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.
Data Set Results
Biomass of belowground community groups (bacteria, fungi, protozoa, nematodes, rotifers, tardigrades) determined for organic and mineral soils in moist acidic tundra. Soil carbon and nitrogen content, bulk density, and depth are included.
Biomass of belowground community groups (bacteria, fungi, protozoa, nematodes, rotifers, tardigrades) determined for organic and mineral soils in moist acidic tundra.
Soil samples were collected from control, and N+P plots from within a set of treatments in Arctic LTER Moist Acidic Tundra plots established in 1989 and in 2006 . At the time of sampling the soil was separated into organic horizon, organic/mineral interface, and the upper 5cm of the mineral soil. In the lab the potential activities of seven hydrolytic enzymes was determined using fluorometric techniques (Saiya-Cork et al. 2002) modified following Steinweg et al(.2012).
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.
In arctic tundra near Toolik Lake, Alaska, we incubated a common substrate in a snow addition experiment to test whether snow accumulation around arctic deciduous shrubs altered the environment enough to increase litter decomposition rates. We compared the influence of litter quality on the rate of litter and N loss by decomposing litter from four different plant functional types in a common site. We used aboveground net primary production values and estimated k values from our decomposition experiments to calculate community-weighted mass loss for each site.
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.
Percent moisture, bulk density, percent loss on ignition and percent organic carbon were measured for peat collected from soils in the Imnavait Creek watershed.
The data set describes soil ergosterol concentration, which is unique to fungal membranes., from samples from Abisko, Sweden. The samples from Abisko, Sweden, were collected by E.A. Hobbie at a birch forest site and a tundra site. The Abisko sites are described in www.abacus-ipy.org/fieldsites/abisko.html.
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.
del 13C and del 15N ratios were measured for plant and lichen in watertracks in the Toolik Lake drainage and the east facing slope of the Imnavait Creek area. Sampling locations for each species for a specific date were chosen across an elevation gradient starting from the lakeside and leading to ridge crest. The vegetation was dried and analyzed for stable isotopes.
In situ soil respiration measured in the Arctic LTER treatment plots in moist acidic tussock and moist non-acidic tussock 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.
Total soil cations (Al, Ca, K, Mg, Na, P) for intertussock O and B horizon soils on moist acidic and non-acidic tundra.
Soil aggregate size distribution, aggregate carbon and nitrogen, and light fraction carbon were determined for mineral soils in moist acidic tundra. Soil was sampled in control, and N+P plots of the Arctic LTER Moist Acidic Tundra plots established in 1989 and 2006.
Foliar nutrients (N, P, K, Ca, Mg, Al) for dominant species on moist acidic and non-acidic tundra, Arctic LTER, Toolik Field Station , Alaska, 1999.
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.
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.
Vascular plant species list, Skip Walker's Toolik Lake permanent plot species data
Biomass of belowground community groups (bacteria, fungi, protozoa, nematodes, rotifers, tardigrades) determined for organic and mineral soils in moist acidic tundra sampled in the moist acidic tundra nutient (N&P) addition and greenhouse plots in July 2008.
Biomass of soil rotifers, tardigrades, enchytraeids, protozoa and nematode groups from organic and mineral soils in moist acidic tundra nutrient addition plots (since 2006) sampled August 2012.
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.
Biomass of belowground community groups (bacteria, fungi, protozoa, nematodes, rotifers, tardigrades) determined for organic soils in moist acidic tundra and dry heath tundra.
Organic and mineral soil cores were collected from 18 transects differentiated by shrub height into three replica groups: high (average 64 cm ± SE 1.01); medium (39 ± SE 1); and low (18 ± SE 0.4); and percent plant functional group cover. Replica sample cores were taken from each transect, and after homogenization and K2SO4 extraction, if required, samples were analyzed for % C (carbon) and N (nitrogen); non-purgeable organic C (NPOC); total N (TN); dissolved inorganic and organic N (DIN, DON); microbial biomass C (MB-C) and N (MB-N).
Foliar and litter nutrients and retranslocation efficiencies (N, P, K, Ca, Mg) for dominant species on moist acidic and non-acidic tundra, Arctic LTER, Toolik Field Station , Alaska, 1999.
Del 13C was determined on dissolved organic carbon from Imnavait Creek water collected from the fourth pond upstream of the Imnavait Creek flume in 1990 and 1991. Radiocarbon was determined on a sample in each year.
The data set describes soil ergosterol concentration, which is unique to fungal membranes., from an Alaska transect . The soil samples from Alaska were collected in a trip from north to south along the Dalton Highway. north of the Yukon River.
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.
del 13C and del 15N ratios were measured on a peat core at 2 cm depth intervals. Peat cores were taken at Imnavait Creek, Pump Station 3, the Happy Valley Steram and Olikok Dock Road along the Dalton Highway, Alaska.
