A multi-year DAILY weather file for the Arctic Tundra Long-Term Ecological Research (LTER) site at Toolik Lake, AK. Included are daily averages and/or maximums and minimums of air, wind speed, soil temperature, and sum of global radiation and precipitation.
In 2008 Toolik Field Station took over maintenance of the main weather station. See http://toolik.alaska.edu/edc/index.php for current weather data. In addition to the main weather station the Arctic LTER maintains several stations that collect data on the experimental plots.
Data Set Results
Oksrukuyik Creek stage height and calculated discharge for the summer of 1989 to present. Stream temperature and discharge measured each summer for several streams in the Toolik area. Stream height is converted into stream discharge based on a rating curve calculated from manual discharge measurements throughout the season. The principal investigator in charge of the temperature and discharge measurements is Dr. Breck Bowden.
Note: This file combines the previous individual yearly files.
The Multiple Element Limitation (MEL) model is used to simulate the recovery of Alaskan arctic tussock tundra to thermal erosion features (TEFs) caused by permafrost thaw and mass wasting. TEFs could be significant to regional carbon (C) and nutrient budgets because permafrost soils contain large stocks of soil organic matter (SOM) and TEFs are expected to become more frequent as climate warms. These simulations deal only with recovery following TEF stabilization and do not address initial losses of C and nutrients during TEF formation.
We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the first post fire growing season's energy and mass exchange at the severe burn site.
We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the 2012 post fire energy and mass exchange at the severe burn site.
The Anaktuvuk River Fire occurred in 2007 on the North Slope of Alaska. In 2008, three eddy covariance towers were established at sites represent ing unburned tundra, moderately burned tundra, and severely burned tundra. During the 2008-2014 growing seasons, canopy vegetation within the footprint of each of these towers was scanned with a handheld spectrophotometer several times throughout the growing season. Average reflectance spectra per site and collection day are presented here.
We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the 2010 post fire energy and mass exchange at the severe burn site.
We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the first post fire growing season's energy and mass exchange at the unburned site.
A rock-scrubbing technique was used to collect bottom samples at several different stations with three replicates at each station in the Kuparuk River. The stations are measured relative to the 1984 phosphorus dripper. Only July sampling dates are included in this file (ACG). The samples were preserved in ethanol then picked, sorted, counted, and measured in Duluth using a NIKON MICRO-PLAN II digitizing pad.
A Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates at several different stations. Two replicates were taken from each station. The same sampling procedure was used for all dates. The stations were measured relative to the site of the dripper ("-" = upstream of the dripper). Samples were preserved in 4% formaldehyde and transported to Orono, Maine, where invertebrates were removed by hand under 15X magnification and then identified and counted. All values are converted to individuals per square meter.
A Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates on a single date at each site. Five replicates were taken from at least two riffles at each site. Samples were preserved in 4% formaldehyde and transported to Orono, Maine, where invertebrates were removed by hand under 15X magnification and then identified and counted. All values are the mean of five replicates and have been converted to individuals per square meter.
A study investigating the mechanisms that control long-term response of tussock tundra to fire and to increases in air temperature, CO2, nitrogen deposition and phosphorus weathering. The MBL MEL was used to simulate the recovery of three types of tussock tundra, unburned, moderately burned, and severely burned in response to changes in climate and nutrient additions. The simulations indicate that the recovery of nutrients lost during wildfire is difficult under a warming climate because warming increases nutrient cycles and subsequently leaching within the ecosystem.
An experimental burn conducted in the summer of 2015 to provide sites for an experiment 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 were collected on the plots. Ion exchange membranes were used to measure nutrient availability over two time periods: Early season (June) and mid season (July).
Organic soil from either the Anaktuvik severe burn or Toolik Lake were collected to test of effect of removal of mycorrhizae on decompositon of tundra at Toolik Lake and the Anaktuvuk Burn IN 2016.
