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通过对云南元谋干热河谷人工林地无控制放牧和禁止放牧条件下的土壤水分物理性质的变化对比 ,分析了放牧对幼林地植物生长土壤水分环境的影响。结果表明 ,自由放牧地土壤初始入渗速率较放牧地低 1.3～ 5.2倍 ,并且在 6 0 ,12 0 min供水试验期内累计土壤入渗量分别低 1.9～ 11.9倍和 1.2～ 12 .5倍。自由放牧地土壤持水力也较低 ,特别是有效水含量较禁止放牧地低 19.31%～ 53.83%。因此 ,在干热河谷自然供水有限且与植物需水关键时期不同步时 ,无控制放牧导致的幼林地土壤水分性质恶化是幼树成活和生长的主要阻碍因素之一
By comparing the changes of physical properties of soil moisture under uncontrolled grazing and no-grazing conditions in dry-hot valley artificial forest in Yuanmou, Yunnan Province, the effects of grazing on the soil moisture environment of young plantations were analyzed. The results showed that the initial infiltration rate of grazing soil was 1.3 ~ 5.2 times lower than that of grazing land, and the accumulated soil infiltration rate was 1.9 ~ 11.9 times and 1.2 ~ 12.5 times lower than that of 6 0 ~ 120 min water supply respectively . The water holding capacity of grazing soil is also low, especially the effective water content is 19.31% ~ 53.83% lower than that of no grazing land. Therefore, when natural water supply is limited in dry-hot valleys and unsynchronized to the critical period of plant water demand, the deteriorating nature of soil moisture in young woodlands caused by uncontrolled grazing is one of the major obstacles to the survival and growth of young saplings