complete canopy, whereas occupied and adjacent control plots had high densities of small stems, cane, herbaceous ground cover, and leaf litter; this latter pattern is typical of documented Swainson's Warbler breeding habitat. Lack of significant differences in vegetation structure may be due to great variation in habitat structure around song perches, small sample size, or scarcity of Swainson's Warblers. Future research should focus on quantifying habitat characteristics around nest sites, song perches, and feeding areas. Our results suggest that management of bottomland habitats by thinning forests and encouraging regeneration of canebrakes is needed for successful conservation of Swainson's Warblers.

  9. Effects of valley meteorology on forest pesticide spraying

    SciTech Connect

    Whiteman, C.D.

    1990-04-01

    Pacific Northwest Laboratory conducted this study for the Missoula Technology and Development Center of the US Department of Agriculture's Forest Service. The purpose of the study was to summarize recent research on valley meteorology during the morning transition period and to qualitatively evaluate the effects of the evolution of valley temperature inversions and wind systems on the aerial spraying of pesticides in National Forest areas of the western United States. Aerial spraying of pesticides and herbicides in forests of the western United States is usually accomplished in the morning hour after first light, during the period known to meteorologists as the morning transition period.'' This document describes the key physical processes that occur during the morning transition period on undisturbed days and the qualitative effects of these processes on the conduct of aerial spraying operations. Since the timing of valley meteorological events may be strongly influenced by conditions that are external to the valley, such as strong upper-level winds or the influence of clouds on the receipt of solar energy in the valley, some remarks are made on the qualitative influence of these processes. Section 4 of this report suggests ways to quantify some of the physical processes to provide useful guidance for the planning and conduct of spraying operations. 12 refs., 9 figs.

  10. Late glacial and early Holocene Landscapes in northern New England and adjacent areas of Canada

    NASA Astrophysics Data System (ADS)

    Davis, R. B.; Jacobson, G. L.

    1985-05-01

    The landscapes of northern New England and adjacent areas of Canada changed greatly between 14,000 and 9000 yr B.P.: deglaciation occurred, sea levels and shorelines shifted, and a vegetational transition from tundra to closed forest took place. Data from 51 14C-dated sites from a range of elevations were used to map ice and sea positions, physiognomic vegetational zones, and the spread of individual tree taxa in the region. A continuum of tundra-woodland-forest passed northeastward and northward without major hesitation or reversal. An increased rate of progression from 11,000 to 10,000 yr B.P. suggests a more rapid warming than in the prior 2000-3000 yr. Elevational gradients controlled the patterns of deglaciation and vegetational change. The earliest spread of tree taxa was via the lowlands of southern Vermont and New Hampshire, and along a coastal corridor in Maine. Only after 12,000 yr B.P. did the taxa spread northward through the rest of the area. Different tree species entered the southern part of the area at different times and continued their spread at different rates. The approximate order of arrival follows: poplars (13,000-12,000 yr B.P. in the south), spruces, paper birch, and jack pine, followed by balsam fir and larch, and possibly ironwood, ash, and elm, and somewhat later by oak, maple, white pine, and finally hemlock (10,000-9000 yr B.P. in the south).

  11. Characterizing Structure, Microclimate and Decomposition of Peatland, Beachfront, and Newly Logged Forest Edges in Southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Concannon, Julie Ann

    In this study, I examined the forest structure, composition, microclimate, and decomposition of three common edge types in southeastern Alaska including; peatland, beachfront, and new clearcuts adjacent to productive western hemlock-Sitka spruce forests. Sites were located on 4 larger islands of the Alexander Archipelago in southeastern Alaska. The study was focussed on transects extending from the open area, through the forest boundary to 200 m into the forest. Twenty-two edges were examined during 1990 and 1991. Forest structure was unique for each edge type. Peatland -forest edges exhibit feathered transition of short and sparse tree growth to large dense old-growth western hemlock -Sitka spruce forests. Beachfront-forest edges were sealed at the boundary by a multi-layering of shrubs, small trees, mid-canopy trees, and some emergents. The transition to large productive old-growth was abrupt. Clearcut-forest edges were essentially old-growth forests opened up by logging. Average size of trees at the boundary was large but stand size and productivity decreased moving into the forest. Productive western hemlock-Sitka spruce associations were not apparent for a long distance into the forest. Herbaceous cover appeared to be directly linked to light levels along the forest transects. Because structure was so inherently different for each edge type, microclimatic gradients from open area to the forest interior environment varied with edge type. The strongest gradients were observed on sunny and extremely windy days. An edge index value (EIV) was calculated to differentiate edge-affected microclimate from interior environments. Edge type influenced forest microclimate such that; (1) Peatlands affected interior radiation and air temperature range for 120 m into the forest until interior environments were encountered. (2) Beachfront-forests were penetrated by ocean winds for up to 120 m however, other variables such as interior air temperature and relative humidity were

  12. The process-based stand growth model Formix 3-Q applied in a GIS environment for growth and yield analysis in a tropical rain forest.

    PubMed

    Ditzer, T.; Glauner, R.; Förster, M.; Köhler, P.; Huth, A.

    2000-03-01

    Managing tropical rain forests is difficult because few long-term field data on forest growth and the impact of harvesting disturbance are available. Growth models may provide a valuable tool for managers of tropical forests, particularly if applied to the extended forest areas of up to 100,000 ha that typically constitute the so-called forest management units (FMUs). We used a stand growth model in a geographic information system (GIS) environment to simulate tropical rain forest growth at the FMU level. We applied the process-based rain forest growth model Formix 3-Q to the 55,000 ha Deramakot Forest Reserve (DFR) in Sabah, Malaysia. The FMU was considered to be composed of single and independent small-scale stands differing in site conditions and forest structure. Field data, which were analyzed with a GIS, comprised a terrestrial forest inventory, site and soil analyses (water, nutrients, slope), the interpretation of aerial photographs of the present vegetation and topographic maps. Different stand types were determined based on a classification of site quality (three classes), slopes (four classes), and present forest structure (four strata). The effects of site quality on tree allometry (height-diameter curve, biomass allometry, leaf area) and growth (increment size) are incorporated into Formix 3-Q. We derived allometric relations and growth factors for different site conditions from the field data. Climax forest structure at the stand level was shown to depend strongly on site conditions. Simulated successional pattern and climax structure were compared with field observations. Based on the current management plan for the DFR, harvesting scenarios were simulated for stands on different sites. The effects of harvesting guidelines on forest structure and the implications for sustainable forest management at Deramakot were analyzed. Based on the stand types and GIS analysis, we also simulated undisturbed regeneration of the logged-over forest in the DFR at

  13. Biomechanical effects of pedicle screw fixation on adjacent segments.

    PubMed

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p < 0.05), and the maximal torque in the fusion model was about threefold (p < 0.05) that in the control model. And in axial rotation, the ROM of cranial and caudal adjacent segments was increased by about 100 % (p < 0.001), and the maximal torque was about sixfold (p < 0.01) that in the control model. The ROM of adjacent segments was significantly increased after pedicle screw fixation as assessed by biomechanical tests regulated by an angular displacement load, but not in those regulated by torque. We present the results of biomechanical tests regulated by torque and angular displacement and show that the maximum torque of the fusion model was larger than that of the control model in the biomechanical test regulated by an angular displacement load, suggesting that mechanical stress on the segments adjacent to the fused segment is large. We think that ASD arises after spinal fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically

  14. Education Highlights: Forest Biomass

    ScienceCinema

    Barone, Rachel; Canter, Christina

    2016-07-12

    Argonne intern Rachel Barone from Ithaca College worked with Argonne mentor Christina Canter in studying forest biomass. This research will help scientists develop large scale use of biofuels from forest biomass.

  15. Education Highlights: Forest Biomass

    SciTech Connect

    Barone, Rachel; Canter, Christina

    2016-01-27

    Argonne intern Rachel Barone from Ithaca College worked with Argonne mentor Christina Canter in studying forest biomass. This research will help scientists develop large scale use of biofuels from forest biomass.

  16. The influece of forest gaps on some properties of humus in a managed beech forest, northern Iran

    NASA Astrophysics Data System (ADS)

    Vajari, K. A.

    2015-10-01

    The present research focuses on the effect of eight-year-old artificially created gaps on some properties of humus in managed beech-dominated stand in Hyrcanian forest of northern Iran. In this study, six-teen gaps were sampled in site and were classified into four classes (small, medium, large, and very large) with four replications for each. Humus sampling was carried out at the centre and at the cardinal points within each gap as well as in the adjacent closed stand, separately, as composite samples. The variables of organic carbon, P, K, pH, and total N were measured for each sample. It was found that the gap size had significant effect only on total N (%) and organic carbon (%) in beech stand. The amount of potassium clearly differed among three positions in beech forest. The adjacent stand had higher significantly potassium than center and edge of gaps. Different amount of potassium was detected in gap center and gap edge. Comparison of humus properties between gaps and its adjacent stand pointed to the higher amount of potassium in adjacent stand than that in gaps but there was no difference between them regarding other humus properties. According to the results, it can be concluded that there is relatively similar condition among gaps and closed adjacent stands in terms of humus properties eight years after logging in the beech stand.

  17. Towards Restoration of Missing Underwater Forests

    PubMed Central

    Vergés, Adriana; Coleman, Melinda A.; Steinberg, Peter D.

    2014-01-01

    Degradation of natural habitats due to urbanization is a major cause of biodiversity loss. Anthropogenic impacts can drive phase shifts from productive, complex ecosystems to less desirable, less diverse systems that provide fewer services. Macroalgae are the dominant habitat-forming organisms on temperate coastlines, providing habitat and food to entire communities. In recent decades, there has been a decline in macroalgal cover along some urbanised shorelines, leading to a shift from diverse algal forests to more simple turf algae or barren habitats. Phyllospora comosa, a major habitat forming macroalga in south-eastern Australia, has disappeared from the urban shores of Sydney. Its disappearance is coincident with heavy sewage outfall discharges along the metropolitan coast during 1970s and 1980s. Despite significant improvements in water-quality since that time, Phyllospora has not re-established. We experimentally transplanted adult Phyllospora into two rocky reefs in the Sydney metropolitan region to examine the model that Sydney is now suitable for the survival and recruitment of Phyllospora and thus assess the possibility of restoring Phyllospora back onto reefs where it was once abundant. Survival of transplanted individuals was high overall, but also spatially variable: at one site most individuals were grazed, while at the other site survival was similar to undisturbed algae and procedural controls. Transplanted algae reproduced and recruitment rates were higher than in natural populations at one experimental site, with high survival of new recruits after almost 18 months. Low supply and settlement success of propagules in the absence of adults and herbivory (in some places) emerge as three potential processes that may have been preventing natural re-establishment of this alga. Understanding of the processes and interactions that shape this system are necessary to provide ecologically sensible goals and the information needed to successfully restore

  18. Sources and interpretation of channel complexity in forested subalpine streams of the Southern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Livers, Bridget; Wohl, Ellen

    2016-05-01

    We evaluate correlations between stream geomorphic complexity and characteristics of the adjacent riparian forest, valley geometry, and land use history in forested subalpine streams of the Colorado Front Range. Measures of geomorphic complexity focus on cross-sectional, planform, and instream wood piece and logjam variables. We categorize adjacent riparian forests as old-growth unmanaged forest (OU), younger unmanaged forest (YU), and younger managed forest (YM), and valley geometry as laterally confined, partly confined, or unconfined. Significant differences in geomorphic stream complexity between OU, YU, and YM result primarily from differences in wood pieces and logjams, and these differences correlate strongly with pool volume and organic matter storage. Significant differences in planform and cross-sectional complexity correlate more strongly with valley geometry, but do not explain as much of the observed variability in complexity between streams as do the wood variables. Unconfined OU streams have the largest wood loads and the greatest complexity, whereas legacy effects of logging, tie-drives, and channel simplification create lower complexity in YM streams, even relative to YU streams flowing through similarly aged forest. We find that management history of riparian forests exerts the strongest control on reduced functional stream channel complexity, regardless of riparian forest stand age.

  19. Impacts of changes in land use and fragmentation patterns on Atlantic coastal forests in northern Spain.

    PubMed

    Teixido, Alberto L; Quintanilla, Luis G; Carreño, Francisco; Gutiérrez, David

    2010-01-01

    Changes in forested landscapes may have important consequences for ecosystem services and biodiversity conservation. In northern Spain, major changes in land use occurred during the second half of the 20th century, but their impacts on forests have not been quantified. We evaluated the dynamics of landscape and forest distribution patterns between 1957 and 2003 in Fragas do Eume Natural Park (northwestern Spain). We used orthoimages and a set of standard landscape metrics to determine transitions between land cover classes and to examine forest distribution patterns. Eucalypt plantations showed the greatest increase in area (197%) over time. Furthermore, transitions to eucalypt plantations were found in all major land cover classes. Forest showed a net decline of 20% in total area and represented 30% of the landscape area in 2003. Forest losses were mainly due to eucalypt plantations and the building of a water reservoir, while forest gains were due to increases in shrubland, meadows and cultivated fields which had been recolonised. Forest patch size and core area decreased, and edge length increased over time. In turn, increases were obtained in mean distance between forest patches, and in adjacency to eucalypt plantations and to a water reservoir. These results suggest an increase in forest fragmentation from 1957 to 2003, as well as a change in the nature of the habitat surrounding forest patches. This study shows that land use changes, mostly from eucalypt plantation intensification, negatively affected forested habitats, although some regeneration was ongoing through ecological succession from land abandonment.

  20. Fasting and postprandial volumes of the undisturbed colon: normal values and changes in diarrhea-predominant irritable bowel syndrome measured using serial MRI

    PubMed Central

    Pritchard, S E; Marciani, L; Garsed, K C; Hoad, C L; Thongborisute, W; Roberts, E; Gowland, P A; Spiller, R C

    2014-01-01

    Background Previous assessments of colon morphology have relied on tests which were either invasive or used ionizing radiation. We aimed to measure regional volumes of the undisturbed colon in healthy volunteers (HV) and patients with diarrhea-predominant irritable bowel syndrome (IBS-D). Methods 3D regional (ascending, transverse, and descending) colon volumes were measured in fasting abdominal magnetic resonance (MR) images of 75 HVs and 25 IBS-D patients. Thirty-five of the HV and all 25 IBS-D subjects were fed a standard meal and postprandial MRI data obtained over 225 min. Key Results Colonic regions were identified and 3D maps from cecum to sigmoid flexure were defined. Fasted regional volumes showed wide variation in both HVs being (mean ± SD) ascending colon (AC) 203 ± 75 mL, transverse (TC) 198 ± 79 mL, and descending (DC) 160 ± 86 mL with no difference from IBS-D subjects (AC 205 ± 69 mL, TC 232 ± 100 mL, and DC 151 ± 71 mL, respectively). The AC volume expanded by 10% after feeding (p = 0.007) in the 35 HV possibly due to increased ileo-colonic inflow. A later rise in AC volume occurred from t = 90 to t = 240 min as the meal residue entered the cecum. In contrast, IBS-D subjects showed a much reduced postprandial response of the AC (p < 0.0001) and a greater increase in TC volume after 90 min (p = 0.0244) compared to HV. Conclusions & Inferences We have defined a normal range of the regional volumes of the undisturbed colon in fasted and fed states. The AC in IBS-D appeared less able to accommodate postprandial inflow which may account for faster colonic transit. PMID:24131490

  1. Parasitism at the landscape scale: Cowbirds prefer forests

    USGS Publications Warehouse

    Hahn, D.C.; Hatfield, J.S.

    1995-01-01

    Landscape-scale examination of parasitism patterns of Brown-headed Cowbirds (Molothrus ater) revealed heterogeneous parasitism rates across the mosaic of a forest and associated oldfield communities. In a two-year study in Dutchess County, New York, we found a significantly higher parasitism rate in the forest-interior community (n = 301 nests; 17 species) than on the species in the adjacent and nearby old-field and edge (n = 328 nests; 15 species; 32.3% versus 6.5%; p lt 0.0001). Cowbirds invaded a mature 1300-ha forest stand even when their traditional host species were available in adjacent old-field and edge habitats. The forest and old field study areas were located in a 38,000-ha township with 55% forest cover and contained numerous agriculture, dairy, and horse farms that provided favorable habitat for cowbirds, within-forest examination of parasitism patterns revealed four aspects of cowbird parasitism that contrasted with patterns described in other regions; (1) parasitism was concentrated significantly more often on ground and low-nesting (nests ltoreq 1 m) forest species than on medium- and high nesting species (nests gt 1 m; 35. 01 % versus 2993%; p = 0.0393); (2) parasitism was not significantly greater on Neotropical migrant species than on short-distance migrants and residents; (3) the parasitism rate was not higher in nests close to edges; and (4) the parasitism level was low on certain forest species (such as Wood Thrush) that have experienced high parasitism levels in the Midwest. From a management perspective these data suggest that cowbirds exhibit regional differences in host and habitat use; the target host community of a particular cowbird population is unpredictable at the landscape scale; and a landscape scale should be used in designing cowbird studies to accurately assess local population dynamics.

  2. The Children's Rain Forest.

    ERIC Educational Resources Information Center

    Thornton, Carol A.; And Others

    1995-01-01

    Describes a unit on rain forests in which first graders studied about rain forests, built a classroom rain forest, and created a bulletin board. They also graphed rainfall, estimated body water, and estimated the number of newspapers that could be produced from one canopy tree. (MKR)

  3. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Tarrataca, Luís; Nahimov, Nikolay

    2016-10-01

    A quantum particle evolving by Schrödinger's equation contains, from the kinetic energy of the particle, a term in its Hamiltonian proportional to Laplace's operator. In discrete space, this is replaced by the discrete or graph Laplacian, which gives rise to a continuous-time quantum walk. Besides this natural definition, some quantum walk algorithms instead use the adjacency matrix to effect the walk. While this is equivalent to the Laplacian for regular graphs, it is different for non-regular graphs and is thus an inequivalent quantum walk. We algorithmically explore this distinction by analyzing search on the complete bipartite graph with multiple marked vertices, using both the Laplacian and adjacency matrix. The two walks differ qualitatively and quantitatively in their required jumping rate, runtime, sampling of marked vertices, and in what constitutes a natural initial state. Thus the choice of the Laplacian or adjacency matrix to effect the walk has important algorithmic consequences.

  4. Connectivity of overland flow by drainage network expansion in a rain forest catchment

    NASA Astrophysics Data System (ADS)

    Zimmermann, Beate; Zimmermann, Alexander; Turner, Benjamin L.; Francke, Till; Elsenbeer, Helmut

    2014-02-01

    Soils in various places of the Panama Canal Watershed feature a low saturated hydraulic conductivity (Ks) at shallow depth, which promotes overland-flow generation and associated flashy catchment responses. In undisturbed forests of these areas, overland flow is concentrated in flow lines that extend the channel network and provide hydrological connectivity between hillslopes and streams. To understand the dynamics of overland-flow connectivity, as well as the impact of connectivity on catchment response, we studied an undisturbed headwater catchment by monitoring overland-flow occurrence in all flow lines and discharge, suspended sediment, and total phosphorus at the catchment outlet. We find that connectivity is strongly influenced by seasonal variation in antecedent wetness and can develop even under light rainfall conditions. Connectivity increased rapidly as rainfall frequency increased, eventually leading to full connectivity and surficial drainage of entire hillslopes. Connectivity was nonlinearly related to catchment response. However, additional information on factors such as overland-flow volume would be required to constrain relationships between connectivity, stormflow, and the export of suspended sediment and phosphorus. The effort to monitor those factors would be substantial, so we advocate applying the established links between rain event characteristics, drainage network expansion by flow lines, and catchment response for predictive modeling and catchment classification in forests of the Panama Canal Watershed and in similar regions elsewhere.

  5. Carbon cycling and storage in mangrove forests.

    PubMed

    Alongi, Daniel M

    2014-01-01

    Mangroves are ecologically and economically important forests of the tropics. They are highly productive ecosystems with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Although mangroves occupy only 0.5% of the global coastal area, they contribute 10-15% (24 Tg C y(-1)) to coastal sediment carbon storage and export 10-11% of the particulate terrestrial carbon to the ocean. Their disproportionate contribution to carbon sequestration is now perceived as a means for conservation and restoration and a way to help ameliorate greenhouse gas emissions. Of immediate concern are potential carbon losses to deforestation (90-970 Tg C y(-1)) that are greater than these ecosystems' rates of carbon storage. Large reservoirs of dissolved inorganic carbon in deep soils, pumped via subsurface pathways to adjacent waterways, are a large loss of carbon, at a potential rate up to 40% of annual primary production. Patterns of carbon allocation and rates of carbon flux in mangrove forests are nearly identical to those of other tropical forests.

  6. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

  7. Management of adjacent segment disease after cervical spinal fusion.

    PubMed

    Kepler, Christopher K; Hilibrand, Alan S

    2012-01-01

    Adjacent segment disease (ASD) was described after long-term follow-up of patients treated with cervical fusion. The term describes new-onset radiculopathy or myelopathy referable to a motion segment adjacent to previous arthrodesis and often attributed to alterations in the biomechanical environment after fusion. Evidence suggests that ASD affects between 2% and 3% of patients per year. Although prevention of ASD was one major impetus behind the development of motion-sparing surgery, the literature does not yet clearly distinguish a difference in the rate of ASD between fusion and disk replacement. Surgical techniques during index surgery may reduce the rate of ASD.

