Jennifer D. Knoepp

USDA Forest Service Coweeta Hydrologic Laboratory 3160 Coweeta Lab Road Otto NOrth Carolina 28763 USA

(828) 524-6768 knoepp@sparc.ecology.uga.edu jknoepp@fs.fed http://cwt33.ecology.uga.edu/piprofiles/pro_knoepp.html Examination of N-transformation along elevation and vegetation gradient. These measurements are analysis of plant nitrogen availability and overall site productivity. Potential nitrogen transformation rates (net nitrification and mineralization) are measured using closed core in situ incubations of the 0-10 cm of mineral soil for 28 days. Two cores are driven into the top 10 cm of soil 25 cm apart. One core is removed and represents t=0 NH4+ and NO3- concentrations. The other core is capped with a PVC cap and left in place for 28 days. Incubations are performed at randomly selected points on each of four transects on each LTER plot, these transects are used as replicates. Three sets of nitrogen transformation measurements are conducted on the extensive plots. NH4+- and NO3- nitrogen concentrations are measured in fresh soil sieved (6mm) extracted with 2 M KCl (10 g soil:20 ml KCl) for 1 hour. Coweeta LTER Nitrogen transformation nitrification mineralization Must adhere to the Coweeta LTER Data Policy (See http://coweeta.ecology.uga.edu/webdocs/3/static/datapolicies.html). http://cwt33.ecology.uga.edu/summaries/summary1014.html WS18 and WS27 1991-05-01 1995-01-01 Coweeta LTER Information Manager

Institute of Ecology University of Georgia Athens Georgia 30602 USA

(828) 524-2128 Ted Gragson

Institute of Ecology University of Georgia Athens Georgia 30602 USA

tgragson@earthlink.net principalInvestigator James Vose

Institute of Ecology University of Georgia Athens Georgia 30602 USA

jvose@fs.fed.us principalInvestigator Brian Kloeppel

Institute of Ecology University of Georgia Athens Georgia 30602 USA

kloeppel@sparc.ecology.uga.edu principalInvestigator The Coweeta LTER Research Program has evolved since 1980 from a site-based to a site- and region-based project examining the effects of disturbance and environmental gradients on biogeochemical cycling, and the underlying watershed ecosystem processes that regulate and respond to those cycles. The objective for the 2002-2008 research is to advance scientific understanding of the spatial, temporal, and decision-making components of land use and land-use change in the southern Appalachian Mountains over the last 200 years, and forecast patterns into the future 30 years. This will be accomplished by addressing ecological and socioeconomic aspects of land-use change while continuing long-term studies of environmental gradients and natural disturbance regimes. The result will be a more complete understanding of ecological dynamics in the southern Appalachian Mountains that makes possible the development of reasonable forecasts of its future ecological state. | The guiding hypothesis for the proposed research is that the frequency, intensity, and extent of land use represents human decision-making in response to socioeconomic and bio-geophysical conditions with consequences that cascade through ecosystems. The research activities are organized into three initiatives: (1) Characterization of the Socio-Natural Template, (2) Ecosystem Responses to the Socio-Natural Template, and (3) Forecasting Ecosystem Responses to Changes in the Socio-Natural Template. The integrated scientific research will provide both a description as well as an explanation of the underlying causes of land use and the consequences of land-use change for southern Appalachian ecosystems and society. It thus recognizes the complexity of land use as a process and the research needs as defined in the LTER Program and the broader scientific community. National Science Foundation. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. uid=cwt,o=lter,dc=ecoinformatics,dc=org all public read 1014.csv 1014.csv 1 \n \n column , http://cwt33.ecology.uga.edu/data/1014.csv Site Site site Id site Id . Missing Value Plot Plot plot locations F Forest health monitoring site-527 FR Forest health monitoring site under rhododendron-527 L Litter decomposition site-218 L11 Litter trap-427 P Main Plot T Voses productivity tower-527 and 427 Canopy walkway-218 . Missing Value Sample Sample sampling dates, days of collection ranging from 1 to 19 sampling dates, days of collection ranging from 1 to 19 . Missing Value Nitrif Nitrif net change in soil NO3--N concentration over the 28 day incubation period. net change in soil NO3--N concentration over the 28 day incubation period. . Missing Value D_NH4 D_NH4 net change in soil NH4+-N concentration over the 28 day incubation period. net change in soil NH4+-N concentration over the 28 day incubation period. . Missing Value MIN MIN net change in soil NH4+-N + NO3--N concentration over the 28 day incubation period. net change in soil NH4+-N + NO3--N concentration over the 28 day incubation period. . Missing Value NO3_0 NO3_0 soil NO3--N concentration in t=0 soil collected for N transformation measurements. Analyzed on Technicon using hydrazine reduction. soil NO3--N concentration in t=0 soil collected for N transformation measurements. Analyzed on Technicon using hydrazine reduction. . Missing Value NH4_0 NH4_0 soil NH4+-N concentration in t=0 soil collected for N transformation measurements. Analyzed on Technicon using alkaline phenol method. soil NH4+-N concentration in t=0 soil collected for N transformation measurements. Analyzed on Technicon using alkaline phenol method. . Missing Value