K.J. Elliott

United States Department of Agriculture | USDA · Forest Service (FS)

Many currently forested areas in the southern Appalachians were harvested in the early 1900s and cleared for agriculture or pasture, but have since been abandoned and reverted to forest (old-field succession). Land-use and land-cover changes such as these may have altered the timing and quantity of water yield (Q). We examined 80 years of streamflo...

Many currently forested areas in the southern Appalachians were harvested in the early 1900s and cleared for agriculture or pasture, but have since been abandoned and reverted to forest (old-field succession). Land use and land cover changes such as these may have altered the timing and quantity of water yield (Q). We examined 80 years of streamflo...

In mountainous areas such as the southern Appalachians USA, riparian zones are difficult to define. Vegetation is a commonly used riparian indicator and plays a key role in protecting water resources, but adequate knowledge of floristic responses to riparian disturbances is lacking. Our objective was to quantify changes in stand-level floristic div...

The pace of environmental and socioeconomic change over the past 100 years has been rapid. Changes in fire regimes, climate, and land use have shaped the structure and function of most forest ecosystems, including oak (Quercus spp. L.) forests in the eastern United States. New stressors such as air pollution and invasive species have contributed to...

Climate change and forest disturbances are threatening the ability of forested mountain watersheds to provide the clean, reliable, and abundant fresh water necessary to support aquatic ecosystems and a growing human population. Here we used 76 years of water yield, climate, and field plot vegetation measurements in six unmanaged, reference watershe...

Exurban development (e.g., second homes) in woodlands spreads urban land use impacts beyond suburbs, but because exurban developments often retain many components of original ecosystem structure-such as a forest canopy rather than open lawn-their ecological impacts may be underestimated. Changes in seed-dispersing ant behavior prompted by exurban l...

Climate change will affect tree species growth and distribution; however, under the same climatic conditions species may differ in their response according to site conditions. We evaluated the climate-driven patterns of growth for six dominant deciduous tree species in the southern Appalachians. We categorized species into two functional groups bas...

The importance of the herbaceous layer in regulating ecosystem processes in deciduous forests is generally unknown. We use a manipulative study in a rich, mesophytic cove forest in the southern Appalachians to test the following hypotheses: (i) the herbaceous functional group (HFG) in meso-phytic coves accelerates carbon and nutrient cycling , (ii)...

This chapter provides a synthesis of the more than 30 years of research on Watershed 7 (WS 7) at Coweeta Hydrologic Laboratory. It argues that findings from WS 7 provide important information on the management of southern Appalachians mixed-hardwood forests. The WS 7 study provides an opportunity to conduct detailed research on the effectiveness of...

Few studies have examined how insect outbreaks affect landscape-level hydrologic processes. We report the hydrologic effects of the invasive, exotic hemlock woolly adelgid (HWA) in a headwater catchment in the southern Appalachian Mountains. The study watershed experienced complete mortality of an evergreen tree species, Tsuga canadensis (L.) Carr....

Understanding the patterns of past disturbance allows further insight into the complex composition, structure, and function of current and future forests, which is increasingly important in a world where disturbance characteristics are changing. Our objectives were to define disturbance causes, rates (percent disturbance per decade), magnitudes and...

We synthesized the current information on mesophytic cove forests in the southern Appalachians, assessed the range of variation in herb species composition and diversity in stands with different disturbance histories and environmental conditions, identified key knowledge gaps, and suggested approaches to fill these knowledge gaps. The purpose of th...

Background/Question/Methods Climate change poses challenges for forest management and conservation to determine how to maintain forests under novel climates. Temperature increases and precipitation changes, in particular, are likely to become a major factor limiting tree species growth and distribution. Trees growing under the same climatic condi...

Background/Question/Methods Few studies have examined how insect outbreaks affect landscape-level hydrologic and biogeochemical processes. Here, we report the hydrologic and biogeochemical effects of the invasive, exotic Hemlock Woolly Adelgid (Adelges tsugae Annand; HWA) in a headwater catchment in the southern Appalachian mountains. The study a...

In the southern Appalachians, Rhododendron maximum L. (Ericaceae) is a key evergreen understory species, often forming a subcanopy in forest stands. Little is known about the significance of R. maximum cover in relation to other forest structural variables. Only recently have studies used Global Positioning System (GPS) technology as a field-based...

