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Coweeta LTER Synoptic Data from 49 sampling sites in the Upper Little Tennessee River Basin from 2009 to 2010 (Chemistry Data)

Coweeta LTER researchers sampled fifty-eight stream sites in the Upper Little Tennessee River Basin in February and June of 2009. Sites were selected to represent the range of land cover and land use within the basin. This datasets includes stream chemistry data from both the winter and summer sampling events. A whitepaper on the Synoptic field sampling activites can be found at: http://coweeta.uga.edu/publications/white%20paper%20summary%20of%20synoptic%20sampling.pdf

Coweeta LTER Synoptic Data from 56 sampling sites located in the Upper Little Tennessee River Basin from 2009 (geomorphological)

Coweeta LTER researchers sampled fifty-eight stream sites in the Upper Little Tennessee River Basin in February and June of 2009. Sites were selected to represent the range of land cover and land use within the basin. Samples were taken over three days of stable weather and discharge during periods of baseflow. They were used to characterize conditions across the basin during the growing and the non-growing seasons without the influence of elevated discharge. Each entity represents a table found in the downloadable relational database. NOTE: There is only 1 database to download regardless of which entity you choose. A whitepaper on the Synoptic field sampling activites can be found at: http://coweeta.uga.edu/publications/white%20paper%20summary%20of%20synoptic%20sampling.pdf

Coweeta Synoptic Data from 49 sampling sites in the Upper Little Tennessee River Basin from 2009 to 2010 (drainage area, slope, particle size data)

This data was generated as part of synoptic sampling conducted at the Coweeta LTER between June 2009 and May 2010. 49 wadeable streams with low levels of development were sampled throughout the Upper Little Tennessee River Basin in the Southern Appalachians. This dataset contains the location code (visually categorized basin landcover), drainage area, slope, riparian code (visually categorized riparian conditions), percent fines (<2mm), and median particle size (D50) calculated from a Wolman pebble count. The purpose of this study was to investigate the effects of riparian vegetative conditions on a suite of channel morphological variables. At each site, a uniform 150 meter section of stream was surveyed. Within each reach, the active and bankfull channel widths were measured every 5 meters, where active channel width was defined as the vegetationless channel bed from left vegetation break to right vegetation break. All wood exceeding 10 cm diameter and 1.0 m length were tallied. A Wolman pebble count (N = 100) was conducted on the coarsest riffle in each stream reach. Slopes were measured from the upstream end of riffles over three riffle-to-riffle sequences with a level rod and tape. Riparian conditions at each reach were visually categorized. Drainage area was determined from 2006 Landsat imagery. A whitepaper on the Synoptic field sampling activites can be found at: http://coweeta.uga.edu/publications/white%20paper%20summary%20of%20synoptic%20sampling.pdf

Coweeta Synoptic Data from 49 sampling sites in the Upper Little Tennessee River Basin from 2009 to 2010 (active channel width, bankfull width, and channel depth data)

This data was generated as part of synoptic sampling conducted at the Coweeta LTER between June 2009 and May 2010. 49 wadeable streams with low levels of development were sampled throughout the Upper Little Tennessee River Basin in the Southern Appalachians. Active channel width, bankfull width, and channel depth were measured every 5 meters for 150 meters at synoptic stream sites. Effects of riparian vegetative conditions on a suite of channel morphological variables were investigated: active channel width, variability of width within a reach, large wood frequency, mesoscale habitat distributions, median particle size, and percent fines. At each site, a uniform 150 meter section of stream was surveyed. Within each reach active channel width, bankfull channel width, and channel depth were measured every 5 meters. Active channel width was defined as the vegetationless channel bed from left vegetation break to right vegetation break. A whitepaper on the Synoptic field sampling activites can be found at: http://coweeta.uga.edu/publications/white%20paper%20summary%20of%20synoptic%20sampling.pdf

Coweeta Synoptic Data from 49 sampling sites in the Upper Little Tennessee River Basin from 2009 to 2010 (diameter of LWD data)

This data was generated as part of synoptic sampling conducted at the Coweeta LTER between June 2009 and May 2010. 49 wadeable streams with low levels of development were sampled throughout the Upper Little Tennessee River Basin in the Southern Appalachians. Effects of riparian vegetative conditions on a suite of channel morphological variables were investigated: active channel width, variability of width within a reach, large wood frequency, mesoscale habitat distributions, median particle size, and percent fines. Diameter of large woody debris (LWD) in each stream reach were tallied in this specific dataset. At each site, a uniform 150 meter section of stream was surveyed. All wood in a reach exceeding 10cm diameter and 1.0m length were tallied. Observers kept a tally of the function, if any, of the large woody debris within the channel (e.g. pool formation, jam formation, bank protection, etc.). A whitepaper on the Synoptic field sampling activites can be found at: http://coweeta.uga.edu/publications/white%20paper%20summary%20of%20synoptic%20sampling.pdf

Stream sampling for total suspended solids (TSS), volatile suspended solids (VSS), and chemistry during storm events at the Coweeta LTER intensive and hillslope sites in Macon County, NC.

