are adequately documented. The system has been developed for use on personal computers and is thus within the reach of most government agencies in Africa.

MONITORING THE SYSTEM

The dynamic nature of African ecosystems was mentioned at the beginning of this chapter. Continent-wide changes in the distribution of forests, savannas, grasslands, and deserts have occurred during the last 18,000 years due to major climatic events. San bushmen monopolizing isolated desert waterholes, iron-age communities deforesting coastal woodlands, and honey-gatherers burning moist savannas have induced subtle but significant fluxes in the distribution and abundance of plants and animals over the past 1,000 years. More recently, the changes brought about by both colonial and independent governments have been more extensive and less benign. Superimposed on these latter changes have been oscillating dry and wet rainfall patterns with intervals of 10 to 20 years.

Any attempt to monitor the status of species and ecosystems must be cognizant of such fluxes. Conservation biologists in Africa seldom occupy research posts for more than 10 years, and few remain at a given station for more than 5 years. Their observations are therefore of limited generality and frequently result in misleading rather than accurate predictions of a system’s behavior. Nature is often counter-intuitive, and the obvious management response to a problem is not always appropriate—it may even produce an effect directly opposite to that intended (Caughley and Walker, 1983). Research is needed to develop a predictive understanding of ecosystem structure and functioning in response to environmental changes and must be linked to monitoring systems that measure the direction and rates of these changes and responses.

There is extensive literature on the philosophy and technology of environmental monitoring. In Africa, much of this is irrelevant. What monitoring is being done varies tremendously in spatial and temporal scales and in duration and precision. Even where detailed long-term studies have been undertaken, few of the results are amenable to statistical analysis and valid interpretation due to faults in their experimental design (O’Connor, 1985). There are simply no reliable sets of data on some of the most critical issues in biotic diversity, such as the reduction of moist forests and the floristic impoverishment of arid lands. The need for a carefully planned international program of biotic diversity analysis and monitoring in Africa is an urgent priority. Without a reliable data base, cost-effective conservation measures cannot be planned. A few examples of successful monitoring activities suggest possible lines of approach.

At continental and regional scales, Red Data Books (RDBs) of plants, animals, and habitats are beginning to provide a valuable first approximation to the monitoring of biotic diversity (Anonymous, 1985). The accuracy and detail of information on many species in these lists are inadequate, but the mere publication of these data leads to critical review and improvement. The 1976 RDB on South African birds was cited in more than 150 papers within 8 years of its publication, and the latest edition (Brooke, 1984) includes the reclassification of 37 of the



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