| Virginia
Journal of Science.
2000. Vol 51 (4) : |
| The
Dyke Marsh Preserve Ecosystem David W. Johnston The Friends of Dyke Marsh, 5219 Concordia Street, Fairfax, VA 22032 ABSTRACT
For over a century, Dyke marsh along the Potomac River just
south of Alexandria, VA, has been a favorite site for natural history
studies. Despite earlier attempts at diking to create
agricultural land and dredging for sand and gravel, the remaining marsh
represents the last major tidal freshwater wetland on the upper Potomac
River, and is now owned and maintained by the National Park Service as
the Dyke Marsh Preserve. In the present paper historical data on
physical properties and biota are compared and contrasted with more
recent biological investigations to show functioning ecosystem
components, interrelationships among the flora and fauna, and
documented changes in biotic communities over the years. As a
haven for migratory waterfowl and shorebirds, unique plant communities,
and large, dynamic insect and vertebrate populations, the Preserve is
constantly threatened by river pollution, nearby large-scale
development projects, and bridge construction. The long-term
stability of this unique Preserve depends largely on the vigilance of
the Park Service, concerned citizens, and environmental groups to
ensure the preservation of this valuable functioning ecosystem.Key Words: Ecosystem; Freshwater Wetland; Biotic Communities; Floodplain |