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Global interest and investment in nature‐based solutions (NbS) are rapidly increasing because of the potential of this approach to concurrently counter biodiversity loss, provide cost‐effective measures for climate change adaptations, and maintain natural processes that underpin human health and wellbeing.Recognition is growing that grasslands in many regions will protect carbon stores more effectively than forests in the warmer, drier, more fire‐prone conditions of the future while also serving as hotspots for biodiversity. Yet grasslands have received less attention for their NbS potential. Despite the wide‐ranging goals of this approach, many investments in nature‐based solutions also have focused narrowly on using plants to meet climate pledges, often without considering plant interactions with herbivores and the abiotic environment that jointly control ecosystem functioning and underpin the success of nature‐based solutions.Here, we review the roles that large and small vertebrate and invertebrate herbivores play in the ability of the world's grasslands to provide nature‐based solutions, with a focus on wild herbivore impacts on biodiversity and carbon storage.Synthesis. Planning for nature‐based solutions with a holistic, ecologically informed view that includes the role of herbivores and their interaction with plants and the environment will allow NbS investments to more likely achieve successful, sustainable outcomes. [ABSTRACT FROM AUTHOR]

Summary: Local adaptation to contrasting environmental conditions along environmental gradients is a widespread phenomenon in plant populations, yet we lack a mechanistic understanding of how individual agents of selection contribute to this evolutionary process.Here, we developed a novel evolutionary functional–structural plant (E‐FSP) model that recreates local adaptation of virtual plants along an environmental gradient. First, we validate the model by testing if it can reproduce two elevational ecotypes of Dianthus carthusianorum occurring in the Swiss Alps. Second, we use the E‐FSP model to disentangle the relative contribution of abiotic (temperature) and biotic (competition and pollination) selection pressures to elevational adaptation in D. carthusianorum.Our results suggest that elevational adaptation in D. carthusianorum is predominantly driven by the abiotic environment. The model reproduced the qualitative differences between the elevational ecotypes in two phenological (germination and flowering time) and one morphological trait (stalk height), as well as qualitative differences in four performance variables that emerge from G × E interactions (flowering time, number of stalks, rosette area and seed production).Our approach shows how E‐FSP models incorporating physiological, ecological and evolutionary mechanisms can be used in combination with experiments to examine hypotheses about patterns of adaptation observed in the field. [ABSTRACT FROM AUTHOR]

Animal signals are dynamic traits that can undergo considerable spatial and temporal changes and that are influenced by factors such as age, health condition and interactions with both the abiotic and biotic environment. However, much of our understanding of signal changes throughout an individual's lifetime stems from cross‐sectional, often laboratory‐based, studies focused on visual and auditory signals. Longitudinal field investigations of temporal variation in chemical signals, especially in vertebrates, remain rare despite chemical communication being the most ubiquitous form of information exchange in the natural world. To remedy this, we conducted a unique, replicated field experiment to study the temporal signal dynamics in free‐living lizard populations on natural islands. Specifically, we collected scent marks from individually marked lizards across five populations during the spring of two consecutive years and analysed the lipophilic chemical composition of these scent marks. Our findings demonstrate that the overall scent mark composition of individual lizards changed over time, shifting consistently in both direction and magnitude from year to year among individuals and across replicate populations. Similar patterns were observed for the chemical richness and diversity of scent marks. Temporal variation in the relative proportions of three potentially socially relevant signalling compounds in lizard scent marks revealed a more complex pattern: α‐tocopherol remained stable over time, oleic acid decreased and the change in octadecanoic acid proportion was body size‐dependent. Together, our results provide novel insights into how individual vertebrate chemical signals may fluctuate across space and time. We discuss the potential causes of the observed temporal variability and its consequences for chemical signal evolution. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Colonisation of novel habitats are important events in evolution, but the factors that initially prompt such ecological transitions are often unknown. The invasion of land by fish is an extreme habitat transition that offers an opportunity to empirically investigate the causes of major ecological transitions. The intertidal ecotone—and rock pools in particular—have been an important staging ground for transitions onto land. Classic hypotheses focus on the adverse abiotic conditions of rock pools at low tide as the instigator of fish voluntarily stranding themselves out of water, which can then lead to the evolution of an amphibious lifestyle. To test these hypotheses, we studied the abiotic conditions of 54 rock pools on the island of Guam where there are various species of aquatic, amphibious and terrestrial blenny fishes. We found little support for the expected deterioration of abiotic conditions in standing pools at low tide (salinity, pH and oxygen), and fish were not seen to be excluded from those pools that were found to exhibit poor abiotic conditions (temperature, salinity and pH). Hypoxia was the only factor that might account for the absence of blennies from certain rock pools. Next, we experimentally measured oxygen depletion by an aquatic, mildly amphibious and highly amphibious species of blenny found on Guam in a simulated rockpool to infer the proportion of rock pools at low tide outside the tolerable range of blennies. Rock pools were found to have oxygen levels within the requirements of most blennies and those of other marine fishes reported in the literature. We conclude that the abiotic environment of rock pools alone was unlikely to have instigated the evolution of amphibious behaviour in blennies, at least on Guam. Instead, the broad range of abiotic conditions experienced in rock pools suggests these conditions could have primed amphibious blennies to better endure the novel conditions on land. Any ecotone typified by fluctuations or gradients in abiotic conditions is likely a key transitional environment for the invasion of novel habitats and, as such, are an important location for adaptive evolution and species diversification. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The proportion of people living in urban areas is growing globally. Understanding how to manage urban biodiversity, ecosystem functions, and ecosystem services is becoming more important. Biodiversity can increase ecosystem functioning in non‐urban systems. However, few studies have reviewed the relationship between biodiversity and ecosystem functioning in urban areas, which differ in species compositions, abiotic environments, food webs, and turnover rates. We reviewed evidence of biodiversity–ecosystem functioning relationships in urban environments and assessed factors that influence the relationship direction. Based on 70 studies, relationships between biodiversity and ecosystem functioning were more positive than negative in urban areas, especially for pollination and nutrient cycling and retention. Surprisingly, positive and negative relationships between biodiversity and biomass production and storage were equally not statistically different, perhaps due to extensive plant management in urban areas. The number of studies and geographic coverage of our review was still insufficient to provide a general predictive framework for when biodiversity positively impacts ecosystem functioning. We identify gaps and opportunities to improve urban biodiversity–ecosystem functioning research and discuss how our findings can improve urban green space management. [ABSTRACT FROM AUTHOR]

Summary: Understanding how widespread species adapt to variation in abiotic conditions across their ranges is fundamental to ecology. Insight may come from studying how among‐population variation (APV) in the common garden corresponds with the environmental conditions of source populations. However, there are no such studies comparing native vs non‐native populations across multiple life stages.We examined APV in the performance and functional traits of 59 Conyza canadensis populations, in response to drought, across large aridity gradients in the native (North America) and non‐native (Eurasia) ranges in three experiments. Our treatment (dry vs wet) was applied at the recruitment, juvenile, and adult life stages.We found contrasting patterns of APV in drought responses between the two ranges. In the native range, plant performance was less reduced by drought in populations from xeric than mesic habitats, but such relationship was not apparent for non‐native populations. These range‐specific patterns were consistent across the life stages.The weak adaptive responses of non‐native populations indicate that they can become highly abundant even without complete local adaptation to abiotic environments and suggest that long‐established invaders may still be evolving to the abiotic environment. These findings may explain lag times in invasions and raise concern about future expansions. [ABSTRACT FROM AUTHOR]