  8. The Impact of Selective Logging on the Regional Carbon Budget at the Tapajos National Forest: a Modeling Study

    NASA Astrophysics Data System (ADS)

    Huang, M.; Asner, G. P.; Keller, M.; Knapp, D.

    2005-12-01

    Selective logging has been identified as an important form of land use in the Brazilian Amazon region based on studies in Large-scale Biosphere Atmosphere Experiment (LBA) Phase II (Nepstad et al., 1999; Asner et al., 2004). The ground and canopy damage caused by selective logging could have significant ecological, biogeochemical and micrometeorological consequences. Logging creates canopy gaps that affect photosynthetically active radiation (PAR) interception, latent and sensible heat fluxes, water stress and plant productivity. Also, it creates an increased amount of coarse woody debris (CWD), dead leaves and roots, which enlarge the carbon pools for respiration and fire. Furthermore, the biogeochemical processes in the tropical forest including the nutrient cycles and wildlife would also be altered. Unfortunately, previous studies on impacts of selective logging in that region are generally limited in space and/or time. In this study, a high-resolution (30 m by 30 m) version of the Carnegie-Ames-Stanford Approach (CASA) model is applied to quantify the impact of selective logging on the regional carbon budget at the Tapajos National Forest. A unique aspect of this study is to take advantage of recent progress in characterizing explicitly the spatial and temporal dynamics of forest canopy gaps and CWD generation based upon field and remote sensing measurements (Asner et al., 2005; Keller et al., 2004). An undisturbed forest scenario and a logging scenario will be considered. The undisturbed forest scenario corresponds to the condition prior to logging and will serve as a baseline simulation for comparison. By assimilating satellite-derived vegetation indices, gap fractions, and CWD estimates before and after logging, we expect to simulate the spatial changes of carbon storage and carbon release caused by logging over time. Measurements from the km 83 flux tower located at the Tapajos National Forest will be used to constrain the model. This study constitutes our

  9. Identification of sediment sources in forested watersheds with surface coal mining disturbance using carbon and nitrogen isotopes

    SciTech Connect

    Fox, J.F.

    2009-10-15

    Sediments and soils were analyzed using stable carbon and nitrogen isotope ratio mass spectrometry and carbon and nitrogen elemental analyses to evaluate the their ability to indicate land-use and land management disturbance and pinpoint loading from sediment transport sources in forested watersheds disturbed by surface coal mining. Samples of transported sediment particulate organic matter were collected from four watersheds in the Southern Appalachian forest in Kentucky. The four watersheds had different surface coal mining history that were classified as undisturbed, active mining, and reclaimed conditions. Soil samples were analyzed including reclaimed grassland soils, undisturbed forest soils, geogenic organic matter associated with coal fragments in mining spoil, and soil organic matter from un-mined grassland soils. Statistically significant differences were found for all biogeochemical signatures when comparing transported sediments from undisturbed watersheds and surface coal mining disturbed watersheds and the results were attributed to differences in erosion sources and the presence of geogenic organic matter. Sediment transport sources in the surface coal mining watersheds analyzed using Monte Carlo mass balance un-mixing found that: {delta}{sup 15}N showed the ability to differentiate streambank erosion and surface soil erosion; and {delta} {sup 13}C showed the ability to differentiate soil organic matter and geogenic organic matter. This suggests that streambank erosion downstream of surface coal mining sites is a significant source of sediment in coal mining disturbed watersheds. The results suggest that the sediment transport processes governing streambank erosion loads are taking longer to reach geomorphologic equilibrium in the watershed as compared with the surface erosion processes.

  10. Generation of Novel Traj18-Deficient Mice Lacking Vα14 Natural Killer T Cells with an Undisturbed T Cell Receptor α-Chain Repertoire

    PubMed Central

    Dashtsoodol, Nyambayar; Shigeura, Tomokuni; Ozawa, Ritsuko; Harada, Michishige; Kojo, Satoshi; Watanabe, Takashi; Koseki, Haruhiko; Nakayama, Manabu; Ohara, Osamu; Taniguchi, Masaru

    2016-01-01

    Invariant Vα14 natural killer T (NKT) cells, characterized by the expression of a single invariant T cell receptor (TCR) α chain encoded by rearranged Trav11 (Vα14)-Traj18 (Jα18) gene segments in mice, and TRAV10 (Vα24)-TRAJ18 (Jα18) in humans, mediate adjuvant effects to activate various effector cell types in both innate and adaptive immune systems that facilitates the potent antitumor effects. It was recently reported that the Jα18-deficient mouse described by our group in 1997 harbors perturbed TCRα repertoire, which raised concerns regarding the validity of some of the experimental conclusions that have been made using this mouse line. To resolve this concern, we generated a novel Traj18-deficient mouse line by specifically targeting the Traj18 gene segment using Cre-Lox approach. Here we showed the newly generated Traj18-deficient mouse has, apart from the absence of Traj18, an undisturbed TCRα chain repertoire by using next generation sequencing and by detecting normal generation of Vα19Jα33 expressing mucosal associated invariant T cells, whose development was abrogated in the originally described Jα18-KO mice. We also demonstrated here the definitive requirement for NKT cells in the protection against tumors and their potent adjuvant effects on antigen-specific CD8 T cells. PMID:27064277

  11. Forest microsite effects on community composition of ectomycorrhizal fungi on seedlings of Picea abies and Betula pendula.

    PubMed

    Tedersoo, Leho; Suvi, Triin; Jairus, Teele; Kõljalg, Urmas

    2008-05-01

    Niche differentiation in soil horizons, host species and natural nutrient gradients contribute to the high diversity of ectomycorrhizal fungi in boreal forests. This study aims at documenting the diversity and community composition of ectomycorrhizal fungi of Norway spruce (Picea abies) and silver birch (Betula pendula) seedlings in five most abundant microsites in three Estonian old-growth forests. Undisturbed forest floor, windthrow mounds and pits harboured more species than brown- and white-rotted wood. Several species of ectomycorrhizal fungi were differentially represented on either hosts, microsites and sites. Generally, the most frequent species in dead wood were also common in forest floor soil. Ordination analyses suggested that decay type determined the composition of EcM fungal community in dead wood. Root connections with in-growing mature tree roots from below affected the occurrence of certain fungal species on seedling roots systems in dead wood. This study demonstrates that ectomycorrhizal fungi differentially establish in certain forest microsites that is attributable to their dispersal and competitive abilities. Elevated microsites, especially decayed wood, act as seed beds for both ectomycorrhizal forest trees and fungi, thus affecting the succession of boreal forest ecosystems.

  12. El Niño droughts and their effects on tree species composition and diversity in tropical rain forests.

    PubMed

    Slik, J W F

    2004-09-01

    In this study I investigated the effects of the extreme, 1997/98 El Niño related drought on tree mortality and understorey light conditions of logged and unlogged tropical rain forest in the Indonesian province of East Kalimantan (Borneo). My objectives were to test (1) whether drought had a significant effect on tree mortality and understorey light conditions, (2) whether this effect was greater in logged than in undisturbed forest, (3) if the expected change in tree mortality and light conditions had an effect on Macaranga pioneer seedling and sapling densities, and (4) which (a)biotic factors influenced tree mortality during the drought. The 1997/1998 drought led to an additional tree mortality of 11.2, 18.1, and 22.7% in undisturbed, old logged and recently logged forest, respectively. Mortality was highest in logged forests, due to extremely high mortality of pioneer Macaranga trees (65.4%). Canopy openness was significantly higher during the drought than during the non-drought year (6.0, 8.6 and 10.4 vs 3.7, 3.8 and 3.7 in undisturbed, old logged and recently logged forest, respectively) and was positively correlated with the number of dead standing trees. The increase in light in the understorey was accompanied by a 30 to 300-fold increase in pioneer Macaranga seedling densities. Factors affecting tree mortality during drought were (1) tree species successional status, (2) tree size, and (3) tree location with respect to soil moisture. Tree density and basal area per surface unit had no influence on tree mortality during drought. The results of this study show that extreme droughts, such as those associated with El Niño events, can affect the tree species composition and diversity of tropical forests in two ways: (1) by disproportionate mortality of certain tree species groups and tree size classes, and (2) by changing the light environment in the forest understorey, thereby affecting the recruitment and growth conditions of small and immature trees.

  13. Estimating Tropical Forest Structure Using a Terrestrial Lidar

    PubMed Central

    Palace, Michael; Sullivan, Franklin B; Ducey, Mark; Herrick, Christina

    2016-01-01

    Forest structure comprises numerous quantifiable biometric components and characteristics, which include tree geometry and stand architecture. These structural components are important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying biometric properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in a predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, Fast Fourier Transform (FFT), number of layers and plant area index to develop statistical relationships with field data. We developed statistical models using a series of multiple linear regressions, all of which converged on significant relationships with the strongest relationship being for mean crown depth (r2 = 0.88, p < 0.001, RMSE = 1.04 m). Tree density was found to have the poorest significant relationship (r2 = 0.50, p < 0.01, RMSE = 153.28 n ha-1). We found a significant relationship between basal area and lidar metrics (r2 = 0.75, p < 0.001, RMSE = 3.76 number ha-1). Parameters selected in our models varied, thus indicating the potential relevance of multiple features in canopy profiles and geometry that are related to field-measured structure. Models for biomass estimation included structural canopy

  14. Estimating Tropical Forest Structure Using a Terrestrial Lidar.

    PubMed

    Palace, Michael; Sullivan, Franklin B; Ducey, Mark; Herrick, Christina

    2016-01-01

    Forest structure comprises numerous quantifiable biometric components and characteristics, which include tree geometry and stand architecture. These structural components are important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying biometric properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in a predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, Fast Fourier Transform (FFT), number of layers and plant area index to develop statistical relationships with field data. We developed statistical models using a series of multiple linear regressions, all of which converged on significant relationships with the strongest relationship being for mean crown depth (r2 = 0.88, p < 0.001, RMSE = 1.04 m). Tree density was found to have the poorest significant relationship (r2 = 0.50, p < 0.01, RMSE = 153.28 n ha-1). We found a significant relationship between basal area and lidar metrics (r2 = 0.75, p < 0.001, RMSE = 3.76 number ha-1). Parameters selected in our models varied, thus indicating the potential relevance of multiple features in canopy profiles and geometry that are related to field-measured structure. Models for biomass estimation included structural canopy

  15. Forested wetland habitat

    USGS Publications Warehouse

    Duberstein, Jamie A.; Krauss, Ken W.; Kennish, Michael J.

    2015-01-01

    A forested wetland (swamp) is a forest where soils are saturated or flooded for at least a portion of the growing season, and vegetation, dominated by trees, is adapted to tolerate flooded conditions. A tidal freshwater forested wetland is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity of soil porewater less than 0.5 g/l. It is known locally as tidal várzea in the Amazon delta, Brazil. A tidal saltwater forested wetland (mangrove forest) is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity often exceeding 3 g/l and reaching levels that can exceed seawater. Mangrove ecosystems are composed of facultative halophytes that generally experience better growth at moderate salinity concentrations.

  16. The empty forest revisited.

    PubMed

    Wilkie, David S; Bennett, Elizabeth L; Peres, Carlos A; Cunningham, Andrew A

    2011-03-01

    Tropical forests are among the most species-rich ecosystems on the planet. Some authors argue that predictions of a tropical forest extinction crisis based on analyses of deforestation rates are overly pessimistic since they do not take account of future agricultural abandonment as a result of rural-urban migration and subsequent secondary regrowth. Even if such regrowth occurs, it is crucial to consider threats to species that are not directly correlated with area of forest cover. Hunting is an insidious but significant driver of tropical forest defaunation, risking cascading changes in forest plant and animal composition. Ineffective legislation and enforcement along with a failure of decision makers to address the threats of hunting is fanning the fire of a tropical forest extinction crisis. If tropical forest ecosystems are to survive, the threat of unsustainable hunting must be adequately addressed now.

  17. Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

    PubMed

    Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo

    2015-01-01

    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

  18. The value of primary, secondary, and plantation forests for a neotropical herpetofauna.

    PubMed

    Gardner, Toby A; Ribeiro-Júnior, Marco Antônio; Barlow, Jos; Avila-Pires, Teresa Cristina Sauer; Hoogmoed, Marinus S; Peres, Carlos A

    2007-06-01

    Plantation forests and second-growth forests are becoming dominant components of many tropical forest landscapes. Yet there is little information available concerning the consequences of different forestry options for biodiversity conservation in the tropics. We sampled the leaf-litter herpetofauna of primary, secondary, and Eucalyptus plantation forests in the Jari River area of northeastern Brazilian Amazonia. We used four complementary sampling techniques, combined samples from 2 consecutive years, and collected 1739 leaf-litter amphibians (23 species) and 1937 lizards (30 species). We analyzed the data for differences among forest types regarding patterns of alpha and beta diversity, species-abundance distributions, and community structure. Primary rainforest harbored significantly more species, but supported a similar abundance of amphibians and lizards compared with adjacent areas of second-growth forest or plantations. Plantation forests were dominated by wide-ranging habitat generalists. Secondary forest faunas contained a number of species characteristic of primary forest habitat. Amphibian communities in secondary forests and Eucalyptus plantations formed a nested subset of primary forest species, whereas the species composition of the lizard community in plantations was distinct, and was dominated by open-area species. Although plantation forests are relatively impoverished, naturally regenerating forests can help mitigate some negative effects of deforestation for herpetofauna. Nevertheless, secondary forest does not provide a substitute for primary forest, and in the absence of further evidence from older successional stands, we caution against the optimistic claim that natural forest regeneration in abandoned lands will provide refuge for the many species that are currently threatened by deforestation.

  19. Variation in Indigenous Forest Resource Use in Central Guyana

    PubMed Central

    Ozanne, Claire M. P.; Cabral, Christie; Shaw, Peter J.

    2014-01-01

    Sustainable forest conservation strategies should be based on local as well as landscape-scale forest resource use data. Using ecological and sociological techniques, we test the hypotheses that (1) forest resource use differs between ethnic and socioeconomic indigenous groups and (2) that this difference results in differing spatial patterns of resource use, with implications for forest diversity and for conservation planning. In the North Rupununi Guyana, three adjacent indigenous communities (differing in their indigenous/immigrant balance) were recorded using 73 animal and 164 plant species (plus several unidentified ethno-species). Farm sites formed important foci for most forest based activities and ex-farm sites supported similar floristic diversity to surrounding forest. Resource usage differences between communities could be attributed to socio-cultural drivers, e.g. mammal meat consumption and the use of the fruits from the palm tree A. maripa were higher in more traditional households. When extracting household construction timber, lower income groups created small scattered felling sites akin to tree fall gaps whereas higher income groups created larger gaps. Lower income (indigenous) households tended to clear larger but more contained sites for farming while mixed or non-Amerindian household tended to clear smaller but more widely dispersed farm sites. These variations resulted in different patterns of forest disturbance originating from agriculture and timber extraction. PMID:25068801

  20. Biological diversity of created forested wetlands in comparison to reference forested wetlands in the Bay watershed

    USGS Publications Warehouse

    Perry, M.C.; Osenton, P.C.; Stoll, C.S.; Therres, Glenn D.

    2001-01-01

    Amphibians, reptiles, birds, and mammals were surveyed at six created forested wetlands in central Maryland and at six adjacent reference forested wetlands during 1993-1996 to determine comparative biological diversity of these habitats. Amphibians and reptiles were caught in pitfall and funnel traps associated with 15.4m (50 ft) drift fences. Birds were surveyed with a complete count while walking through each area. Mammals were surveyed by capture in live traps. More species and total individuals of amphibians were caught on the reference wetlands than on the created wetlands. The red-backed salamander (Plethodon cinereus), the four-toed salamander (Hemidactylium scutatum), the eastern spadefoot (Scaphiopus holbrooki), and the wood frog (Rana sylvatica) were captured on the reference wetlands, but not on the created sites. The wood frog was captured at all reference sites and may represent the best amphibian species to characterize a forested wetland. Reptiles were not caught in sufficient numbers to warrant comparisons. Ninety-two bird species were recorded on created sites and 55 bird species on the reference sites. Bird species on the created sites represented those typically found in nonforested habitats. Mammal species were similar on both sites, but overall the reference sites had three times the number caught on created sites. The meadow vole (Microtus pennsylvanicus) was the dominant species captured on created sites, and the white-footed mouse (Peromyscus leucopus) was the dominant species on reference sites, with little habitat overlap for these two species. Although species richness and total number of animals were high for created forested wetlands, these survey results show major differences from species expected for a forested wetland. The created forested wetlands appear to provide good habitat for wildlife, but are probably not providing the full functions and values of the forested wetlands that they were constructed to replace.

  1. LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ROOM; THE PIPES AT THE BOTTOM ARE PART OF THE RADIANT HEATING SYSTEM USED FOR HEATING THE FACTORY DURING COLD WEATHER. - Westmoreland Glass Company, Seventh & Kier Streets, Grapeville, Westmoreland County, PA

  2. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  3. 12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE CANAL, LOOKING EAST. BARREN AREA IN FOREGROUND IS DECOMPOSING SAWDUST. DIRT PILE IN BACKGROUND IS THE EDGE OF THE SUMMIT COUNTY LANDFILL. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  4. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  5. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  6. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  7. 11. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  8. 12. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  9. 10. Detail and contextual view of bridge and adjacent farmstead ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  10. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  11. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  12. 8. Exterior view, showing tank and associated piping adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Exterior view, showing tank and associated piping adjacent to Test Cell 6, Systems Integration Laboratory Building (T-28), looking south. - Air Force Plant PJKS, Systems Integration Laboratory, Systems Integration Laboratory Building, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  13. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  14. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  15. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF NEIGHBORHOOD. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  16. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ROAD WITH BIRCH CIRCLE. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  17. 3. View of side of house facing north from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of side of house facing north from adjacent property. Original wood siding and trim is visible. Note: later addition to rear of house is shown in right side of photograph. - 322 South Fifteenth Street (House), Louisville, Jefferson County, KY

  18. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  19. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  20. MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA FACES SOUTHEAST TOWARD NORTH SIDE OF PUMP HOUSE. INL NEGATIVE NO. 2690. Unknown Photographer, 6/1951. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. 1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN BUILDING (BASSIN'S RESTAURANT) (HABS No. DC-357), 501-511 14TH STREET (THE LOCKER ROOM) HABS No. DC-356) ON CORNER, AND MUNSEY BUILDING (HABS No. DC-358) - William J. Stone Building, 1345 E Street Northwest, Washington, District of Columbia, DC

  2. 2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  3. 7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

  4. Changes in Amazonian forest biomass, dynamics, and composition, 1980-2002

    NASA Astrophysics Data System (ADS)

    Phillips, Oliver L.; Higuchi, Niro; Vieira, Simone; Baker, Timothy R.; Chao, Kuo-Jung; Lewis, Simon L.

    Long-term, on-the-ground monitoring of forest plots distributed across Amazonia provides a powerful means to quantify stocks and fluxes of biomass and biodiversity. Here we examine the evidence for concerted changes in the structure, dynamics, and functional composition of old-growth Amazonian forests over recent decades. Mature forests have, as a whole, gained biomass and undergone accelerated growth and dynamics, but questions remain as to the long-term persistence of these changes. Because forest growth on average exceeds mortality, intact Amazonian forests have been functioning as a carbon sink. We estimate a net biomass increase in trees ≥10 cm diameter of 0.62 ± 0.23 t C ha-1 a-1 through the late twentieth century. If representative of the wider forest landscape, this translates into a sink in South American old-growth forest of at least 0.49 ± 0.18 Pg C a-1. If other biomass and necromass components also increased proportionally, the estimated South American old-growth forest sink is 0.79 ± 0.29 Pg C a-1, before allowing for possible gains in soil carbon. If tropical forests elsewhere are behaving similarly, the old-growth biomass forest sink would be 1.60 ± 0.58 Pg C a-1. This bottom-up estimate of the carbon balance of tropical forests is preliminary, pending syntheses of detailed biometric studies across the other tropical continents. There is also some evidence for recent changes in the functional composition (biodiversity) of Amazonian forest, but the evidence is less comprehensive than that for changes in structure and dynamics. The most likely driver(s) of changes are recent increases in the supply of resources such as atmospheric carbon dioxide, which would increase net primary productivity, increasing tree growth and recruitment, and, in turn, mortality. In the future the growth response of remaining undisturbed Amazonian forests is likely to saturate, and there is a risk of these ecosystems transitioning from sink to source driven by higher

  5. Forest Walk Methods for Localizing Body Joints from Single Depth Image

    PubMed Central

    Jung, Ho Yub; Lee, Soochahn; Heo, Yong Seok; Yun, Il Dong

    2015-01-01

    We present multiple random forest methods for human pose estimation from single depth images that can operate in very high frame rate. We introduce four algorithms: random forest walk, greedy forest walk, random forest jumps, and greedy forest jumps. The proposed approaches can accurately infer the 3D positions of body joints without additional information such as temporal prior. A regression forest is trained to estimate the probability distribution to the direction or offset toward the particular joint, relative to the adjacent position. During pose estimation, the new position is chosen from a set of representative directions or offsets. The distribution for next position is found from traversing the regression tree from new position. The continual position sampling through 3D space will eventually produce an expectation of sample positions, which we estimate as the joint position. The experiments show that the accuracy is higher than current state-of-the-art pose estimation methods with additional advantage in computation time. PMID:26402029

  6. Resilience of a thinned Eucalyptus regnans forest to long-term drought

    NASA Astrophysics Data System (ADS)

    Hawthorne, S. N.; Lane, P. N. J.; Benyon, R. G.

