Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Scientific Data art. 198 [ 11 p.] 2019 fdi:010077111 ENG Scientific Data ISI:000489560800001 10.1038/s41597-019-0196-1 https://www.documentation.ird.fr/hor/fdi:010077111 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-10/010077111.pdf 6 Horizon (IRD) Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS- based biomass products while developing new synergies between the RS and ground-based ecosystem research communities. 082 ; 126 ; 021 UR253 / UR123 Bolivie / Brésil / République Centrafricaine / Côte d'ivoire / Cameroun / Gabon / Ghana / Guyana / Indonésie / Libéria / Malaisie / Panama / Pérou / Suriname