Relationships Between Land Use and Sediment Accumulation in Minnesota Lakes, from Pre-settlement to Present
The native landscapes of Minnesota have undergone enormous transformation since Euro-American settlement in the mid-19th Century. Intensive logging has disturbed areas throughout the northern and eastern portions of the state while near-total conversion of tallgrass prairie into farmland, combined with substantial wetland drainage, has created human-dominated agroecosystems in the south and west. These occurrences and subsequent land use practices have unquestionably altered patterns of soil erosion and subsequent deposition of sediments in aquatic environments. We explore the long-term historical relationships between land use and sediment accumulation in over 100 Minnesota lakes spanning 3 ecoregions and multiple land use regimes, including intensive row-crop agriculture, for the past 150-200 years. Because these lake sediment records provide an integrated signal of environmental change at the watershed scale, they yield important insights into the degree of aquatic impairment by excessive sedimentation and the effectiveness of conservation strategies in controlling sediment erosion.
Robert Dietz, Daniel Engstrom, Shawn Schottler, and James Almendinger