Stream storm samples were collected at 21 streams and rivers in Macon County, NC. Nine intensive sites were monitored in 2010-2011, nine hillslope sites were monitored in 2012-2013, and three river sites were monitored from 2010-2013. An ISCO water sampler was used to collect stream water samples during storm events. Water samples were analyzed at the Coweeta Analytical Lab.

Habitat suitability and the distribution of species: Polygonatum biflorum demography data from the Coweeta Hydrologic Laboratory from 1998 to 2006

Metapopulation theory posits that suitable habitat may frequently be unoccupied because it is isolated and has never been colonized or has been colonized followed by local extinction and has not yet been recolonized. This research addresses the question of how to identify suitable, unoccupied habitat and distinguish it from unsuitable habitat. We are studying a group of six species of forest understory herbs chosen to represent a broad range of habitat distribution and dispersal characteristics. Our aim is to quantify the fundamental niche of these species (sensu Hutchinson 1957), in terms of variables such as soil moisture and temperature, by developing a set of habitat specific demographic stage transition models (i.e. conditional on such environmental variables) for these species. These models, in combination with data from field surveys of the local distribution of the species, will be used to develop testable predictive maps of the distribution of suitable habitat which can be compared to the observed distribution of the plants. We hypothesize that both dispersal ability and the distribution of suitable habitat are important determinants of the actual distribution of species. The goal of this research is both to further our conceptual understanding of the relationships between habitat requirements and species distributions, and to provide a practical approach to operationalizing the concept of "suitable habitat."

Growth-mortality relationships for southern Appalachian trees from the Coweeta Hydrologic Laboratory in 1995

Ecologists and foresters have long noted a link between tree growth rate and mortality, and recent work suggests that interspecific differences in low growth tolerance is a key force shaping forest structure. Little information is available, however, on the growth-mortality relationship for most species. We present three methods for estimating growth-mortality functions from readily obtainable field data. All use annual mortality rates and the recent growth rates of living and dead individuals. Annual mortality rates are estimated using both survival analysis and a Bayesian approach. Growth rates are obtained from increment cores. Growth-mortality functions are fitted using two parametric approaches and a non-parametric approach. The three methods are compared using bootstrapped confidence intervals and likelihood ratio tests. For two example species, Acer rubrum and Cornus florida, growth-mortality functions indicate a substantial difference in the two species abilities to withstand slow growth. Both survival analysis and Bayesian estimates of mortality rates lead to similar growth-mortality functions, with the Bayesian approach providing a means to overcome the absence of long-term census data. In fitting growth-mortality functions, the non-parametric approach reveals that inflexibility in parametric methods can lead to errors in estimating mortality risk at low growth. We thus suggest that non-parametric fits be used as a tool for assessing parametric models.

Tree seedling densities across an elevation and moisture gradient from the Coweeta Hydrologic Laboratory from 1996 to 1999

First year seedling densities of all woody perennials (trees, vines, shrubs) were censused across five permanent vegetation plots to compare spatial distributions with adult trees, seed densities and seed bank densities.

Rhododendron maximum cover across an elevation gradient from the Coweeta Hydrologic Laboratory from 1997 to 1999

Rhododendron maximum leaf area was measured at 167 locations to determine the spatial extent of this understory shrub, and compare Rhododendron maximum cover with seedling germination rates and seedling diversity (measured in another study). Rhododendron maximum leaf area index was determined at 167 points within each permanent vegetation plot. The initial 86 points were sampled in 1997, and the remainder sampled in the summer of 1999.

Gradient throughfall (thrufall) collection at the Coweeta Hydrologic Laboratory from 1992 to 1997

To investigate long term forest ecosystem responses to disturbance and stress along an elevational gradient, five plots were established as follows: xeric oak-pine (782 m), cove hardwood (795 m), low elevation mixed oak (865 m), high elevation mixed oak (1001 m), and northern hardwoods (1347 m). Phenomena being studied in these plots include: climatology, nutrient dynamics, decomposition, vegetation productivity and population dynamics, and below-ground processes. As part of study on nutrient dynamics, throughfall was sampled weekly and concentrations and fluxes were examined from each of the five gradient plots.

