Find research datasets worth reusing

Data from: Lineage-specific trait variations and plasticity of obligate parthenogenetic animals following the expansion of distribution range to a continental archipelago.

Two asexual lineages, JPN1 and JPN2, of panarctic Daphnia pulex expanded the distribution range to Japan from North America, independent of each other. According to the mutation rates within these lineages, JPN1 lineage colonized Japan earlier than JPN2 lineage. Moreover, the ratio of nonsynonymous to synonymous mutation rates (dN/dS) was lower in JPN1 than in JPN2 lineage. Accordingly, it is hypothesized that variations of phenotypic traits differ between these two lineages. In addition, since they are obligate parthenogenetic animals, the lineage occupying a larger distribution range should have a larger phenotypic plasticity. To test these hypotheses, we experimentally examined the phenotypic variations of fitness-related traits, including digestive, life history and morphological traits, among several genotypes of these lineages. We found that within-lineage variations of most traits were smaller in JPN1 than in JPN2. In addition, the overall phenotypic variations were also smaller within the JPN1 lineage than within the JPN2 lineage. These results support the idea that the JPN1 lineage has been more efficiently subjected to negative selection, as expected from the lower dN/dS ratio. However, the magnitude of the phenotypic plasticity to changing food levels was at the same level for both the JPN1 and JPN2 lineages, while variations found in the phenotypic plasticity were smaller in the JPN1 lineage. The difference in the variations of the phenotypic traits and plasticity between the two lineages suggests that these two lineages have evolved under somewhat different environmental conditions and that genotypes of the JPN2 lineage may have exploited niches that differed somewhat from that of the JPN1 genotypes.

Broad- and small-scale environmental gradients drive variation in chemical, but not morphological, leaf traits of vascular epiphytes

Variation in leaf functional traits along environmental gradients can reveal how vascular epiphytes respond to broad- and small-scale environmental gradients. Along elevational gradients, both temperature and precipitation likely play an important role as drivers of leaf trait variation, but these traits may also respond to small-scale changes in light, temperature, and humidity along the vertical environmental gradient within forest canopies. However, the relative importance of broad- and small-scale environmental gradients as drivers of variation in leaf functional traits of vascular epiphytes is poorly understood. Here, we examined variation in morphological and chemical leaf traits of 102 vascular epiphyte species spanning two environmental gradients along Cofre de Perote mountain in Mexico: i) a broad-scale environmental gradient approximated by elevation as well as by species' lower and upper elevational limits, and ii) small-scale environmental gradients using the relative height of attachment of an epiphyte on a host tree as a proxy for variation in environmental conditions within the forest canopy. We also assessed whether variation in morphological and chemical leaf traits along these gradients were consistent across photosynthetic pathways (CAM and C3). Broad- and small-scale environmental gradients explained more variation in chemical traits (marginal R2: 11-89%) than in morphological traits (marginal R2: 2-31%). For example, leaf carbon isotope signatures (δ13C), which reflects water-use efficiency, varied systematically across both environmental gradients, suggesting a decrease in water-use efficiency with increasing lower and upper elevational limits and an increase in water-use efficiency with relative height of attachment. The influence of lower and upper elevational limits on trait variation differed between photosynthetic pathways, except for leaf dry matter content and leaf nitrogen-to-phosphorus ratio. Contrary to our expectations, broad- and small-scale environmental gradients explained minimal variation in morphological leaf traits, suggesting that environmental conditions do not constrain morphological leaf trait values of vascular epiphytes. Our findings suggest that assessing multiple drivers of leaf trait variation among photosynthetic pathways is key for disentangling the mechanisms underlying responses of vascular epiphytes to environmental conditions.

Root penetration index 3, a major quantitative trait locus (QTL) associated with root system penetrability in Arabidopsis.