    2014-12-01

    The duration and severity of drought has been predicted to increase with climate change. Understanding vegetation response to protracted drought is important to predict their future response and develop adaptive management strategies. We examined the transpiration of Eucalyptus regnans forest at the end of the Millennium Drought, which affected southeast Australia from the mid-1990s to 2009. The forested catchment, Crotty Creek, has been subjected to a strip-thinning treatment in the early 1980s. Measurements of sap flow were conducted using the compensation heat pulse technique over 13 months from December 2009. Transpiration appeared to be energy-limited rather than water-limited, with daily maximum VPD and solar radiation being good predictors of sap flux density. The perennial streamflow and unlimited transpiration at the end of the drought indicate a large soil-water buffer in the system. The post-thinning evapotranspiration (ET) of the catchment was likely to be lower than ET of an undisturbed catchment with similar stand age (70-year old) due to the lower post-thinning basal area. In contrast to this, the streamflow of a dryer, 34-year old mixed eucalypt forest ceased for several months during the same drought. Thus, the resilience of E. regnans forests during a severe drought may depend on the soil-water buffer and stomatal control, while silvicultural treatment may help reduce water stress in dryer and younger forests.

  7. A Linearized k-ɛ Model of Forest Canopies and Clearings

    NASA Astrophysics Data System (ADS)

    Segalini, Antonio; Nakamura, Tetsuya; Fukagata, Koji

    2016-12-01

    A linearized analysis of the Reynolds-averaged Navier-Stokes (RANS) equations is proposed where the k-ɛ turbulence model is used. The flow near the forest is obtained as the superposition of the undisturbed incoming boundary layer plus a velocity perturbation due to the forest presence, similar to the approach proposed by Belcher et al. (J Fluid Mech 488:369-398, 2003). The linearized model has been compared against several non-linear RANS simulations with many leaf-area index values and large-eddy simulations using two different values of leaf-area index. All the simulations have been performed for a homogeneous forest and for four different clearing configurations. Despite the model approximations, the mean velocity and the Reynolds stress overline{u'w'} have been reasonably reproduced by the first-order model, providing insight about how the clearing perturbs the boundary layer over forested areas. However, significant departures from the linear predictions are observed in the turbulent kinetic energy and velocity variances. A second-order correction, which partly accounts for some non-linearities, is therefore proposed to improve the estimate of the turbulent kinetic energy and velocity variances. The results suggest that only a region close to the canopy top is significantly affected by the forest drag and dominated by the non-linearities, while above three canopy heights from the ground only small effects are visible and both the linearized model and the simulations have the same trends there.

  8. Forest Fragmentation as Cause of Bacterial Transmission among Nonhuman Primates, Humans, and Livestock, Uganda

    PubMed Central

    Gillespie, Thomas R.; Rwego, Innocent B.; Estoff, Elizabeth L.; Chapman, Colin A.

    2008-01-01

    We conducted a prospective study of bacterial transmission among humans, nonhuman primates (primates hereafter), and livestock in western Uganda. Humans living near forest fragments harbored Escherichia coli bacteria that were ≈75% more similar to bacteria from primates in those fragments than to bacteria from primates in nearby undisturbed forests. Genetic similarity between human/livestock and primate bacteria increased ≈3-fold as anthropogenic disturbance within forest fragments increased from moderate to high. Bacteria harbored by humans and livestock were approximately twice as similar to those of red-tailed guenons, which habitually enter human settlements to raid crops, than to bacteria of other primate species. Tending livestock, experiencing gastrointestinal symptoms, and residing near a disturbed forest fragment increased genetic similarity between a participant’s bacteria and those of nearby primates. Forest fragmentation, anthropogenic disturbance within fragments, primate ecology, and human behavior all influence bidirectional, interspecific bacterial transmission. Targeted interventions on any of these levels should reduce disease transmission and emergence. PMID:18760003

  9. [Population dynamics of the palm Euterpe oleracea (Arecaceae) from flooded forests in Choco, Colombian Pacific].

    PubMed

    Arango, Diego A; Duque, Alvaro J; Muñoz, Edinson

    2010-03-01

    The palm Euterpe oleracea is a dominant and promising species in flood plains of the Atrato river, Choco region of Colombia. We assessed the population dynamics of this species through growth rates, mortality and recruitment patterns for a period of two and a half years. Dynamic rates were compared among mixed and pure flood plain palm forests. These forests types were associated to different flooding regimes. Trees and palms were thinned in a portion for each forest type, the rest was left undisturbed. We used projection matrices to follow population trends. Thinning increased the transition probability of smaller individuals, but decreased it for larger individuals, as is typical of light demanding species. Thinning also increased mortality rates in almost all size classes, but did not affect recruitment rates. Under natural conditions, the E. oleracea populations are in equilibrium in pure and mixed forests. Thinning increased population growth in both forest types, suggesting the role played by density-dependent processes on the population size of this species.

  10. Use of cotton gin trash to enhance denitrification in restored forested wetlands

    USGS Publications Warehouse

    Ullah, S.; Faulkner, S.P.

    2006-01-01

    Lower Mississippi Valley (LMV) has lost about 80% bottomland hardwood forests, mainly to agriculture. This landscape scale alteration of the LMV resulted in the loss of nitrate (NO3) removal capacity of the valley, contributing to nitrogen (N)-enhanced eutrophication and potentially hypoxia in the northern Gulf of Mexico. Restoration of hardwood forests in the LMV is a highly recommended practice to reduce NO3 load of the Mississippi River. However, restored bottomland forests take decades to develop characteristic ecological functions including denitrifier activity. One way to enhance denitrifier activity in restored wetland forests is to amend the soils with an available carbon (C) source. This research investigated the effects of cotton gin trash (CGT) amendment on denitrification rate and N2O:N2 emission ratio from a restored bottomland forest soils and compared it to those from an adjacent unamended natural forest soils. CGT amendment increased denitrification rates in the restored forest soils to the level of the natural forest soils. N2O:N2 emission ratios from the restored and natural forest soils were highly variable and were not significantly different from each other. These findings suggest that restoration of bottomland hardwood forests in the LMV will require organic carbon amendment to achieve enhanced denitrifier activity for NO3 removal while the restored forest is developing into a mature state over time. ?? 2006 Elsevier B.V. All rights reserved.

  11. The microbiomes and metagenomes of forest biochars

    PubMed Central

    Noyce, Genevieve L.; Winsborough, Carolyn; Fulthorpe, Roberta; Basiliko, Nathan

    2016-01-01

    Biochar particles have been hypothesized to provide unique microhabitats for a portion of the soil microbial community, but few studies have systematically compared biochar communities to bulk soil communities. Here, we used a combination of sequencing techniques to assess the taxonomic and functional characteristics of microbial communities in four-year-old biochar particles and in adjacent soils across three forest environments. Though effects varied between sites, the microbial community living in and around the biochar particles had significantly lower prokaryotic diversity and higher eukaryotic diversity than the surrounding soil. In particular, the biochar bacterial community had proportionally lower abundance of Acidobacteria, Planctomycetes, and β-Proteobacteria taxa, compared to the soil, while the eukaryotic biochar community had an 11% higher contribution of protists belonging to the Aveolata superphylum. Additionally, we were unable to detect a consistent biochar effect on the genetic functional potential of these microbial communities for the subset of the genetic data for which we were able to assign functions through MG-RAST. Overall, these results show that while biochar particles did select for a unique subset of the biota found in adjacent soils, effects on the microbial genetic functional potential appeared to be specific to contrasting forest soil environments. PMID:27212657

  12. The microbiomes and metagenomes of forest biochars

    NASA Astrophysics Data System (ADS)

    Noyce, Genevieve L.; Winsborough, Carolyn; Fulthorpe, Roberta; Basiliko, Nathan

    2016-05-01

    Biochar particles have been hypothesized to provide unique microhabitats for a portion of the soil microbial community, but few studies have systematically compared biochar communities to bulk soil communities. Here, we used a combination of sequencing techniques to assess the taxonomic and functional characteristics of microbial communities in four-year-old biochar particles and in adjacent soils across three forest environments. Though effects varied between sites, the microbial community living in and around the biochar particles had significantly lower prokaryotic diversity and higher eukaryotic diversity than the surrounding soil. In particular, the biochar bacterial community had proportionally lower abundance of Acidobacteria, Planctomycetes, and β-Proteobacteria taxa, compared to the soil, while the eukaryotic biochar community had an 11% higher contribution of protists belonging to the Aveolata superphylum. Additionally, we were unable to detect a consistent biochar effect on the genetic functional potential of these microbial communities for the subset of the genetic data for which we were able to assign functions through MG-RAST. Overall, these results show that while biochar particles did select for a unique subset of the biota found in adjacent soils, effects on the microbial genetic functional potential appeared to be specific to contrasting forest soil environments.

  13. Logging and Fire Effects in Siberian Boreal Forests

    NASA Astrophysics Data System (ADS)

    Kukavskaya, E.; Buryak, L.; Ivanova, G.; Kalenskaya, O.; Bogorodskaya, A.; Zhila, S.; McRae, D.; Conard, S. G.

    2013-12-01

    The Russian boreal zone supports a huge terrestrial carbon pool. Moreover, it is a tremendous reservoir of wood products concentrated mainly in Siberia. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and has potentially important climate feedbacks. In addition, both legal and illegal logging increase landscape complexity and fire hazard. We investigated a number of sites in different regions of Siberia to evaluate the impacts of fire and logging on fuel loads, carbon emissions, tree regeneration, soil respiration, and microbocenosis. We found large variations of fire and logging effects among regions depending on growing conditions and type of logging activity. Partial logging had no negative impact on forest conditions and carbon cycle. Illegal logging resulted in increase of fire hazard, and higher carbon emissions than legal logging. The highest fuel loads and carbon emissions were found on repeatedly burned unlogged sites where first fire resulted in total tree mortality. Repeated fires together with logging activities in drier conditions and on large burned sites resulted in insufficient regeneration, or even total lack of tree seedlings. Soil respiration was less on both burned and logged areas than in undisturbed forest. The highest structural and functional disturbances of the soil microbocenosis were observed on logged burned sites. Understanding current interactions between fire and logging is important for modeling ecosystem processes and for managers to develop strategies of sustainable forest management. Changing patterns in the harvest of wood products increase landscape complexity and can be expected to increase emissions and ecosystem damage from wildfires, inhibit recovery of natural ecosystems, and exacerbate impacts of wildland fire on changing climate and air quality. The research was supported by NASA LCLUC Program, RFBR grant # 12-04-31258, and Russian Academy of Sciences.

  14. Translocation of Sb and Ti in an undisturbed floodplain soil after application of Sb2O3 and TiO2 nanoparticles to the surface.

    PubMed

    Duester, Lars; Prasse, Carsten; Vogel, Julia V; Vink, Jos P M; Schaumann, Gabriele E

    2011-05-01

    The pore water transport of antimony and titanium, applied as nanoparticles (NPs), was studied by spiking stable suspensions of two different nanomaterials on the surface of an undisturbed floodplain soil. For preparation of stable dispersions, two different strategies were followed. (i) Comparable to those used in industrial applications: titanium dioxide nanoparticles, with an average diameter of 99 nm, were prepared by high-energy ball milling in water, whereas for (ii) antimony trioxide (Sb(2)O(3); average diameter 121 nm) a dispersing agent (sodium salt of poly[(naphthaleneformaldehyde)sulfonate] (pNFS) in water) was used. The upper 17 cm of a floodplain soil (river Rhine, Germany) was sampled using the minimally invasive sediment or fauna incubation experiment (SOFIE® two compartment cell; 3 l volume each), which preserved the pore system of the soil. The cells were equipped with 450 and 100 nm filter probes at different depths providing a non-invasive sampling of the pore water. The pore water was sampled at different times (T = 0, 24, 48, 96 and 196 h) and analysed by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Sb and Ti were transported via the pore water of the floodplain soil to a depth of 14 cm, corresponding to the maximum cell depth. The highest Sb concentration in the pore water was detected after 24 h at a depth of 5.5-8 cm. Although the spiked concentration was higher for Ti than for Sb, the total Ti concentration in the pore water of the spiked cell was lower. This indicates a stronger agglomeration of TiO(2) NPs or a more intensive interaction of Ti with the solid matrix and a faster transport of Sb towards deeper soil layers. The results show that metal(loid)s from metal oxide NPs are transported in the soil pore water and, hence, have the potential to act as the source of contamination of deeper soil layers after soil surface contamination.

  15. Factors affecting songbird nest survival in riparian forests in a Midwestern agricultural landscape

    USGS Publications Warehouse

    Peak, R.G.; Thompson, F. R.; Shaffer, T.L.

    2004-01-01

    We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55DS95 m) and three wide (400DS530 m) riparian forests with adjacent grasslandDSshrub buffer strips and in three narrow and three wide riparian forests without adjacent grasslandDSshrub buffer strips. We predicted that temporal effects would have the most support and that habitat-patch and edge effects would have little support, because nest predation would be great across all sites in the highly fragmented, predominantly agricultural landscape. Interval nest success was 0.404, 0.227, 0.070, and 0.186, respectively, for Gray Catbird (Dumetella carolinensis), Northern Cardinal (Cardinalis cardinalis), Indigo Bunting (Passerina cyanea), and forest interior species pooled (Acadian Flycatcher [Empidonax virescens], Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapillus], and Kentucky Warbler [Oporornis formosus]). The effect of nest stage on nest success had the most support; daily nest success for Gray Catbird and Indigo Bunting were lowest in the laying stage. We found strong support for greater nest success of Gray Catbird in riparian forests with adjacent buffer strips than in riparian forests without adjacent buffer strips. Patch width also occurred in the most supported model for Gray Catbird, but with very limited support. The null model received the most support for Northern Cardinal. Riparian forests provided breeding habitat for areas sensitive forest species and grassland-shrub nesting species. Buffer strips provided additional breeding habitat for grassland-shrub nesting species. Interval nest success for Indigo Bunting and area-sensitive forest species pooled, however, fell well below the level that is likely necessary to balance

  16. Factors affecting songbird nest survival in riparian forests in a midwestern agricultural landscape

    USGS Publications Warehouse

    Peak, R.G.; Thompson, F. R.; Shaffer, T.L.

    2004-01-01

    We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55-95 m) and three wide (400-530 m) riparian forests with adjacent grassland-shrub buffer strips and in three narrow and three wide riparian forests without adjacent grassland-shrub buffer strips. We predicted that temporal effects would have the most support and that habitat-patch and edge effects would have little support, because nest predation would be great across all sites in the highly fragmented, predominantly agricultural landscape. Interval nest success was 0.404, 0.227, 0.070, and 0.186, respectively, for Gray Catbird (Dumetella carolinensis), Northern Cardinal (Cardinalis cardinalis), Indigo Bunting (Passerina cyanea), and forest interior species pooled (Acadian Flycatcher [Empidonax virescens], Wood Thrush [Hylocichla mustelina], Ovenbird [Seiurus aurocapillus], and Kentucky Warbler [Oporornis formosus]). The effect of nest stage on nest success had the most support; daily nest success for Gray Catbird and Indigo Bunting were lowest in the laying stage. We found strong support for greater nest success of Gray Catbird in riparian forests with adjacent buffer strips than in riparian forests without adjacent buffer strips. Patch width also occurred in the most-supported model for Gray Catbird, but with very limited support. The null model received the most support for Northern Cardinal. Riparian forests provided breeding habitat for area-sensitive forest species and grassland-shrub nesting species. Buffer strips provided additional breeding habitat for grassland-shrub nesting species. Interval nest success for Indigo Bunting and area-sensitive forest species pooled, however, fell well below the level that is likely necessary to balance juvenile

  17. Nitrogen dynamics across silvicultural canopy gaps in young forests of western Oregon

    USGS Publications Warehouse

    Thiel, A.L.; Perakis, S.S.

    2009-01-01

    Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. The effect of gap creation on available nitrogen (N) is of concern to managers because N is often a limiting nutrient in Pacific Northwest forests. We investigated patterns of N availability in the forest floor and upper mineral soil (0-10 cm) across 6-8-year-old silvicultural canopy gaps in three 50-70-year-old Douglas-fir forests spanning a wide range of soil N capital in the Coast Range and Cascade Mountains of western Oregon. We used extractable ammonium (NH4+) and nitrate (NO3-) pools, net N mineralization and nitrification rates, and NH4+ and NO3- ion exchange resin (IER) concentrations to quantify N availability along north-south transects run through the centers of 0.4 and 0.1 ha gaps. In addition, we measured several factors known to influence N availability, including litterfall, moisture, temperature, and decomposition rates. In general, gap-forest differences in N availability were more pronounced in the mineral soil than in the forest floor. Mineral soil extractable NH4+ and NO3- pools, net N mineralization and nitrification rates, and NH4+ and NO3- IER concentrations were all significantly elevated in gaps relative to adjacent forest, and in several cases exhibited significantly greater spatial variability in gaps than forest. Nitrogen availability along the edges of gaps more often resembled levels in the adjacent forest than in gap centers. For the majority of response variables, there were no significant differences between northern and southern transect positions, nor between 0.4 and 0.1 ha gaps. Forest floor and mineral soil gravimetric percent moisture and temperature showed few differences along transects, while litterfall carbon (C) inputs and litterfall C:N ratios in gaps were significantly lower than in the adjacent forest. Reciprocal transfer incubations of

  18. Climate change and forests.

    PubMed

    Gates, David M.

    1990-12-01

    Factors governing long-term change in global temperature are reviewed. The magnitude and rate of change in global temperature resulting from current increases in the concentration of atmospheric greenhouse gases are considered in relation to their impact on forests. Movement in forest zone boundaries at a rate of 2.5 km year(-1) are possible, which is nearly ten times the rate forests have been known to move by natural reproduction. Climate models indicate that increased global temperature will affect rainfall distribution, lead to more frequent and more severe storms and increase climatic variability. Consequences for the world's forests include increased frequencies of fire and blow-down, and wide-spread decline. Increased atmospheric CO(2) concentrations may increase forest growth where the effect is not offset by reduced precipitation, but the overall effect of anticipated changes in global climate is likely to be widespread loss of forests.

  19. 78 FR 18307 - Forest Service

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting; Correction. SUMMARY: The Forest Service published a document in the Federal Register of January 31, 2013, concering a notice of meeting for the Forest Resource Coordinating Committee. The...

  20. Forest management and economics

    SciTech Connect

    Buongiorno, J.; Gilless, J.K.

    1987-01-01

    This volume provides a survey of quantitative methods, guiding the reader through formulation and analysis of models that address forest management problems. The authors use simple mathematics, graphics, and short computer programs to explain each method. Emphasizing applications, they discuss linear, integer, dynamic, and goal programming; simulation; network modeling; and econometrics, as these relate to problems of determining economic harvest schedules in even-aged and uneven-aged forests, the evaluation of forest policies, multiple-objective decision making, and more.

  1. Forest Fires in a Random Forest

    NASA Astrophysics Data System (ADS)

    Leuenberger, Michael; Kanevski, Mikhaïl; Vega Orozco, Carmen D.

    2013-04-01

    Forest fires in Canton Ticino (Switzerland) are very complex phenomena. Meteorological data can explain some occurrences of fires in time, but not necessarily in space. Using anthropogenic and geographical feature data with the random forest algorithm, this study tries to highlight factors that most influence the fire-ignition and to identify areas under risk. The fundamental scientific problem considered in the present research deals with an application of random forest algorithms for the analysis and modeling of forest fires patterns in a high dimensional input feature space. This study is focused on the 2,224 anthropogenic forest fires among the 2,401 forest fire ignition points that have occurred in Canton Ticino from 1969 to 2008. Provided by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), the database characterizes each fire by their location (x,y coordinates of the ignition point), start date, duration, burned area, and other information such as ignition cause and topographic features such as slope, aspect, altitude, etc. In addition, the database VECTOR25 from SwissTopo was used to extract information of the distances between fire ignition points and anthropogenic structures like buildings, road network, rail network, etc. Developed by L. Breiman and A. Cutler, the Random Forests (RF) algorithm provides an ensemble of classification and regression trees. By a pseudo-random variable selection for each split node, this method grows a variety of decision trees that do not return the same results, and thus by a committee system, returns a value that has a better accuracy than other machine learning methods. This algorithm incorporates directly measurement of importance variable which is used to display factors affecting forest fires. Dealing with this parameter, several models can be fit, and thus, a prediction can be made throughout the validity domain of Canton Ticino. Comprehensive RF analysis was carried out in order to 1

  2. Within-canopy sampling of global irradiance to describe downwelling light distribution and infer canopy stratification in a broadleaf forest.

