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.
Data Set Results
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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.
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.
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.
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.
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.
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.
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.
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.
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.
Hourly weather data from the Arctic Tundra LTER wet sedge experimental site at Toolik Lake. The following parameters are measured every minute and averaged every hour: control plot air temperature and relative humidity at 3 meters and greenhouse plot air temperature and relative humidity at 1 meters (inside the greenhouse).
Soil temperature data collected every 4 hours from a wet sedge site at the Arctic Tundra LTER site at Toolik Lake. Temperatures are measured every 3 minutes and averaged every 4 hours in control, nitrogen alone, phosphorus alone, nitrogen and phosphorus, and greenhouse experimental plots soil temperatures.
Output data sets of the MBL-GEM III model for a typical tussock-tundra hill slope. The model is described in two papers:
Le Dizès, S., Kwiatkowski B.L., Rastetter E.B., Hope A., Hobbie J.E., Stow D., Daeschner S., 2003 Modelling biogeochemical responses of tundra ecosystems to temporal and spatial variations in climate in the Kuparuk River Basin (Alaska), Journal of Geophysical Research Vol. 108 No. D2 10.1029/2001JD000960.
Output data set of the MBL-GEM III model run for tussock tundra in the Kuparuk River Basin, Alaska, described in detail in Le Dizès, S., B. L. Kwiatkowski, E. B. Rastetter, A. Hope, J. E. Hobbie, D. Stow, and S. Daeschner, Modeling biogeochemical responses of tundra ecosystems to temporal and spatial variations in climate in the Kuparuk River Basin (Alaska), J. Geophys. Res., 108(D2), 8165, doi:10.1029/2001JD000960, 2003.
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.
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.
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.
The Kuparuk River has been the central research location on the impact of added phosphorus to arctic streams. Additions of phosphorus occred since 1983. Today, 4 specific reaches show certain characteristics based on the years that they recieved fertilization. Whole Stream Metabolism is a way to quantify primary production of this stream system. Calculations were done using dissolved oxygen, discharge, stage, light and temperature measured by sondes and other equipment strategically deployed in the field at locations to quantify each of the unique stream reaches.
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.
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.
Relative percent cover was measured for plant species on Arctic LTER experimental plots at Toolik field station in moist acidic and non-acidic tundra.
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.
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.
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.
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
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 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.