关键词: 植被原生演替, 植物-土壤反馈, 植物相互作用, 冰川退缩区

Abstract: Plant-soil feedback is a key link for revealing the dynamics of terrestrial communities, thus laying a foundation to improve our understanding on the interactions among different plant groups and on the vegetation successional trajectories. We explored the relationships between soils and dominant plant species at three stages of the glacier retreat area of the Gongga Mountain including the early succession (5-10 years), mid-term succession (30-40 years), and late succession (80-100 years). The results showed that: (1) Plant-soil feedback significantly affected plant biomass in the native soil. Hippophae rhamnoidesgrew worst in the native soil of the early succession, with a negative plant-soil feedback coefficient. In the middle succession, the feedback coefficient of Populus purdomii tended to be zero. Abies fabri grew best in native soil at the late succession, with a positive feedback coefficient. (2) The competition interaction index between the early succession species H. rhamnoses and species of middle and late succession was negative, while it closed to zero for mid-succession species P. purdomii and Salix rehderiana, and was positive for the late succession species A. fabriand Picea brachytyla mixed with early and mid-succession species. Therefore, plant-soil feedback shifted from negative in early succession, neutral in mid-term succession, to positive in late succession. The early-succession species H. rhamnoides promoted the growth of species in later stages. P. purdomiiand S. rehderianain the mid-succession stage had no interaction with early and late succession species. Late-succession species A. fabriand P. brachytylawere more conducive to competing with early and mid-succession species. The results suggest that plant-soil feedback and plantplant interaction together drive the rapid succession of plant community up to the climax community in the glacier retreat area of Gongga Mountain.

Key words: vegetation primary succession, plant-soil feedback, plant-plant interaction, glacier retreat area.