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.

Root:shoot (R:S) biomass partitioning is one of the keys to the plants' ability to compensate for limiting resources in the environment and thus to survive and succeed in competition. In adult plants, it can vary in response to many factors, such as nutrient availability in the soil or reserves in the roots from the previous season. The question remains whether, at the interspecific level, reserves in seeds can affect seedlings' R:S ratio in a similar way. Proper allocation to resource‐acquiring organs is enormously important for seedlings and is likely to determine their survival and further success. Therefore, we investigated the effect of seed mass on seedling R:S biomass partitioning and its interaction with nutrient supply in the substrate. We measured seedling biomass partitioning under two different nutrient treatments after 2, 4, 6, and 12 weeks for seventeen species differing in seed mass and covering. We used phylogenetically informed analysis to determine the independent influence of seed mass on seedling biomass partitioning. We found consistently lower R:S ratios in seedlings with higher seed mass. Expectedly, R:S was also lower with higher substrate nutrient supply, but substrate nutrient supply had a bigger effect on R:S ratio for species with higher seed mass. These findings point to the importance of seed reserves for the usage of soil resources. Generally, R:S ratio decreased over time and, similarly to the effect of substrate nutrients, R:S ratio decreased faster for large‐seeded species. We show that the seed mass determines the allocation patterns into new resource‐acquiring organs during seedling development. Large‐seeded species are more flexible in soil nutrient use. It is likely that faster development of shoots provides large‐seeded species with the key advantage in asymmetric above‐ground competition, and that this could constitute one of the selective factors for optimum seed mass.

Summary Phenology has emerged as key indicator of the biological impacts of climate change, yet the role of functional traits constraining variation in herbaceous species’ phenology has received little attention. Botanical gardens are ideal places in which to investigate large numbers of species growing under common climate conditions. We ask whether interspecific variation in plant phenology is influenced by differences in functional traits. We recorded onset, end, duration and intensity of initial growth, leafing out, leaf senescence, flowering and fruiting for 212 species across five botanical gardens in Germany. We measured functional traits, including plant height, absolute and specific leaf area, leaf dry matter content, leaf carbon and nitrogen content and seed mass and accounted for species’ relatedness. Closely related species showed greater similarities in timing of phenological events than expected by chance, but species' traits had a high degree of explanatory power, pointing to paramount importance of species’ life‐history strategies. Taller plants showed later timing of initial growth, and flowered, fruited and underwent leaf senescence later. Large‐leaved species had shorter flowering and fruiting durations. Taller, large‐leaved species differ in their phenology and are more competitive than smaller, small‐leaved species. We assume climate warming will change plant communities’ competitive hierarchies with consequences for biodiversity.

Perennial herbaceous species form their above‐ground parts every year anew and discard them before the advent of winter. The senescence of above‐ground structures is thus an inevitable part of their life cycle. This is also a key process that determines photosynthetic gain late in the season and the economy of soil‐borne nutrients. Here we address patterns and drivers of the shoot senescence of perennial herbaceous plants. We present a comparative study of 231 temperate species, ranging from spring ephemeroids to species senescing in late autumn, in a common botanical garden collection. We assessed senescence by measuring size decline in the autumn part of the season. There were two main directions of variation in senescence trajectories: the pace–date axis, separating early and fast senescing species from late and slowly senescing species, and the shape‐asynchrony axis, separating species with accelerating and synchronised senescence from constant senescence asynchronous among individual shoots. While accelerating senescence late in the season can be due to passive effects of the environment (e.g. frost), accelerating senescence early in the season is likely to be an indication of an active process driven by the enzymatic activity of the plant. The pace and shape of shoot senescence were associated with both leaf‐ and shoot‐level traits. Species having leaves with high dry matter content senesced linearly and with higher asynchrony. Species with a larger specific leaf area senesced earlier and faster, while tall plants and plants with monocyclic shoots senesced later and in a more synchronous and accelerating manner. Species from different habitats varied in their senescence patterns. Forest species postpone their senescence relative to open‐habitat species, presumably to boost their photosynthetic balance. We did not confirm the hypothesis that plants from nutrient‐poor habitats senesce earlier to retain soil‐borne nutrients before the winter. Synthesis. Shoot senescence in herbaceous plants is a neglected phenomenon in its own right, which bears only superficial similarity to autumn leaf shedding in trees. Individual species differ strongly in the pace, shape and synchrony of their senescence trajectories, with a potential bearing on the carbon and nutrient dynamics of their habitats.