Freshwater Biology (1997) 37, 149161
SPECIAL APPLIED ISSUES SECTION
The influence of catchment land use on stream
integrity across multiple spatial scales
J . D AV I D A L L A N , D O N N A L . E R I C K S O N A N D J O H N FAY
School of Natural Resources and Environment, The University of Michigan, Ann Arbor MI 481091115, U.S.A.
S U M M A RY
1. Despite wide recognition of the need for catchment-scale management to ensure the
integrity of river ecosystems, the science and policy basis for joint management of land
and water remains poorly understood. An interdisciplinary case study of a river basin
in south-eastern Michigan is presented.
2. The River Raisin drains an area of 2776 km2, of which some 70% is agricultural land.
The upper basin consists of till and outwash, and both topography and land use/cover
are diverse. The lower basin consists of fine textured lake deposits, is of low relief, and
land use is primarily agricultural.
3. The River Raisin basin historically was a region of oak-savannah and wetlands. It
was deforested, drained and converted to farmland during the mid-nineteenth century.
Human population reached a plateau at about 1880, and then underwent a second
period of growth after 1950, mainly in small urban areas. More recently, the amount of