Relative percent cover of plant species in LTER moist acidic, dry heath, and moist non-acidic tundra experimental plots; in new experimental plots established in 2006; and for Sagavanirktok River plots in tussock and heath tundra, Norht Slope Alaska 2008.

Abstract: 

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.

Project Keywords: 

Data set ID: 

10490

EML revision ID: 

5

Short name: 

2008lgcover
People

Keywords: 

Arctic LTER keywords: 

Taxa: 

Dates

Date Range: 

Tuesday, July 15, 2008 to Monday, July 28, 2008

Publication Date: 

Sunday, December 12, 2010

Methods: 

The LTER moist acidic tussock (Toolik MAT) site was set up in 1989. The experimental design is four blocks of 5 x 20 meter plots with randomly assigned treatments within each block. Treatments include control (CT), nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (NP). Fertilizer is added annually following snowmelt in June as 10 g/m2 nitrogen (as NH4NO3) and 5 g/m2 phosphorous (as triple superphosphate). Exclosure plots were set up at the MAT site in July 1996 on extra 5 x 20 meter plots within the four-block design of the 1989 LTER acidic tussock experimental plots. On each plot a 5 x 10 meter section was fenced with large mesh (4-inch square mesh) and within this fence a 5x5-meter plot was fenced with a small mesh (1/2-inch square mesh). In each block two fenced plots were setup: a plot with no fertilizer and a plot with annual fertilization treatments as described above. Thus the treatments created are no fence, no fertilizer (NFCT); small mesh fence, no fertilizer (SFCT); large mesh fence, no fertilizer (LFCT); no fence, N plus P (NFNP); small mesh fence, N plus P (SFNP); and large mesh fence, N plus P (LFNP). Only NFCT, NFNP, SFCT, and SFNP were censused in 2004. The LTER dry heath (Toolik DH) site was also established in 1989 using the same methods at MAT in three block replicates. Exclosure plots were set up in 1996 using the same methods at MAT. In 1997 experimental plots were established at the LTER moist non-acidic tussock (Toolik MNT) site with the same methods as those used at MAT. CT, N, P and NP treatments are replicated in three blocks at MNT. The Sagavanirktok River (Sag) site was set up in 1984 and contains six vegetation types along a toposequence on the floodplain terrace. Vegetation types are moist tussock tundra, dry heath tundra, snowbed, equisetum/forb, wet sedge tundra, and riparian shrub. Each vegetation type had control (CT), nitrogen (N), phosphorus (P), and nitrogen plus phosphorus (NP) treatments. Fertilizers are added in the same way as the LTER tundra sites. Percent cover was recorded on tussock tundra and heath tundra types. Calculations: All percent cover values were summed within each plot, and then each value was divided by the total to generate a percent cover value standardized to 100%. Reference Citations: Gough, L. and S.E. Hobbie. 2003. Responses of moist non-acidic arctic tundra to altered environment: productivity, biomass, and species richness. Oikos 103:204-216. Gough, L., P.A. Wookey, and G.R. Shaver. 2002. Dry heath arctic tundra responses to long-term nutrient and light manipulation. Arctic, Antarctic, and Alpine Research. 34: 211-218. Shaver, G.R., J.A. Laundre, A.E. Giblin, and K.J. Nadelhoffer. 1996. Changes in live plant biomass, primary production and species composition along a riverside toposequence in Arctic Alaska, U.S.A. Arctic and Alpine Research. 28: 363-379. Sampling Description. Permanent monitoring areas were established in all treatment plots in 1998. Eight 1 m2 plots are sampled in each treatment in each block each year at the end of July. A 1 m2 quadrat is aligned 0.2 m inside of the plot at the site of a flag marking the first measurement. Within this quadrat, aerial percent cover of all vascular plants are noted by species as is all other ground cover. Categories include moss (all species lumped), lichen (all species lumped), litter, and standing dead Betula nana. Bare ground, frost boil, and water are also recorded. As an indicator of vole activity, the percent cover of the plot comprised of vole burrow holes, vole trails, and vole litter (small pieces of dead plant material) are also recorded. To standardize cover among plots, all percent cover values were summed within each plot, and then each value was divided by the total to generate a percent cover value standardized to 100%.

In 2006, a new set of experimental treatments were established in MAT near the earlier plots described above. These include a gradient of fertilization treatments that receive nitrate or ammonium alone, or receive N and P additions with 0.5, 1, 2, 5, or 10 g N added with half of that amount added as P. An additional set of plots were set aside upon establishment for future experiments, and are noted as H. We sampled from blocks 1-3 in 2008 from the following treatments: 06CT, 06F0.5, 06F1, 06F2, 06F5, 06F10, 06NO3, 06NH4, 06H.

Gough, L. and S.E. Hobbie. 2003. Responses of moist non-acidic arctic tundra to altered environment: productivity, biomass, and species richness. Oikos 103:204-216.

Sites sampled.

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File 2008lgcover.csv

Relative percent... File Details

Office spreadsheet icon 2008lgcover.xls

Excel file with... File Details

Variables Details

(Variables names are in the first line/row of the CSV file and Excel data sheet.)
Year
  • Label: Year
  • Definition: The year of percent cover measurement.
  • Type: Date/time
  • Date format: yyyy
  • Missing values: None specified
Site
  • Label: Site
  • Definition: The site of percent cover measurement
  • Type: Nominal
  • Missing values: None specified
Treatment
  • Label: Treatment
  • Definition: The manipulated treatment
  • Type: Nominal
  • Missing values: None specified
Block
  • Label: Block
  • Definition: The treatment block number
  • Type: Nominal
  • Missing values: None specified
Plot
  • Label: Plot
  • Definition: Sample plot where precent cover was measured
  • Type: Nominal
  • Missing values: None specified
Species
  • Label: Species
  • Definition: Species and cover categories determined on plots as described above
  • Type: Nominal
  • Missing values: None specified
Relative Cover
  • Label: Relative Cover
  • Definition: The percent cover of a given species relative to the total cover of the plot
  • Type: Physical quantity
  • Unit: percent
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values:
    • NA = missing or not measured