The impacts of exotic insects and pathogens on forest ecosystems are increasingly recognized, yet the factors influencing the magnitude of effects remain poorly understood. Eastern hemlock (Tsuga canadensis) exerts strong control on nitrogen (N) dynamics, and its loss due to infestation by the hemlock woolly adelgid (Adelges tsugae) is expected to...

Background/Question/Methods Numerous paired watershed studies have addressed the role of forests in regulating water yield and have demonstrated the tight interaction between vegetation and streamflow production. New challenges, such as the effects of non-random species loss on water yield, are emerging, and are already influencing forested ecosy...

Background/Question/Methods We chose a rich, mesophytic cove forest in the Coweeta Basin, western North Carolina to evaluate the role of a diverse herbaceous layer in ecosystem function. We hypothesized that the experimental removal of a functional group of species would alter ecosystem processes. In summer 1998, we established 6 replicates of he...

The death of eastern hemlock (Tsuga canadensis) trees in response to infestation by the introduced hemlock woolly adelgid (Adelges tsugae) may affect ecosystem processes and structure of streams. Prior to hemlock mortality, we documented the conditions of eight small streams and their associated riparian forests within the Appalachian Mountains of...

In the Southern Appalachian Mountains of eastern USA, pine-hardwood ecosystems have been severely impacted by the interactions of past land use, fire exclusion, drought, and southern pine beetle (SPB, Dendroctonus frontalis). We examined the effects of restoration treatments: burn only (BURN); cut + burn on dry sites (DC + B); cut + burn on sub-mes...

Aims Wilderness and other natural areas are threatened by large-scale disturbances (e.g., wildfire), air pollution, climate change, exotic diseases or pests, and a combination of these stress factors (i.e., stress complexes). Linville Gorge Wilderness (LGW) is one example of a high elevation wilderness in the southern Appalachian region that has be...

Rhododendron maximum L. is an evergreen, clonal shrub that forms a dominant sub-canopy layer and is a key species in southern Appalachian forests. We investigated the age and distribution of R. maximum across the Coweeta Basin, a 1626 ha watershed in western North Carolina. We selected 16 perennial, second-order streams and used a Global Positionin...

Understanding changes in community composition caused by invasive species is critical for predicting effects on ecosystem function, particularly when the invasive threatens a foundation species. Here we focus on dynamics of forest structure, composition and microclimate, and how these interact in southern Appalachian riparian forests following inva...

The herbaceous layer varies with topographic heterogeneity and harbors the great majority of plant diversity in eastern deciduous forests. We described the interplay between disturbances, both natural and human-caused, and composition, dynamics, and diversity of herbaceous vegetation, especially those in early successional habitats. Management acti...

Long-term records from USDA Forest Service Experimental Forests and Ranges (EF&Rs) are exceptionally valuable scientific resources and common ground for research in natural resource management. Coweeta Hydrologic Laboratory, Southern Appalachian Mountains in western North Carolina, is one of 82 EF&Rs located throughout the United States and Puerto...

Background/Question/Methods Despite the implementation of various biological and chemical controls, eastern hemlock trees (Tsuga canadensis (L.) Carr.) are declining throughout much of the eastern US due to hemlock woolly adelgid (HWA). The decline is especially rapid in the southern Appalachian region of the US. We used a combination of intensive...

We examined the relationships between hemlock distribution and abundance and terrain attributes for the Coweeta Basin in the southern Appalachian Mountains. Field measurements were combined with GIS mapping methods to develop predictive models of abundance and distribution of Tsuga canadensis (L.) Carrière (eastern hemlock) and evaluate the co-occu...

We characterized structural and functional attributes along hillslope gradients in headwater catchments. We endeavored to identify parameters that described significant transitions along the hillslope. On each of four catchments, we installed eight 50m transects perpendicular to the stream. Structural attributes included woody and herbaceous vegeta...

We examined vegetation responses to prescribed fire on three mixed-oak sites located in the Blue Ridge Physiographic province of the southern Appalachian Mountains: Alarka Laurel Branch (AL), Robin Branch (RB), and Roach Mill Branch (RM). Each of the study sites was within a sub-watershed that drained a first order stream. Our objectives were to: 1...

