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What confers invasive alien plants a competitive advantage over native plants remains open to debate. Many of the world’s worst invasive alien plants are clonal and able to share resources within clones (clonal integration), particularly in heterogeneous environments. Here, we tested the hypothesis that clonal integration benefits invasive clonal plants more than natives and thus confers invasives a competitive advantage. Weselected five congeneric and naturally co-occurring pairs of invasive alien and native clonal plants in China, and grew pairs of connected and disconnected ramets under heterogeneous light, soil nutrient and water conditions that are commonly encountered by alien plants during their invasion into new areas. Clonal integration increased biomass of all plants in all three heterogeneous resource environments. However, invasive plants benefited more from clonal integration than natives. Consequently, invasive plants produced more biomass than natives. Our results indicate that clonal integration may confer invasive alien clonal plants a competitive advantage over natives. Therefore, differences in the ability of clonal integration could potentially explain, at least partly, the invasion success of alien clonal plants in areas where resources are heterogeneously distributed.

AIM: Despite the accumulation of cases describing fast radiations of alpine plants, we still have limited understanding of the drivers of speciation in alpine floras and of the precise the timing of their diversification. Here, we investigated spatial and temporal patterns of speciation in three groups of alpine Primulaceae. LOCATION: Mountains of the European Alpine System. METHODS: We built a new phylogeny of Primulaceae including all species in three focal groups: Androsace sect. Aretia, Primula sect. Auricula and Soldanella. Combining phylogenetic information with a detailed climatic data set, we investigated patterns of range and ecological overlap between sister‐species using an approach that takes phylogenetic uncertainty into account. Finally, we investigated temporal trajectories of diversification in the three focal groups. RESULTS: We found that a large majority of sister‐species pairs in the three groups are strictly allopatric and show little differences in substrate and climatic preferences, a result that was robust to phylogenetic uncertainty. While rates of diversification have remained constant in Soldanella, both Androsace sect. Aretia and Primula sect. Auricula showed decreased diversification rates in the Pleistocene compared to previous geological epochs. MAIN CONCLUSIONS: Allopatric speciation with little niche divergence appears to have been by far the most common mode of speciation across the three groups studied. A few examples, however, suggest that ecological and polyploid speciation might also have played a role in the diversification of these three groups. Finally, extensive diversification likely occurred in the late Miocene and Pliocene coinciding with the later phases of the Alpine uplift, while diversification slowed down during subsequent glacial cycles of the Pleistocene.

Aims: Although the impacts of alien plant invasions on native communities are well documented, the mechanisms that underlie these impacts are poorly resolved. Little is yet known as to why invasive alien plants have greater impacts than native species on their neighbouring species within a community. We investigated two potential mechanisms by which invasive plants may harm neighbouring species: resource competition and novel compounds of the invaders. Locations: Field removal experiment in France and Switzerland, and common garden experiment at the University of Fribourg, Switzerland. Methods: We first conducted a field removal experiment to compare the response of neighbouring communities to experimental biomass removal of two alien invasive vs two dominant native plant species in two sites of each target species (thus eight sites in total). In addition, we conducted a common garden pot experiment to compare the effect of eight triplets of closely related target species (24 species in total), each consisting of an alien invasive species in Europe, a dominant native and a random native species, on the growth of a grass community under the addition or not of activated carbon (AC). Results: (1) Field removal experiment: in the control plots, we found that the biomass of native species explained a substantial amount of the variation in biomass of the neighbouring communities, but the invader's biomass did not. Moreover, the neighbouring community recovered from removal of the dominant native species, showing a significant increase in biomass, but did not after removal of the invaders. (2) Common garden pot experiment: we found a larger effect of invasive species than native species on the growth rate of the grass community, but this difference disappeared when AC was added. Conclusion: Both experiments suggest that the impact of some invasive species is not driven by resource competition, but by other mechanisms, most likely by novel weapons or novel plant–soil interactions.

Aim Biological invasions threaten biodiversity globally. Large‐scale studies of non‐native plant species invasiveness typically focus on identifying ecological differences between naturalized and invasive species that account for their spread from sites of initial establishment (i.e., invasion success). However, invasive species differ widely in the magnitude of their impacts, suggesting the characteristics that favour invasion success might not necessarily predict the consequences of that invasion. Here we test whether those factors that increase the probability of plant species invasion also explain the severity of impacts. Location China. Methods We compiled a database of the invasiveness, biogeographic origins, life history traits, and introduction history for 538 non‐native plants in China and modelled differences in (a) naturalized and invasive species; (b) the spatial extent of invasion; and, (c) the severity of invasion impacts among successful invaders. Results Invasion success and the spatial extent of invasion shared similar influencing factors. However, these clearly differed from the predictors of severe invasion impacts. Unintentionally introduced non‐native plants with shorter life cycles and longer residence times were more likely to become invasive and to invade a larger area, while taller plants introduced from the Americas tended to have more severe impacts on the native ecosystems of China. Main Conclusions These results illustrate the different roles of introduction history, biogeographical origin and biological traits in determining the invasion success and spatial extent of invasion versus the severity of invasive species impacts. We suggest that factors associated with evolutionary adaptation and population expansion might determine invasion success and extent, while traits related to the relative competitive ability of invasive species determine the severity of impacts. Identifying specific characteristics of species that distinguish among successful invaders most likely to result in more severe impacts could help with planning more effective interventions.

