西双版纳热带季节雨林林冠截留雾水和土壤水的关系  

Fog interception and its relation to soil water in the tropical seasonal rain forest of Xishuangbanna,Southwest China

作　　者：刘文杰[1] 李鹏菊[1] 李红梅[1] 张一平[1] 段文平[1] 

机构地区：[1]中国科学院西双版纳热带植物园,云南勐仑666303

出　　处：《生态学报》2006年第1期9-15,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30570308;30100019);国家重点基础发展计划资助项目(2003CB415100)~~

摘　　要：利用2002年1月-2003年12月在西双版纳热带季节雨林观测样地收集的林冠截留滴落雾水、雨水、浅层土壤水和地下水水样，对其氢、氧稳定性同位素比率δD和δ^18O的测定结果进行了分析，研究了林冠截留雾水对土壤水和地下水的影响。干季（11-翌年4月份），热带雨林林冠截留雾水的稳定性同位素比率、过量氘（d-excess）值明显高于雨水的相应值，表明雾水水汽中包含了区域森林植被蒸发、蒸腾的再循环水汽。林下地表浅层土壤水的稳定性同位素比率介于雾水和雨水的同位索比率之间，表明浅层土壤水来源于雾水和雨水的补给，但是干季浅层土壤水包含更多的雾水。在降雨稀少的干季，浅层土壤水主要来自雾水的补给，表明了林冠滴落的雾水是林下幼树和耐阴树种生长和生存的重要环境因子。干季和雨季（5-10月份）地下水的稳定性同位素比率与雨水的均没有显著差别，表明雾水对地下水的补给没有贡献，其水分补给仅仅来自雨水。Intercepted fog water （fog drip） by forest canopy, rainwater, shallow soil water and groundwater were collected during January 2002 and December 2003 for stable isotopic analysis at a tropical seasonal rain forest site in Xishuangbanna, Southwest Ch/na. The object of the study is to determine whether the fog interception has influence on soil water and groundwater. Bottlefunnel collectors were used to determine daily amount of intercepted fog water during fog-only events in the rain forest, and fog drip samples were collected monthly interval. Rainwater samples were collected monthly interval on an event basis, by using a collector consisting of a stainless steel funnel mounted on the top of a 72 m high meteorological tower. Rainwater sample was also collected at each rain event when rainfall exceeded 10 mm at the weather station. Shallow soil samples were obtained randomly within the forest site from cores collected to a depth of 20 cm beneath the canopy on each sampling day. Groundwater was collected monthly from the hand-dug wells located in the forest. The stable hydrogen （δD） and oxygen isotope composition （δ^18 O） of fog drip, rainwater, shallow soil water and groundwater was determined from an isotope ratio mass spectrometer. The results indicated that the fog drip water was thought to contain water that has been evaporated and recycled terrestrial meteoric water （ evaporation of nearby surface waters and canopy interception）. Tile rain was isotopically more depleted. The fog drip was consistently more enriched than the rain during both the dry season and rainy season. The shallow soil water commonly had composition between the fog drip and rain, suggesting that the shallow soil water is a mixture of the two waters. However, the soil water collected in dry season appeared to contain more fog drip water than that collected in rainy season. The detection of fog drip water in the shallow soil indicates that fog drip may in dry season be an important factor in growth and survivability of unde

关 键 词：辐射雾 雾水截留 地下水 土壤水 稳定性同位素 热带季节雨林 

分 类 号：S715[农业科学—林学] S714