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.

Rapidly rising temperatures in the Arctic might cause a greater release of greenhouse gases (GHGs) to the atmosphere. To study the effect of warming on GHG dynamics, we deployed open-top chambers in a subarctic tundra site in Northeast European Russia. We determined carbon dioxide (CO ), methane (CH ), and nitrous oxide (N O) fluxes as well as the concentration of those gases, inorganic nitrogen (N) and dissolved organic carbon (DOC) along the soil profile. Studied tundra surfaces ranged from mineral to organic soils and from vegetated to unvegetated areas. As a result of air warming, the seasonal GHG budget of the vegetated tundra surfaces shifted from a GHG sink of -300 to -198 g CO -eq m to a source of 105 to 144 g CO -eq m . At bare peat surfaces, we observed increased release of all three GHGs. While the positive warming response was dominated by CO , we provide here the first in situ evidence of increasing N O emissions from tundra soils with warming. Warming promoted N O release not only from bare peat, previously identified as a strong N O source, but also from the abundant, vegetated peat surfaces that do not emit N O under present climate. At these surfaces, elevated temperatures had an adverse effect on plant growth, resulting in lower plant N uptake and, consequently, better N availability for soil microbes. Although the warming was limited to the soil surface and did not alter thaw depth, it increased concentrations of DOC, CO and CH in the soil down to the permafrost table. This can be attributed to downward DOC leaching, fueling microbial activity at depth. Taken together, our results emphasize the tight linkages between plant and soil processes, and different soil layers, which need to be taken into account when predicting the climate change feedback of the Arctic.

Morphological and physiological parameters of 76 vascular plant species typical for Northern Europe were analyzed using Grime's classification. species (competitors) have high levels of canopy height, leaf dry weight, and maximal lateral spread. species (ruderal) have low leaf dry weight, longer flowering period, high rate of photosynthetic capacity and respiration, and high nitrogen content in the leaves. Stress-tolerant ( ) species prevailing in habitats with limited resources are small and have low rate of photosynthetic activity and respiration. Principal component analysis (PCA) ordination showed a clear separation of species of different plant functional types according to their morphological and physiological parameters. The first PCA axis showed close relationship with the rate of respiration and photosynthetic activity and allowed us to differentiate from species. The second PCA axis correlated with morphological parameters associated with the size of plants and allowed us to differentiate species from and species. Using PCA ordination, we developed a model that determines plant functional types in Northern Europe and analyzed plant functional types of several species that are not presented in Grime's classification. The proposed model has higher accuracy (84%) compared to similar models designed for other climatic zones.

No abstract

No abstract