黄土丘陵沟壑区退耕地植被恢复中的土壤水分变化研究

选择了黄土高原安塞县境内的纸坊沟、县南沟、西沟、郭阳湾等不同流域,对黄土丘陵沟壑区退耕地植被恢复过程中的土壤水分变化规律进行了研究.研究结果表明,随着退耕年限的增长,60 cm以下土层的土壤水分含量逐渐减少;对于不同地形条件的土壤含水量,阴坡＞半阴坡＞阳坡,坡下＞坡中＞坡上,并且随着坡度的增大,土壤含水量减小;不同的植被类型土壤水分含量也不同,在选择的草地、灌木地、林地3种植被类型中,以草地的土壤含水量最高,林地最小,灌木地介于两者之间;从恢复方式看,自然恢复的土壤水分含量相对较高,人工恢复的土壤水分含量相对较低,自然+人工恢复介于两者之间.另外,对于同一种植被类型,生物量越大,土壤水分含量越小.

Variation of Soil Water in Abandoned Lands During Vegetation Restoration in Hilly and Gully Regions on Loess Plateau

The variation of soil water in the process of vegetation restoration on abandoned lands in Zhifanggou, Xiannangou, Xigou and Guoyangwan watersheds of the loess hilly and gully region was studied. The results show that soil water content below 60 cm depth gradually decreases with increasing time since land was left to regenerate. Results of the soil water content evaluation for different topographies suggest: the soil water content on north-facing slopes is higher than that on south-facing slopes; the soil water content at the lower slopes of hills is higher than that at upper slopes of hills; and soil water content decreases with the increasing slope gradient. The soil water content under different types of vegetation differs: soil water content under grassland is relatively high and that under woodland is relatively low. Results for soil water content for different vegetation restoration measures suggest soil water content under natural restoration is higher than that under manual restoration. In addition, it was found that the greater the biomass, the lower the soil water content.