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
Data Set Results
Phenological stages of evergeen plants were observed at a long term experimental moist acidic tussock tundra (Arctic LTER) in 1996 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 and 96gsphsg for phenological data on deciduous and sedge species.
Vegetation indices calculated from reflectance spectra collected at Arctic LTER experimental plots at Toolik Lake, Alaska during the 2007-2019 growing seasons.
Vascular plant species list, by quadrat, for harvests of tussock tundra, wet sedge tundra, dry heath tundra, and a toposequence which also included "shrub/lupine," "riverside willow" and "footslope Equisetum" communities. Includes results of long-term nutrient enrichment, increased temperature, and shade houses in selected tundra types.
Late season thaw depth was measured in the Arctic Long Term Ecological Research (ARC LTER) experimental plots (1981 Moist Acidic Tussock, 1989 Moist Acidic Tussock, 2006 Low Fertilization Moist Acidic Tussock, 1989 Moist Non-acidic Tussock, 1989 Moist Non-acidic Non-tussock and 1989 Wet Sedge tundra) at Toolik Lake, Alaska using a steel thaw probe. Note: for 2017-2018 only 1989 Moist Non-Acidic Tussock Tundra and 2006 Low fertilization Moist Acidic Tussock Tundra were measured. For other sites it has become difficult to distinguish rocks from frozen soil with a steel thaw probe.
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.
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).
Above ground plant and below ground stem biomass was measured in Arctic LTER tussock tundra experimental small mammal exclosures. Treatments included Control, Nitrogen plus Phosphorus with both fenced and unfenced plots. In addition a moist non-acidic tussock tundra site was harvested. Leaf areas were also measured for each quadrat but are in a separate file.
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).
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.
GPS locations and vegetation descriptions for the ITEX flux survey plots. Survey plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Foliar carbon and nitrogen concentrations of the dominant species from within the ITEX flux survey plots 2003-2004. Plots were located in the Toolik Lake LTER moist acidic tussock experiment plots in Alaska; at Imnavait Creek, Alaska.
This data file contains the data on weights and lengths from retrospective growth analysis of different stem age classes of Betula nana ramets from the Arctic LTER Nutrient and Warming manipulations in moist acidic tussock tundra at Toolik Lake.
This data file contains the data on weights and lengths from retrospective growth analysis of different stem age classes of Betula nana ramets from the LTER Nutrient and Warming manipulations in tussock tundra at Toolik Lake.
Soil temperature, moisture content and thaw depth of the ITEX flux survey plots. Survey plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Leaf area, biomass, foliar carbon and nitrogen by species for destructive vegetation harvests. Plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; and at various sites in Adventdalen, Svalbard, in Zackenberg valley, Northeast Greenland, and at BEO near Barrow, Alaska. Harvests were taken during the growing seasons 2003 to 2009.
A list of plant species encountered during the ITEX flux survey, with their corrresponding 6 letter codes and functional groups. Research sites were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Data was collected during the growing seasons 2003 to 2006.
Estimated aerial plant % cover by functional type in flux plots measured during the ITEX cirumarctic flux survey 2004-2006. Survey plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Ecosystem CO2 flux light response curves were measured on 1m x 1m plots ( some 0.3m x 0.3m plots in 2006 and some 0.7m x0.7m plots in 2009) across the arctic. This file contains the best fit parameters that describe these light response curves, together with corresponding NDVI data for each curve.
Leaf area, biomass, foliar carbon and nitrogen by species for destructive vegetation harvests. Plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; and at various sites in Adventdalen, Svalbard, in Zackenberg valley, Northeast Greenland and at BEO near Barrow, Alaska. Harvests were taken during the growing seasons 2003 to 2009.
Ecosystem CO2 flux light response curves were measured on 1m x 1m plots across the arctic. This file contains the CO2 and H2O flux measurements and NDVI data for each plot. Survey plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Estimated aerial plant % cover by species in flux plots measured during the ITEX circumarctic flux survey 2004-2006. Flux plots were located in the Toolik Lake LTER fertilization experiment in Alaska; at Imnavait Creek, Alaska; at Paddus, Latnjajaure and the Stepps site near Abisko in northern Sweden; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska.
Numbers of Eriophorum vaginatum inflorescences, both unclipped and clipped by small mammals, were counted in experimental plots. The plots are setup in moist acidic tussock tundra near Toolik Field Station, Alaska ((8 degrees 37' 27" N, 149 degrees 36' 27"W) and include fenced exclosures in both fertilized and unfertilized tundra.
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.
Phenological stages of deciduous plants were observed at a long term experimental moist acidic tussock tundra site (Arctic LTER) near Toolik Field Station, 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 96gspheg.html and 96gsphsg. html for phenological data on evergreen and sedge species.
Methane and carbon dioxide emissions were monitored in control, greenhouse, and nitrogen and phosphorus fertilized plots of three different plant communities. This is the third year of collection data.
Methane and carbon dioxide emissions were monitored in control, greenhouse, and nitrogen and phosphorus fertilized plots of three different plant communities. This is the second year of collection data.
Methane and carbon dioxide emissions were monitored in control, greenhouse, and nitrogen and phosphorus fertilized plots of three different plant communities.
Above ground plant and below ground stem biomass was measured in the Arctic LTER acidic tussock tundra experimental plots. Treatments included control, nitrogen plus phosphorus amended plots for either 6 or 13 years and vole exclosure plots with or without amends of nitrogen and phosphorus.
