高寒草甸退化对鹅绒委陵菜克隆生长特征的影响

为了揭示高寒草甸典型匍匐茎克隆植物对不同生境的生态适应对策，验证生境适应假说，并为高寒草地的退化演替机理研究提供依据，以调查统计和比较样地法研究了江河源区高寒草甸退化对鹅绒委陵菜克隆生长特征的影响。研究表明，重度退化草甸的植物群落结构、功能以及土壤特征发生了明显的变化，继而对鹅绒委陵菜无性系的克隆生长行为和形态特性产生了影响。高寒草甸退化后鹅绒委陵菜的匍匐茎增多，分支强度加大。退化草甸内鹅绒委陵菜的基株高度小于未退化草甸，根长大于未退化草甸，基株的叶片数目问没有明显差别。退化草甸的分株高度显著小于未退化草甸，而分株叶数大于未退化草甸，根长小于未退化革甸且差异不显著。未退化草甸内鹅绒委陵菜无性系的问隔子长度、粗度和匍匐茎长度大于退化草甸，间隔子平均数目少于退化草甸，差异都不显著。随着鹅绒委陵菜无性系匍匐茎数目的增加，不论重度退化草甸与未退化草甸，用于鹅绒委陵菜克隆繁殖的能量投资也逐渐增加。鹅绒委陵菜在未退化草甸用于克隆繁殖的能量投资比例高于退化草甸，其中未退化草甸内鹅绒委陵菜基株的干重占无性系总生物量的比例略低于退化草甸，分株和匍匐茎的干重占无性系总生物量的比例高于退化草甸。高寒草甸退化对鹅绒委陵菜克隆生长特征的这些影响，与植物群落结构和功能的变化导致生境变异密切相关，是其对高寒草甸退化导致的资源和生境差异的反应，也是对资源利用达到的最合理状态，是一种选择适应的结果，有利于克隆繁殖潜力的发挥。同时为生境适应假说提供了又一例证。

Alpine meadow degradation alter the clonal growing characteristics of Potentilla anserina

The method of field survey and comparative sampling plots was employed to investigate the ecological adapting strategies of the typical stolon plant in different habitats and the influences of alpine meadow degradation to the clonal growing characteristics of Potentilla anserina. The purpose of this study also include that examine the hypothesis of habitat adaptation and provide the process of the degrading mechanism in alpine meadow. The experiment sets was located in the headwaters of the Yangtze, Yellow rivers. The results suggested that the obvious change of plant community structure and function, soil properties influenced the clonal growing behavior and morphological characteristics of P. anserina in heavily degraded meadow. The stolon number and the branching intensity of P. anserina were increased at the degraded alpine meadow. The genet and ramet of P. anserina at the non-degraded alpine meadow were higher than those at the degraded alpine meadow. The genet root of P. anserina at the degraded alpine meadow was deep than that at the non-degraded alpine meadow. There was no significant difference of genet leaf number at the two sampling plots. The ramet root of P. anserina at the degraded alpine meadow was shorter than that at the non-degraded alpine meadow. The ramet leaf number at the degraded alpine meadow was more than that at the non-degraded alpine meadow significantly. The spacer length, spacer thickness and stolon length of P. anserina at the non-degraded alpine meadow were larger than those of P. anserina at the degraded alpine meadow. The average spacer number of P. anserina at the non-degraded alpine meadow was less than that of P. anserina at the degraded alpine meadow. With the increase of stolon number of P. anserina clone, the energy allocation of P. anserina for the clonal reproduction were increased slowly at the two sampling plots. The energy allocation of P. anserina for the clonal reproduction at the non-degraded alpine meadow was more than that at the degraded alpine meadow. The dry mass proportion of the genet to the total biomass of the clone at the non-degraded alpine meadow was slightly less than that at the degraded alpine meadow. The proportions of the ramet and the stolon biomass to the total biomass of the P. anserina clone at the non-degraded alpine meadow were larger than that at the degraded alpine meadow. The influences of alpine meadow degradation on the clonal growing characteristics of Potentilla anserina was closely correlated to the habitat change which was caused by the change of plant community structure and functions. All the influences mentioned above were the responses of P. anserina to the resource and habitat variation, were the most reasonable situation to the resource utilization and the results of adaptation as well. The influence was also benefit to exert the potency of clonal reproduction of P. anserina. The research result proved the evidence of the hypothesis of habitat adaptation.