NPP Tundra: Toolik Lake, Alaska, 1982

Data Citation

Cite this data set as follows:

Shaver, G. R. 2001. NPP Tundra: Toolik Lake, Alaska, 1982. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.

Description

Productivity of four contrasting vegetation types was studied during 1982 near Toolik Lake, Alaska, U.S.A. Above-ground biomass and below-ground stem/ rhizome biomass were measured on three occasions during the growing season; for (1) a "tussock" tundra containing graminoids, deciduous shrubs and evergreen shrubs, (2) a "shrub" tundra dominated by deciduous willow shrubs, (3) a "heath" tundra of evergreen shrubs, and (4) a "wet" tundra site containing rhizomatous graminoids. Vegetation was sampled using randomly located quadrats from 20 cm x 20 cm to 50 cm x 50 cm in size. The study sites were selected to represent extreme examples of the wide range of local plant growth forms.

The study areas were mostly located close to Toolik Lake, in the northern foothills of the Brooks Range on the North Slope of Alaska (68.63 N 149.72 W). The wet tundra site was about 15 km further to the south (68.45 N 149.37 W). By road, the Toolik Lake research station is 210 km south of Prudhoe Bay airport, and 570 km north of the city of Fairbanks. Tussock tundra is the dominant vegetation form in the region, but there are extensive areas of wet sedge tundra, drier heath tundra on ridge tops and other well-drained sites, and riparian willow communities.

Climate is typical of arctic regions, with a mean annual air temperature of about -7 C and low precipitation (200-400 mm; half falling as snow). The snow-free growing season extends from late May to mid-September, but freezing temperatures are possible at any time. The entire region is underlain by continuous permafrost which exerts a major influence on the distribution, structure, and function of ecosystems.

Field work at Toolik Lake is continuing on a variety of habitat types under the Arctic Long-Term Ecological Research (LTER) project, which has further detailed data available on its Web site. Studies include re-sampling of plots harvested in 1982, as well as nitrogen and phosphorus fertilisation experiments and carbon flux measurements. The Toolik Field Station is administered by the Institute of Arctic Biology, University of Alaska, Fairbanks.

Net primary productivity (NPP), excluding fine roots, was estimated at 32, 69, 158 and 305 g/m2/year, at the heath, wet, tussock and shrub sites, respectively. Leaf area index was similarly ranked. Inclusion of estimated production by roots and non-vascular plants increased these NPP figures to 140, 200, 430 and 780 g/m2/year, respectively.

Contact Information

Contact: Dr. G. R. Shaver
The Ecosystems Center
Marine Biological Laboratory
Woods Hole, MA 02543
U.S.A.

Telephone +1 (508) 548-3705
Fax +1 (508) 457-1548
E-mail: gshaver@mbl.edu

Click on the following linked phrase to view references and summaries for the Toolik sites.