水土保持林中枯落物的作用

林地枯落物对改良土壤、截持降雨、减少雨滴溅蚀、防止水土流失等都具有重要作用。人工模拟降雨试验表明,搂去枯落物的林地,将使径流系数增大75％,最大径流流量增加58％,径流含沙量增大6.3倍,土壤侵蚀量增加12.95倍。在水保林经营活动中,应重视枯落物的作用,严禁搂去林地枯落物。在水保林树种选择上应考虑其生产枝叶的能力,或采用针阔混交配置,以使水保林更好地发挥其生态功效。

Effect of Withered Branches and Dead Leaves in the Forest for Soil Conservation

Withered branches and dead leaves in the forest play an important role in amelioration of soil, interception of rainfall, reduction of splashed erosion of raindrop and control of soil loss. The experiment of artifi- cial simulation of rainfall indicates that when dead-leaves are raked up, the runoff coefficient and the maximum discharge in the forestland will increase 75 and 58 per cent respectively, the sediment content of the runoff and the amount of soil erosion will increase by 6. 3 and 12. 95 times respectively. Therefore, we should pay attention to the effect of dead-leaves and strictly prohibit raking up the dead-leaves in the management of forest for soil conservation. Selection of tree species for soil conservation should consider the a-bility of producing branches and leaves or adopt a disposition with coniferous tree and broad-leaves tree in order to make full use of the ecologic function of forest for soil corservation.