The nature of grassland

Robert Thomas Coupland

The term ‘grassland’ is used in this volume to refer to ecosystems in which the dominant vegetative component is comprised of herbaceous species. The other three terrestrial sections of IBP also include herbaceous floristic elements. Deserts abound in annual grasses and forbs, but only for short periods when moisture conditions permit; the permanent vegetation is of shrubs and succulents. Herbaceous species are important occupants of the ground layer of woodlands, but trees characterise and dominate the vegetation of these landscapes. The vegetation of tundra ecosystems is characterised by small shrubs, herbs, mosses and lichens, each of which is the principal contributor of organic production in different situations. Herbaceous communities in the tundra can be considered as grasslands, and interest in such areas overlaps with that of the IBP Tundra Working Group. Some of the meadows discussed in Part III are in some respects similar to certain herbaceous communities of the tundra zone, both being influenced by high moisture content in the substratum. The absence of trees in tundra and natural temperate grassland is due to low temperatures in the former and to moisture deficiency in the latter. However, in the IBP organisation, studies of heathlands and peatlands of the temperate zone were associated with those of the arctic tundra, taking with them some studies of meadows. Similarly, the interests of the Woodland and Grassland Working Groups overlap in savanna, which is characteristic of vast areas of the tropics and subtropics. These other three biomes [tundra, woodlands and aridlands] will be treated in other volumes in this series [...].

Fonte: Coupland, R. T. 1979. In: Coupland, R. T., eds. Grassland ecosystems of the world. Cambridge, CUP.