Vegetation and environment — introductory concepts

Abstract

Plants are a general feature of the natural landscape and grow in all but the most extreme environments. However, no species occurs everywhere in the world, each being distributed according to its own unique tolerance of the multitude of factors that comprise its environment. Species with similar ecological tolerances develop into recognizable plant formations with distinctive floristic and structural characteristics. At the broadest scale these represent the major biomes of the world. The regional extent of each biome is primarily determined by climatic conditions and this is the basis of most schemes of vegetation classification. Of historical importantance is the work of de Candolle who, in 1874, proposed that the major plant formations were distributed according to the heat requirements and drought tolerance of the plants. Although this early explanation has now been superseded, the general concepts were subsequently incorporated into the widely used Köppen system of climate classification (Table 1.1).