These data were collected in July 2010 for tussocks transplanted in 1980-82 in a reciprocal transplant experiment and harvested in 2011. Important variables are garden name, source population, length and density of stomata, and the temperature of tussocks.
Data Set Results
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.
Del 13C ratios were measured for mosses collected from terrestrial, emergent and submerged sites in pond 13 of Imnavait Creek. Terrestrial mosses were collected from dry sites near the pond margin, emergent mosses were collected from the littoral zone of the pond and submerged mosses were collected from deep in the pond.
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.
This file is from the Long-term Carbon and Nitrogen, and Phosphorus Dynamics of Leaf and Fine Root Litter project (LIDET-Long-term Intersite Decomposition Experiment Team). This file contains only the Arctic LTER data. In particular the mass looses over the ten year study. Three types of fine roots (graminoid, hardwood, and conifer), six types of leaf litter (which ranged in lignin/nitrogen ratio from 5 to 75), and wooden dowels were used for litter incubations over a ten year period.
The data set includes 15N and 13C for plant litter, soil, plants and fungal fruiting bodies (mycorrhizae), percent C (soil organic matter and percent N from samples collected in three separate trips (1990, 2004, 2007) along the transect of the Dalton Highway (AK) extending from the Yukon River on the south to Prudhoe Bay on the north.
Hourly air temperature, humidity, wind speed, soil temperature and soil water data from an unmanipulated shrub patch measured from August 6, 2006 to September 12, 2010.
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.
Leave growth of Eriophorum angustifolium and Carex rotundata was measured in a long-term experimental wet sedge tundra site near Toolik Lake, AK. Experimental treatments at each site included factorial NxP, greenhouse and shadehouse and were begun in 1989 (Toolik sites).
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).
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.
The Anaktuvuk River Fire occurred in 2007 on the North Slope of Alaska. In 2008, three eddy covariance towers were established at sites representing unburned tundra, moderately burned tundra, and severely burned tundra. Eriophorum vaginatum flowers were counted from annual photographs of each site during peak flowering season (6/17-7/20).
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.
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.
Data on the effects of shading tundra vegetation from the sun when it is low in on the horizon in the north. If light quality was altered through shading, phenology might be affected. Senescence (color change) was measured for the common tundra species.
Data on Eriophorum vaginatum leaf length collected from common gardens established at Toolik Lake, Coldfoot, and Sagwon in 2014 with tussocks from Coldfoot, Toolik Lake, and Sagwon. Data collected during the growing seasons of 2015, 2016, and 2017
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 on litter decomposition of Eriophorum vaginatum leaves collected at Toolik Lake, Coldfoot, and Sagwon and distributed to all three sites. Litter bags from the three populations were deployed at CF (8/26/15), TL (8/24/16) and SG (8/25/16) sites approximately 40 meter away from the main transplant gardens (east of CF, east of TL and west of SG) into 5 blocks with 4 intended harvests at each plots.
Data on Eriophorum vaginatum leaf length collected from a common garden established at Toolik Lake in 2011 with tussocks from No Name Creek, Coldfoot, Eagle Creek, Toolik Lake, Sagwon, and Prudhoe Bay. Data collected during the growing seasons of 2015 and 2016. Results published in Parker, T. C., J. Tang, M. B. Clark, M. M. Moody, and N. Fetcher. 2017. Ecotypic differences in the phenology of the tundra species Eriophorum vaginatum reflect sites of origin. Ecology and Evolution 7: 9775-9786. doi: 10.1002/ece3.3445
This was an experimental burn conducted in the summer of 2015 to provide sites for an experiment to see whether seeds of Eriophorum vaginatum from different ecotypes could establish in recently burned areas. It consisted of ten 2 meter X 2 meter plots along with a similar number of control plots. There was little seedling establishment but other data have been collected on the plots.
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.