Abstract: Taking the evergreen broad-leaved forest in Dudong, Sanjiang county, Guangxi province as the research object, the size characteristics of gaps and the effects of gaps on the regeneration of tree species, shrubs, herbs and vines were analyzed. The results showed that the expanded gap area accounted for 71.7% of the sample plot area, and the canopy gap area accounted for 52.9% of the sample plot area. The sequence difference of important values of Acer metcalfii in and outside the gap was -35, and the positive regeneration response was very significant. In the shrub survey, the regeneration response was significant positive regeneration. It can be seen that the forest gap has the most obvious impact on the regeneration of Acer metcalfii, and the dominance will gradually increase. The significant value sequence differences of Elaeocarpusa japonicus and Ficus heteromorpha were -14 and -12, which showed significant positive regeneration. The sequence differences of Sloanea chingiana, Acer fabri and Beilschmiedia tsangii were -6, -9, -5, showing moderate positive regeneration. The corresponding shrub regeneration showed negative regeneration or no significant regeneration, and the dominance gradually decreased in the subsequent disturbance. The regeneration strategies of Stewartia gemmata, Michelia maudiae, Betula utilis, Hartia villosa, Manglietia conifera and Manglietia conifera were negative regeneration, and the corresponding shrub regeneration showed negative regeneration or no significant regeneration. In their subsequent development, their dominance gradually decreased and were gradually replaced by other tree species. The regeneration response of liana and herbaceous plants in and outside the gap was also significant.

Key words: Northern Guangxi, broad-leaved evergreen forests, gap, regeneration