重庆四面山水源涵养林土壤抗冲性及影响因素

采用原状土冲刷水槽法对重庆四面山4种水源涵养林土壤的抗冲性进行试验研究,并探讨土壤抗冲性动态变化规律以及坡度、根系的影响。结果表明:楠竹林土壤抗冲性最大,其次为针阔混交林、针叶林,阔叶林最小,其抗冲刷系数分别为20.153、14.717、10.819和4.615 L.min/g;林地土壤抗冲性A0层强于A层,并随水流冲刷时间的延长呈指数函数增大;在研究范围内,25°是林地土壤抗冲性的转折坡度;<3 mm根系是四面山水源涵养林表层土壤根系的主要成分,林地A0层土壤抗冲性受<1 mm、1～3 mm、3～5 mm根系根量及死生物量的影响,A层主要受3～5 mm根系根量及其根长的影响。

Soil anti-scouribility of water conservation forests and its affecting factors in Simian Mountain,Chongqing City

Soil anti-scouribility for four different water conservation forests in Siman Mountain of Chongqing was studied by the flume experiment. Also its dynamics over time and its influencing factor including slopes and root system was discussed. Results indicate that： Soil anti-scouribility of Phyllostachys pupescens land was the best, followed by conifer ＋ broadleaf forest land and conifer forest land, the worst was in broadleaf forest land. Soil anti-scouring indices in turn were 20. 153, 14. 717, 10. 819, 4.615 L. min/g. Soil anti-scouribility of A0 was much better than A, and it occurred an exponential relation over time. The 25~ was a turning point of soil anti-scouribility. The roots of 〈 3 mm were the main component of surface soil in this area, therefore soil anti-scouribility of A0 was affected by the root biomass of 〈 1 mm roots, 1 - 3 mm roots and 3 - 5 mm roots and by the root dead biomass, and soil anti-scouribility of A was affected by the root biomass of 3 -5 mm roots and by the root length of 3 - 5 mm roots