Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.Green leaves are fundamental for the functioning of terrestrial ecosystems. Their pigments are the predominant signal seen from space. Nitrogen uptake and carbon assimilation by plants and the decomposability of leaves drive biogeochemical cycles. Animals, fungi and other heterotrophs in ecosystems are fuelled by photosynthate, and their habitats are structured by the stems on which leaves are deployed. Plants invest photosynthate and mineral nutrients in the construction of leaves, which in turn return a revenue stream of photosynthate over their lifetimes. The photosynthate is used to acquire mineral nutrients, to support metabolism and to re-invest in leaves, their supporting stems and other plant parts.There are more than 250,000 vascular plant species, all engaging in the same processes of investment and reinvestment of carbon and mineral nutrients, and all making enough surplus to ensure continuity to future generations. These processes of investment and re-investment are inherently economic in nature [1][2][3] . Understanding how these processes vary between species, plant functional types and the vegetation of different biomes is a major goal for plant ecology and crucial for modelling how nutrient fluxes and vegetation boundaries will shift with land-use and climate change. Data set and parametersWe formed a global plant trait network (Glopnet) to quantify leaf economics across the world's plant species. The Glopnet data set spans 2,548 species from 219 families at 175 sites (approximately 1% of the extant vascular plant species). The coverage of traits, species and sites is at least tenfold greater than previous data compilations [4][5][6][7][8][9][10][11] , extends to all vegetated continents, and represents a wide range of vegetation types, from arctic tundra to tropical rainforest, from hot to cold deserts, from boreal forest to grasslands. Site elevation ranges from below sea level (Death Valley, USA) to 4,800 m. Mean annual temperature (MAT) ranges from 216.5 8C to 27.5 8C; mean annual rainfall (MAR) ranges from 133 to 5,300 mm per year. This cove...

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.

Summary• Leaf carbon capture strategies of native and exotic invasive plants were compared by examining leaf traits and their scaling relationships at community and global scales.• Community-level leaf trait data were obtained for 55 vascular plant species from nutrient-enriched and undisturbed bushland in Sydney, Australia. Global-scale leaf trait data were compiled from the literature for 75 native and 90 exotic invasive coexisting species.• At the community level, specific leaf area (SLA), foliar nitrogen and phosphorus ( N mass and P mass ) and N:P ratio were significantly higher for exotics at disturbed sites compared with natives at undisturbed sites, with natives at disturbed sites being intermediate. SLA, N mass and P mass were positively correlated, with significant shifts in group means along a common standardized major axis (SMA) slope. At the global scale, invasives had significantly higher N mass , P mass , assimilation rate ( A mass and A area ) and leaf area ratio (LAR) than natives. All traits showed positive correlations, with significant shifts in group means along a common slope. For a given SLA, invasives had higher A mass (7.7%) and N mass (28%).• Thus, exotic invasives do not have fundamentally different carbon capture strategies from natives but are positioned further along the leaf economics spectrum towards faster growth strategies. Species with leaf traits enabling rapid growth will be successful invaders when introduced to novel environments where resources are not limited.

The effects of biological invasions are most evident in isolated oceanic islands such as the Hawaiian Archipelago, where invasive plant species are rapidly changing the composition and function of plant communities. In this study, we compared the specific leaf area (SLA), leaf tissue construction cost (CC), leaf nutrient concentration, and net CO assimilation (A) of 83 populations of 34 native and 30 invasive species spanning elevation and substrate age gradients on Mauna Loa volcano in the island of Hawaii. In this complex environmental matrix, where annual precipitation is higher than 1500 mm, we predicted that invasive species, as a group, will have leaf traits, such as higher SLA and A and lower leaf CC, which may result in more efficient capture of limiting resources (use more resources at a lower carbon cost) than native species. Overall, invasive species had higher SLA and A, and lower CC than native species, consistent with our prediction. SLA and foliar N and P were 22.5%, 30.5%, and 37.5% higher, respectively, in invasive species compared to native ones. Light-saturated photosynthesis was higher for invasive species (9.59 μmol m s) than for native species (7.31 μmol m s), and the difference was larger when A was expressed on a mass basis. Leaf construction costs, on the other hand, were lower for the invasive species (1.33 equivalents of glucose g) than for native species (1.37). This difference was larger when CC was expressed on an area basis. The trends in the above traits were maintained when groups of ecologically equivalent native and invasive species (i.e., sharing similar life history traits and growing in the same habitat) were compared. Foliar N and P were significantly higher in invasive species across all growth forms. Higher N may partially explain the higher A of invasive species. Despite relatively high N, the photosynthetic nitrogen use efficiency of invasive species was 15% higher than that of native species. These results suggest that invasive species may not only use resources more efficiently than native species, but may potentially demonstrate higher growth rates, consistent with their rapid spread in isolated oceanic islands.

