Main physical factors
Natural vegetation and wildlife are shaped by four main physical factors: climate, relief, soil and drainage. These factors decide the type and distribution of plants in an area.
- Climate — high temperature and heavy rainfall all year encourage the growth of evergreen tropical rainforest.
- Relief — the height and slope of the land affect plant type; the higher the land, the lower the temperature.
- Soil — deep, fertile soil supports large, tall trees.
- Drainage — the way water flows and drains from the land decides whether an area is waterlogged or dry.
Key idea
The four physical factors affecting vegetation are climate, relief, soil and drainage.
Effect on wildlife
Natural vegetation provides food and shelter for wildlife. An area rich in thick vegetation therefore usually has a greater variety of animals. In waterlogged coastal areas, mangrove vegetation is a habitat for crabs, fish and birds. On cool highlands, montane vegetation becomes home to certain animals. A change in any physical factor will change the type of vegetation, and in turn change the wildlife that can live there. For example, if a forest is cleared, the ground temperature rises and the soil dries out, so the original plants die and animals lose their homes. The four physical factors are therefore closely linked and act together to decide the pattern of vegetation and wildlife in an area. Climate sets the overall conditions, relief and drainage affect moisture, and soil supplies the nutrients plants need. Understanding these links helps us appreciate why protecting the environment is so important for keeping the ecosystem in balance.