The environment is all the water, air, plants, animals, rocks, and soils in an area. The environment changes over time. The change occurs as water supplies disappear, as the weather changes, as some plants die off and others grow, and as mountains form and valleys are eroded. There are many environments on earth.
Some environments are dry with very hard soils some are humid with very thick, soft soils.
Some environments are hilly others are flat. Some are deep under water, others are on rocky ground. Some have streams of water some have streams of slowly moving ice. All environments give animals and plants special problems. Dry environments require animals and plants to deal with the lack of water by saving the water they have or by finding ways to get water.