退化草地瑞香狼毒对小尺度群落组成及土壤理化性质的影响  

Effects of Stellera chamaejasme on small-scale community composition and soil physical and chemical properties in degraded grassland

作　　者：崔雪 潘瑶 王亚楠 郑小娜 高莹 CUI Xue;PAN Yao;WANG Ya-nan;ZHENG Xiao-na;GAO Ying(College of Life Sciences,Northeast Normal University,Changchun 130024,China)

机构地区：[1]东北师范大学生命科学学院,长春130024

出　　处：《生态学杂志》2020年第8期2581-2592,共12页Chinese Journal of Ecology

基　　金：国家自然科学基金(31570452);吉林省科技厅自然科学基金(20180101347JC);吉林省教育厅科学研究规划项目(JJKH20190263KJ)资助。

摘　　要：过度放牧导致草原生态系统呈现明显的退化趋势,草原优良牧草减少,逐渐转变成以有毒植物为优势种的退化草原。作为草地退化的指示种,有毒植物对邻近植物及土壤环境的影响一直是生态学研究的重要科学问题之一。为了更好地探究有毒植物在退化草地生态系统恢复过程中的影响,本研究以海拉尔自然保护区内封育恢复中的羊草草原为研究对象,依据群落中瑞香狼毒(Stellera chamaejasme)枝条数将植物群落划分为3个水平:高密度瑞香狼毒植物群落、低密度瑞香狼毒植物群落、无瑞香狼毒植物群落,调查群落物种组成并测定了土壤理化指标。结果显示:(1)高密度瑞香狼毒小尺度范围内改变了群落物种组成,提高Shannon指数和Patrick指数,说明在退化草地恢复过程中瑞香狼毒的存在能够改变群落物种丰富度进而改变其物种多样性。(2)随着瑞香狼毒密度的增加,部分禾本科植物与瑞香狼毒的联结性质也发生了变化。早熟禾(Poa annua)、贝加尔针茅(Stipa baicalensis)与瑞香狼毒的联结性质由正联结变为负联结;洽草(Koeleria litvinowii)由无联结变为负联结;羊草(Leymus chinensis)、糙隐子草(Cleistogenes squarrosa)、羽茅(Achnatherum sibiricum)未发生改变。(3)瑞香狼毒能够改变群落中各科相对重要性。随着瑞香狼毒密度增加,豆科、蔷薇科重要值增大,菊科重要值降低,禾本科无明显变化。(4)瑞香狼毒对土壤全氮、pH有一定的影响。其中,低密度瑞香狼毒群落的土壤全氮含量显著高于其他两组,其土壤pH也显著高于无瑞香狼毒存在的对照组。土壤全碳、速效态的氮和磷在不同密度瑞香狼毒群落之间无明显差异。土壤理化性质小尺度的变化可能是推动退化草地植物恢复的基础。Overgrazing has resulted in degradation of grassland ecosystems,with the consequences of decreased dominance of foraging grasses and increased dominance of some poisonous species.As an indicator of grassland degradation,the impacts of poisonous species on adjacent plant species and soil environment are one of the important scientific issues in ecological research.To better explore the impacts of poisonous species in the restoration process of degraded grassland ecosystem,we selected the fenced and restored Leymus chinensis grasslands in Hailaer nature reserve as the research object.According to branch number of S.chamaejasme(a poisonous plant)per unit area,plant communities were classified into three types:community with highdensity,low-density,and without S.chamaejasme,to investigate community species composition and soil physicochemical characteristics.The results showed that:(1)High density of S.chamaejasme altered plant community composition at small spatial scale by increasing Shannon index and Patrick index,which indicated the significant effects of S.chamaejasme on species richness.(2)With increasing S.chamaejasme density,the association properties of some Gramineae species and S.chamaejasme were changed.The association properties of Poa annua,Stipa baikalensis and S.chamaejasme were changed from positive to negative,while that of Koeleria litvinowii and S.chamaejasme was changed from no association to negative.The associations among Leymus chinensis,Cleistogenes squarrosa,Achnatherum sibiricum and S.chamaejasme were unchanged.(3)S.chamaejasme could alter the relative importance of plant families in the community.Increased S.chamaejasme dominance enhanced the importance value of Leguminosae and Rosaceae,but decreased that of Compositae.There was no obvious change of Gramineae in importance value.(4)The presence of S.chamaejasme affected soil total nitrogen and p H.The community with low-density S.chamaejasme had significantly higher soil total nitrogen content than the other two groups.It also had signific

关 键 词：瑞香狼毒 多样性指数 种间联结 土壤养分 

分 类 号：S812.2[农业科学—草业科学]