Forest biomass

Matang's mangrove forests are harvested in rotation, with a 30 year cycle of harvesting ongoing for over 100 years. The wood is primarily used for charcoal production but also construction and hence carbon is stored in buildings but also released through charcoal burning. Carbon is also temporarily accumulated in the vegetation through growth of the forests and, longer term, in the soil and sediments through burial.

In the MAMAForest Project, the above ground biomass (AGB) of mangrove vegetation has been estimated using a combination of Japanese L-band SAR data in combination with height estimates generated from interferometric radar. These data have been acquired in 2000 from the Shuttle Radar Topographic Mission (SRTM) but also 2014 by the Tandem-X mission. Relationships established between the L-band SAR HV backscatter and AGB indicate a progressive and quite rapid increase up to about 60 Mg ha^-1 but then saturation occurs with no further increases in backscatter with AGB. Indeed, our studies indicate that the L-band HV and also HH backscatter decreases with increasing AGB beyond approximately 100 Mg ha^-1 because of greater scattering by the large root systems of the dominant Rhizophora mucronata. This decrease occurs in forests that are typically > approximately 10 m in height and hence this height threshold can be used to differentiate forests that are on an increasing or decreasing L-band HH and HV trajectory as the AGB increases for the forest stand.