Photosynthetic and water-related physiological characteristics of Periploca sepium in response to changing soil water conditions in a shell sand habitat  

作　　者：Xiao Wang Jiangbao Xia Ximei Zhao Mingming Dong Xianshuang Xing Ying Fang Qinqin Fu Zhaohua Lu 

机构地区：[1]Institute of Restoration Ecology,School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,People’s Republic of China [2]Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta,Binzhou University,Binzhou 256603,People’s Republic of China [3]Shandong Hydrology Center,Jinan 250013,People’s Republic of China

出　　处：《Journal of Forestry Research》2023年第2期453-467,共15页林业研究（英文版）

基　　金：supported by the Forestry Science and Technology Innovation Project of Shandong Province(No.2019LY006);the National Natural Science Foundation of China(No.31770761);Open Research Fund Program of Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta(Binzhou University)(No.2020KFJJ03);the Taishan Scholars Program of Shandong ProvincemChina(No.TSQN201909152)。

摘　　要：This study was performed to observe the effects of water on photosynthesis and water-related physiology in dominant shrubs in shell sand habitats.Four-year-old Periploca sepium seedlings were used as model species.A gradient of 12 water levels was established by artificially supplying the shell sand with water up to saturation and then allowing natural evapotranspiration to occur.The photo synthetic,chlorophyll fluorescence and stem sap flow parameters of P.sepium were measured under a range of water conditions.The different soil water conditions were classified according to the responses of these parameters.(1)With the increase in the relative water content(RWC)of the shell sand,the parameters of leaf photosynthesis,chlorophyll fluorescence and water-related physiology in P.sepium showed significant critical responses.The net photo synthetic rate(Pn),transpiration rate(Tr),instantaneous water use efficiency(WUE),potential water use efficiency(WUEi),maximum photochemical efficiency(Fv/Fm),actual photochemical efficiency(ΦPSII)and daily accumulation of stem sap flow all increased first and then decreased with increasing RWC,but the corresponding water conditions associated with their maximum values were not the same.An RWC of 69.40%was determined to be the optimal water condition for photosynthesis and water-related physiological activity in P.sepium.At an RWC of 36.61%,the mechanism of photosynthetic inhibition in P.sepium changed from stomatal limitation to nonstomatal limitation;this was also the minimum water requirement for maintaining normal photo synthetic processes.An RWC of 50.27%resulted in the highest WUE in P.sepium,indicating that moderate drought stress increased WUE.(2)Based on the quantitative relationship between the photo synthetic parameters of P.sepium and the shell sand water gradient,the soil water availability was classified into 6 water grades.The RWC range for maintaining strong photosynthesis and high WUE in P.sepium was 63.22-69.98%.(3)Gas exchange in P.sepium was inhibited under drough

关 键 词：Water gradient range Periploca sepium PHOTOSYNTHESIS Water physiology Water availability classifi cation Shell sand 

分 类 号：Q945.11[生物学—植物学]