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Transgenerational plasticity is a form of non-genetic inheritance that can reduce or enhance offspring fitness depending on parental stress. Yet, the adaptive value of such parental environmental effects and whether their expression varies among populations remain largely unknown. We used self-fertilized lines from climatically distinct populations of the crop wild relative Lupinus angustifolius. In the parental generation, full-siblings were grown in two contrasting watering environments. Then, to robustly separate the within-generation and transgenerational response to drought, we reciprocally assigned the offspring of parents to the same experimental treatments. We measured key functional traits and assessed lifetime reproductive fitness. Offspring of drought-stressed parents produced less reproductive biomass, but a similar number of lighter seeds, in dry soil compared to offspring of genetically identical, well-watered parents, an effect not mediated by differences in seed provisioning. Importantly, while the offspring of parents grown in the favourable environment responded to drought by slightly increasing individual seed mass, the pattern of plasticity of the offspring of drought-grown parents showed the opposite direction, and the negative effects of parental drought on seed mass were more pronounced in populations from cooler and moist habitats. Overall, our results show that parental effects may override immediate adaptive responses to drought and provide evidence of population-level variation in the expression of transgenerational plasticity.

PREMISE: Gypsum soils in the Mediterranean Basin house large numbers of edaphic specialists that are adapted to stressful environments. The evolutionary history and standing genetic variation of these taxa have been influenced by the geological and paleoclimatic complexity of this area and the long-standing effect of human activities. However, little is known about the origin of Mediterranean gypsophiles and the factors affecting their genetic diversity and population structure. METHODS: Using phylogenetic and phylogeographic approaches based on microsatellites and sequence data from nuclear and chloroplast regions, we evaluated the divergence time, genetic diversity, and population structure of 27 different populations of the widespread Iberian gypsophile Lepidium subulatum throughout its entire geographic range. RESULTS: Lepidium subulatum diverged from its nearest relatives ~3 million years ago, and ITS and psbA/matK trees supported the monophyly of the species. These results suggest that both geological and climatic changes in the region around the Plio-Pleistocene promoted its origin, compared to other evolutionary processes. We found high genetic diversity in both nuclear and chloroplast markers, but a greater population structure in the chloroplast data. These results suggest that while seed dispersal is limited, pollen flow may be favored by the presence of numerous habitat patches that enhance the movement of pollinators. CONCLUSIONS: Despite being an edaphic endemic, L. subulatum possesses high genetic diversity probably related to its relatively old age and high population sizes across its range. Our study highlights the value of using different markers to fully understand the phylogeographic history of plant species.

The ecological study of root systems lags behind the understanding of the aboveground components of plant communities, mainly due to methodological challenges. As ecological root theory develops complexity, root investigation methods are required to meet higher standards of quantitative and detailed data. Spatial root density distribution of plants represents one of the main features pursued in ecological studies, as it provides insight into root foraging behavior and belowground competition. To study root density, ecologists should preferably use and develop methods with the potential to provide the most comprehensive information: Individual Root Density Distribution (IRDD), i.e. individual-level and spatially-explicit root density maps. Here, we review the existing methods to detect roots in the field (detection methods), and to infer the identity of these roots (identification methods). We discuss potential combinations of Detection and Identification (DI) methods, and the data quality that these combinations yield in respect to IRDD. We anticipate that root field ecologists progressively may want to adopt DI methods showing the highest potential to provide high-quality IRDD. These methods are (i) ground-penetrating radar or acoustic tomography in combination with tracking the roots to the individual plant (i.e. skeleton method sensu lato), (ii) soil sampling in combination with in situ root staining (for physiological individuals), or (iii) soil sampling in combination with DNA microsatellites or single nucleotide polymorphism sequencing (for genetic individuals).

An unresolved question in plant ecology is whether diversity of the aboveground and belowground compartments of a plant community is similar at different neighbourhood scales. We investigated how the similarity between both compartments varies with the aboveground sampling grain and if significant discrepancies exist between aboveground and belowground plant diversity at the maximum similarity scale. We fully mapped the aboveground perennial plant community of a 64 m2 plot in a Mediterranean shrubland and analysed this compartment by assessing diversity in 5 to 50 cm radii circles centred in soil cores. We sampled 2.5 cm radius root cores at two different depths and identified plant species by using DNA metabarcoding to characterise the belowground compartment. We quantified differences in species richness, composition and species’ spatial distribution above- and belowground. The differences between aboveground and belowground communities were affected by the size of the aboveground sampling grain and were minimised when considering a circle of 20 cm radius in the aboveground. We found a significant dissimilarity in richness and composition between the two compartments, with larger differences when considering the deeper soil layer only. Our results showed that the spatial grain selected to sample a plant community aboveground and belowground is critical to characterise them in a comparable manner. Although their composition is related, species distribution patterns strongly differ, suggesting the simultaneous action of different assembly mechanisms. Our results call for caution when studying community assembly considering only the standing vegetation, since total plant diversity can be underappreciated.

[Motivation] Trait variation within species can reveal plastic and/or genetic responses to environmental gradients, and may indicate where local adaptation has occurred. Here, we present a dataset of rangewide variation in leaf traits from seven of the most ecologically and economically important tree species in Europe. Sample collection and trait assessment are embedded in the GenTree project (EU-Horizon 2020), which aims at characterizing the genetic and phenotypic variability of forest tree species to optimize the management and sustainable use of forest genetic resources. Our dataset captures substantial intra- and interspecific leaf phenotypic variability, and provides valuable information for studying the relationship between ecosystem functioning and trait variability of individuals, and the response and resilience of species to environmental changes., [Main types of variable contained] We chose morphological and chemical characters linked to trade-offs between acquisition and conservation of resources and water use, namely specific leaf area, leaf size, carbon and nitrogen content and their ratio, and the isotopic signature of stable isotope 13C and 15N in leaves., [Spatial location and grain] We surveyed between 18 and 22 populations per species, 141 in total, across Europe., [Time period] Leaf sampling took place between 2016 and 2017., [Major taxa and level of measurement] We sampled at least 25 individuals in each population, 3,569 trees in total, and measured traits in 35,755 leaves from seven European tree species, i.e. the conifers Picea abies, Pinus pinaster and Pinus sylvestris, and the broadleaves Betula pendula, Fagus sylvatica, Populus nigra and Quercus petraea., [Software format] The data files are in ASCII text, tab delimited, not compressed., All authors acknowledge support from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 676876 (Project GenTree). Laboratory work was also supported by other projects: COMEDIAS (CGL2017- 83170-R, Spanish Ministry of Science, Innovation and Universities), REMEDINAL IV (TE-CM S2018/EMT-4338, Project of the Autonomous Community of Madrid, Spain), SPONFOREST (BIODIVERSA-3, PCIN-2016-055), and International Laboratory of Global Change (LINCGlobal 4540-143AP). The Swiss contribution was supported by the Swiss Secretariat for Education, Research and Innovation (SERI) under contract no. 6.0032. BC was funded by a Scholarship from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES (Brazil).

