Percent moisture, bulk density, percent loss on ignition and percent organic carbon were measured for peat collected from soils in the Imnavait Creek watershed.
Data Set Results
In arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance and height of deciduous shrubs.
These data are from two remote field campaigns in the Noatak National Preserve. Various thermokarst features and their receiving streams were sampled and characterized. A suite of water chemistry (nutrients, major anions and cations, total suspended sediment) and benthic variables (particulate carbon, nitrogen and phosphorus, and chlorophyll-a) were measured at 6 major sites (2 in 2010 and 4 in 2011). There were additional sites sampled for water chemistry above and below thermokarst features in 2011.
Water samples were taken at 5 locations at both I-Minus2 and Toolik River thermokarst sites (10 sampling locations total). A combination of ISCO and manual grab samples were taken depending on the sampling location and year.
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.
The Changing Seasonality of Arctic Stream Systems (CSASN) was active from 2010 to 2012. The CSASN goal was to quantify the relative influences of through flow, lateral inputs, and hyporheic regeneration on the seasonal fluxes C, N, and P in an arctic river network, and to determine how these influences might shift under seasonal conditions that are likely to be substantially different in the future. During the project, well and mini-piezometer samples were collected from various depths near stream channels and analyzed for a variety of nutrients.
The Changing Seasonality of Arctic Stream Systems (CSASN) was active from 2010 to 2012. The CSASN goal was to quantify the relative influences of through flow, lateral inputs, and hyporheic regeneration on the seasonal fluxes C, N, and P in an arctic river network, and to determine how these influences might shift under seasonal conditions that are likely to be substantially different in the future. During the project, background samples were collected from four stream channels and analyzed for a variety of nutrients.
A spectrophotometer was used to scan the canopy vegetation at four sites along Imnavait Creek in the Kuparuk Watershed near Toolik Lake LTER, Alaska. The resulting reflectance spectra were used to calculate average vegetation indices for each site and collection day.
Vegetation indices calculated from reflectance spectra collected at Arctic LTER experimental plots at Toolik Lake, Alaska during the 2007-2019 growing seasons.
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.
A spectrophotometer was used to scan the canopy vegetation of ITEX harvest plots. The resulting reflectance spectra were used to calculate several vegetation indices of interest (NDVI, EVI, EVI2, PRI, WBI, Chlorophyll Index). Average values of these vegetation indices for each ITEX harvest plot are presented here. These plots also had biomass harvests performed and were analyzed for leaf area and nitrogen content (see 2003-2009gsharvest.csv, 2003-2009gsharvestLAI-N.csv).
Decadal file describing the physical lake parameters recorded at various lakes near Toolik Research Station during summers from 1975 to 1989. Depth profiles at the sites of physical measures were collected in situ. Values measured included temperature, conductivity, pH, dissolved oxygen, Chlorophyll A, Secchi disk depth and PAR. Note that some sample depths also have additional parameters measured and available in separate files for water chemistry and primary production.
Average conductivity of the epilimnion (0-3m of water depth) found in Toolik Lake during the month of July.
Physical (bulk density, soil thickness) and chemical (total C and N, d13C and d15N) information of soil cores taken from 15N addition plots in Imnavait watershed.
Decadal file describing the physical/chemical values recorded at various lakes near Toolik Research Station during summers from 2000 to 2009. Sample site descriptors include site, date, time, depth. Depth profiles of physical measures collected in situ with Hydrolab Datasonde in the field include temperature, conductivity, pH, dissolved oxygen in both percent saturation and mg/l, SCUFA chlorophyll-a values in both volts and µg/l, and PAR.
Decadal file describing the physical/chemical values recorded at various lakes near Toolik Research Station during summers from 1990 to 1999. Sample site descriptors include site, date, time, depth. Depth profiles of physical measures collected in situ with Hydrolab Datasonde in the field include temperature, conductivity, pH, dissolved oxygen in both percent saturation and mg/l, SCUFA chlorophyll-a values in both volts and µg/l, and PAR.
Decadal file describing the physical/chemical values recorded at various lakes near Toolik Research Station. Sample site descriptors include site, date, time, depth. Depth profiles of physical measures collected in situ with Hydrolab Datasonde in the field include temperature, conductivity, pH, dissolved oxygen in both percent saturation and mg/l, SCUFA chlorophyll-a values in both volts and µg/l, and PAR.
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).
Nitrogen mineralization was determined on LTER and Sag River tussock tundra using the buried bag method. Yearly bags have been deployed every August since 1990.
A spectrophotometer was used to scan the canopy vegetation of ITEX flux plots. The resulting reflectance spectra were used to calculate several vegetation indices of interest (NDVI, EVI, EVI2, PRI, WBI, Chlorophyll Index). Average values of these vegetation indices for each ITEX flux plot are presented here.
Quantum yield of Photosystem II estimated from chlorophyll fluorescence of Eriophorum vaginatum leaves from tussocks in the reciprocal transplant gardons at Toolik Lake, Coldfoot, and Sagwon in 2016. A single transplant tussock per plot was repeatedly measured through the season.
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
Dissolved organic carbon (DOC) was leached from permafrost soils near the Toolik Field Station in the Alaskan Arctic and then characterized for its photochemical properties. Oxygen (O2) consumed from photo-oxidation of permafrost DOC was measured as a function of sunlight wavelength, defined as the apparent quantum yield spectrum of photo-oxidation (O2 consumed per mol photon absorbed by DOC). Carbon dioxide (CO2) produced from photomineralization of permafrost DOC was measured as a function of sunlight wavelength, defined as the apparent quantum yield spectrum of photomineralization (CO2
Dissolved organic carbon (DOC) was leached from permafrost soils near the Toolik Field Station in the Alaskan Arctic and then characterized for its photochemical properties. The radiocarbon (14C) and stable carbon (13C) isotopic compositions of carbon dioxide (CO2) photochemically produced from permafrost DOC were quantified.
Dissolved organic carbon (DOC) was leached from permafrost soils collected from the frozen permafrost layer at five sites underlying moist acidic tussock or wet sedge vegetation, and on three glacial surfaces on the North Slope of Alaska during summer 2018.
Dissolved organic carbon (DOC) was leached from permafrost soils near the Toolik Field Station in the Alaskan Arctic and then characterized for its photochemical properties. The apparent quantum yield of photomineralization (photochemical carbon dioxide, CO2, production) of permafrost DOC was quantified at 309 nm.
Soil temperatures at 2 depths, 5 and 10 cm, canopy temperatures and soil moisture at 10 cm were measured in a heath tundra Arctic Long Term Experimental Research (ARC-LTER) site at Toolik Lake Field Station, North slope, Alaska. Air temperature and relative humidity and global radiation were also measured but are presented in another dataset. Only control and nutrient addition (nitrogen plus phosphorus ) treatments plots were measured .