Total soil cations (Al, Ca, K, Mg, Na, P) for intertussock O and B horizon soils on moist acidic and non-acidic tundra.
Data Set Results
Extractable soil cations (K, Ca, Mg, Na) for intertussock O and B horizon soils on moist acidic and non-acidic tundra.
Quadrats were harvested for aboveground biomass from eight plots within a tussock, watertrack, and snowbed community at 3 sites - acidic tundra near Toolik (site of acidic LTER plots), nonacidic tundra near Toolik Lake(site of non-acidic LTER plots), and acidic tundra near Sagwon. All vascular species were sorted, divided into new and old growth, dried, and weighed. Lichens were separated by genus in all quadrats. In half of the quadrats (n=4), mosses were separated by species. Moss and lichen data are presented by species elsewhere (see 97lgmosslichen.txt).
Phenological stages of sedges were observed at a long term experimental moist tussock tundra site and a long-term experimental wet sedge tundra sites near Toolik Lake, AK. Also, ITEX maximum growth measurements were recorded on August 19th (moist tussock tundra). Experimental treatments at each site included factorial NxP, greenhouse and shadehouse and were begun in 1989. See 96gsphdc.html and 96gsphsg.html for phenological data on deciduous and evergeen species.
A harvest was conducted to determine productivity of rare species not found in at least 4 quadrats per site in a separate small quadrat aboveground biomass harvest (see 97lg3sbm.txt). Harvests occurred in a tussock, watertrack, and snowbed community at 3 sites - acidic tundra near Toolik (site of acidic LTER plots), nonacidic tundra near Toolik Lake(site of non-acidic LTER plots), and acidic tundra near Sagwon. Moss and lichen data are presented by species elsewhere (see 97lgmosslichen).
To determine temporal and spatial patterns in arctic stream biogeochemistry we conducted three synoptic surveys of streams throughout a 48km2 watershed near Toolik Lake, AK in spring (early-June), summer (mid-July), and fall (mid-September) 2011. During each synoptic survey, we sampled 52 sites within a period of four days to minimize the effect of temporal hydrologic variability. At each site we measured stream temperature, pH, and conductivity and sampled water for solute analysis.
Lake trout were analysed for carbon and nitrogen stable isotope values in 6 Arctic lakes near Toolik Lake at the Arctic LTER in 1987 and 1988. The fish were also analysed for age using otoliths.
Pool size and d15N values for chloroform-extractable N, extractable-N, and non-extractable N pools. Samples collected in Aug. 2003 from 1st Organic Layer of 15N addition plots in Imnavait watershed.
1st Organic Layer = the upper 10 cm of organic soil or, if the organic layer was < 10 cm thick, the entire layer (e.g., there was never > 4 cm of organic soil at Crest).
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.
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 chlorophyll a and primary production in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 1983 to 1989. Sample site descriptors include an assigned number (sortchem), site, date of analysis (incubation), time, depth and rates of primary production. The amount of chlorophyll a and pheophytin were also measured.
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.
Decadal file describing the chlorophyll a and primary production in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 2010 to 2020. Sample site descriptors include an assigned number (sortchem), site, date of analysis (incubation), time, depth and rates of primary production. The amount of chlorophyll a and pheophytin were also measured.
Decadal file describing the chlorophyll a and primary production in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 1990 to 1999. Sample site descriptors include an assigned number (sortchem), site, date of analysis (incubation), time, depth and rates of primary production. The amount of chlorophyll a and pheophytin were also measured.
Output data sets of the MBL-GEM III model for a typical tussock-tundra hill slope. The model is described in two papers:
Le Dizès, S., Kwiatkowski B.L., Rastetter E.B., Hope A., Hobbie J.E., Stow D., Daeschner S., 2003 Modelling biogeochemical responses of tundra ecosystems to temporal and spatial variations in climate in the Kuparuk River Basin (Alaska), Journal of Geophysical Research Vol. 108 No. D2 10.1029/2001JD000960.
Output data set of the MBL-GEM III model run for tussock tundra in the Kuparuk River Basin, Alaska, described in detail in Le Dizès, S., B. L. Kwiatkowski, E. B. Rastetter, A. Hope, J. E. Hobbie, D. Stow, and S. Daeschner, Modeling biogeochemical responses of tundra ecosystems to temporal and spatial variations in climate in the Kuparuk River Basin (Alaska), J. Geophys. Res., 108(D2), 8165, doi:10.1029/2001JD000960, 2003.
Water chemistry (NO3, NH4, TDN, DON, DOC) from Imnavait watershed along hillslope. Sample waters were either collected by lysimeters, needle with syringe, or extracting soil with water or 1N KCl.
Decadal file describing the chlorophyll a and primary production in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 2000 to 2009. Sample site descriptors include an assigned number (sortchem), site, date of analysis (incubation), time, depth and rates of primary production. The amount of chlorophyll a and pheophytin were also measured.
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
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.
Climate change is increasing extreme weather events, but effects on high-frequency weather variability and the resultant impacts on ecosystem function are poorly understood. We assessed ecosystem responses of arctic tundra to changes in day-to-day weather variability using a biogeochemical model and stochastic simulations of daily temperature, precipitation, and light. Changes in weather variability altered ecosystem carbon, nitrogen, and phosphorus stocks and cycling rates.
Climate change is increasing extreme weather events, but effects on high-frequency weather variability and the resultant impacts on ecosystem function are poorly understood. We assessed ecosystem responses of arctic tundra to changes in day-to-day weather variability using a biogeochemical model and stochastic simulations of daily temperature, precipitation, and light. Changes in weather variability altered ecosystem carbon, nitrogen, and phosphorus stocks and cycling rates.