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- Southern Appalachian (3)
- Douglas-fir (2)
- Forest soils (2)
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- Spruce-fir forest (2)
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- Anion (1)
- Aquatic conservation (1)
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Articles 1 - 10 of 10
Full-Text Articles in Life Sciences
Conservation Of Aquatic Biodiversity In The Context Of Multiple-Use Management On National Forest System Lands, Brett B. Roper, James M. Capurso, Yvette Paroz, Michael K. Young
Conservation Of Aquatic Biodiversity In The Context Of Multiple-Use Management On National Forest System Lands, Brett B. Roper, James M. Capurso, Yvette Paroz, Michael K. Young
Watershed Sciences Faculty Publications
The U.S. Department of Agriculture Forest Service (USFS) manages 193 million acres of public lands across 43 states and Puerto Rico. The original intent behind reserving lands managed by the USFS was to improve and protect forests, secure favorable conditions for water flows, and furnish a continuous supply of timber for the nation. Through time national forests have evolved, so they are managed for a broad array of uses. Differing expectations have led to conflicts between aquatic conservation and other aspects of the USFS’ mandate. In the 1990s, these conflicting goals came to a head with the listing of the …
Relative Role Of Understory And Overstory In Carbon And Nitrogen Cycling In A Southern Appalachian Spruce-Fir Forest, P. T. Moore, H. Van Miegroet, N. S. Nicholas
Relative Role Of Understory And Overstory In Carbon And Nitrogen Cycling In A Southern Appalachian Spruce-Fir Forest, P. T. Moore, H. Van Miegroet, N. S. Nicholas
Watershed Sciences Faculty Publications
This study investigated aboveground pools and fluxes of biomass, carbon (C), and nitrogen (N) in the overstory and understory of a southern Appalachian red spruce (Picea rubens Sarg.) – Fraser fir (Abies fraseri (Pursh) Poir.) forest, following adelgid-induced fir mortality and spruce windthrow. Using fifty 20 m × 20 m plots, stratified by elevation (1700–1900 m), we estimated standing biomass and fluxes of all growth forms from periodic stand inventories (1998–2003), vegetation surveys, and existing or derived allometric equations. Total C and N pools and fluxes were calculated from plant- and tissue-specific C and N concentrations. Total aboveground biomass attained …
Soil Organic Carbon Dynamics Along A Climatic Gradient In A Southern Appalachian Spruce-Fir Forest, C. E. Tewksbury, H. Van Miegroet
Soil Organic Carbon Dynamics Along A Climatic Gradient In A Southern Appalachian Spruce-Fir Forest, C. E. Tewksbury, H. Van Miegroet
Watershed Sciences Faculty Publications
A field study was conducted in a high-elevation spruce–fir (Picea rubens Sarg. – Abies fraseri (Pursh.) Poir) forest in the Great Smoky Mountains National Park to assess the effect of temperature on soil C storage and dynamics. In eight plots along an elevation gradient (1500–1900 m), we measured soil temperature, forest floor and mineral soil C, litter decomposition, soil respiration, and forest floor mean residence time. Mean annual soil temperature and annual degree-days above 5 °C were inversely correlated with elevation. Total soil C (166–241 Mg·ha–1) showed no trend with elevation, while forest floor C accumulation (16.3–35.9 Mg·ha–1) decreased significantly …
Variation In Overstory Nitrogen Uptake In A Small, High-Elevation Southern Appalachian Spruce-Fir Watershed, M. Barker, H. Van Miegroet, N. S. Nicholas, I. F. Creed
Variation In Overstory Nitrogen Uptake In A Small, High-Elevation Southern Appalachian Spruce-Fir Watershed, M. Barker, H. Van Miegroet, N. S. Nicholas, I. F. Creed
Watershed Sciences Faculty Publications
High-elevation red spruce (Picea rubens Sarg.) – Fraser fir (Abies fraseri (Pursh) Poir.) forests of the southern Appalachians exhibit considerable spatial heterogeneity in structure, and possibly in N uptake, because of a combination of natural disturbances and heavy fir mortality caused by infestations of the exotic balsam woolly adelgid (Adelges piceae Ratz). The objectives of this study are to determine spatial variability in tree N uptake in a small high-elevation catchment in the Great Smoky Mountains National Park, compare outcomes among calculation methods, and assess the influence of stand and landscape properties on N uptake. Tree N uptake is estimated …
Inorganic Nitrogen Determined By Laboratory And Field Extractions Of Two Forest Soils, H. Van Miegroet
Inorganic Nitrogen Determined By Laboratory And Field Extractions Of Two Forest Soils, H. Van Miegroet
Watershed Sciences Faculty Publications
To assess the effect of a delay in soil processing on inorganic N levels in N-rich soils, field and laboratory extractions were compared at two forested sites with high N mineralization and nitrification potential. At eight sampling dates in 1989 and 1990, five mineral soil cores per site were taken between 0- and 10-cm depth and transported on ice to the laboratory for KCl extraction and NH4-N and NO3-N analysis. At three sampling dates in 1990, soil extractions were performed in the field immediately following sampling, and inorganic N concentrations were compared between extractions. Nitrate-N increased four- to sevenfold (net …
