外来引种树种大叶相思和柠檬桉树干液流和蒸腾耗水的季节变异  

Seasonal variations of sap flow and transpiration water consumption of introduced tree species Acacia auriculaeformis and Eucalyptus citriodora

作　　者：孙振伟[1,2] 赵平[1] 牛俊峰[1] 倪广艳[1] 朱丽薇[1] 高建国[1] 赵秀华[1,2] 张振振 周娟[1,2] 

机构地区：[1]中国科学院华南植物园,广州510650 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2014年第10期2588-2595,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41030638;41275169;31170673);广东省自然科学项目(S2012020010933)资助

摘　　要：为明确华南地区大叶相思(Acacia auriculaeformis)和柠檬桉(Eucalyptus citriodora)水分利用特征的季节动态变化,利用Granier热消散探针对广东地区两种引进乔木的树干液流进行了连续的长期监测,并同步监测了样树周围的环境因子。结果表明:2种乔木的液流在任何季节都表现出明显的昼夜变化规律,大叶相思的液流峰值和均值都显著高于柠檬桉;液流与环境因子之间的时滞关系因树种和季节的差异而有所不同;光合有效辐射、水汽压亏缺、空气湿度、气温均与液流速率显著相关,冬季光合有效辐射为主导因子,夏季水汽压亏缺为主导因子;比较径级相同、边材面积相似的大叶相思和柠檬桉发现,前者的日蒸腾耗水量显著大于后者,大叶相思蒸腾耗水的季节差异要比柠檬桉更加显著;研究还发现,柠檬桉的边材厚度随年龄的增长而下降;从蒸腾耗水能力的差异可以看出,20世纪80年代中期种植的柠檬桉显然比同龄大叶相思衰退更快。By the method of Granier＇ s thermal dissipation probe, the sap flow density o～ two exotic tree species （Acacia auriculaeformis and Eucalyptus citriodora） in South China was contin- uously measured in 2013, and the environmental factors including photosynthetically active radia- tion （PAR）, soil water content （SWC）, air temperature （T） and air relative humidity （RH） were measured simultaneously, aiming to characterize the seasonal variations of water use in the two tree species. Obvious diurnal variation patterns of sap flow for both species were observed in any season, yet the average and maximum flow rates were consistently higher in A. auriculaefor- mis than in E. citriodora. Cross-correlation analysis showed that the time lag was correlated with tree species and seasons, and sap flow rates were significantly correlated with PAR, T, RH and water vapor pressure deficit （VPD）. PAR and VPD were the dominant factors in winter and sum- mer, respectively. With similar sapwood area and diameter in breast height, water consumption of A. auriculaeformis was significantly higher than that of E. citriodora. Seasonal variation of transpiration in A. auriculaeformis was more significant than that in E. citriodora. Sapwood depth in E. citriodora decreased rapidly with age, which resulted in its lower transpiration rate. Thus,the trees of E. citriodora planted in the mid-1980s senesced earlier than their peers of A. auricu- laeformis.

关 键 词：大叶相思 柠檬桉 树干液流 环境因子 蒸腾耗水量 

分 类 号：S715[农业科学—林学]