Satellite Remote Sensing for Above-Ground Biomass Mapping of Community Forests: Enhancing Income Streams through Carbon Credits

Forests are an essential contributor to food security and income generation in many parts of the tropics. Community-managed Forest areas offer an opportunity to combine the conservation and economic use of forests by local actors. Communities can diversify their income streams by proofing sustainable use and participating in a carbon credit program. However, monitoring above-ground biomass (AGB) and carbon stocks in these plots can be challenging and costly. Thus, a narrative review was conducted of satellite remote sensing methods for assessing AGB on a plot level with the aim to reduce monitoring costs and enhance the feasibility of carbon projects.
Optical multispectral sensors, such as Landsat and Sentinel-2, provide valuable data for estimating AGB in these plots. However, precision and saturation issues need to be addressed. Higher-resolution optical data from commercial constellations such as RapidEye and Dove can offer more detailed information but may imply higher costs. The incorporation of Synthetic Aperture Radar (SAR) sensors, such as ALOS PALSAR and Sentinel-1, permits AGB estimation even in areas with persistent cloud cover, providing valuable insights into the agricultural landscape. LiDAR sensors, including ICESat-2 and GEDI, offer detailed information on the vertical distribution of AGB and can enhance precision in biomass mapping. Future missions, such as NASA's NISAR and ESA's BIOMASS, hold promise for improved SAR and LiDAR data.
Combined sensor optical data and LiDAR provide the most accurate results for AGB data at the plot level. Using only Landsat 8, the RMSE for AGB was 66%, 50% for LiDAR, and 49% for a combination of Landsat 8 and LiDAR. This approach facilitates the establishment of cost-effective monitoring, reporting, and verification (MRV) systems, enabling effective participation in carbon offset programs and enhancing the viability of plot-based carbon projects.