To maximize their fitness, plants have to adjust their allocation strategy according to their abiotic and biotic environments. Plants can use the ratio of red to far‐red light (R:FR) to sense neighbours, allowing them to modify their growth in response to aboveground competition.In this study, we used supplemental FR light to artificially lower the R:FR of the lower leaves of common sunflowers (Helianthus annuus) to examine how plants change their growth in response to the threat of neighbours. We combined this treatment with a nitrogen fertilization treatment to investigate how responses to neighbour‐detection interact with nitrogen limitation.Plants grown in low R:FR increased in height at the expense of root growth, resulting in nitrogen limitation that restricted leaf growth. However, we found that plants reduced their nitrogen investment into leaves in low R:FR. By weakening the nitrogen sink strength of these lower leaves before they experienced low photosynthetically active radiation, plants were able to preemptively allocate nitrogen to leaves higher in the canopy.Plants responded to the perception of neighbours by simultaneously diverting resources from root growth to stem elongation and from leaves threatened by neighbours to leaves that would pose a threat to neighbours. This whole‐plant response to neighbour‐detection enables plants to change their allocation in a way that simultaneously manages their limited nitrogen and prepares them for future light competition. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Freshwater megafauna, such as sturgeons, giant catfishes, river dolphins, hippopotami, crocodylians, large turtles, and giant salamanders, have experienced severe population declines and range contractions worldwide. Although there is an increasing number of studies investigating the causes of megafauna losses in fresh waters, little attention has been paid to synthesising the impacts of megafauna on the abiotic environment and other organisms in freshwater ecosystems, and hence the consequences of losing these species. This limited understanding may impede the development of policies and actions for their conservation and restoration. In this review, we synthesise how megafauna shape ecological processes in freshwater ecosystems and discuss their potential for enhancing ecosystem restoration. Through activities such as movement, burrowing, and dam and nest building, megafauna have a profound influence on the extent of water bodies, flow dynamics, and the physical structure of shorelines and substrata, increasing habitat heterogeneity. They enhance nutrient cycling within fresh waters, and cross‐ecosystem flows of material, through foraging and reproduction activities. Freshwater megafauna are highly connected to other freshwater organisms via direct consumption of species at different trophic levels, indirect trophic cascades, and through their influence on habitat structure. The literature documenting the ecological impacts of freshwater megafauna is not evenly distributed among species, regions, and types of ecological impacts, with a lack of quantitative evidence for large fish, crocodylians, and turtles in the Global South and their impacts on nutrient flows and food‐web structure. In addition, population decline, range contraction, and the loss of large individuals have reduced the extent and magnitude of megafaunal impacts in freshwater ecosystems, rendering a posteriori evaluation more difficult. We propose that reinstating freshwater megafauna populations holds the potential for restoring key ecological processes such as disturbances, trophic cascades, and species dispersal, which will, in turn, promote overall biodiversity and enhance nature's contributions to people. Challenges for restoration actions include the shifting baseline syndrome, potential human–megafauna competition for habitats and resources, damage to property, and risk to human life. The current lack of historical baselines for natural distributions and population sizes of freshwater megafauna, their life history, trophic interactions with other freshwater species, and interactions with humans necessitates further investigation. Addressing these knowledge gaps will improve our understanding of the ecological roles of freshwater megafauna and support their full potential for facilitating the development of effective conservation and restoration strategies to achieve the coexistence of humans and megafauna. [ABSTRACT FROM AUTHOR]

Natural selection on traits expressed repeatedly by individuals is usually investigated with a focus on mean values, although within‐individual trait distributions often differ also in other aspects, such as their spread and shape. In plants producing multiple flowers during a season, there might not be a single optimal flowering time, but rather an optimal distribution of flower opening dates. This optimal distribution might depend on both resource allocation patterns and interactions with the abiotic and biotic environment. In this study, we quantified mean, variance, skewness and kurtosis of 495 individual flowering schedules (5287 flowers) over 3 years, and assessed phenotypic selection on these aspects of the within‐individual distribution of opening dates in the perennial herb Lathyrus vernus. We also explored how selection on within‐individual variation in flowering schedules was related to effects on two fitness components: fruit set and the proportion of seeds escaping pre‐dispersal predation. Within‐individual variation in phenology was larger than, or at least similar to, among‐individual variation in all years. We found phenotypic selection on several aspects of individual flowering schedules. In 1 year, selection favoured plants with higher variance in opening dates, and this coincided with a higher fruit set in plants with an increased spread of the flowering schedule. In two of the study years, selection favoured a higher asymmetry of the flowering schedule, and plants with more right‐skewed distributions had higher fruit set and higher proportions of seeds escaping predation. Both fruit set and seed predation increased with an earlier mean flowering, resulting in no net selection on mean flowering date. Synthesis: Our results suggest that phenotypic selection on the spread and shape of flower opening date distributions might be at least as important as selection on the mean flowering date. In a broad sense, this implies that we should consider the entire trait distribution if we aim to understand the evolution of traits that are expressed multiple times within individuals. [ABSTRACT FROM AUTHOR]

The abiotic environment exerts strong effects on plant‐associated microbes, shaping their interactions with plants and resulting ecosystem processes. However, these abiotic effects on plant–microbe interactions are often highly specific and contingent on the abiotic driver or microbial group, requiring synthesis work describing general patterns and from this generate hypotheses and guide mechanistic work. To address this, we conducted a meta‐analysis of the effects of climate change‐related abiotic factors, namely warming, drought, and eCO2, on plant‐associated microbes distinguishing by microbial taxonomic or biological group (bacteria, fungi or virus) and the plant part where microbes are found or associated with (phyllosphere or rhizosphere). We found abiotic driver‐specific patterns, whereby drought significantly reduced microbial abundance, whereas warming and eCO2 had no significant effects. In addition, these abiotic effects were contingent on the microbial taxonomic group, with fungi being negatively affected by drought but positively affected by warming (eCO2 enrichment had no effect), whereas bacteria and viruses were not significantly affected by any factor. Likewise, rhizospheric microbes were negatively affected by drought but positively affected by warming (eCO2 enrichment had no effect), whereas phyllospheric microbes were not significantly affected by any factor. Collectively, these findings point to important implications for global change research by highlighting contrasting effects of climate change‐related abiotic drivers on plant‐associated microbes and the contingency of such effects on microbe life histories and the nature of their interactions with plants. [ABSTRACT FROM AUTHOR]

Duckweeds are a widely distributed and economically important aquatic plant family that have high potential for phytoremediation of polluted water bodies. We collected four ecotypes of the common duckweed Lemna minor from the four corners of Switzerland and assessed how their home versus away environments influenced their growth. Additionally, we investigated their response to a metal pollutant (zinc, Zn) in both their home and away environments. Zn is found in freshwater systems and can become harmful to plants at elevated concentrations. We hypothesized that growing in their home environment would help the plants buffer the negative effect of the metal pollutant. To test this, we measured Lemna growth in a common garden experiment in a glasshouse where the four ecotypes were grown in each of the water environments, as well as in three different concentrations of Zn. To investigate whether interactions between Lemna and its microbial community can enhance or reduce tolerance to heavy metal pollution, we sampled chlorophyll‐a as a proxy for algal biomass. Finally, we measured total nitrogen and total organic carbon to describe the abiotic environment in more detail. The four Lemna ecotypes exhibited significantly different growth rates across the water treatments. This difference in fitness was matched with DNA sequencing revealing genetic differentiation between the four ecotypes. However, the effect of the water and Zn treatment on Lemna growth was the same for all ecotypes. We did not find evidence for local adaptation; instead, we observed strong plastic responses. Lemna growth rates were higher under higher Zn concentrations. This positive effect of Zn on Lemna growth could be in part due to reduced competition with algae. We conclude that L. minor ecotypes may exhibit large differences in growth rate, but that the species overall has a high Zn tolerance and strong plastic adaptive potential in novel environments. [ABSTRACT FROM AUTHOR]

Mycoheterotrophy, whereby plants acquire both carbon and nutrients from a fungal partner, is an evolutionarily puzzling phenomenon. According to biological market models, mycoheterotrophs have nothing to offer and thus should be shunned as trading partners by discriminating fungi. Nevertheless, mycoheterotrophy is common, particularly among orchids, and an estimated 10% of all plant species are facultatively mycoheterotrophic at early stages in their life cycle. Reconciling mycoheterotrophy with biological market models, I describe how mycoheterotrophs could use arbitrage trading to net a profit of carbon and nutrients, without acquiring either from the abiotic environment. The model requires that mycoheterotrophs simultaneously buy and sell both carbon and nutrients, exploiting variability in the trading ratios offered by mycorrhizal fungi. The model relies on several conditions, including the ability of the mycoheterotroph to form indirect hyphal associations with two or more neighbouring autotrophic mycorrhizal associations, the existence of variable carbon:nutrient exchange ratios among these associations and the ability of mycoheterotrophs to invert the net‐direction of resource trade. Evidence that these conditions occur in a state of nature varies from incontrovertible to plausible given available models. The arbitrage model provides evolutionary rationale for mycoheterotrophy from both the plant and fungal perspective. Accordingly, mycoheterotrophs match trading ratios offered by autotrophic plants and, thus, need not be antagonists. The model makes novel predictions that distinguish it from source‐sink models, most notably in the existence of resource exchange inversions at the plant‐mycorrhizal interface. Finally, the model emphasizes market inefficiencies as the foundation on which mycoheterotrophs construct an arbitrage niche. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This article discusses the role of environmental factors in shaping the plant microbiome, specifically focusing on the influence of bacterial and fungal communities on plant responses to water stress. The article highlights recent studies that examine the impact of different genotypes and levels of water stress on bacterial communities in quinoa plants and the relationship between environmental factors and fungal communities in apple fruit. The findings emphasize the importance of understanding plant microbiome dynamics for developing effective crop protection strategies and improving agricultural sustainability. The article suggests that microbiome-based strategies, which manipulate the plant microbiome, offer promising approaches for addressing crop productivity challenges while minimizing the use of harmful chemicals. [Extracted from the article]

