Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects.We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives. Geosphere-Biosphere Program (IGBP) and DIVERSITAS, the TRY database (TRY-not an acronym, rather a statement of sentiment; https ://www.try-db.org; Kattge et al., 2011) was proposed with the explicit assignment to improve the availability and accessibility of plant trait data for ecology and earth system sciences. The Max Planck Institute for Biogeochemistry (MPI-BGC) offered to host the database and the different groups joined forces for this community-driven program. Two factors were key to the success of TRY: the support and trust of leaders in the field of functional plant ecology submitting large databases and the long-term funding by the Max Planck Society, the MPI-BGC and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, which has enabled the continuous development of the TRY database.

Questions We investigated whether soils of small mounds resembled large mound or matrix soils, whether changes in plant composition reflected changes in soils, and the sequence in which plants colonize and disappear from mounds of increasing size. Location Miombo woodland in northwest Zimbabwe. Methods Macrotermitinae termitaria vary in size and soil nutrient concentrations, harbouring distinct woody plant assemblages, making them foci for plant and animal diversity, and also influencing primary, secondary and tertiary productivity. In spite of the importance of termitaria to heterogeneity and diversity, no studies have investigated changes in plant species assemblages as mound surface area increases to the point where mound vegetation is distinct from that of the matrix. We compared woody plant assemblages on 43 matrix plots with 95 Macrotermes termitaria across a range of surface areas, using ANOSIM, cluster analysis and MDS ordination. We compared soil nutrients, pH and clay, from ten large and ten small termitaria, and ten matrix sites. We also assessed how relative representation of large mound or matrix indicator species changed with mound area. Results Change was apparent even at mound sizes of >10 m2, where both soils and plant assemblages on mounds were significantly different to those of the matrix. Plant assemblages fell into two main groups at 20% similarity; the first comprised of matrix plots, mounds <10 m2 and some mounds between 10 and 30 m2; the second, the remainder of the mounds between 10 and 30 m2 and all mounds >30 m2. At 40% similarity, four groups emerged: matrix, mounds <10 m2, mounds 10–30 m2 and mounds >30 m2. Woody plant composition changed gradually as mound area increased. On termitaria <10 m2, only 25% of indicators were mound indicator species, but on mounds between 10 and 30 m2 in size, 62.5% were mound indicators. On termitaria >30 m2 in surface area, only mound indicator species were found. Conclusions Through termite activities in concentrating nutrients and clay, termitaria provide habitat for species usually excluded from the matrix. The process of mound building and the nature of the plants that establish on them seem to establish a positive feedback for establishment of other non‐woodland matrix species.

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