AimThe influence of soil properties on photosynthetic traits in higher plants is poorly quantified in comparison with that of climate. We address this situation by quantifying the unique and joint contributions to global leaf-trait variation from soils and climate.Location Terrestrial ecosystems world-wide.Methods Using a trait dataset comprising 1509 species from 288 sites, with climate and soil data derived from global datasets, we quantified the effects of 20 soil and 26 climate variables on light-saturated photosynthetic rate (Aarea), stomatal conductance (gs), leaf nitrogen and phosphorus (Narea and Parea) and specific leaf area (SLA) using mixed regression models and multivariate analyses.Results Soil variables were stronger predictors of leaf traits than climatic variables, except for SLA. On average, Narea, Parea and Aarea increased and SLA decreased with increasing soil pH and with increasing site aridity. gs declined and Parea increased with soil available P (Pavail). Narea was unrelated to total soil N. Joint effects of soil and climate dominated over their unique effects on Narea and Parea, while unique effects of soils dominated for Aarea and gs. Path analysis indicated that variation in Aarea reflected the combined independent influences of Narea and gs, the former promoted by high pH and aridity and the latter by low Pavail.Main conclusions Three environmental variables were key for explaining variation in leaf traits: soil pH and Pavail, and the climatic moisture index (the ratio of precipitation to potential evapotranspiration). Although the reliability of global soil datasets lags behind that of climate datasets, our results nonetheless provide compelling evidence that both can be jointly used in broad-scale analyses, and that effects uniquely attributable to soil properties are important determinants of leaf photosynthetic traits and rates. A significant future challenge is to better disentangle the covarying physiological, ecological and evolutionary mechanisms that underpin trait-environment relationships.

Climate has experienced strong changes on time scales from decades to millions of years. As biodiversity has evolved under these circumstances, dependence on these climate dynamics is expected. Here, we assess the current state of knowledge on paleoclimatic legacies in biodiversity and ecosystem patterns. Paleoclimate have had strong impacts on past biodiversity dynamics, driving range shifts, extinctions, as well as diversification. We outline theory for how these dynamics may have left legacies in contemporary patterns and review the empirical evidence. We report ample evidence that Quaternary glacial-interglacial climate change affects current patterns in species distributions and diversity across a broad range of organisms and regions, with emerging evidence also for legacies of deeper-time paleoclimate and in patterns in phylogenetic and functional diversity and ecosystem functioning. Finally, we discuss implications for Anthropocene ecology and outline an agenda to improve our understanding of paleoclimate's role in shaping contemporary biodiversity and ecosystems.

Summary 1.A prevalent question in the study of plant invasions has been whether or not invasions can be explained on the basis of traits. Despite many attempts, a synthetic view of multi-trait differences between alien and native species is not yet available. 2. We compiled a database of three ecologically important traits (specific leaf area, typical maximum canopy height, individual seed mass) for 4473 species sampled over 95 communities (3784 species measured in their native range, 689 species in their introduced range, 207 in both ranges). 3. Considering each trait separately, co-occurring native and alien species significantly differed in their traits. These differences, although modest, were expressed in a combined 15% higher specific leaf area, 16% lower canopy height and 26% smaller seeds. 4. Using three novel multi-trait metrics of functional diversity, aliens showed significantly smaller trait ranges, larger divergences and a consistent differentiation from the median trait combination of co-occurring natives. 5. We conclude that the simultaneous evaluation of multiple traits is an important novel direction in understanding invasion success. Our results support the phenotypic divergence hypothesis that predicts functional trait differences contribute to the success of alien species.