In temperate forests, ectomycorrhizal fungi (EMF) form the dominant mycorrhizal symbiotic association. EMF increase root uptake of nutrients and water in exchange for carbohydrates. The composition, structure and abundance of EMF communities are shaped by abiotic factors such as soil water availability, chemical and physical properties. Biotic factors also play a strong role especially tree species identity and plant physiological activity. Water availability affects both biotic and abiotic factors and thus is a major driver of EMF community structure and function. Under current climate change scenarios, seasonal drought risk is predicted to expand into areas where ecosystems may not be adapted to limited water availability. This is the case of European beech (Fagus sylvatica) forests growing along their southern distribution limit, in the Iberian Peninsula. Here, we characterized the abundance and composition of the EMF community and the patterns of root water uptake, in forests along a precipitation gradient (2500, 1100 and 900 mm/year), in northern Spain. We sampled soil, wood and fine roots in three mature pure beech forests at two times during the growing season, with contrasting soil water availabilities. DNA was extracted from EMF tips for molecular analyses (DNA meta-barcoding) to estimate species richness and diversity for each site and sampling campaign. Root colonization by EMF decreased in the late part of the growing season, when soil water availability was lower and this decline was larger at the rainiest site. We found that EMF species richness and diversity were similar across sites and sampling campaigns, irrespective of soil water availability. Yet, across sites, EMF communities were distinctly separated in the multidimensional space and did not change over the season, suggesting that EMF communities would be adapted to the local climatic and abiotic conditions. Analyses of water isotopic composition showed that root water uptake relied on upper soil moisture at the rainiest site, whereas it relied on deeper water reservoirs at the sites with more limiting water availability. Taken together our results suggest that EMF communities of F. sylvatica forests along their southern distribution limit would be adapted to low seasonal water availability, provided that trees had access to deep soil water. Also, at sites where water availability was more limiting, roots would take up water from deeper soil horizons, whereas nutrients and EMF would still concentrate in the shallower soil layers, which could suggest a spatial decoupling between nutrient and water uptake. Meanwhile, at sites with abundant rainfall, both nutrient and water uptake would be strongly linked to water availability in the upper soil and thus these functions could be potentially more vulnerable to changes in precipitation patterns, mainly increased frequency and duration of rainless periods.

Roots are assumed to play a major role in structuring soil microbial communities, but most studies exploring the relationships between microbes and plants at the community level have only used aboveground plant distribution as a proxy. However, a decoupling between belowground and aboveground plant components may occur due to differential spreading of plant canopies and root systems. Thus, soil microbe–plant links are not completely understood. Using a combination of DNA metabarcoding and spatially explicit sampling at the plant neighbourhood scale, we assessed the influence of the plant root community on soil bacterial and fungal diversity (species richness, composition and b-diversity) in a dry Mediterranean scrubland. We found that root composition and biomass, but not richness, predict unique fractions of variation in microbial richness and composition. Moreover, bacterial b-diversity was related to root b-diversity, while fungal b-diversity was related to aboveground plant b-diversity, suggesting that plants differently influence both microbial groups. Our study highlights the role of plant distribution both belowground and aboveground, soil properties and other spatially structured factors in explaining the heterogeneity in soil microbial diversity. These results also show that incorporating data on both plant community compartments will further our understanding of the relationships between soil microbial and plant communities.

Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

14Pág. Centro de Investigación Forestal (CIFOR), Natural selection is the major force driving adaptive evolution in natural populations, varying in strength, direction, and form through space and time, especially in highly variable environments such as Mediterranean ecosystems. Although a conservative resource-use strategy has been hypothesized to be adaptive in Mediterranean taxa, patterns of selection at the intraspecific level, that is, the suite of traits determining individual fitness, are largely unknown. Using a phenotypic selection experiment in natural semi-arid conditions, we measured direct and indirect selection acting through two different fitness components (survival and reproduction), to assess the adaptive value of 20 ecophysiological traits on individuals of two gypsum endemic species, Centaurea hyssopifolia and Helianthemum squamatum, dwelling in environments with contrasting abiotic conditions (south- and north-facing slopes) during two climatically contrasting years (dry and mesic). This allowed quantifying the magnitude and direction of natural selection at different spatiotemporal scales. Our results revealed that different abiotic conditions did not alter selection patterns, being the magnitude of selection more strongly affected by temporal environmental variation. Selection through reproduction indicated consistent selection for early phenology, low water use efficiency, high specific leaf area, low leaf dry matter content, and high leaf N across slopes and years in both species. In contrast, phenotypic trait variation was not linked to survival in either species. Furthermore, while individual reproductive output was higher or similar in environments with higher abiotic stress in both species and years, survival was similar across environmental conditions, and it was neither affected by plant size nor reproductive output. Contrary to our expectations, natural selection via reproductive fitness consistently favoured a drought-escape, acquisitive resource-use strategy in Mediterranean semi-arid plants, rather than a conservative resource-use strategy, even under conditions of higher abiotic stress (i.e. south slopes and dry year). Such acquisitive strategy could allow rapid development by maximizing resource assimilation and reproduction before the most limiting climatic conditions of mid-late summer. Our results shed light on adaptive functional strategies of Mediterranean taxa at the intraspecific level, providing insight on future responses to environmental change, and highlight remarkable differences in selection acting through different fitness components. Read the free Plain Language Summary for this article on the Journal blog., This study was funded by the Spanish Ministerio de Economía y Competitividad (grant GYPSEVOL, CGL2016-75566-P) and the Madrid Regional Government (grant Remedinal3-CM, S2013/MAE-2719). We thank C. Díaz for his assistance during trait measurements, and R. Milla and T.E. Gimeno for their inspiring ideas during the discussion process and insightful comments on the manuscript.