    PubMed

    Giuliani, Rita; Brown, Kim J

    2008-09-01

    A broadleaf mixed forest diversified through partial tree thinning was studied to identify expedient sampling and data analysis procedures to capture the heterogeneous within-canopy downward distribution of instantaneous global photosynthetic photon flux (PPF); to extract foliage structural properties from the acquired light values; and to compute statistics descriptive of the within-canopy light and leaf layer distributions. We sampled PPF at 1-m intervals along vertical gradients using a helium-filled balloon as a platform for a light sensor. A random method was used to identify the forest floor locations for the within-canopy balloon ascents. About 400 PPF measurements were recorded per vertical transect. For each PPF value, we computed, by inversion of the Monsi-Saeki model, the number of leaf strata cumulated along the sunbeam direction from the position where the light was measured. Variability in PPF and leaf layer at different vegetation scales was computed by non-parametric statistics. The methods were evaluated as appropriate for intra-canopy PPF sampling, particularly in an undisturbed canopy. The minimum number of vertical PPF profiles required to capture the within-canopy PPF variability was 9-10 (equivalent to about 4000 measurements). The reliability and sensitivity of the inversion of the Monsi-Saeki method were sufficient to capture the canopy structural differences between undisturbed and partially thinned forests. The proposed PPF canopy sampling and data analysis procedures provide a fast, reliable and inexpensive way to characterize tree crown structure, and to predict plant growth and forest dynamics and could be applied whenever vegetation absorbed radiation is a main driving force for forest canopy processes. The experimental light attenuation data and the extracted canopy leaf layer numbers could serve to corroborate canopy mechanistic models of radiative transfer and net primary production.

  3. 7. View southwest, east facade of Lake Forest (original Forest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View southwest, east facade of Lake Forest (original Forest Cottage structure incorporated into renamed structure) - Lake Placid Club, Forest Wing, East side of Mirror Lake Drive, North of State Route 86 & Main, North Elba, Essex County, NY

  4. 3. View northeast, west facade of Lake Forest (original Forest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View northeast, west facade of Lake Forest (original Forest Cottage structure incorporated into renamed structure) - Lake Placid Club, Forest Wing, East side of Mirror Lake Drive, North of State Route 86 & Main, North Elba, Essex County, NY

  5. 4. View southeast, west facade of Lake Forest (original Forest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View southeast, west facade of Lake Forest (original Forest Cottage structure incorporated into renamed structure) - Lake Placid Club, Forest Wing, East side of Mirror Lake Drive, North of State Route 86 & Main, North Elba, Essex County, NY

  6. Surgical treatment of complex axis fractures with adjacent segment instability.

    PubMed

    Wang, Lei; Xia, Tian; Dong, Shuanghai; Zhao, Qinghua; Tian, Jiwei

    2012-03-01

    This study investigates the clinical and radiographic characteristics of complex axis fractures with adjacent segment instability and describes the outcome of surgical treatment. Twenty-one patients (14 male, seven female; mean age=34 years) with complex axis fractures and adjacent segment instability who were treated between August 2003 and June 2009 were retrospectively reviewed. Treatment selection was based on fracture type and stability of the upper cervical segments. All patients were immobilized with a hard collar for three months after surgery. The mean follow-up period was 12 months (range=6-36 months). No intraoperative surgery-related complications were observed and fusion was achieved in all patients. The outcome was excellent for 17 patients, good for two patients, fair for one patient, and poor for one patient. The upper cervical segments that can become unstable due to complex axis fractures include the atlantoaxial and C2-3 joints. Recommended surgical treatments produce good results.

  7. On the Circulation Manifold for Two Adjacent Lifting Sections

    NASA Technical Reports Server (NTRS)

    Zannetti, Luca; Iollo, Angelo

    1998-01-01

    The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining the two centers and of the angle of attack of the secondary circle, The gradient of such functional is computed by deriving a set of elliptic functions with respect both to their argument and to their Period. In the second case studied, we considered a wing-flap configuration. The circulation is computed by some implicit mappings, whose differentials with respect to the variation of the geometrical configuration in the physical space are found by divided differences. Configurations giving rise to local maxima and minima in the circulation manifold are presented.

  8. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  9. Conference room 211, adjacent to commander's quarters, with vault door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Conference room 211, adjacent to commander's quarters, with vault door at right. Projection area at center is equipped with automatic security drapes. Projection room uses a 45 degree mirror to reflect the image onto the frosted glass screen. Door on far left leads to display area senior battle staff viewing bridge, and the commander's quarters - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  10. 20. Interior view of fuel storage pit or vault adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  11. Four-body central configurations with adjacent equal masses

    NASA Astrophysics Data System (ADS)

    Deng, Yiyang; Li, Bingyu; Zhang, Shiqing

    2017-04-01

    For any convex non-collinear central configuration of the planar Newtonian 4-body problem with adjacent equal masses m1 =m2 ≠m3 =m4, with equal lengths for the two diagonals, we prove it must possess a symmetry and must be an isosceles trapezoid; furthermore, which is also an isosceles trapezoid when the length between m1 and m4 equals the length between m2 and m3.

  12. Processing multiple non-adjacent dependencies: evidence from sequence learning.

    PubMed

    de Vries, Meinou H; Petersson, Karl Magnus; Geukes, Sebastian; Zwitserlood, Pienie; Christiansen, Morten H

    2012-07-19

    Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3)_B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1)_B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i.e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.

  13. 38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX GAP ROTARY RECTIFIER. THIS UNIT GENERATED A MAGNETIC PULSE WHICH WAS TRANSMITTED TO THE COLLECTION PLATES IN THE ELECTROSTATIC PRECIPITATOR CHAMBER. THESE PERIODIC PULSES VIBRATE THE PLATES AND CAUSE PRECIPITATED ARTICLES OF SMOKE AND FLY ASH TO FALL TO THE BOTTOM OF THE PRECIPITATOR CHAMBER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  14. 30 CFR 784.28 - Surface activities in or adjacent to perennial or intermittent streams.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... itself, and those activities would occur on the surface of land subject to the buffer requirement of... buffer that you propose to implement instead of maintaining a 100-foot undisturbed buffer between surface activities and the perennial or intermittent stream; and (3) Explain how the lesser buffer, together with...

  15. Divergent viral presentation among human tumors and adjacent normal tissues

    PubMed Central

    Cao, Song; Wendl, Michael C.; Wyczalkowski, Matthew A.; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J.; Gay, Hiram; Chen, Ken; Rader, Janet S.; Dipersio, John F.; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  16. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage ‘Ci’ given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage ‘Ci’ decreased as both the adjacent P1 and M1 matured. The modal stage at P2 ‘Ci’ was P1 ‘Coc’ (cusp outline complete) and M1 ‘Crc’ (crown complete). Initial mineralisation of P2 was observed up to P1 ‘Crc’ and M1 stage ‘R½’ (root half). The chance of observing P2 at least ‘Coc’ (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond ‘Crc’ and M1 is beyond ‘R½’. PMID:26673218

  17. Adjacent Segment Disease in the Cervical and Lumbar Spine.

    PubMed

    Tobert, Daniel G; Antoci, Valentin; Patel, Shaun P; Saadat, Ehsan; Bono, Christopher M

    2017-04-01

    Adjacent segment disease (ASD) is disappointing long-term outcome for both the patient and clinician. In contrast to adjacent segment degeneration, which is a common radiographic finding, ASD is less common. The incidence of ASD in both the cervical and lumbar spine is between 2% and 4% per year, and ASD is a significant contributor to reoperation rates after spinal arthrodesis. The etiology of ASD is multifactorial, stemming from existing spondylosis at adjacent levels, predisposed risk to degenerative changes, and altered biomechanical forces near a previous fusion site. Numerous studies have sought to identify both patient and surgical risk factors for ASD, but a consistent, sole predictor has yet to be found. Spinal arthroplasty techniques seek to preserve physiological biomechanics, thereby minimizing the risk of ASD, and long-term clinical outcome studies will help quantify its efficacy. Treatment strategies for ASD are initially nonoperative, provided a progressive neurological deficit is not present. The spine surgeon is afforded many surgical strategies once operative treatment is elected. The goal of this manuscript is to consider the etiologies of ASD, review its manifestations, and offer an approach to treatment.

  18. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  19. Perceptual processing of adjacent and nonadjacent tactile nontargets.

    PubMed

    Evans, P M; Craig, J C; Rinker, M A

    1992-11-01

    Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

  20. Using BRDFs for accurate albedo calculations and adjacency effect corrections

    SciTech Connect

    Borel, C.C.; Gerstl, S.A.W.

    1996-09-01

    In this paper the authors discuss two uses of BRDFs in remote sensing: (1) in determining the clear sky top of the atmosphere (TOA) albedo, (2) in quantifying the effect of the BRDF on the adjacency point-spread function and on atmospheric corrections. The TOA spectral albedo is an important parameter retrieved by the Multi-angle Imaging Spectro-Radiometer (MISR). Its accuracy depends mainly on how well one can model the surface BRDF for many different situations. The authors present results from an algorithm which matches several semi-empirical functions to the nine MISR measured BRFs that are then numerically integrated to yield the clear sky TOA spectral albedo in four spectral channels. They show that absolute accuracies in the albedo of better than 1% are possible for the visible and better than 2% in the near infrared channels. Using a simplified extensive radiosity model, the authors show that the shape of the adjacency point-spread function (PSF) depends on the underlying surface BRDFs. The adjacency point-spread function at a given offset (x,y) from the center pixel is given by the integral of transmission-weighted products of BRDF and scattering phase function along the line of sight.

  1. Bi-Temporal Analysis of High-Resolution Satellite Imagery in Support of a Forest Conservation Program in Western Uganda

    NASA Astrophysics Data System (ADS)

    Thomas, N.; Lambin, E.; Audy, R.; Biryahwaho, B.; de Laat, J.; Jayachandran, S.

    2014-12-01

    Recent studies in land use sustainability have shown the conservation value of even small forest fragments in tropical smallholder agricultural regions. Forest patches provide important ecosystem services, wildlife habitat, and support human livelihoods. Our study incorporates multiple dates of high-resolution Quickbird imagery to map forest disturbance and regrowth in a smallholder agricultural landscape in western Uganda. This work is in support of a payments for ecosystem services (PES) project which uses a randomized controlled trial to assess the efficacy of PES for enhancing forest conservation. The research presented here details the remote sensing phase of this project. We developed an object-based methodology for detecting forest change from high-resolution imagery that calculates per class image reflectance and change statistics to determine persistent forest, non-forest, forest gain, and forest loss classes. The large study area (~ 2,400 km2) necessitated using a combination of 10 different image pairs of varying seasonality, sun angle, and viewing angle. We discuss the impact of these factors on mapping results. Reflectance data was used in conjunction with texture measures and knowledge-driven modeling to derive forest change maps. First, baseline Quickbird images were mapped into tree cover and non-tree categories based on segmented image objects and field inventory data, applied through a classification and regression tree (CART) classifier. Then a bi-temporal segmentation layer was generated and a series of object metrics from both image dates were extracted. A sample set of persistent forest objects that remained undisturbed was derived from the tree cover map and the red band (B3) change values. We calculated a variety of statistical indices for these persistent tree cover objects from the post- survey imagery to create maps of both forest cover loss and forest cover gain. These results are compared to visually assessed image objects in addition

  2. Life in Tropical Rain Forests.

    ERIC Educational Resources Information Center

    NatureScope, 1989

    1989-01-01

    Discusses the diversity of rain forest life, the adaptations of rain forest plants and animals, and ways these organisms interact. Includes activities on canopy critters with a copyable sheet, rain forest revue, design a plant, and jungle sleuths. (RT)

  3. Effects of landscape design of forest reserves on Saproxylic beetle diversity.

    PubMed

    Bouget, C; Parmain, G

    2016-02-01

    Increasing the density of natural reserves in the forest landscape may provide conservation benefits for biodiversity within and beyond reserve borders. We used 2 French data sets on saproxylic beetles and landscape cover of forest reserves (LCFR) to test this hypothesis: national standardized data derived from 252 assessment plots in managed and reserve stands in 9 lowland and 5 highland forests and data from the lowland Rambouillet forest, a forested landscape where a pioneer conservation policy led to creation of a dense network of reserves. Abundance of rare and common saproxylic species and total saproxylic species richness were higher in forest reserves than in adjacent managed stands only in highland forests. In the lowland regional case study, as LCFR increased total species richness and common species abundance in reserves increased. In this case study, when there were two or more reserve patches, rare species abundance inside reserves was higher and common species richness in managed stands was higher than when there was a single large reserve. Spillover and habitat amount affected ecological processes underlying these landscape reserve effects. When LCFR positively affected species richness and abundance in reserves or managed stands, >12-20% reserve cover led to the highest species diversity and abundance. This result is consistent with the target of 17% forested land area in reserves set at the Nagoya biodiversity summit in 2010. Therefore, to preserve biodiversity we recommend at least doubling the current proportion of forest reserves in European forested landscapes.

  4. Expansion of forest stands into tundra in the Noatak National Preserve, northwest Alaska

    USGS Publications Warehouse

    Suarez, F.; Binkley, D.; Kaye, M.W.; Stottlemyer, R.

    1999-01-01

    Temperatures across the northern regions of North America have been increasing for 150 years, and forests have responded to this increase. In the Noatak National Preserve in Alaska, white spruce (Picea glauca [Moench] Voss) forests reach their northern limit, occurring primarily on well-drained sites and as gallery forests along streams. Rolling plateaus of tundra separate the white spruce forests into disjunct stands. We examined patterns of tree age, tree growth, and tree encroachment into tundra ecosystems in six stands along the Agashashok River. Warming over the past 150 years appears to have increased tree growth and resulted in forest expansion into adjacent tundra ecosystems. The forest/tundra ecotone shifted by about 80 to 100 m into the tundra in the past 200 years, as evidenced by declining maximum tree age with distance towards the tundra. The decadal-scale pattern of tree establishment at the farthest extent of trees into the tundra (the tundra-forest ecotone) correlated with the detrended growth index for trees within the forests; climate conditions that led to higher tree growth appeared to foster tree establishment in the tundra. This recent forest expansion has occurred across topographic boundaries, from well-drained soils on slopes onto poorly drained, flatter areas of tundra. Further expansion of the forests may be limited by more severe wind exposure and poor drainage that make the majority of tundra less suitable for trees.

  5. Managing the world's forests.

    PubMed

    Sharma, N; Rowe, R

    1992-06-01

    Forests play a vital role in balancing natural systems: the stabilization of global climate and the management of water and land. 30% of the earth's total land area is forested. 66% of the tropical moist forests are in Latin America and the remainder in Africa and Asia. 75% of tropical dry forests are in Africa. Temperate forests are primarily in developed countries. Deforestation and misuse of forests occurs primarily in developing countries at significant social, economic, and environmental costs. Losses have occurred in fuelwood, fodder, timber, forest products, biological diversity, habitats, genetic materials for food and medicine. The World Bank's evolving role in forestry is briefly described. Agreement has not been reached among people or nations about the most appropriate means to balance conservation and development goals. The challenge is to stabilize existing forests and increase forest planting. The causes of forest degradation must be understood. Direct causes include agricultural encroachment, cattle ranching, fuelwood gathering, commercial logging, and infrastructure development. These direct causes are driven by economic, social, and political forces: market and policy failures, population growth, and poverty. The market failures include: 1) the lack of clearly defined property rights on forest resources for now and the future, 2) the conflict between individual and societal needs, 3) the difficulty in placing a value on nonmarket environmental services and joint products, and 4) the separation between private and social costs. The solution is action at the local, national, and global levels. Countries must establish forest policy. The existing government incentives which promote deforestation must be changed. For example, concession policy and royalty systems must be corrected; explicit and implicit export subsidies on timber and forest products must be stopped. Private incentives must be established to promote planting of trees, practicing

  6. Floodplains as an Achilles' heel of Amazonian forest resilience.

    PubMed

    Flores, Bernardo M; Holmgren, Milena; Xu, Chi; van Nes, Egbert H; Jakovac, Catarina C; Mesquita, Rita C G; Scheffer, Marten

    2017-04-10

    The massive forests of central Amazonia are often considered relatively resilient against climatic variation, but this view is challenged by the wildfires invoked by recent droughts. The impact of such fires that spread from pervasive sources of ignition may reveal where forests are less likely to persist in a drier future. Here we combine field observations with remotely sensed information for the whole Amazon to show that the annually inundated lowland forests that run through the heart of the system may be trapped relatively easily into a fire-dominated savanna state. This lower forest resilience on floodplains is suggested by patterns of tree cover distribution across the basin, and supported by our field and remote sensing studies showing that floodplain fires have a stronger and longer-lasting impact on forest structure as well as soil fertility. Although floodplains cover only 14% of the Amazon basin, their fires can have substantial cascading effects because forests and peatlands may release large amounts of carbon, and wildfires can spread to adjacent uplands. Floodplains are thus an Achilles' heel of the Amazon system when it comes to the risk of large-scale climate-driven transitions.

  7. Microbial Community Structure and Function of Soil Following Ecosystem Conversion from Native Forests to Teak Plantation Forests

    PubMed Central

    de Gannes, Vidya; Bekele, Isaac; Dipchansingh, Denny; Wuddivira, Mark N.; De Cairies, Sunshine; Boman, Mattias; Hickey, William J.

    2016-01-01

    Soil microbial communities can form links between forest trees and functioning of forest soils, yet the impacts of converting diverse native forests to monoculture plantations on soil microbial communities are limited. This study tested the hypothesis that conversion from a diverse native to monoculture ecosystem would be paralleled by a reduction in the diversity of the soil microbial communities. Soils from Teak (Tectona grandis) plantations and adjacent native forest were examined at two locations in Trinidad. Microbial community structure was determined via Illumina sequencing of bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) regions, and by phospholipid fatty acid (PLFA) analysis. Functional characteristics of microbial communities were assessed by extracellular enzyme activity (EEA). Conversion to Teak plantation had no effect on species richness or evenness of bacterial or fungal communities, and no significant effect on EEA. However, multivariate analyses (nested and two-way crossed analysis of similarity) revealed significant effects (p < 0.05) of forest type (Teak vs. native) upon the composition of the microbial communities as reflected in all three assays of community structure. Univariate analysis of variance identified two bacterial phyla that were significantly more abundant in the native forest soils than in Teak soils (Cyanobacteria, p = 0.0180; Nitrospirae, p = 0.0100) and two more abundant in Teak soils than in native forest (candidate phyla TM7, p = 0.0004; WS6, p = 0.044). Abundance of an unidentified class of arbuscular mycorrhizal fungi (AMF) was significantly greater in Teak soils, notable because Teak is colonized by AMF rather than by ectomycorrihzal fungi that are symbionts of the native forest tree species. In conclusion, microbial diversity indices were not affected in the conversion of native forest to teak plantation, but examination of specific bacterial taxa showed that there were significant differences in

  8. Developing New Coastal Forest Restoration Products Based on Landsat, ASTER, and MODIS Data

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.; Graham, William; Smoot, James

    2009-01-01

    This paper discusses an ongoing effort to develop new geospatial information products for aiding coastal forest restoration and conservation efforts in coastal Louisiana and Mississippi. This project employs Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data in conjunction with airborne elevation data to compute coastal forest cover type maps and change detection products. Improved forest mapping products are needed to aid coastal forest restoration and management efforts of State and Federal agencies in the Northern Gulf of Mexico (NGOM) region. In particular, such products may aid coastal forest land acquisition and conservation easement procurements. This region's forests are often disturbed and subjected to multiple biotic and abiotic threats, including subsidence, salt water intrusion, hurricanes, sea-level rise, insect-induced defoliation and mortality, altered hydrology, wildfire, and conversion to non-forest land use. In some cases, such forest disturbance has led to forest loss or loss of regeneration capacity. In response, a case study was conducted to assess and demonstrate the potential of satellite remote sensing products for improving forest type maps and for assessing forest change over the last 25 years. Change detection products are needed for assessing risks for specific priority coastal forest types, such as live oak and baldcypress-dominated forest. Preliminary results indicate Landsat time series data are capable of generating the needed forest type and change detection products. Useful classifications were obtained using 2 strategies: 1) general forest classification based on use of 3 seasons of Landsat data from the same year; and 2) classification of specific forest types of concern using a single date of Landsat data in which a given targeted type is spectrally distinct compared to adjacent forested cover. When available, ASTER data was

  9. A simulation model of water depth in mangrove basin forests.

    PubMed

    Ritchie, S A

    1990-06-01

    The construction and validation of a model simulating the water depth within mangrove basin forests is described. Rainfall, water table, water depth and tide data collected from a red mangrove basin forest on Marco Island, FL, was used to estimate model parameters. These included the basin spillover height, evapotranspiration-infiltration rate and the functional relationship of water depth change to rainfall, tide and basin spillover. The model was constructed with LOTUS 123 and calibrated from staff gauge water depth records. The model proved accurate and adaptable. Water depths from the model and staff gauge were correlated highly (r = 0.98). Data from an adjacent black mangrove forest featuring complex wet-dry cycling were used to modify the model. After calibration, the model provided an accurate record of water depths at the site (r = 0.89). This model will provide water depths used in a model of Aedes taeniorhynchus population dynamics.

