Large river-floodplain systems are among the
most diverse and dynamic landscapes, providing many important societal
values; these systems also have been subject to a variety of anthropogenic
stresses primarily due to river flow modification and land use change.
Despite the importance to society of maintaining the integrity of large
river-floodplain landscapes, relatively little effort has been devoted
to their study. Past work, led by Monica
Turner and her lab, has investigated land use change, vegetation, bird
communities, and soil properties of the Wisconsin River floodplain.
Our current research, supported by the National Science Foundation, focuses on nitrogen and carbon cycling in the floodplain,
changing composition of the floodplain forest, and the ability of these
systems to act as nitrogen sinks for increasingly N-enriched river systems.
The Wisconsin River is an excellent laboratory
for floodplain research. Like most large river systems (and arguably
all Midwestern U.S. rivers), it is subject to several persistent anthropogenic
influences. Much of the 31,440 km2 basin is used for agriculture,
consequently non-point source nutrient loading is a serious management
concern. Total N concentrations are low (~1-2 mg/L) relative to adjacent
basins to the south (e.g., Rock and Illinois Rivers where nitrate concentrations
in floods can exceed 10 mg/L), yet comparison of measurements made in 2001-2002
to data collected by the USGS NASQAN program (Alexander et al. 1996) indicate
that concentrations have increased by ca. 0.5 mg/L in the past decade.
Despite anthropogenic influences, extensive forested floodplain areas are
present in the Wisconsin River floodplain, and in fact have expanded since
the 1930s (Bürgi & Turner 2002, Freeman et al. 2003). Forests
cover ~60% of the 100-year floodplain, and >80% of the habitat immediately
adjacent to the river channel.
The Wisconsin River has a long history of
ecological research and musing. Of particular note, the river and
its floodplain provided a holiday escape for Aldo Leopold and his family
during the 1930s and 1940s. Leopold wrote "A Sand County Almanac"
at the Leopold Shack. We are fortunate to benefit from partnerships with
conservation groups carrying on the Leopold legacy- the Sand
County Foundation and the Aldo
Leopold Foundation- as we pursue our work on the Wisconsin River.
