祁连山东段高原鼢鼠栖息地植物群落物种分布与土壤因子的关系

Relation between plant community speciesdistribution and soil factors in plateau zokor habitatin alpine meadow, the eastern Qilian Mountains

摘要:

【目的】 研究高原鼢鼠栖息地植物群落组成变化，以及植物群落物种分布与土壤理化性质关系。【方法】 以祁连山东段高原鼢鼠（Eospalax baileyi） 栖息的高寒草甸为对象，设置4 个不同高原鼢鼠鼠丘密度干扰区，调查植物群落特征和土壤理化性质，应用多元排序分析方法。【结果】 高原鼢鼠干扰造成栖息地植物物种丰富度变异不显著，但是增加了特有物种和总的物种数量。高原鼢鼠干扰降低了优势种矮生嵩草（ Kobresia humilis）的重要值，各干扰强度样地重要值累积对数模型拟合曲线达到显著水平（R2＞0. 95，P＜0. 01）；随干扰强度增加，植物群落重要值整体下降。同时，高原鼢鼠干扰显著增加了杂类草植物在群落中占比（F=4. 30，P＜0. 05）。冗余分析结果表明，土壤因子分别解释物种和功能类群空间分布变异的22. 6% 和54. 8%（P＜0. 05），土壤温度、全氮和水分对群落物种分布的贡献率最高，分别占总解释效应21. 28%、18. 31% 和16. 25%。【结论】 极重度高原鼢鼠干扰明显改变植物群落结构，鼢鼠干扰下土壤水热条件驱动高寒草甸植物物种的空间分布格局。

Abstract:

【Objective】 The study was carried out to explore the changes of plant community components underthe plateau zokor （Eospalax baileyi） disturbances and the relation between species distribution of plant communityand soil factors under these disturbances.【Method】 The plateau zokor living in the alpine meadow was selected asthe research subject. Four disturbance plots with different plateau zokor mound densities were set up to investigateplant community characteristics and physical and chemical properties of soil. The multivariate ordination analysismethod was used in the study.【Result】 The results indicated that the disturbances caused by the zokor did not changethe richness of plants species in the zokor’s habitat（F=1. 20，P＞0. 05），while increased the both number of totalplant species and the specialized plant species. The zokor’s disturbances reduced the important value of the dominantspecies（ Kobresia humilis），The fitting curve of cumulative logarithmic model of the important value reached a signifi-cant level at each plot with different disturbance intensity （R2＞0. 95，P＜0. 01）. The value of plant community de-creased along with the disturbance intensity increasing. Moreover， the zokor’s disturbance significantly increased theproportion of miscellaneous grass plants in the plant community（F=4. 30，P＜0. 05）. The results of redundancyanalysis showed that the factors in term of soil explained 22. 6% and 54. 8% of the variation of species and functionalgroups at the spatial distribution， respectively （P＜0. 05），while soil temperature， total nitrogen and soil moisturehad the greatest contribution （accounting for 21. 28% and 18. 31% and 16. 25% of the total explained effect，respec-tively） for the species distribution of plant community.【Conclusion】 Extremely severe disturbance by plateau zokorssignificantly changed the plant community structure. The spatial distribution pattern of plant species in alpine meadowwas driven by soil water and heat conditions under zokor disturbance.