Plant trait- based ecology is a powerful extension of the attempt of community ecolo -gists to unveil assembly mechanisms. However, the two main expected determinants of community assembly, niche and neutral processes, can be confused under this framework. Here, we propose to move from trait- based to phenotype- based commu-nity ecology, accounting for the variation between individuals (phenotypes affected by the abiotic and biotic environment, and vice versa), and explicitly considering their ability to compete with or facilitate its neighbours. This would shift our focus from species’ niche responses to niche specialization of phenotypes, reducing the space for neutrality at the finest scales. The current assembly framework, based mainly on niche complementarity and using species-average functional traits, has been devel -oped exploring mega- diverse communities, but it fails at describing poor plant com -munities. Under this framework, monospecificity would be interpreted as an arena where functionally similar individuals compete, consequently leading to regular pat -terns, which are rarely found in nature. Our niche specialization framework could help explaining coexistence in rich plant communities, where the higher fraction of functional variation is found between species, whereas the intraspecific trait varia -tion dominates in poor species and monospecific communities. We propose a guide to conduct massive phenotyping at the community scale based on the use of visible and near- infrared spectroscopy. We also discuss the need to integrate the so- called plant's eye perspective based on the use of spatial pattern statistics in the current community ecology toolbox., This work was supported by the Ministerio de Economía y Competitividad of the Spanish Government [PHENOTYPES PGC2018-099115-B-I00] and by Comunidad de Madrid Government [REMEDINAL-TE- CM P2018/EMT-4338].

Most work on plant community ecology has been performed above ground, neglecting the processes that occur in the soil. DNA metabarcoding, in which multiple species are computationally identified in bulk samples, can help to overcome the logistical limitations involved in sampling plant communities belowground. However, a major limitation of this methodology is the quantification of species’ abundances based on the percentage of sequences assigned to each taxon. Using root tissues of five dominant species in a semi‐arid Mediterranean shrubland (Bupleurum fruticescens, Helianthemum cinereum, Linum suffruticosum, Stipa pennata and Thymus vulgaris), we built pairwise mixtures of relative abundance (20%, 50% and 80% biomass), and implemented two methods (linear model fits and correction indices) to improve estimates of root biomass. We validated both methods with multispecies mixtures that simulate field‐collected samples. For all species, we found a positive and highly significant relationship between the percentage of sequences and biomass in the mixtures (R2 = .44–.66), but the equations for each species (slope and intercept) differed among them, and two species were consistently over‐ and under‐estimated. The correction indices greatly improved the estimates of biomass percentage for all five species in the multispecies mixtures, and reduced the overall error from 17% to 6%. Our results show that, through the use of post‐sequencing quantification methods on mock communities, DNA metabarcoding can be effectively used to determine not only species’ presence but also their relative abundance in field samples of root mixtures. Importantly, knowledge of these aspects will allow us to study key, yet poorly understood, belowground processes.

Matesanz, S., Ramos-Munoz, M., Blanco-Sanchez, M., Garcia-Fernandez, A., Escudero, A. 2019. Migration, genetic variation and phenotypic plasticity of gypsophiles and their role on climate change responses. Ecosistemas 28(1): 48-59. Doi.: 10.7818/ECOS.1525 Gypsum habitats host unique plant communities due to their high richness and abundance of endemic species. Although our knowledge regarding several aspects of their ecology has increased over the last decades, the effects of climate change on gypsophiles, and importantly, their response mechanisms, have been poorly explored. Under the increased aridity foreseen for many regions due to climate change, plants may migrate to more favorable sites, adapt to new environmental conditions or adjust via phenotypic plasticity. In this study, we review the documented effects of climate change on gypsophile populations and evaluate the existing evidence on their potential responses. Despite the stress-tolerant nature of these species, several studies have shown negative effects on their physiology, phenology and demography. Several aspects related to life on gypsum, including natural and anthropogenic fragmentation, gypsophily and lack of active dispersal mechanisms may greatly limit their migration ability. Although there is very little information in population differentiation, evolutionary potential for key functional traits and phenotypic plasticity, our revision suggests that these mechanisms will have a more prominent role than migration in a climate change context. Therefore, we propose future research lines to allow a deeper knowledge on microevolutionary process involved in the response of gypsophiles to climate change.

Understanding constraints to phenotypic plasticity is key given its role on the response of organisms to environmental change. It has been suggested that phenotypic integration, the structure of trait covariation, could limit trait plasticity. However, the relationship between plasticity and integration is far from resolved. Using a database of functional plasticity to drought of a Mediterranean shrub that included 20 ecophysiological traits, we assessed environmentally-induced changes in phenotypic integration and whether integration constrained the expression of plasticity, accounting for thewithin-environment phenotypic variation of traits. Furthermore, we provide the first test of the association between differential trait plasticity and trait integration across an optimumand a stressful environment. Phenotypic plasticity was positively associated with phenotypic integration in both environments, but this relationship was lost when phenotypic variation was considered. The similarityin the plastic response of two traits predicted their integration across environments, with integrated traits having more similar plasticity. Such variation in the plasticity of traits partly explained the lower phenotypic integration found in the stressful environment. We found no evidence that integration may constitute an internal constraint to plasticity. Rather, we present the first empirical demonstration that differences in plastic responses mayinvolve a major reorganization of the relationships among traits, and challenge the notion thatstress generally induces a tighter phenotype., This work was funded by grants GYPSEVOL (CGL2016-75566-P), Remedinal (TE-CM: S2018/EMT-4338), Phenotypes (PGC2018-099115-B-I00) and the Ramon y Cajal Programme of the Spanish Ministry of Economy and Competitiveness.

1. Plant species that grow across environmental gradients show a range of trait ex-pression, but traits do not vary independently. In fact, phenotypes are integrated expressions of multiple traits that covary due to trade-offs among functions and processes. Understanding trait covariation structures will ultimately help with predicting species' responses to change and developing management actions., 2. We measured variation and covariation (a proxy of phenotypic integration) among functional traits of Pinus sylvestris from paired populations across its European distribution. Populations within a pair were close enough to be in gene flow con-tact but located in contrasting environmental conditions across a local gradient. Measured traits represented three axes of variation (groups of traits) related to a tree's competitive ability and the trade-off between resource acquisition and conservation, namely plant size measures and stem and foliar traits., 3. Results revealed important intra- and inter-population trait variability. In particular, at the population level, trait means shifted across the climatic gradient mainly de-scribed by mean annual temperature. Moreover, we found a higher degree of trait covariation in populations under harsher environments (i.e. lower environmental suitability for the species). This pattern was consistent within population pairs, suggesting that higher trait covariation may be adaptive, being more coordinated in sites with harsher conditions. At larger spatial scales, we found a less conclusive pattern with a trend of increasing covariation at the northern edge of the species distribution. This result suggests that at larger scales different processes may be in-volved in the trade-off between the adaptive value of phenotypic covariation ver-sus its constraints on trait combinations that may limit plant's response capability., 4. Synthesis. Trait covariation varies at different spatial scales, increasing under harsher conditions, and the robustness and repeatability of this pattern suggests its adaptive role for the species' responses to different environments., Funding was provided by the European Union Horizon 2020 Project GenTree (Grant Agreement No. 676876). Extra support came from the Spanish projects REMEDINAL TE-CM (Autonomous Community of Madrid, S2018/EMT-4338), Phenotypes (PGC2018-099115-B-100), COMEDIAS (CGL2017-83170-R, Spanish Ministry of Science, Innovation and Universities), and Swiss Secretariat for Education, Research and Innovation (SERI) under contract No. 6.0032. R.B. is now funded by the Contrato-Programa CEEC Individual, Fundação para a Ciência e Tecnologia, Portugal. B.C. was funded by CAPES fellowship (DOC-PLENO -Programa de Doutorado Pleno no Exterior. Grant Agreement No. 99999.001266/2015-02, Brazil). C.C.B. was supported by a post-doctoral fellowship of the Ramón Areces Foundation.

