黄土半干旱区土壤水分条件对刺槐蒸腾速率的影响  

THE STUDY ON TRANSPIRATION RATE OF THE BLACK LOCUST UNDER DIFFERENT SOIL WATER CONTENT IN SEMI-ARID REGION LOESS PLATEAU

作　　者：张华[1] 郑培龙[1] 王百田[1] 

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

出　　处：《武夷科学》2005年第1期40-46,共7页Wuyi Science Journal

基　　金：国家自然科学基金项目(3007063);国家攻关项目(2004BA510B0304)资助

摘　　要：于2004年夏在山西方山北京林业大学试验基地,采用LI-1600稳态气孔仪,对不同土壤水分条件下盆栽刺槐的生理指标进行了观测。结果表明:黄土半干旱区刺槐蒸腾速率ηt/(μg.cm-2.s-1)与生理辐射强度I/(mol.s-1.m-2)的关系可以表示为:ηt=aIb;蒸腾速率ηt/(μg.cm-2.s-1)、气孔阻力Rs/(s.cm-1)和土壤体积含水量W/%之间存在着密切的关系,分别表示为:ηt=a+bW+cW2,Rs=a+bW+cW2;蒸腾速率一般随光强的增强和土壤水分的提高而增大,刺槐蒸腾速率与土壤水分含量的相关系数平均可达0.8825。通过研究不同土壤水分条件下刺槐蒸腾速率的差异,提出了刺槐水分利用效率的合理供水范围在10%-15%之间,为干旱半干旱地区提高林木的水分利用效率提供了理论依据。This paper mainly analyzed the transpiration characteristic of black locust,the major tree for forestation in the Loess Plateau.Physiological indices of black locust in differentsoil water conditions were measured by portable steady porometer(LI-1600) in the summer of 2004,in Fangshan,Shanxi Province(Forestry Experimental Station of Beijing Forestry University).The response processes of physiological absorbed radiation(I),stomatal resistance(R_s),leaf water potential(ψ) and transpiration rate(Tr) to different soil water content were studied.The results showed,the relationship between transpiration rate and physiological absorbed radiation of black locust in semi-arid regions of loess plateau was obtained as follows: η_t =aI^(b).Meanwhile,the relationship of transpiration rate(η_t) and stomatal resistance(R_s) with soil water content(W) was given as follows: η_t=a+bW+cW^2,R_s= a+bW+cW^2.The interrelationship between transpiration,irradiance and soil water condition was quite remarkable.Generally,the rate of transpiration increased with the raising of irradiance and soil water content.The correlation between transpiration rate and soil water content was close.(average logarithmic relations,R^2= 0.8825).Furthermore,the transpiration rate could rise greatly with the increase of soil water content.Based on the above analysis of the rate of transpiration in different soil water conditions,therefore,to lighten injuring on physiology as transpiration seriously,to increase the rate of survivor and to promote growing,it is necessary to adopt measure as avoiding violent irradiance of the sapling when the soil is short of water.The soil water content as 10%<SWC<15% is beneficial to increase the water use efficiency of plants,which could help plants to enhance water use efficiency in arid and semiarid region.

关 键 词：刺槐 蒸腾 土壤水分 气孔阻力 水分利用效率 

分 类 号：S154.1[农业科学—土壤学]