Soil mechanical impedance precludes root penetration, confining root system development to shallow soil horizons where mobile nutrients are scarce. Using a two-phase-agar system, we characterized Arabidopsis thaliana responses to low and high mechanical impedance at three root penetration stages. We found that seedlings whose roots fail to penetrate agar barriers show a significant reduction in leaf area, root length and elongation zone and an increment in root diameter, while those capable of penetrating show only minor morphological effects. Analyses using different auxin-responsive reporter lines, exogenous auxins and inhibitor treatments suggest that auxin responsiveness and PIN-mediated auxin distribution play an important role in regulating root responses to mechanical impedance. The assessment of 21 Arabidopsis accessions revealed that primary root penetrability (PRP) varies widely among accessions. To search for quantitative trait loci (QTLs) associated to root system penetrability, we evaluated a recombinant inbred population (RIL) derived from Landsberg erecta (Ler-0, with a high PRP) and Shahdara (Sha, with a low PRP) accessions. QTL analysis revealed a major-effect QTL localized in chromosome 3 (q-RPI3), which accounted for 29.98% (LOD = 8.82) of the total phenotypic variation. Employing an introgression line (IL-321), with a homozygous q-RPI3region from Sha in the Ler-0 genetic background, we demonstrated that q-RPI3 plays a crucial role in root penetrability. This multiscale study revels new insights into root plasticity during the penetration process in hard agar layers, natural variation and genetic architecture behind primary root penetrability in Arabidopsis.

opencc-by-4.0May 2022View details →

Characterizing Subjects Exposed to Humidifier Disinfectants Using Computed Tomography-based Latent Traits: A Deep Learning Approach

Around nine million people had been exposed to toxic humidifier disinfectants (HDs) in Korea. HD-exposure may lead to HD-associated lung injuries (HDLI). However, many people who claimed HD exposure were not diagnosed of HDLI but still felt discomfort possibly due to the unknown effects of HD. Therefore, this study examined HD-exposed subjects with normal appearing lungs as well as unexposed subjects in clusters (subgroups) with distinct characteristics classified by deep-learning-derived computed-tomography (CT)-based tissue-pattern latent traits. Among the major clusters, cluster 0 (C0) and cluster 5 (C5) were dominated by HD-exposed and unexposed subjects, respectively. C0 was characterized by features attributable to lung inflammation or fibrosis compared with C5. The computational fluid and particle dynamics (CFPD) analysis suggested that the smaller airway sizes observed in the C0 subjects led to greater airway resistance and particle deposition in the airways. Accordingly, women appeared more vulnerable to HD-associated lung abnormality than men.

Macroclimatic and maternal effects on the evolution of reproductive traits in lizards

Much of life-history theory rests on fundamental assumptions about constraints on the acquisition and allocation of energy to growth and reproduction. In general, the allocation of energy to reproduction depends on maternal size, which in turn depends on environmental factors experienced throughout the life of the mother. Here, we used phylogenetic path analyses to evaluate competing hypotheses about the environmental and maternal drivers of reproductive traits in lizards. In doing so, we discovered that precipitation, rather than temperature, has shaped the evolution of the life history. Specifically, environments with greater rainfall have enabled the evolution of larger maternal size. In turn, these larger mothers produce larger clutches of larger offspring. However, annual precipitation has a negative direct effect on offspring size, despite the positive indirect effect mediated by maternal size. Possibly, the evolution of offspring size was driven by the need to conserve water in dry environments, because small organisms are particularly sensitive to water loss. Since we found that body size variation among lizards is related to a combination of climatic factors, mainly precipitation and perhaps primary production, our study challenges previous generalizations (e.g., temperature-size rule and Bergmann's rule) and suggests alternative mechanisms underlying the evolution of body size.

opencc-zeroDec 2021View details →

Data from: A trait‒environment relationship approach to participatory plant breeding for organic agriculture

The extent of intraspecific variation in trait‒environment relationships is an open question with limited empirical support in crops. In organic agriculture, with high environmental heterogeneity, this knowledge could guide breeding programs to optimize crop attributes. We propose a three-dimensional framework involving crop performance, crop traits, and environmental axes to uncover the multidimensionality of trait‒environment relationships within a crop. We modeled instantaneous photosynthesis (Asat) and water-use efficiency (WUE) as functions of four phenotypic traits, three soil variables, five carrot (D. carota) varieties, and their interactions in a national participatory plant breeding program involving a suite of farms across Canada. We used these interactions to describe the resulting 12 trait‒environment relationships across varieties. We found one significant trait‒environment relationship for Asat (taproot tissue density‒soil phosphorus), which was consistent across varieties. For WUE, we found that three relationships (petiole diameter‒soil nitrogen, petiole diameter‒soil phosphorus, and leaf area‒soil phosphorus) varied significantly across varieties. As a result, WUE was maximized by different combinations of trait values and soil conditions depending on the variety. Our three-dimensional framework supports the identification of functional traits behind the differential responses of crop varieties to environmental variation and thus guides breeding programs to optimize crop attributes from an eco-evolutionary perspective.

