摘要
植物叶片性状反映了植物对环境的高度适应能力及其在复杂生境下的自我调控能力。本研究以三峡库区典型支流消落带狗牙根(Cynodon dactylon)、苍耳(Xanthium sibiricum)、藿香蓟(Ageratum conyzoides)和喜旱莲子草(Alternanthera philoxeroides)四种主要物种为研究对象,通过测定叶片鲜重(leaf fresh weigh)、叶片干重(leaf dry mass)、叶面积(leaf area)、干物质含量(leaf dry material content,LDMC)和比叶面积(specific leaf area,SLA)等指标,采用标准化主轴估计的方法研究叶不同性状之间的关系。结果表明:苍耳、狗牙根和藿香蓟的叶鲜重在消落带分布的变异程度高;苍耳的叶干重和叶面积变异程度较高,狗牙根、藿香蓟和喜旱莲子草的叶干重和叶面积变异程度处于中等水平;四种植物的比叶面积和叶干物质含量变异程度都较低;随着海拔高程的升高,狗牙根和苍耳的SLA先缓慢降低后升高,藿香蓟的SLA缓慢上升,喜旱莲子草的SLA呈先上升后下降的趋势;狗牙根和藿香蓟的LDMC随海拔高程升高缓慢下降,苍耳的LDMC随海拔的升高先升高后下降,喜旱莲子草的LDMC随海拔的升高先降低后升高;狗牙根、喜旱莲子草和苍耳的叶面积和叶干物质量呈异速生长关系,狗牙根的叶干物质量增长速度低于叶面积增长速度,喜旱莲子草和苍耳的叶干物质量增长高于叶面积的增长,藿香蓟的叶面积和叶干物质量呈等速增长关系。这些研究结果表明,狗牙根作为消落带低高程的优势物种,通过干物质的投入生长出薄而大的叶片适应极端的环境。而高程的增加,伴随着水热条件的改善,喜旱莲子草和苍耳则趋向于通过大量干物质的累积生长出较小的叶片使光合利用效率最大化。藿香蓟作为155 m高程以上才出现的物种,仅通过叶干物的累积来抵抗水淹,叶面积和叶干物质量的增长接近等速生长。
The leaf functional traits of plant can reflect its adaptability to the environment and self-regulation in chaotic habitats.The present study explored the relationship among leaf traits of four main species in the hydro-fluctuation zone of the Three Gorges Reservoir,namely,Cynodon dactylon,Xanthium strumarium,Ageratum conyzoides and Alternanthera philoxeroides.Indices like leaf fresh weight,leaf dry weight,leaf area,leaf dry matter content(LDMC)and specific leaf area(SLA)were selected and Standardized major axis estimation(SMA)was used.The results show that the leaf fresh weight of C.dactylon,X.strumarium and A.conyzoides has a high variable coefficient values in the hydro-fluctuation zone.Leaf dry mass and leaf area of X.strumarium also have a high variable coefficient values,while those of C.dactylon,A.conyzoides and A.philoxeroides are at the middle level.The variability of SLA and LDMC of four species is small.With the elevation rise,the SLA of C.dactylon and X.strumarium decreases slowly and then increases,and the SLA of A.conyzoides increases slowly.The SLA of A.philoxeroides increases first and then decreases with the rise in elevation.The LDMC of C.dactylon and A.conyzoides decreases along with elevation rise,and the LDMC of X.strumarium increases first and then decrease.The LDMC of A.philoxeroides decreases first and then increases with the elevation rise.An allometric relationship between leaf area and leaf dry mass was found for C.dactylon,A.philoxeroides and X.strumarium.The growth rate of leaf dry mass for C.dactylon is lower than that of leaf area.The growth rate of leaf dry mass for A.philoxeroides and X.strumarium is higher than that of leaf area.An isometric relationships between leaf area and leaf dry mass was observed for A.conyzoides.Those results show that C.dactylon,as the dominant species at low elevation,grows thin and large leaves by the input of the dry mass to adapt to the extreme environments.The rise in elevation is accompanied by the improved hydrothermal conditions,X.strumarium and
作者
孙小祥
易雪梅
黄远洋
陈姗姗
马茂华
吴胜军
SUN Xiaoxiang;YI Xuemei;HUANG Yuanyang;CHEN Shanshan;MA Maohua;WU Shengjun(Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714,China;Key Laboratory of Reservoir Aquatic Environment,Chinese Academy of Sciences,Chongqing 400714,China;University of Chinese Academy of Sci-ences,Beijing 100049,China;School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《三峡生态环境监测》
2021年第4期1-10,共10页
Ecology and Environmental Monitoring of Three Gorges
基金
国家自然科学基金项目(51779241,51709250,41601042)。
关键词
消落带
叶片功能性状
三峡库区
性状分异
hydro-fluctuation zone
leaf functional trait
Three Gorges Reservoir
trait variation
