Gallagher, R. V.; D. S. Falster; B. S. Maitner; R. Salguero-Gomez; V. Vandvik; W. D. Pearse; F. D. Schneider; J. Kattge; J. Alroy; M. J. Ankenbrand; S. C. Andrew; M. Balk; L. M. Bland; B. L. Boyle; C. H. Bravo-Avila; I. Brennan; A. J. R. Carthey; R. Catullo; B. R. Cavazos; S. Chown; B. Fadrique; X. Feng; H. Gibb; A. H. Halbritter; J. Hammock; J. A. Hogan; H. Holewa; M. Hope; C. M. Iversen; M. Jochum; M. Kearney; A. Keller; P. Mabee; J. S. Madin; P. Manning; L. McCormick; S. T. Michaletz; D. S. Park; C. Penone; T. M. Perez; S. Pineda-Munoz; J. Poelen; C. A. Ray; M. Rossetto; H. Sauquet; B. Sparrow; M. J. Spasjevic; R. J. Tedford; J. A. Tobias; C. Violle; R. Walls; K. C. B. Weiss; M. Westoby; I. J. Wright and B. J. Enquist

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Despite the well-recognised importance of traits for addressing ecological and evolutionary questions, trait-based approaches still struggle with several basic data requirements to deliver openly accessible, reproducible, and transparent science. Here, we introduce the Open Traits Network (OTN) – a decentralised alliance of international researchers and institutions focused on collaborative integration and standardisation of the exponentially increasing availability of trait data across all organisms. The OTN embraces the use of Open Science principles in trait research, particularly open data, open source, and open methodology protocols and workflows, to accelerate the synthesis of trait data across the Tree of Life. Increased efforts at all levels – from individual scientists, research networks, scientific societies, funding agencies, to publishers – are necessary to fully exploit the opportunities offered by Open Science in trait research. Democratising access to data, tools and resources will facilitate rapid advances in the biological sciences and our ability to address pressing environmental and societal demands.