三峡水库消落区植物群落结构及其季节性变化规律  

Plant Community Structure and Seasonal Variation in the Water Level Fluctuation Zone of Three Gorges Reservoir

作　　者：张志永[1] 胡晓红 向林 邹曦[1] 史方[1] 李怡 胡莲[1] ZHANG Zhi-yong;HU Xiao-hong;XIANG Lin;ZOU Xi;SHI Fang;LI Yi;HU Lian(Key Laboratory of Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem of Ministry of Water Resources,Institute of Hydroecology,Ministry of Water Resources and Chinese Academy of Sciences,Wuhan 430079,P.R.China;River and Lake Protection and Construction Safety Center Changjiang Water Resources Commission,Wuhan 430010,P.R.China;College of Horticulture and Forestry Science of Huazhong Agricultural University,Wuhan 430070,P.R.China)

机构地区：[1]水利部中国科学院水工程生态研究所,水利部水工程生态效应与生态修复重点实验室,湖北武汉430079 [2]长江水利委员会河湖保护与建安中心,湖北武汉430010 [3]华中农业大学园艺林学学院,湖北武汉430070

出　　处：《水生态学杂志》2020年第6期37-45,共9页Journal of Hydroecology

基　　金：国家重大研发计划(2016YFC0502208);国家自然科学基金面上项目(51679154);重庆市技术创新与应用示范项目(cstc2018jszx-zdyfxmX0021)。

摘　　要：为探究三峡水库消落区出露期间植物群落结构的季节性变化规律,于2017年4、6和8月,设置了15个调查样地,根据高程将消落区分为145~155 m、155~165 m和165~175 m共3个区域,并设置未水淹区域(高程175~185 m)为对照。结果表明,消落区出露时间显著影响植物群落组成,随着出露时间的延长,群落优势种及其优势度变化规律因植物的生活型不同呈现出相反的变化规律。从4月至8月,优势植物狗牙根、牛鞭草、喜旱莲子草等多年生草本植物优势度下降,鬼针草、苍耳、醴肠、水蓼、野胡萝卜、狗尾草等一年生草本植物优势度增加;而未水淹区植物优势种及其优势度变化不会因生活型不同而表现出不同的规律,不同采样地点的植物群落优势种差异较大,相对来说艾蒿较为优势,其次为小飞蓬。高程也是影响植物群落特征的主要因子,植物群落Shannon-Wiener指数、Margalef指数、Simpson指数、植物高度均值显著低于未水淹区域;随着高程的增加,生物多样性指数及植物高度均值呈增加趋势。植物内在的适应机制,包括植物本身的冬季耐水淹能力、夏季抗旱能力、抗病虫害能力及其繁殖对策、种源扩散对策等是影响植物群落分布的主因;而外界环境条件,包括消落区土层厚度、地形坡度、土壤基质氮磷等营养盐以及受水淹持续时间、水淹深度、高程、消落区出露时间等是其主要驱动因子。The ecological problems in the water level fluctuation zone(WLFZ)of Three George Reservoir have attracted much attention in relevant departments of both the national and local government.As of 2017,the vegetation in the WLFZ had undergone eight wet-dry cycles.The objectives of this study were to characterize seasonal variation of the WLFZ plant community and to analyze the internal adaptive mecha-nisms and external environmental factors affecting plant growth.Our study will provide data to support ec-ological restoration and advance the WLFZ theory of large-scale reservoirs.In April,June and August 2017,samples were collected from a total of 174plots from 15sites along three WLFZ elevation gradients(145-155m,155-165m,165-175m),and within an un-flooded area(175-185m),set as the control.The height,coverage and the above ground biomass of the plants were measured in situ.Results show that the dominant species and their dominance in the plant community presented different rules with increased ex-posure time and were closely related to the different plant life forms.From April to August,dominance by perennial herbs(Cynodon dactylon,Hemarthria altissima and Alternanthera philoxeroides)decreased,while dominance by annual herbs(Bidens pilosa,Xanthium sibiricum,Eclipta prostrata,Polygonum hydropiper,Daucus carota and Setaria viridis)increased.The dominant species composition and their plant community dominance in the un-flooded area did not display any relation with plant life form.The dominant species of plant community in the un-flooded area was obvious different among the different sam-pling sites,with relative higher dominance by Artemisia argyi and Comnyza canadensis.Elevation was al-so a major factor affecting plant community characteristics.The mean value of Shannon Wiener diversity index,Margalef richness index,Simpson index and plant height of the WLFZ plant community increased with elevation and were significantly lower than those in the un-flooded area.The primary internal adapta-tion mechanisms of WLFZ plants

关 键 词：三峡水库 消落区 植物群落 优势种 适应机制 

分 类 号：Q948[生物学—植物学]