1. Arft AM, Walker MD, Gurevitch J, Alatalo JM, Bret-Harte MS, Dale M, Diemer M, Gugerli F, Henry GHR, Jones MH, Hollister RD, Jonsdottir IS, Laine K, Levesque E, Marion GM, Molau U, Molgaard P, Nordenhall U, Raszhivin V, Robinson CH, Starr G, Stenstrom A, Stenstrom M, Totland O, Turner PL, Walker LJ, Webber PJ, Welker JM, Wookey PA (1999) Responses of tundra plants to experimental warming: Meta-analysis of the International Tundra Experiment. Ecol Monogr 69:491–511
2. Alexander V, Schell DM (1973) Seasonal and spatial variation of nitrogen fixation in the Barrow, Alaska, Tundra. Arct Alp Res 5:77–88
3. Alexander V (1974) A synthesies of the IBP tundra biome circumpolar study of nitrogen fixation. In: Holding AJ, Heal OW, MacLean SF, Flanagan PW (eds) Soil Organisms and Decomposition in Tundra. Biome Steering Committee, Stockholm, pp 109–121
4. Alexander VM, Billington M, Schell DM (1978) Nitrogen fixation in arctic and alpine tundra. In: Tieszen LL (ed) Vegetation and Production Ecology of an Alaskan Arctic Tundra. Springer, New York, pp 539–558
5. Anderson DC, Harper KT, Holmgren RC (1982) Factors influencing development of cryptogamic soil crusts in Utah deserts. J Range Manag 35:180–185