对长江三角洲森林生态定位站北亚热带次生毛竹林枯落物水土保持功能进行了模拟研究。结果表明:(1)在室内人工模拟降雨条件下,坡度和雨强是影响坡面侵蚀的重要因素,随着坡度和雨强的增大,泥沙浓度也不同幅度的增大;(2)坡度为5°、10°、15°、20°、26.5°时,裸露坡面和覆盖凋落物的坡面比较,随着坡度增加,覆盖有枯落物的泥沙浓度增幅明显减小,且减少幅度为52.9%~87.1%;(3)在室内人工模拟降雨条件下,雨强为10~50mm/h时,有枯落物覆盖的土壤侵蚀量比裸露坡面分别减少35.58 g/m2、66.82 g/m2、130.32 g/m2、190.62 g/m2和256.16 g/m2。覆盖凋落物的坡面径流量增大幅度相比裸露坡面低25%左右。因此,毛竹林地枯落物可以减少水土流失,有较好的保水保土作用,对控制水土流失有显著效果。
The simulated experiments were conducted to study the functions of litters of north subtropical secondary bamboo(Phyllostachys edulis) on the soil and water conservation at the Forest Ecosystem Research Station of Yangtze River Delta.The results showed that under the condition of indoor simulated rainfall,the slope gradient and rainfall intensity were the important factors in slope erosion.With the increases in slope and rainfall intensity,the sediment concentrations were increased in different extents.Compared with the bare soil,the sediment concentrations in the soil covered with litters were significantly reduced in different slopes.The extent reduction was 52.9%-87.1%.Compared with the bare soil,when the different rainfall intensity was from 10 to 50 mm/h,the soil erosion in the slopes covered with litters was decreased 35.58 g/m2,66.82 g/m2,130.32 g/m2,190.62g/m2,and 256.16 g/m2 respectively.The amplitude of runoff in the slope covered with litters was reduced 25% compared with in bare slopes.So,the litter could play a very good role in increasing infiltration and reducing soil erosion and had a significant effect on water and soil conservation.