【摘要】 本研究以内蒙古典型草原重要物种冰草为目标植物，研究邻居植物（冰草、大针茅、克氏针茅）、土壤接种物（冰草、羊草、大针茅和克氏针茅根际土壤）及其交互作用对目标植物生物量、植物-土壤反馈效应值（FV）及邻居效应强度指数（NIntA）的影响，以探究竞争作用对植物-土壤反馈效应的影响及其作用机制。双因素分析结果表明：邻居植物、土壤接种物及其交互作用均对冰草生物量、FV和NIntA有显著影响。土壤接种物的主效应及单样本t-检验分析结果表明，大针茅根际土壤接种物处理的冰草生物量最高，FV显著小于0（负反馈），NIntA显著小于0（竞争作用）；克氏针茅根际土壤接种物处理下，冰草的FV与0之间无显著差异而NIntA显著大于0（促进作用）；羊草根际土壤接种物处理下，冰草生物量最低，FV显著大于0（正反馈），NIntA显著小于0（竞争作用）。邻居植物的单样本t-检验分析表明，在冰草-大针茅混种条件下，FV和NIntA均显著小于0；冰草-克氏针茅混种条件下，FV和NIntA均显著大于0。交互作用的结果表现为：当邻居植物为冰草、大针茅时，均是在大针茅根际土壤接种物处理下冰草生物量最高，FV最低；当邻居植物为克氏针茅时，在克氏针茅根际土壤接种物处理下冰草生物量和NIntA最高。综合分析竞争和植物-土壤反馈结果表明，冰草在大针茅较优的群落，其种群数量会缩小，有利于维持群落的物种多样性，而在克氏针茅占优的群落，其种群数量会增加，成为优势种群。更多还原

【Abstract】 In this study, Agropyron cristatum, an important species in the typical steppe of Inner Mongolia, was used as the target plant, the effects of neighboring plants(Agropyron cristatum, Stipa grandis, and Stipa krylovii), soil inoculants(rhizosphere soils of Agropyron cristatum, Leymus chinensis, Stipa grandis, and Stipa krylovii), and their interactive effects on the biomass, plant-soil feedback value(FV), and neighbor-effect intensity index(NInt A) were studied, in order to explore the impact of competition on plant-soil feedback effects and its mechanisms. The results of the two-factor analysis indicate that neighboring plants, soil inoculants, and their interactions had significant effects on the biomass, FV, and NInt A of Agropyron cristatum. The main effect analysis and the single-sample t-test analysis of soil inoculants showed that the biomass of Agropyron cristatum was the highest under the treatment of Stipa grandis rhizosphere soil inoculation, FV was significantly less than 0(negative feedback), and NInt A was significantly less than 0(competitive effect). Under the treatment of Stipa krylovii rhizosphere soil inoculant, there was no significant difference between FV and 0 of Agropyron cristatum, while NInt A was significantly greater than 0(facilitative effect). Under the treatment of Leymus chinensis rhizosphere soil inoculant, the biomass of Agropyron cristatum was the lowest, FV was significantly greater than 0(positive feedback), and NInt A was significantly less than 0(competitive effect). The single-sample t-test analysis of neighboring plants showed that under the mixed planting condition of Agropyron cristatum and Stipa grandis, both FV and NIntA were significantly less than 0. Under the mixed planting condition of Agropyron cristatum and Stipa krylovii, both FV and NInt A were significantly greater than 0. The interaction results showed that when the neighboring plants were Agropyron cristatum or Stipa grandis, the biomass of Agropyron cristatum was the highest and FV was the lowest under the treatment of Stipa grandis rhizosphere soil inoculation.When the neighboring plant was Stipa krylovii, the biomass and NInt A of Agropyron cristatum were the highest under the treatment of Stipa krylovii rhizosphere soil inoculation. The results of comprehensive analysis of competition and plant-soil feedback showed that the population of Agropyron cristatum in the better community of Stipa grandis would be reduced, which was conducive to maintaining the species diversity of the community, while in the dominant community of Stipa krylovii, the number of its population of Agropyron cristatum would be increased, and become the dominant population.更多还原