Interspecific competition can hinder populations from evolutionarily adapting to abiotic environments, particularly by reducing population size and niche space; and feedback may arise between competitive ability and evolutionary adaptation. Here we studied populations of two model bacterial species, Escherichia coli and Pseudomonas fluorescens, that evolved in monocultures and cocultures for approximately 2400 generations at three temperatures. The two species showed a reversal in competitive dominance in cocultures along the temperature gradient. Populations from cocultures where they had been competitively dominant showed the same magnitude of fitness gain as those in monocultures. However, competitively inferior populations in cocultures showed limited abiotic adaptation compared with those in monocultures. The inferior populations in cocultures were also more likely to evolve weaker interspecific competitive ability, or go extinct. The possible competitive ability‐adaptation feedback may have crucial consequences for population persistence. [ABSTRACT FROM AUTHOR]

Introduced plants create lasting abiotic and biotic changes to soil that are increasingly implicated as major drivers of invasion success, yet models for investigating patterns in the impacts of these soil legacies are lacking. Here, we used Bohemian knotweed (Reynoutria × bohemica) to present a novel approach for testing whether accounting for diverse evolutionary drivers can clarify how an invader's soil legacy mediates its success. For most tested species, R. × bohemica's soil legacy did not influence seedling performance irrespective of its evolutionary history or the evolutionary novelty of species that share its soil. However, we found the relative importance of legacy effects versus other mechanisms of invader dominance depends on the life stage of the plants growing in soil conditioned by the invader. While the effects of R. × bohemica's soil legacy on seedling performance were context dependent, emergence was, on average, higher in R. × bohemica‐conditioned soils than in unconditioned soils. Thus, contrary to theory, R. × bohemica's soil legacy not only fails to impede potential competitors but may also facilitate them. Our results are particularly powerful: we detected novel insights in the face of biological complexity, even for R. × bohemica, which likely does not depend on heterospecific plant–soil feedbacks for its competitive dominance in its introduced range. Designing rigorous investigations that explore how plant species' evolutionary histories mediate an invader's soil legacy across diverse abiotic environments, as shown here, is key for producing insights in other systems. [ABSTRACT FROM AUTHOR]

The speed of population adaptation to changing biotic and abiotic environments is determined by the interaction between genetic drift, positive selection and linkage effects. Many marine species (fish, crustaceans), invertebrates and pathogens of humans and crops, exhibit sweepstakes reproduction characterized by the production of a very large amount of offspring (fecundity phase) from which only a small fraction may survive to the next generation (viability phase). Using stochastic simulations, we investigate whether the occurrence of sweepstakes reproduction affects the efficiency of a positively selected unlinked locus, and thus, the speed of adaptation since fecundity and/or viability have distinguishable consequences on mutation rate, probability and fixation time of advantageous alleles. We observe that the mean number of mutations at the next generation is always the function of the population size, but the variance increases with stronger sweepstakes reproduction when mutations occur in the parents. On the one hand, stronger sweepstakes reproduction magnifies the effect of genetic drift thus increasing the probability of fixation of neutral allele and decreasing that of selected alleles. On the other hand, the time to fixation of advantageous (as well as neutral) alleles is shortened by stronger sweepstakes reproduction. Importantly, fecundity and viability selection exhibit different probabilities and times to fixation of advantageous alleles under intermediate and weak sweepstakes reproduction. Finally, alleles under both strong fecundity and viability selection display a synergistic efficiency of selection. We conclude that measuring and modelling accurately fecundity and/or viability selection are crucial to predict the adaptive potential of species with sweepstakes reproduction. [ABSTRACT FROM AUTHOR]

Plant species respond to varying plant species diversity and associated changes in their abiotic and biotic environment with changes in their phenotype. However, it is not clear to what degree this phenotypic differentiation is due to genotype diversity within populations or phenotypic plasticity of plant individuals. We studied individuals of 16 populations of the clonal herb Taraxacum officinale grown in plant communities of different species richness in a 17‐year‐old grassland biodiversity experiment (Jena Experiment). We collected 12 individuals in each population to measure phenotypic traits and identify distinct genotypes using microsatellite DNA markers. Plant species richness did not influence population‐level genotype and trait diversity. However, it affected the expression of several phenotypic traits, e.g. leaf and inflorescence number, maximum leaf length and seed mass, which increased with increasing plant species richness. Moreover, population‐level trait diversity correlated positively with genotype richness for leaf dry matter content (LDMC) and negatively with inflorescence number. For several traits (i.e. seed mass, germination rate, LDMC, specific leaf area (SLA)), a larger portion of variance was explained by genotype identity, while variance in other traits (i.e. number of inflorescences, leaf nitrogen concentration, leaf number, leaf length) resided within genotypes and thus was mostly due to phenotypic plasticity. Overall, our findings show that plant species richness positively affected the population means of some traits related to whole‐plant performance, whose variation was achieved through both phenotypic plasticity and genotype composition of a population. [ABSTRACT FROM AUTHOR]

Understanding how tropical forests respond to abiotic environmental changes is critical for preserving biodiversity, mitigating climate change, and maintaining ecosystem services in the coming century. To evaluate the relative roles of the abiotic environment and human disturbance on Central African tree community composition, we employ tree inventory data, remotely sensed climatic data, and soil nutrient data collected from 30 1‐ha plots distributed across a large‐scale observational experiment in forests that had been differently impacted by logging and hunting in northern Republic of Congo. We show that the composition of Afrotropical plant communities at this scale responds to human disturbance more than to climate, with particular sensitivities to hunting and distance to the nearest village (a proxy for other human activities, including tree‐cutting and gathering). These findings contrast neotropical predictions, highlighting the unique ecological, evolutionary, and anthropogenic history of Afrotropical forests. [ABSTRACT FROM AUTHOR]

Urbanization frequently alters the biotic and abiotic environmental context. Variation in both the biotic and abiotic environment can result in selection mosaics that lead to locally adapted phenotypes. Ecological changes to urban environments can result in evolutionary responses across a diverse array of plants and animals, but the effects of urbanization on local adaptation and coevolution between species remain largely unstudied.Using a common garden experiment of 30 populations and 1080 plants, we tested for local adaptation in the mutualism between white clover (Trifolium repens) and rhizobia (Rhizobium leguminosarum symbiovar trifolii) along an urbanization gradient. We asked: (Q1) are white clover and rhizobia locally adapted? (Q2) Does nitrogen (N) addition mediate the strength of local adaptation? (Q3) Is the strength of local adaptation in host plants related to the strength of local adaptation in rhizobia, as expected if white clover and rhizobia are coadapting? And (Q4) how does the degree of local adaptation vary with urbanization?We found evidence for local adaptation for both white clover and rhizobia, with stronger signatures of local adaptation for rhizobia than white clover (Q1). While N addition positively affected plant biomass and negatively affected nodule density, N addition did not consistently mediate patterns of local adaptation (Q2). The strength of local adaptation was positively related between white clover and rhizobia under N addition, suggesting that soil N mediates coadaptation between white clover and rhizobia (Q3). We did not find a consistent relationship between measures of urbanization and local adaptation (Q4). Additionally, fitness responses for white clover and rhizobia were unrelated to Rhizobium abundance and local adaptation was unrelated to the broader bacterial microbiome in the soil inoculants or root endosphere.Synthesis. Our results show a spatial mosaic in local adaptation, with stronger local adaptation for rhizobia than white clover. While urbanization does influence the ecology of plant–microbe interactions, our study suggests urbanization does not disrupt local adaptation and coevolution among mutualists. [ABSTRACT FROM AUTHOR]

This article discusses the important role that microbes play in plant ecology and evolution. Microbes, which include diverse soil and foliar microbial communities, have a significant impact on various aspects of plant biology. They can influence maternal effects, phenotypic plasticity, and natural selection in plants. Ignoring the presence and effects of microbes can lead to a misunderstanding of plant processes and outcomes. Therefore, it is crucial for plant ecologists and evolutionary biologists to consider the influence of microbial communities in their research to gain a more accurate understanding of plant biology in the natural world. [Extracted from the article]

