UPPER MISSISSIPPI RIVER SYSTEM HABITAT NEEDS ASSESSMENT.

Charles Theiling, Carl Korschgen, Hank DeHaan, Timothy Fox, Jason Rohweder, and Larry
Robinson.  U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse,
Wisconsin 54603.

The EMP Habitat Needs Assessment was designed to help guide future habitat protection and
restoration efforts on the UMRS.  To identify habitat needs, historical, existing, forecast, and
desired future conditions were compared.  Issues of scale are important in this regard because
ecological processes and needs vary at the system, reach, and pool levels.  In addition, a wide
variety of habitat characteristics must be addressed including habitat fragmentation, connectivity,
and diversity.  To accomplish this assessment, a GIS tool and a new floodplain vegetation
successional model were developed.  These tools allow geomorphic and land cover
characteristics to be translated into the potential for species to occur.  Over time, the landscape,
land use, and hydrology of the Upper Mississippi River and its basin have changed.  Much of the
grasslands, wetlands, and forests have been converted to agriculture use, which now accounts for
50 percent of the floodplain.  Impoundment, channelization, and levee construction have altered
the hydrologic regime and sedimentation patterns, resulting in loss of backwaters, islands, and
secondary channels.  While future changes in broad geomorphic features are expected to be
relatively small, habitat degradation is expected to continue.  There is a broadly recognized need
among resource managers and scientists for improved habitat quality, increased habitat diversity,
and a closer approximation of pre-development hydrologic variability.

The Habitat Needs Assessment identified clear differences in habitat types and conditions among
river reaches.  Those differences are largely related to the amount and distribution of public land,
degree of floodplain development, the geomorphic form of the river, and the effects of
impoundment for navigation.  The differences also suggest that habitat needs and restoration
objectives will vary by river reach and pool. 

The Habitat Needs Assessment yielded gross quantitative and qualitative estimates of habitat
needs both system-wide and within river reaches.  These estimates provide the first
approximation of a set of system-wide objectives for habitat protection and restoration.  While
they do not offer quantitatively precise goals, they will help focus future planning on the most
important geomorphic processes both system-wide and in specific river reaches.  However,
perhaps the greatest contribution this first Habitat Needs Assessment has made is the
development of new and improved tools for future habitat planning.  In particular, the GIS Query
tool will help evaluate the potential distribution of species and habitat area types throughout the
UMRS.  While the results of the Habitat Needs Assessment are not a substitute for the more
detailed and spatially explicit planning that will be done at the pool scale, it has provided new
tools for that planning.

Keywords:  GIS, landscape analysis, restoration