In typical alpine meadow of southern Gansu Province, five sampling sites by fertilizer diammonium phosphate (DAP) addition ranging from 0 g·m-2 to 120 g·m-2 were set in order to examine the response of soil ciliate communities to different concentrations of DAP. An investigation on the abundance and species richness of soil ciliates was carried out by non-flooded Petri dish, observation in vivo and three-level ten-fold dilution methods. Soil physicochemical factors including soil water content, pH value, contents of soil total nitrogen, total phosphorus and organic carbon at different sites were also measured. It was found that there was a total of 129 species belonging to 9 classes, 17 orders, 31 families and 46 genera. Lower species richness and diversity but higher ciliate abundance were observed in the soils with higher concentrations of DAP compared with the control. The dominant group Haptorida was substituted by Colpodida from the control to the soils with the increase of fertilizer application. The results of redundancy analysis indicated that the gradient changes of total phosphorus, soil temperature and water content were the main driving factors for the change of soil ciliate community distribution.
为研究磷酸氢二铵(DAP)添加对土壤纤毛虫群落结构的影响,于2012年4月在甘南高寒草甸选取典型样地,在0～120 g·m-2浓度区间内设置5个添加水平,采用“非淹没培养皿法”、活体观察法和“3级10倍环式稀释法”测定土壤纤毛虫物种数和密度,同时测定了土壤相关环境因子(含水量、pH值、总氮、总磷、有机碳).共获得土壤纤毛虫129种,隶属9纲17目31科46属.对照组的土壤纤毛虫物种数和物种多样性指数均大于施肥处理,且随着施肥量的增大,土壤纤毛虫物种数减少,物种多样性减小,但其密度随施肥量的增大而增加.对照土壤纤毛虫优势类群为刺钩目,随着施肥量的增大,土壤纤毛虫优势类群更新为肾形目.土壤纤毛虫群落结构和环境因子的冗余分析表明,总磷、土壤温度和含水量是影响甘南高寒草甸土壤纤毛虫群落分布的关键环境因子.
Keywords: alpine meadow; community structure; fertilization; redundancy analysis.