摘要
以科尔沁沙地4种不同退化程度沙地群落为研究对象,采用野外植物样方调查与室内土壤理化分析相结合的方法,系统分析了固定沙地(潜在沙漠化阶段)、半固定沙地(轻度沙漠化阶段)、半流动沙地(中度沙漠化阶段)和流动沙地(严重沙漠化阶段)4个群落的植被、土壤特征的变化以及土壤与植被之间的相互关系,为退化沙质草地群落地恢复与重建提供科学依据。结果表明,(1)草地沙漠化过程中,群落物种组成发生显著变化,物种数不断减少,从20下降到11。不同群落盖度(F=42.569,n=120,P<0.001)、密度(F=38.817,n=120,P<0.001)和地上生物量(F=29.017,n=120,P<0.001)均存在显著差异,且下降趋势明显,下降幅度分别为82%、78%和85%。(2)草地沙漠化过程中,草本植物占据绝对优势,但其比例明显下降,多年生草本植物和灌木的物种数总体呈下降趋势。藜科植物具有广适性,数量相对稳定,重要值呈现上升趋势;禾本科和豆科植物种类和重要值都呈大幅下降趋势。菊科植物相对较少,从半固定沙地到流动沙地,差巴嘎蒿(Artemisia halodendron)在群落中占有重要地位。(3)草地沙漠化过程中,Shannon-Wiener指数、Simpson指数、均匀度指数和Margalef指数均呈下降态势。(4)草地沙漠化过程中,土壤机械组成从固定沙地到流动沙地,粗砂含量增加,细砂粒、黏粉粒含量呈下降态势,土壤水分也不断减少。土壤养分全磷、全氮、速效磷、速效氮和有机质的含量随着沙漠化程度的加剧,表现出不同程度的降低,且差异显著(P<0.05)。(5)草地沙漠化过程中,土壤与植被间呈现出显著的相关性(P<0.05),说明土壤与植被紧密联系在一起,沙漠化过程实质就是土壤与植被协同退化的结果。
To better recover and reestablish the degraded sandy communities,relationship between the soil and plant communities were studied on4different degraded sandy communities that are fixed sand land(potential desertification stage),semi-fixed sand land(light desertification stage),semi-shifting sand land(medium desertification stage)and shifting sand land(heavy desertification stage)in Horqin sandy land.The results shown that during grassland desertification process:(1)The species quantity declined significantly from20to11Moreover,there was a significant difference among the aboveground biomass s(F=29.107,w=360,P<0.001),the coverage(F=42.569,n=120,P<0.001)and the density(F=38.817,n=120,P<0.001),meanwhile,the ground biomass and coverage reduced gradually,the decrease rage were82%,78%and85%respectively.(2)Herbaceous plants are the domain species,while its ratio was obviously decreased.Moreover,the species quantity of perennial herbs and shrubs were declined.Chenopodiaceae had a wide adaptability which kept at relatively stable level and its important value was increased gradually.Gramineae and Legume were experienced a sharp decrease,meanwhile,there was a relatively small number of Compositae which were migrate from semi-fixed to shifting sand land.(3)Shannon-Wiener index,Simpson index,evenness index and Margalef index suggested a decreasing trend.(4)The physical and chemical properties of the soil also degraded.Moreover,there were a significant reduction of total phosphorus,total nitrogen,available phosphorus,available nitrogen and organic matter content(P<0.05)along with the intensification of desertification.And(5)there was a significant correlation between the soil and vegetation(P<0.05)which indicates that the desertification process is the result of the synergetic degradation of soil and vegetation.
作者
熊炳桥
赵丽娅
张劲
李艳蔷
陈红兵
李锋瑞
XIONG Bingqiao;ZHAO Liya;ZHANG Jin;LI Yanqiang;CHEN Hongbing;LI Fengrui(School of Resources and Environmental Science, Hubei University,Wuhan,430062, China;Hubei Key Laboratory of Regional Development and Environmental Response, Hubei University,Wuhan,430062, China;Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China)
出处
《生态环境学报》
CSCD
北大核心
2017年第3期400-407,共8页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31070370)
湖北省教育厅重点项目(D2015003)
湖北省科技厅软科学专项(2013BDF034)
生物资源绿色转化湖北省协同创新中心项目
关键词
沙漠化
群落特征
土壤机械组成
土壤养分
相互关系
desertification
community characteristics
soil mechanical composition
soil nutrient
relationship