We examined the long-term effects of a prescribed fire in a southern Appalachian watershed in Nantahala National Forest, western North Carolina, USA. Fire was prescribed in 1995 on this site by forest managers to restore a degraded pine (Pinus spp.)-hardwood community, specifically to stimulate forage production, promote pine and oak (Quercus spp.)...

We examined nutrient cycling responses to prescribed fire on three sub-mesic, mixed-oak sites located in the Blue Ridge Physiographic province of the southern Appalachian Mountains: Alarka Laurel Branch (AL), Robin Branch (RB), and Roach Mill Branch (RM). Each study site was located within a sub-watershed that drained a first order stream. Our obje...

Elliott, K. J. and J. M. Vose (Coweeta Hydrologic Laboratory, Southern Research Station, USDA Forest Service, Otto, NC 28763). Effects of prescribed burning on shortleaf pine (Pinus echinata Mill.)/mixed-hardwood forests. J. Torrey Bot. Soc. 132: 236-251. 2005.-We examined the effects of a single dormant season fire on overstory and understory spec...

We predicted the eff ects of sulfate (SO 4) deposition on wilderness areas designated as Class I air quality areas in western North Carolina using a nutrient cycling model (NuCM). We used three S deposition simulations: current, 50% decrease, and 100% increase. We measured vegetation, forest fl oor, and root biomass and collected soil, soil solutio...

Chestnut blight fungus (Endothia parasitica [Murr.] P.J. And. & H.W. And.)) is a classic example of an invasive species, which severely damaged populations of its host, Castanea dentata, and had widespread and long-term impacts on eastern North American forests. Concurrently, forests were further disturbed by lumbering, which was common across the...

Cover board arrays were used to measure the relative abundance of macroinvertebrates and terrestrial salamanders on prescribed burn and control sites in xeric southern Appalachians of northern Georgia and southeastern Tennessee pine-oak forests. Three microsite variables were measured at each cover board: cover board moisture level, temperature und...

In many forested ecosystems, the architecture and functional ecology of certain tree species define forest structure and their species-specific traits control ecosystem dynamics. Such foundation tree species are declining throughout the world due to introductions and outbreaks of pests and pathogens, selective removal of individual taxa, and over-h...

Transpiration is a key process in the application of phytoremediation to soil or groundwater pollutants. To be successful, vegetation must transpire enough water from the soil or groundwater to control or take up the contaminant. Transpiration is driven by a combination of abiotic (climate, soil water availability, and groundwater depth) and biotic...

We evaluated the effects of three regeneration harvest methods on plant diversity and soil resource availability in mixed-hardwood ecosystems. The study area is in the Wine Spring Creek watershed on the Nantahala National Forest of the Southern Appalachian Mountains in western North Carolina. The regeneration treatments were: an irregular, two-aged...

Prescribed burning is being used in the Conasauga River Watershed in southeastern Tennessee and northern Georgia by National Forest managers to restore degraded pine/oak communities. The purpose of these burns is to restore shortleaf pine (Pinus echinata Miller)/mixed-oak forests with more diverse understories, which include native bluestem grasses...

As a result of this most recent SPB epidemic (1999-2003), thousands of hectares of dead pine trees have created wildfire-hazard conditions in the southern Appalachians. One of the challenges for land managers is how to return fire to these ecosystems after (1) nearly a decade of exclusion, and (2) the more recent SPB mortality enhanced fuel loads....

Understory prescribed burning is being suggested as a viable management tool for restoring degraded oak–pine forest communities in the southern Appalachians yet information is lacking on how this will affect ecosystem processes. Our objectives in this study were to evaluate the watershed scale effects of understory burning on total aboveground biom...

Transpiration is a key process in the application of phytoremediat ion 'to soil or groundwater pollutants. To be successful, vegetation must transpire . enough water from the soil or groundwater to control or take up the,cdntam- in&. Transpiration is driven by a combination of abiotic (climate, soil water availability, and groundwater depth) and bi...

Information is lacking on ecosystem effects of understory burning in mesic mixed-oak (Quercus spp.) forests of the southern Appalachians. Native Americans used periodic fires in these forests for driving game and opening the forest. In April 1998, we conducted a low- to moderate-intensity fire in a cove-hardwood forest in the Nantahala National For...

