Assessing Carbon Stocks in Cambodian Mangroves: Differences Among Dominant and Rare Mangrove Species

Abstract Mangrove ecosystems in Cambodia are vital blue carbon sinks, yet accurate quantification of their carbon stocks is hindered by a lack of species-specific data. While carbon assessments typically focus on dominant species such as Rhizophora spp. and Avicennia spp., this nano-review highlights the potential distinct contributions of rare mangrove species, including Heritiera littoralis, Xylocarpus granatum, and the critically endangered Bruguiera hainesii. We synthesize evidence indicating that these rare species likely enhance both above- and below-ground carbon pools through functional traits such as high wood density (>0.9 g cm⁻³), slow-decaying litter, and unique root architectures. Current allometric equations, derived from common species, may therefore underestimate carbon stocks in forests containing rare trees. Despite their potential significance, direct measurements for rare mangroves in Cambodia are absent, representing a critical knowledge gap. This review underscores the implications for blue carbon accounting, conservation, and restoration, arguing that integrating species-specific carbon data is essential for accurate national inventories, effective climate finance projects, and biodiversity-informed mangrove management. Keywords: Mangrove carbon stocks, rare species, Cambodia, Allometric equations, blue carbon accounting, Wood density, Soil organic carbon, Species-specific traits