Abstract:

Aims: This study analyzes changes in species composition, stand structure, and diversity of Jiulian Mountains 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 dynamics plot in Jiulian Mountains, Jiangxi Province. We classified trees into three growth stages (saplings: 1 cm ≤ DBH < 5 cm; treelets: 5 cm ≤ DBH < 10 cm; adult trees: DBH ≥ 10 cm) to examine post-snow community dynamics. 

Results: The results revealed 13,308 woody plants (47 families, 87 genera, and 185 species) in 2008, which increased to 17,116 individuals (41 families, 76 genera, and 178 species) by 2022. From 2008 to 2022, the density of individuals increased by 39.4% for saplings, 9.7% for treelets, and 4.4% for adult 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 Shannon-Wiener diversity index at the sapling stage, were significantly higher than in 2008. From 2008 to 2022, the number of rare species at the sapling stage decreased from 76 to 61 species, while the number of common species increased from 40 to 46 species. In 2022, the mean DBH at the 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 (IV) of pioneer species increased in sapling and treelet stages, while IV 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. Although overall diversity increased, the reduction in mean DBH indicates that the snow disaster had long-term impacts. 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