高原鼢鼠对若尔盖高原湿地草原土壤性质和植物生物量的扰动效应

Disturbing Effects of Plateau Zokor(Myospalax baileyi)on Soil Properties and Plant Biomass in Zoige Plateau Marshes

【目的】高原鼢鼠是若尔盖高原湿地最主要的鼠类之一,其扰动行为(采食和掘洞)会翻动土壤,改变土壤结构,破坏植物根系,从而影响土壤性质和植物生物量。本研究成果探讨了其影响机制,为维持生态平衡,促进生态文明建设,制定草地保护政策提供理论依据。【方法】2017年夏季采用刈割法和环刀法收集了该地区高原鼢鼠鼠丘、洞道上方、扰动样方、无扰动对照样方4类生境中的土壤含水率、土壤容重、植物地上生物量、植物地下生物量、植物生物量分配五类指标数据。【结果】不同生境类型样方中,土壤含水率表现为无扰动对照样方>洞道上方>扰动样方>鼠丘,无扰动对照样方、扰动样方、洞道上方3类生境之间差异不显著,鼠丘与以上3种生境类型间均表现为差异显著(P<0.05);土壤容重表现为扰动样方>无扰动对照样方>洞道上方>鼠丘,鼠丘生境显著低于扰动样方和对照样方,洞道上方生境显著低于扰动样方(P<0.05),其余两两之间差异不显著;植物地上生物量表现为扰动样方>无扰动对照样方>洞道上方>鼠丘,扰动样方和对照样方之间差异不显著,其余生境类型两两组合之间均差异显著(P<0.05);植物地下生物量表现为无扰动对照样方>扰动样方>洞道上方>鼠丘,所有生境类型两两组合之间均差异显著(P<0.05);地下生物量所占总生物量的比例均远大于地上生物量,生物量明显更多地分配到地下部分,且随着高原鼢鼠扰动,地下生物量所占比例呈现出逐步下降的趋势,地上生物量反之。【结论】高原鼢鼠扰动降低了土壤含水率、土壤容重、植物地上生物量和地下生物量,并使得植物生物量在高原鼢鼠扰动后增加了向地上分配的比例,对区域内生态系统功能产生深刻影响。

【Objective】Plateau Zokor is one of the most important rodents in Zoige Plateau Marshes.Its disturbance behavior(feeding and digging holes)will turn over the soil,change the soil structure,destroy the plant root system,thus affecting the soil properties and plant biomass.The results of this study explored its impact mechanism to provide theoretical basis for maintaining ecological balance,promoting the construction of ecological civilization and formulating grassland protection policies.【Method】In summer of 2017,five indicators of soil moisture content,soil bulk density,aboveground biomass,underground biomass and biomass allocation of plants were collected by mowing method and ring knife method in four habitats of Plateau Zokor mound,above the hole,disturbed quadrat and undisturbed control quadrat.The disturbance of Plateau Zokor decreases soil moisture content,soil bulk density,plant aboveground biomass and underground biomass,and increases the proportion of plant biomass allocated to the aboveground after the disturbance of Plateau zokor,which has a profound impact on the function of ecosystem in the region.【Result】In the sample plot of different habitat types,the soil moisture content exhibited as undisturbed control quadrat>above the hole>disturbed quadrat>mouse mound.There was no significant difference in soil water content among the three habitats of undisturbed control quadrat,disturbed quadrat and above the hole.There were significant differences between soil moisture content of the above three habitat types and mouse mound(P<0.05);The soil bulk density exhibited as disturbed quadrat>undisturbed control quadrat>above the hole>mouse mound.The soil bulk density of mouse mound habitat was significantly lower than that of disturbed quadrat and undisturbed control quadrat.The soil bulk density of the habitat above the hole was significantly lower than that of the disturbed quadrat(P<0.05).The difference between other habitats was not significant;The aboveground biomass exhibited as disturbed quadrat>undisturbed control quadrat>above the hole>mouse mound.There was no significant difference in aboveground biomass between disturbed quadrat and undisturbed control quadrat.The differences among the other habitat types were significant(P<0.05);The underground biomass exhibited as undisturbed control quadrat>above the hole>disturbed quadrat>mouse mound.The differentiation between two types of habitat were significant(P<0.05);The ratio of the underground biomass in all vegetation biomass is way over than the aboveground biomass.The vegetation biomass showed a pattern that more biomass were in underground part,also showed that under the disturbance of Plateau Zokor,the ratio of underground biomass declined and the aboveground biomass showed an inverse pattern.【Conclusion】The results of this study explored its impact mechanism to provide theoretical basis for maintaining ecological balance,promoting the construction of ecological civilization and formulating grassland protection policies.