The global network of tree diversity experiments “TreeDivNet”. Each experimental site is represented by one pie chart (some experiments have multiple sites). The sizes of the pie charts correspond to the respective tree species pool of the experiment. Based on information from TRY (retrieved in December 2019; Kattge et al. 2011), the representation of different mycorrhizal types in tree species is indicated by different colours. This dataset will be made available to all TreeDivNet members.