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Vegetation is often classified through phytosociology, which defines floristically and ecologically coherent units identified by diagnostic species. Since species- and community-environment relations are regulated by plant functional traits, it is likely that phytosociology has a strong functional underpinning, although the past and current phytosociology does not explicitly tackle this issue. Here we provide an analysis of functional traits of 221 woody species from Northern Italy, diagnostic of 21 European woody vegetation classes (including alien dominated ones). We assessed whether the functional space occupied by selected species corresponds to the physiognomy and ecology of the vegetation they represent, and whether this could help to evaluate major threats, such as invasion by alien species. For each species we collected from Authors' datasets leaf trait data (leaf area, specific leaf area, leaf dry matter content, carbon to nitrogen ratio, leaf nitrogen content) and whole plant (plant height, seed mass) traits, and calculated Competitor, Stress-tolerant, Ruderal (CSR) scores. We identified the multidimensional functional trait space of diagnostic species and clustered classes according to their scores in the functional space, to check whether their physiognomy was coherently represented and mirrored in the CSR space. Lastly, we tested for differences between native and neophyte species and their overlap with classes. Diagnostic species mirrored the global spectrum of plant form and function, and classes showed a functional pattern coherent with their physiognomy and ecology. Evergreen dominated classes showed a similar convergence toward conservative characteristics and the stress-tolerant strategy, as opposed to deciduous forest classes that showed a tendency toward the competitive strategy. None of the classes showed a marked ruderal strategy, thus abiotic stress and biotic competition are the main ecological drivers affecting woody vegetation. Neophyte woody species exhibited relatively more competitive strategies compared to natives, and their invasion could be facilitated in resource-limited or mildly disturbed environments, should climate warming or increased nutrient availability occur. We demonstrated that plant traits and CSR strategies of woody diagnostic species reliably indicate the structure and functions of the phytosociological classes they represent, opening the way to the development of a "functional phytosociology". [ABSTRACT FROM AUTHOR]

Sulfur is an essential macronutrient for plant primary metabolism. Its availability can modulate plant growth in most terrestrial ecosystems. However, its relationship with other leaf and nutrient traits, and hence its contribution to plant functioning, remains unclear. We analysed leaf and nutrient traits for 740 vascular plant species growing in a wide range of environmental conditions in Northern Italy. We determined whether leaf sulfur content per unit leaf dry mass (LSC) is associated with leaf economics spectrum, and whether its distribution among functional types (growth forms, leaf life span categories, and Grime's CSR (Competitive, Stress-tolerant, Ruderal strategies) could help to elucidate adaptive differences within plant taxa. High LSC values were mainly associated with fastgrowing species representative of R- and C-strategy selection, thus the acquisitive extreme of plant economics, reflecting strong potential connections with ecosystem properties such as biomass production or litter decomposability. In general, LSC was significantly and positively correlated with leaf nitrogen content, and nitrogen to sulfur ratio was constant throughout growth forms, leaf life span and CSR strategies, and phylogenetic effects were evident. Our findings highlight that LSC variation is strongly associated with the leaf economics spectrum, suggesting that additional nutrients seldom included in functional analyses may also be embroiled within the context of plant economics. However, different ratios among nitrogen and sulfur may be expected across different plant families, suggesting that deeper insight from functional groups can provide a bridge between plant stoichiometry and ecology, useful for the evaluation of ecological responses to global change. [ABSTRACT FROM AUTHOR]

A detailed assessment of a pasture's functioning based on soil properties characterization, floristic composition, and 'functional summary' by evaluating competitor–stress tolerator–ruderal (CSR) strategies is provided for a doline in Central Italian Alps. A floristic survey was carried out at 35 sampling points, representative of the main topographic features, soil and vegetation types; the functional profile at the community level was evaluated by assessing for each species its Grime's CSR strategy; each point was characterized through soil profiles and topsoil (0–10 cm) sampling; pH, soil organic carbon and total nitrogen, available P, soil humus fraction, root density, bulk density, water content, and available water capacity were determined. Our study showed i) a strong relationship between vegetation, soil properties, topography, and grazing; ii) a prevalence of stress-tolerant strategies; iii) the ability of plant strategy variation to reflect the ecological parameters; and iv) the vegetation potentiality to be an indicator of environmental spatial variability. [ABSTRACT FROM AUTHOR]

• Grime's CSR strategy theory broadly explains the invasion success of alien plant species. • Invasive alien and native plant species occupy the same region within the CSR space. • Invasive alien plant species are true competitors. • CSR theory can be a viable tool for the risk assessment of invasive alien plant species. Invasive alien species (IAS) are the subset of naturalized species that cause greater impacts on biodiversity, ecosystem functions and services. However, despite management actions and eradication plans, their expansion worldwide is seemingly unstoppable. In this paper, based on a large dataset of 1039 records of IAS and native plant species representative of the extensive biogeographic diversity in Southern Europe, we tested the consistency of Grime' concept of CSR universal adaptive strategies (competitors, stress-tolerators and ruderals) to explain plant invasion across a broad elevation gradient. Accounting for phylogenetic relatedness, we tested two hypotheses. First, whether IAS occupy a different CSR space compared to native species. Second, whether the success of IAS at the regional scale is linked to higher degree of C- and/or R-selection, according to recent worldwide observations on naturalization success of alien species. We tested such hypotheses on different growth forms (trees, shrubs, long-lived herbs, short-lived herbs, hydrophytes) that are related to plant functional traits. Except for trees, IAS and native plant species essentially occupied the same CSR space, indicating that IAS can occupy the same niches of native species. However, IAS exhibited mainly higher C- scores compared to natives, suggesting that IAS are more competitive and are associated with relatively productive habitats, involving that these sites are highly prone to invasion (and that native species in resource-poor habitats are less likely to experience pressure from IAS). Our findings confirm the utility of CSR classification to broadly represent, and explain, the invasion success of alien plant species at the regional scale. This approach emerges as a viable tool in assessment of IAS characteristics and for development of strategies and plans for their containment. [ABSTRACT FROM AUTHOR]