[Questions]: While positive effects of tree diversity on tree community biomass have often been reported in mature stands, the debate on whether diversity effects may be detectable at the seedling level persists, with opposing outcomes found so far. We still lack a comprehensive evaluation of the biodiversity effects (so- called ‘comple-mentarity’ and ‘selection’ effects), as well as the phenotypic drivers at play, underly-ing early-community biomass. Even less is known about whether such biodiversity effects may change under water- limited conditions., [Location]: Seeds from four tree species coexisting in a Mediterranean forest (Spain)., [Methods]: We built experimental tree seedling assemblages with three diversity lev-els — monocultures, two- species and four- species mixtures — and under two soil moisture conditions. We quantified the extent to which species richness, species identity, community-weighted mean (CWM) and functional dissimilarity (FD) influ-ence complementarity and selection effects. We computed CWM and FD for seven functional traits related to water and light acquisition; and we calculated the comple-mentarity and selection effects from above- and below- ground biomass measures at the community level., [Results]: Our results showed that complementarity drove the greater biomass in more diverse assemblages at the seedling stage. This pattern was largely favored by a par-ticular species, Quercus faginea, with distinct phenotypic traits (great height, lateral ramification and root biomass with high dry matter content), which induced a positive effect of CWM on community biomass. Moreover, our study showed that the water deficit limited the production of above- ground biomass without interacting with the community’s species richness., [Conclusion]: Our study provides evidence that positive biodiversity effects on com-munity biomass occur early, at the seedling stage, and it highlights the essential role that certain tree species play from their initial development stages by favoring spatresource partitioning. Our work motivates future studies to apply integrated ap-proaches in assessing both the community-wide and species-specific effects to understand the biodiversity–biomass relationship., This work was supported by the Spanish-funded project REMEDINAL-3CM (S2013/MAE-2719). CCB is supported by a postdoctoral fellowship of the Ramón Areces Foundation. BC thanks Coordenação de Aperfeiçoamento de Pessoal de Níıvel Superior - CAPES [DOC- PLENO - Programa de Doutorado Pleno no Exterior (grant Agreement No 99999.001266/2015-02) for a research scholarship. CV was supported by the European Research Council (ERC) Starting Grant Project ‘Ecophysiological and Biophysical Constraints on Domestication in Crop Plants’ (grant ERC- StG -2014- 639706-CONSTRAINTS).

The effects of habitat fragmentation on plant populations are complex, as it might disrupt many ecological processes, including plant reproduction and plant-animal interactions. Gypsum specialist plants may be resilient to fragmentation due to their evolutionary history in fragmented landscapes, but the effects on non-specialist plants occurring in gypsum are unknown. We conducted a study focusing on different aspects of the reproductive cycle of Astragalus incanus subsp. incanus, a plant facultatively linked to gypsum soils. We focused on plant fecundity and pre-dispersal predation, obtained from field observations, and offspring performance, assessed in a common garden. Beyond fragment size and connectivity, we also considered habitat quality, population size and density and plant size as predictors. Fragment size and connectivity had no effect on plant fecundity, but jointly determined fruit predation, while fragment size was positively related to offspring growth. Population density, rather than population size, had a positive effect on predation but negatively affected plant fecundity and offspring performance. Habitat quality reduced both plant fecundity and predation incidence. In this non-specialist species, habitat fragmentation, population features and habitat quality affect different facets of plant performance. Predation was the only process clearly affected by fragmentation variables, fecundity mainly depended on population features and offspring performance and was better explained by mother plant identity. Our results show the need to consider habitat and population features together with fragment size and connectivity in order to assess the effects of fragmentation. Importantly, these effects can involve different aspects of plant reproduction, including plant-animal interactions.

The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios., Measurement(s)growth ring • wood densityTechnology Type(s)measuring table • calculationFactor Type(s)tree speciesSample Characteristic - OrganismBetula pendula • Fagus sylvatica • Picea abies • Populus nigra • Pinus pinaster • Pinus sylvestris • Quercus petraeaSample Characteristic - LocationEurope Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11294993

Populations of widely distributed species often exhibit geographic variation in functional traits in response to environmental heterogeneity. Such trait variation may be the result of different adaptive mechanisms, including genetically based differentiation, phenotypic plasticity or a combination of both. Disentangling the genetic and environmental components of trait variation may be particularly interesting in crop wild relatives, since they may provide unique reservoirs of genetic diversity for crop improvement. In this study, we assessed ecotypic differentiation and patterns of plasticity to drought in populations of Lupinus angustifolius, a Mediterranean crop wild relative, from two climatically distinct regions in the Iberian Peninsula. Using an outdoor common garden, we compared phenotypic responses of inbred maternal families to two ecologically meaningful water availability treatments (drought and high-moisture). We measured 18 different functional traits related to growth, morphology, phenology and reproduction. Plants in the drought treatment grew less, had lower leaf chlorophyll content and photochemical efficiency, but also reproduced faster, produced larger seeds and altered leaflet morphology through increased leaflet thickness, higher leaflet dry matter content and lower specific leaf area. We also found significant differences between regions that likely reflect adaptation to climatically distinct environments, with populations from the south showing a faster onset of reproduction, higher leaf thickness and higher seed size, consistent with the drier conditions experienced in southern sites. Plasticity to drought was in most cases in the same direction as quantitative genetic differentiation (i.e. cogradient variation), providing evidence of the adaptive value of the plastic change. Our results show that both genetic differentiation and plasticity can generate adaptive phenotypic variation in L. angustifolius, and help to identify potentially valuable genetic resources to incorporate into breeding programmes., We assessed adaptive differentiation and phenotypic plasticity in populations of Lupinus angustifolius, a Mediterranean crop wild relative, from two regions in the Iberian Peninsula. We compared how plants from different populations responded to two water availability treatments, drought and high-moisture, and measured several functional traits. Plants in the drought treatment reproduced faster, produced larger seeds and showed changes in leaf morphology, consistent with adaptive plasticity. Significant differences between regions likely reflect adaptation of the southern populations to their drier environment. We conclude that both genetic differentiation and plasticity can contribute to the adaptation of L. angustifolius to different water availability environments, and help to identify valuable genetic resources for breeding.

