不同海拔高寒草甸土壤微量元素含量及其与植被的关系

Content of Soil Trace Elements in Alpine Meadows at Different Altitudes and Relationships with Vegetation

为了探究高寒草甸微量元素随海拔的分布特征及其与植被的关系。本研究以东祁连山高寒草甸为研究对象,调查并测定了不同海拔下高寒草甸植被群落和土壤微量元素含量,采用冗余分析(Redundancy analysis,RDA)分析土壤微量元素与植被群落的关系。结果表明,高寒草甸植被总盖度、草层盖度、地上生物量、莎草科、豆科和杂类草地上生物量均随海拔的升高呈先升高后降低的趋势,在3200 m处达最大值,禾本科地上生物量随海拔升高依次降低;土壤钙(Ca)、铁(Fe)、铜(Cu)和锰(Mn)含量随海拔的升高呈先降低后升高的趋势,土壤镁(Mg)、锌(Zn)和钼(Mo)含量随海拔的升高呈先升高后降低的趋势,土壤钴(Co)含量随海拔的升高依次降低,土壤硒(Se)含量随海拔的升高呈波动性上升;相关性分析和RDA分析表明,土壤微量元素Mo和Fe含量显著影响着高寒草甸植被的生长。综上所述,海拔显著影响着高寒草甸土壤微量元素的分布,高寒草甸土壤管理过程中应该关注微量元素Mo和Fe,建议将微量元素Mo和Fe作为高寒草甸土壤健康评价指标。

The aim of this study was to explore the distribution characteristics of trace elements with altitude in alpine meadows and the relationship with vegetation community.In this study,the alpine meadow in the Eastern Qilian Mountains was the research object.The vegetation community and soil trace element content of the alpine meadow at different altitudes were investigated and measured,and(Redundancy analysis,RDA)was used to analyze the relationship between soil trace elements and vegetation community.The results of the study showed that,with the increase in altitude,the total vegetation coverage,grass coverage,above-ground biomass,Cyperaceae,Leguminous,and weeds above-ground biomass of alpine meadows all increased first and then decreased and the maximum value was 3200 m.With the decrease of the aboveground biomass of the gramineous family,the content of soil Ca,Fe,Cu,and Mn first decreased and then increased and the content of soil Mg,Zn and Mo first increased and then decreased.And the soil Co content decreases and the soil Se content rise volatically with the increase in altitude.Correlation analysis and RDA analysis showed that soil trace elements Mo and Fe significantly affected the growth of alpine meadow vegetation.In conclusion,altitude significantly affects the distribution of soil trace elements in alpine meadows.The trace elements Mo and Fe should be paid attention to in the process of soil management of alpine meadows,and it is suggested to use the trace elements Mo and Fe as indicators for evaluating the soil health of alpine meadows.