巴音布鲁克高寒草地退化演替阶段植物群落特性研究

Alpine grassland community characteristics at the different stages of degenerating succession in Bayanbulak

以新疆天山南坡巴音布鲁克高寒草地为研究对象,通过主分量分析以及群落多样性指标,分析了不同退化演替阶段高寒草地植物群落特性变化规律。结果表明:以重要值为参数通过主分量分析(PCA)对样方进行排序,得到未退化、轻度退化、中度退化、重度退化4种类型群落;随着植物群落的逆行演替,优良牧草盖度、高度、频度等呈递减趋势,杂类草表现为增加趋势,植物群落物种多样性丧失。未退化阶段群落羊茅(Festuca ovina)、紫花针茅(Stipa purpurea)为优势种,随着退化加重,天山赖草(Leymus tianschanicus)、委陵菜(Ptentilla spp.)等在群落中占主导地位,地下芽根茎型草本植物逐渐代替地面芽密丛型禾草植物成为群落优势种。

The experiment conducted in Bayanbulak alpine grasslands on the southern slope of Tianshan Mountain showed the structural regulation of plants communities at different degraded level. The results indicated that according to the importance values which calculated from Principal Component Analysis（ PCA）,four kinds of populations：undeteriorated,mild - deteriorated,moderate - deteriorated and severe - deteriorated,respectively, were obtained and with the retrogressive succession of communities,the coverage,height and frequency of good pasture were decreased while the wild grasses were increased,so the diversity of communities declined. The dominant species of undegraded land were Festuca ovina and Stipa purpurea,but with the aggravation of grassland degradation,the wild grasses such as Leymus tianschanicus,Ptentilla spp. and so on played an important vole. At the same time,roots - type herbs gradually replaced the hemicryptophyte micronesia cong - type grasses and became dominant species.