Vegetation Component, Long Term Resource Monitoring Program
As part of the LTRMP we began monitoring floodplain vegetation within LaGrange Reach of the Illinois River in 1991, focusing on submersed and rooted floating aquatic as well as moist soil and emergent plant communities. Fixed site sampling of submersed aquatic plants (i.e. Coontail and Sago pondweed) is conducted during 2 sampling windows from May through August along 16 transects within 3 isolated backwater lakes, (Spring Lake, "Bulrush Pond" in Banner Marsh, and Point Lake) and one side channel (Grape Island). In 1998, a stratified random sampling design was incorporated to our submersed aquatic sampling regime which involves visiting 550 random sites located in most aquatic areas within the floodplain of LaGrange (i.e, Lily, Anderson, Crane, Chautauqua, Rice, and Pekin Lakes). Moist soil and emergent plant communities as well as forest communities are monitored through remote sensing techniques using colored infrared aerial photography. Aerial photos of LaGrange Reach (and select HREP areas) are interpreted and digitized using a 13 general class land cover/use classification to create Geographical Information System (GIS) maps. These maps can be used in a computer software program (Arcview) with a multitude of applications including calculating total acreage of individual plant communities such as submersed and moist soil. Scanned immages of aerial photos taken of the entire LaGrange Reach in 1994 are available on the USGS Upper Midwest Environmental Sciences Center’s (UMESC) home page.
Forest monitoring
Following the flood of 1993 we began monitoring floodplain forest communities within LaGrange to assess mortality and monitor regeneration of floodplain tree species. Other forest related studies we are involved in include data collection to be incorporated into a computer model that will help in predicting the elevations at which mast tree species will grow. Data such as this could be utilized by a multitude of agencies involved in replanting efforts within floodplain ecosystems including tributary systems such as the Mackinaw River.
