Carbon emissions and Amazon forest degradation
Fire and logging has a lasting impact on forest carbon stocks and canopy structure in the Amazon.
Forest degradation continues to threaten carbon stocks in frontier forests along the Amazon arc of deforestation. Limited data on the magnitude of carbon losses and rates of carbon recovery following forest degradation have hindered carbon accounting efforts and contributed to incomplete national reporting to reduce emissions from deforestation and forest degradation (REDD+). The challenge to quantify degradation emissions using traditional field measurements stems from the heterogeneity and time-dependence of degradation impacts from fire and logging.
Published in: Quantifying long-term changes in carbon stocks and forest structure from Amazon forest degradation Environmental Research Letters, 13(6), 065013.
Rappaport, D. I., Morton, D. C., Longo, M., Keller, M., Dubayah, R., & dos-Santos, M. N. (2018).
We combined airborne lidar and Landsat time series over intact and degraded Amazon forests to develop the first comprehensive assessment of emissions factors for logged and burned Amazon forests to better integrate human degradation into carbon monitoring systems.
Our approach to disentangle the complex legacy of degradation by combining forest inventory, airborne lidar, and Landsat time series in the southern Amazon offers a blueprint to generate degradation emissions factors in other geographies and regional circumstances. On average, degraded forests contained 45.1% of the carbon stocks in intact forests, and differences persisted even after 15 years of regrowth. In comparison to logging, understory fires resulted in the largest and longest-lasting differences in ACD. Heterogeneity in burned forest structure varied by fire severity and frequency. Forests with a history of one, two, and three or more fires retained only 54.4%, 25.2%, and 7.6% of intact ACD, respectively, when measured after a year of regrowth. Airborne lidar also provides quantitative measures of habitat structure that can aid the estimation of co-benefits of avoided degradation. Notably, forest carbon stocks recovered faster than attributes of canopy structure that are critical for biodiversity in tropical forests, including the abundance of tall trees. We provide the first comprehensive look-up table of emissions factors for specific degradation pathways at standard reporting intervals in the Amazon. Estimated carbon loss and recovery trajectories provide an important foundation for assessing the long-term contributions from forest degradation to regional carbon cycling and advance our understanding of the current state of frontier forests.