Abstract :
Serious concerns exist about environmental and ecological degradation from modern agriculture. In response, the US Environmental Protection Agency (EPA) and the US Department of Agriculture have established cooperative research programs in the midwestern USA to evaluate effects of different landscape structures and farming practices on crop yield, movement of agrichemicals, water and soil quality, and biodiversity. This paper develops the hierarchical approach for those efforts particularly in relation to wild plants and animals (invertebrates, birds, small mammals) in terrestrial habitats. The importance of considering different levels of biological organization and types of agricultural Stressors over a hierarchy of spatial and temporal scales is developed and illustrated by studies from North America and Europe. EPA studies of farmland wildlife in the Midwest are used to illustrate an application of the hierarchical approach. Those efforts would be improved by more regionally specific information on effects for a greater variety of taxa and over a broader range of biological organization. Metapopulation dynamics also need study. More detailed studies are required to evaluate specific, alternative within-field management practices, land set-aside schemes, and habitat restoration or enhancement options. Development and linkage of GIS and spatially explicit population models would help develop, evaluate and communicate future scenarios. An opportunity exists in the Midwest programs to compare biological patterns at population, community and landscape levels with assessments of ecosystem processes over a hierarchy of spatio-temporal scales. The potential also exists to develop future scenarios which integrate across ecological, socio-political and economic perspectives. To accomplish this, a more inclusive and consultative approach is required. Changes in existing institutional processes and frameworks are likely required to promote the broad, integrated, transdisciplinary approaches needed for more effective planning, research and management of agricultural landscapes.
