aboveground biomass
; airborne sensing
; carbon emission
; data set
; deforestation
; environmental degradation
; forest fire
; forest inventory
; land use change
; lidar
; logging (timber)
; Amazonas [Brazil]
; Brazil
英文摘要:
Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, fire, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n = 359) and airborne lidar data (18,000�ha) assembled to date for the Brazilian Amazon. We developed statistical models relating inventory ACD estimates to lidar metrics that explained 70% of the variance across forest types. Airborne lidar-ACD estimates for intact forests ranged between 5.0 � 2.5 and 31.9 � 10.8�kg�C�m−2. Degradation carbon losses were large and persistent. Sites that burned multiple times within a decade lost up to 15.0 � 0.7�kg�C�m−2 (94%) of ACD. Forests that burned nearly 15�years ago had between 4.1 � 0.5 and 6.8 � 0.3�kg�C�m−2 (22–40%) less ACD than intact forests. Even for low-impact logging disturbances, ACD was between 0.7 � 0.3 and 4.4 � 0.4�kg�C�m−2 (4–21%) lower than unlogged forests. Comparing biomass estimates from airborne lidar to existing biomass maps, we found that regional and pantropical products consistently overestimated ACD in degraded forests, underestimated ACD in intact forests, and showed little sensitivity to fires and logging. Fine-scale heterogeneity in ACD across intact and degraded forests highlights the benefits of airborne lidar for carbon mapping. Differences between airborne lidar and regional biomass maps underscore the need to improve and update biomass estimates for dynamic land use frontiers, to better characterize deforestation and degradation carbon emissions for regional carbon budgets and Reduce Emissions from Deforestation and forest Degradation (REDD+). �2016. American Geophysical Union. All Rights Reserved.
Embrapa Agricultural Informatics, Campinas, Brazil; International Institute of Tropical Forestry, USDA Forest Service, Rio Piedras, Puerto Rico; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; NASA Goddard Space Flight Center, Greenbelt, MD, United States; Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia; Woods Hole Research Center, Falmouth, MA, United States; National Institute for Research in Amazonia, Manaus, Brazil; Brazilian Agricultural Research Corporation (Embrapa), Bras�lia, Brazil
Recommended Citation:
Longo M,, Keller M,, dos-Santos M,et al. Aboveground biomass variability across intact and degraded forests in the Brazilian Amazon[J]. Global Biogeochemical Cycles,2016-01-01,30(11)