Vegetation-types Map of Tanganyika

Abstract

THE Geographical Review has published a reprint of an article from the January 1949 issue entitled "A Vegetation-types Map of Tanganyika", by the late Clemert Gillman. This study of the natural vegetation of Tanganyika Territory by a man who had proround knowledge of the country and of its peque is one that should be used as a basis for wise planning, and development. The classification is strictly physiognomic and provides an essential basis for further ecological and geographical investigations. The vegetation of the greater part of Tanganyika Territory is a mixture of woodland or bushland with grassland, the distribution being primarily determined by variations of soil and water conditions and the use made of them by man, although, as the author points out, topography and tectonics influence the climate and distribution of vegetation. The main types shown on the coloured map on a scale of 1: 2,000,000 include forest, woodland, bushland and thicket, grassland, permanent swamp vegetation, desert and semi-desert, and vegetation actively induced by man in native and non-native cultivations. The term "actively induced vegetation" includes the mixed and constantly changing pattern of cultivated crops, pastures and interspersed remnants of the original vegetation and of scattered small areas of secondary growth. Complexes of vegetation occurring in close conjunction are shown on the map symbolically, using the colour of the dominating type for the ground colour with intrazonals or complexes shown by circles or dots in the colour of their type. Sequences of vegetation types caused by regularly repeated physiographic or hydrographic conditions are shown as "catenas"—a word originally applied to soils in East Africa. The map brings out at a glance the small remnants of evergreen forest left on the main watersheds, and the author stresses the urgency of the threat to the country's water resources. The map also rectifies a commonly held exaggerated view of the size of alien plantations and farming settlements, which appear as tiny specks compared with the great extent of native-cultivated land.