Soil Chemistry And Nutrition Of North American Red Spruce-Fir Stands: Evidence For Recent Change, J. D. Joslin, J. M. Kelly, H. Van Miegroet
Soil Chemistry And Nutrition Of North American Red Spruce-Fir Stands: Evidence For Recent Change, J. D. Joslin, J. M. Kelly, H. Van Miegroet
Watershed Sciences Faculty Publications
One set of hypotheses offered to explain the decline of red spruce (Picea rubens Sarg.) in eastern North America focuses on the effect of acidic deposition on soil chemistry changes that may affect nutrient availability and root function. Long-term soils data suggest that soil acidification has occurred in some spruce stands over the past 50 yr, with plant uptake and cation leaching both contributing to the loss of cations. Studies of tree ring chemistry also have indicated changes in Ca/Al and Mg/Al ratios in red spruce wood, suggesting increases in the ionic strength of soil solution. Irrigation studies using strong …
Soil Nitrogen Dynamics Following Harvesting And Conversion Of Red Alder And Douglas-Fir Stands, H. Van Miegroet, P. S. Homann, D. W. Cole
Soil Nitrogen Dynamics Following Harvesting And Conversion Of Red Alder And Douglas-Fir Stands, H. Van Miegroet, P. S. Homann, D. W. Cole
Watershed Sciences Faculty Publications
Drastic reductions in NO3- leaching have been observed after harvesting of mature red alder (Alnus rubra Bong.) stands. Our objective was to examine whether these reduction were linked to changes in soil N dynamics. Adjacent alder and Douglas fir [Pseudotsuga menziessii (Mirbel.) Franco] stands on young glacial soils (Alderwood; a loamy-skeletal, mixed, mesic, ortstein Aquic Haplorthod) in western Washington were harvested and replanted with either alder or Douglas fir seedlings; reference plots were established in nearby undisturbed stands. Three years after site conversion, when NO3- leaching declined most drastically in the harvested alder plots, net N mineralization and net nitrification …
Factors Affecting Anion Movement And Retention In Four Forest Soils, D. W. Johnson, D. W. Cole, H. Van Miegroet, F. W. Horng
Factors Affecting Anion Movement And Retention In Four Forest Soils, D. W. Johnson, D. W. Cole, H. Van Miegroet, F. W. Horng
Watershed Sciences Faculty Publications
Three hypotheses concerning the movement and retention of anions in forest soils were tested in a series of laboratory and field studies on two Tennessee Ultisols with mixed deciduous forest cover and two Washington Inceptisols, one with deciduous (red alder Alnus rubra Bong.) and one with coniferous [Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco] forest cover. The first hypothesis, that sulfate and phosphate retention was related to adsorption to free Fe and Al oxides, which were in turn related to soil parent material and degree of weathering, was not supported by results of laboratory and field studies. The young, relatively unweathered Washington …
Acidification Sources In Red Alder And Douglas-Fir Soils -- Importance Of Nitrification, H. Van Miegroet, D. W. Cole
Acidification Sources In Red Alder And Douglas-Fir Soils -- Importance Of Nitrification, H. Van Miegroet, D. W. Cole
Watershed Sciences Faculty Publications
Precipitation, throughfall, forest floor, and soil leachate samples were monitored continuously in 1981 and 1982 in a N-poor Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] forest and a red alder (Alnus rubra Bong.) forest growing adjacently on a glacial soil in western Washington. The purpose of the study was to quantify the relative importance of atmospheric vs. natural sources of H+ input to forest soil acidification, and to determine the role of N transformation processes in the overall H+ balance of soils with different N status. Rainwater samples had an avg pH of 4.7 and annual H+ deposition via precipitation averaged 320 …
The Impact Of Nitrification On Soil Acidification And Cation Leaching In A Red Alder Ecosystem, H. Van Miegroet, D. W. Cole
The Impact Of Nitrification On Soil Acidification And Cation Leaching In A Red Alder Ecosystem, H. Van Miegroet, D. W. Cole
Watershed Sciences Faculty Publications
The objectives of this study were to investigate the impacts of internal nitrification on soil and soil solution acidity and on the rate of nutrient export through NO3– mediated leaching. This was achieved by comparing soil chemical properties and soil solution composition within a naturally N-rich red alder (Alnus rubra Bong.) ecosystem to those of an adjacent Douglas-fir [Pseudotsuga menziesil (Mirbel) Franco] forest where soil N levels were significantly lower and no measurable HNO3 production could be observed. In the red alder system, where > 100 kg ha–1 yr–1 of N were added through symbiotic N2 fixation, the net annual NO3– …