ABSTRACT
This chapter discusses the data available on soil erosion and hydraulic variation associated with deforestation. Common erosion rates in tilled agricultural regions such as midcontinental US, average about 2–3 m./1000 years. Erosion can be estimated from measurements of sediment carried in streams draining the areas. The soil bacteria multiply rapidly after clear-cutting severs the nutrient cycle. Then the released cations enrich the streams and lakes as they flow seaward to cause local eutrophication, just as would be expected if one dumped fertilizers or phosphate detergents into a stream or lake. Theoretically, areas with thick mature soils, much clay and organic matter, and a long geologic history of weathering and rapid soil formation should be the ideal places to log. In the US such places are restricted to the Southeastern states and coastal parts of Pacific Northwest. In the southeast, the deep red lateritic soils of the coastal plain are among the deepest and best developed in the United States.
