摘要
洪湖湖滨带是洪湖湿地的重要组成部分,具有涵养水源、保持水土、截污缓冲、维持生物多样性的功能。为了解洪湖湖滨带植被现状及变化过程,进行了洪湖湖滨带植被调查,结合土地利用实地勘察和卫片分析,结果显示空心莲子草、马唐、狗尾草、葎草、小飞蓬、菰、莲、芦苇、凤眼莲和浮萍综合优势比高,是洪湖湖滨带优势种。物种数较20世纪60年代明显减少。其中入侵种空心莲子草和凤眼莲在各样地出现的频率很高。以全部植物种计算,湖滨带植被Shannon-Weaver指数在1.50~2.98之间,Simpson指数在0.7~0.9之间,但以水生植物种计算,多样性明显降低,其Shannon-Weaver指数处在0.69~2.29之间,大多数均小于2,Simpson指数在0.50~0.89范围变动。根据卫片分析,2011年湖滨带水位变幅区面积为62.72km2,与60年代相比缩减71.4%,实地勘察证实洪湖原有湖滨带大部分已被开发成鱼塘和居住地。综合调查结果和历时资料表明,洪湖湖滨带植物种类减少,多样性降低,生态功能显著降低。
As the important part of Honghu lake,the littoral zone plays important roles in water and soil conservation,pollutant degradation,and biodiversity conservation.In order to reveal the current status and the historical change of the lake reparian vegetation,vegetation and land utilization survey in lake Honghu was conducted in September 2012 and June 2014.At the same time,relevant satellite images were analysed to calculate the area of reparian zone.It was found that plant species including Alternanthera philoxeroides,Digilaria sanguinalis,Setaria viridis,Humulus scandens,Conyza canadensis,Zizania latifolia,Nelumbo nucifera,Phragmites communis,Eichhornia crassipes,Lemna minor were the dominant species with high summed dominance ratio(SDR).Total plant species decreased significantly comparing to those in the sixties of last century.Invasive species,Alternanthera philoxeroides and Eichhornia crassipes,showed high frequencies in the reparian zone.The Shannon-Weaver index ranged from 1.50 to 2.98 and 0.7to 0.9for Simpson index when all species counted.That decerased when only aquatic plants(emergent,floating and submerged plants)were counted,the Shannon-Weaver index and Simpson index ranged from 0.69 to 2.29 and 0.50 to 0.89 respectively,most of sites' Shannon-Weaver index lower than 2,and had stronger fluctuation.According to the analysis of TM satellite images,the area of the littoral zone in 2011 was 62.72km2 decreased by 71.4%compared with that in the sixties of last century.Most part in the littoral zone has been used as fishery pond and construction land by siteinvestigation.The investigation results and historical change demonstrated that the plant species and biodiversity decreased,and the ecological functions of Honghu Lake littoral zone was impaired significantly.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2015年第S1期38-45,共8页
Resources and Environment in the Yangtze Basin
基金
国家试点湖泊生态环境保护项目洪湖专题国家重大科技专项(2013ZX07104-004
2013ZX07105-005)
国家自然科学基金项目(31200399)
关键词
洪湖
湖滨带
植被
退化
Lake Honghu
littoral zone
vegetation
degradation