Southern Appalachian forests are undergoing considerable change due to altered disturbance regimes. For example, fire exclusion has had a major impact on the structure and function of pine-hardwood ecosystems. Recently, fire has been prescribed for a variety of applications: 1) stand-replacement in the form of a mimicked wildfire, 2) site-preparati...

In 1975, we initiated a long-term interdisciplinary study of forest watershed ecosystem response to clear-cutting and cable logging in watershed 7 at the Coweeta Hydrologic Laboratory in the southern Appalachian Mountains of North Carolina. This paper describes 20 years of change in species composition, aboveground biomass, leaf area index (LAI), a...

Chainsaw felling, burning, and planting of eastern white pine (Pinus strobus L.) have been prescribed on degraded pine/hardwood stands in the Southern Appalachians to improve overstory composition and productivity. The desired future condition of the overstory is a productive pine/hardwood mixture, with white pine, which is resistant to southern pi...

Disturbance such as catastrophic windthrow can play a major role in the structure and composition of southern Appalachian forests. We report effects of Hurricane Opal followed by salvage logging on vegetation dynamics (regeneration, composition, and diversity) the first three years after disturbance at the Coweeta Hydrologic Laboratory in western N...

Long-term changes (∼20 years) in water yield, the storm hydrograph, stream inorganic chemistry, and sediment yield were analyzed for a 59 ha mixed hardwood covered catchment (Watershed 7) in the southern Appalachian mountains (USA) following clearcutting and cable logging. The first year after cutting, streamflow increased 26 cm or 28% above the fl...

ELLIO~, K. J., J. M. VOSE, W. T SWANK, AND P V. BOLSTAD. Long-term patterns in vegetation-site relationships in a southern Appalachian forest. J. Torrey Bot. Soc. 126320-334. 1999.-W- used permanent plot inventories from 1969-1973 and 1988-1993 to describe forest species distribution patterns of the Coweeta Hydrologic Laboratory, a 2,185 ha basin i...

In April 1995, the USDA Forest Service conducted a prescribed burn along with a south-facing slope of southern Appalachian watershed, Nantahala National Forest, western NC. Fire had been excluded for over 70 years and the purpose of the burn was to create a mosaic of fire intensities to restore a degraded pine/hardwood community and to stimulate fo...

TO document how species richness and diversity (H') recover from severe large-scale disturbance, we report temporal patterns of species composition and diversity following grass-to-forest succession from a long-term experiment in the Coweeta Basin, west-ern North Carolina. The original experiment-clear-cutting, 5 yr of grass cover followed by a her...

Watershed 7, a southwest-facing watershed in the Coweeta Basin, western North Carolina, USA, was clearcut in 1977. Twenty-four permanent plots were inventoried in 1974 before cutting and in 1977, 1979, 1984, and 1993 after clearcutting. This study evaluates changes in species diversity during early succession after clearcutting and differences in o...

We measured growing season soil CO2 evolution under elevated atmospheric [CO2] and soil nitrogen (N) additions. Our objectives were to determine treatment effects, quantify seasonal variation, and compare two measurement techniques. Elevated [CO2] treatments were applied in open-top chambers containing ponderosa pine (Pinus ponderosa L.) seedlings....

Conversion of low-quality, natural mixed pine/hardwood ecosystems, containing a mountain laurel (Kalmia latifolia L.) dominated understory, to more productive eastern white pine (Pinus strobus L.)/mixed-hardwood systems is a common prescription on relatively xeric southern Appalachian forest sites. We examined the effects of mechanical release, int...

Overstory, shrub-layer, and herbllayer flora composition and abundance patterns in eleven forest sites were studied to evaluate species diversity and richness before implementing three types of harvest treat- ments. The sites were within the Wine Spring Creek Watershed and were classified as high elevation, dry, Quercus rubra-Rhododendron calendula...

We measured growing season soil CO, evolution under elevated atmospheric CO, and soil nitrogen (N) additions. Our objectives were to determine treatment effects, quantify seasonal variation, and determine regulating mechanisms. Elevated CO, treatments were applied in open- top chambers containing 3-year-old ponderosa pine ponderosa Dougl. ex Laws.)...

, ABSTRACT. We evaluated the competitive environment around planted white pine (Pinus strobus L.) seedlings and monitored the response of seedling growth to competition from naturally regenerating herbaceous and woody species for 2 yr after prescribed burning. We eval- uated the ability of distance-inde pendent and distance-dependent competition in...