Behavioural and morphological traits influence sex-specific floral resource use by hummingbirds

Research on resource partitioning in plant-pollinator mutualistic systems is mainly concentrated at the levels of species and communities, whereas differences between males and females are typically ignored. Nevertheless, pollinators often show large sexual differences in behaviour and morphology, which may lead to sex-specific patterns of resource use with the potential to differentially affect plant reproduction and diversification. We investigated variation in behavioural and morphological traits between sexes of hummingbird species as potential mechanisms underlying sex-specific flower resource use in ecological communities. To do so, we compiled a dataset of plant-hummingbird interactions based on pollen loads for 31 hummingbird species from 13 localities across the Americas, complemented by data on territorial behaviour (territorial or nonterritorial) and morphological traits (bill length, bill curvature, wing length and body mass). We assessed the extent of intersexual differences in niche breadth and niche overlap in floral resource use across hummingbird species. Then, we tested whether floral niche breadth and overlap between sexes are associated with sexual dimorphism in behavioural or morphological traits of hummingbird species, while accounting for evolutionary relatedness among the species. We found striking differences in patterns of floral resource use between sex. Females had a broader floral niche breadth and were more dissimilar in the plant species visited with respect to males of the same species, resulting in a high level of resource partitioning between sexes. We found that both territoriality and morphological traits were related to sex-specific resource use by hummingbird species. Notably, niche overlap between sexes was greater for territorial than nonterritorial species, and moreover, niche overlap was negatively associated with sexual dimorphism in bill curvature across hummingbird species. These results reveal the importance of behavioural and morphological traits of hummingbird species in sex-specific resource use and that resource partitioning by sex is likely to be an important mechanism to reduce intersexual competition in hummingbirds. These findings highlight the need for better understanding the putative role of intersexual variation in shaping patterns of interactions and plant reproduction in ecological communities.

Genomic evidence that a sexually selected trait captures genome-wide variation and facilitates the purging of genetic load

The evolution of costly traits like deer antlers and peacock trains, which drove the formation of Darwinian sexual selection theory, has been hypothesised to both reflect and affect patterns of genetic variance across the genome, but direct tests are missing. Here, we used an evolve and re-sequence approach to reveal patterns of genome-wide diversity associated with the expression of a sexually-selected weapon that is dimorphic among males of the bulb mite, Rhizoglyphus robini. Populations selected for the weapon showed reduced genome-wide diversity compared to populations selected against the weapon, particularly in terms of the number of segregating non-synonymous positions, indicating enhanced purifying selection. This increased purifying selection reduced inbreeding depression, but outbred female fitness did not improve, possibly because any benefits were offset by increased sexual antagonism. The majority of single nucleotide polymorphisms (SNPs) that consistently diverged in response to selection were initially rare and overrepresented in exons, and enriched in regions under balancing or relaxed selection, suggesting they are likely moderately deleterious variants. These diverged SNPs were scattered across the genome, further demonstrating that selection for or against the weapon and the associated changes to the mating system can both capture and influence genome-wide variation.