Microclimate Measurements from the Terrestrial Gradient Plots, Coweeta Hydrologic Laboratory, North Carolina

The terrestrial gradient study at Coweeta compares vegetation, soils, and understory microclimate of five sites: 118 low elevation (782 m) pine-oak, 218 low elevation (795 m) cove hardwood, 318 low elevation (865 m) mixed oak, 427 high elevation (1001 m) mixed oak, 527 high elevation (1347 m) northern hardwood. Understory microclimate stations were installed in representative locations at the downslope margin of each 20 x 40 m gradient plot (within the 80 x 80 m plot).

Nitrogen transformation along an elevational and vegetative gradient from the Coweeta Hydrologic Laboratory from 1991 to 1995

Examination of N-transformation along elevation and vegetation gradient. These measurements are analysis of plant nitrogen availability and overall site productivity.

Nitrogen transformation along an elevational and vegetative gradient from the Coweeta Hydrologic Laboratory from 1991 to 1995

Examination of N-transformation along elevation and vegetation gradient. These measurements are analysis of plant nitrogen availability and overall site productivity.

Gap soil moisture at the Coweeta Hydrologic Laboratory from 1993 to 1996

Small canopy openings often alter understory microclimate, leading to changes in forest structure and composition. It is generally accepted that physical changes in the understory (i.e., microclimatic) due to canopy removal drive changes in basic forest processes, particularly seedling recruitment which is intrinsically linked to soil moisture availability, light and, to a lesser extent, temperature. We examined the impact of small canopy gaps of the type (snags) and size (~300 m2) most frequently observed in the southern Appalachians on the understory microclimate. We created artificial canopy gaps at two elevations (a.m.s.l.) by girdling trees in areas with and without a Rhododendron maximum L. (rosebay rhododendron) understory. Soil and air temperature (degrees C), photosynthetically active radiation (PAR; mmol m-2s-1), and volumetric soil water content (WC%) in the upper 15 cm of soil were measured along transects generally running north to south through each gap. Overall, PAR was substantially less in rhododendron gaps than in non-rhododendron gaps.

Gap PAR (Photosynthetic Active Radiation) at the Coweeta Hydrologic Laboratory from 1993 to 1997

Tree census, demography, and exposed canopy area data at the Coweeta LTER Terrestrial Gradient Sites, Coweeta Hydrological Laboratory, Otto, NC from 1993 to 2016

The five Terrestrial Gradient sites were established in the early 1990s as part of the 1990 Coweeta LTER Renewal. The original terrestrial gradient sites were 20 x 40-m. In the late 1990s the plots were expanded to 80 x 80-m and later (around 1998) they were slope-corrected by Clark's lab using survey equipment. Much of the Coweeta LTER “core” datasets have been collected from the gradient plots. This study is one of the long-term studies that are ongoing with defined sampling intervals. The tree demography and census study consists of trees census every two years and seeds collected ~5 x each year.

Examining the potential effects of phytophagous insect frass on forest nitrogen cycling at the Coweeta Hydrologic Laboratory from 1999 to 2001

Human alteration of the global nitrogen cycle has increased the importance of understanding the major sources, sinks, and fluxes of the cycle within natural ecosystems. One poorly understood component of the nitrogen cycle in forest ecosystems is the contribution of phytophagous insect frass on soil N-cycling dynamics. This study proposes to investigate the influence of frass on (1) the dynamics of soil N-cycling; (2) the loss of N from the ecosystem via leaching; (3) the slow cycle decomposition of post-herbivore leaf litter; and (4) the overall potential of soil near the Coweeta Hydrologic Laboratory to retain nitrogen. Red Oak (Quercus rubra [Fagaceae]) saplings will be subjected to defoliation by the seasonal phytophagous insect larvae of the White-Marked Tussock Moth (Orgyia leucostigma [Lepidoptera: Lymantriidae]) and the frass added to the soil in a factorial, controlled experimental design. Soil nutrient concentrations, leachate nutrient concentrations, "soil" respiration, and leaf quality will be measured. The project is expected to increase our understanding of the complex relationship between above-ground and below-ground nitrogen cycling dynamics as well as inform the current debate concerning the relative impacts and importance of human versus natural alterations to the nitrogen cycle.

Summary of lysimeter ion concentrations at Coweeta Watershed One at the Coweeta Hydrologic Laboratory from 1985 to 1988

None provided by researcher.

Bulk throughfall at Coweeta White Pine, Watershed One at the Coweeta Hydrologic Laboratory from 1985 to 1988

None provided by researcher.