text: can you give a very useful meaning of ecology? please?   lets talk animal & plant ecology  first, let's say, all different types of animals & plants live in the same area (maybe  near a river)  in a sense, each animal can depend on each other. for example, the main staple for bears is salmon. let's say man pollutes a river and the fish die. the bear no longer having fish to eat, eat more plants instead. this results in a dramatic decrease of let's say berry plants in one particular area. if you were to move 10 miles upstream, you would be in a separate ecology where the salmons did not die, the bears had a blanced diet and the berry plants were abundant.  bigger ecologies (let's a lake) can literally fall apart and result in the extinction of a particular plant that only grows at that lake.  i hope this was helpful