How do plants and animals depend upon their physical setting and upon one another to live?

Many ways. If there are taller plants associated, then the tall plants could provided shade for a nearby animal, this is especially helpful for a hot day, the animal could suffer a heat stroke. This is one way plants help animals, now, one way animals help plannts, is when an animal dies, it's body decomposes, then providing a type of fertilizer for any nearby plants to grow and become strong and healthy.