Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research—from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology—from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle.EEA Santa CruzFil: Jucker, Tommaso. University of Bristol. School of Biological Sciences; Reino UnidoFil: Fischer, Fabian Jörg. University of Bristol. School of Biological Sciences; Reino UnidoFil: Chave, Jérôme. Laboratoire Évolution et Diversité Biologique (EDB); FranciaFil: Chave, Jérôme. Université Toulouse; FranciaFil: Coomes, David A. University of Cambridge. Conservation Research Institute; Reino UnidoFil: Caspersen, John. University of Toronto. Institute of Forestry and Conservation; Canadá.Fil: Ali, Arshad. Hebei University. College of Life Sciences. Forest Ecology Research Group; China.Fil: Loubota Panzou, Grace Jopaul. Université de Liège, Gembloux Agro-Bio Tech; BélgicaFil: Loubota Panzou, Grace Jopaul. Université Marien Ngouabi. Faculté des Sciences et Techniques. Laboratoire de Biodiversité, de Gestion des Ecosystèmes et de l'Environnement (LBGE); Republica del CongoFil: Feldpausch, Ted R. University of Exeter. College of Life and Environmental Sciences; Reino UnidoFil: Falster, Daniel. University of New South Wales Sydney. Evolution & Ecology Research Centre; Australia.Fil: Usoltsev, Vladimir A. Ural State Forest Engineering University. Department of Forestry; Rusia.Fil: Usoltsev, Vladimir A. Botanical Garden of the Ural Branch of Russian Academy of Sciences. Department of Forest Dynamics; Rusia.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Xiang, Wenhua. Central South University of Forestry and Technology. Faculty of Life Science and Technology; China
