TY - JOUR
T1 - Spaceborne height models reveal above ground biomass changes in tropical landscapes
AU - Schlund, M.
AU - Kotowska, Martyna M.
AU - Brambach, Fabian
AU - Hein, Jonas
AU - Wessel, Birgit
AU - Camarretta, Nicolò
AU - Silalahi, Mangarah
AU - Surati Jaya, I. Nengah
AU - Erasmi, Stefan
AU - Leuschner, Christoph
AU - Kreft, Holger
N1 - Funding Information:
This work was supported in part by the German Federal Ministry for Economic Affairs and Energy (BMWi) through the project IKEBANA with the consortium of University of Göttingen, German Remote Sensing Data Center and Airbus Defence & Space GmbH under Grant 50EE1808 and by the German Research Foundation (DFG) in the framework of the research project EFForTS (CRC990). We thank local assistants for support with fieldwork, as well as village leaders, local plot owners, PT REKI, and the Indonesian Research Foundation (LIPI) for research permissions. This study was conducted using samples collected with the Collection Permits No. 2704/IPH.1/KS.02/X1/2012 and issued by the FRP-Kemenristek. Field work in Jambi province was carried out under research permit numbers 207/SIP/FRP/SM/VI/2012 and 46/E5/E5.4lS—P.EXT/2019. TanDEM-X data used within this work were provided by DLR under proposal XTI_VEGE7394. We acknowledge the use of concession data from the Ministry of Environment and Forestry, Directorate General of Forestry Planning and Environmental Management and the Ministry of Agriculture, Directorate General of Estate Crop, Jakarta, Indonesia. We acknowledge the use of data and/or imagery from NASA’s Fire Information for Resource Management System (FIRMS) ( https://earthdata.nasa.gov/firms ), part of the NASA Earth Observing System Data and Information System (EOSDIS).
Funding Information:
This work was supported in part by the German Federal Ministry for Economic Affairs and Energy (BMWi) through the project IKEBANA with the consortium of University of G?ttingen, German Remote Sensing Data Center and Airbus Defence & Space GmbH under Grant 50EE1808 and by the German Research Foundation (DFG) in the framework of the research project EFForTS (CRC990). We thank local assistants for support with fieldwork, as well as village leaders, local plot owners, PT REKI, and the Indonesian Research Foundation (LIPI) for research permissions. This study was conducted using samples collected with the Collection Permits No. 2704/IPH.1/KS.02/X1/2012 and issued by the FRP-Kemenristek. Field work in Jambi province was carried out under research permit numbers 207/SIP/FRP/SM/VI/2012 and 46/E5/E5.4lS?P.EXT/2019. TanDEM-X data used within this work were provided by DLR under proposal XTI_VEGE7394. We acknowledge the use of concession data from the Ministry of Environment and Forestry, Directorate General of Forestry Planning and Environmental Management and the Ministry of Agriculture, Directorate General of Estate Crop, Jakarta, Indonesia. We acknowledge the use of data and/or imagery from NASA's Fire Information for Resource Management System (FIRMS) (https://earthdata.nasa.gov/firms), part of the NASA Earth Observing System Data and Information System (EOSDIS).
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/10/1
Y1 - 2021/10/1
N2 - The area-wide estimation of aboveground biomass (AGB) and its changes as a proxy for the sequestration and emission of carbon are currently associated with high uncertainties. Here we combined interferometric synthetic aperture radar (InSAR) height models derived from TanDEM-X with repeated ground-based inventories from the years 2012 and 2019 to estimate InSAR height and AGB changes in a structurally diverse and dynamic landscape in Sumatra, Indonesia. The results suggested that the InSAR height models were highly accurate and the relationship between InSAR height and AGB change resulted in a coefficient of determination R2 of 0.65 and a cross-validated root mean square error (RMSE) of 2.38 Mg ha−1 year−1, equivalent to 13.32% of the actual AGB difference range. The estimated AGB changes with TanDEM-X were further related to the initial canopy height and fire activities in the study area. Initial canopy heights and the occurrences of fires had a significant effect on the AGB change. In general, low canopy heights tend to be associated with increasing AGB over time, whereas high canopy heights tend to be associated with stable or decreasing AGB. As expected, fires had a negative impact on the AGB changes being more pronounced in forest areas compared to oil palm concessions. The results of this study are relevant for the utilization of spaceborne InSAR height models and its potential to estimate canopy height and AGB change on large spatial scales. It was demonstrated that these changes can be related to their sources and ecosystem processes. This AGB change estimation technique can be used to model the impacts of fires on AGB change and carbon emissions, which are important for sustainable forest management.
AB - The area-wide estimation of aboveground biomass (AGB) and its changes as a proxy for the sequestration and emission of carbon are currently associated with high uncertainties. Here we combined interferometric synthetic aperture radar (InSAR) height models derived from TanDEM-X with repeated ground-based inventories from the years 2012 and 2019 to estimate InSAR height and AGB changes in a structurally diverse and dynamic landscape in Sumatra, Indonesia. The results suggested that the InSAR height models were highly accurate and the relationship between InSAR height and AGB change resulted in a coefficient of determination R2 of 0.65 and a cross-validated root mean square error (RMSE) of 2.38 Mg ha−1 year−1, equivalent to 13.32% of the actual AGB difference range. The estimated AGB changes with TanDEM-X were further related to the initial canopy height and fire activities in the study area. Initial canopy heights and the occurrences of fires had a significant effect on the AGB change. In general, low canopy heights tend to be associated with increasing AGB over time, whereas high canopy heights tend to be associated with stable or decreasing AGB. As expected, fires had a negative impact on the AGB changes being more pronounced in forest areas compared to oil palm concessions. The results of this study are relevant for the utilization of spaceborne InSAR height models and its potential to estimate canopy height and AGB change on large spatial scales. It was demonstrated that these changes can be related to their sources and ecosystem processes. This AGB change estimation technique can be used to model the impacts of fires on AGB change and carbon emissions, which are important for sustainable forest management.
KW - Aboveground biomass change
KW - Height models
KW - Interferometric synthetic aperture radar (InSAR) data
KW - TanDEM-X
KW - Tropical rainforest
KW - ITC-ISI-JOURNAL-ARTICLE
KW - ITC-HYBRID
KW - UT-Hybrid-D
UR - https://ezproxy2.utwente.nl/login?url=https://library.itc.utwente.nl/login/2021/isi/schlund_spa.pdf
U2 - 10.1016/j.foreco.2021.119497
DO - 10.1016/j.foreco.2021.119497
M3 - Article
AN - SCOPUS:85110035022
SN - 0378-1127
VL - 497
SP - 1
EP - 13
JO - Forest ecology and management
JF - Forest ecology and management
M1 - 119497
ER -