1. Barbour, M.G. (1973) Desert dogma reexamined: Root/shoot productivity and plant spacing. American Midland Naturalist
89, 41 – 57.
2. Billings, W.D. (1949) The shadscale vegetation zone of Nevada and eastern California in relation to climate and soils. American Midland Naturalist, 42, 87 – 109.
3. Björkman, O. (1975) Environmental and biological control of photosynthesis, in: Environmental and Biological Control of Photosynthesis(ed. by R. Marcelle ), Junk, The Hague, pp. 1 – 16.
4. Boutton, T.W., Harrison, A.T. and Smith, B.N. (1980) Distribution of biomass of species differing in photosyn-thetic pathway along the altitudinal transect in southeastern Wyoming grassland. Oecologia, 45, 287 – 98.
5. Breckle, S.W. (1975) Zur Ökologie and zu den Mineralstoff verhältnissen absalzender and nichtabsalzender Xerohalophyten, Habilitationsschrift, Universität Bonn, 169 pp.