Invertebrates (spiders, insects and slugs) were collected weekly using pitfall traps at four sites near the Arctic LTER at Toolik Field Station, Alaska. Traps were placed along transects in shrub (shrub-dominant) and open (tussock-dominant) tundra sites. Pitfall traps were placed for 48-hour intervals once per week from early June until mid-July 2010. Collected invertebrates were counted and identified to class (all invertebrates), order or family (for some of the most common families collected).
Data Set Results
Above ground plant and below ground stem biomass, percent nitrogen, and percent carbon were measured in the Arctic LTER moist acidic tundra experimental plots. Treatments included control, and nitrogen and phosphorus amended plots for 10 years, and exclosure plots with and without added nitrogen and phosphorus.
In 2011, relative percent cover of plant species was measured in LTER moist acidic tundra experimental plots and in new experimental plots established in 2006.
In 2010, thaw depth and soil temperature were measured throughout the growing season in control and fertilized plots in the Arctic LTER's moist acidic tundra sites.
Weekly growth of plant species of three growth forms were measured in the ninth year of a long-term experiment at Toolik Field Station. The experimental treatments excluded small and large mammalian herbivores and increased soil nutrients in two arctic Alaskan tundra communities: moist acidic tussock and dry heath. This data set reports the deciduous dwarf shrub species. Please see 2004lggrgram for the tussock-forming and rhizomatous graminoid species growth data.
Above ground plant and below ground stem biomass, percent nitrogen, and percent carbon were measured in the Arctic LTER dry heath tundra experimental plots. Treatments included control, and nitrogen and phosphorus amended plots for 10 years, and exclosure plots with and without added nitrogen and phosphorus.
The abundance and dry biomass of canopy-dwelling arthropods (insects and small spiders) was tracked over five summers (2010-2014) at four sites near Toolik Field Station, Alaska. At each site, a shrub-dominant and tussock-tundra habitat was chosen for sampling, for a total of 8 sampling locations. At each sampling location, a 100-meter transect was established. Arthropods were sampled along the transect weekly by passing a sweepnet through and over the vegetation. After killing the arthropods with pest strips and freezing, they were sorted from the associated leaf litter and counted.
In 2010, Relative percent cover of plant species was measured in the Arctic LTER's experimental and control plots across several habitats: moist acidic, dry heath, and moist non-acidic tundra; in new variable (low) nutrient addition experimental plots established in 2006; and for Sagavanirktok River toposequence plots in tussock and heath tundra.
Relative percent cover was measured for plant species on Arctic LTER experimental plots at Toolik field station in moist acidic tussock and dry heath tundra.
In 2008, Relative percent cover of plant species was measured in the Arctic LTER's experimental and control plots across several habitats: moist acidic, dry heath, and moist non-acidic tundra; in new variable (low) nutrient addition experimental plots established in 2006; and for Sagavanirktok River toposequence plots in tussock and heath tundra.
Weekly growth of plant species of three growth forms were measured in the ninth year of a long-term experiment at Toolik Field Station. The experimental treatments excluded small and large mammalian herbivores and increased soil nutrients in two arctic Alaskan tundra communities: moist acidic tussock and dry heath. This data set reports the four graminoid (both tussock and rhizomatous forms) species. Please see 2004lggrbnan for Betula nana (dwarf shrub) growth data.
Relative percent cover was measured for plant species on Arctic LTER experimental plots at Toolik field station in moist acidic and moist non acidic tussock tundra, and dry heath tundra, and on Sagavanirktok River toposequence plots in tussock and heath tundra.
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.
Relative percent cover was measured for plant species on Arctic LTER experimental plots at Toolik field station in moist acidic and moist non acidic tussock tundra, and dry heath tundra, and on Sagavanirktok River toposequence plots in tussock and heath tundra.
Relative percent cover was measured for plant species on Arctic LTER experimental plots in moist acidic and moist non-acidic tundra, Toolik Field Station, Alaska, Arctic LTER 1999.
Above ground plant and belowground stem biomass was measured in moist acidic and non-acidic tussock tundra experimental sites. Treatments sampled were control plots and plots amended with nitrogen and phosphorus.
