Species and structural diversity of trees at the structural type level

Area of Science:

• Ecology
• Forestry
• Biodiversity Research

Background:

• Spatial characteristics of forest structure and species diversity are crucial for ecological understanding but remain understudied.
• Forest community formation, ecological processes, and functions depend on species and structural diversity.

Purpose of the Study:

• To analyze the diversity of structural types in natural forests near the Tropic of Cancer.
• To propose a new method for classifying trees into 15 structural types based on spatial relationships.

Main Methods:

• Utilized the uniform angle index (W), mingling (M), and dominance (U) distributions.
• Applied four common species diversity indices to analyze structural type diversity.
• Examined spatial relationships among neighboring trees to define structural types.

Main Results:

• Species mixture increased exponentially across distribution classes, with abundance and richness showing an initial rise then slight decline.
• Distribution patterns ranged from highly clustered to random, with M distributions shifting from inverted J to J shapes.
• W distributions approximated normal, M distributions showed J shapes, and U distributions were consistently around 0.2.

Conclusions:

• The study reveals species and structural diversity at the tree structural type level, expanding knowledge of forest biodiversity.
• The proposed method contributes to biodiversity monitoring in terrestrial ecosystems.
• Findings suggest higher standards for simulating, reconstructing, and managing near-natural forest structures.