Assessing mangrove canopy height and health changes in Puerto Rico post-Hurricane Maria using remote-sensing techniques

Abstract

Mangroves are critically important ecosystems that are highly vulnerable to hurricanes. This study assessed the impact of Hurricane Maria on mangrove canopy heights and vegetation at two sites in Puerto Rico—La Parguera (southwest) and the Northeast Ecological Corridor (northeast)—and examined factors influencing recovery. Using remote sensing techniques, including light detection and ranging (LiDAR) and normalized difference vegetation index (NDVI) analysis, we quantified canopy height loss and vegetation health changes over time. Results show a significant reduction in canopy height immediately after the hurricane, with greater damage in the Northeast Corridor site than in the La Parguera site. NDVI analysis revealed site-specific variation in post-hurricane recovery, with some areas exceeding pre-hurricane vegetation health despite initial losses. Recovery patterns appeared to be linked to pre-storm canopy height and potential human disturbances, such as land-use change and hydrologic alteration. The integration of LiDAR and NDVI provided complementary insights, with LiDAR capturing structural damage and NDVI reflecting vegetation health dynamics. This study highlights the value of remote sensing in evaluating mangrove resilience and identifying factors influencing recovery after extreme weather events.