A 16 ha watershed in the Coweeta Basin was clearcut in 1939 and 1962. Vegetation was inventoried in 1934 and at about 7-year intervals to 1991. After the first clearcut, tree diversity remained high until after the second cut. Diversity based on density and basal area decreased significantly 14 years after the second clearcut and remained low throu...

We measured net photosynthesis, leaf conductance, xylem water potential, and growth of Pinus strobus L. seedlings two years after planting on two clear-cut and burned sites in the southern Appalachians. Multiple regression analysis was used to relate seedling net photosynthesis to vapor pressure deficit, seedling crown temperature, photosynthetical...

The tree and shrub species on a 16-ha watershed in the Coweeta Basin were sampled in 1984 and again in 1991 to determine the effects of drought on tree species composition and basal area growth. Mortality and radial growth were determined for tree species within three community types that represent a moisture gradient from moist to dry: cove-hardwo...

Growth and nutrient use efficiency were determined for red pine (Pinus resinosa Ait.) seedlings grown at various levels of light, nitrogen, and phosphorus. Nutrient use effi- ciency was estimated for nitrogen (NUE) and phosphorus (PUE) and was calculated as biomass production divided by total nutrient content. Seedlings grown in high light had four...

We examined the physiological performance and.growth of Pinus strobus L. seedlings the first growing season after planting on two clear-cut and burned sites in the southern Appalachians. Growth of the seedlings was related to physiological measurements (net photosynthesis (P(N)), transpiration, leaf conductance, and xylem water potential), soil wat...

Three southern Appalachian stands with sparse and unproductive pine-hardwood overstories and dense Kalmia latifolia L. understories were treated to restore productivity and diversity on steep slopes. An adaptation of the fell and burn practice was applied in summer and fall 1990. About one-half of the woody fuels were consumed at each site. A range...

The effects of competition from three northern hardwood tree species on red pine (Pinus resinosa Ait.) seedlings were examined on two clear-cut sites in western Maine. We examined how planted red pine seedlings altered their nutrient use efficiency and shoot morphology under changing environmental conditions and how these changes related to their a...

Pin cherry (Prunuspensylvanica L.f.) and striped maple (Acerpensylvanicum L.) are potentially important competitors of red pine (Pinusresinosa Ait.) planted on recently clear-cut hardwood sites. By experimentally manipulating initial competitor densities on 2.0-m2 plots, we were able to quantify and compare the effects of competitor species on red...

Above-ground biomass distribution, leaf area, above-ground net primary productivity and foliage characteristics were determined for 90- and 350-year-oldPinus edulis-Juniperus monosperma ecosystems on the Colorado Plateau of northern Arizona. These ecosystems have low biomass, leaf area and primary productivity compared with forests in wetter enviro...

Competition between ponderosa pine seedlings and various grasses and forbs was studied on a site in northern Arizona burned in 1982 by a wildfire. Two-year-old pine seedlings were planted in 3.05 x 3.05 m plots in April 1983, followed by the sowing of grass and forb seeds on the same plots in July 1983 after summer rains had begun. Predawn xylem wa...

We used permanent plot inventories of the Coweeta Basin (USDA FS Experimental Forest), Southern Appalachian Mountains of North Carolina (first sampled in 1934 and again in 1969-72 and 1988-93) to describe the distribution of species along an environmental gradient. We also explored the influence of large-scale disturbance on this deciduous forest....

Pine regeneration following wildland fire continues to be a serious prob- lem across the western and southeastern U.S. Frequency of large wildfires has increased over the last several decades and restoration of these burned areas is a major problem confronting land managers. Prescribed fires are used primarily to re- duce heavy fuel loads and secon...

Allometric equations were developed to predict aboveground dry weight of herbaceous and woody species on prescribe-burned sites in the Southern Appalachians. Best-fit least-square regression models were developed using diameter, height, or both, as the independent variables and dry weight as the dependent variable. Coefficients of determination for...

The key components of watershed processes are inputs in precipitation, interactions of vegetation, soil and water including evapotranspiration (water yield), overland flow (erosion), and storage and filtering (nutrients), and outputs in streamflow. Fire effects occur at the vegetation-soil interface and can result in altering overland flow and infi...