Riparian Marshes


A marsh is a type of wetland dominated by herbaceous rather than woody plant species. Marshes commonly are found at the edges of lakes and streams where they form a transition between the aquatic and terrestrial ecosystems. They often are dominated by grasses, rushes, or reeds. If woody plants are present, they tend to be low-growing shrubs. This form of vegetation is what differentiates marshes from other types of wetlands such as swamps, which are dominated by trees, and bogs, which are wetlands that have accumulated deposits of acidic peat. 

Riparian zones provide wildlife habitat, increased biodiversity, and wildlife corridors, which enable aquatic and riparian organisms to move along river systems and helps prevent isolated communities. These wetlands also provide forage (emergent aquatic plants, or herbs, trees and shrubs that thrive in proximity to water) for wildlife and livestock. These zones are important natural biofilters, protecting aquatic environments from excessive sedimentation, polluted surface runoff, and erosion. They supply shelter and food for many aquatic animals, and they provide shade which is an important part of stream temperature regulation. Marshes which occur along rivers are called riparian marshes. 

These marshes serve two ecological roles: to absorb excess water when river levels are high and to release water when river levels are low. These balancing forces help prevent floods and droughts. For the past 100 years, however, mankind has straightened and deepened rivers in order to make them more accessible for commerce. The unfortunate side effect of this is the loss of riparian marshes. Today, very few riparian marshes are left. Some scientists believe that the great Mississippi River flood of 1993 was worsened, in part, by the loss of these wetlands.