Comparing the functional traits of co‐occurring native and invasive plant species can offer insight regarding mechanisms of invasion. Previous studies have failed to reach a consensus, indicating that the extent of trait differences between native and invasives might depend on the environmental context and on the spatial grain of the analysis. Here we evaluate the scale‐dependency of native–invader trait comparisons within the Hawaiian Archipelago, a globally important region of high endemicity and high invasibility. We evaluated trait (e.g. gas exchange, leaf nutrient concentration, specific leaf area) differences locally and regionally (i.e. within and across islands) and found that while invasives are more resource acquisitive at the regional scale, native–invader differences are highly idiosyncratic at localized scales, varying both in direction and magnitude within islands. Our findings clarify how region‐wide species comparisons may fail to characterize interactions happening at local scales, thereby misleading or obscuring the mechanisms underlying invasion.

Throughout evolution, living organisms have honed the ability to swiftly recognize biological motion (BM) across species. However, how the brain processes within‐ and cross‐species BM, and the evolutionary progression of these processes, remain unclear. To investigate these questions, the current study examined brain activity in the lateral temporal areas of humans and monkeys as they passively observed upright and inverted human and macaque BM stimuli. In humans, the middle temporal area (hMT+) responded to both human and macaque BM stimuli, while the right posterior superior temporal sulcus (hpSTS) exhibited selective responses to human BM stimuli. This selectivity is evidenced by an increased feedforward connection from hMT+ to hpSTS during the processing of human BM stimuli. In monkeys, the MT region processed BM stimuli from both species, but no subregion in the STS anterior to MT is specific to conspecific BM stimuli. A comparison of these findings suggests that upstream brain regions (i.e., MT) may retain homologous functions across species, while downstream brain regions (i.e., STS) may have undergone differentiation and specialization throughout evolution. These results provide insights into the commonalities and differences in the specialized visual pathway engaged in processing within‐ and cross‐species BMs, as well as their functional divergence during evolution. Cross‐species fMRI studies reveal distinct neural mechanisms for biological motion (BM) processing. In humans, the posterior superior temporal sulcus (hpSTS) selectively responds to conspecific BM, while monkeys process BM from both species in the middle temporal area (MT). This suggests conserved MT functions but specialized STS evolution, highlighting species‐specific adaptations in visual pathways for BM recognition.

Aim Why are some species geographically restricted? Ecological explanations suggest that endemic species may have restricted distributions because limited phenotypic variability results in narrow niches. However, studying variability of traits independently may not fully explain the interactions within and between complex phenotypes and environments. Here, we hypothesize that endemic species are restricted to a narrow range of habitats due to strong phenotypic integration (i.e. strong correlations among traits), strong environmental integration (i.e. strong correlations among the environments occupied) and strong correlations among trait-environment combinations. Location The Kerguelen Islands, sub-Antarctic. Methods We measured flowering phenology, multiple morphological characters, and species distribution along three abiotic environmental gradients (elevation, soil moisture and soil salinity) in 14 plant species whose distributions range from strictly endemic to cosmopolitan. Results We found that for individual species, trait means and variances were independent of endemism, but that endemics occupied higher and less variable microhabitats. However, phenotypic integration, environmental integration along the three gradients, and the strength of trait-environment correlations all increased with the level of species endemism. Main conclusions Higher levels of integration within and between phenotypes and environments are associated with more restricted geographical ranges in the species studied. In endemic species phenotypic integration may explain range contraction during the taxon cycle and reduce the ability to adapt to novel microhabitats formed as a result of environmental change.

Methylation of cytosines is a prototypic epigenetic modification of the DNA. It has been implicated in various regulatory mechanisms across the animal kingdom and particularly in vertebrates. We mapped DNA methylation in 580 animal species (535 vertebrates, 45 invertebrates), resulting in 2443 genome-scale DNA methylation profiles of multiple organs. Bioinformatic analysis of this large dataset quantified the association of DNA methylation with the underlying genomic DNA sequence throughout vertebrate evolution. We observed a broadly conserved link with two major transitions—once in the first vertebrates and again with the emergence of reptiles. Cross-species comparisons focusing on individual organs supported a deeply conserved association of DNA methylation with tissue type, and cross-mapping analysis of DNA methylation at gene promoters revealed evolutionary changes for orthologous genes. In summary, this study establishes a large resource of vertebrate and invertebrate DNA methylomes, it showcases the power of reference-free epigenome analysis in species for which no reference genomes are available, and it contributes an epigenetic perspective to the study of vertebrate evolution.

Background and aims Soil heterogeneity can be caused by plant-soil feedback (PSF), but little is known about how this affects plant growth and the distribution of roots. Moreover, as invasive and native plant species frequently differ in PSF and root-foraging ability, they may differ in their responses to PSF-mediated soil heterogeneity. Methods We first conditioned soils by 16 plant species (eight confamilial pairs of invasive alien and native species). Then, we grew each species in a homogeneous treatment with unconditioned soil and in three heterogeneous treatments with four patches. In the home-soil treatment, we filled two patches with unconditioned soil and two with soil conditioned by the target species. In the foreign-soil treatment, we filled two patches with unconditioned soil and two with soil conditioned by the other species in a pair. In the home-and-foreign-soil treatment, we filled two patches with home soil and two with foreign soil. Results Compared to the homogeneous unconditioned soil treatment, PSF negatively affected plant growth. In the heterogeneous treatment with control- and home-soil patches, biomass was reduced more strongly for the invasive species than for the native species. In the heterogeneous treatment with both home- and foreign-soil patches, root biomass of the invasive species was greater in the foreign-soil than in the home-soil patches, whereas the reverse was true for natives. Conclusion Although invasive species suffered more from conspecific PSF, root foraging allowed them to avoid home soil. In the long term, this could help invasive species gain a competitive advantage over natives.