华北落叶松人工林蒸腾特征及其与土壤水势的关系  

Relationship between the characteristics of transpiration of Larix principi-rupprechtii forest and soil water potential

作　　者：冯永建[1] 马长明[1] 王彦辉[2] 杜阿朋[2] 

机构地区：[1]河北农业大学林学院,河北保定071000 [2]中国林业科学研究院森林生态环境与保护研究所,北京100091

出　　处：《中国水土保持科学》2010年第1期93-98,共6页Science of Soil and Water Conservation

基　　金：国家自然科学基金项目(40730631;40671038;30671677;40801017);科技部"十一五"科技支撑计划项目课题(2006BAD03A1803);科技部社会公益研究专项(2004DIB3J102);中国林科院中央级公益性科研院所基本科研业务费专项资金(CAFYBB2007038);国家林业局森林生态环境重点实验室资助

摘　　要：利用野外定位观测技术,于2008年5—10月在宁夏六盘山叠叠沟小流域对华北落叶松林整个生长季土壤水势的变化规律进行研究。结果显示：1）降雨量是影响土壤水势变化的主要因素,土壤水势在不同深度变化趋势基本一致,但变化幅度有较大差异,0-20、20-40、40-60 cm土层的土壤水势梯度在6—9月份最大,8月份水势梯度最低;2）华北落叶松5—10月各月的耗水速率排序为6月〉5月〉7月〉8月〉9月〉10月,耗水量分别占生长季的20.3%、25.4%、20.1%、18.6%、15.1%、10.7%,耗水月主要分布在6月;3）在华北落叶松生长季前期土壤水分短缺,生长后期水分充足,2个不同土壤水分条件的树干液流速率表现明显差异,充足条件下蒸腾耗水明显高于短缺条件,且水分亏缺时期20 cm和60 cm土壤水势与树干液流变化相关性极显著。研究表明土壤水分亏缺与否是华北落叶松蒸腾耗水差异的主要原因,生长季中前期土壤水分对华北落叶松生长至关重要。Based on the field observation,the transpiration variation of Larix principi-rupprechtii forest in Diediegou Watershed in Liupan Mountain of Ningxia Province was studied from May to October in 2008.The results showed that the rainfall was the major factor impacting on the soil water potential.Soil water potential in different depth had the similar change tendency,but there were great differences among the variation range.Soil layer in 0-20cm,20-40cm,40-60cm had the biggest water potential gradient from June to September,and the soil water potential was lowest in August.The discending order in water consumption speed from May to October of Larix principi-rupprechtii was June,May,July,August,September,October,and the water consumption was 20.3%,25.4%,20.1%,18.6%,15.1%,10.7% of the growth season respectively.For Larix principi-rupprechtii forest,there was a distinct water shortage happened in earlier stage of growth season,and there was enough water at the later stage of growth season.There was a remarkable difference in water consumption speeds under the different soil water potential. The transpiration in the water enough conditions was higher than in the water shortage conditions significantly,besides,there was a significant relationship between the soil water potential at 20cm and 60cm depths and the sap flow change during the stage of water shortage.It could be concluded that the difference in transpiration consumption is caused by the soil water shortage,and the soil moisture at the earlier stage of growth season is very important for the growth of Larix princip-irupprechtii.

关 键 词：土壤水势 华北落叶松 蒸腾耗水 六盘山 

分 类 号：S152.7[农业科学—土壤学] Q14[农业科学—农业基础科学]