不同林地清理方式对杉木幼林生态系统水土流失的影响

利用径流小区定位观测法对不同林地清理方式林地的水、土、肥流失及产流过程进行的６年定位研究结果表明：不同林地清理方式导致了林地水、土、肥流失的较大差异。随时间推移，这种差异在缩小。林地缺少采伐剩余物覆盖及炼山时有机质烧失是炼山林地严重水土流失的重要原因。在影响南方杉木造林地水土流失诸因子中，炼山是首要因子。

EFFECTS OF DIFFERENT FOREST GROUND CLEARANCES ON THE SOIL EROSION OF THE ECOSYSTEM OF YOUNG CHINESE FIR FOREST

Through the method of fixed position observation of the run-off plots, the losses of water, soil and nutrients of the forest land of different forest ground clearances have been studied for six years. The results show that different forest ground clearances (control burning and non-burning) result in great difference of soil erosion. As time goes on, the difference decreases. The losses of water, soil and nutrients of the land of control burning within six years are 8767.32m3. hm₂, 38.004t / hm₂ and 523.161 t/hm₂ respectively. The annual losses of soil erosion decrease as the degree of ground cover increases. The first two years after control burning are a key period for controlling the soil erosion at the control burning site. The factors that affect the soil erosion of the ecosystem of young Chinese fir forest are analyzed through applying a mixed quantification theory's model I. The results indicate that the most important factor is control burning.