Climatic Classification From the Standpoint of East African Biology

Abstract

This paper is an exhaustive and critical review of climatic classifications with special reference to biology. The general criticism is made of existing classifications that they are based upon "normals" while biologically, extremes have very great importance. In an attempt to indicate the type of classification most suitable for a tropical country like East Africa, it is pointed out that the single value factors with a respectable physical basis are rainfall and evaporation. In E. Africa, relief is of equal importance and owing to the scarcity of data in this area, it is suggested that 3 criteria might be used (a) temp., (b) length of influential rainfall period, (c) recorded rainfall of that period. This may prove locally unsatisfactory because it does not take into account (i) climatic extremes (ii) "horizontal precipitation" which appears to be crucial for the existence of much evergreen forest, and (iii) "rainfall effectiveness" depending on the intensity of rainfall and on the nature of the soil.