Abstract:

Aims: This study analyzes changes in species composition, stand structure, and diversity of Jiulianshan evergreen broad-leaved forests over 14 years following the 2008 southern snow disaster, revealing post-disaster community dynamics to inform forest restoration and sustainable management. 

Method: Based on two phytosociological surveys (2008 and 2022) in a 4 ha evergreen broad-leaved forest plot in Jiulianshan, Jiangxi Province. We classified trees into three growth stages (saplings: 1 cm≤DBH<5 cm; treelets: 5 cm≤DBH<10 cm; adults trees: DBH≥10 cm) to examine post-snow community dynamics. 

Results: The results revealed 13308 woody plants (47 families, 87 genera, 185 species) in 2008, which increased to 17116 individuals (41 families, 76 genera, 178 species) by 2022. From 2008 to 2022, increased by 39.4% for saplings, 9.7% for treelets, and 4.4% for adults trees, while basal area increased by 23.1%, 14.3%, and 3.7%, respectively. In 2022, overall species richness, as well as species richness and the Shannon-Wiener index at the sapling stage, were significantly higher than in 2008. In 2022, the number of rare species at the sapling stage decreased compared to 2008 (61 vs. 76 species), while common species increased (40 vs. 46 species). In 2022, the mean DBH at sapling stage significantly decreased compared to 2008, while mean tree height across all growth stages showed a significant increase. From 2008 to 2022, the importance values of pioneer species increased in sapling and treelet stages, while those of shade-tolerant species increased in the adult tree stage. 

Conclusion: From 2008 to 2022, the evergreen broad-leaved forest community exhibited a recovery trend after snow disaster disturbance, with a significant increase in sapling abundance and species richness serving as key drivers of regeneration. Despite increased overall diversity, the reduction in mean DBH indicates long-term impacts of the snow disaster. Following the snow disaster, the release of resources such as light and space increased pioneer species richness at the sapling stage, yet the community shifted toward greater dominance of shade-tolerant species.

Key words: snow disaster, evergreen broad-leaved forest, natural recovery, community dynamics