Ecosystems: Nature Working Together

An ecosystem is a community of living things — plants, animals, fungi, and microscopic organisms — together with the non-living environment they depend on: the soil, water, sunlight, and air around them. The key idea is that everything in an ecosystem is connected, constantly interacting, exchanging energy and nutrients with everything else.

Scientists split an ecosystem into two parts. The living parts — every plant, animal, fungus, and microbe — are called biotic. The non-living parts — sunlight, temperature, water, air, and minerals in the soil — are called abiotic. Both matter enormously: a desert and a rainforest have very different abiotic conditions, which is why such different living things thrive in each.

Within an ecosystem, every species plays a role, a bit like a job in a busy town. Trees provide shelter and food. Bees pollinate flowers so plants can make seeds. Earthworms break down dead leaves and enrich the soil. Predators keep the numbers of other animals in balance. Because everything is linked, removing just one piece can make the whole system wobble.