Abstract:

Objective: From two levels of species group and species to research the spatial distribution pattern of different characteristics of dominant species group, also to research the spatial associations between groups and within groups and their laws of change with scales. To explore spatial distribution pattern of dominant species and the causes of intercorrelation of subtropical evergreen broad-leaved forest community in Dinghushan Mountain, further to reveal the coexistence and distribution of dominant species in communities, and to provide a theoretical basis for biodiversity conservation in this region. Method: Based on the survey data of the top 10 dominant species in the 20 hm² subtropical evergreen broad-leaved forest community in Dinghushan Mountain, the spatial distribution point patterns of species groups and within groups were analyzed using the relative neighborhood density index Ω_r, and the spatial correlation between species groups and within groups was analyzed using the multivariate point pattern g₁₂ equation. Result: 1) Aggregation distribution was not only dominant at the species level, but also the main type of spatial distribution pattern at the species group level. The degree of significant aggregation detected in each dominant species group showed a downward trend with the increase of detection scale. 2) The strategies of maintaining dominance of each characteristic dominant species group in the community were different, which reflected the difference of association among species groups. Diameter class dominant species group and quantitative dominant species group competed for survival resources with two different survival strategies respectively from large diameter class and high quantity. In the end, the two species had different spatial distribution and maintained their advantages together with their own characteristics, showing a significant negative correlation at all detection scales. The diameter class dominant species group and the diameter class and quantitative dominant species group were almost independent and unrelated at all detection scales. The quantitative dominant species group and the diameter class and quantitative dominant species group were in a complementary state in the vertical spatial distribution of the community, and in the same or similar spatial distribution in the horizontal space, there was a significant positive correlation at all scales. 3) There were differences in the spatial associations among the groups of characteristic dominant species: the spatial correlation among the dominant species in the diameter class group was mainly positive, and the spatial associations among species within the quantitative dominant species group were different, and the spatial associations of the two species (Castanopsis chinensis and Acmena acuminatissima) within the diameter class and quantitative dominant species group were significantly negative correlated. Conclusion: The spatial distribution pattern at the species group level were consistent with those at the species level. Aggregated distribution was still the main type of spatial distribution pattern of the community. The strategies of maintaining dominance in the community were different for each characteristic dominant species group, which reflected the differences in spatial association among the species groups. The diameter-class dominant species group and the quantitative dominant species group were complementary in horizontal space, and the two groups showed significant negative correlation at all detection scales. The quantitative dominant species group and the diameter class and quantitative dominant species group were complementary in vertical space and overlapping in horizontal space, and had significant positive correlation at all detection scales.

Key words: subtropical evergreen broad-leaved forest, dominant species group, spatial distribution pattern, spatial association, large scale permanent plot