A resilience dichotomy in mangrove forests: Native resistance versus exotic compensation to climatic and tidal extremes

Native and exotic mangrove trees are increasingly challenged by the synergistic pressures of climate change, yet the mechanisms defining their comparative resilience remain unresolved. This study characterizes a fundamental resilience dichotomy by analyzing a two-decade (1999–2019) dataset of litterfall biomass from a subtropical mangrove forest. Integrating causal screening with non-linear machine-learning approaches, we quantified how native (Avicennia marina, Kandelia obovata) and exotic (Sonneratia apetala, S. caseolaris) species partition carbon allocation in response to climatic and tidal extremes. Our results reveal that native species adopt a resistance-oriented strategy, prioritizing canopy structural persistence during wind and tidal anomalies; however, this stability is maintained at the cost of significantly suppressed reproductive output. In contrast, exotic species showed a compensatory-oriented strategy, characterized by accelerated leaf turnover under storms and high-temperature extremes, while maintaining stable reproductive continuity to ensure sustained function under ongoing stress. Notably, the increasing frequency of extremes triggers non-linear thresholds, leading to a functional decoupling between canopy maintenance and recruitment potential, particularly among native populations. This divergence provides a mechanistic basis for predicting shifts in ecosystem stability and underscores the importance of incorporating species-specific resilience traits into long-term conservation and management planning under intensifying climate volatility.