The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios. Measurement(s) growth ring • wood density Technology Type(s) measuring table • calculation Factor Type(s) tree species Sample Characteristic - Organism Betula pendula • Fagus sylvatica • Picea abies • Populus nigra • Pinus pinaster • Pinus sylvestris • Quercus petraea Sample Characteristic - Location Europe Published

Gypsum endemics occur in naturally-fragmented habitats, which may lead to genetic erosion and higher vulnerability to the genetic effects of anthropogenic fragmentation. Conversely, evolution in a fragmented landscape could increase their resilience to the effects of further fragmentation, but no evidence is available in either direction. In this study, we capitalize on previous results showing high genetic variation and a negative, yet small, effect of fragmentation on genetic variation on the gypsophile Lepidium subulatum, and jointly assess two other co-occurring dominant gypsophiles: Helianthemum squamatum and Centaurea hyssopifolia. We sampled individuals of the species in 20 populations varying in their fragment size and connectivity (≈400 plants/species; 1138 individuals total), and assessed genetic variation and population structure using species-specific microsatellite markers. Genetic variation was high in populations of the three study species, as shown by the high expected heterozygosity (0.454–0.735) and allelic richness (2.875–8.125). Population differentiation was in general low, but H. squamatum showed a stronger spatial structure than the other species. No effects of fragment size or connectivity were found for H. squamatum or C. hyssopifolia, i.e. differences among populations in genetic variation were not related to the size or connectivity of the sampled habitat remnants. These results contrast with the expectation that habitat specialists may be genetically impoverished. Furthermore, the correlation of key genetic diversity indices among species suggests that some fragments harbor more genetically-diverse populations than others, which provides insights for their conservation. We propose that these species may offset the genetic effects of human-mediated further habitat loss and increased isolation.

Crop domestication has resulted in relevant phenotypic divergences between crop plants and wild progenitors, but domestication effects on phenotypic plasticity are poorly known. We grew plants of domesticated and wild progenitor accessions of seven taxonomically-diverse crops in three experimental glasshouse treatments differing in soil water and nutrient availabilities, and measured growth, morphological and physiological traits that are key in plant responses to water and nutrient limitations. We compared growth performance, trait means, and norms of reaction between domestication statuses and crop species. Phenotypes were significantly affected by the experimental treatments. Under low water and low nutrient availabilities, plants decreased specific leaf area to produce smaller and thicker leaves, and decreased stomatal conductance. Plasticity to changes in water availability was more pronounced than to varying nutrient supply. Domesticated and wild accessions significantly differed in plasticity patterns to limiting water for several key traits (maximum height, total leaf area, plant-level photosynthetic rate and growth performance traits). Our results thus provide initial insight into generalized domestication effects on phenotypic plasticity. Importantly, crop plants outperformed wild plants in favorable conditions, but suffered a higher loss of performance under water stress, which contrasts with studies suggesting that selection for high performance in optimum conditions might also improve it in stressful environments. We propose that the greater phenotypic homeostasis of the wild progenitors may be a target for future breeding focused on selection for adaptive norms of reaction in heterogeneous environments.

© 2017 The Authors., The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species’ distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs. central), population size (large vs. small), and seed disperser (introduced carnivores vs. endemic lizards) on the genetic diversity and population structure of the species. Contrasting genetic variation (H: 0.04–0.476) was found across populations. Peripheral populations showed lower genetic diversity, but this was dependent on population size. Large peripheral populations showed high levels of genetic diversity, whereas small central populations were less diverse. Significant isolation by distance was detected, indicating that the effect of long-distance gene flow is limited relative to that of genetic drift, probably due to high selfing rates (F = 0.155–0.887), restricted pollen flow, and ineffective seed dispersal. Bayesian clustering also supported the strong population differentiation and highly fragmented structure. Contrary to expectations, the type of disperser showed no significant effect on either population genetic diversity or structure. Our results challenge the idea of an effect of periphery per se that can be mainly explained by population size, drawing attention to the need of integrative approaches considering different determinants of genetic variation. Furthermore, the very low genetic diversity observed in several small populations and the strong among-population differentiation highlight the conservation value of large populations throughout the species’ range, particularly in light of climate change and direct human threats., Funding was provided by the Spanish Ministry for Innovation and Science with the grants Consolider Montes (CSD2008_00040) and VULGLO (CGL2010‐22180‐C03‐03) provided to FV, and the Minsitry of Economy and Competitiveness, grant ECOMETAS (CGL2014‐53840‐REDT) and Junta de Andalucía Excellence project to Juan Arroyo and AT.

Summary Food security faces challenges that must be addressed from multiple perspectives. Ecology and agronomy contribute to that endeavour, allowing improvement in management practices. However, not only management affects food provision but also crop traits modulate key ecosystem services (ESs), including sustained yields. Here we highlight that understanding how crop traits evolved under domestication, affecting ESs delivery, should help to breed future crops. We address the effects of crop evolution (from initial domestication to current times) on crop traits and key ESs: crop yield and its stability over time, soil carbon sequestration, soil nitrogen retention and water provision. Synthesis. There is evidence that crop domestication affects the delivery of ESs. However, most of these evolutionary effects are understudied. Accordingly, we identify research gaps and necessary actions, including (i) assessing whether performance in polyculture is lower for modern crop mixtures than for mixtures of wild progenitors, and breeding for more efficient crop polycultures; and (ii) investigating how crop evolution impacted on plant effects on soil carbon sequestration and nitrogen retention, and how such effects contribute to yield stability. The provision of cropland ESs, and thus food security, will benefit from exploring those avenues from an ecological perspective.

