固沙灌木柠条锦鸡儿和中间锦鸡儿木质部导水与叶片光合能力对土壤水分的响应  

Response of xylem hydraulic conductivity and leaf photosynthetic capacity of sand-binding shrubs Caragana korshinskii and C.liouana to soil water

作　　者：张志山 韩高玲 霍建强 黄日辉 薛书文 ZHANG Zhi-Shan;HAN Gao-Ling;HUO Jian-Qiang;HUANG Ri-Hui;XUE Shu-Wen(Shapotou Desert Research and Experiment Station,Northwest Institute of Eco-Environmental Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Geographical Sciences,Lingnan Normal University,Zhanjiang,Guangdong 524036,China)

机构地区：[1]中国科学院西北生态环境资源研究院沙坡头沙漠研究试验站,兰州730000 [2]中国科学院大学,北京100049 [3]岭南师范学院地理科学学院,广东湛江524036

出　　处：《植物生态学报》2023年第10期1422-1431,共10页Chinese Journal of Plant Ecology

基　　金：内蒙古自治区科技重大专项(2021ZD0008-3);国家自然科学基金(31971529和32301314)。

摘　　要：水分是干旱沙区植被重建和恢复的主要限制性因子,土壤有效水分含量直接影响植物木质部水分运输能力。但是不同水分条件下不同物种、不同年龄木质部水力特性和叶片气体交换的差异以及土壤水分含量对其影响的相关研究目前尚不明确。因此,该研究以10年和30年树龄人工固沙区的柠条锦鸡儿(Caragana korshinskii)和中间锦鸡儿(C.liouana)为实验材料,研究它们在旱季和雨季下水力特性和光合特性的差异及其关系。研究结果表明,树龄对柠条锦鸡儿和中间锦鸡儿木质部导水率、导水率损失百分比、叶片水势和相对含水量等无显著的影响,而土壤水分含量对其功能性状的影响较显著。树龄和土壤水分含量均对灌木叶片光合作用有显著影响,但在土壤水分条件良好的情况下树龄对其影响不显著。此外,土壤含水量与叶片水分含量和木质部茎比导水率之间呈显著的正相关关系;木质部导水率与叶片水分状态和气孔导度也存在显著的正相关关系,而光合速率与木质部导水率和叶片水分含量存在显著正相关关系,这表明土壤水分含量通过影响木质部导水率和栓塞程度而直接影响了叶片水分状况和光合碳同化能力。总而言之,柠条锦鸡儿和中间锦鸡儿的木质部导水能力和叶片光合碳同化能力显著地响应了土壤水分含量的变化。Aims Water is the main limiting factor for revegetation and ecorestrotion in arid sandy areas.Soil available water content directly affects the xylem water transport capacity of plant.However,the differences in xylem hydraulic traits and leaf gas exchange of different shrub species with different ages under varied soil water content are still unclear.Methods The 10-year-old and 30-year-old Caragana korshinskii and C.liouana in the sand-binding area were employed to explore the differences and relationships between their hydraulic traits and photosynthetic traits during the dry and rainy season.Important findings The results showed that the shrub age has no significant effect on xylem hydraulic conductivity,degree of natural embolism,leaf water potential and relative water content of C.korshinskii and C.liouana,while soil water content significantly effects on these functional traits.Both shrub age and soil water content have significant effects on leaf photosynthesis of two shrub species,but the effect of shrub age on them is little significant during the rainy season.In addition,there was a significant positive linear relationship between soil water content with leaf water content and xylem-stem specific hydraulic conductivity.Xylem hydraulic conductivity also had a significant positive correlation with leaf water content and stomatal conductance,whereas net photosynthetic rate was also positive related to xylem hydraulic conductivity and leaf water content.Results indicated that soil water content directly affected leaf water status and the capacity of photosynthetic carbon assimilation by affecting xylem hydraulic conductivity and embolization degree.In conclusion,the change of soil water content significantly affected the xylem hydraulic conductivity and leaf photosynthetic carbon assimilation capacity of C.caragana and C.Liouana.

关 键 词：固沙灌木 木质部导水率 光合特性 水分效应 干旱区 

分 类 号：S793.3[农业科学—林木遗传育种]