When water levels are low, wetlands slowly release water. A marsh in Scotland Wetlands also release vegetative matter into rivers, which helps feed fish in the rivers. Wetlands help to counter balance the human effect on rivers by rejuvenating them and surrounding ecosystems. Many animals that live in other habitats use wetlands for migration or reproduction. For example, herons nest in large old trees, but need shallow areas in order to wade for fish and aquatic life.
Amphibians often forage in upland areas but return to the water to mate and reproduce.
While Wetlands truely unique, they must not be thought of as issolated and independent habitat. To the contrary, Wetlands are vital to the health of all other biomes and to wildlife and humans everywhere. Unlike most other habitats, wetlands directly improve other ecosystems. Because of its many cleansing benefits, wetlands have been compared to kidneys. The analogy is good one.