MACROSYSTEMS ECOLOGY AND HYDROLOGY: WHAT WE HAVE LEARNED AND WHAT WE NEED TO LEARN

Advances in simulation and geospatial technologies have provided unprecedented opportunities to better investigate and understand large ecological and hydrologic systems at regional to continental scales, i.e., Macrosystems. What makes studies of Macrosystems challenging yet particularly intriguing is that components and processes in Macrosystems are unusually complex, characterized by spatial linkages, cross-scale interactions, and feedbacks. In this paper, we present two examples of Macrosystems studies that we have conducted in the broad northern Great Plains for the past ten years or so. The first involves applying an ecological approach (i.e., space-for-time substitution) to understand responses of large hydrologic systems to climate variability. The particular focus is the hydrologic response of Prairie Pothole lakes and wetlands to weather that is remarkably variable from year to year with occasional multiyear droughts and wet periods. The second example highlights preliminary results that demonstrate how a sophisticated hydrologic model (i.e., HydroGeoSphere) has been used to reveal and understand the dynamic spatial linkages or connectivities in wetland habitats. For example, hummocky topography together with the inherent variability in precipitation and temperature produced complex spatial and temporal patterns in the distribution of waterbodies. Results and findings from these two quantitative, interdisciplinary studies are very useful in support of regional and continental water resources management, conservation planning, and policy development.