doi:10.1038/nindia.2016.7 Published online 20 January 2016
By analysing satellite images, researchers have estimated a forest’s biomass (the dry weight of plants) and carbon-sink potential1. This could help scientists better understand ecosystem processes and the global carbon cycle, and identify ways to conserve forests.
Trees absorb carbon dioxide from the atmosphere, including carbon dioxide generated by human activities. Traditional methods for estimating forest biomass involve measuring the sizes of trees, which is expensive and time-consuming. In contrast, remote sensing can estimate biomass quickly and cheaply.
By using a water-cloud model and microwave images from the Japanese Advanced Land Observing Satellite, the researchers estimated the biomass and the carbon-sink potential of teak and sal trees in Katerniaghat Wildlife Sanctuary, a tropical rain forest in India.
The estimated biomasses of sal forests ranged between 282.5 and 900 tons per hectare, whereas those for teak trees were between 325 and 950 tons per hectare. Although teak trees had a higher mean biomass than sal trees, the biomass of sal trees was higher than expected.
Young, fast-growing teak trees showed higher biomass increases and formed higher-density stands. However, mature sal trees absorbed as much carbon as teak trees. This knowledge will be useful for formulating carbon management plans.
Besides estimating the biomass and carbon content of a forest, the study stresses the need for conserving forest area and streamlining forest management plans, the researchers say.
1. Behera, M. D. et al. Above-ground biomass and carbon estimates of Shorea robusta and Tectona grandis forests using QuadPOL ALOS PALSAR data. Adv. Space Res. 57, 552–561 (2016)