Leaf areas were measured on quadrats harvested in Arctic LTER tussock tundra experimental small mammal exclosures. Treatments included Control, Nitrogen plus Phosphorus with both fenced and unfenced plots. In addition a moist non-acidic tussock tundra site was harvested. Biomass was also measured for each quadrat but is in a separate file.
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.
Hourly weather data from the LTER Moist Acidic Tussock Experimental plots. The station was installed in 1990 in block 2 of the Toolik LTER experimental moist acidic tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Global solar radiation, photosynthetic active radiation, unfrozen precipitation, air temperature, relative humidity, wind speed, and wind direction are measured at 3 meters. Additional sensors in greenhouses and shade houses plots measure air temperature, relative humidity and photosynthetic active radiation during the growing season.
Hourly weather data from the LTER Moist Acidic Tussock Experimental plots. The station was installed in 1990 in block 2 of the Toolik LTER experimental moist acidic tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Global solar radiation, photosynthetic active radiation, unfrozen precipitation, air temperature, relative humidity, wind speed, and wind direction are measured at 3 meters.
Soil and canopy temperature data from the LTER Moist Acidic Tussock Experimental plots. In 1989 a treatment plots were established in a moist acidic tundra. Treatments include nitrogen and phosphorus addition, warming with a simple greenhouse, warming with nitrogen and phosphorus addition, shading with shade cloth and shading with nitrogen and phosphorus. In 1990 data logger was installed in block 2 to measure soil temperatures and basic meteorological data. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W).
Daily weather and soil temperature data from the Toolik Tussock Experimental plots. In 1990 a Campbell CR21X data logger was installed in block 2 of the Toolik LTER experimental tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in a control, fertilized, greenhouse, greenhouse fertilized, shade house and shade house fertilized plots.
Daily summary of 10 cm soil temperatures in the Arctic LTER moist acidic experimental plots for the control (CT), greenhouse (GH), greenhouse plus nitrogen and phosphorus (GHNP) and nitrogen and phosphorus (NP) plots. Soil temperature probes in the tundra soil were problematic with frost heaving causing the depth of measurements to change. In order to provide a consistent year to year temperature record notes on changes in depths were used to select the temperature sensor that was within + or – 3 cm of the 10 cm and then averaged daily.
Daily weather and soil temperature data from the Toolik Tussock Experimental plots. In 1990 a Campbell CR21X data logger was installed in block 2 of the Toolik LTER experimental tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in a control, fertilized, greenhouse, greenhouse fertilized, shade house and shade house fertilized plots.
Soil temperature data from the Arctic LTER Toolik Tussock Experimental plots. In 1990 a Campbell CR21x datalogger was installed in block 2 of the Toolik LTER experimental tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in a control, fertilized, greenhouse, greenhouse fertilized, shadehouse and shadehouse fertilized sites.
Soil and canopy temperature data from the LTER Moist Acidic Tussock Experimental plots. In 1989 a treatment plots were established in a moist acidic tundra. Treatments include nitrogen and phosphorus addition, warming with a simple greenhouse, warming with nitrogen and phosphorus addition, shading with shade cloth and shading with nitrogen and phosphorus. In 1990 data logger was installed in block 2 to measure soil temperatures and basic meteorological data. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W).
Soil temperature data from the Toolik Tussock Experimental plots. In 1990 a Campbell CR21x datalogger was installed in block 2 of the Toolik LTER experimental tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in a control, fertilized, greenhouse, greenhouse fertilized, shade house and shade house fertilized sites.
Hourly weather data from the LTER Moist Acidic Tussock Experimental plots. The station was installed in 1990 in block 2 of the Toolik LTER experimental moist acidic tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Global solar radiation, photosynthetic active radiation, unfrozen precipitation, air temperature, relative humidity, wind speed, and wind direction are measured at 3 meters.
Soil temperature data from the Toolik Tussock Experimental plots. In 1990 a Campbell CR21X datalogger was installed in block 2 of the Toolik LTER experimental tussock plots. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Sensors were placed in a control, fertilized, greenhouse, greenhouse fertilized, shade house and shade house fertilized plots. All soil sensors are read every 15 minutes and averaged every 3 hours.
Soil and canopy temperature data from the Arctic LTER 1989 Moist Acidic Tussock Experimental plots(MAT89). The station was established in 1990 in block 2 of a 4 block random block design. The plots are located on a hillside near Toolik Lake, Alaska (68 38' N, 149 36'W). Treatments include - control (CT), greenhouse (GH), greenhouse plus nitrogen and phosphorus (GHNP) shade (SH), shade plus nitrogen and phosphorus (SHNP) and nitrogen and phosphorus (NP). Profiles include above and within canopy, 10, 20 and 40 centimeter soil depths. Not all treatments have a complete profile.
Soil temperature data from the 1989 LTER Moist Acidic Tussock (MAT89) Experimental plots. The logging station was installed in 1990 in block 2 of a four block experimental block design. The plots are located on a hillside near Toolik Lake (68 38' N, 149 36'W). Two replicates depth profiles (10, 20 ,40 centimeters) were installed in each block 2 experimental plots. Frost heaving has caused uncertain depths of measurements for many of the profiles. This data set contains only the control profiles from 2008 to 2020.