In this paper, we redefine the target of evolutionary explanations by proposing the "evosystem" as an alternative to populations, lineages and species. Evosystems account for changes in the distribution of heritable variation within individual Darwinian populations (evolution by natural selection, drift, or constructive neutral evolution), but also for changes in the networks of interactions within or between Darwinian populations and changes in the abiotic environment (whether these changes are caused by the organic entities or not). The evosystem can thereby become a centerpiece for a redefined evolutionary science, that is, evolutionary studies, that apprehends through a single framework the variety of evolutionary processes that lie at various scales. To illustrate the importance of this broadened perspective on evolution, we use a case of antimicrobial resistance evolution: the spread of the blaNDM gene family and the related resistance to carbapenem antibiotics observed globally, and show how evolutionary studies can contribute to answering contemporary socially relevant challenges. [ABSTRACT FROM AUTHOR]

Our understanding of plant functional trait variation among populations and how this relates to local adaptation to environmental conditions is largely shaped by above‐ground traits. However, we might expect below‐ground traits linked to resource acquisition and conservation to vary among populations that experience different environmental conditions. Alternatively, below‐ground traits might be highly plastic in response to growing conditions, such as availability of soil resources and association with symbiont arbuscular mycorrhizal fungi (AMF).We assessed (i) the strength of among‐population variation in above‐ and below‐ground traits, (ii) the effects of growing conditions on among‐population variation and (iii) whether variation among populations is linked to source environment conditions, in a globally distributed perennial Plantago lanceolata. Using seeds from 14 populations across three continents, we grew plants in a common garden experiment and measured leaf and root traits linked to resource acquisition and water conservation. We included two sets of experimental treatments (high or low water availability; with and without AMF inoculation), which enabled us to assess trait responses to growing conditions.Across treatments, the percentage of root trait variation explained by populations and continents was 9%–26%, compared to 7%–20% for leaf trait variation. From principal component analysis (PCA), the first PC axis for both root and leaf traits largely reflected plant size, while the second PC broadly captured mass allocation. Root mass allocation (PC 2) was related to mean annual temperature and mean moisture index, indicating that populations from cooler, wetter environments had longer, thinner roots. However, we found little support for a relationship between source environment and leaf trait PCs, root system size (PC1) or individual traits. Water availability and AMF inoculation effects on size were consistent among populations, with larger plants under AMF inoculation, and less mass allocation to leaves under lower water availability.Plantago lanceolata shows substantial population‐level variation in a suite of root traits, but that variation is only partially linked to the source environmental variables studied. Despite considerable differences in source abiotic environments, geographically separated populations have retained a strong and similar capacity for phenotypic plasticity both above and below‐ground. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Many plant species can exhibit remarkable variation in leaf characteristics, depending on their abiotic and biotic environment. Environmental changes therefore have the potential to alter leaf traits, which in turn scale up to influence ecosystem processes including net primary productivity, susceptibility to fire, and palatability to herbivores. It is not well understood how consistent trait–environment relationships are among species, across sites and over time. This presents a fundamental challenge for functional ecology, because no study can measure all relevant species in all places at all times. Thus, understanding the limits of transferability is critical. We collected leaf trait measurements on 13 species of grass (family: Poaceae) across 11 sites and five years (n = 3091 individuals). Sites were arrayed along a spatial precipitation gradient in coastal northern California (annual precipitation of 590–1350 mm) with substantial interannual precipitation variability (from 60% below the 30‐year average to 100% above average). Temporal and spatial linear relationships between precipitation and specific leaf area (SLA) appear at first idiosyncratic, with each species sometimes displaying positive and sometimes negative responses. However, this variation arises from sampling different portions of an underlying hump‐shaped relationship, which was shared across most species. This hump‐shaped relationship was driven primarily by changes in leaf tissue density. These results suggest the potential for transferability among species, as well as between space and time, as long as the gradients are sufficiently long to capture the nonlinear response. Future work could explore the physiological basis of the nonlinear SLA response, including the possibility that distinct physiological mechanisms are operating at the two extremes of the gradient. [ABSTRACT FROM AUTHOR]

Sediment bypassing connects the upstream and downstream regions of dam impoundments through tunnels and is expected to partly restore natural processes (flood pulse and sediment regime) in dam‐altered river ecosystems. However, few reports examined the effects of restoration on stream biota. We examined the effectiveness of repeated sediment bypassing (12 times) over a period of 5 years in a Japanese dammed river using a before‐after‐reference‐impact design. We compared the abiotic parameters (water quality and substrate environment), biotic assemblages (algae, macroinvertebrates, and fish), and similarities between the dam downstream and undammed reference reaches. The reference sites exhibited high temporal variability in abiotic environments and species composition over the 5‐year period. Most abiotic and biotic parameters downstream of the dam improved and approached those of the changing reference states. However, these indices returned to pretrial conditions after the last trial. Biotic similarities between the downstream and reference reaches gradually increased throughout successive sediment‐bypassing trials for macroinvertebrates and algae; however, these similarities diminished after the last trial. Conversely, the abundance‐based composition of fish assemblages in the restored reach consistently diverged from that of the reference conditions throughout the study period. Our results show that the success and failure of restoration by sediment bypassing may be affected by the amount of bedload in the flushing flows and other regional processes such as migratory connectivity. Sediment bypassing can partially re‐establish natural processes and is a useful tool for improving sediment‐associated environments and biota. [ABSTRACT FROM AUTHOR]

Premise: The soil microbiome plays a role in plant trait expression and fitness, and plants may be locally adapted or maladapted to their soil microbiota. However, few studies of local adaptation in plants have incorporated a microbial treatment separate from manipulations of the abiotic environment, so our understanding of microbes in plant adaptation is limited. Methods: Here we tested microbial effects on local adaptation in four paired populations of an abundant alpine plant from two community types, dry and moist meadow. In a 5‐month greenhouse experiment, we manipulated source population, soil moisture, and soil microbiome and measured plant survival and biomass to assess treatment effects. Results: Dry meadow populations had higher biomass than moist meadow populations at low moisture, demonstrating evidence of local adaptation to soil moisture in the absence of microbes. In the presence of microbes, dry meadow populations had greater survival than moist meadow populations when grown with dry meadow microbes regardless of moisture. Moist meadow populations showed no signs of adaptation or maladaptation. Conclusions: Our research highlights the importance of microbial mutualists in local adaptation, particularly in dry environments with higher abiotic stress. Plant populations from environments with greater abiotic stress exhibit different patterns of adaptation when grown with soil microbes versus without, while plant populations from less abiotically stressful environments do not. Improving our understanding of the role microbes play in plant adaptation will require further studies incorporating microbial manipulations. [ABSTRACT FROM AUTHOR]

Premise: Astragalus (Fabaceae), with more than 3000 species, represents a globally successful radiation of morphologically highly similar species predominant across the northern hemisphere. It has attracted attention from systematists and biogeographers, who have asked what factors might be behind the extraordinary diversity of this important arid‐adapted clade and what sets it apart from close relatives with far less species richness. Methods: Here, for the first time using extensive phylogenetic sampling, we asked whether (1) Astragalus is uniquely characterized by bursts of radiation or whether diversification instead is uniform and no different from closely related taxa. Then we tested whether the species diversity of Astragalus is attributable specifically to its predilection for (2) cold and arid habitats, (3) particular soils, or to (4) chromosome evolution. Finally, we tested (5) whether Astragalus originated in central Asia as proposed and (6) whether niche evolutionary shifts were subsequently associated with the colonization of other continents. Results: Our results point to the importance of heterogeneity in the diversification of Astragalus, with upshifts associated with the earliest divergences but not strongly tied to any abiotic factor or biogeographic regionalization tested here. The only potential correlate with diversification we identified was chromosome number. Biogeographic shifts have a strong association with the abiotic environment and highlight the importance of central Asia as a biogeographic gateway. Conclusions: Our investigation shows the importance of phylogenetic and evolutionary studies of logistically challenging "mega‐radiations." Our findings reject any simple key innovation behind high diversity and underline the often nuanced, multifactorial processes leading to species‐rich clades. [ABSTRACT FROM AUTHOR]

