Standardised and harmonised biodiversity data and monitoring methods are required in order to assess how tropical forest biodiversity is evolving at the global scale, and what the drivers of change are. Collaborative efforts towards the development of such harmonised monitoring methods are carried out by national and regional forest agencies, the scientific and research community, and NGOs. These standardisation efforts are supported by the Essential Biodiversity Variables (EBV) concept that is currently developed by GEO-BON, and by Space Agencies and the Earth Observation research community at large. This sourcebook is developed by a wide group of forest researchers and practitioners, to promote the best operational monitoring practices based on scientific literature, and consensus. The first version of the biodiversity sourcebook was released during the IPBES Plenary 2017 and follows the 13th UNCBD Conference of Parties (COP) held in December 2016. Updates will be made on a yearly basis following policy, scientific, and technical developments. The biodiversity sourcebook is accessible in pdf format for free from the GOFC-GOLD Land Cover Office website and the GEO BON website.