Plant nutrient losses by soil erosion and mass movement after wildfire

摘要: ABSTRACT: Annual sediment yields increased as much 180 times above pre-fire levels after wildfire destroyed all vegetation on three forested watersheds in the Entiat Experimental Forest eastern Cascade Range of Washington. Sediment was transported debris torrents, suspension, and bedload. Suspended concentration correlated well with turbidity. Total N losses by erosion processes from a average 0.004 kg/ha/yr to 0.16 kg/ha/yr. Available P 0.001 before fire 0.014 The combined loss Ca, Mg, K, Na an 1.98 54.3 Greatest nutrient occurred mass soil movements (debris torrents). Material deposited alluvial fans represented 13.5 kg/ha total N, 3.4 available P, 3,850 combined. An unmeasured but certainly large quantity rock entered river during flows. Nutrient eroded soil, although greater than solution losses, were insignificant site productivity stability compared physical effects channel scouring associated runoff, higher peak flows, torrents following fire.