This figure illustrates the acceleration of erosion rates following removal of the vegetation. Based on the concentration of cosmogenic isotopes in river sediment, we estimated long-term, natural erosion rates, against which human impact can be measured. Present-day erosion rates were calculated from reservoir sedimentation measurements for 37 catchments; and the fractional vegetation cover of the catchments was estimated from vertical photographs of 1 × 1 m vegetation plots. Our data indicate that vegetation cover exerts first-order control over present-day erosion rates at the catchment scale. Areas with high vegetation density erode at rates that are characteristically similar to those of the natural benchmark, regardless of whether the type of vegetation is native or anthropogenic.
Image 14960 is a 540 by 720 pixel JPEG
Uploaded: Apr28 09