黄土丘陵半干旱区人工沙棘林水土保持和土壤水分生态效益分析

Ecological benefits of artificial seabuckthorn stands in semi-arid hilly region of Loess Plateauion soil-and water conservation and soil moisture.

沙棘及其混交林减少径流泥沙的作用突出 ,但结构和混交模式不同所发挥的水保作用大小不同 .沙棘林生长季各月消耗利用水分的强度不同 .在整个生长季 ,5月末 0～ 5 0 0cm土层平均含水率最低 ,为5 .1% ;10月末最高 ,达 8.8% .沙棘林对土壤水分的利用强度受林龄影响 ,8龄沙棘林年消耗土壤贮水2 31.2mm ,应进行平茬 .平茬后第 3年末 ,土壤水分恢复深度达 16 0cm ,含水率为 10 .3%～ 14 .6 % .沙棘林具有削减坡位对土壤水分影响的作用 .沙棘及其混交林对土壤水分的利用强度相似 ,林地存在土壤干层现象 .

There is a remarkable function on decreasing runoff and sediment in seabuckthorn and its mixed stands, but the effects on soil and water conservation are different due to different structure and patterns of seabuckthorn and its mixed stands. The intensity of soil water use by seabuckthorn forest was different along with the month in growing season. In growing season, soil moisture in 0～500 cm layer was 5.1%, the lowest in the end of May and 8.8%, the highest in the end of October.This intensity was also different with forest age. 8 ages seabuckthorn forest consumed 231.2mm of soil stored water in 0～500cm layer annually, and soil moisture was 5.6%. Therefore, it should be cut for increasing soil moisture. In end of the third year after cutting, soil moisture in 0～160cm layer could recover,and the value would be 10.3%～14.6%. Seabuckthorn forest could reduce the effect of slope location on soil moisture.Seabuckthorn and its mixed stands have similar intensity of soil water use,and there was a soil dry layer phenomenon in their stands.