An integrated pan-tropical biomass map using multiple reference datasets.
We combined two existing datasets of vegetation aboveground biomass (AGB) (Proceedings of the National Academy of Sciences of the United States of America, 108, 2011, 9899; Nature Climate Change, 2, 2012, 182) into a pan-tropical AGB map at 1-km resolution using an independent reference dataset of field observations and locally calibrated high-resolution biomass maps, harmonized and upscaled to 14 477 1-km AGB estimates. Our data fusion approach uses bias removal and weighted linear averaging that incorporates and spatializes the biomass patterns indicated by the reference data. The method was applied independently in areas (strata) with homogeneous error patterns of the input (Saatchi and Baccini) maps, which were estimated from the reference data and additional covariates. Based on the fused map, we estimated AGB stock for the tropics (23.4 N-23.4 S) of 375 Pg dry mass, 9-18% lower than the Saatchi and Baccini estimates. The fused map also showed differing spatial patterns of AGB over large areas, with higher AGB density in the dense forest areas in the Congo basin, Eastern Amazon and South-East Asia, and lower values in Central America and in most dry vegetation areas of Africa than either of the input maps. The validation exercise, based on 2118 estimates from the reference dataset not used in the fusion process, showed that the fused map had a RMSE 15-21% lower than that of the input maps and, most importantly, nearly unbiased estimates (mean bias 5 Mg dry mass ha(-1) vs. 21 and 28 Mg ha(-1) for the input maps). The fusion method can be applied at any scale including the policy-relevant national level, where it can provide improved biomass estimates by integrating existing regional biomass maps as input maps and additional, country-specific reference datasets.
Centre for Geo-Information, Wageningen University, Droevendaalsesteeg 3, 6708PB, Wageningen, The Netherlands.
Valerio
V
Avitabile
Centre for Geo-Information, Wageningen University, Droevendaalsesteeg 3, 6708PB, Wageningen, The Netherlands.
Martin
M
Herold
Centre for Geo-Information, Wageningen University, Droevendaalsesteeg 3, 6708PB, Wageningen, The Netherlands.
Gerard B M
GB
Heuvelink
School of Geography, University of Leeds, University Road, Leeds, West Yorkshire, LS2 9JZ, UK.|Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK.
Simon L
SL
Lewis
School of Geography, University of Leeds, University Road, Leeds, West Yorkshire, LS2 9JZ, UK.
Oliver L
OL
Phillips
Carnegie Institution for Science, 260 Panama St., Stanford, CA, 94305, USA.
Gregory P
GP
Asner
Joint Remote Sensing Research Program, The University of Queensland, Brisbane, Qld, 4072, Australia.|Department of Science, Information Technology and Innovation, Remote Sensing Centre, GPO Box 5078, Brisbane, Qld, 4001, Australia.
John
J
Armston
Organismic and Evolutionary Biology, Harvard University, 26 Oxford St, Cambridge, MA, 02138, USA.|Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK.
Peter S
PS
Ashton
Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK.
Lindsay
L
Banin
FRM Ingenierie, 60 rue Henri Fabre, 34130, Mauguio - Grand Montpellier, France.
Nicolas
N
Bayol
Institute of Geography, The University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, UK.
Nicholas J
NJ
Berry
Isotope Bioscience Laboratory, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium.
Pascal
P
Boeckx
ECOSUR-Campeche, Av. Rancho Polígono 2A, Parque Industrial Lerma, Campeche, CP 24500, México.
Bernardus H J
BH
de Jong
Centre for Geo-Information, Wageningen University, Droevendaalsesteeg 3, 6708PB, Wageningen, The Netherlands.
Ben
B
DeVries
School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK.
Cecile A J
CA
Girardin
Isotope Bioscience Laboratory, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium.|Laboratory for Wood Biology and Xylarium, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080, Tervuren, Belgium.
Elizabeth
E
Kearsley
The RSPB Centre for Conservation Science, The Lodge, Potton Road, Sandy, Bedfordshire, SG19 2DL, UK.
Jeremy A
JA
Lindsell
School of Geography, University of Leeds, University Road, Leeds, West Yorkshire, LS2 9JZ, UK.
Gabriela
G
Lopez-Gonzalez
Centre for Ecosystem Science, The University of New South Wales, Sydney, 2052, NSW, Australia.
Richard
R
Lucas
School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK.
Yadvinder
Y
Malhi
School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK.
Alexandra
A
Morel
Institute of Geography, The University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, UK.
Edward T A
ET
Mitchard
Universidade Estadual de Campinas, Rua Monteiro Lobato 255, Campinas, SP CEP 13083-970, Brazil.
Laszlo
L
Nagy
School of Geography, University of Leeds, University Road, Leeds, West Yorkshire, LS2 9JZ, UK.
Lan
L
Qie
SarVision, Agro Business Park 10, 6708 PW, Wageningen, The Netherlands.
Marcela J
MJ
Quinones
Institute of Geography, The University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, UK.
Casey M
CM
Ryan
Universiti Brunei Darussalam, Jln Tungku Link, Gadong, BE1410, Brunei Darussalam, Brunei.
Slik J W
SJ
Ferry
Center for International Forestry Research, PO Box 0113 BOCBD, Bogor, 16000, Indonesia.
Terry
T
Sunderland
Centro Euro-Mediterraneo sui Cambiamenti Climatici, Iafes Division, via Pacinotti 5, Viterbo, Italy.
Gaia Vaglio
GV
Laurin
Centro Euro-Mediterraneo sui Cambiamenti Climatici, Iafes Division, via Pacinotti 5, Viterbo, Italy.
Roberto Cazzolla
RC
Gatti
Department of Innovation of Biological Systems, Tuscia University, Via S. Camillo de Lellis, Viterbo, Italy.
Riccardo
R
Valentini
Isotope Bioscience Laboratory, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium.
Hans
H
Verbeeck
Center for International Forestry Research, PO Box 0113 BOCBD, Bogor, 16000, Indonesia.
Arief
A
Wijaya
Centre for Biological Sciences, the University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK.
Simon
S
Willcock
D018533:Biomass; D066264:Datasets as Topic; D008377:Maps as Topic; D008962:Models, Theoretical; D014197:Trees; D014329:Tropical Climate
REDD+; aboveground biomass; carbon cycle; forest inventory; forest plots; remote sensing; satellite mapping; tropical forest