Soil and Vegetation

Abstract

A natural plant cover is in many ways an expression of the effective influences of site, soil and climate. For this reason, the inspection of vegetation has sometimes been regarded as a superior substitute for the study of soils, especially in reconnoitring the agricultural potentialities of undeveloped country. The underlying supposition is that all soil properties that are really significant in the given circumstances will receive expression through the plants, and that any remaining properties can be safely neglected. This supposition is, however, a valid one only in simple cases, which are rather rare; and as the basis of a practical or "commonsense" method of assay it has repeatedly led to mistakes in land utilization, particularly in the exploitation of tropical forests and of natural grasslands. If used uncritically it is liable to fail, firstly because botanical science is not yet equipped to apply it, and secondly because of an imperfect appreciation of the nature of the relationship between plants and soil.