Changes in telomere length are increasingly used to indicate species' response to environmental stress across diverse taxa. Despite this broad use, few studies have explored telomere length in plants. Thus, evaluation of new approaches for measuring telomeres in plants is needed. Rapid advances in sequencing approaches and bioinformatic tools now allow estimation of telomere content from whole‐genome sequencing (WGS) data, a proxy for telomere length. While telomere content has been quantified extensively using quantitative polymerase chain reaction (qPCR) and WGS in humans, no study to date has compared the effectiveness of WGS in estimating telomere length in plants relative to qPCR approaches. In this study, we use 100 Populus clones re‐sequenced using short‐read Illumina sequencing to quantify telomere length comparing three different bioinformatic approaches (Computel, K‐seek and TRIP) in addition to qPCR. Overall, telomere length estimates varied across different bioinformatic approaches, but were highly correlated across methods for individual genotypes. A positive correlation was observed between WGS estimates and qPCR, however, Computel estimates exhibited the greatest correlation. Computel incorporates genome coverage into telomere length calculations, suggesting that genome coverage is likely important to telomere length quantification when using WGS data. Overall, telomere estimates from WGS provided greater precision and accuracy of telomere length estimates relative to qPCR. The findings suggest WGS is a promising approach for assessing telomere length and, as the field of telomere ecology evolves, may provide added value to assaying response to biotic and abiotic environments for plants needed to accelerate plant breeding and conservation management. [ABSTRACT FROM AUTHOR]

Urbanization is changing the conditions in which many species live, forcing them to adjust to these novel environments. Floral size and shape are critical traits for the reproduction of plants pollinated by animals as they are involved in the attraction of pollinators and in efficient pollination. Variation in size and shape could be affected by urbanization via its modification of the abiotic environment (habitat fragmentation, water availability, temperature, soil properties), or via its impact on the biotic environment of plants (pollination, herbivory). Although numerous studies have assessed the impact of urbanization on pollinator communities and many plant traits, few have investigated its impact on floral size and shape while quantifying the proportion of the total urbanization effect that is due to biotic interactions. In this study, we tested if urbanization and pollinator visitation rates affect the flower shape of the spotted jewelweed, Impatiens capensis. We quantified the size and shape of flowers in frontal and profile views using geometric morphometrics for 228 individuals from six populations from the region of Montreal, Canada. Pollinator visitation rates were estimated at each site and the main pollinators were found to be bumblebees, honeybees and hummingbirds. We found that floral size and shape are significantly correlated with urbanization as measured by the amount of vegetation in the surrounding environment of the plants (mean normalized vegetation index, NDVI) and by the visitation rates of bumblebees and honey bees. Partitioning of the total flower shape variation suggests that urbanization affects flower shape through abiotic factors and via its impact on pollinator visitation rates. While further studies from other cities are necessary to confirm the role of urbanization in shaping the floral shape of I. capensis, these results support the idea that urbanization could affect flower shapes. [ABSTRACT FROM AUTHOR]

The expansion of woody species from their historical ranges into grasslands is a global problem. Understanding the mechanisms that enable species to successfully establish and then re‐encroach following their removal is critical to effectively managing problem species. Legacy effects are a mechanism that could be critical to the reestablishment of woody encroachers following their removal. Legacy effects occur when a species alters the biotic and abiotic environment in a way that affects communities that establish subsequently. In this study, we assess whether the eastern redcedar (Juniperus virginiana), a North American woody encroacher, generates legacy effects that affect communities that establish following removal of this species from an experimental grass community. We conducted a series of experiments to evaluate the effects of J. virginiana, roots on the germination and growth of grasses and to determine if the effects of root‐addition treatments were derived from a microbial or allelopathic origin. Aqueous extracts of J. virginiana roots were found to inhibit the germination of grasses. We found escalating suppression of overall community biomass and the biomass of each individual species with increasing root treatments. Finally, we determined the origin of the observed suppressive effect is unlikely to be of microbial origin. Synthesis: Our results suggest that J. virginiana exudes an allelochemical into soils that inhibits the growth of certain grasses and thus has the potential to have legacy effects on future occupants. We suggest that the inhibition of the development of grasses in areas where J. virginiana has been removed is a mechanism that may favor the reestablishment of J. virginiana. Our results indicate the legacy effects of J. virginiana must be considered when conducting removal and restoration of J. virginiana infested lands. [ABSTRACT FROM AUTHOR]

Summary: Predicting and managing the structure and function of plant microbiomes requires quantitative understanding of community assembly and predictive models of spatial distributions at broad geographic scales.Here, we quantified the relative contribution of abiotic and biotic factors to the assembly of phyllosphere bacterial communities, and developed spatial distribution models for keystone bacterial taxa along a latitudinal gradient, by analyzing 16S rRNA gene sequences from 1453 leaf samples taken from 329 plant species in China.We demonstrated a latitudinal gradient in phyllosphere bacterial diversity and community composition, which was mostly explained by climate and host plant factors. We found that host‐related factors were increasingly important in explaining bacterial assembly at higher latitudes while nonhost factors including abiotic environments, spatial proximity and plant neighbors were more important at lower latitudes. We further showed that local plant–bacteria associations were interconnected by hub bacteria taxa to form metacommunity‐level networks, and the spatial distribution of these hub taxa was controlled by hosts and spatial factors with varying importance across latitudes.For the first time, we documented a latitude‐dependent importance in the driving factors of phyllosphere bacteria assembly and distribution, serving as a baseline for predicting future changes in plant phyllosphere microbiomes under global change and human activities. [ABSTRACT FROM AUTHOR]

Many organisms actively manipulate the environment in ways that feed back on their own development, a process referred to as developmental niche construction. Yet, the role that constructed biotic and abiotic environments play in shaping phenotypic variation and its evolution is insufficiently understood. Here, we assess whether environmental modifications made by developing dung beetles impact the environment‐sensitive expression of secondary sexual traits. Gazelle dung beetles both physically modify their ontogenetic environment and structure their biotic interactions through the vertical inheritance of microbial symbionts. By experimentally eliminating (i) physical environmental modifications and (ii) the vertical inheritance of microbes, we assess the degree to which (sym)biotic and physical environmental modifications shape the exaggeration of several traits varying in their degree and direction of sexual dimorphism. We expected the experimental reduction of a larva's ability to shape its environment to affect trait size and scaling, especially for traits that are sexually dimorphic and environmentally plastic. We find that compromised developmental niche construction indeed shapes sexual dimorphism in overall body size and the absolute sizes of male‐limited exaggerated head horns, the strongly sexually dimorphic fore tibia length and width, as well as the weakly dimorphic elytron length and width. This suggests that environmental modifications affect sex‐specific phenotypic variation in functional traits. However, most of these effects can be attributed to nutrition‐dependent plasticity in size and non‐isometric trait scaling rather than body‐size‐independent effects on the developmental regulation of trait size. Our findings suggest that the reciprocal relationship between developing organisms, their symbionts, and their environment can have considerable impacts on sexual dimorphism and functional morphology. [ABSTRACT FROM AUTHOR]

Whole‐genome duplication has long been appreciated for its role in driving phenotypic novelty in plants, often altering the way organisms interface with the abiotic environment. Only recently, however, have we begun to investigate how polyploidy influences interactions of plants with other species, despite the biotic niche being predicted as one of the main determinants of polyploid establishment. Nevertheless, we lack information about how polyploidy affects the diversity and composition of the microbial taxa that colonize plants, and whether this is genotype‐dependent and repeatable across natural environments. This information is a first step towards understanding whether the microbiome contributes to polyploid establishment. We, thus, tested the immediate effect of polyploidy on the diversity and composition of the bacterial microbiome of the aquatic plant Spirodela polyrhiza using four pairs of diploids and synthetic autotetraploids. Under controlled conditions, axenic plants were inoculated with pond waters collected from 10 field sites across a broad environmental gradient. Autotetraploids hosted 4%–11% greater bacterial taxonomic and phylogenetic diversity than their diploid progenitors. Polyploidy, along with its interactions with the inoculum source and genetic lineage, collectively explained 7% of the total variation in microbiome composition. Furthermore, polyploidy broadened the core microbiome, with autotetraploids having 15 unique bacterial taxa in addition to the 55 they shared with diploids. Our results show that whole‐genome duplication directly leads to novelty in the plant microbiome and importantly that the effect is dependent on the genetic ancestry of the polyploid and generalizable over many environmental contexts. [ABSTRACT FROM AUTHOR]