  10. Predicting primate local extinctions within "real-world" forest fragments: a pan-neotropical analysis.

    PubMed

    Benchimol, Maíra; Peres, Carlos A

    2014-03-01

    Understanding the main drivers of species extinction in human-modified landscapes has gained paramount importance in proposing sound conservation strategies. Primates play a crucial role in maintaining the integrity of forest ecosystem functions and represent the best studied order of tropical terrestrial vertebrates, yet primate species diverge widely in their responses to forest habitat disturbance and fragmentation. Here, we present a robust quantitative review on the synergistic effects of habitat fragmentation on Neotropical forest primates to pinpoint the drivers of species extinction across a wide range of forest patches from Mexico to Argentina. Presence-absence data on 19 primate functional groups were compiled from 705 forest patches and 55 adjacent continuous forest sites, which were nested within 61 landscapes investigated by 96 studies. Forest patches were defined in terms of their size, surrounding matrix and level of hunting pressure on primates, and each functional group was classified according to seven life-history traits. Generalized linear mixed models showed that patch size, forest cover, level of hunting pressure, home range size and trophic status were the main predictors of species persistence within forest isolates for all functional groups pooled together. However, patterns of local extinction varied greatly across taxa, with Alouatta and Callicebus moloch showing the highest occupancy rates even within tiny forest patches, whereas Brachyteles and Leontopithecus occupied fewer than 50% of sites, even in relatively large forest tracts. Our results uncover the main predictors of platyrrhine primate species extinction, highlighting the importance of considering the history of anthropogenic disturbances, the structure of landscapes, and species life-history attributes in predicting primate persistence in Neotropical forest patches. We suggest that large-scale conservation planning of fragmented forest landscapes should prioritize and set

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  12. Impact of Conifer Forest Litter on Microwave Emission at L-Band

    NASA Technical Reports Server (NTRS)

    Kurum, Mehmet; O'Neill, Peggy E.; Lang, Roger H.; Cosh, Michael H.; Joseph, Alicia T.; Jackson, Thomas J.

    2011-01-01

    This study reports on the utilization of microwave modeling, together with ground truth, and L-band (1.4-GHz) brightness temperatures to investigate the passive microwave characteristics of a conifer forest floor. The microwave data were acquired over a natural Virginia Pine forest in Maryland by a ground-based microwave active/passive instrument system in 2008/2009. Ground measurements of the tree biophysical parameters and forest floor characteristics were obtained during the field campaign. The test site consisted of medium-sized evergreen conifers with an average height of 12 m and average diameters at breast height of 12.6 cm. The site is a typical pine forest site in that there is a surface layer of loose debris/needles and an organic transition layer above the mineral soil. In an effort to characterize and model the impact of the surface litter layer, an experiment was conducted on a day with wet soil conditions, which involved removal of the surface litter layer from one half of the test site while keeping the other half undisturbed. The observations showed detectable decrease in emissivity for both polarizations after the surface litter layer was removed. A first-order radiative transfer model of the forest stands including the multilayer nature of the forest floor in conjunction with the ground truth data are used to compute forest emission. The model calculations reproduced the major features of the experimental data over the entire duration, which included the effects of surface litter and ground moisture content on overall emission. Both theory and experimental results confirm that the litter layer increases the observed canopy brightness temperature and obscure the soil emission.

  13. Evaluation of Forest Recovery over Time and Space Using Permanent Plots Monitored over 30 Years in a Jamaican Montane Rain Forest

    PubMed Central

    Chai, Shauna-Lee; Healey, John R.; Tanner, Edmund V. J.

    2012-01-01

    Conservation of tropical forest biodiversity increasingly depends on its recovery following severe human disturbance. Our ability to measure recovery using current similarity indices suffers from two limitations: different sized individuals are treated as equal, and the indices are proportionate (a community with twice the individuals of every species as compared with the reference community would be assessed as identical). We define an alternative recovery index for trees – the Tanner index, as the mean of the quantitative Bray-Curtis similarity indices of species composition for stem density and for basal area. We used the new index to compare the original (pre-gap) and post-gap composition of five experimental gap plots (each 90–100 m2) and four control plots over 24–35 years in the Blue Mountains of Jamaica. After 24–35 years, these small gaps surrounded by undisturbed forest had recovered 68% of the sum of per species stem density and 29% of the sum of per species basal area, a recovery index of 47%. Four endemic species were especially reduced in density and basal area. With the incorporation of basal area and stem density, our index reduces over-estimations of forest recovery obtained using existing similarity indices (by 24%–41%), and thus yields more accurate estimates of forest conservation status. Finally, our study indicates that the two kinds of comparisons: 1) over time between pre-gap and post-gap composition and 2) over space between gap plots and spatial controls (space-for-time substitution) yield broadly similar results, which supports the value of using space-for-time substitutions in studying forest recovery, at least in this tropical montane forest. PMID:23155417

  14. Contrasting impact of forestry-drainage on CO2 balance at two adjacent peatlands in Finland

    NASA Astrophysics Data System (ADS)

    Lohila, Annalea; Minkkinen, Kari; Penttilä, Timo; Launiainen, Samuli; Koskinen, Markku; Ojanen, Paavo; Laurila, Tuomas

    2014-05-01

    Fate of carbon in peatlands after drainage has been a subject of many studies, particularly at agriculturally managed sites, but also at sites prepared for forestry. In general, the drainage of peatlands has been considered to trigger the decomposition rate of peat and to cause carbon dioxide (CO2) emissions from the peat into the atmosphere. However, there is not yet full consensus on what are the main regulating factors of the carbon balances in forested peatlands, and do all the forested peatland even act as a source of carbon into the atmosphere. In this study we compare the CO2 exchange rates at two adjacent peatland sites in southern Finland, drained for forestry about 40 years earlier. The pair of sites with similar climatic conditions offer an excellent case for studying the mechanisms controlling the carbon balances of forestry-drained peatlands. The sites differ from each other only by fertility, which has an impact on, e.g., tree growth rate. At both sites, CO2 and energy fluxes have been measured with the eddy covariance method over the course of 4 years, but not simultaneously. We have also built at both sites an automatic system consisting of six transparent closed chambers which collect data on the CO2 exchange of the forest floor vegetation (including tree roots) and soil around the year. This enables us to quantify the carbon uptake potential of the ground layer and the peat decomposition rates and helps us to understand the differences between the sites. The results show that the pine and dwarf-shrub-dominated site (nutrient-poor) is a large CO2 sink. The site with a mixture of spruce, birch and pine and lesser ground vegetation (nutrient-rich), on the contrary, has a close-to-neutral CO2 balance, despite the much higher tree growth rate there. In this presentation we will compare the general dynamics and climatic responses of CO2 exchange at the sites, compare the magnitude and factors causing interannual variation, and discuss potential reasons

  15. People and Forests.

    ERIC Educational Resources Information Center

    NatureScope, 1986

    1986-01-01

    Provides: (1) background information on how forests are managed and some of the problems facing forests around the world; (2) three activities dealing with these topics; and (3) three ready-to-copy pages for student use. Activities include an objective, recommended age level(s), recommended subject area(s), list of materials needed, and…

  16. Trading forest carbon

    EPA Science Inventory

    The nature of carbon in forests is discussed from the perspective of carbon trading. Carbon inventories, specifically in the area of land use and forestry are reviewed for the Pacific Northwest. Carbon turnover in forests is discussed as it relates to carbon sequestration. Scient...

  17. [Attributes of forest infrastructure].

    PubMed

    Gao, Jun-kai; Jin, Ying-shan

    2007-06-01

    This paper discussed the origin and evolution of the conception of ecological infrastructure, the understanding of international communities about the functions of forest, the important roles of forest in China' s economic development and ecological security, and the situations and challenges to the ongoing forestry ecological restoration programs. It was suggested that forest should be defined as an essential infrastructure for national economic and social development in a modern society. The critical functions of forest infrastructure played in the transition of forestry ecological development were emphasized. Based on the synthesis of forest ecosystem features, it was considered that the attributes of forest infrastructure are distinctive, due to the fact that it is constructed by living biological material and diversified in ownership. The forestry ecological restoration program should not only follow the basic principles of infrastructural construction, but also take the special characteristics of forests into consideration in studying the managerial system of the programs. Some suggestions for the ongoing programs were put forward: 1) developing a modern concept of ecosystem where man and nature in harmony is the core, 2) formulating long-term stable investments for forestry ecological restoration programs, 3) implementing forestry ecological restoration programs based on infrastructure construction principles, and 4) managing forests according to the principles of infrastructural construction management.

  18. Chisholm Forest Fire

    Atmospheric Science Data Center

    2013-04-17

    ... Larger Image A new look at smoke from the Chisholm forest fire, which ignited on May 23, 2001 about 160 kilometers north of ... in detail by M. Fromm and R. Servranckx, "Transport of forest fire smoke above the tropopause by supercell convection", Geophys. Res. ...

  19. 76 FR 65681 - Black Hills National Forest, Mystic Ranger District, South Dakota, Calumet Project Area

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... an existing insect and disease epidemic (mountain pine beetle), creating a landscape condition more... to ecosystem components including forest resources, from the existing insect and disease (mountain... focused on reducing insects or disease on public and adjacent private lands, and reducing the...

  20. 78 FR 34669 - Incidental Take Permit and Environmental Assessment for Forest Management Activities, Southern...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... management activities by Potlatch Forest Holdings, Inc. (Applicant) that would take the endangered red... harvesting activities on Potlatch lands in Arkansas; and provisioning and maintenance activities associated... managed under a separate HCP adjacent to Felsenthal NWR, Potlatch lands, and up to eight isolated...

  1. Quantifying canopy complexity and effects on productivity and resilience in late-successional hemlock-hardwood forests.

    PubMed

    Fahey, Robert T; Fotis, Alexander T; Woods, Kerry D

    2015-04-01

    The regrowing forests of eastern North America have been an important global C sink over the past 100+ years, but many are now transitioning into late succession. The consequences of this transition are unclear due to uncertainty around the C dynamics of old- growth forests. Canopy structural complexity (CSC) has been shown to be an important source of variability in C dynamics in younger forests (e.g., in productivity and resilience to disturbance), but its role in late-successional forests has not been widely addressed. We investigated patterns of CSC in two old-growth forest landscapes in the Upper Peninsula of Michigan, USA, to assess factors associated with CSC and its influence on productivity and disturbance resilience (to moderate-severity windstorm). CSC was quantified using a portable below-canopy LiDAR (PCL) system in 65 plots that also had long-term (50-70+ years). inventory data, which were used to quantify aboveground net primary productivity (ANPP), disturbance history, and stand characteristics. We found high and variable CSC relative to younger forests across a suite of PCL-derived metrics. Variation in CSC was driven by species composition and size structure, rather than disturbance history or site characteristics. Recent moderate severity wind disturbance decreased plot-scale CSC, but increased stand-scale variation in CSC. The strong positive correlation between CSC and productivity illustrated in younger forests was not present in undisturbed portions of these late-successional ecosystems. Moderate severity disturbance appeared to reestablish the positive link between CSC and productivity, but this relationship was scale and severity dependent. A positive CSC-productivity relationship was evident at the plot scale with low-severity, dispersed disturbance, but only at a patch scale in more severely disturbed areas. CSC does not appear to strongly correlate With variation in productivity in undisturbed old-growth forests, but may play a very

  2. Dynamics of cover, UV-protective pigments, and quantum yield in biological soil crust communities of an undisturbed Mojave Desert shrubland

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Smith, S.D.

    2007-01-01

    Biological soil crusts are an integral part of dryland ecosystems. We monitored the cover of lichens and mosses, cyanobacterial biomass, concentrations of UV-protective pigments in both free-living and lichenized cyanobacteria, and quantum yield in the soil lichen species Collema in an undisturbed Mojave Desert shrubland. During our sampling time, the site received historically high and low levels of precipitation, whereas temperatures were close to normal. Lichen cover, dominated by Collema tenax and C. coccophorum, and moss cover, dominated by Syntrichia caninervis, responded to both increases and decreases in precipitation. This finding for Collema spp. at a hot Mojave Desert site is in contrast to a similar study conducted at a cool desert site on the Colorado Plateau in SE Utah, USA, where Collema spp. cover dropped in response to elevated temperatures, but did not respond to changes in rainfall. The concentrations of UV-protective pigments in free-living cyanobacteria at the Mojave Desert site were also strongly and positively related to rainfall received between sampling times (R2 values ranged from 0.78 to 0.99). However, pigment levels in the lichenized cyanobacteria showed little correlation with rainfall. Quantum yield in Collema spp. was closely correlated with rainfall. Climate models in this region predict a 3.5-4.0 ??C rise in temperature and a 15-20% decline in winter precipitation by 2099. Based on our data, this rise in temperature is unlikely to have a strong effect on the dominant species of the soil crusts. However, the predicted drop in precipitation will likely lead to a decrease in soil lichen and moss cover, and high stress or mortality in soil cyanobacteria as levels of UV-protective pigments decline. In addition, surface-disturbing activities (e.g., recreation, military activities, fire) are rapidly increasing in the Mojave Desert, and these disturbances quickly remove soil lichens and mosses. These stresses combined are likely to lead to

  3. Landsat-faciliated vegetation classification of the Kenai National Wildlife Refuge and adjacent areas, Alaska

    USGS Publications Warehouse

    Talbot, S. S.; Shasby, M.B.; Bailey, T.N.

    1985-01-01

    A Landsat-based vegetation map was prepared for Kenai National Wildlife Refuge and adjacent lands, 2 million and 2.5 million acres respectively. The refuge lies within the middle boreal sub zone of south central Alaska. Seven major classes and sixteen subclasses were recognized: forest (closed needleleaf, needleleaf woodland, mixed); deciduous scrub (lowland and montane, subalpine); dwarf scrub (dwarf shrub tundra, lichen tundra, dwarf shrub and lichen tundra, dwarf shrub peatland, string bog/wetlands); herbaceous (graminoid meadows and marshes); scarcely vegetated areas ; water (clear, moderately turbid, highly turbid); and glaciers. The methodology employed a cluster-block technique. Sample areas were described based on a combination of helicopter-ground survey, aerial photo interpretation, and digital Landsat data. Major steps in the Landsat analysis involved: preprocessing (geometric connection), spectral class labeling of sample areas, derivation of statistical parameters for spectral classes, preliminary classification of the entree study area using a maximum-likelihood algorithm, and final classification through ancillary information such as digital elevation data. The vegetation map (scale 1:250,000) was a pioneering effort since there were no intermediate-sclae maps of the area. Representative of distinctive regional patterns, the map was suitable for use in comprehensive conservation planning and wildlife management.

  4. Late Quaternary history of the southwestern St. Lawrence Lowlands and adjacent Adirondack Highlands

    SciTech Connect

    Pair, D.L. . Dept. of Geology)

    1993-03-01

    The reconstruction of Late Wisconsinan ice retreat, proglacial lakes, and Champlain Sea history from the northwest Adirondack slope and adjacent St. Lawrence Lowlands is critical to the synthesis of a regional picture of deglacial events in the eastern Great Lakes region. Unfortunately, these same areas are well known for their limited exposures, landforms covered by thick forest, large tracts of land inaccessible to detailed field mapping, and the overall paucity of glacial materials preserved on upland surfaces. Despite these limitations, a model which utilizes multiple and field-truthed evidence has been used to designate areas where ice border deposits indicate a substantial recessional position. It employs the following criteria in this analysis: sedimentology and morphostratigraphy of morainal landform segments and related sediments; orientation and continuity of ice border drainage channels; and the relationship of ice borders and drainage systems to well documented local and regional water bodies which accompanied ice retreat. The results of this approach have provided a unique regional picture of deglaciation. Despite the inherent limitations of working in upland areas to reconstruct glacial events, detailed morphostratigraphic correlations based on multiple lines of evidence can yield important information. The positions of five former ice borders have been reconstructed from the available data. These ice margins correspond closely with those documented previously by others adjoining areas. This type of study, utilizing multiple and field-truthed lines of evidence, constitutes a tangible step towards understanding the nature and history of ice retreat along this portion of the Laurentide Ice Sheet.

  5. Ecohydrology of adjacent sagebrush and lodgepole pine ecosystems: the consequences of climate change and disturbance

    USGS Publications Warehouse

    Bradford, John B.; Schlaepfer, Daniel R.; Lauenroth, William K.

    2014-01-01

    Sagebrush steppe and lodgepole pine forests are two of the most widespread vegetation types in the western United States and they play crucial roles in the hydrologic cycle of these water-limited regions. We used a process-based ecosystem water model to characterize the potential impact of climate change and disturbance (wildfire and beetle mortality) on water cycling in adjacent sagebrush and lodgepole pine ecosystems. Despite similar climatic and topographic conditions between these ecosystems at the sites examined, lodgepole pine, and sagebrush exhibited consistent differences in water balance, notably more evaporation and drier summer soils in the sagebrush and greater transpiration and less water yield in lodgepole pine. Canopy disturbances (either fire or beetle) have dramatic impacts on water balance and availability: reducing transpiration while increasing evaporation and water yield. Results suggest that climate change may reduce snowpack, increase evaporation and transpiration, and lengthen the duration of dry soil conditions in the summer, but may have uncertain effects on drainage. Changes in the distribution of sagebrush and lodgepole pine ecosystems as a consequence of climate change and/or altered disturbance regimes will likely alter ecosystem water balance.

  6. Species richness and relative species abundance of Nymphalidae (Lepidoptera) in three forests with different perturbations in the North-Central Caribbean of Costa Rica.

    PubMed

    Stephen, Carolyn; Sánchez, Ragde

    2014-09-01

    Measurements of species richness and species abundance can have important implications for regulations and conservation. This study investigated species richness and abundance of butterflies in the family Nymphalidae at undisturbed, and disturbed habitats in Tirimbina Biological Reserve and Nogal Private Reserve, Sarapiquí, Costa Rica. Traps baited with rotten banana were placed in the canopy and the understory of three habitats: within mature forest, at a river/forest border, and at a banana plantation/forest border. In total, 71 species and 487 individuals were caught and identified during May and June 2011 and May 2013. Species richness and species abundance were found to increase significantly at perturbed habitats (p < 0.0001, p < 0.0001, respectively). The edge effect, in which species richness and abundance increase due to greater complementary resources from different habitats, could be one possible explanation for increased species richness and abundance.

  7. Cultural Resources Inventory of Lands Adjacent to Lake Winnibigoshish,

    DTIC Science & Technology

    1977-06-01

    to be replaced by a [- Pinus banksiana (jack pine) dominated forest (probably an eastern immigrant) I C (McAndrews, personal communication). This...Winnibigoshish area, Ilying between these two regions, but close to the eastern edge of the oak- savannah penetration, may offer data on the interaction between...is primarily a lakeshore oriented culture, and shows affinities (though very dilute) with the Havanna Hopewellian cultures of Illinois, eastern Iowa

  8. Net primary production of a temperate deciduous forest exhibits a threshold response to increasing disturbance severity.

    PubMed

    Stuart-Haëntjens, Ellen J; Curtis, Peter S; Fahey, Robert T; Vogel, Christoph S; Gough, Christopher M

    2015-09-01

    The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C storage. Disturbances to forests occur along a continuum of severity, from low-intensity disturbance causing the mortality or defoliation of only a subset of trees to severe stand- replacing disturbance that kills all trees; yet considerable uncertainty remains in how forest production changes across gradients of disturbance intensity. We used a gradient of tree mortality in an upper Great Lakes forest ecosystem to: (1) quantify how aboveground wood net primary production (ANPP,) responds to a range of disturbance severities; and (2) identify mechanisms supporting ANPPw resistance or resilience following moderate disturbance. We found that ANPPw declined nonlinearly with rising disturbance severity, remaining stable until >60% of the total tree basal area senesced. As upper canopy openness increased from disturbance, greater light availability to the subcanopy enhanced the leaf-level photosynthesis and growth of this formerly light-limited canopy stratum, compensating for upper canopy production losses and a reduction in total leaf area index (LAI). As a result, whole-ecosystem production efficiency (ANPPw/LAI) increased with rising disturbance severity, except in plots beyond the disturbance threshold. These findings provide a mechanistic explanation for a nonlinear relationship between ANPPw, and disturbance severity, in which the physiological and growth enhancement of undisturbed vegetation is proportional to the level of disturbance until a threshold is exceeded. Our results have important ecological and management implications, demonstrating that in some ecosystems moderate levels of disturbance minimally alter forest production.

  9. Examination of Tropical Forest Structure Using Field Data and High Spatial Resolution Image Data

    NASA Astrophysics Data System (ADS)

    Palace, M.; Keller, M.; Hunter, M.; Braswell, B.; Hagen, S.; Lefsky, M.