Plant diversity fosters productivity in natural ecosystems. Biodiversity effects might increase agricultural yields at no cost in additional inputs. However, the effects of diversity on crop assemblages are inconsistent, probably because crops and wild plants differ in a range of traits relevant to plant–plant interactions. We tested whether domestication has changed the potential of crop mixtures to over‐yield by comparing the performance and traits of major crop species and those of their wild progenitors under varying levels of diversity. We found stronger biodiversity effects in mixtures of wild progenitors, due to larger selection effects. Variation in selection effects was partly explained by within‐mixture differences in leaf size. Our results indicate that domestication might disrupt the ability of crops to benefit from diverse neighbourhoods via reduced trait variance. These results highlight potential limitations of current crop mixtures to over‐yield and the potential of breeding to re‐establish variance and increase mixture performance.

The introduced Asian plant Polygonum cespitosum has only recently become invasive in northeastern North America, spreading into sunny as well as shaded habitats. We present findings from a multiyear case study of this ongoing species invasion, drawing on field environmental measurements, glasshouse plasticity and resurrection experiments, and molecular genetic (microsatellite) data. We focus in particular on patterns of individual phenotypic plasticity (norms of reaction), their diversity within and among populations in the species' introduced range, and their contribution to its potential to evolve even greater invasiveness. Genotypes from introduced-range P. cespitosum populations have recently evolved to express greater adaptive plasticity to full sun and/or dry conditions without any loss of fitness in shade. Evidently, this species may evolve the sort of "general-purpose genotypes" hypothesized by Herbert Baker to characterize an "ideal weed." Indeed, we identified certain genotypes capable of extremely high reproductive output across contrasting conditions, including sunny, shaded, moist, and dry. Populations containing these high-performance genotypes had consistently higher fitness in all glasshouse habitats; there was no evidence for local adaptive differentiation among populations from sunny, shaded, moist, or dry sites. Norm of reaction data may provide valuable insights to invasion biology: the presence of broadly adaptive, high-performance genotypes can promote a species' ecological spread while providing the fuel for increased invasiveness to evolve.

Advances in phenology and pole- and up-ward shifts in geographic ranges are well-documented signs that species are responding to climate change. A deeper understanding of such responses across ecologically different species groups will help to assess future consequences for entire ecosystems. A less well-studied pattern linked with climate change is increases in abundances of warm-adapted species compared with cold-adapted species. To compare how recent climate change has affected the abundances of species across different taxonomic groups, we analyzed long-term local population trends and related them to the species temperature niche, as inferred from geographic distributions. We used population data sets collected in different regions of Central Europe, primarily Germany, for bats, birds, butterflies, ground beetles, springtails and dry grassland plants. We found that temperature niche was positively associated with long-term population trends in some of the taxonomic groups (birds, butterflies, ground beetles) but was less important in others (bats, springtails, and grassland plants). This variation in the importance of temperature niche suggested that some populations have been affected more than others by climate change, which may be explained by differences in species attributes, such as generation time and microhabitat preference. Our findings indicate that relating temperature niches of species to population trends is a useful method to quantify the impact of climate change on local population abundances. We show that this widely applicable approach is particularly suited for comparative cross-system analyses to identify which types of organisms, in which habitats, are responding the most to climate change., OS also acknowledges support from the seventh European Commission Framework Programme (FP7) via the Integrated Project STEP (grant no. 244090) (Potts et al., 2011)., European Commission

Most habitat fragmentation studies have focused on the effects of population size on reproductive success of single species, but studies assessing the effects of both fragment size and connectivity, and their interaction, on several coexisting species are rare. In this study, we selected 20 fragments along two continuous gradients of size and degree of isolation in a gypsum landscape in central Spain. In each fragment, we selected 15 individuals of each of three dominant gypsophiles (Centaurea hyssopifolia, Lepidium subulatum and Helianthemum squamatum, 300 plants per species, 900 plants in total) and measured several reproductive traits: inflorescence number, fruit set, seed set and seed mass. We hypothesised that plant fitness would be lower on small and isolated fragments due to an interaction between fragment size and connectivity, and that response patterns would be species-specific. Overall, fragment size had very little effect on reproductive traits compared to that of connectivity. We observed a positive effect of fragment connectivity on C. hyssopifolia fitness, mediated by the increased seed predation in plants from isolated fragments, resulting in fewer viable seeds per capitulum and lower seed set. Furthermore, seed mass was lower in plants from isolated fragments for both C. hyssopifolia and L. subulatum. In contrast, few reproductive traits of H. squamatum were affected by habitat fragmentation. We discuss the implications of species-specific responses to habitat fragmentation for the dynamics and conservation of gypsum plant communities. Our results highlight the complex interplay among plants and their mutualistic and antagonistic visitors, and reinforce the often-neglected role of habitat connectivity as a key component of the fragmentation process.

1. Interannual variability in climatic conditions should be taken into account in climate change studies in semi-arid ecosystems. It may determine differentiation in phenotypic plasticity among populations, with populations experiencing higher environmental heterogeneity showing higher levels of plasticity., 2. The ability of populations to evolve key functional traits and plasticity may determine the survival of plant populations under the drier and more variable climate expected for semi-arid ecosystems., 3. Working with populations of the semi-arid Chilean shrub Senna candolleana along its entire distribution range, we assessed inter- and intra-population variation in functional traits as well as in their plasticity in response to water availability. We measured morphological and physiological traits related to drought resistance in both field conditions and in a greenhouse experiment, where drought response was evaluated under two water availability treatments., 4. All populations responded plastically, but higher precipitation heterogeneity in dry-edge populations seemed to have selected for more plastic genotypes compared to populations growing at mesic sites and with more homogeneous environmental conditions., 5. Synthesis. Our results suggest adaptive plasticity since higher levels of phenotypic plasticity were positively associated with plant performance. However, we did not find evidence for genetic variation for plasticity within populations. To the extent that phenotypic plasticity may play a key role in future persistence, populations at mesic sites may be more vulnerable to climate change due to their lower plasticity and their current limitations to evolve novel norms of reaction. Conversely, although Senna candolleana populations at the dry edge are exposed to higher levels of stress, they may be less susceptible to climate change in view of their greater plasticity. We highlight the need to consider population differentiation in both mean traits and their plasticity to model realistic scenarios of species distribution under climate change., Funding was provided by the Spanish Ministry for Innovation and Science with the grants Consolider Montes (CSD2008_00040) and VULGLO (CGL2010-22180-C03-03).

Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia, a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from ten populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although Centaurea hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population’s similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations’ survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness, our study highlights the need to shift the focus of fragmentation studies to the mechanisms that regulate connectivity effects, and call for caution on the use of genetic variation and plasticity to forecast population performance.

