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Title: Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations

Abstract

Mapping and monitoring of forest carbon stocks across large areas in the tropics will necessarily rely on remote sensing approaches, which in turn depend on field estimates of biomass for calibration and validation purposes. Here, we used field plot data collected in a tropical moist forest in the central Amazon to gain a better understanding of the uncertainty associated with plot-level biomass estimates obtained specifically for the calibration of remote sensing measurements. In addition to accounting for sources of error that would be normally expected in conventional biomass estimates (e.g., measurement and allometric errors), we examined two sources of uncertainty that are specific to the calibration process and should be taken into account in most remote sensing studies: the error resulting from spatial disagreement between field and remote sensing measurements (i.e., co-location error), and the error introduced when accounting for temporal differences in data acquisition. We found that the overall uncertainty in the field biomass was typically 25% for both secondary and primary forests, but ranged from 16 to 53%. Co-location and temporal errors accounted for a large fraction of the total variance (>65%) and were identified as important targets for reducing uncertainty in studies relating tropical forest biomass tomore » remotely sensed data. Although measurement and allometric errors were relatively unimportant when considered alone, combined they accounted for roughly 30% of the total variance on average and should not be ignored. Lastly, our results suggest that a thorough understanding of the sources of error associated with field-measured plot-level biomass estimates in tropical forests is critical to determine confidence in remote sensing estimates of carbon stocks and fluxes, and to develop strategies for reducing the overall uncertainty of remote sensing approaches.« less

Authors:
 [1];  [2]; ORCiD logo [3];  [4];  [5];  [5];  [6];  [7]
  1. Canopy Remote Sensing Solutions, Florianopolis, SC (Brazil)
  2. California Inst. of Technology (CalTech), La Canada Flintridge, CA (United States). Jet Propulsion Lab.
  3. Oregon State Univ., Corvallis, OR (United States). Dept. of Forest Ecosystems & Society
  4. Univ. Federal de Sergipe (Brazil). Dept. de Engenharia Agricola
  5. Woods Hole Research Center, Falmouth, MA (United States)
  6. National Inst. for Space Research (INPE), Sao Jose dos Campos (Brazil)
  7. National Inst. for Research in Amazonia (INPA), Manaus (Brazil). Dept. of Environmental Dynamics
Publication Date:
Research Org.:
Oregon State Univ., Corvallis, OR (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Aeronautics and Space Administration (NASA); Brazilian Ministry of Education
OSTI Identifier:
1362036
Grant/Contract Number:
FG02-07ER64361
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Remote Sensing
Additional Journal Information:
Journal Volume: 9; Journal Issue: 1; Journal ID: ISSN 2072-4292
Publisher:
MDPI
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; forest inventory; allometry; uncertainty; error propagation; Amazon; ICESat/GLAS

Citation Formats

Gonçalves, Fabio, Treuhaft, Robert, Law, Beverly, Almeida, André, Walker, Wayne, Baccini, Alessandro, dos Santos, João, and Graça, Paulo. Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations. United States: N. p., 2017. Web. doi:10.3390/rs9010047.
Gonçalves, Fabio, Treuhaft, Robert, Law, Beverly, Almeida, André, Walker, Wayne, Baccini, Alessandro, dos Santos, João, & Graça, Paulo. Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations. United States. doi:10.3390/rs9010047.
Gonçalves, Fabio, Treuhaft, Robert, Law, Beverly, Almeida, André, Walker, Wayne, Baccini, Alessandro, dos Santos, João, and Graça, Paulo. Sat . "Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations". United States. doi:10.3390/rs9010047. https://www.osti.gov/servlets/purl/1362036.
@article{osti_1362036,
title = {Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations},
author = {Gonçalves, Fabio and Treuhaft, Robert and Law, Beverly and Almeida, André and Walker, Wayne and Baccini, Alessandro and dos Santos, João and Graça, Paulo},
abstractNote = {Mapping and monitoring of forest carbon stocks across large areas in the tropics will necessarily rely on remote sensing approaches, which in turn depend on field estimates of biomass for calibration and validation purposes. Here, we used field plot data collected in a tropical moist forest in the central Amazon to gain a better understanding of the uncertainty associated with plot-level biomass estimates obtained specifically for the calibration of remote sensing measurements. In addition to accounting for sources of error that would be normally expected in conventional biomass estimates (e.g., measurement and allometric errors), we examined two sources of uncertainty that are specific to the calibration process and should be taken into account in most remote sensing studies: the error resulting from spatial disagreement between field and remote sensing measurements (i.e., co-location error), and the error introduced when accounting for temporal differences in data acquisition. We found that the overall uncertainty in the field biomass was typically 25% for both secondary and primary forests, but ranged from 16 to 53%. Co-location and temporal errors accounted for a large fraction of the total variance (>65%) and were identified as important targets for reducing uncertainty in studies relating tropical forest biomass to remotely sensed data. Although measurement and allometric errors were relatively unimportant when considered alone, combined they accounted for roughly 30% of the total variance on average and should not be ignored. Lastly, our results suggest that a thorough understanding of the sources of error associated with field-measured plot-level biomass estimates in tropical forests is critical to determine confidence in remote sensing estimates of carbon stocks and fluxes, and to develop strategies for reducing the overall uncertainty of remote sensing approaches.},
doi = {10.3390/rs9010047},
journal = {Remote Sensing},
number = 1,
volume = 9,
place = {United States},
year = {Sat Jan 07 00:00:00 EST 2017},
month = {Sat Jan 07 00:00:00 EST 2017}
}

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