Forest Biomass Assessment Integrating Field Inventory and Optical Remote Sensing Data: A Systematic Review

Forests are the main reservoir of terrestrial carbon and thus play a significant role in the global carbon budget. To quantify the forest carbon stock, it is essential to assess the forest biomass. The regular monitoring of forest biomass is necessary to understand the carbon source/sink nature of the forests. Integration of field inventory with remote sensing (RS) data offers an efficient and reliable method for large-area forest aboveground biomass (AGB) estimation and mapping. The availability of the Earth observation data has made it feasible to quantify forest carbon stocks from local to global scales.The availability of optical satellite data for the past five decades has led to its extensive use in forest biomass studies. Spectral reflectance and spectral indices derived from optical RS data are used as redictor variables for AGB estimation. However, cloud cover and saturation of spectral values limit the use of optical RS data in AGB studies. Despite the limitations, optical RS data has been extensively tested and used for forest biomass/carbon assessment from local to global levels due to its long legacy. In this context, the present review highlights the utility of optical RS data in forest AGB estimation using various approaches.