Data file containing biogeochemical data of water samples collected in Imnavait Creek, North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, distance (downstream), and elevation. Values of variables measured in the field include temperature, conductivity, pH. Chemical analysis for samples include alkalinity, dissolved organic carbon, inorganic and total dissolved nutrients particulate carbon, nitrogen, and phosphorus, cations and anions.
Data Set Results
This file contains data collected from thermokarst impacted soils, lakes, and streams near Toolik Lake Alaska. Data are also presented for experimental manipulations of water (e.g., time course experiments). Sample descriptors include a unique sortchem #, site, date, time, depth, distance, elevation, treatment, date-time, category, and water type (e.g., lake, surface, soil). Physical/chemical measures collected in the field include temperature, conductivity, and pH.
Plant available NH4, NO3, and PO4 was determined at three site (LTER Toolik acidic tundra, LTER Toolik nonacidic tundra, and Sagwon acidic tundra) and three community combinations (tussock, watertrack, and snowbed), three times during the season. pH was also determined in July and strong acid phosphorous in August.
Bulk precipitation was collected during summer months (June, July and August) on a per rain event basis at the University of Alaska Fairbanks Toolik Field Station, North Slope of Alaska (68 degrees 37' 42"N, 149 degrees 35' 46"W). Analysis of pH, NH4-N and phosphorus were performed at the field station. NO3-N were frozen and analyzed in Woods Hole, MA
Plant available NH4, NO3, and PO4 was determined at sites near ARC LTER Toolik acidic tundra and at a toposequence along the floodplain of the Sagavanirktuk River using 2 N KCL and weak HCL extracts. This file complies data collected at different times from 1987 through 2001 and includes initial extracts taken for buried bag method of net nitrogen mineralization.
Precipitation, collected from a wet/dry precipitation collector located near University of Alaska Fairbanks Toolik Field Station, North Slope of Alaska (68 degrees 37' 42"N, 149 degrees 35' 46"W) was sent out for standardized EPA rain water analysis. Nutrient chemistry was also run on a sub sample at the field station.
Inorganic Nitrogen and phosphorus were analyzed on snow samples taken from two snow pits near the long-term acrtic LTER mesic acidic tussock experimental plots. The snow layers in each pit were described and sampled separtely with the help of Matthrew Sturm.
Data file describing the biogeochemistry of samples collected at various sites near Toolik Lake, North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, distance (downstream), elevation, treatment, date-time, category, and water type (lake, surface, soil). Physical measures collected in the field include temperature (water, soil, well water), conductivity, pH, average thaw depth, well height, discharge, stage height, and light (lakes).
Data file describing the biogeochemistry of samples collected at various sites near Toolik Lake, North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, distance (downstream), elevation, treatment, date-time, category, and water type (lake, surface, soil). Physical measures collected in the field include temperature (water, soil, well water), conductivity, pH, average thaw depth, well height, discharge, stage height, and light (lakes).
Since 1983, the Streams Project at the Toolik Field Station has monitored physical, chemical, and biological parameters in a 5-km, fourth-order reach of the Kuparuk River near its intersection with the Dalton Highway and the Trans-Alaska Pipeline. In 1989, similar studies were begun on a 3.5-km, third-order reach of a second stream, Oksrukuyik Creek.
Concentrations of NO3 and NH4 and d15N of NO3 and NH4 collected on resin bags from 15N addition plots along hillslope in Imnavait watershed.
Note: Corrections were made to Particulate phosphorus values. See version 5 notes.
The data set describes stable carbon and nitrogen isotopes and carbon and nitrogen concentrations from an August 2012 pluck of a fertilization experiment begun in 2006. Fertilization was with nitrogen (N) and phosphorus (P). Fertilization levels included control, F2, F5, and F10, with F2 corresponding to yearly additions of 2 g/m2 N and 1 g/m2 P, F5 corresponding to yearly additions of 5 g/m2 N and 2.5 g/m2 P, and F10 corresponding to yearly additions of 10 g/m2 N and 5 g/m2 P. After harvest, plants were separated by species and then by tissue.
Transplant gardens at Toolik Lake and Sagwon were established in 2014. At each location, 60 tussocks each from ecotypes of Eriophorum vaginatum from Coldfoot (CF, 67°15′32″N, 150°10′12″W), Toolik Lake (TL, 68°37′44″N, 149°35′0″W), and Sagwon (SG, 69°25′26″N, 148°42′49″W) were transplanted. At the reciprocal transplant gardens, ion exchange membranes were used to measure nutrient availability over two time periods: Early season (June) and mid season (July). Membranes were deployed in the field for either 20 or 21 days, depending on travel constraints.
Data file of the biogeochemistry of samples collected at various sites near Toolik Lake, North Slope of Alaska. Sample site descriptors include a unique assigned number (sortchem), site, date, time, depth, distance (downstream from a reference location), elevation, treatment, date-time, category, and water type (lake, surface, soil). Physical measures collected in the field include temperature (water, soil, well water), conductivity, pH, and average thaw depth in soil. Chemical analyses for the sample include alkalinity; dissolved inorganic and organic carbon (DIC and DOC); dissolved gas
Data file describing high frequency (every ~10 minutes), optial sensor-derived chemistry of river water from Oksukuyik Creek near Toolik Field Station, North Slope of Alaska. Data file includes date, time, dissolved organic carbon (DOC) concentration, and nitrate concentration. Sensors (V2 s::can uv-vis spectrophotometers) were continuously deployed from June through August or September and optically determined nitrate and dissolved organic carbon concentrations.
Data file describing high frequency (every ~10 minutes), optial sensor-derived chemistry of river water from Trevor Creek near Toolik Field Station, North Slope of Alaska. Data file includes date, time, dissolved organic carbon (DOC) concentration, and nitrate concentration. Sensors (V2 s::can uv-vis spectrophotometers) were continuously deployed from June through August or September and optically determined nitrate and dissolved organic carbon concentrations.
Data file describing repeated sampling of chemistry of distributed river water from the Kuparuk River, Oksrukuyik Creek, and Trevor Creek watersheds near Toolik Field Station, North Slope of Alaska. Data file includes sampling date, season, sampling point, subcatchment area, and resulting concentrations for a suite of solutes.
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation.
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation.