Species composition and community structure of woody species in typical evergreen broad-leaved forests in Conghua, Guangzhou, China

This study aimed to characterize the woody species composition and community structure of a typical southern subtropical evergreen broad-leaved forest in China, elucidate its succession pattern, species diversity, and development trend, and to provide a scientific basis for the refined management and biodiversity conservation of forest ecosystems in this region.

Sixteen permanent plots, each covering an area of 1 200 m², were established in a secondary forest in Conghua, Guangzhou, which had naturally regenerated after logging in the 1990s. All woody plants with a diameter at breast height (DBH)≥5 cm were surveyed within each plot. The species composition, species diversity, diameter-class structure, and vertical stratification of the community were systematically analyzed.

1) A total of 4 095 woody individuals (DBH≥5 cm) were recorded in the plots, belonging to 58 species, 46 genera and 34 families; and the families Lauraceae, Ebenaceae and Fagaceae were predominant; 2) Eight family and 11 genus distribution area types were identified, with tropical elements predominantly accounting for 64.71% of families and 65.22% of genera; 3) Twenty-three species had an importance value above 1%; the top six dominant tree species were Machilus chinensis, Diospyros morrisiana, Schima superba, Castanopsis faberi, Triadica cochinchinensis and Camphora parthenoxylon; and M. chinensis was absolutely dominant (importance value: 22.36%); 4) The diameter-class structure showed a typical reverse “J”-shaped distribution, indicating favorable community regeneration; 5) The vertical structure was stratified into four layers: sapling (2.5-9.3 m), sub-canopy (9.4-12.9 m), mid-canopy (13.0-16.5 m), and upper-canopy layers (16.6-25.8 m), trees in the sub- and mid-canopy layers together accounted for 64.96%, and species diversity decreased significantly with increasing canopy height; 6) The overall species diversity of the community was moderately high, but individual abundance was unevenly distributed among species, concentrated in a few dominant tree species.

This community represents a typical warm subtropical evergreen broad-leaved forest in the Pearl River Delta region. Currently in a mid-succession stage, it is characterized by generally small tree diameters, a stable structure, and a growing trend. Forest quality can be rapidly improved through target-tree management and enrichment planting with valuable tree species characteristic of middle and late succession stages.