Evaluating the reliability of mangrove biomass allometric models: A global assessment

Abstract

Reliable allometric models are important for accurately estimating mangrove biomass and carbon stocks. Numerous mangrove allometric biomass models have been developed worldwide, but their quality, reliability, and applicability have never been systematically evaluated. The present study developed a reliability-screened global database of mangrove biomass allometric models through a comprehensive systematic review and standardized model reliability assessment framework. We screened 2431 records in accordance with PRISMA guidelines, resulting in 132 eligible publications containing 1676 primary allometric models. Models were evaluated using three complementary criteria: statistical performance, Sample Adequacy Ratio (SAR), and biological plausibility. Overall, 920 models satisfied all reliability criteria and were retained in the final reliability-screened global database. This database spans four decades (1983-2026) and covers 34 mangrove species from 32 countries. Researchers developed considerably more allometric models after 2000. Most studies focused on Southeast Asia. Research was strongly biased toward a limited number of species, particularly Avicennia marina and Rhizophora spp., whereas many mangrove species and regions remained poorly represented. Diameter at breast height was the dominant predictor variable, and aboveground biomass was the most frequently modelled component. The study also identified important gaps in taxonomic coverage, geographic representation, biomass components, and model validation practices. The validated global database provides a reliable reference for selecting allometric models and establishes a standardized benchmark for future mangrove biomass research, carbon accounting, blue carbon assessments, ecosystem restoration, and sustainable mangrove management.