Variable relationships between trait diversity and avian ecological functions in agroecosystems

1) The diversity of traits within animal assemblages has been shown to affect the magnitude of animal-provided ecological functions. However, little is known about how consistent trait diversity effects are across ecological functions and ecosystems. More importantly, the importance of trait diversity in driving ecosystem functioning, relative to other components of biodiversity, has rarely been assessed. It also remains unclear how environmental gradients filter trait diversity and, ultimately, modulate ecological functions. 2) Here we test how different biodiversity components (i.e., trait diversity, phylogenetic diversity and abundance) affect the magnitude of avian seed dispersal and insect predation along large environmental gradients. We sampled frugivorous and insectivorous birds and their ecological functions across gradients of forest cover and fruit and insect abundances in woodland pastures and apple orchards in Northern Spain. We measured 6 morphological traits and compiled phylogenetic information on 43 bird species. We used Structural Equation Models to disentangle the effects of environmental gradients and biodiversity components on ecological functions. 3) We found that different avian functions in the same agroecosystem were controlled by different biodiversity components. While seed dispersal was positively driven by bird abundance in woodland pastures, insect predation responded positively to trait and phylogenetic diversity. The positive effects of trait diversity on insect predation were, on the other hand, consistent across woodland pastures and apple orchards. 4) Our results also pinpointed forest cover and resource availability as filters of the different components of avian diversity, suggesting that environmental gradients condition the effects of biodiversity on avian ecological functions. 5) Our findings reveal variable effects of trait diversity on two different avian ecological functions, but consistent effects on the same function across agroecosystems. Consolidating the generalities of trait diversity effects will require further multi-function studies, as well as a unifying framework for animal-driven functions that integrates the causal links between environmental gradients, the different biodiversity components, and ecological functions.

A high-throughput assay for quantifying phenotypic traits of microalgae

High-throughput methods for phenotyping microalgae are in demand across a variety of research and commercial purposes. Many microalgae can be readily cultivated in multi-well plates for experimental studies which can reduce overall costs, while measuring traits from low volume samples can reduce handling. Here we develop a high-throughput quantitative phenotypic assay (QPA) that can be used to phenotype microalgae grown in multi-well plates. The QPA integrates 10 low-volume, relatively high-throughput trait measurements (growth rate, cell size, granularity, chlorophyll a, neutral lipid content, silicification, reactive oxygen species accumulation, and photophysiology parameters: ETRmax, Ik, and alpha) into one workflow. We demonstrate the utility of the QPA on Thalassiosira spp., a cosmopolitan marine diatom, phenotyping six strains in a standard nutrient rich environment (f/2 media) using the full 10-trait assay. The multivariate phenotypes of strains can be simplified into two dimensions using principal component analysis, generating a trait-scape. We determine that traits show a consistent pattern when grown in small volume compared to more typical large volumes. The QPA can thus be used for quantifying traits across different growth environments without requiring exhaustive large-scale culturing experiments, which facilitates experiments on trait plasticity. We confirm that this assay can be used to phenotype newly isolated diatom strains within 4 weeks of isolation. The QPA described here is highly amenable to customisation for other traits or unicellular taxa and provides a framework for designing high-throughput experiments. This method will have applications in experimental evolution, modelling, and for commercial applications where screening of phytoplankton traits is of high importance.

Intraspecific trait changes in response to drought lead to trait convergence between- but not within species

Drought is expected to increase in future climate scenarios. Although responses to drought of individual functional traits are relatively well-known, simultaneous changes across multiple traits in response to water scarcity remain poorly understood despite its importance to understand alternative strategies to resist drought. We grew 52 herbaceous species in monocultures under drought and control treatments and characterized the functional space using seven measured above- and belowground traits: plant height, leaf area, specific leaf area, leaf dry matter content, specific root length, average root diameter, and root dry matter content. Then, we estimated how each species occupied this space and the amount of functional space occupied in both treatments using trait probability density functions. We also estimated intraspecific trait variability (ITV) for each species as the dissimilarity in trait values between the individuals of each treatment. We then mapped drought resistance and ITV in the functional space using generalized additive models. The response of species to drought strongly depended on their traits, with species that invested more in root tissues and conserved small size being both more resistant to drought and having higher ITV. We also observed a significant trend of trait displacement towards less conservative strategies. However, these changes depended strongly on the trait values of species in the control treatment, with species with different traits having opposing responses to drought. These contrasting responses resulted in lower trait variability in the species pool in drought compared to control conditions. Our results suggest strong trait filtering acting on conservative species as well as the existence of an optimal part in the functional space to which species converge under drought. Our results show that changes in species trait-space occupancy are key to understand plant strategies to withstand drought, highlighting the importance of individual variation in response to environmental changes, and suggest that community-wide functional diversity and biomass productivity could decrease in a drier future. Knowing these shifts will help to anticipate changes in ecosystem functioning facing climate change.

