Using Aquatic Invertebrates to Delineate Seasonal and Temporary Wetlands in the Prairie Pothole Region of North America
Ned H. Euliss, Jr., David M. Mushet, and Douglas H. Johnson
U.S. Geological SurveyNorthern Prairie Wildlife Research Center
8711 37 Street SE
Jamestown, North Dakota, USA 58401
Abstract: Tillage can destroy or greatly disturb indicators of hydric soils and hydrophytic vegetation, making delineation of tilled wetlands difficult. The remains of aquatic invertebrates (e.g., shells, drought-resistant eggs, and trichopteran cases) are easily identifiable and persist in wetland substrates even when wetlands are dry. Additionally, these remains are not easily destroyed by mechanical tillage. To test the feasibility of using invertebrate remains to delineate wetlands, we used two methods to identify the wetland edge of ten seasonal and ten temporary wetlands, evenly divided between grassland and cropland landscapes. First, we identified the wetland edge using hydric soil and vegetation indicators along six evenly spaced transects in each wetland (our "standard" delineation). We then identified the wetland edge along the same transects using aquatic invertebrate remains as our indicator. In grassland landscapes, delineations of the wetland edge made using invertebrate remains were consistently at the same location or closer to the wetland center as the standard delineations for both seasonal and temporary wetlands. In cropland landscapes, however, many of our invertebrate delineations of seasonal and temporary wetlands were on the upland side of our standard delineations. We attribute the differences to movement of remains during tillage, increased maximum pool levels in cropland wetlands, and disturbance of hydric soils and plants. We found that the elevations of the wetland edge indicated by invertebrate remains were more consistent within a wetland than elevations determined by standard delineations. Aquatic invertebrate remains can be useful in delineating wetlands when other indicators have been destroyed or severely disturbed by tillage.
Key Words: aquatic invertebrates, invertebrate remains, prairie pothole region, resting eggs, shells, short hydroperiod, tillage, wetland delineation
This resource is based on the following source (Northern Prairie Publication 1174):
Euliss, Ned H., Jr., David M. Mushet, and Douglas H. Johnson. 2002. Using
aquatic invertebrates to delineate seasonal and temporary wetlands in
the prairie pothole region of North America. Wetlands 22(2):256-262.
This resource should be cited as:
Euliss, Ned H., Jr., David M. Mushet, and Douglas H. Johnson. 2002. Using
aquatic invertebrates to delineate seasonal and temporary wetlands in
the prairie pothole region of North America. Wetlands 22(2):256-262.
Jamestown, ND: Northern Prairie Wildlife Research Center Online.
http://www.npwrc.usgs.gov/resource/wetlands/inveruse/index.htm
(Version 01JUL03).
Table of Contents
Figures and Tables
- Figure 1 -- The prairie pothole region of North America.
- Figure 2 -- Location of Environmental Monitoring and Assessment Program hexagons in the prairie pothole region of North Dakota.
- Figure 3 -- Distance between invertebrate delineations and standard delineations.
- Figure 4 -- Relative elevations of invertebrate delineations and standard delineations in seasonal wetland SG5.
- Figure 5 -- Relative elevations of invertebrate delineations and standard delineations in seasonal wetland SC2.
- Figure 6 -- Mean standard deviation
of elevations of invertebrate delineations and standard delineations.
- Table 1 -- Types of aquatic invertebrate evidence used in delineating the wetland/upland edge.
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inveruse.zip
( 71K) -- Using Aquatic Invertebrates to Delineate Seasonal and Temporary
Wetlands in the Prairie Pothole Region of North America
