AFRICA, THE DEVASTATED CONTINENT?

Transcription

1 AFRICA, THE DEVASTATED CONTINENT?

2 MONOGRAPHIAE BIOLOGICAE Editor J. ILLIES Schlitz VOLUME 26 DR. W.JUNK b.v. PUBLISHERS THE HAGUE 1975

3 AFRICA, THE DEVASTATED CONTINENT? Man's impact on the ecology of Africa by ANTOON DE Vos DR. W.]UNK b.v. PUBLISHERS THE HAGUE 1975

4 To VANESSA without whose help this book would never have come to fruition. ISBN-13: I DOl: 10.\007/ e-isbn-13: i by Dr. W.Junk b.v., Publishers, The Hague Softcover reprint of the hardcover 1st edition 1975 Cover Design M. Velthuijs, The Hague

5 CONTENTS Foreword.... Introduction I The African environment. II Ecological zones of Africa. III Man as an environmental agent IV Specific environmental problems. V Problems, needs and potentials in land use. VI Planning for the future. Literature cited. Index

6 CHAPTER'S CONTENTS I. The African environment. 15 Geology. 15 Geography. 15 Phytogeography 16 Zoogeography 16 Climate. 19 Soils 20 Vegetation types 22 Woodlands, savannas and steppes. 22 Moistforest at low and medium altitudes. 24 Wooded steppe with abundant Acacia and Commiphora. 24 Sub desert steppe 24 Desert. 24 Montane evergreen forest. 25 Montane communities - undifferentiated 25 Afro-alpine communities. 25 Temperate and subtropical evergreen forest. 25 Mangroves. 25 II. Ecological zones of Africa. 26 The use of ecosystems by man. 28 The ecosystem concept The savanna environment, an example of a man-influenced ecosystem Derived savanna. 30 Breakdown rif organic material Adaptations rif animals to the savanna environment. 31 Biomass and production rif consumers. 32 The Guinean zone 33 The Sudanian zone. 40 The Sahelian zone 43 The Saharian zone. 57 The Mediterranean zone. 60 The Eastern zone. 68 The Zambezian zone. 77 The Transvalian zone. 83 The Basutolian zone. 89 The Kalaharian zone. 93 6

7 The Karroo-Namaqualian zone. The Cape zone III. Man as an environmental agent Primitive man's influence on the environment. 102 Primitive man's use of fire. 102 Primitive man as a cultivator Primitive animal husbandry Implications of the impact of primitive man's influence 104 Modern man's influence on the environment 105 Implications of the human population explosion. 107 Effects of fire on the environment. 110 Fire and soil conservation III Fire as a tool III Effects of agriculture on the environment 112 Traditional systems of land use Modern systems of land use The rehabilitation of the Kikuyu lands. 113 Variations in the cultivability of land 114 Problems of shifting cultivation. 115 Subsistence farming The irifluence of colonial powers 118 Cash crop production The ground-nut scheme failure in Tangarryika 121 What are range lands? Effects of overgrazing on range lands Effects of degradation of environment on the productivity of wild herbivorous animals Land use and soil erosion IV. Specific envirodldental problem.s 128 Nomadism and consequences ofsedentarization. 128 Livestock carrying capacity and land requirements of pastoralists. 129 Ecological consequences of sedentarization. 130 Margina11ands Arid land management problems The problem of desertification The invasion of Africa by plants and animals 135 Introduced plants Introduced animals The preservation of endangered species The need for preservation of natural vegetation 140 The special need for forest reserves The environmental values of forests The need for national parks or equivalent reserves

8 Animal influences on the grassland environment. 144 The role of termites and termitaria 145 The role of the tsetse fly: Africa's boon or bane?. 148 The ecology and control of the desert locust 151 The role of the goat Wetlands, estuaries and mangrove swamps 155 The pesticide problem. 158 Land tenure problems. 160 v. Problems, needs and potentials in land use. 163 Agriculture 163 Problems. 163 The 'Green revolution'. 165 Needs and potentials. 166 Future trends 168 Range and pasture management 169 Range management on arid lands. 169 Prospects and potentials 170 Pasture management. 171 Prospects and potentials 171 Animal husbandry 173 Problems. 173 Needs and potentials. 175 Future trends 177 Forestry. 177 Forest production. 177 The value of shelterbelts 179 The use qf trees in rejuvenating the soil in dry tropical zones 180 Afforestation 180 Future trends and needs 181 Inland fisheries. 182 Problems. 182 Trends, needs and potentials. 185 The fisheries of the Great Lakes of East Africa, a special problem. 186 Wildlife. 187 Problems. 187 Trends, needs and potentials Soil and water conservation 193 Soil conservation and erosion control. 193 The control of wind erosion. 195 Soil fertility and crop management. 196 Green manures and mulches. 196 Reclamation of eroded and abandoned land 197 Development qf water resources. 198 Irrigation developments

9 Water utilization problems.... Problems in river basin development. Prospects in river basin development. Food, health and nutrition VI. Planning for the future. 215 The need for regional planning. 215 Ecological considerations in land use planning. 216 Introduction The need for eco~stem planning Industrial development Environmental qualiry considerations. 221 Ecological constraints to man's future in Africa. 222 Planning for development: a positive approach to more efficient land use