Burial in the wetland substrate will keep bound metals immobilized. Immense varieties of species of microbes, plants, insects, amphibians, reptiles, birds, fish, and other wildlife depend in some way on wetlands. Wetland plants play an integral role in the ecology of the watershed. Wet land plants also reduce erosion as their roots hold the streambank, shoreline, or coastline. The nutrients and compounds released from decomposing organic matter may be exported from the wetland in soluble or particulate form, incorporated into the soil, or eventually transformed and released to the atmosphere.
Decomposition requires oxygen and thus reduces the dissolved oxygen content of the water.
The inundated or saturated conditions occurring in wetlands limit plant species composition to those that can tolerate such conditions. The shape of the wetland varies the perimeter to area ratio. Shape is also important for the possibility of movement of animals within the habitat and between habitats. Wetland size is particularly important for larger and wide ranging animals that utili ze wetlands for food and refuge, such as black bear or moose, since in many locations wetlands may be the only undeveloped and undisturbed areas remaining.