张掖湿地旱柳叶脉密度与水分利用效率的关系  

Correlation between vein density and water use efficiency of Salix matsudana in Zhangye Wetland,China

作　　者：徐婷[1] 赵成章[1] 韩玲[1] 冯威[1] 段贝贝 郑慧玲[1] 

机构地区：[1]西北师范大学地理与环境科学学院甘肃省湿地资源保护与产业发展工程研究中心,兰州730070

出　　处：《植物生态学报》2017年第7期761-769,共9页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(41461013和91125014)

摘　　要：植物叶脉密度与水分利用效率(WUE)的关联性影响着植物水分的供需平衡,为验证植物进化过程中形成的生态适应策略提供了适用性理论依据。该文选择张掖市黑河干流边缘的洪泛平原湿地为实验地,以河岸为起点沿平行河岸线的方向依次设置近水区(样地Ⅰ)、中水区(样地Ⅱ)和远水区(样地Ⅲ)3个水分梯度样地,结合相关分析和标准化主轴分析,研究了水分影响下旱柳(Salix matsudana)叶脉密度与WUE之间的关系。结果表明:随着土壤含水量减少,旱柳林的高度和郁闭度均持续降低,旱柳叶片的叶脉密度、WUE、净光合速率、蒸腾速率、光合有效辐射和饱和水汽压差逐渐增加,比叶面积、气孔导度和胞间CO_2浓度逐渐减小;不同土壤含水量样地旱柳叶脉密度与WUE间的相关性存在差异(p<0.05),在样地Ⅰ和样地Ⅲ,叶脉密度与WUE呈极显著正相关关系(p<0.01);在样地Ⅱ,两者之间呈显著正相关关系(p<0.05);样地Ⅰ叶脉密度与WUE的相关系数显著小于1,样地Ⅱ和样地Ⅲ叶脉密度与WUE的相关系数显著大于1(p<0.05)。旱柳植株通过合理调整叶脉密度与WUE间的资源配置,即增加叶脉密度的同时提高叶片的WUE,以补偿水分梯度上的不利因素对种群正常的生理活动带来的影响,反映了该物种在异质生境中具有较强的叶片性状可塑性,从而有利于其适应特殊的湿地生境。Aims The correlation between vein density and water use efficiency（WUE）affects the balance between water supply and demand of plant leaves,which is significant for comprehending the ecological adaptation strategies of plants.The objective of this study was to study how Salix matsudana modulated vein density and WUE along a soil moisture gradient in Zhangye Wetland,China.Methods The study was conducted in floodplain wetland near Heihe River in Zhangye City,Gansu Province,China.Three sample plots,at a spatial interval of 70 m,were set up along a soil moisture gradient ordinally from the area near the water body to the wetland edge,plot Ⅰ（69.23%）,spot Ⅱ（48.38%）and spot Ⅲ（35.27%）.Community traits were investigated by using diagonal method,and all individuals of S.matsudana were used for measurements of height and canopy.At each plot,5 individuals of S.matsudana at 4 vertices and diagonal intersection were selected for measurements of vein density,WUE,net photosynthetic rate Important findings With decreasing soil moisture,the height,canopy,specific leaf area,Gs and Ci of S.matsudana decreased gradually,while the vein density,WUE,Pn,Tr,PAR and VPD increased gradually.The correlation between vein density and WUE was positive in all the three plots,but the relationship varied along the soil moisture plots gradient.There was a highly significant positive correlation（p0.01）between the vein density and WUE at plot Ⅰ and Ⅲ,whereas the correlation only reached a significant level（p0.05）at plot Ⅱ;The correlation coefficient between vein density and WUE is significantly smaller than 1 at plot Ⅰ（p0.05）,while the correlation coefficient is significant greater than 1 at plot Ⅱ and Ⅲ（p0.05）.We can conclude that varied relationships between vein density and WUE of S.matsudana along a soil moisture gradient could reflect plant acclimation.

关 键 词：旱柳 叶脉密度 水分利用效率 关联性 土壤水分梯度 张掖湿地 

分 类 号：Q948[生物学—植物学]