高寒草甸土壤微生物群落功能多样性对广布弓背蚁蚁丘扰动的响应

为了解蚂蚁在高寒草甸生态系统中的功能和作用,评估和认识高寒草甸生态系统的健康状况和稳定性,利用Biolog-ECO生态板法对蚁丘干扰后高寒草甸土壤理化性质以及土壤微生物功能多样性进行研究分析,结果表明,1)蚁丘扰动后0~10 cm土层土壤有机质、全氮、速效氮、速效磷、速效钾含量均显著高于蚁丘10~20 cm土层(P<0.05),而蚁丘扰动与土层深度的交互作用对理化性质均无显著影响(P>0.05);2)蚁丘干扰后高寒草甸土壤微生物多样性指数(Shannon-Weiner指数、Pielou指数、McIntosh指数和底物碳源利用数)有所增加;3)主成分分析表明蚁丘干扰对土壤微生物功能多样性产生了影响,改变了微生物代谢功能特征,土壤微生物利用的主要碳源是碳水化合物、氨基酸类和羧酸类;4)冗余分析表明土壤养分影响土壤微生物碳源代谢特征和功能。因此,由于蚂蚁的挖掘活动、有机质的累积等改变了蚁丘土壤微环境,进而改变了土壤微生物的碳源利用类型和代谢功能。

Responses of soil microbial community functional diversity to Camponotus herculeanus ant-hill disturbance in alpine meadows

To understand the function of the ants in the health and stability of an alpine meadow ecosystem we analyzed the effects of ant-hill disturbance on soil physical and chemical properties and microbial functional di-versity in an alpine meadow using the Biolog-ECO microplate method.The results showed that while organic matter,total nitrogen,available nitrogen,available phosphorus and available potassium levels within the 0-10 cm soil depth were significantly higher than those in the 10-20 cm soil depth as expected (P <0.05),and that ant-hill disturbance had no significant effect on soil physicochemical properties (P >0.05).Ant-hill disturbance significantly improved soil microbial diversity index (specifically,values of Shannon-Weiner,Pielou,McIn-tosh and carbon utilization efficiency)and principal component analyses showed that ant-hill disturbance influ-enced soil microbial diversity and changed the microbial metabolism characteristics of soil microorganisms,to a status where carbohydrates,amino acids and carboxylic acid were the main carbon sources for the soil microbial community.Redundancy analyses indicated that metabolic rate and microbial functional diversity of soil micro-bial community was affected by soil nutrient levels.Therefore,the mining activities of the ants and associated accumulation of organic matter changed the soil microenvironment under the ant hills,resulting in changes to the soil microbial carbon source utilization and metabolism.