Dr. Monica G.Turner
Department of Zoology
University of Wisconsin
430 Lincoln Dr.
Madison, WI 53706
Landscape Ecology Lab
Ecological indicators and ecosystem function in large river-floodplain landscapes
The Wisconsin River Floodplain project aimed to identify landscape indicators that are well correlated with specific aspects of ecological function is a crucial research need requiring an integrated approach that combines landscape monitoring with field studies. Large river-floodplain systems are among the most diverse and dynamic landscapes in the US, providing many important societal values, but relatively little effort has been devoted to development and testing of landscape indicators for these systems.
We developed and tested ecological indicators for large river-floodplain landscapes along reaches of the Wisconsin River to determine which landscape metrics are most useful for monitoring population, community and ecosystem processes in large river-floodplain landscapes. Spatially extensive field sampling was combined with landscape analysis in nine reaches of the Wisconsin River sampling to quantify the ability of landscape indicators to predict ecological variables over broad scales. Landscape indicators were evaluated by their utility for detecting changes in the structure and function of the Wisconsin River floodplain landscape that were related to modification of the natural flow regime, historical land use, and current land-use patterns. Our field studies were concentrated in floodplain forest in nine 12 to 20-km reaches along the lower 400 km of the Wisconsin River.
The landscape indicators tested in this study explained relatively little of the variability in the forest community structure, the bird community, and soil indicators including denitrification. We hypothesize that this may be due, in part, to the relatively high spatial connectivity of natural habitat types that characterize the Wisconsin River floodplain combined with our focus on sampling within the forest habitat. Landscape indicators may be more important in floodplains in which natural habitats are greatly reduced and fragmented, as has been demonstrated in other landscapes. Furthermore, ecological responses within the river channel (e.g., nitrogen concentrations) may be more sensitive to the occurrence and distribution of gaps in natural habitats that would be reflected in landscape indicators. However, landscape indicators were very useful in exploring alternative land-acquisition scenarios in which relative increases in habitat connectivity for a given increase in habitat extent could be compared.
Funding provided by Environmental Protection Agency STAR Program
Selected Publications (updated April 2008)
Bürgi, M. and M. G. Turner. 2002. Factors and processes shaping land cover and land cover changes along the Wisconsin River, USA. Ecosystems 5:184-201.
Dixon, M. D. 2003. Effects of flow pattern on riparian seedling recruitment on sandbars in the Wisconsin River, Wisconsin, USA. Wetlands 23:125-139.
Dixon, M. D., M. G. Turner and C. Jin. 2002. Distribution of riparian tree seedlings on Wisconsin River sandbars: controls at different spatial scales. Ecological Monographs 72:465-485.
Dixon, M. D. and M. G. Turner. 2006. Simulated recruitment of riparian trees and shrubs under natural and regulated flow regimes on the Wisconsin River, USA. River Research and Applications 22: 1057-1083.
Forshay, K.J. and E.H. Stanley. 2005. Rapid nitrate loss and denitrification in a temperate river floodplain. Biogeochemistry 75:43-64.
Freeman, R. E., E. H. Stanley and M. G. Turner. 2003. Analysis and conservation implications of landscape change in the Wisconsin River floodplain, USA. Ecological Applications 13:416-431.
Freeman, R.E. and R.O. Ray. 2001. Landscape ecology practice by small scale river conservation groups. Landscape and Urban Planning 56:171-184.
Gergel, S.E. 2002. Cumulative impact of levees and dams on the duration of temporary floodplain ponds: a terrain model approach for assessing multiple disturbances at broad scales. Ecological Applications 12:1740-1754.
Gergel, S.E., S.R. Carpenter, and E.H. Stanley. 2006. Do dams and levees impact nitrogen cycling? Simulating the effects of flood alterations on floodplain denitrification. Global Change Biology: 11:1352-1367.
Gergel, S. E., M. D. Dixon and M. G. Turner. 2002. Consequences of human-altered floods: levees, floods and floodplain forests along the Wisconsin River. Ecological Applications 12:1755-1770.
Gergel, S. E., M. G. Turner, J. R. Miller, J. M. Melack and E. H. Stanley. 2002. Landscape indicators of human impacts to river-floodplain systems. Aquatic Sciences 64:118-128.
Kang, H., E.H. Stanley, and S.S. Park. 2003. A sensitive method for the measurement of ammonium in soil extract and water using an OPA compound. Communications in Soil Science and Plant Analysis 34:2193-2201.
Kang, H. and E.H. Stanley. 2004. Effects of levees on soil microbial activities in a large river floodplain. River Research and Management 20:1-7.
Miller, J. R., M. D. Dixon, and M. G. Turner. 2004. Response of avian communities in large-river floodplains to environmental variation at multiple scales. Ecological Applications 14:1394-1410.
Miller, J. R., M. G. Turner, E. H. Stanley, L. C. Dent and E. A. H. Smithwick. 2004. Spatial extrapolation: the science of predicting ecological patterns and processes. BioScience 54:310-320.
Predick, K. I. and M. G. Turner. 2008. Landscape configuration and flood frequency influence invasive shrubs in floodplain forests of the Wisconsin River (USA). Journal of Ecology (In press).
Predick, K. I., S. E. Gergel and M. G. Turner. Effect of flood regime on tree growth in the floodplain and surrounding uplands of the Wisconsin River. River Research and Applications (In press).
Turner, M. G., S. E. Gergel, M. D. Dixon and J. R. Miller. 2004. Distribution and abundance of trees in floodplain forests of the Wisconsin River: environmental influences at different scales. Journal of Vegetation Science 15:729-738.
Turner, M. G., E. H. Stanley, M. Bürgi and D. J. Mladenoff. 2008. Changes in the Wisconsin River and its floodplain. In: D. M. Waller and T. P. Rooney, editors. The vanishing present: ecological change in Wisconsin. University of Chicago Press (In press).