引种植物水桦与乡土植物桑树对三峡库区消落带水淹的响应  

Response of Introduced Plant Betula nigra and Native Plant Morus alba to Flooding in the Draw-down Zone in the Three Gorges Reservoir Area

作　　者：高岚[1] 刘芸[1] 熊兴政[1] 邬静淳 王萌[1] 袁贵琼 欧阳[1] 任立 Gao Lan;Liu Yun;Xiong Xingzheng;Wu Jingchun;Wang Meng;Yuan Guiqiong;Ou Yang;Ren Li(College of Resources and Environment,Southwest University Chongqing 400715;Xiushan County Wuling Mountain wetland plants Engineering Research and Development Center Chongqing 409902)

机构地区：[1]西南大学资源环境学院,重庆400716 [2]秀山县武陵山湿地植物工程技术研究开发中心,重庆409902

出　　处：《林业科学》2018年第9期147-156,共10页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(31370602)

摘　　要：【目的】对桑树与引种植物水桦在三峡库区消落带的生长及光合特性进行比较,探讨这2种木本植物对三峡库区消落带周期性水淹生境的适应性,为消落带植被重建适用树种选择提供理论依据。【方法】在重庆市万州区典型消落带170、175 m 2个高程的台地种植2年生桑树、水桦实生苗,之后自然生长,于每年4月上旬调查其存活率。供试种调查存活率后,于上述台地旁种植2年生桑树、水桦实生苗,2年后于4月上旬春季出露期、7月中旬夏季干旱期、9月底秋季淹水前期测定其生长量(株高、地径、冠幅)、光合特性(叶绿素、叶绿素荧光动力参数及气体交换参数)。【结果】170 m高程桑树、水桦的存活率显著低于175 m高程,而2个高程水桦存活率均大于桑树,其中170 m高程差异显著;170 m高程水桦的生长量均大于桑树,其中株高差异显著。春季出露期(SEP),170 m高程桑树叶片的叶绿素含量高于175 m高程,Pn、Gs、Tr、Ci、WUE无明显差异;夏季干旱期(SDP),桑树和水桦170 m高程叶绿素含量及Pn、Gs、Tr、Ci均大于175 m高程,其中桑树的Ci、Tr差异显著、水桦的Tr差异显著;秋季水淹前期(PFP),170 m高程水桦的叶绿素含量显著大于桑树,Pn、WUE与175 m高程无明显差异。SEP期,170 m高程桑树的qP、ETR、ΦPSⅡ大于175 m高程;PFP期,水桦在2个高程的ΦPSⅡ、ETR、qP基本与SDP期一致,170 m高程qN大于175 m高程。【结论】乡土树种桑树能通过出露后快速恢复叶片PSⅡ光反应系统的能力,提高光电子的传递速率,增加叶绿素含量而增强光合作用,积累更多有机物恢复生长来适应三峡库区冬季水淹的胁迫;引种植物水桦则通过延长光合作用时间,在桑树进入休眠期后仍保持较高的光能转化效率,积累更多的有机物以应对冬季水淹的过度消耗。桑树和水桦均能在一定程度上适应三峡库区消落带特殊的生境,引种植物水桦较本地树�【Objective】The growth and photosynthetic characteristics of the native Morus alba and the introduced plant Betula nigra planted in the Three Gorges Reservoir area were compared,and the adaptability of the two woody plants to the periodic flooded habitats of the Three Gorges reservoir zone was investigated to provide a scientific basis for the selection of suitable tree species for the vegetation restoration.【Method】In this study,two-year-old M.alba and B.nigra seedlings were planted on the tableland in typical draw-down zone at altitudes of 170 m and 175 m in Wanzhou,Chongqing.Then the seedlings grew naturally,and their survival rate was investigated in early April each year.After the preliminary experiment of testingsurvival rate,more two-year-old M.alba and B.nigra seedlings were planted on the side of the tableland.After two years,the growth(plant height,ground diameter,crown width)and photosynthetic characteristics(chlorophyll,fluorescence dynamic parameters,gas exchange parameters)were measured in Spring Exposure Period(SEP)of early April,Summer Drought Period(SDP)of mid-July and Pre-Autumn Flooding Period(PFP)at the end of September.【Result】The survival rate of M.alba and B.nigra at altitude 170 m was significantly lower than that at altitude 175 m.The survival rate of B.nigra was higher than M.alba at both altitudes,and the difference between the two species was significant at altitude 170 m.B.nigra grew faster than that of M.alba at altitude 170 m,and the height was significantly different.The chlorophyll content of M.alba at altitude 170 m was higher than that at altitude 175 m in SEP.There was no significant difference in P n,G s,Tr,C i and WUE between the two altitudes.In SDP,the chlorophyll content and P n,G s,Tr,C i of M.alba and B.nigra at altitude 170 m were higher than those at altitude 175 m.The differences in C i and Tr of M.alba were significant,and the difference in Tr of B.nigra was significant between the two altitudes.In PFP,the chlorophyll content of B.nigra at altitude 170

关 键 词：引种植物 水桦 三峡库区 光合参数 荧光动力参数 

分 类 号：S718.43[农业科学—林学]