Species diversity and distribution pattern of venerable trees in tropical Jianfengling National Forest Park (Hainan, China)

Abstract

Venerable trees are precious natural-cum-cultural heritage and an important component of regional biodiversity, with significant social, cultural and ecological values. A thorough understanding of their spatial patterns in relation to environmental factors can foster co-management for conservation and sustainable resource use. The Jianfengling National Forest Park in tropical China is a unique and rare primary tropical forest protected area with exceptionally high biodiversity and a rich endowment of venerable trees. This study evaluated the venerable tree stock regarding botanical makeup and factors shaping spatial patterns. We collected detailed tree data (species, age, dimensions, location, etc.) and environmental variables (elevation, slope and soil). The environmental variations were analyzed concerning tree abundance, species richness and tree age. The results identified 2134 venerable trees from 72 species, 55 genera and 30 families. Lithocarpus fenzelianus dominated with maximum importance value, followed by Cyclobalanopsis patelliformis, Madhuca hainanensis, Altingia obovata and Castanopsis tonkinensis. The top-ranking species were predominantly Fagaceae members. The age pattern demonstrated an inverted J-shape, with mainly 100-299 years trees and a few >500 years. DBH, tree height, and crown width displayed an approximately normal distribution. Spatial distributions by age tiers were uneven, with more in the northeast part. The altitudinal gradient significantly influenced the spatial patterns of tree abundance and species richness. The unimodal distribution marked tree and species concentration at circa 600 m mid-elevation. The findings have implications for venerable-tree conservation and management in tropical protected areas with similar threatened and remnant-tree status.