Table 1.

Ecological settings for Toolik and Zackenberg research sites

	Toolik field station	Zackenberg
Location	Inland, Northern Alaska 68o38′N, 149o43′W, 719 m altitude	Coast, Northeast Greenland 74o30′N, 21o30′W, 0 m altitude
Physical setting	Rolling foothills, Continuous permafrost (200 m), annual temperature −8 °C, summer (mid-June to mid-August) 9 °C, annual precipitation 312 mm	Mountain valley, Continuous permafrost (estimated 200–400 m), annual temperature −8 °C, summer (3 months) 4.5 °C, annual precipitation 261 mm
Ecology	Tussock tundra (sedges, evergreen and deciduous shrubs, forbs, mosses, and lichens). Low shrubs, birches, and willows grow between tussocks and along water tracks and stream banks. Low Arctic	Central valley floor dominated by Ericaceous evergreen (Cassiope tetragona), by heaths and arctic willow (Salix arctica)j, and by snow-beds, grasslands, and fens. This High Arctic ecosystem has relatively low biodiversity and low species redundancy
Projects	LTER (Long Term Ecological Research), ITEX (International Tundra Experiment), NOAA’s Arctic Program, CALM (Circumpolar Active Layer Monitoring), and the TFS environmental monitoring program	BioBasis programme of NERI, Danish Environmental Protection Agency, CALM (Circumpolar Active Layer Monitoring), ECOGLOBE (Aarhus University), INTERACT, World Wildlife Fund, GeoBasis, NARP