opencc-zeroDec 2021View details →

Growth resilience of conifer species decreases with early, long-lasting and intense droughts but cannot be explained by hydraulic traits

Drought events may reduce growth and survival of conifer trees. The effects of the intensity and timing of drought on the growth resilience, including growth reductions during drought and recovery of growth after drought, remains however highly uncertain. Growth resilience of 20 conifer species to 11 dry years was compared in a common garden experiment. We assessed 1) the relationships among growth resistance, recovery and resilience, 2) the impacts of different drought dimensions (intensity, onset and length) on resistance, and 3) the underlying mechanisms in terms of growth potential and hydraulic traits. Droughts led to 22% reduction in stem growth for 85% of species, but most species (85%) were resilient due to high recovery. Growth resistance decreased with an early onset of drought (significant for 55% of species), and longer lasting (35%) and intense droughts (60%). While fast-growing species and slow-growing species were similar in resistance and recovery, fast-growing species were more resilient. Unexpectedly, resilience could not be explained by hydraulic traits, possibly because the species grew on poor sandy soils and were acclimated to drought with large hydraulic safety margins. Synthesis Our study shows that in a mild maritime climate almost all conifer species are resilient to drought, and that putative hydraulic traits may be less important here for growth resilience. It also highlights the importance of addressing multiple dimensions of drought, i.e., timing, duration and severity, to predict species responses to climate change.

Data for: Substantial intraspecific trait variation across a hydrological gradient in northern Australian fishes

Trait-based models of ecological communities and ecosystem functioning often fail to account for intraspecific variation in functional traits, assuming that intraspecific variability is negligible compared to interspecific variability. However, this assumption remains poorly tested across vertebrate animals where past studies routinely describe species according to mean trait values without explicit consideration of individual trait variability. We assessed nine functional traits for 4,254 individuals belonging to 15 freshwater fish species from 11 families in Northern Australia, including: body elongation, body shape, caudal peduncle throttle, eye size, eye position, gape shape, gape size, mouth position and pectoral fin length. We quantified the extent and geography of intraspecific trait variability and its relationship with riverine hydrologic regimes using a structured sampling design. Using a combination of single- and multi-trait analyses, we demonstrate that intraspecific trait variability can contribute up to 70% of the total trait variability depending on the attribute considered and averaged 31% across all traits. The magnitude of intraspecific trait variability also varied across the hydrological permanency gradient. Fish assemblages in intermittent streams subjected to frequent environmental disturbance had high intraspecific trait variability, most likely due to strong abiotic filters limiting interspecific divergence. Conversely, assemblages in perennial rivers with less harsh environmental filters but with a larger pool of species expressed lower intraspecific trait variability: this is most likely due to stronger resource competition (biotic filter), which promotes specialization of resource use and, consequently, interspecific divergence. Our study provides the first evidence of intraspecific trait variability driven by a disturbance gradient for an animal group and points to the need for additional research into the functional importance of intraspecific variability in animal ecology. A better understanding of the patterns, drivers, and implications of intraspecific trait variability will help guide mechanistic-based predictions of the effects of environmental changes on community assemblage and ecosystem processes.

Overyielding is accounted for partly by plasticity and dissimilarity of crop root traits in maize/legume intercropping systems

