ABSTRACT
Energy from rainfall, runoff, and wind disintegrate near surface soil structure (Yoder, 1936; Ellison, 1944; Le Bissonnais and Arrouays, 1997). As soil is transported from eroded to depositional positions across watersheds, aggregate breakdown exposes physically protected soil organic carbon (SOC) pools to mineralization, leading to increased C 02, CH4, and N20 emissions to the atmosphere (Lai, 1995). Some transported material (including SOC, nutrients, and minerals) moves into fluvial waterways (Lai, 1995; Stallard, 1998). In aquatic ecosystems, these materials contribute to eutrophication (Vezjak, 1998; Forsberg, 1998; Frielinghaus et al., 1998; Loweiy, 1998), anoxia (Vezjak et al., 1998; Lowery, 1998), turbidity (Wass et al., 1997; Riley, 1998), and greenhouse gas (GHG) emissions (Lai, 1995). The amount of SOC eventually stored in sediments (Stallard, 1998) of aquatic ecosystems is only a small fraction of transported SOC (Lai, 1995).