Relative percent cover was measured for plant species on Arctic LTER experimental plots at Toolik field station in moist acidic and moist non acidic tussock tundra, and dry heath tundra.
Percent carbon, percent nitrogen, del13C and del15N were measured from above ground plant and belowground stem biomass samples from experimental plots in moist acidic and moist non-acidic tundra. Biomass data are in 2000lgshttbm.dat.
Relative percent cover was measured for plant species on Arctic LTER experimental plots in moist acidic and moist non-acidic tundra.
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.
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).
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).
Relative percent cover was measured for plant species on Arctic LTER experimental plots in moist acidic and moist non-acidic tundra.
Percent carbon and percent nitrogen were measured from above ground plant and belowground stem biomass samples from experimental plots in moist acidic and moist non-acidic tundra. Biomass data are in 2001lgshttbm.dat.
Aboveground plant and belowground stem biomass were measured in moist acidic and moist non-acidic tussock tundra experimental plots. Treatments at the acidic site include control and nitrogen (N) plus phosphorus (P) amendments; treatments at the non-acidic site include N, P, N+P, greenhouse warming, and greenhouse+N+P.
Note: Version 8 corrected an error where Carex vaginata was listed twice under treatment of "Nitrogen Phosphorus". The tissues with 8 quadrats were "Greenhouse" treatment.
Relative percent cover was measured for plant species on Arctic LTER experimental plots in moist acidic and moist non-acidic tundra.
Relative percent cover of plant species was measured in low nutrient LTER moist acidic tundra experimental plots (MAT06). Treatments include a gradient of nitrogen and phosphorus additions along with ammonium and nitrate alone.
Relative percent cover of plant species was measured in moist acidic tundra experimental plots begun in 1981 in 2014. Treatments include Control and Nitrogen and Phosphorus.
Relative percent cover of plant species was measured in Arctic Long-Term Ecological Research (ARC-LTER) Dry Heath experimental plots. Treatments include Nitrogen Phosphorus (NP), and Control (CT), Nitrogen Phosphorus Unfenced (NFNP), Nitrogen Phosphorus Small Fenced (SFNP), Nitrogen Phosphorus Large Fenced (LFNP), Control (CT), Control Small Fenced (CTSF), and Control Large Fenced (LFCT).
Relative percent cover of plant species was measured in ARC-LTER 1989 moist acidic tundra experimental plots. Treatments include Control (CT), Nitrogen Phosphorus (NP), Nitrogen (N), Phosphorus (P), and Greenhouse Control (GHCT). In 1996 on unassigned plots, an experiment that manipulate herbivory presence and nutrients was started. Treatments include Control Unfenced (NFCT), Nitrogen Phosphorus Unfenced (NFNP), and Small Fenced Control (CTSF). Not all treatments were measured each year.
We use a simple model of coupled carbon and nitrogen cycles in terrestrial ecosystems to examine how explicitly representing grazers versus having grazer effects implicitly aggregated in with other biogeochemical processes in the model alters predicted responses to elevated carbon dioxide and warming. The aggregated approach can affect model predictions because grazer-mediated processes can respond differently to changes in climate from the processes with which they are typically aggregated.
We use a simple model of coupled carbon and nitrogen cycles in terrestrial ecosystems to examine how explicitly representing grazers versus having grazer effects implicitly aggregated in with other biogeochemical processes in the model alters predicted responses to elevated carbon dioxide and warming. The aggregated approach can affect model predictions because grazer-mediated processes can respond differently to changes in climate from the processes with which they are typically aggregated.
Tillers from 24 Eriophorum vaginatum individuals were sampled in late July 2019 to examine differences in percent nitrogen between previously burned (Anaktuvuk River Fire) and unburned tussocks at a nearby unburned control site. At the burned site tussocks exhibiting evidence of rodent grazing were also sampled to separate herbivore effects from those of the fire. From each tussock, 3-4 new leaves were sampled (as indicated by lack of brown tips) and dried at 60°C for 24 hours, before being ground and analyzed for percent nitrogen.
Percent cover of tundra vole and brown lemming structures collected from within the Team Vole enclosure/exclosure fences near Nome, Toolik, Utqiagvik, AK 2019.