树高对马占相思整树水分利用的效应  

Effects of tree height on whole-tree water use of Acacia mangium

作　　者：刘晓静[1] 赵平[1] 王权 蔡锡安[1] 曾小平[1] 

机构地区：[1]中国科学院华南植物园,广州510650 [2]Institute of Silviculture,Shizuoka University,Shizuoka 422-8529,Japan

出　　处：《应用生态学报》2009年第1期13-19,共7页Chinese Journal of Applied Ecology

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-SW-133);国家自然科学基金项目(30428022,30270239,30770328);广东省自然科学基金资助项目(031265,07006917)

摘　　要：利用Granier热消散探针,于2004年观测了华南丘陵坡地常见绿化先锋树种马占相思(22年生)的树干液流,同时监测林冠上方的光合有效辐射、气温、相对湿度和0～30cm的土壤体积含水量.结合树木的形态特征、液流密度和简化的Whitehead&Jarvis公式,分别计算了整树蒸腾、冠层气孔导度和叶面积/边材面积比值,分析了树高对整树蒸腾、冠层气孔导度和叶面积/边材面积比值的影响.结果表明:土壤水分充足时,马占相思整树蒸腾随树高呈二次多项式增加(P<0.01),冠层气孔导度日变化均呈"单峰"格型;在所有光合有效辐射范围内,高树的参比冠层气孔导度和冠层气孔导度对水汽压亏缺的敏感性均高于矮树;叶面积/边材面积比值为(1.837±0.048)m2·cm-2,并与树高呈幂函数关系.随着树木高度的增加,马占相思没有发生明显的水力限制和补偿.By using Granier＇s thermal disslpation probe, me sap now of 14 sampte trees in a 22- year old Acacia mangium forest in hilly land of South China was continuously measured in 2004. Environmental factors including the photosynthetically active radiation, air temperature, and air humidity above canopy and the water content in 0-30 cm soil layer were monitored simultaneously. Combining with the tree morphological features and sap flux density, the whole-tree transpiration, canopy stomatal conductance, and ratio of leaf area to sapwood area were calculated by simplified Whitehead and Jarvis equation, and the effects of tree height on these three parameters were analyzed. The results indicated that under sufficient soil water supply, the whole-tree transpiration increased in a quadratic polynomial way with tree height （P 〈0. 01 ）, and the diurnal variation of canopy stonmtal conductance was of one-peak pattern. Within the measured range of photosynthetically active radiation, taller A. mangium trees had higher reference canopy stomatal conductance and higher sensitivity of canopy stomatal conductance to vapor pressure deficit, compared with the shorter ones. The ratio of leaf area to sapwood area was （ 1. 837 ＋ 0. 048） m2 · cm^-2, and increased in power function with tree height. A. mangium had no obvious hydraulic limitation and compensation effect with its increasing tree height.

关 键 词：马占相思 树高 整树蒸腾 冠层气孔导度 叶面积/边材面积 

分 类 号：Q945[生物学—植物学]