Bottomland hardwood forests and wet prairies are two of the most endangered ecosystems in Missouri. These riparian ecosystems originally encompassed most of Missouri’s wetlands. Consequently, the Missouri Department of Conservation and several other land-management agencies have undertaken large reforestation and revegetation efforts in riparian areas of Missouri. Revegetation can speed the restoration of bottomland hardwood forest and wet prairies and provide food and cover for wildlife sooner than natural revegetation. An important factor in the success and character of reforestation and natural revegetation efforts is the hydrologic conditions under which trees are planted and grown. The timing and duration of soil saturation and flooding in riparian areas of Missouri often are the primary factor determining species composition and growth rates as different species have different abilities to adapt to anoxic conditions in the root zone. Species composition, vegetative structure, and detritus, in turn, have a large effect on the reproductive, habitat, and energy value of riparian areas to fish. However, with the exception of the Missouri and Mississippi Rivers, very little is known about the hydrology of riparian areas of Missouri.
The hydrologic conditions in riparian areas are particularly dynamic because saturated soils can result from flood inundation, high ground-water levels, precipitation, and ponding caused by poor surface drainage. The impact of these water sources can often vary over short distances with very small changes in elevation and drainage on relatively flat flood plains. While flood tolerance has been determined for many species, the ability to characterize the exposure of plantings to flood inundation and soil saturation at riparian sites is not possible with the current information on riparian hydrology in Missouri. Therefore, methods to quickly map hydrologic character of riparian areas are needed to increase the success of revegetation efforts and guide management of established vegetation.
Soil moisture has a large impact on the species composition and growth rates of riparian vegetation. Therefore, the concurrent measurement of hydrologic variables with species composition and growth rates should provide valuable information and guidance for riparian management and revegetation efforts. Relating species composition and growth rates with the amount of soil moisture and the primary sources of soil water would result in the location of bottomland hardwoods, wet prairies, and individual species in sustainable locations. With detailed information on riparian hydrology, both plantings and vegetation management might be accomplished using techniques similar to the precision farming methods now being used in agriculture. Restoration of appropriate riparian vegetation also has important benefits to fisheries by providing spawning areas, coarse woody debris for in-channel habitat, sediment removal, temperature moderation from shading, energy sources, and refugia for larval and juvenile fish.
This study also would provide new information about the importance of several hydrologic processes in riparian areas of the Midwest. Many hydrologic questions about the relative roles of ground water, precipitation, flooding, and ponding on soil moisture in riparian areas would be addressed in this study to meet the objectives listed above. For example:
(Fig. 1)
Continuous hydrologic data will be collected with electronic data loggers at three sites within the Four Rivers Conservation Area in Vernon County, Missouri (figure 1). One site will be at locations with mature riparian vegetation, and two will be at a site undergoing reforestation/revegetation. Continuous-data sites will be instrumented with three clusters of monitoring equipment including piezometer nests, soil-moisture probes, a stream gage, a floodplain stage sensor, and a rain gage. The instrument nests will be located along ecological and topographic/geomorphic gradients (e.g. bottomland hardwoods to wet prairie or natural levee to back swamp).
Detailed topography will be obtained at all three sites. Soil properties such as particle size and vertical hydraulic conductivity will be measured at several places at each site to characterize the range of soils present along the transects. Soil cores will be collected at each site to identify appropriate depths for soil-property measurements and zones of low permeability that may perch infiltrating water.
Historic stream stage and meteorological data will be used to reconstruct hydrologic conditions in monitored riparian areas. These data will then be used to broaden the study results beyond the period of data collection.
Missouri Department of Conservation
David C. Heimann
U.S. Geological Survey
Water Resources Division
401 NW Capital Drive
Lee's Summit, Missouri 64086
PHONE: (816) 554-3489
FAX: (816) 554-9273
E-MAIL: dheimann@usgs.gov
U.S. Department of the Interior, U.S. Geological Survey
Maintainer: Rita Choate, Webmaster
Updated: August 29, 2003
Privacy Statement || Disclaimer
|| FOIA || Accessibility
URL: http://mo.water.usgs.gov/indep/heimann/fourrivers/index.htm