旅游干扰对九寨沟冷杉林下枯落物及其土壤水文功能的影响

Impacts of Tourist Disturbance on Litter and Soil Hydrology Functions of Abiesfargesiivar.faxoniana Forest in Jiuzhaigou,Sichuan

在野外调查和室内分析的基础上,研究了旅游干扰对九寨沟冷杉林下枯落物及其土壤水文功能的影响。结果表明:旅游干扰显著降低了九寨沟冷杉林下枯落物厚度、单位面积最大持水量、最大持水率、自然持水率、有效拦蓄率和有效拦蓄量(p<0.05),与未干扰区相比较,干扰区枯落物厚度、单位面积最大持水量、最大持水率、自然持水率、有效拦蓄率和有效拦蓄量分别降低了40.48%,29.68%,25.21%,49.96%,38.92%和34.29%;旅游干扰下土壤容重显著增加,总孔隙度、非毛管孔隙度和毛管孔隙度减小,土壤持水能力急剧下降;与未干扰区比较,干扰区土壤最大持水率、单位面积最大持水量、有效持水量和土壤含水量分别下降了9.11%,0.34%,12.91%和8.25%,雨季前期含水量、饱和含水量和有效调蓄水空间下降了41.59%,56.01%和44.50%,相同土层基本呈现未干扰区>干扰区,二者的差距随土层深度的增加而逐渐减小或趋于消失,30cm土层以下,干扰区土壤—水文指标基本与对照达到一致,由此表明旅游干扰严重破坏了土壤水文调蓄功能,而破坏作用主要集中在0—30cm土层。相关性分析表明,土壤渗透性能与总孔隙度和非毛管孔隙度均为极显著正相关关系(p<0.01)。

In recent years, tourism has developed rapidly in Jiuzhaigou Nature Reserve which has been desig- nated a World Heritage Natural Site. The impacts of tourist disturbance on litter and soil hydrology func- tions of Abies fargesii var. faxoniana forest in Jiuzhaigou were analyzed based on the field investigation and the laboratory test. The results showed that tourist disturbance significantly decreased the litter thickness, the maximum capacity of soil moisture, the maximum rate of soil moisture, natural moisture rate, the effec- tive rate of interception and the effective capacity of interception（p〈0.05）, which decreased by 40.48%, 29.68%, 25.21%, 49.96%, 38.92% and 34.29%, respectively,compared with non-tourist disturbance area （CK）. Tourist activities destroyed the soil properties severely,compared with CK, the soil bulk density of tourism disturbance area significantly increased, while soil total porosity, capillary porosity and capillary po- rosity significantly decreased. In tourist disturbance area, the maximum capacity of soil moisture, the maxi- mum rate of soil moisture, effective capacity of soil moisture and soil moisture decreased by 9.11%, 0.34%, 12.91% and 8.25%, respectively, the soil moisture of early rainy season, saturated water content and the hydrological spaces decreased by 41.59%, 56.01% and 44.50%, respectively. In the same soil layer, all these factors showed the sequence of CK^tourist disturbance area, while the gap of non-tourist disturbance area and tourist disturbance area decreased with increase of soil depth. Below 30 cm soil layer, all these fac- tors of tourist disturbance area reached the agreement with CK, suggesting that tourist disturbance seriously damaged the function of soil hydrology, and this damage mainly occurred in the 0--30 cm soil layer. Correla- tion analysis showed that soil permeability was significantly positively correlated to soil total porosity and noncapillary poropsity（p〈0.01）.