The troubled ark of planet earth

Press, 30 May 1987, Page 23

The troubled ark of planet earth

State of the Ark. By £m Durrell. Bodley Hoad, 1988. 224 pp. Illustrations. $39.95. (Reviewed by IV. R. PhHipson) The coffee-table format, with illustrations on nearly every page, helps the reader to swallow some very unpalatable facts. This attractive and easily read book is, in effect, a text book on the conservation of the earth’s resources.

It opens with a beginners guide to ecology, including explanations of the dependence of the photosynthesis of plants on the energy of the sun, how this is the basis of all food chains, and the need to keep whole ecosystems intact, including the “planetary lifesupport systems” of air, climate, soil, and water. Emphasis throughout is on facts. The text is supplemented not only with maps and charts, but is reinforced with relevant case studies of appropriate organisms, ecosystems, or examples of human intervention. Indeed, the greater part of the book is taken up with these, the text itself occupying less than a third of the pages. The introduction to the biosphere and the man-induced pressures on it, such as erosion, pollution and deforestation, is followed by a series of chapters surveying the present state of the ark. The major types of living communities — forests, grassland, tundra, deset, wet land, rivers, lakes and ocean — are all under threat of over exploitation. The long-term

results of present trends are considered, as is the effectiveness of the conservation of habitats by various protective regulations or by segregating them as National Parks. Crops are becoming increasingly standardised so that the genetic diversity present in wild populations forms a vital reserve. In spite of this, the rate of extinction accelerates, and with each species lost irretrievable

genetic material perishes. The loss of any species may have unexpected repercussions. The people of the Amazon, for instance, depend for protein largely on fish, and many of these fish, in turn, feed for much of the year on fruit falling from the trees growing in the periodically flooded forest. With the clearing of great areas of forest, this source of food has disappeared and the fish population has fallen correspondingly, a serious loss for the 700,000 inhabitants of Manaus, for there is no longer forest within 100 km of this city. Pollution over-rides national boundaries with oil slicks at sea and air pollution drifting as acid rain, so conservation requires international agreements regulating industrial wastes. Since the biosphere takes no account of political boundaries, agreements are also needed to regulate the exploitation of wild life for zoos, for experimentation, or for their products such as skins or ivory. The part played in this by

Greenpeace has been outstanding and is entering a new phase as Antarctica is threatened. The final chapter, which discusses the many types of organisation, local and global, concerned with conservation in its many aspects, is the most original part of this book. A wide range of approaches allows everyone an opportunity to take some part in the conservation movement

The maps add greatly to the usefulness of the book, but they could have been improved with a more judicious choice of colo.urs. These are so indecisive that it is difficult to match the keys with the maps themselves, a task made impossible on the map of biomes (p. 41) by the lack of correspondence between the key and the map. In a book so packed with factual material I have detected few inaccuracies, the most unfortunate being the use of the wrong illustration on p. 143 (Erythronium in place of the rare buttercup referred to in the text). The over-all lesson which emerges is one that the author advances, but does not care to emphasise. Whatever success we may have in the production and fair distribution of the world’s supply of food and other necessities will be frustrated if the population continues to increase. Since food production is finite, and fertile land continually decreasing, the surest hope for a reasonable living standard for all is to halt the growth in population.