The realised ecological niches of species may change in response to dynamic abiotic and biotic environments, particularly under fast global change. To fully understand the dynamics of niche features and their drivers, it is essential to have a long‐term view of species distributions and the factors that may have influenced them.Here, we analysed the distribution and niche dynamics of the Italian crayfish (Austropotamobius fulcisianus) in the Iberian Peninsula over the past 200 years. The Italian crayfish was introduced to Spain in the 16th century, and spread due to multiple stocking events until the 1970s, when two North American crayfish (red swamp crayfish Procambarus clarkii, and signal crayfish Pacifastacus leniusculus) were introduced. Both North American species are carriers of a pathogen (Aphanomyces astaci, the causal agent of crayfish plague) lethal to the Italian crayfish. We hypothesised that the realised niche of the Italian crayfish, both in breadth and in position, has changed over time following changes in its range.The distribution of the Italian crayfish expanded from the mid‐19th century until the mid‐20th century, in association with an enlargement of its realised niched, mostly towards less abrupt and more coastal‐influenced areas. After the introduction of the North American crayfishes, the collapse of the Italian crayfish involved a niche shift towards rough terrains in mountain areas. North American crayfish have eventually occupied most of the Italian crayfish's niche space, with the few no‐coexistence areas being relegated to the most abrupt and high‐elevation territories.Our historical approach allowed us to document and understand the highly dynamic distribution and niche of the Italian crayfish in the presence of invader counterparts, and to explore the environmental conditions under which their coexistence is minimised. [ABSTRACT FROM AUTHOR]

Freshwater mussels (Bivalvia: Unionidae) are often described as ecosystem engineers, with the capacity to alter abiotic habitats; this can facilitate certain macroinvertebrate taxa, increasing biodiversity and potentially altering community composition. Mussel species are often implicitly considered to be broad ecological equivalents, with similar impacts on abiotic environments and benthic communities. This assumption of redundancy is important in conservation approaches that aim to preserve ecosystem functioning, rather than species identity. We tested this assumption of equivalence in two species of subtropical freshwater mussels, Lamellidens marginalis and Parreysia caerulea, studying the associations between these mussel species and macroinvertebrate communities.We measured mussel density and abundance of macroinvertebrates, identified to family level, at 50 sites within Dhanmondi Lake, a heavily polluted sub‐tropical urban lake in Dhaka, Bangladesh. We investigated the associations of mussel density on different macroinvertebrate families, which we further classified into functional feeding groups (predators, scrapers, collectors and shredders).We found that densities of the two mussel species were negatively correlated in the 1–3‐m nearshore zone; average density of Lamellidens was 46.4 ± SE 3.6 individuals/0.25 m2, and average density of Parreysia was 6.4 ± SE 1.4 individuals/0.25 m2. In total, 2319 Lamellidens and 320 Parreysia specimens were recorded. Sites containing higher densities of Lamellidens had greater similarity in macroinvertebrate community composition, while there was no effect for Parreysia. Particular macroinvertebrate families and functional feeding groups were also associated with mussels; the majority of significant associations were with Lamellidens but not Parreysia. The clearest associations were with predators and scrapers, which increased in abundance with Lamellidens density.This provides support for a possible role for mussels in structuring freshwater invertebrate communities and emphasises the importance of species identity in these effects, with one possible keystone species (Lamellidens) largely accounting for mussel–invertebrate associations. While microhabitat variables (shading and sediment type) were poor predictors of abundance in any invertebrate taxa (including mussels), manipulative studies are needed to disentangle the direct effects of mussels from the role of overlapping habitat preference between mussels and other invertebrates.Our results highlight the importance of species identity in patterns of community composition, particularly for ecosystem engineer species. We also reinforce the need to test the assumption of ecological redundancy within communities. [ABSTRACT FROM AUTHOR]

Invasive plant transformers substantially change the abiotic environment of invaded ecosystems and thus habitat suitability to resident species. Post‐invasion environmental alteration can also modify the selective pressure acting on native plants. Here, I explored whether the decrease in light availability due to an invasion of Heracleum mantegazzianum drives evolution of reproductive strategies of Veronica chamaedrys, a perennial plant combining sexual and clonal reproduction.Using a common garden experiment with plant material of V. chamaedrys from 23 sites with distinct invasion history and light conditions, I searched for changes in reproductive allocation. I also asked whether evolution of the two modes can be constrained by the genetic trade‐off between them. Furthermore, the phenotypic trade‐off between the two modes was explored in a field experiment.I found that invaded populations increased investments in clonal reproduction, a shift that was driven by decreased light availability, particularly in the early invasion phases. However, as light availability rebounded in the more advanced phases of invasion, so decreased allocation to clonal structures. In terms of relative allocation, increased investment in ramets was paralleled by reduced seed production, and the changes were underpinned by genetic trade‐off. Finally, the phenotypic trade‐off was demonstrated in the field experiment by showing that plants producing more ramets were also less likely to flower.These results suggest that an exotic plant invasion can drive evolution of reproductive allocation, here observed on a timescale of tens of years. This knowledge is important not only for the prediction of long‐term invasion impacts, but also, more generally, for the provision of novel insights into the process of adaptation of plants to changing abiotic conditions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The coral skeleton harbours a diverse community of bacteria and microeukaryotes exposed to light, O2 and pH gradients, but how such physicochemical gradients affect the coral skeleton microbiome remains unclear. In this study, we employed chemical imaging of O2 and pH, hyperspectral reflectance imaging and spatially resolved taxonomic and inferred functional microbiome characterization to explore links between the skeleton microenvironment and microbiome in the reef‐building corals Porites lutea and Paragoniastrea benhami. The physicochemical environment was more stable in the deep skeleton, and the diversity and evenness of the bacterial community increased with skeletal depth, suggesting that the microbiome was stratified along the physicochemical gradients. The bulk of the coral skeleton was in a low O2 habitat, whereas pH varied from pH 6–9 with depth. Physicochemical gradients of O2 and pH of the coral skeleton explained the β‐diversity of the bacterial communities, and skeletal layers that showed O2 peaks had a higher relative abundance of endolithic algae, reflecting a link between the abiotic environment and the microbiome composition. Our study links the physicochemical, microbial and functional landscapes of the coral skeleton and provides new insights into the involvement of skeletal microbes in the coral holobiont metabolism. [ABSTRACT FROM AUTHOR]

As the global climate crisis continues, predictions concerning how wild populations will respond to changing climate conditions are informed by an understanding of how populations have responded and/or adapted to climate variables in the past. Changes in the local biotic and abiotic environment can drive differences in phenology, physiology, morphology and demography between populations leading to local adaptation, yet the molecular basis of adaptive evolution in wild non‐model organisms is poorly understood. We leverage comparisons between two lineages of Calochortus venustus occurring along parallel transects that allow us to identify loci under selection and measure clinal variation in allele frequencies as evidence of population‐specific responses to selection along climatic gradients. We identify targets of selection by distinguishing loci that are outliers to population structure and by using genotype–environment associations across transects to detect loci under selection from each of nine climatic variables. Despite gene flow between individuals of different floral phenotypes and between populations, we find evidence of ecological specialization at the molecular level, including genes associated with key plant functions linked to plant adaptation to California's Mediterranean climate. Single‐nucleotide polymorphisms (SNPs) present in both transects show similar trends in allelic similarity across latitudes indicating parallel adaptation to northern climates. Comparisons between eastern and western populations across latitudes indicate divergent genetic evolution between transects, suggesting local adaptation to either coastal or inland habitats. Our study is among the first to show repeated allelic variation across climatic clines in a non‐model organism. [ABSTRACT FROM AUTHOR]

Microhabitat differentiation of species communities such as vertical stratification in tropical forests contributes to species coexistence and thus biodiversity. However, little is known about how the extent of stratification changes during forest recovery and influences community reassembly. Environmental filtering determines community reassembly in time (succession) and in space (stratification), hence functional and phylogenetic composition of species communities are highly dynamic. It is poorly understood if and how these two concurrent filters—forest recovery and stratification—interact.In a tropical forest chronosequence in Ecuador spanning 34 years of natural recovery, we investigated the recovery trajectory of ant communities in three overlapping strata (ground, leaf litter, lower tree trunk) by quantifying 13 traits, as well as the functional and phylogenetic diversity of the ants. We expected that functional and phylogenetic diversity would increase with recovery time and that each ant community within each stratum would show a distinct functional reassembly. We predicted that traits related to ant diet would show divergent trajectories reflecting an increase in niche differentiation with recovery time. On the other hand, traits related to the abiotic environment were predicted to show convergent trajectories due to a more similar microclimate across strata with increasing recovery age.Most of the functional traits and the phylogenetic diversity of the ants were clearly stratified, confirming previous findings. However, neither functional nor phylogenetic diversity increased with recovery time. Community‐weighted trait means had complex relationships to recovery time and the majority were shaped by a statistical interaction between recovery time and stratum, confirming our expectations. However, most trait trajectories converged among strata with increasing recovery time regardless of whether they were related to ant diet or environmental conditions.We confirm the hypothesized interaction among environmental filters during the functional reassembly in tropical forests. Communities in individual strata respond differently to recovery, and possible filter mechanisms likely arise from both abiotic (e.g. microclimate) and biotic (e.g. diet) conditions. Since vertical stratification is prevalent across animal and plant taxa, our results highlight the importance of stratum‐specific analysis in dynamic ecosystems and may generalize beyond ants. [ABSTRACT FROM AUTHOR]