The original focus of this study was an analysis of proteolytic enzyme activity of Alaskan arctic tundra soils, however initial results raised questions regarding the method (Watanabe and Hayano, 1995). Thus, the goals of the study changed to 1) an investigation of the method, and 2) a comparison of enzyme activities of two different soil layers from the arctic tundra.
Extractable soil cations (K, Ca, Mg, Na) for intertussock O and B horizon soils on moist acidic and non-acidic tundra.
In arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance and height of deciduous shrubs.
These data are from two remote field campaigns in the Noatak National Preserve. Various thermokarst features and their receiving streams were sampled and characterized. A suite of water chemistry (nutrients, major anions and cations, total suspended sediment) and benthic variables (particulate carbon, nitrogen and phosphorus, and chlorophyll-a) were measured at 6 major sites (2 in 2010 and 4 in 2011). There were additional sites sampled for water chemistry above and below thermokarst features in 2011.
File contains temperature and discharge data for Lake NE 14 Outlet during the 2011 summer field season.
Water samples were taken at 5 locations at both I-Minus2 and Toolik River thermokarst sites (10 sampling locations total). A combination of ISCO and manual grab samples were taken depending on the sampling location and year.
Using a combination of aerial imagery and ~1m resolution airborne lidar (collected July, 2009), we use manual visual inspection of the two datasets to identify point locations of over 7000 thermal erosion features (thermokarst) of varying maturity. For each feature we report its x,y position, the facing direction of the feature, the local topographic setting, the geologic unit it occurs on, the relative age of the feature and the specific type of thermal erosion feature.
Data were collected to investigate if formation of gully thermokarst (TK) results in lowering of the water table and more rapid evacuation of water from above the frost table. Data were collected from 24 shallow screened wells. 2 replicate rows of 4 wells were located at: (a) a hillslope (HS) ~120m away from the gully TK, (b) perpendicular to the gully TK (TK) and (c) perpendicular to an unimpacted water track (WT) upstream of the gully TK. Note that water levels are the distance below the ground surface and may have organic/peat layers of different thicknesses.
File contains temperature and discharge data for Lake NE 14 Outlet during the 2010 summer field season.
File contains temperature and discharge data for lake NE 14 Outlet during the 2009 summer field season.
Surface organic and mineral soil layers were sampled in retrogressive thaw slump disturbance scars and nearby undisturbed tundra to estmate the influence of this thermo-erosional--thermokarst--disturbance type on soil carbon (C) and nitrogen (N) pools. Within six independent sites, we identified multiple thaw slump scars and determined time after disturbance for each scar by (1) aging the population of tall deciduous shrubs rooted in the mineral soil and (2) by dating the basal layer of the re-accumulating soil organic matter.
The (ARCSSTK) did extensive research during 2009-2011 field seasons in Arctic Alaska. The objective of this data set was to measure the quantity and biodegradability of DOC from headwater streams and rivers across three geographic regions and across four natural ‘treatments’ (reference; thermokarst-; burned-, and thermokarst + burned-impacted streams) to evaluate which factors most strongly influence DOC quantity and biodegradablity at a watershed scale.
This file contains data collected from thermokarst impacted soils, lakes, and streams near Toolik Lake Alaska. Data are also presented for experimental manipulations of water (e.g., time course experiments). Sample descriptors include a unique sortchem #, site, date, time, depth, distance, elevation, treatment, date-time, category, and water type (e.g., lake, surface, soil). Physical/chemical measures collected in the field include temperature, conductivity, and pH.
The (ARCSSTK) did extensive research during 2009-2011 field seasons in Arctic Alaska. The objective of this data set was to measure the quantity and biodegradability of DOC from headwater streams and rivers across three geographic regions and across four natural ‘treatments’ (reference; thermokarst-; burned-, and thermokarst + burned-impacted streams) to evaluate which factors most strongly influence DOC quantity and biodegradablity at a watershed scale. This table provides physical site characteristics for the locations sampled for stream water biodegradability.
GroMeteorological parameters were measured hourly adjacent to thermokarst features in the region around Toolik Field Station. Pressure, rainfall, wind speed and direction, solar radiation, air temperature and relative humidity were all measured at 1-3m above the ground surface with an Onset U30 weather station connected to all sensors.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. NE14_TS02dot02_temp is located in the old NE14 thermokarst, upslope.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. TRTK_GT01dot05_temp is located outside the TRTK thermokarst, midslope.
Ground temperatures were measured hourly at ~20-50cm intervals below the ground surface inside and adjacent to thermokarst features in the region around Toolik Field Station. Ground temperatures were measured using Hobo thermistors. Temperatures at 0 and 20cm depths were measured directly in the ground whereas 40cm and deeper measurements were logged from dry wells installed in summer 2009. IM2_GT01dot06_temp is located inside of the I-Minus-2 Gulley thermokarst, downslope.
Hourly air temperature, humidity, wind speed, soil temperature and soil water data from the control area of the ITEX tussock tundra snowfence study site