The global ecosystem depends on both plants and animals to survive -- and as part of that ecosystem, plants and animals need each other. Although their symbiotic relationship is sometimes subtle, at other times their impact on one another is striking.

Plants and animals benefit each other as members of food chains and ecosystems. For instance, flowering plants rely on bees and hummingbirds to pollinate them, while animals eat plants and sometimes make homes in them. When animals die and decompose, they enrich the soil with nitrates that stimulate plant growth.

Many relationships between plants and animals are mutually beneficial. For instance, flowers need hummingbirds to pollinate them, just as hummingbirds need the flowers' nectar to refuel.

Plants provide a global benefit to animals by releasing oxygen into the atmosphere. Although pollination and food chains affect only a few local plants and animals, they frequently overlap to form larger food webs that contain hundreds or even thousands of wildlife species. This global significance means that when one plant or animal goes extinct, many others suffer as a result.