    2007-12-01

    Structural properties of tropical forests are an important component in ecological studies, yet they are difficult to quantify. Remote sensing of forest canopy structure estimation has greatly advanced to due the aid of high resolution satellite images. Field based methods of canopy structure have also improved due to the involvement of handheld laser range finders, which aid in gauging height, width, and depth of tree canopies. Using a handheld laser rangefinder we estimated canopy depth and generated canopy profiles from this data. Previously, we developed a crown characterization algorithm that uses high resolution satellite image data and have applied this algorithm in undisturbed tropical forests with good results. In this work we have further developed the algorithm to examine canopy depth using two allometric equations, developed from field data, that relate crown width to the top of the canopy and bottom of the canopy. Modification of our original algorithm also involved the incorporation of site specific allometric equations developed from field based measurements. Automated analysis of IKONOS imagery was used to estimate the distribution of canopy elements at various heights and their spatial locations. A comparison between the field based data and the estimates derived from remotely sensed images was conducted at four sites throughout Amazonia. We further compared our estimates of canopy structure with results from large footprint LIDAR data from GLAS. Ability to estimate canopy profiles and forest structural properties in vast areas of the Brazilian Amazon using high resolution imagery will help us to understand the regional carbon balance.

  10. 78 FR 73819 - Forest Resource Coordinating Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of...-18, 2013 meeting of the Forest Resource Coordinating Committee due to the Government partial shutdown... INFORMATION CONTACT: Maya Solomon, Forest Resource Coordinating Committee Program Coordinator; by phone...

  11. Impact of adjacent land use on coastal wetland sediments.

    PubMed

    Karstens, Svenja; Buczko, Uwe; Jurasinski, Gerald; Peticzka, Robert; Glatzel, Stephan

    2016-04-15

    Coastal wetlands link terrestrial with marine ecosystems and are influenced from both land and sea. Therefore, they are ecotones with strong biogeochemical gradients. We analyzed sediment characteristics including macronutrients (C, N, P, K, Mg, Ca, S) and heavy metals (Mn, Fe, Cu, Zn, Al, Co, Cr, Ni) of two coastal wetlands dominated by Phragmites australis at the Darss-Zingst Bodden Chain, a lagoon system at the Southern Baltic Sea, to identify the impact of adjacent land use and to distinguish between influences from land or sea. In the wetland directly adjacent to cropland (study site Dabitz) heavy metal concentrations were significantly elevated. Fertilizer application led to heavy metal accumulation in the sediments of the adjacent wetland zones. In contrast, at the other study site (Michaelsdorf), where the hinterland has been used as pasture, heavy metal concentrations were low. While the amount of macronutrients was also influenced by vegetation characteristics (e.g. carbon) or water chemistry (e.g. sulfate), the accumulation of heavy metals is regarded as purely anthropogenic influence. A principal component analysis (PCA) based on the sediment data showed that the wetland fringes of the two study sites are not distinguishable, neither in their macronutrient status nor in their concentrations of heavy metals, whereas the interior zones exhibit large differences in terms of heavy metal concentrations. This suggests that seaside influences are minor compared to influences from land. Altogether, heavy metal concentrations were still below national precautionary and action values. However, if we regard the macronutrient and heavy metal concentrations in the wetland fringes as the natural background values, an accumulation of trace elements from agricultural production in the hinterland is apparent. Thus, coastal wetlands bordering croplands may function as effective pollutant buffers today, but the future development has to be monitored closely to avoid

  12. Adjacent segment disease and C-ADR: promises fulfilled?

    PubMed Central

    Riew, K Daniel; Schenk-Kisser, Jeannette M.; Skelly, Andrea C.

    2012-01-01

    Study design: Systematic review. Clinical question: Do the rates and timing of adjacent segment disease (ASD) differ between cervical total disc arthroplasty (C-ADR) and anterior cervical discectomy and fusion (ACDF) in patients treated for cervical degenerative disc disease? Methods: A systematic search of MEDLINE/PubMed and bibliographies of key articles was done to identify studies with long-term follow-up for symptomatic and/or radiographic ASD comparing C-ADR with fusion for degenerative disc disease of the cervical spine. The focus was on studies with longer follow-up (48–60 months) of primary US Food and Drug Administration trials of Prestige ST, Prodisc-C, and Bryan devices as available. Trials of other discs with a minimum of 24 months follow-up were considered for inclusion. Studies evaluating lordosis/angle changes at adjacent segments and case series were excluded. Results: From 14 citations identified, four reports from three randomized controlled trials and four nonrandomized studies are summarized. Risk differences between C-ADR and ACF for symptomatic ASD were 1.5%–2.3% and were not significant across RCT reports. Time to development of ASD did not significantly differ between treatments. Rates of radiographic ASD were variable. No meaningful comparison of ASD rates based on disc design was possible. No statistical differences in adjacent segment range of motion were noted between treatment groups. Conclusion: Our analysis reveals that, to date, there is no evidence that arthroplasty decreases ASD compared with ACDF; the promise of arthroplasty decreasing ASD has not been fulfilled. PMID:23236312

  13. Metagenomic assessment of the potential microbial nitrogen pathways in the rhizosphere of a mediterranean forest after a wildfire.

    PubMed

    Cobo-Díaz, José F; Fernández-González, Antonio J; Villadas, Pablo J; Robles, Ana B; Toro, Nicolás; Fernández-López, Manuel

    2015-05-01

    Wildfires are frequent in the forests of the Mediterranean Basin and have greatly influenced this ecosystem. Changes to the physical and chemical properties of the soil, due to fire and post-fire conditions, result in alterations of both the bacterial communities and the nitrogen cycle. We explored the effects of a holm oak forest wildfire on the rhizospheric bacterial communities involved in the nitrogen cycle. Metagenomic data of the genes involved in the nitrogen cycle showed that both the undisturbed and burned rhizospheres had a conservative nitrogen cycle with a larger number of sequences related to the nitrogen incorporation pathways and a lower number for nitrogen output. However, the burned rhizosphere showed a statistically significant increase in the number of sequences for nitrogen incorporation (allantoin utilization and nitrogen fixation) and a significantly lower number of sequences for denitrification and dissimilatory nitrite reductase subsystems, possibly in order to compensate for nitrogen loss from the soil after burning. The genetic potential for nitrogen incorporation into the ecosystem was assessed through the diversity of the nitrogenase reductase enzyme, which is encoded by the nifH gene. We found that nifH gene diversity and richness were lower in burned than in undisturbed rhizospheric soils. The structure of the bacterial communities involved in the nitrogen cycle showed a statistically significant increase of Actinobacteria and Firmicutes phyla after the wildfire. Both approaches showed the important role of gram-positive bacteria in the ecosystem after a wildfire.

  14. CLOUD PEAK PRIMITIVE AREA AND ADJACENT AREAS, WYOMING.

    USGS Publications Warehouse

    Kiilsgaard, Thor H.; Patten, Lowell L.

    1984-01-01

    The results of a mineral survey of the Cloud Peak Primitive Area and adjacent areas in Wyoming indicated little promise for the occurrence of mineral resources. There are some prospect workings, particularly in the northern part of the area, but in none of them were there indications that ore had been mined. Samples from the workings, from nearby rocks and sediments from streams that drain the area did not yield any metal values of significance. The crystalline rocks that underlie the area do not contain oil and gas or coal, products that are extracted from the younger rocks that underlie basins on both sides of the study area.

  15. Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters.

    PubMed

    Engl, Oliver D; Fritz, Sven P; Wennemers, Helma

    2015-07-06

    Oxindoles with adjacent tetrasubstituted stereocenters were obtained in high yields and stereoselectivities by organocatalyzed conjugate addition reactions of monothiomalonates (MTMs) to isatin-derived N-Cbz ketimines. The method requires only a low catalyst loading (2 mol %) and proceeds under mild reaction conditions. Both enantiomers are accessible in good yields and excellent stereoselectivities by using either Takemoto's catalyst or a cinchona alkaloid derivative. The synthetic methodology allowed establishment of a straightforward route to derivatives of the gastrin/cholecystokinin-B receptor antagonist AG-041R.

  16. Interaction of Cracks Between Two Adjacent Indents in Glass

    NASA Technical Reports Server (NTRS)

    Choi, S. R.; Salem, J. A.

    1993-01-01

    Experimental observations of the interaction behavior of cracks between two adjacent indents were made using an indentation technique in soda-lime glass. It was specifically demonstrated how one indent crack initiates and propagates in the vicinity of another indent crack. Several types of crack interactions were examined by changing the orientation and distance of one indent relative to the other. It was found that the residual stress field produced by elastic/plastic indentation has a significant influence on controlling the mode of crack interaction. The interaction of an indent crack with a free surface was also investigated for glass and ceramic specimens.

  17. Astronaut Charles Duke stands at rock adjacent to 'House Rock'

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Astronaut Charles M. Duke Jr., Apollo 16 lunar module pilot, stands at a rock adjacent (south) to the huge 'House Rock' (barely out of view at right edge). Note shadow at extreme right center where the two moon-exploring crewmen of the mission sampled what they referred to as the 'eastwest split of House Rock' or the open space between this rock and 'House Rock'. Duke has a sample bag in his hand, and a lunar surface rake leans against the large boulder.

  18. Empires and percolation: stochastic merging of adjacent regions

    NASA Astrophysics Data System (ADS)

    Aldous, D. J.; Ong, J. R.; Zhou, W.

    2010-01-01

    We introduce a stochastic model in which adjacent planar regions A, B merge stochastically at some rate λ(A, B) and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on λ for this hegemony property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case λ(A, B) ≡ 1. For this case, a non-rigorous analytic argument and simulations suggest hegemony.

  19. The Influence of Atmospheric CO2 Concentration and Climate Variability on Amazon Tropical Forest

    NASA Astrophysics Data System (ADS)

    Castanho, A. D. D. A.; Galbraith, D.; Zhang, K.; Coe, M. T.; Costa, M. H.; Moorcroft, P. R.

    2014-12-01

    Tropical forests are important regulators of atmospheric CO2 concentration and any change in tropical forest C balance will directly affect global climate. Long term studies from undisturbed old-growth forest monitoring sites distributed across Amazonia have presented an overall increase in aboveground biomass in the last decades, and the increase in atmospheric CO2 concentrations is considered the main driver for this observed carbon sink. The main goal of this work was to use simulations from dynamic global vegetation models (DGVM) to explore how much of the observed historical (1970-2008) increase in biomass in undisturbed tropical forest in Amazonia could be attributed to the CO2 fertilization effect or associated to climate change. We compared simulated biomass and productivity from three DGVMs (IBIS, ED2 and JULES) with observations from forest plots (RAINFOR). The analyses helped clarify the variability of historical and potential future simulations.The analyses showed that models shared similar results and deficiencies. The three models represented the two major model types: conventional dynamic global vegetation models that simulate community dynamics and competition between plant functional types (PFTs) using an aggregated 'big-leaf' representation (IBIS and Jules), and a size-and-age structured terrestrial ecosystem model that captures individual scale dynamics and competition (ED2). In general, the ED2 model results were more sensitive to climate, but all models greatly underestimate the impact of extreme climatic events (e.g. drought) compared to field data.All the DGVM's studied tend to simulate the average biomass well and to overestimate productivity of vegetation under current conditions. All the models presented very low spatial variability compared to field observation. The lack of spatial variability of biomass and productivity is attributed to the lack of nutrient and residence time spatial heterogeneity. All of the DGVMs results suggest that

  20. Forest structure in low-diversity tropical forests: a study of Hawaiian wet and dry forests.

    PubMed

    Ostertag, Rebecca; Inman-Narahari, Faith; Cordell, Susan; Giardina, Christian P; Sack, Lawren

    2014-01-01

    The potential influence of diversity on ecosystem structure and function remains a topic of significant debate, especially for tropical forests where diversity can range widely. We used Center for Tropical Forest Science (CTFS) methodology to establish forest dynamics plots in montane wet forest and lowland dry forest on Hawai'i Island. We compared the species diversity, tree density, basal area, biomass, and size class distributions between the two forest types. We then examined these variables across tropical forests within the CTFS network. Consistent with other island forests, the Hawai'i forests were characterized by low species richness and very high relative dominance. The two Hawai'i forests were floristically distinct, yet similar in species richness (15 vs. 21 species) and stem density (3078 vs. 3486/ha). While these forests were selected for their low invasive species cover relative to surrounding forests, both forests averaged 5->50% invasive species cover; ongoing removal will be necessary to reduce or prevent competitive impacts, especially from woody species. The montane wet forest had much larger trees, resulting in eightfold higher basal area and above-ground biomass. Across the CTFS network, the Hawaiian montane wet forest was similar to other tropical forests with respect to diameter distributions, density, and aboveground biomass, while the Hawai'i lowland dry forest was similar in density to tropical forests with much higher diversity. These findings suggest that forest structural variables can be similar across tropical forests independently of species richness. The inclusion of low-diversity Pacific Island forests in the CTFS network provides an ∼80-fold range in species richness (15-1182 species), six-fold variation in mean annual rainfall (835-5272 mm yr(-1)) and 1.8-fold variation in mean annual temperature (16.0-28.4°C). Thus, the Hawaiian forest plots expand the global forest plot network to enable testing of ecological theory for

  1. 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%

  2. Sustainable Management in Crop Monocultures: The Impact of Retaining Forest on Oil Palm Yield

    PubMed Central

    Edwards, Felicity A.; Edwards, David P.; Sloan, Sean; Hamer, Keith C.

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture. PMID:24638038

  3. Lithologic, structural, and geomorphic controls on ribbon forest patterns in a glaciated mountain environment

    NASA Astrophysics Data System (ADS)

    Butler, David R.; Malanson, George P.; Bekker, Matthew F.; Resler, Lynn M.

    2003-09-01

    So-called "ribbon forests" have been attributed to snowdrift patterns and fire history without reference to geomorphology [Vegetatio 19 (1969) 192.]. This paper illustrates how site conditions of geomorphology and geology explain the origin of ribbon forests. In Glacier National Park, MT (USA), regional tectonic uplift associated with the Laramide Orogeny produced structural features that amplify lithologic differences. Pleistocene glaciation scoured deeply along the strike of bedding planes, highlighting this pattern and in some cases producing fine-scale parallel finger lakes between forested ribbon strips. Twelve ribbon forest sites on both sides of the Continental Divide were closely studied on stereoscopic aerial photographs, and several of these sites were examined in the field or from helicopter overflights. In all cases, geologic and geomorphic conditions explain the location and distribution of the ribbon forests. Change-detection of the distribution of trees versus nontree-covered surfaces in an area of ribbon forest on Flattop Mountain, a complex uplifted synclinal structure, was undertaken using panchromatic, low-altitude aerial photographs from 1966 to 1991. Areas changed from forest to meadow and from meadow to forest in roughly equal amounts in a generally random spatial pattern. No evidence was seen to suggest that the creation of one ribbon eventually created another downwind, as suggested by Billings. Aerial photograph interpretation, field examination and soils analyses of forest ribbons and adjacent unforested meadows clearly illustrated that trees occupy higher, parallel to subparallel, well-drained sites where the spatial pattern is in turn a distinct reflection of the spatial pattern of structure and stratigraphy. Meadows occupy topographically lower positions between ridges where erosion along bedding plane strike was concentrated. Topography sets conditions that allow tree growth in certain locations while precluding it in immediately

  4. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    PubMed

    Edwards, Felicity A; Edwards, David P; Sloan, Sean; Hamer, Keith C

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture.

  5. Forest pathology in Hawaii

    USGS Publications Warehouse

    Gardner, D.E.

    2003-01-01

    Native Hawaiian forests are characterised by a high degree of endemism, including pathogens as well as their hosts. With the exceptions of koa (Acacia koa Gray), possibly maile (Alyxia oliviformis Gaud.), and, in the past, sandalwood (Santalum spp.), forest species are of little commercial value. On the other hand, these forests are immensely important from a cultural, ecological, and evolutionary standpoint. Forest disease research was lacking during the mid-twentieth century, but increased markedly with the recognition of ohia (Metrosideros polymorpha Gaud.) decline in the 1970s. Because many pathogens are themselves endemic, or are assumed to be, having evolved with their hosts, research emphasis in natural areas is on understanding host-parasite interactions and evolutionary influences, rather than disease control. Aside from management of native forests, attempts at establishing a commercial forest industry have included importation of several species of pine, Araucaria, and Eucalyptus as timber crops, and of numerous ornamentals. Diseases of these species have been introduced with their hosts. The attacking of native species by introduced pathogens is problematic - for example, Armillaria mellea (Vahl ex Fr.) Que??l. on koa and mamane (Sophora chrysophylla (Salisb.) Seem.). Much work remains to be done in both native and commercial aspects of Hawaiian forest pathology.

  6. Urbanization impacts on mammals across urban-forest edges and a predictive model of edge effects.

    PubMed

    Villaseñor, Nélida R; Driscoll, Don A; Escobar, Martín A H; Gibbons, Philip; Lindenmayer, David B

    2014-01-01

    With accelerating rates of urbanization worldwide, a better understanding of ecological processes at the wildland-urban interface is critical to conserve biodiversity. We explored the effects of high and low-density housing developments on forest-dwelling mammals. Based on habitat characteristics, we expected a gradual decline in species abundance across forest-urban edges and an increased decline rate in higher contrast edges. We surveyed arboreal mammals in sites of high and low housing density along 600 m transects that spanned urban areas and areas turn on adjacent native forest. We also surveyed forest controls to test whether edge effects extended beyond our edge transects. We fitted models describing richness, total abundance and individual species abundance. Low-density housing developments provided suitable habitat for most arboreal mammals. In contrast, high-density housing developments had lower species richness, total abundance and individual species abundance, but supported the highest abundances of an urban adapter (Trichosurus vulpecula). We did not find the predicted gradual decline in species abundance. Of four species analysed, three exhibited no response to the proximity of urban boundaries, but spilled over into adjacent urban habitat to differing extents. One species (Petaurus australis) had an extended negative response to urban boundaries, suggesting that urban development has impacts beyond 300 m into adjacent forest. Our empirical work demonstrates that high-density housing developments have negative effects on both community and species level responses, except for one urban adapter. We developed a new predictive model of edge effects based on our results and the literature. To predict animal responses across edges, our framework integrates for first time: (1) habitat quality/preference, (2) species response with the proximity to the adjacent habitat, and (3) spillover extent/sensitivity to adjacent habitat boundaries. This framework will

  7. Soil organic carbon dynamics in the forest-grassland limit.

    NASA Astrophysics Data System (ADS)

    Díaz-Pinés, Eugenio; Vázquez, Eduardo; Ortiz, Carlos; Schindlbacher, Andreas; Jandl, Robert; Kiese, Ralf; Butterbach-Bahl, Klaus; Benito, Marta; Rubio, Agustin

    2014-05-01

    An upward shift of the treeline at the extent of former grasslands has been observed in the last decades in several regions along the world. Implications of the land use change from grasslands to forests are not clear yet in regard to soil organic carbon stocks, greenhouse gas fluxes and composition of the soil organic matter. In order to investigate the consequences of forest expansion at the regional scale, an extensive grassland—forest comparison was conducted at the altitudinal limit of the forest. We considered two contrasting geographical areas: one Mediterranean -The Sistema Central in Spain- and one temperate area -the Austrian Alps-. Ten and seven sites were investigated, respectively. At each of the sites, the forest floor and the topsoil was sampled in grasslands and adjacent coniferous forest areas. Mineral soils were incubated for 6 months in the laboratory under standardized conditions and both bulk concentration and the isotopic signature of soil organic carbon and nitrogen were determined across the study sites. Grasslands were not consistently different from forests in terms of soil organic carbon concentrations and cumulative soil carbon dioxide effluxes. However, soil C:N ratio was significantly narrower in grasslands than in forests, and this results was consistent for both Spanish and Austrian sites. Isotopic signature of C and N resulted to be significantly different between grasslands and forests for Spanish soils, only, suggesting a combined influence of land use change and climate. In Spain, grasslands soils were enriched in 15N but depleted in 13C as compared to forests soils. Interestingly, mean temperature negatively influenced C concentrations in Spanish grasslands, but had no clear effect on forests. Our results did not show a clear trend of net soil organic carbon gain or loss due to forest expansion, but rather a change in the characteristics of the soil mineralization conditions after vegetation shifted. Changes in transformation

  8. Trophic structure stability and extinction dynamics of beetles (Coleoptera) in tropical forest fragments

    PubMed Central

    Didham, R. K.

    1998-01-01

    higher probabilities of local extinction following fragmentation. The majority of these species were predators; 42% of all abundant predator species were significantly more likely to be absent from samples in forest fragments than in undisturbed forest. These figures are regarded as minimum estimates for the entire beetle assemblage because rarer species will inevitably have higher extinction probabilities. Absolute loss of biodiversity will affect ecosystem process rates, but the differential loss of species from trophic groups will have an even greater destabilizing effect on food web structure and ecosystem function.

  9. Stress Wave Interaction Between Two Adjacent Blast Holes

    NASA Astrophysics Data System (ADS)

    Yi, Changping; Johansson, Daniel; Nyberg, Ulf; Beyglou, Ali

    2016-05-01

    Rock fragmentation by blasting is determined by the level and state of stress in the rock mass subjected to blasting. With the application of electronic detonators, some researchers stated that it is possible to achieve improved fragmentation through stress wave superposition with very short delay times. This hypothesis was studied through theoretical analysis in the paper. First, the stress in rock mass induced by a single-hole shot was analyzed with the assumptions of infinite velocity of detonation and infinite charge length. Based on the stress analysis of a single-hole shot, the stress history and tensile stress distribution between two adjacent holes were presented for cases of simultaneous initiation and 1 ms delayed initiation via stress superposition. The results indicated that the stress wave interaction is local around the collision point. Then, the tensile stress distribution at the extended line of two adjacent blast holes was analyzed for a case of 2 ms delay. The analytical results showed that the tensile stress on the extended line increases due to the stress wave superposition under the assumption that the influence of neighboring blast hole on the stress wave propagation can be neglected. However, the numerical results indicated that this assumption is unreasonable and yields contrary results. The feasibility of improving fragmentation via stress wave interaction with precise initiation was also discussed. The analysis in this paper does not support that the interaction of stress waves improves the fragmentation.

