Stephen Schoenholtz

Application of poultry litter to southern pine stands represents a potentially attractive litter disposal option. Many pine stands are nutrient-limited and might respond positively to the added nutrients. However, the ability of pine stands to respond to nutrients contained in the litter, as well as contain the nutrients on site, has not been thoroughly investigated. We applied poultry litter to a recently-thinned 8-year-old loblolly pine (Pinus taeda L.) stand at 0, 5.6, and 23 Mg ha-1 (dry-weight basis), supplying 0, 200, and 800 kg N ha-1. Growth was tracked for four growing seasons following application. Average height growth was generally unaffected by treatments over the 4-year period. Diameter, basal area, and total cubic volume increments were all elevated by the litter application over the first three growing seasons, but annual increments in all treatments dropped substantially in year 4. Total basal area and standing volume at end of year 4 were significantly greater in t...

The United States possesses one-fourth of the world's coal resources, with more than 260 billion tons of recoverable reserves (USDOE 2009). Given political instability in world regions from which the US imports energy supplies, national security concerns demand continued use of ...

The variations in discharge and water chemistry among and within headwater catchments are not well understood. Developing a better understanding of the processes that control these variations is crucial to determining how headwater catchments will respond to changes in climate and land use. This dissertation explores how hydrologic processes in headwater catchments may be better understood by utilizing a hydropedological framework, where similar soils are grouped together and considered to be representative of and developed by similar hydrologic and biogeochemical processes. In the first chapter, soil groups, called hydropedological units (HPUs) are found to be indicative of distinct water table regimes characterized by the interquartile range and median of shallow groundwater levels, the percent time water table exists in the soil, and the level of catchment storage at which groundwater responds. The second chapter explores the hydrological processes that may lead to the formation ...

Nicholas Polys, Director of Visual Computing, Affiliate Professor in the Department Computer Science, COE Peter Sforza, Director of the Center for Geospatial Information Technology, CNRE Stephen Eubank, Deputy Director and Professor in NDSSL, the Biocomplexity Institute, Population Health Sciences, and Vet Med; Adjunct Professor, Department of Physics Bryan Lewis, Research Associate Professor, the Biocomplexity Institute

Salinization of freshwaters by human activities is of growing concern globally. Consequences of salt pollution include adverse effects to aquatic biodiversity, ecosystem function, human health, and ecosystem services. In headwater streams of the temperate forests of eastern USA, elevated specific conductance (SC), a surrogate measurement for the major dissolved ions composing salinity, has been linked to decreased diversity of aquatic insects. However, such linkages have typically been based on limited numbers of SC measurements that do not quantify intra-annual variation. Effective management of salinization requires tools to accurately monitor and predict salinity while accounting for temporal variability. Toward that end, high-frequency SC data were collected within the central Appalachian coalfield over 4 years at 25 forested headwater streams spanning a gradient of salinity. A sinusoidal periodic function was used to model the annual cycle of SC, averaged across years and streams. The resultant model revealed that, on average, salinity deviated approximately ±20% from annual mean levels across all years and streams, with minimum SC occurring in late winter and peak SC occurring in late summer. The pattern was evident in headwater streams influenced by surface coal mining, unmined headwater reference streams with low salinity, and larger-order salinized rivers draining the study area. The pattern was strongly responsive to varying seasonal dilution as driven by catchment evapotranspiration, an effect that was amplified slightly in unmined catchments with greater relative forest cover. Evaluation of alternative sampling intervals indicated that discrete sampling can approximate the model performance afforded by high-frequency data but model error increases rapidly as discrete sampling intervals exceed 30 days. This study demonstrates that intra-annual variation of salinity in temperate forested headwater streams of Appalachia USA follows a natural seasonal pattern, driven by interactive influences on water quantity and quality of climate, geology, and terrestrial vegetation. Because climatic and vegetation dynamics vary annually in a seasonal, cyclic manner, a periodic function can be used to fit a sinusoidal model to the salinity pattern. The model framework used here is broadly applicable in systems with streamflow-dependent chronic salinity stress.

Abstract Stream construction is a compensatory mitigation strategy that is commonly used in the Appalachian coalfield, eastern USA, to offset surface-mining impacts to headwater streams. Mitigation assessments currently rely on structural metrics, and there is a paucity of research concerning ecosystem functions in streams constructed for mitigation purposes on mined areas. For eight such constructed streams and four reference streams in the coalfields of southwestern Virginia, we evaluated catchment- and riparian-level land cover, measures of stream ecosystem structure, and riparian litterfall and in-stream leaf breakdown functions across two years. Mean litterfall to reference streams was approximately four times greater than constructed-stream levels. Leaf breakdown rates in coarse-mesh bags were typically faster in reference streams, with reference means exceeding constructed-stream means by 40–50%. Depressed constructed-stream rates resulted from diminished microbial + physicochemical processing of leaves and reduced macroinvertebrate-mediated breakdown. However, breakdown rates in some constructed streams were similar to reference-stream means. Among constructed streams, leaf breakdown rates varied negatively with detention-pond coverage and stream temperature and varied positively with riparian-forest cover. Our results suggest hierarchical relationships among these factors and that rapid establishment of woody riparian canopy could accelerate restoration of organic-matter functions in constructed headwater streams.

