摘要:Geographic or environmemtal factors affecting the distribution of vegetation are many and diverse, often instrically mixed and interdependent.Either singly or in combination,the various geographic factotrs may affect the presence or absense of various plant community. Alhough it is enormously complex,the immediate vehicles of influence are limited, being light, temperature, water, mineral food, oxygen, carbon dioxide.Except the last two ones being comparatively stable on the globe, the former four ones are affected by the following geographic factors: