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The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, educational, government, recreational, or other not-for-profit professional purposes. The Data User is permitted to produce and distribute derived works from this dataset provided that they are released under the same license terms as those accompanying this Data Set. Any other uses for the Data Set or its derived products will require explicit permission from the dataset owner.
2 ) Redistribution. The data are provided for use by the Data User. The metadata and this license must accompany all copies made and be available to all users of this Data Set. The Data User will not redistribute the original Data Set beyond this collaboration sphere.
3 ) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly cite the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier. For example:

Shaver, G. 1989. Above ground biomass in acidic tussock tundra experimental site, 1989, Arctic LTER, Toolik, Alaska. Arctic LTER, Marine Biological Lab, Woods Hole, Ma 02543. 1989gsttbm 

4 ) Acknowledgement. The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed significantly to its content. Acknowledgements should identify the supporting party, the party that received the support, and any identifying information such as grant numbers. For example:

Data sets were provided by the Arctic LTER. This material is based upon work supported by the National Science Foundation under Grants #DEB-981022, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493.

5 ) Notification. The Data User will notify the Data Set Contact when any derivative work or publication based on or derived from the Data Set is distributed. The Data User will provide the data contact with two reprints of any publications resulting from use of the Data Set and will provide copies, or on-line access to, any derived digital products. Notification will include an explanation of how the Data Set was used to produce the derived work.
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While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

Dataset URLs:METADATA: HTML, Rich Text, XML(EML compliant)
DATA: Comma Delimited, Excel file with Metadata and data, Dataset via LTER Data Poral
Dataset ID:2012lgcover.02
Dataset Title:2012 relative percent cover of plant species in LTER moist acidic tundra experimental plots and in new experimental plots established in 2006.
Investigator 1: 
First Name:Laura
Last Name:Gough
Organization:Department of Biology
Address line 2:Box 19498
Address line 3:University of Texas at Arlington
Zip Code:76019
Investigator 2: 
First Name:Jennie
Last Name:McLaren
Address line 2:
Address line 3:
Zip Code:
Investigator 3: 
First Name:Ashley
Last Name:Asmus
Associate Investigators:
Keywords:plant cover, Alaska, diversity, tundra, relative abundance, disturbance, populations, moist acidic tundra, Toolik
Abstract:In 2012, relative percent cover of plant species was measured in LTER moist acidic tundra experimental plots and in new experimental plots established in 2006.
For questions about the Metadata and data contact the Investigators.
For information about this web site contact:
Arctic LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7496
Online URL:
Data File URL
Data File Name 2012lgcover
Beginning Date 7/13/2012
End Date 7/16/2012
Number of Data Records 3225
Other Files to Reference
Availability Status
Quality Control Information
Maintenance Description
Log of Changes: Version 1: Data entered by AA and LG, validated and uploaded Dec.2013 (JD)
Version 2: Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 17Feb14
Location Name LTER Moist Acidic Tussock Tundra LTER Low Nutrient Moist Acidic Tussock Tundra Select Site or enter New One  
Geographic Description Arctic LTER Experimental Plots: Moist Acidic Tussock Tundra (MAT) Northeast corner block 1 near Toolik Field Station, North Slope, Alaska. Low Nutrient Moist Acidic Tussock Tundra (LMAT) Northeast corner Block 1 Enter Description  
Location Bounding Box        
West Bounding Coordinate        
East Bounding Coordinate        
North Bounding Coordinate        
South Bounding Coordinate        
OR if single point location        
Latitude 68.624411 68.622865 In Decimal Degrees  
Longitude -149.609589 -149.608545 In Decimal Degrees  
Elevation 750 758 In Meters  
Link to Google Map View on Google Map View on Google Map    
Organisms studied Andromeda polifolia; Arctagrostis latifolia; Arctostaphylos alpina; Astragalus umbellatus; Calamagrostis lapponica; Calamagrostis canadensis; Carex aquatilis; Carex bigelowii; Carex microchaeta; Cassiope tetragona; Diapensia lapponica; Dryas integrifolia; Dryas octopetala; Empetrum nigrum; Equisetum arvense; Eriophorum angustifolium; Eriophorum vaginatum; Hierochloe alpina; Ledum palustre; Loiseleuria procumbens; Minuartia arctica; Pedicularis; Poa pratensis; Polygonum bistorta; Polygonum viviparum; Pyrola grandiflora; Rhododendron lapponicum; Rubus chamaemorus; Salix arctica; Salix glauca; Salix phlebophylla; Salix pulchra; Salix reticulata; Saussurea angustifolia; Saxifraga; Stellaria longipes; Tofieldia coccinea; Trisetum spicatum; Vaccinium uliginosum; Vaccinium vitis-idaea; Montia bostockii; Chamerion latifolium; Orthilia secunda
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.

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.

Data Table

Variable Name Variable Description Data Type Units DateTime Format Code Information Missing Value Code
Year The year of percent cover measurement. datetime   yyyy    
Site The site of percent cover measurement text        
Treatment The manipulated treatment text        
Block The treatment block number text        
Plot Sample plot where precent cover was measured text        
Species Species and cover categories determined on plots as described above text        
Relative Cover The percent cover of a given species relative to the total cover of the plot number percent      

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