Revealing the Assembly Mechanism of Island Herpetofauna Communities Using Metacommunity Theory
Jianxiong Li, Wenlong Qi, Shuran Li, Lei Xie, Yongpu ZhangABSTRACT
Aim
Disentangling the relative roles of environmental filtering, dispersal limitation, and biotic interactions in shaping island community assembly is a central goal in modern ecology. However, island biogeography studies have rarely quantified biotic filtering or explicitly incorporated functional traits to evaluate how abiotic environments structure communities. To address this gap, we conducted a comprehensive analysis of herpetofauna co‐occurrence patterns and biogeographical variation across islands.
Location
Coastal islands of southern Zhejiang, China.
Methods
Using herpetofauna survey data collected from 36 coastal islands between October 2021 and September 2025, we characterised island biogeographical features based on island attributes and land‐cover composition. Hierarchical modelling of species communities (HMSC) was applied to partition the effects of environmental variables, spatial structure, and species co‐occurrence on island community assembly. Species traits, phylogenetic relationships and residual covariance were jointly incorporated to infer potential interspecific interactions.
Results
Community assembly of island herpetofauna was predominantly driven by environmental filtering. The strength and nature of filtering differed between amphibians and reptiles. Reproductive traits, adult microhabitat preferences, and activity patterns were associated with intercept, distance to mainland, altitude and shape index. After accounting for environmental filtering, residual species associations became weaker. We detected no strong competitive exclusion or facilitative associations, contrary to the expectation of intensified competition on resource‐limited island.
Main Conclusions
Our findings show that biogeographic features structure insular herpetofauna communities by acting on species traits, particularly reproductive strategies. The absence of strong species interactions challenges the assumption that competition necessarily intensifies on islands. From a conservation perspective, maintaining environmental heterogeneity that supports functionally diverse life‐history strategies provides a mechanistic foundation for sustaining island herpetofauna, complementing single‐species approaches. This study advances a trait‐based understanding of island community assembly and offers empirical guidance for the conservation of island biodiversity.