Climate change, land-use change, pollution and exploitation are among the main drivers of species' population trends; however, their relative importance is much debated. We used a unique collection of over 1,000 local population time series in 22 communities across terrestrial, freshwater and marine realms within central Europe to compare the impacts of long-term temperature change and other environmental drivers from 1980 onwards. To disentangle different drivers, we related species' population trends to species- and driver-specific attributes, such as temperature and habitat preference or pollution tolerance. We found a consistent impact of temperature change on the local abundances of terrestrial species. Populations of warm-dwelling species increased more than those of cold-dwelling species. In contrast, impacts of temperature change on aquatic species' abundances were variable. Effects of temperature preference were more consistent in terrestrial communities than effects of habitat preference, suggesting that the impacts of temperature change have become widespread for recent changes in abundance within many terrestrial communities of central Europe., Additionally, we appreciate the open access marine data provided by the International Council for the Exploration of the Sea. We thank the following scientists for taxonomic or technical advice: C. Brendel, T. Caprano, R. Claus, K. Desender, A. Flakus, P. R. Flakus, S. Fritz, E.-M. Gerstner, J.-P. Maelfait, E.-L. Neuschulz, S. Pauls, C. Printzen, I. Schmitt and H. Turin, and I. Bartomeus for comments on a previous version of the manuscript. R.A. was supported by the EUproject LIMNOTIP funded under the seventh European Commission Framework Programme (FP7) ERA-Net Scheme (Biodiversa, 01LC1207A) and the long-term ecological research program at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB). R.W.B. was supported by the Scottish Government Rural and Environment Science and Analytical Services Division (RESAS) through Theme 3 of their Strategic Research Programme. S.D. acknowledges support of the German Research Foundation DFG (grant DO 1880/1-1). S.S. acknowledges the support from the FP7 project EU BON (grant no. 308454). S.K., I.Kü. and O.S. acknowledge funding thorough the Helmholtz Association’s Programme Oriented Funding, Topic ‘Land use, biodiversity, and ecosystem services: Sustaining human livelihoods’. O.S. also acknowledges the support from FP7 via the Integrated Project STEP (grant no. 244090). D.E.B. was funded by a Landes–Offensive zur Entwicklung Wissenschaftlich–ökonomischer Exzellenz (LOEWE) excellence initiative of the Hessian Ministry for Science and the Arts and the German Research Foundation (DFG: Grant no. BO 1221/23-1).

Global change poses new challenges for plant species, including novel and complex combinations of environmental conditions to which plants should adjust and adapt. Mediterranean ecosystems are recognized biodiversity hotspots but are also global change hotspots due to the concerted action of multiple environmental drivers. In the face of these changes, Mediterranean plants can migrate to more suitable habitats, adapt through natural selection, adjust via phenotypic plasticity or go extinct. In this paper, we review responses of Mediterranean plants to global change, specifically focusing on plastic and microevolutionary responses to climate change, and common factors that affect and limit such responses, such as habitat fragmentation. The available evidence suggests that Mediterranean species can respond plastically to environmental change, but plasticity differs not only among species and populations but also among traits and environmental factors to which the plants are responding. Dry Mediterranean climates could limit the expression of plasticity in still uncertain ways. Although there is evidence for significant within-population evolutionary potential for functionally important traits in several Mediterranean species, little is known about whether this variation drives measurable evolutionary change. Habitat fragmentation exacerbates the negative impacts of climate change because it limits both the expression of plasticity and the evolutionary potential of plants. Invasive species, typically initiated as small populations in novel environments, provide important ecological and evolutionary insights on responses to global change that can foster specific research on Mediterranean plants. Our revision revealed that knowledge for Mediterranean plants is particularly scant on the constraints to plasticity, its adaptive value and its transgenerational potential, as well as on the fine-tuning of genetic change to environmental change. © 2013 Elsevier B.V., Financial support for writing this manuscript was provided by the grants Consolider Montes (CSD2008 00040) and VULGLO (CGL2010-22180-C03-03), and by the Community of Madrid grant REMEDINAL 2 (CM S2009/AMB-1783).

• Domestication might affect plant size. We investigated whether herbaceous crops are larger than their wild progenitors, and the traits that influence size variation. • We grew six crop plants and their wild progenitors under common garden conditions. We measured the aboveground biomass gain by individual plants during the vegetative stage. We then tested whether the photosynthesis rate, biomass allocation to leaves, leaf size, and specific leaf area (SLA) accounted for variations in whole-plant photosynthesis, and ultimately in aboveground biomass. • Despite variations among crops, domestication generally increased the aboveground biomass (average effect +1.38, Cohen's d effect size). Domesticated plants invested less in leaves and more in stems than their wild progenitors. Photosynthesis rates remained similar after domestication. Variations in whole-plant C gains could not be explained by changes in leaf photosynthesis. Leaves were larger after domestication, which made the main contribution to increases in the leaf area per plant and plant-level C gain, and ultimately to larger aboveground biomass. • In general, cultivated plants have become larger after domestication. In our six crops, this occurred despite lower investment in leaves, comparable leaf-level photosynthesis, and similar biomass costs of leaf area (i.e., SLA) than their wild progenitors. Greater leaf size was the main driver of increases in aboveground size. Thus, we suggest that large seeds, which are also typical of crops, might produce individuals with larger organs (i.e., leaves) via cascading effects throughout ontogeny. Larger leaves would then scale into larger whole plants, which might partly explain the increases in size that accompanied domestication. This article is protected by copyright. All rights reserved.

The amount of quantitative genetic variation within an invasive species influences its ability to adapt to conditions in the new range and its long-term persistence. Consequently, this aspect of genetic diversity (or evolutionary potential) can be a key factor in the success of species invasions. Previous studies have compared the evolutionary potential of populations in introduced versus native ranges of invasive species, but to date no study has examined differences among introduced-range populations of such species in levels of quantitative genetic variation expressed in ecologically relevant environments. We assessed quantitative variation of fitness, life-history, and functional traits in six geographically separate introduced-range populations of the invasive annual Polygonum cespitosum, by comparing norms of reaction for a large sample of genotypes (16–19 per population) expressed in response to two glasshouse environments simulating contrasting habitats in this new range. Patterns of reaction norm diversity varied considerably among the 6 populations studied. Two populations showed very little quantitative genetic variation in both environments. In contrast, two other populations contained significant genetic variation for fitness and life-history traits in the form of genotypes with low performance in both habitats. Finally, two populations showed significant norm of reaction diversity in the form of cross-over interaction: genotypes that performed relatively well in one environment did poorly in the other. Differences among populations in potential selective response are likely to affect the dynamics and future spread of P. cespitosum, since specific populations will likely contribute differently to the invasion process. More generally, our results suggest that the evolutionary component of long-term invasion success may depend on population rather than on species-level processes.

