A spectrophotometer was used to scan the canopy vegetation of ITEX harvest plots. The resulting reflectance spectra were used to calculate several vegetation indices of interest (NDVI, EVI, EVI2, PRI, WBI, Chlorophyll Index). Average values of these vegetation indices for each ITEX harvest plot are presented here. These plots also had biomass harvests performed and were analyzed for leaf area and nitrogen content (see 2003-2009gsharvest.csv, 2003-2009gsharvestLAI-N.csv).
Data Set Results
Soil temperature, moisture content and thaw depth of the ITEX flux survey plots. Survey 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; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made 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.
Estimated aerial plant % cover by functional type in flux plots measured during the ITEX cirumarctic flux survey 2004-2006. Survey 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; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Ecosystem CO2 flux light response curves were measured on 1m x 1m plots ( some 0.3m x 0.3m plots in 2006 and some 0.7m x0.7m plots in 2009) across the arctic. This file contains the best fit parameters that describe these light response curves, together with corresponding NDVI data for each curve.
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.
Ecosystem CO2 flux light response curves were measured on 1m x 1m plots across the arctic. This file contains the CO2 and H2O flux measurements and NDVI data for each plot. Survey 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; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska. Measurements were made during the growing seasons 2003 to 2009.
Estimated aerial plant % cover by species in flux plots measured during the ITEX circumarctic flux survey 2004-2006. Flux 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; at various sites in Adventdalen, Svalbard; in the Zackenberg valley, Northeast Greenland; at BEO near Barrow, Alaska and at the Anaktuvuk River Burn in Alaska.
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. Several times during the 2008-2014 growing seasons, thaw depth was measured at approximately 70 points near each of these towers . Data presented here are the individual measurements for each site and date.
A summary of below ground root biomass, carbon and nitrogen concentrations, measured at three sites at and around the Anaktuvuk River Burn: severely burned, moderately burned and unburned.
Below ground soil bulk density, carbon and nitrogen was measured at various depth increments in mineral and organic soil layers at three sites at and around the Anaktuvuk River Burn: severely burned, moderately burned and unburned. This data corresponds with the aboveground biomass and root biomass data files: 2011ARF_AbvgroundBiomassCN, 2011ARF_RootBiomassCN_byDepth, 2011ARF_RootBiomassCN_byQuad, 2011ARF_RootBiomassCN_byQuad.
Above ground plant and below ground stem biomass were measured in 2011 from three sites at and around the Anaktuvuk River Burn: severely burned, moderately burned and unburned. These samples were analyzed for carbon and nitrogen concentrations.
Summarized below ground soil carbon and nitrogen concentrations measured in quadrats at three sites at and around the Anaktuvuk River Burn: severely burned, moderately burned and unburned. This data corresponds with the aboveground biomass and root biomass data files: 2011ARF_AbvgroundBiomassCN, 2011ARF_RootBiomassCN_byDepth, 2011ARF_RootBiomassCN_byQuad, 2011ARF_SoilCN_byDepth.
Below ground root biomass was measured by depth increments at three sites at and around the Anaktuvuk River Burn: severely burned, moderately burned and unburned. Roots were also analyzed for carbon and nitrogen concentrations.
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).
A spectrophotometer was used to scan the canopy vegetation of ITEX flux plots. The resulting reflectance spectra were used to calculate several vegetation indices of interest (NDVI, EVI, EVI2, PRI, WBI, Chlorophyll Index). Average values of these vegetation indices for each ITEX flux plot are presented here.
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.
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
This file contains leaf area index (LAI) based on biomass measurements from an aboveground pluck in the southern portion of the Anaktuvuk River fire scar, and a nearby unburned site in late July 2017. Vegetation was sampled randomly at 10-m intervals along two 100 meter transects at both the burned and unburned sites. Vegetation was sampled within a 10X40 cm quadrat to the mineral layer, and plant material was sorted into new and old aboveground leaf and woody biomass by species.
This file contains maximum plant heights from point frame measurements made in the southern section of the 2007 Anaktuvuk River fire scar, at a severely burned site and a nearby unburned site. Pin-vegetation contact was recorded using a 0.56 m2 frame with 41 evenly spaced sampling points. Data were collected during peak green in summer 2019.
Tillers from 24 Eriophorum vaginatum individuals were sampled in late July 2019 to examine differences in percent nitrogen between previously burned (Anaktuvuk River Fire) and unburned tussocks at a nearby unburned control site. At the burned site tussocks exhibiting evidence of rodent grazing were also sampled to separate herbivore effects from those of the fire. From each tussock, 3-4 new leaves were sampled (as indicated by lack of brown tips) and dried at 60°C for 24 hours, before being ground and analyzed for percent nitrogen.
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.