Introduced African grasses are invading the grasslands of the Venezuelan savannas and displacing the native grasses. This work, which is part of a program to understand the reasons for the success of the African grasses, specifically investigates whether introduced and native grasses differ in some photosynthetic characteristics.The responses to photon flux density, leaf temperature, leaf-air vapour pressure difference and leaf water potential of leaf photosynthetic rate of two introduced African C grasses (Hyparrhenia rufa and Melinis minutiflora) and of a lowland and a highland population of a native Venezuelan grass (Trachypogon plumosus) grown under controlled conditions were compared. These responses in all three species were typical of tropical C pasture grasses. The introduced grasses had higher maximum leaf conductance, net photosynthetic rates, and optimum temperature (H. rufa only) for photosynthesis than T. plumosus. However, T. plumosus was able to continue photosynthesis to lower leaf water potentials than the two introduced grasses, and the efficiency which it utilized water, light and mineral nutrients to fix carbon were similar to those of the introduced grasses.The higher rates of leaf photosynthesis of the introduced grasses contributed to, but only partially explained, the higher growth rates compared to T. plumosus. The higher growth rates and nutrient concentration of the introduced grasses are consistent with their ability to establish rapidly, compete successfully for resources, and displace T. plumosus from moist, fertile sites. Conversely, the slower growth rate, lower nutrient concentrations, and superior water relations characteristics are consistent with the capacity of T. plumosus to resist invasion by introduced grasses in poorer sites.

The African grass Hyparrhenia rufa has established itself successfully in South American savannas (Llanos) and displaced dominant native grasses such as Trachypogon plumosus from the wetter and more fertile habitats. Several ecophysiological traits have been related to the higher competitive capacity of H. rufa. To further analyze the behavior of both species, their growth, biomass allocation, physiological and architectural responses to defoliation and water stress were compared under controlled conditions. Although total, aerial and underground biomass decreased under defoliation in both grasses, increases in clipped-leaf biomass and area compensated for defoliation in H. rufa but not in T. plumosus. This difference was due mainly to a higher proportion of assimilates being directed to leaf and tiller production and a higher leaf growth rate in the African grass as compared to T. plumosus, which showed incrased senescence under frequent defoliation. In both species, water stress ameliorated the effects of defoliation. The ability to compensate for defoliated biomass in H. rufa is possibly related to its long coevolution with large herbivores in its original African habitat and is apparently one of the causes of its success in Neotropical savannas.

Plant invasion by Neotropical Melastomataceae is prominent in Hawaii. To understand life history traits of four successful invasive Melastomataceae, two shade-intolerant herbs (Arthrostema ciliatum and Tibouchina herbacea) and two shade-tolerant woody species (Clidemia hirta, a shrub, and Miconia calvescens, a tree) were subjected to three light levels and two watering regimes in a greenhouse. Plant height, leaf number and area, biomass allocation, relative growth rate (RGR), carbon assimilation (A), leaf nutrient content, leaf construction costs (CC), specific leaf mass (SLM), and leaf spectral properties were determined at the end of the experimental period. Plant size, total biomass, RGR, A, CC, and SLM decreased, whereas leaf light transmittance and leaf N increased under low light in all species. The effects of water stress were weaker than light-stress effects. Relative growth rate of herbs grown in sun and partial shade (0.046 and 0.033 g g-1 d-1, respectively) was higher than in the woody species (0.027 and 0.020 g g-1 d-1). Woody species allocated more biomass to leaf production than herbs, which allocated more biomass to stem production. Shade increased allocation of biomass to leaves, and water stress increased the root-shoot ratio in all species. Partial shade increased leaf area ratios more in the herbs (140%) than in woody species (68%). Miconia calvescens and C. hirta had higher leaf absorbance (92%) than both herbs (79%). Maximum A under all light treatments was similar in all species, and there was substantial acclimation to the different light levels. Leaf construction cost was higher in the apparently long-lived leaves of the woody species. Relative growth rate, carbon allocation, and SLM showed larger changes to light and water stress than A and related photosynthetic parameters. All species showed responses qualitatively similar to those of other tropical species including the high acclimation potential to light, but the herbs exhibited the largest quantitative responses. When compared with a large group of native species, the four melastomes appear to be better suited to capture and use light, which is consistent with their rapid spread in mesic and disturbed Hawaiian environments.

Two perennial tussock grasses of savannas were compared in a glasshouse study to determine why they differed in their ability to withstand frequent, heavy grazing; Cenchrus ciliaris is tolerant and Themeda triandra is intolerant of heavy grazing. Frequent defoliation at weekly intervals for six weeks reduced shoot biomass production over a subsequent 42 day regrowth period compared with previously undefoliated plants (infrequent) in T. triandra, but not in C. ciliaris. Leaf area of T. triandra expanded rapidly following defoliation but high initial relative growth rates of shoots were not sustained after 14 days of regrowth because of reducing light utilising efficiency of leaves. Frequently defoliated plants were slower in rate of leaf area expansion and this was associated with reduced photosynthetic capacity of newly formed leaves, lower allocation of photosynthate to leaves but not lower tiller numbers. T. triandra appears well adapted to a regime where defoliation is sufficiently infrequent to allow carbon to be fixed to replace that used in initial leaf area expansion. In contrast, C. ciliaris is better adapted to frequent defoliation than is T. triandra, because horizontally orientated nodal tillers are produced below the defoliation level. This morphological adaptation resulted in a 10-fold higher leaf area remaining after defoliation compared with similarly defoliated T. triandra, which together with the maintenance of moderate levels of light utilising efficiency, contributed to the higher leaf area and shoot weight throughout the regrowth period.