Wetland Ecosystems

This section will define and describe wetland ecosystems. Specifically, you will learn:

What is a Wetland Ecosystem?
What do we mean by wetlands? What bodies of water comprise wetlands?

While wetlands are vital to the life of a lake, river or ocean, they don't have the physical appeal of their attractive neighbors. Typically wetlands include marshes, swamps, bogs and other marshy areas--any area where water covers the soil for at least part of the year. There are two types of wetlands: coastal or tidal wetlands and inland or non-tidal wetlands.

Like the other water ecosystems, wetlands have numerous sources for their water. Their contiguousness to other bodies of water makes them a natural sponge for holding excess water from lakes, rivers or oceans. Rain and groundwater also contribute to wetlands, depending on the amount of rain and the level of the groundwater. Although they are not the ending point of any water source, wetlands are a vital part of a watershed because they connect land and water resources, acting as a purifier for larger water resources. Many watershed protection programs include protection for wetlands.

Wetland Chemistry
In general, wetlands vary in chemistry depending on their habitat. For example, coastal wetlands contain chemicals native to the ocean, while inland wetlands house chemicals from freshwater sources. Since wetlands soak up nutrients from the surrounding water and soil, chemical makeup always varies, but wetlands contain higher chemical concentrations than either oceans or freshwater habitats do.

Because wetlands are an important part of the watershed, several factors can endanger both the wetland and its surrounding aquatic ecosystem:
· Removing the wetlands by adding soil to the surface water to fill it in
· Large amounts of point source or nonpoint source pollutants
· Removing the plant life from the wetland or its surrounding area

Why We Need Wetland Ecosystems
What do wetlands do to maintain water quality in general?

Wetlands function as "supermarkets" for all of the living plants and animals in the watershed. Dead plants form nutrients (detritus) that feed small aquatic insects and herbivorous fish and shellfish. Larger fish from lakes, rivers and oceans feed off of the smaller fish and insects. Wetlands, therefore, serve as the beginning part of the aquatic food web. In addition, wetlands serve as a habitat for species like the wood duck, as well as several endangered species.

Other aquatic ecosystems need wetlands for their sponge-like function, storing excess water and slowly releasing it, preventing floods and reducing erosion. In addition, wetlands catch wastes and sediment before they reach the water and retain their nutrients.

Wetlands also store carbon from the plants and soil that surround them, helping to moderate climate and atmospheric conditions.