Interdependence and competition

• To survive and reproduce, organisms require a supply of materials from their surroundings and from the other living organisms in an ecosystem.
• Plants often compete with each other for light and space, and for water and nutrients from the soil. Animals often compete with each other for food, mates and territory.
• Within a community each species depends on other species for food, shelter, pollination, seed dispersal etc. If one species is removed it affects the whole community.
• A stable community is one where all the species and environmental factors are in balance so that population sizes remain fairly constant.