在气候变化影响下，以针茅属植物为优势种的典型草原群落中葱属植物优势度日益增加，这种种群拓殖行为已成为内蒙古草原普遍的生态现象。在呼伦贝尔克鲁伦河流域，克氏针茅（Stipa krylovii）和多根葱（Allium polyrhizum）种群存在明显的年际消长动态。本项研究针对这一现象，拟对两个物种在群落中的优势度及其与干旱、盐碱程度和土壤氮素水平的相关关系进行观测与分析，并在此基础上，在温室中开展以干旱、盐碱和氮素水平为因子，设计克氏针茅和多根葱地下繁殖体单种和混种的盆栽控制实验，对比分析克氏针茅和多根葱的生理耐受性表现（光合特性、水分利用效率、抗氧化能力等）、竞争反应与生态适应策略（克隆繁殖特征、繁殖体休眠、根系构型等），揭示克氏针茅种群维持与多根葱种群拓殖的生理生态机制，对于理解和认识群落组合规则、生理忍耐与竞争型生活史对策、物种共存与多样性维持以及典型草原退化机理具有重要意义。

Under the influence of climatic change, the dominance of Allium plants is increasing in the typical steppe communities dominated by Stipa plants, and such population expansion has become a common ecological phenomenon in inner-Mongolia steppe zone. This is well exemplified by the inter-annual fluctuation of the dominance by Stipa krylovii and Allium polyrhizum in Kherlen river basin in Hulunbeir. To explore this phenomenon, we attempt to investigate the interrelationships of relative dominance of Stipa and Allium with the extent of drought and saline-alkali and soil nitrogen availability. In order to elucidate the underlying mechanism, we will carry out a pot experiment in greenhouse, in which monoculture and mixture of the two species are created using the belowground propagules of them, with drought, saline-alkali and soil nitrogen availability as factors. With the pot experiment, we intend to compare the physiological tolerance (photosynthetic properties, water use efficiency, and antioxidant capacity, etc.), competitive response and ecological adaptation strategy (clonal propagation, dormancy of propagules, root architectural plasticity, etc.), thereby to declare the eco-physiological mechanisms of Stipa population maintenance and Allium population expansion. Undoubtedly, all these research activities will be of significance for understanding community assembly rules, life history strategies including stress tolerance and competition strategy, species coexistence, plant diversity maintenance and even the mechanisms of grassland degradation.