Arctic Vegetation Archive - Alaska: ATLAS-2.
The ATLAS-2 dataset is part of larger NSF-funded Arctic Transition in Land-Atmosphere System (ATLAS) project. ATLAS-2 contains the Seward Peninsula portion of the project with 52 plots at Council and Quartz Creek. The full ATLAS Transect also includes 15 releves at locations on the North Slope at Barrow, Atkasuk, Oumalik, and Ivotuk which are in the ATLAS-1 dataset (Edwards et al. 2000). The focus of the ATLAS project was to improve understanding of controls over spatial and temporal variability of terrestrial processes in the Arctic that have potential consequences for the climate system, i.e., processes that affect the exchange of water and energy with atmosphere, the exchange of radiatively active gases with the atmosphere, and delivery of freshwater to the Arctic Ocean. The purpose of the ATLAS vegetation studies were: 1) to characterize the major zonal vegetation types found along the North Slope climate gradient, 2) to quantify differences between acidic and non-acidic tundra along the same gradient, and 3) to investigate relationships between plant biomass, Leaf Area Index (LAI), and Normalized Difference Vegetation Index (NDVI). The data reported here are from a National Science Foundation funded, ATLAS study by D. A. Walker and colleagues titled ‘Arctic Climate Change, Substrate and Vegetation’ (OPP-9908829). The data from fieldwork completed in 2000 are compiled in a data report by Raynolds et al. (2002).
Reconnaissance fieldwork was conducted in 1998, while plot data (species and environmental) were collected in 2000. Similar to ATLAS-1 100 x 100 m grids were established an the plots were located within the grid. Although the plots were not permanently marked, there are latitude and longitude coordinates for all but one site. In the report there are 53 plots, however one plot (CC-C) had environmental data, but no species data and it was dropped from the Alaska-AVA dataset. The source species and environmental data for the plots were obtained from homogenous areas of dominant vegetation within the grids. In some cases where the vegetation was more heterogeneous, as for example in patterned ground, areas with frost boils, stone stripes, or closely spaced water tracks, samples were divided into representative microhabitats with each releve representing a microsite within the grid. These microsites were labeled with the letters A, B, C as needed.
Forty-five plots were assigned to 5 different arctic community types: a) tall forb and shrub vegetation on mesic-moist soil (13 plots); b) dwarf-shrub heath and low shrub vegetation on acidic poor substrate (13 plots); c) bog vegetation, acidic mires, including tussock tundra (8) plots); d) dry and mesic dwarf-shrub heath and graminoid vegetation on non-acidic tundra (9 plots); and e) lichen communities on silicate rocks (2 plots). Of the remaining 7 plots, 6 are undefined forest types (C1, C4-A, C-9, C-A, C-C, C-E) and plot C-F is not included due to insufficient community data.
The report (Raynolds et al. 2002) includes select soil descriptions, soil physical and chemical data, select LAI data, subjective site assessments, and active layer depths. In addition the report includes a preliminary Landsat MSS-derived map of the Seward Peninsula, and a report on the comparison of forest composition and structure of old and new growth Picea glauca forests.
Additional information on the ATLAS vegetation studies may be found at: http://www.geobotany.uaf.edu/atlas/atlas_sites.html
These data were subsequently used in several reports and publications listed below.
References
Ahn, J. Y. 2014. Monitoring Regional Vegetation Changes in Seward Peninsula, Alaska, using Remote Sensing Technique. Masters Thesis. Department of Geomatics Engineering, University of Calgary, Calgary, Alberta, Canada.
Raynolds, M. K., Martin, C. R., Walker, D. A., Moody, A., Wirth, D., and C. Thayer-Snyder. 2002. Atlas Vegetation Studies: Seward Peninsula, Alaska, 2000, vegetation, soil, and site information, with Seward vegetation map. Alaska Geobotany Center, Institute of Arctic Biology, University of Alaska, Fairbanks. 125 pp.
Thayer-Snyder, C. R., H. A. Maier, and D. A. Walker. 2003. A preliminary Landsat-derived land-cover map of the Seward Peninsula, Alaska: classification methods and comparison with existing data sets. ATLAS The Arctic Transitions in the Land-Atmosphere System (ATLAS) project: Seward Peninsula Sites. http://www.eol.ucar.edu/projects/atlas/. Accessed 12 May 2015.
Walker, D. A., G. J. Jia, H. E. Epstein, M. K. Raynolds, F. S. Chapin III, C. Copass, L. D. Hinzman, J. A. Knudson, H. A. Maier, G. J. Michaelson, F. Nelson, C. L. Ping, V. E. Romanovsky and N. Shiklomanov. 2003. Vegetation-soil-thaw-depth relationships along a low-arctic bioclimate gradient, Alaska: synthesis of information from the ATLAS studies. Permafrost and Periglacial Processes. 14:103-123.