Laboratory assays show that parasites often have lower heat tolerance than their hosts. But how physiological tolerances and behavioral responses of hosts and parasites combine to affect their ecological interactions in heterogeneous field environments is largely unknown. We addressed this challenge using the model insect system of the braconid wasp parasitoid, Cotesia congregata, and its caterpillar host, Manduca sexta. We used experimental manipulations of microclimate in the field to determine how elevated daytime temperatures altered the behavior, performance, and survival of host and parasite. Our experimental manipulation increased daily maximum temperatures on host plants, but had negligible effects on overall mean temperature. These increased maximum temperatures resulted in subtle, biologically relevant, changes in physiology and behavior of the host and parasitoid. We found that parasitism by the wasp did not significantly alter caterpillar thermoregulatory behavior, while experimentally increased daily maximum temperatures resulted in both parasitized and unparasitized caterpillars to be found more frequently in cooler microhabitats. Overall, we did not observe the complete parasitoid mortality seen at extreme temperatures in laboratory studies, but gained insight into the sublethal effects of increased daily maximum temperatures on host and parasitoid behavior and physiology. Climate change will alter both the biotic and abiotic environments that organisms face, and we show here that empirical experiments in the field are important for understanding organismal response to these new environments. [ABSTRACT FROM AUTHOR]

Observed biodiversity–ecosystem function (BEF) relationships are highly variable, particularly in natural forests. However, our understanding of the factors that generate these often contradictory patterns, especially the role of different mycorrhizal associations, is still limited.By relating tree species richness and above‐ground biomass (AGB) in a fully mapped 24‐ha subtropical forest dynamics plot, we evaluated the impacts of soil fertility and tree mycorrhizal type in mediating BEF relationships at multiple spatial scales.Our results demonstrate a highly positive total richness effect on AGB for arbuscular mycorrhizal (AM) trees but a negative effect on AGB for ectomycorrhizal (EcM) trees, and their relationships were highly spatial scale dependent. However, the observed BEF relationships turned into positive at small spatial scales (i.e. 10 and 20 m) after controlling for other confounding factors (i.e. topography, soil fertility and AM proportion). In addition, we found significant interactions between soil fertility and species richness on AGB. Specifically, the positive effect of total species richness on AGB for major mycorrhizal types gradually weakened with increasing soil fertility, while the positive effect of EcM species richness on AM AGB gradually enhanced at small spatial scales, suggesting the observed diversity effects can be largely attributed to resource niche complementarity and the role of EcM fungi.Synthesis. We conclude that the variable BEF relationships among forest communities could be explained by spatial variation in abiotic environments and community mycorrhizal composition because different types of symbionts perform different nutrient uptake strategies and ability in protection from antagonists. Our findings provide novel insights into the understanding of the variation in the shape of BEF relationships in natural forests, which is critical for forest management, conservation and restoration in a changing world. [ABSTRACT FROM AUTHOR]

Shifting focus from among to within species studies of intraspecific demographic variation and functional traits is needed because climate change effects on demography may vary among populations of the same species. However, species-level trait values are often applied to all individuals, regardless of their population or its abiotic and biotic environments, thus ignoring the range of trait variation within and among populations (Figure 1A). Keywords: demographic rates; environmental contexts; functional traits; interactive effects; intraspecific variation EN demographic rates environmental contexts functional traits interactive effects intraspecific variation 1 4 4 05/31/23 20230501 NES 230501 BACKGROUND Plant ecologists have long sought to quantify the drivers of variation in growth, survival, and reproductive output (Harper and White, [8]). Better integration of feedbacks between ecology and evolution will also lend insight into how traits, environment, and demography interact to drive population dynamics. [Extracted from the article]

Urbanization is associated with numerous changes to the biotic and abiotic environments, many of which lead to a loss of biodiversity. Some studies have documented increased herbivory rates in cities, which has been hypothesized to lead to the evolution of novel defence traits in plants. Yet evidence supporting this hypothesis is contradictory and entirely absent from South American cities. To address this research gap, we evaluated herbivory rates in the native urban wildflower, Turnera subulata (Turneraceae), along an urbanization gradient in Joao Pessoa, Brazil. We predicted that higher rates of herbivory in cities would lead to the expression of cyanogenesis, a chemical defence found in a closely related Turnera species. We estimated herbivory rates and screened for cyanogenesis in 32 populations along the urbanization gradient, quantified by the Human Footprint Index and the amount of impervious surface surrounding each site. We found herbivory rates increased in T. subulata populations with increasing urbanization, but we did not find evidence of cyanogenesis in any of the populations. Our results suggest that although herbivores respond positively to urbanization, the fitness effects of leaf herbivory may be insufficient to select for the evolution of cyanogenesis in some plants. Our results provide valuable insight into the effects of urbanization on plant‐herbivore interactions in the tropics. [ABSTRACT FROM AUTHOR]

Dr. Moe Abbas, an Assistant Professor at Utrecht University, shares his experiences in academia and his research interests in plant biology. His research focuses on understanding how plants sense and coordinate environmental signals, particularly in relation to altitude adaptation. Dr. Abbas emphasizes the importance of patience, looking at the big picture, and enjoying the process of being a scientist. He also compares himself to a bamboo plant, highlighting the ability to adapt and thrive in different environments. [Extracted from the article]

Summary: Plants produce large numbers of phytochemical compounds affecting plant physiology and interactions with their biotic and abiotic environment. Recently, chemodiversity has attracted considerable attention as an ecologically and evolutionary meaningful way to characterize the phenotype of a mixture of phytochemical compounds.Currently used measures of phytochemical diversity, and related measures of phytochemical dissimilarity, generally do not take structural or biosynthetic properties of compounds into account. Such properties can be indicative of the compounds' function and inform about their biosynthetic (in)dependence, and should therefore be included in calculations of these measures.We introduce the R package chemodiv, which retrieves biochemical and structural properties of compounds from databases and provides functions for calculating and visualizing chemical diversity and dissimilarity for phytochemicals and other types of compounds. Our package enables calculations of diversity that takes the richness, relative abundance and – most importantly – structural and/or biosynthetic dissimilarity of compounds into account. We illustrate the use of the package with examples on simulated and real datasets.By providing the R package chemodiv for quantifying multiple aspects of chemodiversity, we hope to facilitate investigations of how chemodiversity varies across levels of biological organization, and its importance for the ecology and evolution of plants and other organisms. [ABSTRACT FROM AUTHOR]

A core challenge in global change biology is to predict how species will respond to future environmental change and to manage these responses. To make such predictions and management actions robust to novel futures, we need to accurately characterize how organisms experience their environments and the biological mechanisms by which they respond. All organisms are thermodynamically connected to their environments through the exchange of heat and water at fine spatial and temporal scales and this exchange can be captured with biophysical models. Although mechanistic models based on biophysical ecology have a long history of development and application, their use in global change biology remains limited despite their enormous promise and increasingly accessible software. We contend that greater understanding and training in the theory and methods of biophysical ecology is vital to expand their application. Our review shows how biophysical models can be implemented to understand and predict climate change impacts on species' behavior, phenology, survival, distribution, and abundance. It also illustrates the types of outputs that can be generated, and the data inputs required for different implementations. Examples range from simple calculations of body temperature at a particular site and time, to more complex analyses of species' distribution limits based on projected energy and water balances, accounting for behavior and phenology. We outline challenges that currently limit the widespread application of biophysical models relating to data availability, training, and the lack of common software ecosystems. We also discuss progress and future developments that could allow these models to be applied to many species across large spatial extents and timeframes. Finally, we highlight how biophysical models are uniquely suited to solve global change biology problems that involve predicting and interpreting responses to environmental variability and extremes, multiple or shifting constraints, and novel abiotic or biotic environments. [ABSTRACT FROM AUTHOR]