Positive biodiversity-productivity relationships have been found in biodiversity field experiments of grassland, forestry, and other natural terrestrial ecosystems, where diversity effects were separated by complementarity (CE) and selection effects (SE). However, we know little about how CE and SE are related to root traits and root dissimilarity. A four-year field experiment was carried out with a split-plot design, where main plot was four nitrogen (N) applications (N0, N1, N2, N3) and five cropping systems (maize (Zea mays L.)/soybean (Glycine max L. Merrill.), maize/peanut (Arachis hypogaea L.) intercropped and the corresponding monocultures) with three replicates. Roots were sampled in the N0 and N2 treatments in two years. Intercropping effects were analyzed based on grain yield for four years and roots were sampled down to 60 cm depth, and analyzed with morphological parameters at different crop growth stages in two years. Intercropping significantly increased grain yield and aboveground biomass in both intercropping systems under all N treatments. The partitioning of the net intercropping effects showed that yield advantage in intercropping was due to a positive CE under the N0 treatment, and to a positive SE with N application. Maize showed greater root morphological plasticity than the legumes did, with greater changes in root length density (RLD), root weight density (RWD) and total root surface (TS) in intercropping than in monoculture. Intercropped maize occupied a larger soil space, while lateral RLD distribution of legumes was decreased by maize. The RLD, RWD, and TS of intercropped maize were constant or increased in later growth stages. SE showed a significantly positive relationship with root dissimilarity. Principal component analysis showed mean root depth and specific root length of legumes drove the positive CE in the absence of N fertilization. Root dissimilarity determined by maize explained the selection effects in overyielding. Complementarity effects under N0 were closely associated with specific root traits such as mean root depth and specific root length. Linking changes of root traits with intercropping effects aboveground helps understand yield advantages in diverse agroecosystem. In general, a cereal species with strong phenotypic plasticity intercropped with a legume species with strong physiological plasticity can maximize the yield advantage of intercropping.

opencc-by-4.0Apr 2022View details →

FUNCTIONAL ANALYSIS OF GENES FOR REPRODUCTIVE TRAITS IN PIGS: FROM GWAS TO POST-GWAS

Reproductive traits, such as number of teats, uniformity and litter size, are essential for animal breeding programs due to the importance for the production chain, since they influence the maternal ability of sow and can affect the number of weaned piglets. Our objective was to identify candidate genes associated with reproductive traits in pigs, using GWAS data, from a systematic review combined with sequencing data, to build networks of biological processes and Gene-TFs (transcription factors networks from the identified genes in order to highlight the most candidate genes for litter size, uniformity and number of teats. In the systematic review only peer-reviewed articles were used, with descriptors related to the evaluated traits, and selected based on eligibility criteria. Fourteen papers were selected and classified into groups for functional analysis of gene networks with 2077 candidate genes identified. After combining with the list of genes presenting known structural variants in the 5'UTR and/or coding region, 306 genes remained to be used to build the networks of biological processes and TFs gene networks, highlighting processes associated with litter size (e.g., ionotropic glutamate receptor signaling pathway and blastocyte growth) and teats number (e.g., growth hormone receptor, regulation of the BMP - Bone Morphogenetic Proteins signaling pathway and blood vessel proliferation). Three most candidate genes for litter size trait (GRID2and PALB2) and six most candidate genes (GHR, IFT80, FSTL3, SKOR1, SMURF1 and AKT3) for teats number were prioritized. TF associated with candidate genes were also identified for litter size (PALB2 and GRID2) and teat number (RIN, LTBP2 and COL6A6). Thus, it is suggested that the genes and TFs presented in this study may play an important role in the traits studied, being important for genetic studies and animal breeding. The highlighted genes may bring new considerations to the current knowledge of the genetic architecture of these traits, since the markers associated with these genes can be assigned higher weights in genomic selection and validated in specific populations.

opencc-by-4.0Jan 2022View details →

Organisation of gene programs revealed by unsupervised analysis of diverse gene-trait associations

Data used for manuscript 'Organisation of gene programs revealed by unsupervised analysis of diverse gene-trait associations'.

opencc-zeroDec 2021View details →

Data from: Contrasting climate sensitivity of Pinus cembra tree-ring traits in the Carpathians

