短期增温对川西北高寒草甸植物群落结构和叶片性状的影响

Effects of Short-trem Experimental Warming on Community Structure and Leaf Traits of Alpine Meadow in Northwest Sichuan

为探究高寒草甸群落和常见植物对气候变暖的响应,本研究以川西北高寒草甸植物群落及垂穗披碱草(Elymus nutans Griseb.)、四川嵩草(Kobresia setschwanensis Hand.-Mazz.)、无脉薹草(Carex enervis C.A.Mey.)、蒲公英(Taraxacum mongolicum Hand.-Mazz.)、蓝玉簪龙胆(Gentiana veitchiorum Hemsl.)、小花草玉梅(Anemone rivularis Buch.-Ham.var.flore-minore Maxim.)和鹅绒委陵菜(Potentilla anserina L.)7个常见物种为研究对象,研究短期增温对高寒草甸群落结构和常见植物的叶片性状的影响。结果表明:增温降低了植被群落丰富度指数(P<0.05),但未显著改变其群落高度、盖度、多样性指数和均匀度指数。增温显著增加了禾本科植物的盖度和重要值。增温后植物的叶宽、叶长、叶周长和比叶面积总体呈增加趋势,叶磷含量呈降低趋势,叶氮含量和氮磷比对增温的响应则因物种而异,表明高寒草甸植物对短期增温表现出了不同的适应策略。

To expore the responses of community structure and leaf traits to global climate warming,an experimental study was conducted between the warming and control treatments in a typical alpine meadow in northwestern Sichuan.Seven common species,Elymus nutans,Kobresia setchwanensis,Carex enervis,Taraxacum mongolicum,Gentiana veitchiorum,Anemone rivularis,Potentilla anserina,were further chosen to analyze the responses of leaf traits to experimental warming.The results showed that warming decreased species richness index,but significantly increased community height,vegetation cover,plant diversity index and species evenness index of the alpine meadow.Nevertheless,warming significant increased cover and relative important value of the grasses functional group.Experimental warming had a trend to increase leaf length,leaf width,leaf perimeter and specific leaf area,but had no significant effects on the leaf aspect ratio.Our results further indicated that warming tended to decrease leaf phosphorus.The responses of leaf nitrogen content and leaf nitrogen phosphorus ratio varied greatly with species,showing distinct adaptive strategies to short-term warming for different plants in the alpine meadows.