Arctic Vegetation Archive - Alaska: Atqasuk.
The Atqasuk vegetation plots were originally described and mapped by Drs. Vera Komárková and Patrick J. Webber in 1975 as part of the Research on Arctic Tundra Environments (RATE) project. These sites were resampled in 2000 and 2010 and assessed for community change as part of the 'IPY Back to the Future: Resampling old research sites to assess changes in high latitude terrestrial ecosystem structure and function project' (NSF Award No. 0732885). The tundra at Atqasuk is located within the Arctic Coastal Plain and the landscape is characterized by polygons, drained lake basins, ponds, lakes, meandering streams and has the Meade River in close proximity.
Sixty sites (600 sub-plots) were originally established in 1975 and were used to characterize 9 plant communities for the Back to the Future project including: 1) Arctophila wetland (1 site), 2) Carex wetland (7 sites), 3) Sphagnum moist tundra (13 sites), 4) Carex-Salix moist tundra (15 sites), 5) Moss moist tundra (3 sites), 6) Dry ridge tundra (8 sites) and 7) Dune shrub tundra (4 sites, 8) Snowpatch tundra (2 sites), and 9) Dry Dryas tundra (7 sites).
Each vegetation site consists of a 1m x 10m belt with a 1m x 10cm strip along the inside. Each site is divided into 10 sub-plots in which species percent cover is visually estimated in the 1m x 10cm strip and species presence in the 1m x 90cm sub-plot. The vegetation plot data chosen for inclusion in the Alaska-AVA are mean summaries of the 10 1m x 1m sub-plots.
Original data from 1975 were classified and a map of the region was published along with descriptions of communities (Komárková and Webber 1980). The 1975 plot data were subsequently lost. Only Species Index Values (Species Index Value = (Relative Cover + Relative Presence)/2) for plots were recovered from punch cards. These data are not included in the Turboveg database, but are available as ancillary data. The 1975 data and the corresponding resampling data from 2000 and 2010 for the 31 relocated sites (310 sub-plots) were assessed for change and published in a dissertation (Villarreal 2013).
References
Komárková, V., and P. J. Webber. 1980. Two Low arctic vegetation maps near Atkasook, Alaska. Arctic, Antarctic, and Alpine Research 12:447–472.
Tweedie, Craig (2013): IPY Back to the Future (BTF): Re-sampling old research sites to assess change in high latitude terrestrial ecosystem structure and function. UCAR/NCAR - CISL - ACADIS. Dataset. Updated August 12, 2014. http://dx.doi.org/10.5065/D6XS5SD1
Villarreal, S. 2013. International Polar Year (IPY) Back to the Future (BTF): Changes in arctic ecosystem structure over decadal time scales. Doctoral Dissertation. The University of Texas at El Paso.
