不同退化程度高寒嵩草草甸基况的初步研究

Preliminary study on range conditions of alpine Kobresia meadows under different degradation degrees

以高寒嵩草草甸退化群落指标为依据,研究了青海省未退化、轻度退化、中度退化和重度退化阶段,高寒嵩草草甸植物群落的结构特征及土壤特性的差异性。结果表明:不同退化程度的高寒嵩草草甸,其地上、地下生物量,牧草高度,生草层厚度,裸斑面积,物种数,土壤含水量等呈显著差异。同未退化阶段相比,重度退化阶段的优良牧草生物量和地下生物量分别降低了43.2和10.1 g/m2。而重度退化阶段时,裸斑面积则达到最大值65 m2,土壤含水量则为最小值22.83%,鼠洞密度则随着高寒嵩草草甸退化程度的加剧,呈倒"V"变化趋势。分析表明,高寒嵩草草甸退化的结果是,由莎草科和禾本科为主的植物演替为杂类草地。

The range conditions of alpine Kobresia meadows under different degradation degrees（non-degraded,light degraded,moderate degraded and heavy degraded） were studied.The results showed that aboveground and underground biomass,height of vegetation community,depth of sod,area of bare ground,number of plant species and soil moisture had significant difference with the degraded alpine Kobresia meadow.The aboveground biomass and belowground biomass decreased by 43.2 and 10.1 g/m2 respectively in the heavy degradation stage,and the largest value of bare ground proportion was 65 m2 and the lowest soil moisture was 22.83%.The rodent burrow density showed a ＂V＂ pattern along with the degradation degrees.The dominant plant in community was changed from sedge and gramineous to forbs.