Abstract

Linking Landscape and Water Quality in the Mississippi River Basin for 200 Years

Two centuries of land use in the Mississippi River watershed are reflected in the water quality of its streams and in the continental shelf ecosystem receiving its discharge.  The most recent influence on nutrient loading, from intense and widespread farming and especially from fertilizer use, has had a more significant effect on water quality than the conversion of native vegetation to cropland and grazing pastures, or of land drainage. The 200-year record of nutrient loading to offshore water is reflected in the paleo reconstructed record of plankton in dated sediments. The development of fair and sustained management of both inland and offshore ecosystems is thereby linked. The watershed is fully occupied and under the spell of the social policies that can be modified for better or worse, but which will probably change only gradually because of the strong buffering capacity of the soil ecosystem.