The type of vegetation in a region depends on its climatic conditions (Fig 1).
Fig 1. The kinds of natural vegetation that prevail in various combinations of annual total rainfall and mean temperature conditions (1). T signifies tundra, SG summer-green deciduous forest, G grassland, RG seasonally green forest, TF tropical rainforest, D (semi-) desert scrubland.
(1) Lieth, H. 1875. Modelling the primary productivity of the world. In (2), p. 233-63.
(2) Lieth, H. and R.H. Whittaker (eds) 1975. Primary Productivity of the Biosphere. (Springer-Verlag) 339pp.