高原鼢鼠扰动对鹅绒委陵菜无性系特征的影响

Effects of disturbance of plateau zokor on asexual reproduction characteristics of Potentilla anserina

摘要:

【目的】明确草地退化背景下高原鼢鼠(Eospalax baileyi)种群密度的增多对草地退化进程的影响，为高寒草甸的退化演替提供证据，并为草地生态系统的恢复提供理论依据。【方法】以草地退化过程中优势种鹅绒委陵菜(Potentilla anserina)为研究对象，探究高原鼢鼠扰动对其无性系种群特征的影响。【结果】随着高原鼢鼠扰动增加，植被群落物种总数、物种丰富度、香农维纳指数和辛普森指数均降低，植物优势种由矮嵩草、苔草变为垂穗披碱草、冰草再到鹅绒委陵菜、车前等杂类草；鹅绒委陵菜地上、地下生物量亦呈减小趋势，根冠比则先减小后增大；中密度扰动下的鹅绒委陵菜盖度、重要值和株高均最大；鹅绒委陵菜在高原鼢鼠低密度区无匍匐茎，在中密度区其匍匐茎长度、间隔子数目及长度均大于高密度区。【结论】鹅绒委陵菜通过匍匐茎特有的调节策略来克服高原鼢鼠扰动所造成的不利外界环境的影响，最终达到有效繁殖的目的。

Abstract:

【Objective】 The increase in population density of plateau zokor (Eospalax baileyi) under the back‐ ground of grassland degradation has accelerated the process of grassland degradation，but there are few empirical stud‐ ies on it.【Method】 This study took Potentilla anserina，the dominant species in the process of grassland degradation， as the research object，and explored the influence of plateau zokor disturbance on the characteristics of clone popula‐ tions.【Result】 The results showed that as the plateau zokor disturbance increased，the total number of species in the vegetation community，species richness，Shannon Wiener Index and Simpson Index were all reduced. At the same time，the dominant plant species changed from kobresia Kobresia humilis and Carex giraldiana to Elymus nutans， Agropyron cristatum，and then to the miscellaneous grass such as Potentilla anserina and Plantago asiatica. The above ‐ground and underground biomass of Potentilla chinensis also showed a decreasing trend，and the root‐to‐shoot ratio first decreased and then increased. The coverage，importance value and plant height of Potentilla goose down under the disturbance of medium density were the largest. Potentilla edulis had no stolon in the low-density area of plateau zokor，and its stolon length，number of spacers and length in the medium-density area were larger than those in the high‐density area.【Conclusion】 In conclusion，Potentilla edulis overcomes the influence of the unfavorable external environment caused by the disturbance of the plateau zokor through the unique regulation strategy of the stolon，and fi‐ nally achieves the purpose of effective reproduction.