Walker, Wayne: Woodwell Climate Research Center (Project Lead)
Baccini, Alessandro (Ale): Boston University (Co-Investigator)
Project Funding:
2014 - 2018
NRA: 2014 NASA: Carbon Monitoring System
Funded by NASA
Abstract:
In response to the implications that high uncertainties associated with traditional approaches to forest carbon accounting have, not only for the credibility of REDD+, but also for the advancement of biospheric modeling and carbon cycle science, the main goal of this research is to investigate the potential for annual changes in the aboveground carbon density (ACD) of forests to be estimated directly, consistently, and with measurable accuracy across large areas using an array of existing commercial off-the-shelf and NASA remote sensing assets. The geographic focus is the country of Mexico where members of the proposal team have been working closely with the Mexican government since 2011 to assist in advancing their forest monitoring capacity as part of a USAID-supported project to Reduce Emissions from Deforestation and Forest Degradation in Mexico (USAID/M-REDD). The specific objectives are to: (1) Quantify the certainty with which extensive field, off-the-shelf airborne LiDAR, and MODIS satellite data can be used synergistically to estimate wall-to-wall changes in ACD at a resolution of 500 m across Mexico over a 15-year period (2001-2015). This objective expands on the work of Baccini et al. (2012) who successfully combined field, ICESat GLAS LiDAR, and MODIS optical data sets for single-epoch mapping of pantropical ACD. Here we replace spaceborne GLAS LiDAR with off-the-shelf airborne LiDAR and combine time-series mapping with change-point analysis to enable annual ACD change estimation, (2) Quantify the certainty with which extensive field, off-the-shelf airborne LiDAR, and VIIRS satellite data can be used synergistically to estimate wall-to-wall changes in ACD at a resolution of 375 m across Mexico over 5-year period (2012-2016). As NASA’s second-generation moderate-resolution imaging radiometer, VIIRS extends and improves upon MODIS; yet the performance of VIIRS data for large-area ACD and ACD change mapping, has not been demonstrated, (3) Quantify the certainty with which extensive field, off-the-shelf airborne LiDAR, and Landsat 5-8 satellite data can be used synergistically to estimate wall-to-wall changes in ACD for the Mexican states of Chihuahua, Oaxaca, Campeche, Yucatan, and Quintana Roo over a 15-year period (2001-2015). While acknowledging the increasing demand for large-area ACD estimates at resolutions ranging from 10s to 100s of meters, we seek to more closely examine Landsat performance, particularly the inverse relationship that appears to exist between resolution and accuracy, and (4) Conduct an independent accuracy assessment of the ACD change products produced in Objectives 1-3 as well as of derivative estimates of gross emissions. We will leverage permanent plot data from the Mexico National Inventory of Forest and Soil (INFyS), intensive field and micrometeorological measurements from the Mexico network of eddy covariance flux towers (MexFlux), and deforestation data from Hansen et al. (2013), among other data sources.
The ACD change products we propose to produce here represent a fundamentally new way of quantifying carbon fluxes that will significantly reduce uncertainty while leading to a more complete understanding of terrestrial carbon cycling. Unlike conventional approaches, which focus on deforestation leaving degradation unaccounted for, the proposed approach provides for a unique estimates of gross emissions at the pixel level, integrating losses due to deforestation, degradation, and other disturbances with gains due to growth. The work is expected to transform operational carbon accounting and, in doing so, drive the science, and ultimately the policy, forward. Within Mexico itself, the opportunity exists, not only to impact MRV system development at the national level through the involvement of proposal team members in the USAID/M-REDD project, but also at the jurisdictional level through relationships with the GCF and member states Chiapas and Campeche.
Publications:
Baccini, A., Walker, W., Carvalho, L., Farina, M., Houghton, R. A. 2019. Response to Comment on "Tropical forests are a net carbon source based on aboveground measurements of gain and loss". Science. 363(6423). DOI: 10.1126/science.aat1205
Baccini, A., Walker, W., Carvalho, L., Farina, M., Sulla-Menashe, D., Houghton, R. A. 2017. Tropical forests are a net carbon source based on aboveground measurements of gain and loss. Science. 358(6360), 230-234. DOI: 10.1126/science.aam5962
Walker, W. S., Gorelik, S. R., Baccini, A., Aragon-Osejo, J. L., Josse, C., Meyer, C., Macedo, M. N., Augusto, C., Rios, S., Katan, T., de Souza, A. A., Cuellar, S., Llanos, A., Zager, I., Mirabal, G. D., Solvik, K. K., Farina, M. K., Moutinho, P., Schwartzman, S. 2020. The role of forest conversion, degradation, and disturbance in the carbon dynamics of Amazon indigenous territories and protected areas. Proceedings of the National Academy of Sciences. 117(6), 3015-3025. DOI: 10.1073/pnas.1913321117
More details may be found in the following project profile(s):
