This book features a comprehensive series of the overview articles on all relevant aspects of forest structure estimation from space and related fields. The overview articles in this book discuss the importance of the derived products for earth system science and policy, the latest earth observation system and techniques, aspects of ground data collection for contextualisation and validation and the consistent generation of estimates from multiple data stream. Previously published in Surveys in Geophysics, Volume 40, Issue 4, 2019 The chapters âAspects of Forest Biomass in the Earth System: Its Role and Major Unknownsâ, âThe Role and Need for Space-Based Forest Biomass-Related Measurements in Environmental Management and Policyâ, âRecent Advances in Forest Observation with Visual Interpretation of Very High-Resolution Imageryâ, âSpecies Matter: Wood Density Influences Tropical Forest Biomass at Multiple Scalesâ, âInnovations in Ground and Airborne Technologies as Reference and for Training and Validation: Terrestrial Laser Scanning (TLS)â, âNew Opportunities for Forest Remote Sensing Through Ultra-High-Density Drone Lidarâ, âThe Importance of Consistent Global Forest Aboveground Biomass Product Validationâ, and âA Joint ESA-NASA Multi-mission Algorithm and Analysis Platform (MAAP) for Biomass, NISAR, and GEDIâ are available as open access articles under a CC BY 4.0 license at link.springer.com