Abstract: Mangroves are among the most productive and biodiverse ecosystems globally, possessing substantial carbon sequestration capacity and providing a wide range of ecosystem services. Stand age is a critical parameter for predicting mangrove growth, carbon accumulation, and the changes in ecosystem services. However, current approaches for the estimation of mangrove age remain insufficiently developed, leading to considerable uncertainty in ecological assessments. This review synthesizes four major methodological pathways and their applicable conditions and limitations for mangrove age estimation, as well as the response patterns of ecological services to variations in forest age. Current approaches mainly include traditional field-based measurements, optical remote sensing time-series analysis, LiDAR-based structural inversion, and multi-source remote sensing integration. Traditional field-based methods can achieve high-precision individual tree dating at the plot scale, but their applicability is constrained by irregular growth rings in tropical species, limited spatial representativeness, and high sampling costs. Optical remote sensing approaches enable the identification of mangrove establishment years using long-term image time series and are therefore suitable for regional-scale age-class mapping. Nevertheless, their performance is strongly affected by cloud contamination, tidal fluctuations, mixed-pixel effects, and vegetation index saturation. LiDAR techniques provide canopy height and vertical structural information, offering important structural constraints for age inversion. However, their application is limited by insufficient spatial coverage and temporal continuity. Multi-source fusion approaches, which integrate temporal trajectories with structural parameters, represent an important direction for improving mangrove age estimation accuracy. Nevertheless, these methods still face challenges associated with scale mismatch among datasets, insufficient field validation, and complex uncertainty propagation. Existing studies indicate that the age structure of mangroves in China is jointly shaped by historical conservation, restoration programs, and regional climatic gradients. The proportion of artificially restored forests is relatively high, exhibiting a latitudinal gradient that increases from north to south, with the overall age structure tending toward rejuvenation. In response to current methodological limitations, future research should prioritize the establishment of long-term monitoring plots, integration of afforestation archives, synergistic inversion using multi-source remote sensing, development of regionalized parameter models, and comprehensive uncertainty assessment frameworks, ultimately supporting the construction of a national-scale mangrove age database. Mangrove stand age significantly regulates ecological functions such as carbon sequestration, coastal protection, and biodiversity conservation, which represents a key parameter for restoration planning and carbon offset assessment. This review provides both theoretical foundations and technical references for mangrove carbon sink assessment, ecological restoration evaluation, and coastal ecosystem management.

Key words: mangrove, stand age, remote sensing, ecosystem services