In 1980-1982, six transplant gardens were established along a latitudinal gradient in interior Alaska from Eagle Creek, AK, in the south to Prudhoe Bay, AK, in the north (Shaver et al. 1986) .Three sites, Toolik Lake (TL), Sagwon (SAG), and Prudhoe Bay (PB) are north of the continental divide and the remaining three, Eagle Creek (EC), No Name Creek (NN), and Coldfoot (CF), are south of the continental divide. Each garden consisted of 10 individual tussocks transplanted back to their home-site, as well as 10 individuals from each of the other transplant sites.
Data Set Results
Data file describing the bacterial production and bacterial respiration of water samples collected at various sites near Toolik Lake on the North Slope of Alaska. Sample site descriptors include site, date, time, depth, and category representing severity of thermokarst disturbance. A synthesis of the data presented here is published in Cory et al. 2013, PNAS 110:3429-3434, and in Cory et al. 2014, Science 345:925-928.
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. Point transects were done throughout the sampling season to determine different substrate and cover types on the stream bottom.
A spectrophotometer was used to scan the canopy vegetation at four sites near Imnavait Creek each year from 2008 - 2010 by Toolik Lake LTER, Alaska. Reflectance spectra from 310-1130 nm are presented here with information relating the date and site of the scan.
Stems were measured, and aged from Ledum palustre and Salix pulchra species on treated plots at Toolik Lake, AK. Stem secondary growth in per cent per year was estimated from the slope of weight per unit length vs. age.
Seasonal patterns of leaf exsertion, elongation and senescence for Eriophorum vaginatum and Carex bigelowii was measured in mesic tussock tundra sites near Toolik Lake, AK. In addition, the response of both species to NP fertilizer and to variation in site fertility (after track versus non-track areas) were also assayed and compared. The research was done over two full growing seasons.
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).
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.
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.
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.
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.
Arctic Grayling were collected at designated stations on the Oksrukuyik from 1990 to current time. Phosphorus addition has occurred from 1991 to 1996; station sites are relative distance from the original 1991 dripper. Grayling were caught, pit tagged, weighed, measured, and then released back into the river.
Adult Arctic Grayling were caught and tagged in the Kuparuk River. A second fishing campaign occurred later in the summer, and any fish that was recaptured was remeasured to determine growth. Phosphorus addition has occurred since 1983; station sites are relative distance from the original 1983 phosphorus dripper. Stations include sites in a reference, recovery, and fertilized reach. Reaches were defined based on the location of phosphorous addition (see methods). Arctic Grayling were caught early in the field season, tagged, and recaptured late in the field season.
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. Fish were collected on each river. Station locations, representing kilomter values certain distances from original phosphorus dripper (see method) were noted.
This file contains the consolidated data for percent cover of dominant bryophytes and other easily identifiable macro-algae in the experimental reaches of the Kuparuk River beginning in 1993 and updated annually. In some years percent cover was recorded more than one time per season. In all years percent cover was recorded in riffle habitats and in some (early) years percent cover was recorded for pool habitats. Moss point transects have been done on the Kuparuk since 1993.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.
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.
From 2009 to 2017, the FISHSCAPE Project (grant numbers 1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biological parameters within three watersheds: The Kuparuk (including Toolik Lake and Toolik outlet stream); The Sagavanirktok (primarily Oksrukuyik Creek, but also including sections of the Ailish and Atigun Rivers and the Galbraith Lakes); and The Itkillik (primarily the I-Minus outlet stream, a tributary that that feeds into the Itkilik River).
Since 2009, the FISHSCAPE Project (grant number 1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biolog
Since 2009, the FISHSCAPEÂ Project (Grant #1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biological parameters within three watersheds: The Kuparuk (including Toolik Lake and Toolik outlet stream); The Sagavanirktok (primarily Oksrukuyik Creek, but also including sections of the Ailish and Atigun Rivers and the Galbraith Lakes);Â and The Itkillik (primarily the I-Minus outlet stream, a tributary that that feeds into the Itkilik River).
Since 2009, the FISHSCAPEÂ Project (grant #Â 1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biological parameters within three watersheds: The Kuparuk (including Toolik Lake and Toolik outlet stream); The Sagavanirktok (primarily Oksrukuyik Creek, but also including sections of the Ailish and Atigun Rivers and the Galbraith Lakes);Â and The Itkillik (primarily the I-Minus outlet stream, a tributary that that feeds into the Itkilik River).
Since 2009, The FISHSCAPE Project (National Science Foundation grants: 1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biological parameters within three watersheds: The Kuparuk (including Toolik Lake and Toolik outlet stream), The Sagavanirktok (primarily Oksrukuyik Creek, but also including sections of the Atigun River and Tea and Galbraith Lakes), and Itkillik (primarily the I-Minus outlet stream a tributary that that feeds into the Itkilik River). Goals of the FISHSCAPE project are to understand and predict the adaptability and persi
File containing data on bacterial productivity in lakes and streams. Samples were collected at various sites near Toolik Lake Field Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth, and bacterial production.  Â
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.
This dataset consists of tussock density, mortality rates and causes, and an assesment of rodent-herbivore activity levels in previously burned (2007 Anaktuvuk River fire) and unburned tussock tundra. Eriophourm vaginatum tussocks were counted every meter within a 1 square meter quadrat along three transects. Cause of tussock mortality, as well as level of rodent herbivory was assessed for each tussock, and rodent herbivore activity was assessed for each quadrat.
Small mammals (rodents and shrews) were sampled 7-12 years following the Anaktuvuk River Fire to examine how post-fire ecological changes influence small mammal abundance. Small mammals were snap-trapped in August 2014, 2017-2019 at the site of the 2007 Anaktuvuk River Fire, and a nearby unburned control site. At each site, 120 traps were set in 3 parallel lines spaced 40m apart. Each trap was spaced 10m apart, baited, and set to rodent sign within one meter of the trap station. Traps were checked the following two mornings with all captures collected and sprung traps reset.
This file contains biomass measurements from vole-grazed and ungrazed Eriophorum vaginatum tussocks taken from the 2007 Anaktuvuk River Fire scar in 2019. Rodent-grazed and ungrazed tussocks were harvested to assess the impact voles have on biomass. Eighteen grazed tussocks and seven ungrazed tussocks were harvested and taken back to the lab. Ungrazed tussocks were subsampled to make seperation faster. Eight additional ungrzed tussocks were measured in the field and biomass estimates were made using allometry equations based on diameter.