14 BRITISH PLANTS 
8. The Nature of the Soil.—From a purely climatic 
point of view, the soil is not important, but ecologically 
it is important because it forms the abode of the vegeta- 
tion. Climate may determine in broad outlines the 
geographical aspects of the vegetation, but the diversity 
of the flora in particular areas is the result, not of differ- 
ences in the climate, but of differences of interaction 
between soil and climate. What these interactions are 
will be made plain when we have considered the properties 
of the soil, and the relations of the various kinds of soils 
to the available supply of heat and moisture (Chapter I X.). 