High elevation ecosystems are one of the most sensitive to climate change. The analysis of growth and xylem structure of trees from marginal populations, especially the ones growing at the treeline, could provide early-warning signs to better understand species-specific responses to future climate conditions. In this study, we combined classical dendrochronology with wood density and anatomical measurements to investigate the climate sensitivity of Pinus cembra L., a typical European high-elevation tree species distributed in isolated patches in the Carpathians. Samples were collected from the Retezat Mountains, South-Western Romania. We analyzed ring-width (TRW), maximum density (MXD), xylem anatomical traits (cell number per ring (CNo), cell density (CD), conduit area (CA), and cell-wall thickness (CWT)) time series, split into ring sectors and assessed the relationships with monthly and daily climate records over the last century (1901-2015). The analysis showed a strong dependency of TRW on CNo and MXD on CWT. Summer temperature positively correlated with MXD and CWT (monthly correlation (r) were 0.65 and 0.48 respectively) from the early- to late-wood but not TRW (r=0.22). CA positively correlated with water availability (r=0.37) and negatively correlated with temperature (r=-0.39). This study improves our general understanding of the climate-growth relationships of a European high-elevation tree species and the results could be considered for forecasting population dynamics on projected changes in climate.

Graminoids vary in functional traits, carbon dioxide and methane fluxes in a restored peatland: implications for modeling carbon storage

1. One metric of peatland restoration success is the re-establishment of a carbon sink, yet considerable uncertainty remains around the timescale of carbon sink trajectories. Conditions post-restoration may promote the establishment of vascular plants such as graminoids, often at greater density than would be found in undisturbed peatlands, with consequences for carbon storage. Although graminoid species are often considered as a single plant functional type (PFT) in land-atmosphere models, our understanding of functional variation among graminoid species is limited, particularly in a restoration context. 2. We used a traits-based approach to evaluate graminoid functional variation and to assess whether different graminoid species should be considered a single PFT or multiple types. We tested hypotheses that greenhouse gas fluxes (CO2, CH4) would vary due to differences in plant traits among five graminoid species in a restored peatland in central Alberta, Canada. We further hypothesized that species would form two functionally distinct groupings based on taxonomy (grass, sedge). 3. Differences in gas fluxes among species were primarily driven by variation in leaf physiology related to photosynthetic efficiency and resource-use, and secondarily by plant size. Multivariate analyses did not reveal distinct functional groupings based on taxonomy or environmental preferences. Rather, we identified functional groups defined by plant traits and carbon fluxes that are consistent with ecological strategies related to differences in growth rate, resource-acquisition, and leaf economics, representing plants with either a strategy to grow quickly and invest in resource capture or to prioritize structural investment and resource conservation. These functional groups displayed larger average carbon fluxes compared to graminoid PFTs currently used in modeling. 4. Existing PFT designations in peatland models may be more appropriate for pristine or high-latitude systems than those under restoration. Although replacing PFTs with plant traits remains a challenge in peatlands, traits related to leaf physiology and growth rate strategies offer a promising avenue for future applications.

Life-history traits modulate the influence of environmental stressors on biodiversity: the case of fireflies, climate, and artificial light at night

Aim Artificial light at night (ALAN) is an unprecedented stressor recently introduced in the abiotic milieu of natural landscapes. As such, understanding how ALAN and other natural stressors act in concert to shape the spatial distribution of biodiversity is a core goal in conservation ecology. Here, we aim at understanding how ALAN and climate interact with life-history traits and courtship signalling systems to dictate the composition of firefly communities in a global biodiversity hotspot. Location An extensive elevational gradient in the Atlantic Rainforest (Brazil) currently known as the hottest hotspot of fireflies on Earth. Methods We used multivariate species distribution models to understand how species traits and courtship signalling systems interact with climate and ALAN to determine species abundances within firefly communities. We also investigated how species-specific responses to climate and ALAN scale up to determine compositional changes in firefly communities along the elevational gradient. Results We found that climate shapes communities by filtering species according to their body size and trophic position. ALAN dictates the dominant courtship signalling system within communities by affecting the abundance of species that use bioluminescence or a combination of bioluminescence and pheromones in courtship. We also found that associations between beta-diversity and ALAN were non-stationary, being higher in regions under low levels of light pollution. This suggests that even incipient increases in ALAN within protected areas can yield fast changes in the composition of firefly communities. Main Conclusions Firefly responses to climate and ALAN are modulated by traits associated with different facets of their life histories. Given the alarming changes in both stressors predicted for the foreseeable future, our findings indicate that firefly communities are vulnerable to compositional changes even within protected areas. --