METEOROLOGY Iig 



meteorological conditions. In relation to tsetse flies and other 

 insect pests, the study promises most fruitful results. 



The first detailed studies of ecoclimates in Africa were made by 

 J. Phillips at Knysna in the Union. In 1928 a series of similar 

 studies were started by the Department of Tsetse Research in 

 Tanganyika, and some results have been published in papers on 

 the ecology of tsetse flies, referred to in Chapter X. Since 1931, 

 ecoclimatic studies have been in progress at the Botanical Depart- 

 ment of the Witwatersrand University, in connection with veld 

 studies, and the ecological research on pastures of South Africa 

 inaugurated by Dr. Pole Evans has necessitated further studies 

 which are now in progress. 



T. W. Kirkpatrick (1935), of Amani Research Station, finds that 

 'in most respects the climatic conditions in a coffee plantation 

 differ widely from those that obtain in a standard meteorological 

 screen, and not always in the direction that might on first thoughts 

 have been anticipated'. As an example, the temperature of the 

 outer leaves of a coffee bush may fall in some cases to as much as 

 7° G. below^ the minimum recorded in the meteorological screen. 

 Thus coffee may suffer from the direct effect of freezing, even where 

 no frost has ever been officially recorded. Many other deviations 

 from the standard climate, of a magnitude that undoubtedly exer- 

 cises a great influence on the fauna of a coffee plantation, have 

 been recorded, and some of these are susceptible to at least partial 

 control. 



For biological purposes the study of evaporation is particularly 

 important in connection with the problem of soil erosion and in 

 estimating the effects of forests and other vegetation on rainfall and 

 run-off. Even in South Africa data are very scanty, and for evapora- 

 tion rates the old free-surface evaporimeter is still in official use. 

 In 1923 at the Forest Research Station of Knysna, J. F. V. Phillips 

 introduced Livingston atmo meters of various kinds. These have 

 proved to be greatly superior to the free-surface evaporimeter, and 

 they have subsequently been used in Tanganyika and elsewhere. 



The various potentialities of land can only be fully understood 

 with knowledge of evaporation rates. It is largely through their 

 effects on plant life that climatic changes such as the possible 

 desiccation of Africa affect human beings. Hence the need has 