  10. Coexistence Analysis of Adjacent Long Term Evolution (LTE) Systems

    SciTech Connect

    Aulama, Mohannad M.; Olama, Mohammed M

    2013-01-01

    As the licensing and deployment of Long term evolution (LTE) systems are ramping up, the study of coexistence of LTE systems is an essential topic in civil and military applications. In this paper, we present a coexistence study of adjacent LTE systems aiming at evaluating the effect of inter-system interference on system capacity and performance as a function of some of the most common mitigation techniques: frequency guard band, base station (BS) antenna coupling loss, and user equipment (UE) antenna spacing. A system model is constructed for two collocated macro LTE networks. The developed model takes into consideration the RF propagation environment, power control scheme, and adjacent channel interference. Coexistence studies are performed for a different combination of time/frequency division duplex (TDD/FDD) systems under three different guard-bands of 0MHz, 5MHz, and 10MHz. Numerical results are presented to advice the minimum frequency guard band, BS coupling loss, and UE antenna isolation required for a healthy system operation.

  11. A Long Term View of Forest Response to Environmental Change: 25 Years of Studying Harvard Forest

    NASA Astrophysics Data System (ADS)

    Munger, J. W.; Wofsy, S. C.; Lindaas, J.; David, F.; David, O.

    2014-12-01

    Forests influence the budgets of greenhouse gases, and understanding how they will respond to environmental change is critical to accurately predicting future GHG trends. The time scale for climate change is long and forest growth is slow, thus very long measurement periods are required to observe meaningful forest response. We established an eddy flux tower within a mixed forest stand dominated by red oak and red maple at the Harvard Forest LTER site in 1989 where CO2, H2O and energy fluxes together with meteorological observations have been measured continuously. An array of plots for biometric measurements was established in 1993. Flux measurement at an adjacent hemlock stand began in 2000. Records of land use and disturbance and vegetation plot data extend back to 1907. The combined suite of measurements merges observations of instantaneous ecosystem responses to environmental forcing with details of vegetation dynamics and forest growth that represent the emergent properties relevant to long-term ecosystem change. Both the deciduous stand and hemlock stand are accumulating biomass. Each has added over 20 Mg-C ha-1 as woody biomass in trees >10cm dbh since 1990, even though the hemlock stand is older. Net carbon exchange shows enhanced uptake in early spring and late fall months in response to warmer temperatures and likely an increase in evergreen foliage at the deciduous site. Net carbon uptake efficiency at the deciduous stand has increased over time as well as indicated by peak NEE under optimum light conditions. The trend is only partly explained by variation in mean leaf area index and cannot be directly attributed to climate response. The combination of longer growing season and increased uptake efficiency yields a general trend of increasing annual NEE (Fig. 1). However, significant excursions in the trend highlight the sensitivity of forest carbon stocks. The pulse of high annual carbon uptake (peak 6 Mg-C ha-1y-1 in 2008) from 2000-2008 is only

  12. Phylobetadiversity among Forest Types in the Brazilian Atlantic Forest Complex

    PubMed Central

    Duarte, Leandro Da Silva; Bergamin, Rodrigo Scarton; Marcilio-Silva, Vinícius; Seger, Guilherme Dubal Dos Santos; Marques, Márcia Cristina Mendes

    2014-01-01

    Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao’s H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups

  13. Carbon pool densities and a first estimate of the total carbon pool in the Mongolian forest-steppe.

    PubMed

    Dulamsuren, Choimaa; Klinge, Michael; Degener, Jan; Khishigjargal, Mookhor; Chenlemuge, Tselmeg; Bat-Enerel, Banzragch; Yeruult, Yolk; Saindovdon, Davaadorj; Ganbaatar, Kherlenchimeg; Tsogtbaatar, Jamsran; Leuschner, Christoph; Hauck, Markus

    2016-02-01

    The boreal forest biome represents one of the most important terrestrial carbon stores, which gave reason to intensive research on carbon stock densities. However, such an analysis does not yet exist for the southernmost Eurosiberian boreal forests in Inner Asia. Most of these forests are located in the Mongolian forest-steppe, which is largely dominated by Larix sibirica. We quantified the carbon stock density and total carbon pool of Mongolia's boreal forests and adjacent grasslands and draw conclusions on possible future change. Mean aboveground carbon stock density in the interior of L. sibirica forests was 66 Mg C ha(-1) , which is in the upper range of values reported from boreal forests and probably due to the comparably long growing season. The density of soil organic carbon (SOC, 108 Mg C ha(-1) ) and total belowground carbon density (149 Mg C ha(-1) ) are at the lower end of the range known from boreal forests, which might be the result of higher soil temperatures and a thinner permafrost layer than in the central and northern boreal forest belt. Land use effects are especially relevant at forest edges, where mean carbon stock density was 188 Mg C ha(-1) , compared with 215 Mg C ha(-1) in the forest interior. Carbon stock density in grasslands was 144 Mg C ha(-1) . Analysis of satellite imagery of the highly fragmented forest area in the forest-steppe zone showed that Mongolia's total boreal forest area is currently 73 818 km(2) , and 22% of this area refers to forest edges (defined as the first 30 m from the edge). The total forest carbon pool of Mongolia was estimated at ~ 1.5-1.7 Pg C, a value which is likely to decrease in future with increasing deforestation and fire frequency, and global warming.

  14. Using Our National Forests Wisely.

    ERIC Educational Resources Information Center

    Feuchter, Roy

    1987-01-01

    Lists nine steps camps can follow to insure successful use of national forests. Steps are identifying national forest resources; matching expectations with the right setting; using recreation opportunity guides; planning for safety; practicing forest etiquette; practicing fire prevention; knowing the forest environment; participating in volunteer…

  15. 78 FR 23903 - Forest Service

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... Forest Service Dixie Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting... recommendations to the Forest Service concerning projects and funding consistent with Title II of the Act. The meeting is open to the public. The purpose of the meeting is to review proposals for forest projects...

  16. Water quality and fish dynamics in forested wetlands associated with an oxbow lake

    USGS Publications Warehouse

    Andrews, Caroline S.; Miranda, Leandro E.; Kroger, Robert

    2015-01-01

    Forested wetlands represent some of the most distinct environments in the Lower Mississippi Alluvial Valley. Depending on season, water in forested wetlands can be warm, stagnant, and oxygen-depleted, yet may support high fish diversity. Fish assemblages in forested wetlands are not well studied because of difficulties in sampling heavily structured environments. During the April–July period, we surveyed and compared the water quality and assemblages of small fish in a margin wetland (forested fringe along a lake shore), contiguous wetland (forested wetland adjacent to a lake), and the open water of an oxbow lake. Dissolved-oxygen levels measured hourly 0.5 m below the surface were higher in the open water than in either of the forested wetlands. Despite reduced water quality, fish-species richness and catch rates estimated with light traps were greater in the forested wetlands than in the open water. The forested wetlands supported large numbers of fish and unique fish assemblages that included some rare species, likely because of their structural complexity. Programs developed to refine agricultural practices, preserve riparian zones, and restore lakes should include guidance to protect and reestablish forested wetlands.

  17. Emissions of N2O from tropical forest soils - Response to fertilization with NH4(+), NO3(-), and PO4(3-)

    NASA Technical Reports Server (NTRS)

    Keller, M.; Kaplan, W. A.; Wofsy, S. C.; Da Costa, Jose Maria

    1988-01-01

    Undisturbed oxisols in a central Amazon tropical forest were fertilized with ammonium, nitrate, or phosphate. Enhanced emissions of N2O were observed for all treatments within one day of fertilization, with the response NO3(-) much greater than NH4(+) much greater than PO4(3-). Approximately, 0.5 percent of applied NO3(-) was converted to N2O within two weeks after application, with less than 0.1 percent of the NH4(+) converted to N2O. These experiments reveal a potentially large source of N2O from microbial reduction of NO3(-) in the clay soils of Amazonia.

  18. Microscale Pressure Fluctuations Within a Deciduous Forest

    NASA Astrophysics Data System (ADS)

    Sigmon, John Thomas

    Attempts to evaluate sources of errors in estimates of fluxes from forested surfaces have been thwarted by the lack of an accurate description of the nature of air flow within forest canopies. An important property of any boundary layer flow is the occurrence of pressure fluctuations at the boundary and within the flow. This study was designed to provide an understanding of the microscale pressure fluctuations within a forest canopy and the relationship between these fluctuations and the air flow within and above the forest canopy. Pressure fluctuations were measured using a method similar to that developed by J. A. Elliott in 1972. Measurements were taken at the ground and above a deciduous forest canopy. Time series, spectra, and cross-correlations were calculated under different canopy conditions, and relationships between surface pressure fluctuations and mean windspeeds were determined. Turbulent pressure fluctuations at the forest floor did not contain the higher frequencies found over smooth terrain and were continuously occurring at frequencies greater than 0.5 Hz. Somewhat higher frequencies and larger amplitudes occurred in the pressure fluctuations above the canopy after leaf emergence than at the surface. Horizontal length scales many times larger than the average spacing of the overstory trees were predominant. While both leaf emergence of flow-through from an adjacent field had an effect on the mean windspeed profiles, only the flow-through conditions had an effect on the relationship of mean windspeed above the canopy to pressure fluctuation variance at the surface. Pressure fluctuations at the surface appeared coupled at all times to those above the canopy and were directly related to windspeed above the canopy. Pressure eddies were advected downwind at speeds approximating the mean windspeed 6-8 meters above the canopy. Shapes of the pressure spectra were affected slightly by changes in windspeed, and comparisons of spectra above and below the

  19. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments

    PubMed Central

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A.; Habel, Jan C.

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species′ traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change. PMID:27855174

  20. From open to closed canopy: A century of change in Douglas-fir forest, Orcas Island, Washington

    USGS Publications Warehouse

    Peterson, D.L.; Hammer, R.D.

    2001-01-01

    During the past century, forest structure on south-facing slopes of Mount Constitution, Orcas Island, Washington, has changed from open-grown Douglas-fir (Pseudotsuga menziesii) mixed with prairie to primarily closed canopy forest. Density of open-grown Douglas-fir was approximately 7 stems/ha in the 19th century, while current density of trees in closed-canopy mature forest is 426 stems/ha. Trees occur at intermediate densities in areas of transition from savanna-like stands to closed canopy. Analysis of fire scars indicates that at least seven fires have occurred on Mount Constitution since 1736, but only one fire has occurred since 1893, which suggests that the recent increase in stem density has been caused primarily by fire exclusion. The high stem densities currently found in this landscape put the relict (120-350+ years old) Douglas-fir at risk from contemporary fires, which would likely be high-intensity crown fires. Given the transition of forests on Orcas Island during the 20th century to closed canopy structure, undisturbed open-grown coniferous forest is now extremely rare in the San Juan Islands.

  1. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    PubMed

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A; Habel, Jan C

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  2. Forest Fire Ecology.

    ERIC Educational Resources Information Center

    Zucca, Carol; And Others

    1995-01-01

    Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

  3. Teaching Succession with Forests.

    ERIC Educational Resources Information Center

    Stronck, David R.

    1982-01-01

    Suggesting advantages of using forests to teach succession, briefly outlines procedures for gathering evidence of succession including numbers, ages, and sizes of trees. Five plot studies conducted by students at the University of Victoria are also described. (DC)

  4. Trading forest carbon - OSU

    EPA Science Inventory

    Issues associate with trading carbon sequestered in forests are discussed. Scientific uncertainties associated with carbon measurement are discussed with respect to proposed accounting procedures. Major issues include: (1) Establishing baselines. (2) Determining additivity from f...

  5. Benthic meiofaunal composition and community structure in the Sethukuda mangrove area and adjacent open sea, East coast of India

    NASA Astrophysics Data System (ADS)

    Thilagavathi, Balasubramanaian; Das, Bandana; Saravanakumar, Ayyappan; Raja, Kuzhanthaivel

    2011-06-01

    The ecological aspects of meiofaunal communities in the Muthupettai mangrove forest, East coast of India, has not been investigated in the last two decades. Surface water temperature ranged from 23.5 °C to 31.8 °C. Salinity varied from 24 to 34 ppt, while water pH fluctuated from 7.4 to 8.3. Dissolved oxygen concentration ranged from 3.86 to 5.33 mg/l. Meiofauna analysis in this study identified a total of 106 species from the mangrove and adjacent open sea area of Sethukuda. Among these, 56 species of foraminiferans, 20 species of nematodes, 7 species of harpacticoid copepods, 4 species of ostrocodes, and 2 species of rotifers were identified. Furthermore, a single species was identified from the following groups: ciliophora, cnidaria, gnathostomulida, insecta, propulida, bryozoa and polychaete larvae. Meiofaunal density varied between 12029 to 23493 individuals 10 cm/m2. The diversity index ranged from 3.515 to 3.680, species richness index varied from 6.384 to 8.497, and evenness index varied from 0.839 to 0876 in the mangrove area and adjacent open sea.

  6. Sustained carbon uptake and storage following moderate disturbance in a Great Lakes forest.

    PubMed

    Gough, Christopher M; Hardiman, Brady S; Nave, Lucas E; Bohrer, Gil; Maurer, Kyle D; Vogel, Christoph S; Nadelhoffer, Knute J; Curtis, Peter S

    2013-07-01

    Carbon (C) uptake rates in many forests are sustained, or decline only briefly, following disturbances that partially defoliate the canopy. The mechanisms supporting such functional resistance to moderate forest disturbance are largely unknown. We used a large-scale experiment, in which > 6700 Populus (aspen) and Betula (birch) trees were stem-girdled within a 39-ha area, to identify mechanisms sustaining C uptake through partial canopy defoliation. The Forest Accelerated Succession Experiment in northern Michigan, USA, employs a suite of C-cycling measurements within paired treatment and control meteorological flux tower footprints. We found that enhancement of canopy light-use efficiency and maintenance of light absorption maintained net ecosystem production (NEP) and aboveground wood net primary production (NPP) when leaf-area index (LAI) of the treatment forest temporarily declined by nearly half its maximum value. In the year following peak defoliation, redistribution of nitrogen (N) in the treatment forest from senescent early successional aspen and birch to non-girdled later successional species facilitated the recovery of total LAI to pre-disturbance levels. Sustained canopy physiological competency following disturbance coincided with a downward shift in maximum canopy height, indicating that compensatory photosynthetic C uptake by undisturbed, later successional subdominant and subcanopy vegetation supported C-uptake resistance to disturbance. These findings have implications for ecosystem management and modeling, demonstrating that forests may tolerate considerable leaf-area losses without diminishing rates of C uptake. We conclude that the resistance of C uptake to moderate disturbance depends not only on replacement of lost leaf area, but also on rapid compensatory photosynthetic C uptake during defoliation by emerging later successional species.

  7. High-Resolution Modeling Disturbance-Induced Forest Carbon Dynamics with Lidar and Landsat Observations

    NASA Astrophysics Data System (ADS)

    Zhao, M.; Huang, C.; Hurtt, G. C.; Dubayah, R.; Fisk, J.; Sahajpal, R.; Flanagan, S.; Swatantran, A.; Huang, W.; Tang, H.; ONeil-Dunne, J.; Johnson, K. D.

    2015-12-01

    Forest stands are dynamic in a status from severely, partially disturbed, or undisturbed to different stages of recovery towards maturity and equilibrium. Forest ecosystem models generally use potential biomass (an assumption of equilibrium status) as initial biomass, which is unrealistic and could result in unreliable estimates of disturbance-induced carbon changes. To accurately estimate spatiotemporal changes of forest carbon stock and fluxes, it requires accurate information on initial biomass, the extent and severity of disturbance, and following land use. We demonstrate a prototype system to achieve this goal by integrating 1-m small footprint Lidar acquired in year 2004, 30-m Landsat disturbances from 1984 to 2011, and an individual-based structure height Ecosystem Demography (ED) model. Lidar provides critical information on forest canopy height, improving the accuracy of initial forest biomass estimates; impervious surfaces data and yearly disturbance data from Landsat provide information on wall-to-wall yearly natural and anthropogenic disturbances and their severity (on average 0.32% for the natural and 0.19% for the anthropogenic for below test area); ED model plays a central role by linking both Lidar canopy height and Landsat disturbances with ecosystem processes. We tested the system at 90-m spatial resolution in Charles County, Maryland, by running ED model for six experiments, the combinations of three initial biomass (potential, moderate and low initial biomass constrained by Lidar canopy height) with two disturbance scenarios (with and without anthropogenic disturbances). Our experiments show that estimated changes of carbon stock and flux are sensitive to initial biomass status and human-induced land cover change. Our prototype system can assess regional carbon dynamics at local scale under changing climate and disturbance regimes, and provide useful information for forest management and land use policies.

  8. Global carbon impacts of using forest harvest residues for district heating in Vermont

    SciTech Connect

    McLain, H.A.

    1998-07-01

    Forests in Vermont are selectively logged periodically to generate wood products and useful energy. Carbon remains stored in the wood products during their lifetime and in fossil fuel displaced by using these products in place of energy-intensive products. Additional carbon is sequestered by new forest growth, and the forest inventory is sustained using this procedure. A significant portion of the harvest residue can be used as biofuel in central plants to generate electricity and thermal energy, which also displaces the use of fossil fuels. The impact of this action on the global carbon balance was analyzed using a model derived from the Graz/Oak Ridge Carbon Accounting Model (GORCAM). The analysis showed that when forests are harvested only to manufacture wood products, more than 100 years are required to match the sequestered carbon present if the forest is left undisturbed. If part of the harvest residue is collected and used as biofuel in place of oil or natural gas, it is possible to reduce this time to about 90 years, but it is usually longer. Given that harvesting the forest for products will continue, carbon emission benefits relative to this practice can start within 10 to 70 years if part of the harvest residue is used as biofuel. This time is usually higher for electric generation plants, but it can be reduced substantially by converting to cogeneration operation. Cogeneration makes possible a ratio of carbon emission reduction for district heating to carbon emission increase for electricity generation in the range of 3 to 5. Additional sequestering benefits can be realized by using discarded wood products as biofuels.

  9. Neotropical primate communities: Effects of disturbance, resource production and forest type heterogeneity.

    PubMed

    Stevenson, Pablo R

    2015-12-18

    Undisturbed primate communities in the Neotropics are bottom-up structured as their biomass and species richness can be predicted from fruit production. However, the effects of fruit scarcity and the availability of forest types have not been fully analyzed, and seasonality is expected to differently affect small and large monkeys. The first aim of this study was to examine the effect of contrasting forest types within a location on the temporal variation in fruit production. The second was to assess the relative roles of disturbance, climate, patterns of fruit and leaf production, and plant composition on determining Neotropical primate communities. I compiled population density data for diurnal primate species from 154 sites to calculate species richness and assemblage biomass. Fruit abundance in the study sites was estimated from fruit trap data and phenology transects, and fruit variability was calculated as the monthly coefficient of variation (CV) and the length of the fruit scarcity period (LFSP). The results indicate that fruit production in floodplain forests is generally more variable than in terra firme forests, and this variation decreases in habitats with mixed forest types. Endozoochorous fruit production (based on fruit traps) and litter productivity were good predictors of the biomass of Neotropical primates (R(2)  = 0.83 and R(2)  = 0.59, respectively), but neither CV nor LFSP were good predictors. The biomass of large primates was independent of rainfall variation, but the biomass of small and medium sized monkeys was negatively correlated with temporal rainfall variability. Varzea forests tended to show higher biomass than those from terra firme and igapó. These results suggest that the production of fleshy fruits is the best predictor of the structure of primate assemblages in the Neotropics, but the effect of leaf quality and productivity remains to be investigated. Am. J. Primatol. © 2015 Wiley Periodicals, Inc.

  10. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  11. Forests of Mexico

    SciTech Connect

    Cairns, M.A.; Dirzo, R.; Zadroga, F.

    1995-07-01

    Forest of Mexico as elsewhere provide essential goods and services for both local citizens and the international community. Benefits include climate regulation, biodiversity, and wood and nonwood products for local consumption and economic activity. Deforestation is a matter of great environmental and economic concern. This article assesses rates of deforestation, the present status of forest in Mexico, and the major factors responsible for deforestation in the tropical southeastern region.

  12. Effectiveness of mitigation measures with constructed forested wetlands in Maryland

    USGS Publications Warehouse

    Perry, M.C.

