Abstract:To explore the succession rule of karst secondary forest in central Guizhou, based on the fixed-point monitoring data in 2013-2019, the dynamic changes of niche and interspecific association of karst secondary forest in central Guizhou were studied, including community species composition, niche width, niche overlap and interspecific association. The results showed that the proportion of important value of constructive species decreased in 7 years, and the dominance of species, such as Serissa japonica and Viburnum foetidum, increased significantly. Zanthoxylum armatum and Rosa cymosa occupied a wide niche, while the niche width of Stachyurus yunnanensis and Serissa japonica and other species have increased resource availability, which narrowed their niche width. The proportion of species pairs with niche overlap less than 0.2 decreased, and the relationship of interspecific competition was more complex. The overall connectivity among main species changed from non-significant positive association to significant positive association, and the proportion of positive and negative association between most species increased. In the karst secondary forest community of central Guizhou, the competition among species was intense and gradually stable, and the connection between species was strengthened. In the process of positive succession, the dominance and competitiveness of shade tolerant and mesophily species, such as Serissa japonica and Viburnum foetidum increased, but some pioneer species, such as Rhamnus heterophylla and Campylotropis macrocarpa, declined due to insufficient competition. Therefore, these would provide a reference for vegetation restoration and rocky desertification control in karst areas.
