【摘要】 为研究高寒生态系统植被群落对气候变化的响应,于2007年5月沿青藏高原东北祁连山南坡对海拔3 200m的嵩草草甸、3 400 m的灌丛草甸、3 600 m的杂草草甸和3 800 m的稀疏植被进行双向移栽试验。功能群(莎草类、禾本类、豆科类和杂类草)植被绝对盖度的方差分析表明高寒草甸植被群落对气候变化较为敏感。莎草类盖度与土壤含水量呈负线性相关,禾本类和豆科类分别与土壤含水量和气温呈正线性相关。海拔与杂类草盖度的二次方程可解释其61%的变异。非度量多维排序(non-metric multi-di mensional scaling,NMDS)暗示功能群对气候变化的响应具有特殊性。豆科类和杂类草、莎草类和禾本类存在较弱的盖度补偿效应。对比早期和模拟降温下的嵩草草甸群落组成,印证其具有较高的稳定性。更多还原

【Abstract】 For further understanding the response of alpine plant communities to climate change,we manipulated a reciprocal translocation experiment along the elevation gradients on the south slope of the Qilian Mountains,in the northeast Qinghai-Tibetan Plateau in May 2007.The translocated vegetation comprised 3 200 m of Kobresia meadow,3 400 m of shrub meadow,3 600 m of forbs meadow,and 3 800 m of sparse vegetation.Four functional groups(FG) were classified as sedge,graminoid,legume and forbs.An ANOVA of FG abundance showed that alpine plant communities were sensitive to climate change.Sedge cover correlated negatively and linearly with soil water content.Graminoid and legume abundance were linearly related to soil water content and temperature,respectively.The Quadratic equations between forbs and elevation accounted for 61% of variation.NMDS(non-metric multidimensional scaling) indicated that FG responded specially.There was a weak abundance compensation effect between legumes and forbs,sedges,and graminoids.The comparison between the plant community in Kobresia meadow under simulated cooling and historical survey,confirmed it was stable.更多还原