Advances in Amazonian Peatland Discrimination With Multi-Temporal PALSAR Refines Estimates of Peatland Distribution, C Stocks and Deforestation

Authors
Date Issued
2021-11Date Online
2021-11Language
enType
Journal ArticleReview status
Peer ReviewISI journal
Accessibility
Open AccessUsage rights
CC-BY-4.0Metadata
Show full item recordCitation
Bourgeau-Chavez, L.L., Grelik, S.L., Battaglia, M.J., Leisman, D.J., Chimner, R.A., Hribljan, J.A., Lilleskov, E.A., Draper, F.C., Zutta, B.R., Hergoualc’h, K., Bhomia, R.K. and Lähteenoja, O. 2021. Advances in Amazonian Peatland Discrimination With Multi-Temporal PALSAR Refines Estimates of Peatland Distribution, C Stocks and Deforestation. Frontiers in Earth Science 9: 676748. https://doi.org/10.3389/feart.2021.676748
Permanent link to cite or share this item: https://hdl.handle.net/10568/115850
Abstract/Description
There is a data gap in our current knowledge of the geospatial distribution, type and extent of C rich peatlands across the globe. The Pastaza Marañón Foreland Basin (PMFB), within the Peruvian Amazon, is known to store large amounts of peat, but the remoteness of the region makes field data collection and mapping the distribution of peatland ecotypes challenging. Here we review methods for developing high accuracy peatland maps for the PMFB using a combination of multi-temporal synthetic aperture radar (SAR) and optical remote sensing in a machine learning classifier. The new map produced has 95% overall accuracy with low errors of commission (1–6%) and errors of omission (0–15%) for individual peatland classes. We attribute this improvement in map accuracy over previous maps of the region to the inclusion of high and low water season SAR images which provides information about seasonal hydrological dynamics. The new multi-date map showed an increase in area of more than 200% for pole forest peatland (6% error) compared to previous maps, which had high errors for that ecotype (20–36%). Likewise, estimates of C stocks were 35% greater than previously reported (3.238 Pg in Draper et al. (2014) to 4.360 Pg in our study). Most of the increase is attributed to pole forest peatland which contributed 58% (2.551 Pg) of total C, followed by palm swamp (34%, 1.476 Pg). In an assessment of deforestation from 2010 to 2018 in the PMFB, we found 89% of the deforestation was in seasonally flooded forest and 43% of deforestation was occurring within 1 km of a river or road. Peatlands were found the least affected by deforestation and there was not a noticeable trend over time. With development of improved transportation routes and population pressures, future land use change is likely to put South American tropical peatlands at risk, making continued monitoring a necessity. Accurate mapping of peatland ecotypes with high resolution (<30 m) sensors linked with field data are needed to reduce uncertainties in estimates of the distribution of C stocks, and to aid in deforestation monitoring.
AGROVOC Keywords
Subjects
FOREST MANAGEMENT;Countries
PeruRegions
South AmericaOrganizations Affiliated to the Authors
Michigan Technological University; USDA Forest Service Northern Research Station; University of Leeds; Arizona State University; Spatial Informatics Group; SERVIR-Amazonia; Center for International Forestry ResearchInvestors/sponsors
United States Agency for International DevelopmentCollections
- CIFOR publications [7805]