The spatial pattern of plant communities can be an indicator of the processes that regulate community structure and their interplay with environmental drivers such as climate. However, to exploit such indicators we need a fuller understanding of the links between spatial pattern and climate. We examined variation in spatial pattern of annuals/biennials and perennials in a range margin steppic plant community in Germany over 26 years. We assessed change in spatial pattern through time, and how this change was related to local variation in climate and community composition. We found increasing dissociation between annuals/biennials and perennials through time, and a response of spatial pattern to summer temperature and precipitation. These responses are associated with the occurrence of Centaurea stoebe, a species which establishes in the community mid-way through the recording period. Our results indicate that in some circumstances spatial patterning of vegetation may not be directly linked to environmental severity, and that species turnover rather than changes in the interactions or abundance of species already in the community can influence the observed dynamics of vegetation spatial pattern. Thus, they support calls for a better understanding of the context-specificity of plant–plant interactions, their translation to spatial pattern, and their regulation by climate and other drivers such as species turnover.

The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species’ distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs. central), population size (large vs. small), and seed disperser (introduced carnivores vs. endemic lizards) on the genetic diversity and population structure of the species. Contrasting genetic variation (H E: 0.04–0.476) was found across populations. Peripheral populations showed lower genetic diversity, but this was dependent on population size. Large peripheral populations showed high levels of genetic diversity, whereas small central populations were less diverse. Significant isolation by distance was detected, indicating that the effect of long‐distance gene flow is limited relative to that of genetic drift, probably due to high selfing rates (FIS = 0.155–0.887), restricted pollen flow, and ineffective seed dispersal. Bayesian clustering also supported the strong population differentiation and highly fragmented structure. Contrary to expectations, the type of disperser showed no significant effect on either population genetic diversity or structure. Our results challenge the idea of an effect of periphery per se that can be mainly explained by population size, drawing attention to the need of integrative approaches considering different determinants of genetic variation. Furthermore, the very low genetic diversity observed in several small populations and the strong among‐population differentiation highlight the conservation value of large populations throughout the species’ range, particularly in light of climate change and direct human threats.

Background and aims Plant-soil interactions are a crucial component of ecosystem functioning. However, most global change studies focus on plant communities, with information on soil properties and performance being scarce. Our goal was to assess the individual and joint effect of habitat heterogeneity and three global change drivers (fragmentation, loss of habitat quality and climate change) on nutrient availability and soil microbial activity in Mediterranean gypsum soils.

Global change drivers create new environmental scenarios and selective pressures, affecting plant species in various interacting ways. Plants respond with changes in phenology, physiology, and reproduction, with consequences for biotic interactions and community composition. We review information on phenotypic plasticity, a primary means by which plants cope with global change scenarios, recommending promising approaches for investigating the evolution of plasticity and describing constraints to its evolution. We discuss the important but largely ignored role of phenotypic plasticity in range shifts and review the extensive literature on invasive species as models of evolutionary change in novel environments. Plasticity can play a role both in the short-term response of plant populations to global change as well as in their long-term fate through the maintenance of genetic variation. In new environmental conditions, plasticity of certain functional traits may be beneficial (i.e., the plastic response is accompanied by a fitness advantage) and thus selected for. Plasticity can also be relevant in the establishment and persistence of plants in novel environments that are crucial for populations at the colonizing edge in range shifts induced by climate change. Experimental studies show taxonomically widespread plastic responses to global change drivers in many functional traits, though there is a lack of empirical support for many theoretical models on the evolution of phenotypic plasticity. Future studies should assess the adaptive value and evolutionary potential of plasticity under complex, realistic global change scenarios. Promising tools include resurrection protocols and artificial selection experiments.

Plant populations are subjected to changes in their natural environment as a result of the incidence of simultaneous global change drivers. Despite the fact that these changes can largely affect early fitness components, information on the effects of simultaneous drivers of global change on offspring traits and performance is particularly scant. We analyzed the combined effect of three global change drivers of critical importance in Mediterranean ecosystems (habitat fragmentation, reductions in habitat quality and water availability) on germination and seedling performance of the gypsophile shrub Centaurea hyssopifolia. Seedlings from 39 mother plants from eight different environments (resulting from the combination of the three global change drivers) were sown and grown in a common garden. First, germination percentage, seedling size and seedling survival were monitored. Secondly, seedling performance and ecophysiological traits were measured under well and low-watered conditions. Fragmentation showed the largest negative effect on germination and offspring performance. Seedlings of mothers from small fragments germinated more slowly, showed lower survival, died faster, and showed lower photosynthetic rates under well-watered conditions compared to seedlings of mother plants from large populations. Seedlings of different maternal origins did not differ in their response to water stress or in their ability to survive to drought. Ninety-five percent of the seedlings survived until soil water content was as low as 3%. Our study shows that global change can have not only immediate impacts on plant populations but also transgenerational effects, and highlights the importance of studies involving multiple drivers and a more integral understanding of global change.

Meta-analysis(MA)isapowerfultoolforrevealinggeneraltrends and quantitatively synthesizing the results of inde-pendent studies. Nevertheless, the procedure has beencriticized, particularly when it has been applied to eco-logical and conservation biology studies.To provide an updated picture of the effect of forestmanagement on biodiversity, we performed an MA with

We compared physiological and morphological traits of Thymus loscosii, a rare endemic of semiarid Spain, and Thymus vulgaris, a widespread Mediterranean species, over a precipitation gradient, and measured the spatial patterns of both species. Our results do not provide evidence for a congruent suite of traits associated with rarity in T. loscosii, since this species showed some traits reported in rare species (lower height and biomass), but exhibited better performance under severe climatic conditions (higher photochemical efficiency and quantum yield during winter) and higher values of traits conferring competitive abilities (SLA and LAR). T. loscosii did not show either lower phenotypic variability or better performance than its congener along the precipitation gradient. The two thymes were spatially dissociated when they co-occurred and the spatial pattern of T. loscosii changed from clumped in the presence of its congener to random when it was the only thyme, suggesting competition between the two species. These results suggest that T. loscosii is not a habitat-specialist and may behave as a refuge endemic. Its reduced distribution may be linked to a limited competitive ability that is not associated with the vegetative traits explored, although other causes like habitat degradation and genetic or reproductive constraints might also be important to explain its limited distribution. Biología y Geología

Questions: (1) Is climate a strong driver of vegetation dynamics, including interannual variation, in a range margin steppic community? (2) Are there long-term trends in cover and species richness in this community, and are these consistent across species groups and species within groups? (3) Can long-term trends in plant community data be related to variation in local climate over the last three decades?