    1997-01-01

    Intensive research on six constructed forested wetlands in Central Maryland was conducted in 1993-1996 to determine success of these habitats as functional forested wetlands for wildlife. Areas studied ranged in size from 2 to 35 acres and were constructed by private companies under contract with three mitigation agencies. Adjacent natural forested wetlands were used as reference sites where similar data were collected. Based on data from the first four years of this study it appears that it will take 35-50 years before these areas have forested wetland vegetation and wildlife similar to that found on mature forested wetlands. This long-time period is based on the high mortality and slow growth of nursery-stock trees and shrubs transplanted on the areas. Mortality and slow growth resulted mostly from excessive surface water on the sites. The level of ground water did not appear to be a factor in regard to transplant mortality. Green ash was the woody transplant species that had the least mortality. Sampling of vegetative ground cover with one-meter square quadrats showed the predominance of grasses and herbs. [abridged abstract

  13. Forested wetlands constructed for mitigation of destroyed natural wetlands

    USGS Publications Warehouse

    Perry, M.C.; Pugh, S.B.; Deller, A.S.

    1995-01-01

    Forested wetlands constructed for mitigation were evaluated at six sites in Maryland to determine the success of these areas for providing suitable wildlife habitat. Natural forested wetlands were used as reference sites. Initial mortality of planted woody shrubs and trees was high (avg. 55%) and mostly attributed to excessive moisture. The number of woody seedlings from natural regeneration was inversely proportional to the amount of grass cover on the site, which was planted for erosion control. The number of volunteer woody seedlings was also inversely proportional to the distance from adjacent natural forests. Preliminary data indicate that cost does not support use of transplants and that enhancement of soil with organic supplements, followed by widespread and heavy seeding of woody plants would be more efficient and effective. Wildlife use of areas measured by avian surveys and trapping of mammals, reptiles, and amphibians showed that in general wildlife species were more representative of open grassland areas than forested habitats. Natural succession of the sites probably will take at least 20-30 years before typical values and functions of forested wetlands are obtained.

  14. Forest vegetation monitoring and foliar chemistry of red spruce and red maple at Acadia National Park in Maine.

    PubMed

    Wiersma, G Bruce; Elvir, Jose Alexander; Eckhoff, Janet D

    2007-03-01

    The USDA Forest Service Forest Health Monitoring (FHM) program indicators, including forest mensuration, crown condition classification, and damage and mortality indicators were used in the Cadillac Brook and Hadlock Brook watershed forests at Acadia National Park (ANP) along coastal Maine. Cadillac Brook watershed burned in a wildfire in 1947. Hadlock Brook watershed, undisturbed for several centuries, serves as the reference site. These two small watersheds have been gauged and monitored at ANP since 1998 as part of the Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet). Forest vegetation at Hadlock Brook was dominated by late successional species such as Acer saccharum, Fagus grandifolia, Betula alleghaniensis, Acer rubrum and Picea rubens. Forest vegetation at Cadillac Brook, on the other hand, was younger and more diverse and included those species found in Hadlock as well as early successional species such as Betula papyrifera and Populus grandidentata. Differences in forest species composition and stand structure were attributed to the severe wildfire that affected the Cadillac Brook watershed. Overall, the forests at these ANP watersheds were healthy with a low percentage (

  15. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2012-10-01 2012-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  16. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2010-10-01 2010-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  17. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2011-10-01 2011-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  18. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2013-10-01 2013-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  19. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2014-10-01 2014-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  20. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  1. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  2. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  3. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  4. 38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS NEAR THE CENTER OF THE FACTORY BUILDING. AT THE LEFT FOREGROUND IS A MOVABLE TIRE BENDER FOR SHAPING ELI WINDMILL WHEEL RIMS. AT THE CENTER IS A FLOOR-MOUNTED CIRCA 1900 SNAG GRINDER OF THE TYPE USED FOR SMOOTHING ROUGH CASTINGS. ON THE WHEELED WORK STATION IS A SUNNEN BUSHING GRINDER, BEHIND WHICH IS A TRIPOD CHAIN VICE. IN THE CENTER BACKGROUND IS A WOODEN CHEST OF DRAWERS WHICH CONTAINS A 'RAG DRAWER' STILL FILLED WITH CLOTH RAGS PLACED IN THE FACTORY BUILDING AT THE INSISTENCE OF LOUISE (MRS. ARTHUR) KREGEL FOR THE CONVENIENCE AND CLEANLINESS OF WORKERS. IN THE LEFT BACKGROUND IS A CIRCA 1900 CROSS-CUTOFF CIRCULAR SAW. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  5. Air bubble-shock wave interaction adjacent to gelantine surface

    NASA Astrophysics Data System (ADS)

    Lush, P. A.; Tomita, Y.; Onodera, O.; Takayama, K.; Sanada, N.; Kuwahara, M.; Ioritani, N.; Kitayama, O.

    1990-07-01

    The interaction between a shock wave and an air bubble-adjacent to a gelatine surface is investigated in order to simulate human tissue damage resulting from extracorporeal shock wave lithotripsy. Using high speed cine photography it is found that a shock wave of strength 11 MPa causes 1-3 mm diameter bubbles to produce high velocity microjets with penetration rates of approximately 110 m/s and penetration depths approximately equal to twice the initial bubble diameter. Theoretical considerations for liquid impact on soft solid of similar density indicate that microjet velocities will be twice the penetration rate, i.e. 220 m/s in the present case. Such events are the probable cause of observed renal tissue damage.

  6. Laser ablation of human atherosclerotic plaque without adjacent tissue injury

    NASA Technical Reports Server (NTRS)

    Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

    1985-01-01

    Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

  7. Scolopendromorpha of New Guinea and adjacent islands (Myriapoda, Chilopoda).

    PubMed

    Schileyko, Arkady A; Stoev, Pavel E

    2016-08-04

    The centipede fauna of the second largest island in the world, New Guinea, and its adjacent islands, is poorly known, with most information deriving from the first half of the 20th century. Here we present new data on the order Scolopendromorpha based on material collected in the area in the last 40 years, mainly by Bulgarian and Latvian zoologists. The collections comprise eleven species of six genera and three families. The diagnosis of Cryptops (Trigonocryptops) is emended in the light of the recent findings. The old and doubtful record of Scolopendra multidens Newport, 1844 from New Guinea is referred to S. subspinipes Leach, 1815 and the species is here excluded from the present day list of New Guinean scolopendromorphs. Cryptops nepalensis Lewis, 1999 is here recorded from New Guinea for the first time. An annotated list and an identification key to the scolopendromorphs of the studied region are presented.

  8. Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.

    2013-01-01

    Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best available mapping compiled in an integrated fashion. The map and associated digital files represent part of a systematic effort to release geologic map data for the United States in a uniform manner. The geologic data have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The map data are presented for use at a nominal scale of 1:500,000, although individual datasets (see Wilson and others, 2005) may contain data suitable for use at larger scales.

  9. Change in land use alters the diversity and composition of Bradyrhizobium communities and led to the introduction of Rhizobium etli into the tropical rain forest of Los Tuxtlas (Mexico).

    PubMed

    Ormeño-Orrillo, Ernesto; Rogel-Hernández, Marco A; Lloret, Lourdes; López-López, Aline; Martínez, Julio; Barois, Isabelle; Martínez-Romero, Esperanza

    2012-05-01

    Nitrogen-fixing bacteria of the Bradyrhizobium genus are major symbionts of legume plants in American tropical forests, but little is known about the effects of deforestation and change in land use on their diversity and community structure. Forest clearing is followed by cropping of bean (Phaseolus vulgaris) and maize as intercropped plants in Los Tuxtlas tropical forest of Mexico. The identity of bean-nodulating rhizobia in this area is not known. Using promiscuous trap plants, bradyrhizobia were isolated from soil samples collected in Los Tuxtlas undisturbed forest, and in areas where forest was cleared and land was used as crop fields or as pastures, or where secondary forests were established. Rhizobia were also trapped by using bean plants. Bradyrhizobium strains were classified into genospecies by dnaK sequence analysis supported by recA, glnII and 16S-23S rDNA IGS loci analyses. A total of 29 genospecies were identified, 24 of which did not correspond to any described taxa. A reduction in Bradyrhizobium diversity was observed when forest was turned to crop fields or pastures. Diversity seemed to recover to primary forest levels in secondary forests that derived from abandoned crop fields or pastures. The shifts in diversity were not related to soil characteristics but seemingly to the density of nodulating legumes present at each land use system (LUS). Bradyrhizobium community composition in soils was dependent on land use; however, similarities were observed between crop fields and pastures but not among forest and secondary forest. Most Bradyrhizobium genospecies present in forest were not recovered or become rare in the other LUS. Rhizobium etli was found as the dominant bean-nodulating rhizobia present in crop fields and pastures, and evidence was found that this species was introduced in Los Tuxtlas forest.

  10. Analyzing riparian forest cover changes along the Firniz River in the Mediterranean City of Kahramanmaras in Turkey.

    PubMed

    Akay, Abdullah E; Sivrikaya, Fatih; Gulci, Sercan

    2014-05-01

    Riparian forests adjacent to surface water are important transitional zones which maintain and enrich biodiversity and ensure the sustainability in a forest ecosystem. Also, riparian forests maintain water quality, reduce sediment delivery, enhance habitat areas for aquatic life and wildlife, and provide ecological corridors between the upland and the downstream. However, the riparian ecosystems have been degraded mainly due to human development, forest operations, and agricultural activities. In order to evaluate the impacts of these factors on riparian forests, it is necessary to estimate trends in forest cover changes. This study aims to analyze riparian forest cover changes along the Firniz River located in Mediterranean city of Kahramanmaras in Turkey. Changes in riparian forest cover from 1989 to 2010 have been determined by implementing supervised classification method on a series of Landsat TM imagery of the study area. The results indicated that the classification process applied on 1989 and 2010 images provided overall accuracy of 80.08 and 75 %, respectively. It was found that the most common land use class within the riparian zone was productive forest, followed by degraded forest, agricultural areas, and other land use classes. The results also indicated that the areas of degraded forest and forest openings increased, while productive forest and agricultural areas decreased between the years of 1989 and 2010. The amount of agricultural areas decreased due to the reduction in the population of rural people. According to these results, it can be concluded that special forest management and operation techniques should be implemented to restore the forest ecosystem in riparian areas.

  11. The technology of forest fire detection based on infrared image

    NASA Astrophysics Data System (ADS)

    Wu, Zhi-guo; Liu, Guo-juan; Wang, Ming-jia; Wang, Suo-jian

    2013-09-01

    According to infrared imaging features of forest fire, we use image processing technology which is conducive to early detection and prevention of forest fires. We use image processing technology based on infrared imaging features of forest fire which is conducive to early detection and prevention of forest fires. In order to the timeliness and accuracy of fire detection, this paper proposes a forest fire detection method based on infrared image technology. We take gray histogram analysis to collected Cruising image. The image which will be detected is segmented by the adaptive dynamic threshold. Then the suspected ignitions are extracted in the image after segmentation. The ignition of forest fire which form image in the infrared image is almost circular. We use the circular degree of suspected ignition as the decision basis of the fire in the infrared image. Through the analysis of position correlation which is the same suspected ignition between adjacent frames, we judge whether there is a fire in the image. In order to verify the effectiveness of the method, we adopt image sequences of forest fire to do experiment. The experimental results show that the proposed algorithm under the conditions of different light conditions and complex backgrounds, which can effectively eliminate distractions and extract the fire target. The accuracy fire detection rate is above 95 percent. All fire can be detected. The method can quickly identify fire flame and high-risk points of early fire. The structure of method is clear and efficient which processing speed is less than 25 frames per second. So it meets the application requirement of real-time processing.

  12. Changes in soil biogeochemistry following disturbance by girdling and mountain pine beetles in subalpine forests.

    PubMed

    Trahan, Nicole A; Dynes, Emily L; Pugh, Evan; Moore, David J P; Monson, Russell K

    2015-04-01

    A recent unprecedented epidemic of beetle-induced tree mortality has occurred in the lodgepole pine forests of Western North America. Here, we present the results of studies in two subalpine forests in the Rocky Mountains, one that experienced natural pine beetle disturbance and one that experienced simulated disturbance imposed through bole girdling. We assessed changes to soil microclimate and biogeochemical pools in plots representing different post-disturbance chronosequences. High plot tree mortality, whether due to girdling or beetle infestation, caused similar alterations in soil nutrient pools. During the first 4 years after disturbance, sharp declines were observed in the soil dissolved organic carbon (DOC) concentration (45-51 %), microbial biomass carbon concentration (33-39 %), dissolved organic nitrogen (DON) concentration (31-42%), and inorganic phosphorus (PO4(3-)) concentration (53-55%). Five to six years after disturbance, concentrations of DOC, DON, and PO4(3-) recovered to 71-140 % of those measured in undisturbed plots. Recovery was coincident with observed increases in litter depth and the sublitter, soil O-horizon. During the 4 years following disturbance, soil ammonium, but not nitrate, increased to 2-3 times the levels measured in undisturbed plots. Microbial biomass N increased in plots where increased ammonium was available. Our results show that previously observed declines in soil respiration following beetle-induced disturbance are accompanied by losses in key soil nutrients. Recovery of the soil nutrient pool occurs only after several years following disturbance, and is correlated with progressive mineralization of dead tree litter.

  13. Response of Gopher Tortoises to Habitat Manipulation by Prescribed Burning: Can Forested Areas Adjacent to Training Areas Be Improved

    DTIC Science & Technology

    2006-04-01

    Herpetology , 26: 158–165. Dietlein, N.E., and R. Franz (1979) Status and habits of Gopherus polyphemus. In Proceedings, 1979 Symposium of the Desert Tortoise...Nesting and hatchling ecology of Gopher Tortoises (Gopherus polyphemus) in southern Mississippi. Journal of Herpetology , 37: 315–324. 38 ERDC/CERL TR-06

  14. The effects of timber harvesting on the structure and composition of adjacent old-growth coast redwood forest, California, USA

    USGS Publications Warehouse

    Russell, W.H.; Jones, C.

    2001-01-01

    Data collected across timber harvest boundaries on nine sites within the Redwood National and State Park management area in California, USA, were used to estimate the effective size of old-growth coast redwood preserves. Fourteen variables related to stand structure and composition, wildlife habitat, and physical environment were significantly correlated to distance from the timber harvest boundary using multiple regression analysis. A maximum depth of edge influence of 200 m was determined for variables exhibiting a significant correlation to the distance from the harvest edge. A spatial analysis using ArcView indicated that 53% of the old growth preserved within the study area was influenced by edge conditions, leaving 47% as effective old-growth.

  15. 75 FR 3442 - Tahoe National Forest, California, Tahoe National Forest Motorized Travel Management Supplemental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Tahoe National Forest, California, Tahoe National Forest Motorized Travel Management Supplemental Draft EIS AGENCY: Forest Service, USDA. ACTION: Notice of intent to prepare a supplemental draft environmental impact statement. SUMMARY: The Tahoe National Forest (TNF)...

  16. Assessment of Bacterial bph Gene in Amazonian Dark Earth and Their Adjacent Soils

    PubMed Central

    Brossi, Maria Julia de Lima; Mendes, Lucas William; Germano, Mariana Gomes; Lima, Amanda Barbosa; Tsai, Siu Mui

    2014-01-01

    Amazonian Anthrosols are known to harbour distinct and highly diverse microbial communities. As most of the current assessments of these communities are based on taxonomic profiles, the functional gene structure of these communities, such as those responsible for key steps in the carbon cycle, mostly remain elusive. To gain insights into the diversity of catabolic genes involved in the degradation of hydrocarbons in anthropogenic horizons, we analysed the bacterial bph gene community structure, composition and abundance using T-RFLP, 454-pyrosequencing and quantitative PCR essays, respectively. Soil samples were collected in two Brazilian Amazon Dark Earth (ADE) sites and at their corresponding non-anthropogenic adjacent soils (ADJ), under two different land use systems, secondary forest (SF) and manioc cultivation (M). Redundancy analysis of T-RFLP data revealed differences in bph gene structure according to both soil type and land use. Chemical properties of ADE soils, such as high organic carbon and organic matter, as well as effective cation exchange capacity and pH, were significantly correlated with the structure of bph communities. Also, the taxonomic affiliation of bph gene sequences revealed the segregation of community composition according to the soil type. Sequences at ADE sites were mostly affiliated to aromatic hydrocarbon degraders belonging to the genera Streptomyces, Sphingomonas, Rhodococcus, Mycobacterium, Conexibacter and Burkholderia. In both land use sites, shannon's diversity indices based on the bph gene data were higher in ADE than ADJ soils. Collectively, our findings provide evidence that specific properties in ADE soils shape the structure and composition of bph communities. These results provide a basis for further investigations focusing on the bio-exploration of novel enzymes with potential use in the biotechnology/biodegradation industry. PMID:24927167

  17. Assessment of bacterial bph gene in Amazonian dark earth and their adjacent soils.

    PubMed

    Brossi, Maria Julia de Lima; Mendes, Lucas William; Germano, Mariana Gomes; Lima, Amanda Barbosa; Tsai, Siu Mui

    2014-01-01

    Amazonian Anthrosols are known to harbour distinct and highly diverse microbial communities. As most of the current assessments of these communities are based on taxonomic profiles, the functional gene structure of these communities, such as those responsible for key steps in the carbon cycle, mostly remain elusive. To gain insights into the diversity of catabolic genes involved in the degradation of hydrocarbons in anthropogenic horizons, we analysed the bacterial bph gene community structure, composition and abundance using T-RFLP, 454-pyrosequencing and quantitative PCR essays, respectively. Soil samples were collected in two Brazilian Amazon Dark Earth (ADE) sites and at their corresponding non-anthropogenic adjacent soils (ADJ), under two different land use systems, secondary forest (SF) and manioc cultivation (M). Redundancy analysis of T-RFLP data revealed differences in bph gene structure according to both soil type and land use. Chemical properties of ADE soils, such as high organic carbon and organic matter, as well as effective cation exchange capacity and pH, were significantly correlated with the structure of bph communities. Also, the taxonomic affiliation of bph gene sequences revealed the segregation of community composition according to the soil type. Sequences at ADE sites were mostly affiliated to aromatic hydrocarbon degraders belonging to the genera Streptomyces, Sphingomonas, Rhodococcus, Mycobacterium, Conexibacter and Burkholderia. In both land use sites, shannon's diversity indices based on the bph gene data were higher in ADE than ADJ soils. Collectively, our findings provide evidence that specific properties in ADE soils shape the structure and composition of bph communities. These results provide a basis for further investigations focusing on the bio-exploration of novel enzymes with potential use in the biotechnology/biodegradation industry.

  18. Record-setting forest stress in the Rocky Mountains caused by low snowfall and high potential evapotranspiration, consistent with expected future conditions

    NASA Astrophysics Data System (ADS)

    Molotch, Noah; Trujillo, Ernesto

    2014-05-01

    Projections of future climate for the Southwestern U.S. and other semi-arid regions globally include reductions in mountain snow accumulation and increased summer potential evapotranspiration. These changes may significantly alter runoff production, evapotranspiration, and gross primary productivity in mountain forests. Analysis of remotely sensed vegetation greenness data indicate strong forest and understory growth dependencies associated with snow accumulation and snowmelt with peak snow water equivalent explaining 40-50% of inter-annual variability in forest greenness in the Sierra Nevada and Rocky Mountains. Examples of these dependencies will be presented based on the 2012 drought in the Southwestern US whereby near record low snow accumulation and record high potential evapotranspiration have resulted in record low forest greening as evident in the 30+ year satellite record. Forest response to aridity in 2012 was exacerbated by forest disturbance with greenness anomalies 90% greater in magnitude in Bark Beetle and Spruce Budworm affected areas versus undisturbed areas and 182% greater in magnitude in areas impacted by fire. Given potential future changes in the hydroclimatology of mountainous regions, the results of these measurements may identify tipping points regarding ecosystem responses to water availability across gradients in physiography.

  19. Aspen Increase Soil Moisture, Nutrients, Organic Matter and Respiration in Rocky Mountain Forest Communities

    PubMed Central

    Buck, Joshua R.; St. Clair, Samuel B.

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO3 and NH4 were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development. PMID:23285012

  20. Influences of Different Large Mammalian Fauna on Dung Beetle Diversity in Beech Forests

    PubMed Central

    Enari, Hiroto; Koike, Shinsuke; Sakamaki, Haruka

    2013-01-01

    This paper focuses on biological relationships between mammalian species richness and the community structure of dung beetles in cool-temperate forests in the northernmost part of mainland Japan. The composition of beetle assemblages was evaluated at 3 sites in undisturbed beech forests with different mammalian fauna. In spring and summer 2009, beetles were collected at each site using pitfall traps baited with feces from Japanese macaques, Macaca fuscata Blyth (Primates: Cercopithecidae); Asiatic black bears, Ursus thibetanus Cuvier (Carnivora: Ursidae); Japanese serows, Capricornis crispus Temminck (Artiodactyla: Bovidae); and cattle. In the present study, 1,862 dung beetles representing 14 species were collected, and most dung beetles possessed the ecological characteristic of selecting specific mammalian feces. The present findings indicated that although species diversity in dung beetle assemblages was not necessarily positively correlated with mammalian species richness in cool-temperate forests, the absence of the macaque population directly resulted in the marked reduction of the beetle abundance, with the loss of the most frequent species, Aphodius eccoptus Bates (Coleoptera: Scarabaeidae) during spring. PMID:23909510