黄土高原主要水土保持树种的蒸腾特性  

Transpiration characteristics of major tree species for soil and water conservation in Loess Plateau

作　　者：周晓新[1] 张建军[1,2] 李轶涛[1] 

机构地区：[1]北京林业大学水土保持学院 [2]水土保持与荒漠化防治教育部重点实验室,北京100083

出　　处：《中国水土保持科学》2009年第4期44-48,54,共6页Science of Soil and Water Conservation

基　　金："十一五"课题"黄土高原半湿润区水土保持植被恢复技术试验示范"(2006BAD03A1204);日本住友财团研究助成基金(The Sumitomo Foundation)"中国黄土高原水土保持林蒸发散及合理密度研究"(083085)

摘　　要：采用精度为0.001 g的精密电子天平和露点水势仪对山杨、刺槐、油松和侧柏的叶片保水力、蒸腾速率日变化及叶水势日变化进行测定。结果表明:自然条件下,4树种叶片保水力从小到大依次为山杨、刺槐、油松、侧柏,其叶片分别经过19、41、49和77 h达自然风干状态;各树种日平均蒸腾速率由大到小的顺序为山杨(0.616 mmol/(m2.s))>刺槐(0.605 mmol/(m2.s))>油松(0.318 mmol/(m2.s))>侧柏(0.270 mmol/(m2.s)),日最大蒸腾速率的排序为山杨(1.196 mmol/(m2.s))>刺槐(1.190 mmol/(m2.s))>油松(0.723 mmol/(m2.s))>侧柏(0.704 mmol/(m2.s));4个树种叶水势以清晨最高,中午最低,傍晚又有所恢复,日变化呈波浪形,日变幅以刺槐最大,其次为山杨和侧柏,油松最小;4个树种叶水势与蒸腾速率之间的关系呈负相关,可用对数曲线来拟合;各树种单位叶面积(cm2)的日(以12 h计)蒸腾耗水量由大到小为:山杨(0.48 mm)>刺槐(0.47 mm)>油松(0.25 mm)>侧柏(0.21 mm)。Leaf water conservation capacity, daily changes of transpiration rate and leaf water potential of Populus davidiana, Robinia pseudoacacia, Pinus tabulaeformis and Platycladus orientalis were studied by using precision Electronic Balance with the accuracy of 0.001 g and Dew Point Microvokmeter. The results show that the descending order of the leaf water conservation capacity of four tree species is Populus davidiana, Robinia pseudoacacia, Pinus tabulaeformis, Platycladus orientalis, and it took 19 h ,41 h,49 h and 77 h respectively before the leaf-weight did not decrease in natural condition. The descending order of the average transpiration rate is ： Populuz davidiana （0.616 mmol/（ m^2·s） ）, Robinia pseudoacacia （0. 605 mmol/ （ m^2·s） ）, Pinus tabulaeformis （0.318 mmol/（ m^2·s） ）, Platycladus orientalis （ O. 270 mmol/（ mE. s ） ）, and the daily maximum transpiration rate in the following descending order： Populus davidiana （1.196 mmol/（m^2·s））, Robinia pseudoacacia （ 1.190 mmol/（ m^2·s））, Pinus tabulaeformis （0.723 mmol/（ m^2·s））, Platycladus orientalis （0.704 mmol/（m^2·s））. The diurnal variation of leaf water potential was a waveform curve with the highest in the early morning, the lowest at noon and significant recovery in the afternoon, and its daily variation amplitude is in the following order： Robinia pseudoacacia is the largest, while Pinus tabulaeformis is the smallest, and Populus davidiana, Platycladus orientalis are in the middle. Leaf water potential and transpiration rate are negatively related, and the relationship between them can be fitted by logarithmic curve. Daily transpiring water consumption amount （by 12 h/d） on unit leaf area （by 1 cm^2） of the four tree species is in the following descending order： Populus davidiana （0.48 mm）, Robinia pseudoacacia （0.47 mm） 〉 Pinus tabulaeformis （0.25 mm）, Platycladus orientalis （0.21 mm）.

关 键 词：水土保持林 叶片保水力 蒸腾速率 叶水势 黄土高原 

分 类 号：S157.433[农业科学—土壤学] Q945.172[农业科学—农业基础科学]