B51I-07
Global trends and vulnerabilities of mangrove forests
Friday, 18 December 2015: 09:30
2004 (Moscone West)
Marc Simard1, Temilola E Fatoyinbo2, Victor H Rivera-Monroy3, Edward Castaneda3 and Rinku Roy Chowdhury4, (1)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (2)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (3)Louisiana State University, School of the Coast and the Enivronment, Department of Oceanography and Coastal Sciences, Baton Rouge, LA, United States, (4)Clark University, Geography, Worcester, MA, United States
Abstract:
Mangrove forests are located along Earth’s coastlines and estuaries within tropical and subtropical latitudes. They provide numerous services functioning as an extraordinary carbon sequestration system and serving as habitat and nursery for fish, crustaceans and amphibians. To coastal populations, they provide livelihood, food, lumber and act as an effective protection against tsunamis, storm surges and hurricanes. Their vulnerability to sea level rise is strongly related to their extraordinary ability to accumulate soils, which is in part related to their productivity and therefore canopy structure. As a first step to understand their vulnerability, we seek to understand mangrove dependencies on environmental and geophysical setting. To achieve this, we mapped mangrove canopy height and above ground biomass (AGB) at the Global scale. To identify mangrove forests, existing maps derived from a collection of Landsat data around the 2000 era were used. Using the Shuttle Radar Topography Mission elevation data collected in February of 2000, we produced a Global map of mangrove canopy height. The estimated heights were validated with the ICESat/Geoscience Altimeter System (GLAS) and in situ field data. Most importantly, field data were also used to derive relationships between canopy height and AGB. While the geographical coverage of in situ data is limited, ICESat/GLAS data provided extensive geographical coverage with independent estimates of maximum canopy height. These estimates were used to calibrate SRTM-estimates of height at the Global scale. We found the difference between GLAS RH100 and SRTM resulted from several sources of uncertainty that are difficult to isolate. These include natural variations of canopy structure with time, system errors from GLAS and SRTM, geo-location errors and discrepancies in spatial resolution. The Global canopy height map was trnasormed into AGB using the field-derived allometry. Depending on the scale of analysis and geographical location, accuracies in the order 2 to 4m in height was obtained with AGB accuracies below 20%.