ABSTRACT The Valdivian Rainforest Eco-region in Chile (35° - 48° S) has a high conservation priority worldwide. These forests are also keys for social welfare due to their supply of timber as well as ecosystem services. Forests in the Eco-region have been extensively converted to fast growing Pinus radiata and Eucalyptus spp. plantations for timber production promoted by public policies and timber companies. This study describes the results of detailed measurements of hydrology and streamwater chemistry in eight small watersheds in south central Chile, subjected to replacement of native temperate rainforest by exotic Eucalyptus plantations. In this system, watersheds have streamside buffers of native forest (SNFW) with varying widths. Results indicate that retention of SNFW counteracts hydrologic effects of Eucalyptus plantations, which are widely known to reduce water yields. A 1.4% rate of increase of the runoff coefficient for each meter of increase of SNFW was observed. In addition, a decrease in the concentrations of total nitrogen, dissolved inorganic nitrogen (DIN), nitrate- N and different sized fractions of particulate organic matter were found in streams draining these plantations as a function of increasing SNFW. Streamside buffer widths of 17-22 m for total nitrogen and DIN concentrations, and ≥36 m for sediments were required to provide comparable values to reference watersheds (100% native forest). The findings from this study suggest that SNFW may significantly reduce adverse effects from exotic-species forestry plantations on water provision in an area of south central Chile where exotic forest plantations are rapidly expanding. This article is protected by copyright. All rights reserved.

Although considerable research has focused on the influences of logging debris treatments on soil and forest regeneration responses, few studies have identified whether debris effects are mediated by associated changes in competing vegetation abundance. At sites near Matlock, Washington, and Molalla, Oregon, studies were initiated after timber harvest to quantify the effects of three logging debris treatments (dispersed, piled, or removed) on the development of competing vegetation and planted Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ). Each debris treatment was replicated with initial and annual vegetation control treatments, resulting in high and low vegetation abundances, respectively. This experimental design enabled debris effects on regeneration to be separated into effects mediated by vegetation abundance and those independent of vegetation abundance. Two to three years after treatment, covers of Scotch broom ( Cytisus scoparius (L.) Link) at Matlock ...

1 Integrative Science and Solutions for Freshwater Systems Concept Paper A plan to build a signature-strength in Freshwater Systems B.L. Benham, J.A. Czuba, W.C. Hession, L.A. Krometis, D.T. Scott, K. Stephenson, T.W. Thompson, College of Agriculture and Life Sciences D.R. Bork, College of Architecture and Urban Studies E.T. Hester, N.F. Polys, College of Engineering J.D. Ivory, College of Liberal Arts and Human Sciences P.L. Angermeier, L. Castello, C.A. Dolloff, V.R. Emrick, III., J.W. Jones, D.L. McLaughlin, R.B. Meyers, D.J. Orth, S.H. Schoenholtz, J.W. Snodgrass, College of Natural Resources and Environment E.R. Hotchkiss, and E.P. Smith, College of Science

Fifteen tree species, five pine and ten hardwood, were planted on a reclaimed, return-to-contour, strip-mine site in Wise County, Virginia. A systemic herbicide was sprayed on half of each of four experimental blocks prior to the second growing season. After three growing seasons, this treatment resulted in increased survival of five species. Black locust (Robina pseudoacacia) performed best with 90% survival and a tenfold increase in height. Other hardwoods that showed promise were black alder (Alnus glutinosa), sycamore (Platanus occidentalis), and cottonwood (Populus deltoides). As a group, the pines outperformed the hardwoods. Loblolly (Pinus taeda) and Virginia pine (Pinus Virginiana) were the fastest growing, and survival of each was signifcantly higher on the sprayed plots.

... Terry Bousquet, NCASI, Development of QAPP, review of nutrient analyses data conducted at NCASI. ... During the original study, stream flow data were collected using continuous analog recorders housed in 4 ft by 4 ft shelters over 42 inch culvert pipe stilling wells, each of which ...

... Figure 3. Relationship between specific conductance and stream condition index based on data collected by Timpano (2011) at Virginia coalfield streams with excellent habitat, and where non-TDS factors with potential to cause biological stress were minimized. ...

Benthic macroinvertebrate communities in headwater streams influenced by Appalachian coal mining often differ from communities in minimally disturbed streams. Elevated levels of total dissolved solids (TDS) associated with mining have been ...

... Zenah W. Orndorff, W. Lee Daniels and Mike Beck Effects of Total Dissolved Solids in Streams of Southwestern Virginia. Stephen Schoenholtz, David Soucek, Carl Zipper, Anthony Timpano A Working Laboratory at the Powell River Project to Research and Promote ...

Australia and New Zealand are committed to the concept of sustainable forest management. Extensive portions of native forest in each country are managed primarily for conservation purposes. Substantial investment has been made in both countries to establish planted production forests, which together comprise 54% of the global Pinus radiata estate. Financial criteria will determine the extent of planted production forest in the future; but environmental legislation has been enacted to sustain the productive capacity of existing ecosystems. Indicators of forest ecosystem productive capacity should include assessments of trends in growth and yield over time, and be linked to changes in site quality. Detecting change in forest productive capacity due to changes in site quality between rotations remains difficult due to confounding effects of silviculture, genetic stocks, disease and insects, and climate variability and change. Additional site-specific technical information and predictive models are required to develop indicators of sustainable forest management practices for environmental monitoring in plantations at the management unit level. Cost-effective monitoring will involve application of indicators at varying spatial and temporal scales.