Seasonal migrations are fascinating and ecologically important, but many migratory species are declining as climate change and land‐use change alter the habitats used by migrants across the annual cycle. While some migratory birds use a single wintering site, others undertake large‐scale post‐migratory movements during the nonbreeding season. Technological advances that enable tracking individual birds are uncovering more examples of post‐migratory nonbreeding movements. Documenting these movements is important for conservation, which requires understanding when and where migrants use habitats throughout their range. Here, we reviewed existing literature and collected information on the post‐migratory nonbreeding movements of 92 migratory bird species from 18 orders across six continents. Among these records, the most commonly reported drivers of movements were resource availability and climate. This strong dependence of post‐migratory nonbreeding movements on birds' abiotic and biotic environments suggests that environmental change will impact the patterns of these movements and potentially the fitness of species that undertake them. We also reviewed post‐migratory nonbreeding movements in North American‐breeding thrushes from the genus Catharus to examine the drivers of these movements in five closely related migratory species. We find that species that are less territorial are more likely to use multiple sites during the nonbreeding season; however, there is little evidence for dietary, evolutionary, or environmental differences between thrush species that move during winter and those that are stationary. While we believe our study represents the most comprehensive list of species exhibiting post‐migratory nonbreeding movements to date, biases in sampling, a lack of common terminology for these movements, and the still‐nascent availability of inexpensive, lightweight tracking devices mean that there are probably more populations that undertake such movements. Future research into the consequences of post‐migratory nonbreeding movements for individual fitness and ecosystem services would advance our understanding of their conservation importance and their evolution. [ABSTRACT FROM AUTHOR]

Questions: Plant traits can predict a species' relative abundance and its influence on ecosystem processes. However, trait expression and the relative abundance of a species are also influenced by its abiotic and biotic environment. Here, we ask whether the relationship between plant traits and relative abundance is modified by abiotic (e.g., climate and topography) and biotic factors (e.g., community taxonomic and functional diversity) across Californian grasslands. Location: San Francisco Bay Area. Methods: We measured specific leaf area (SLA; leaf area/dry mass) and plant height of 19 grass species (family: Poaceae) across 117 plots. We also quantified the relative abundance of each species as well as several biotic attributes of the neighboring grass community including total plant cover, species richness and evenness, community‐weighted mean (CWM) traits, and functional diversity. Using multiple linear regression, we assessed whether abundance could be predicted from traits and the interactions between traits and both biotic and abiotic factors. We fit similar models predicting traits from relative abundance. Results: Grass species had higher relative abundance in plots where they were taller and had higher SLA. They were also more abundant in communities with low functional richness (FRic) and high functional evenness (FEve), perhaps because of the low resource‐use efficiency of their neighbors and a lack of dominant grasses. Neither abundance nor plant height were associated with abiotic variables, although SLA responded predictably to precipitation according to a bell‐shaped curve. Grasses were taller where they were more abundant, but the impact of abundance on SLA depended on community FEve. Finally, we show strong evidence for community trait similarity, whereby an individual's trait expression was positively correlated with the traits of its grass neighbors. Conclusions: Taken together, these results imply that traits are predictive of abundance and vice versa, and these relationships depend on biotic interactions more than climate. [ABSTRACT FROM AUTHOR]

Uncovering drivers of community assembly is a key aspect of learning how biological communities function. Drivers of community similarity can be especially useful in this task as they affect assemblage‐level changes that lead to differences in species diversity between habitats. Concepts of β‐diversity originally developed for use in free‐living communities have been widely applied to parasite communities to gain insight into how infection risk changes with local conditions by comparing parasite communities across abiotic and biotic gradients.Factors shaping β‐diversity in communities of immature parasites, such as larvae, are largely unknown. This is a key knowledge gap as larvae are frequently the infective life‐stage and understanding variation in these larval communities is thus key for disease prevention. Our goal was to uncover links between β‐diversity of parasite communities at different life stages; therefore, we used gastrointestinal nematodes infecting African buffalo in Kruger National Park, South Africa, to investigate within‐host and extra‐host drivers of adult and larval parasite community similarity.We employed a cross‐sectional approach using PERMANOVA that examined each worm community at a single time point to assess independent drivers of β‐diversity in larvae and adults as well as a longitudinal approach with path analysis where adult and larval communities from the same host were compared to better link drivers of β‐diversity between these two life stages.Using the cross‐sectional approach, we generally found that intrinsic, within‐host traits had significant effects on β‐diversity of adult nematode communities, while extrinsic, extra‐host variables had significant effects on β‐diversity of larval nematode communities. However, the longitudinal approach provided evidence that intrinsic, within‐host factors affected the larval community indirectly via the adult community.Our results provide key data for the comparison of community‐level processes where adult and immature stages inhabit vastly different habitats (i.e. within‐host vs. abiotic environment). In the context of parasitism, this helps elucidate host infection risk via larval stages and the drivers that shape persistence of adult parasite assemblages, both of which are useful for predicting and preventing infectious disease. [ABSTRACT FROM AUTHOR]

Litters of leaves and roots of different qualities occur naturally above‐ and below‐ground, respectively, where they decompose in contrasting abiotic and biotic environments. Therefore, ecosystem carbon (C) and nitrogen (N) dynamics can be strongly affected by the combination of litter position and quality. However, it is poorly understood how C versus N turnover of litters depend on the interplay among plant functional type (PFT), organs, traits and litter position.In a semi‐arid inland dune, soil surface and buried leaf litters and buried fine roots of 25 species across three PFTs (herbs, legume shrubs and nonlegume shrubs) were incubated for 3, 6, 9, 12, 18 and 24 months to investigate litter decomposition and C and N dynamics. Morphological and chemical (nutrient and NMR carbon) traits of initial litters of leaves and fine roots were determined.The litter decomposition rates (k values) of surface leaves and buried fine roots did not differ, but buried fine roots and buried leaf litter decomposed faster than surface leaf litter. Ratios of k values of surface leaves to buried leaves decreased with leaf C:N ratio. Herbs and legume shrubs decomposed faster than nonlegume shrubs for buried fine roots, but not for leaves. At given C loss, buried fine roots had higher N loss than leaf litters; legume shrubs with relatively higher N or lower C:N ratio had higher N loss than nonlegume shrubs. Stronger positive relationships between C and N losses were shown in leaves and legume shrubs than in fine roots and nonlegume shrubs respectively.Synthesis. The generality of faster N release of legume litters at given C release highlights the importance of legumes in N cycling in semi‐arid ecosystems where N is the limiting factor. The dynamics and coordination of C versus N release as a function of litter quality are modulated by litter position and PFT. These findings have important implications for the development of process‐based models on C and N cycles in the context of on‐going global change potentially altering the functional composition of plant communities and the relative quantities and qualities of above‐ground versus below‐ground litter. [ABSTRACT FROM AUTHOR]

Aim: Due to the sessile nature of flowering plants, movements to new geographical areas occur mainly during seed dispersal. Frugivores tend to be efficient dispersers because animals move within the boundaries of their preferable niches, so seeds are more likely to be transported to environments that are similar to where the parent plant occurs. However, this efficiency can result in less opportunity for niche shifts over macroevolutionary time, 'trapping' plant lineages in particular climatic conditions. Here we test this hypothesis by analysing the role that the interaction with frugivores play in changing dynamics of climatic niche evolution in five clades of flowering plants. Location: Global. Taxon: The flowering plant families Apocynaceae, Ericaceae, Melastomataceae, Rosaceae and Solanaceae. Methods: We model climatic niche evolution as a variable parameter Ornstein–Uhlenbeck process. However, rather than assuming regimes a priori, we use a hidden Markov model (HMM) to infer the complex evolutionary history associated with different modes of seed dispersal. In addition to allowing for a more accurate picture of the regimes, the use of HMMs allows partitioning the variance of climatic niche evolution to include dynamics independent of our focal character. Results: Lineages dispersed by frugivores tend to have warmer and wetter climatic optima and are generally associated with areas where potential for vegetation growth is higher. However, lineages distributed in more mesic habitats, such as rainforests, are generally associated with slower rates of climatic niche evolution regardless of their mode of seed dispersal. Main Conclusions: Characteristics of the abiotic environment may facilitate the evolution of some types of plant–animal interactions. Association with frugivores is an important modulator of how plants move in space, but its impact on their climatic niche evolution appears to be indirect. Seed dispersal by frugivores may facilitate the establishment of lineages in closed canopy biomes, but the general slower rates of climatic niche evolution in these habitats are possibly related to other general aspects of the 'mesic syndrome' rather than the behaviour of the animals that disperse their seeds. [ABSTRACT FROM AUTHOR]