14The 'home-field advantage (HFA) hypothesis' predicts that plant litter is decomposed faster than 15 expected in the vicinity of the plant where it originates from (i.e., its 'home') relative to some other 16 location (i.e., 'away') because of the presence of specialized decomposers. quality traits, and the dissimilarity between 'home' and 'away' of both the quality of reciprocally 22 exchanged litters and plant community type. Our results confirmed the occurrence of an overall, 23 worldwide, HFA effect on decomposition with on average 7.5% faster decomposition at home. However, 24there was considerable variation in the strength and direction (sometimes opposite to expectations) of 25 these effects. While macroclimate and average litter quality had weak or no impact on HFA effects, 26 home-field effects became stronger (regardless of the direction) when the quality of 'home' and 'away' 27 litters became more dissimilar (e.g. had a greater dissimilarity in N:P ratio; F 1,42 = 6.39, P = 0.015). 28

We estimated the latitudinal velocity (km/decade) of northern and southern boundaries of core distributions for 30 woody taxa over the last 16 000 years (biotic velocities) using networks of fossil pollen records, and compared these with climate velocities estimated from CCSM3 simulations. Biotic velocities were faster during periods of rapid temperature change (i.e. 16 to 7 ka) than times of relative stability (i.e. 7 to 1 ka), with a consistent northward movement of northern and southern boundaries. For most taxa, biotic velocities were faster for northern than for southern boundaries between 12 and 7 ka, resulting in expanding distributions. For individual time periods, biotic velocities were as fast or faster than climate velocities calculated using multivariate approaches. These results indicate that climate change paced the rate of distribution shifts in both northern and southern populations while suggesting that northern populations were more sensitive. A similar sensitivity and pacing is expected under 21st century climate change.

When taxa go extinct, unique evolutionary history is lost. If extinction is selective, and the intrinsic vulnerabilities of taxa show phylogenetic signal, more evolutionary history may be lost than expected under random extinction. Under what conditions this occurs is insufficiently known. We show that late Cenozoic climate change induced phylogenetically selective regional extinction of northern temperate trees because of phylogenetic signal in cold tolerance, leading to significantly and substantially larger than random losses of phylogenetic diversity (PD). The surviving floras in regions that experienced stronger extinction are phylogenetically more clustered, indicating that non-random losses of PD are of increasing concern with increasing extinction severity. Using simulations, we show that a simple threshold model of survival given a physiological trait with phylogenetic signal reproduces our findings. Our results send a strong warning that we may expect future assemblages to be phylogenetically and possibly functionally depauperate if anthropogenic climate change affects taxa similarly.

The coupling between community composition and climate change spans a gradient from no lags to strong lags. The no-lag hypothesis is the foundation of many ecophysiological models, correlative species distribution modelling and climate reconstruction approaches. Simple lag hypotheses have become prominent in disequilibrium ecology, proposing that communities track climate change following a fixed function or with a time delay. However, more complex dynamics are possible and may lead to memory effects and alternate unstable states. We develop graphical and analytic methods for assessing these scenarios and show that these dynamics can appear in even simple models. The overall implications are that (1) complex community dynamics may be common and (2) detailed knowledge of past climate change and community states will often be necessary yet sometimes insufficient to make predictions of a community's future state.

Summary1. Plant traits vary widely across species and underpin differences in ecological strategy. Despite centuries of interest, the contributions of different evolutionary lineages to modern-day functional diversity remain poorly quantified. 2. Expanding data bases of plant traits plus rapidly improving phylogenies enable for the first time a data-driven global picture of plant functional diversity across the major clades of higher plants. We mapped five key traits relevant to metabolism, resource competition and reproductive strategy onto a phylogeny across 48324 vascular plant species world-wide, along with climate and biogeographic data. Using a novel metric, we test whether major plant lineages are functionally distinctive. We then highlight the trait-lineage combinations that are most functionally distinctive within the present-day spread of ecological strategies. 3. For some trait-clade combinations, knowing the clade of a species conveys little information to neo-and palaeo-ecologists. In other trait-clade combinations, the clade identity can be highly revealing, especially informative clade-trait combinations include Proteaceae, which is highly distinctive, representing the global slow extreme of the leaf economic spectrum. Magnoliidae and Rosidae contribute large leaf sizes and seed masses and have distinctively warm, wet climatic distributions.