A licor 6400 with 6400-09 soil respiration chamber was used to measure soil respiration (efflux) from the cores on a weekly basis.
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
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.
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.
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.
This file contains plant-available
This file contains plant-available
Eriophorum vaginatum flower counts from annual photographs at the severe, moderate, and unburned Anaktuvuk River, Alaska, USA flux tower sites during
This file contains leaf area index (LAI) measurements from an nitrogen (N), phosphorus (P)
This file contains point-frame measurements from a
Files used to generate the data for figures in:
Rastetter, EB, Kling, GW, Shaver, GR, Crump, BC, Gough, L. Ecosystem Recovery from Disturbance Is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance between Vegetation and Soil-Microbial Processes. Ecosystems (2020). https://doi.org/10.1007/s10021-020-00542-3.
We deployed three eddy covariance towers along a burn severity gradient (i.e.
We deployed three eddy covariance towers along a burn severity gradient (i.e.
We deployed three eddy covariance towers along a burn severity gradient (i.e.
Vegetation (species) abundances were measured from LTER heath tundra herbivore exclosures using the point frame method. This file contains the number of pin hits per species for each subplot.
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation.
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation.
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.
Above ground plant biomass and leaf area were measured in a tussock tundra experimental site. The plots were set up in 1981 and have been harvested in previous years (See Shaver and Chapin Ecological Monographs, 61(1), 1991 pp.1-31.) This file contains the biomass numbers for each harvested quadrat and per cent carbon and nitrogen and phosphorous summaries for control and fertilized plots.
Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates at on the Kuparuk River in Reference (2001-2012) and Fertilized Reach (2002-2016) reach.
We used a fully factorial experiment to test effects of food availability and temperature (7.6, 12.7 and 17.4 degrees C; 50 days) on growth, consumption, respiration, and excretion of slimy sculpin (Cottus cognatus).
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.
Soil temperatures at 2 depths, 5 and 10 cm, canopy temperatures and soil moisture at 10 cm were measured in a heath tundra Arctic Long Term Experimental Research (ARC-LTER) site at Toolik Lake Field Station, North slope, Alaska. Air temperature and relative humidity and global radiation were also measured but are presented in another dataset. Only control and nutrient addition (nitrogen plus phosphorus ) treatments plots were measured .
This dataset consists of Eriophorum vaginatum tussock height and width (diameter) measurements, and was used to evaluate differences in physical strucutre of previously burned tundra (2007 Anaktuvuk River fire) and nearby unburned tundra. At each site, all tussocks that intersected four 100 meter transects were measured from soil surface to tussock top in four cardinal directions, and diameter was measured in two directions.
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.
This file contains Eriophorum vaginatum rhizome biomass from a 2017 biomass pluck of previously burned tundra (2007 Anaktuvuk River Fire) and nearby unburned tundra. Rhizome biomass from the pluck was combined with rhizome percent nitrogen estimates (2.47% at the Anaktuvuk River Fire, and 1.05% at the nearby unburned site) to estimate grams of nitrogen per meter squared, to evaluate differences in winter forage quality for the rodent herbivore, Microtus oeconomus. Percent nitrogen estimates were derived from pooled rhizome samples collected from the two sites in late 2018.
Climate change is increasing extreme weather events, but effects on high-frequency weather variability and the resultant impacts on ecosystem function are poorly understood. We assessed ecosystem responses of arctic tundra to changes in day-to-day weather variability using a biogeochemical model and stochastic simulations of daily temperature, precipitation, and light. Changes in weather variability altered ecosystem carbon, nitrogen, and phosphorus stocks and cycling rates.
Weather measurements from the Toolk Main weather station, 1989-2019. This data was originally downloaded from the Toolik Field Station Environmental Data Center March 8, 2021.
This climate record was used in Rastetter et al., Science, submitted.
The latest climate data is available at http://toolik.alaska.edu/edc/abiotic_monitoring/data_query.php