Characterizing Global Patterns of Mangrove Canopy Height and Aboveground Biomass Derived from SRTM Data

Abstract

Numerous studies have been done using remotely sensed data to produce global mangrove height and biomass maps; however, little is known about the worldwide pattern of mangroves in the Northern and Southern Hemispheres that corresponds to their height and biomass. The objective of this study was to investigate whether there is a specific pattern that can be seen between northern and southern mangroves according to height and biomass. Based on an empirical model, we processed Shuttle Radar Topographic Mission (SRTM) elevation data in combination with 450 field data points to produce a global mangrove height map and its corresponding aboveground biomass (AGB) per hectare at 30 m spatial resolution. We also refined the global mangrove area maps and provided a set of equations to determine the maximum mangrove height at any given latitude. Results showed that 10,639,916 ha of mangroves existed globally in the year 2000, with a total AGB of 1.696 Gt. Even though the areal coverage of mangroves was higher in the Northern Hemisphere, the total mangrove AGB was higher in the Southern Hemisphere. The majority of mangroves in both hemispheres were found to be between 6 and 8 m tall, although height distribution differed in each hemisphere. The global mangrove height equation for northern and southern mangroves produced from this study can be used by relevant stakeholders as an important reference for developing an appropriate management plan for the sustainability of the global mangrove ecosystem.