Find research datasets worth reusing

opencc-zeroJun 2022View details →

Trait coordination in boreal mosses reveals a bryophyte economics spectrum

1. The study of plant trait spectra and their association with trade-offs in resource use strategy has greatly advanced our understanding of vascular plant function, yet trait spectra remain poorly studied in bryophytes, particularly outside of the Sphagnum genus. Here, we measured 25 traits related to carbon, nutrient, and water conservation in 60 moss canopies (each dominated by one of 15 moss species) across diverse boreal forest habitats, and used bi-variate correlations and multi-variate analyses to assess trait coordination and trait spectra. 2. We found substantial trait coordination along a main principal components axis driven by trade-offs in carbon, nutrient, and water conservation strategies. Along this trait spectrum, traits varied from resource-acquisitive at one end (e.g., high maximum photosynthetic capacity, high tissue nitrogen content, low water holding capacity) to resource-conservative at the other end, in line with resource economics theory. 3. Traits related to carbon turnover (photosynthesis and respiration rates, litter decomposability) were positively related to nitrogen content and to desiccation rates, in line with global trait spectra in vascular plants. However, architectural traits of the moss shoots and of the moss canopy were generally unrelated to the main axis of trait variation and formed a secondary axis of trait variation, contrary to what is observed for vascular plants. 4. Resource-conservative trait spectra dominated in moss canopies from open and wet habitats (i.e., mires), indicating that high irradiance and possibly high moisture fluctuation induce a resource-conservative trait strategy in mosses. 5. Synthesis. Our work suggests that trait relationships that are well established for vascular plants can be extended for bryophytes as well. Bryophyte trait spectra can be powerful tools to improve our understanding of ecosystem processes in moss-dominated ecosystems, such as boreal or arctic environments, where bryophyte communities exert strong control on nutrient and carbon cycling.

Complex floral traits shape pollinator attraction to ornamental plants

Background and Aims Ornamental flowering plant species are often used in managed greenspaces to attract and support pollinator populations. In natural systems, selection by pollinators is hypothesized to result in convergent multimodal floral phenotypes that are more attractive to specific pollinator taxa. In contrast, ornamental cultivars are bred via artificial selection by humans, and exhibit diverse and distinct phenotypes. Despite their prevalence in managed habitats, the influence of cultivar phenotypic variation on plant attractiveness to pollinator taxa is not well resolved. Methods We used a combination of field and behavioural assays to evaluate how variation in floral visual, chemical and nutritional traits impacted overall attractiveness and visitation by pollinator taxonomic groups and bee species to 25 cultivars of five herbaceous perennial ornamental plant genera. Key results Despite significant phenotypic variation, cultivars tended to attract a broad range of pollinator species. Nonetheless, at the level of insect order (bee, fly, butterfly, beetle), attraction was generally modulated by traits consistent with the pollination syndrome hypothesis. At the level of bee species, the relative influence of traits on visitation varied across plant genera, with some floral phenotypes leading to a broadening of the visitor community, and others leading to exclusion of visitation by certain bee species. Conclusions Our results demonstrate how pollinator choice is mediated by complex multimodal floral signals. Importantly, the traits that had the greatest and most consistent effect on regulating pollinator attraction were those that are commonly selected for in cultivar development. Though variation among cultivars in floral traits may limit the pollinator community by excluding certain species, it may also encourage interactions with generalist taxa to support pollinator diversity in managed landscapes.

Trait shifts in bird communities from primary forest to human settlements in Mexican seasonal forests: Are there ruderal birds?

Agriculture, cattle grazing, and human settlements negatively affect bird biodiversity, driving the loss of ecologically specialized species and favoring the dominance of generalists. Because ecological pressures define organisms' success by acting on their intrinsic traits, biodiversity loss due to anthropization might cause directional trait shifts. Here, we use a trait-based approach to find empirical evidence of trait-shifts in bird communities across an anthropization gradient in seasonal forests in central Mexico. We performed point-count bird surveys within a region of tropical deciduous and seasonal oak forests considering three degrees of anthropization: primary forest, secondary growth, and human settlements. A multivariate analysis (PCA) showed similar trait-covariation patterns for both forest types; in the anthropized habitat the bird communities exhibited shorter life-cycles, higher fecundity, and broader ecological niches (diet, foraging habitat, and nesting resources) than those in the primary forests. Our finding of directional trait shifts resembles Evolutionary Ecological Strategies Theory (EES) predictions for successful organisms within highly disturbed anthropized habitats, which are known as a "ruderal adaptative strategy" in the EES framework. The use of trait-based approaches could improve ecological generalizations in bird communities, leading to a better understanding of avian biodiversity's responses to anthropization.

opencc-by-4.0Jul 2022View details →

zenodo36/100

Age and phenology control photosynthesis and leaf traits in the understory woody species, Rhamnus cathartica and Prunus serotina

Dataset contains leaf physiological variables and leaf traits from Rhamnus cathartica (buckthorn) and Prunus serotina (Black cherry) measured in Summer 2019 at Macalester College's Ordway Field Station. All data were collected on understory individuals from 4 sites within the forest in late May and early July, 2019. We sampled from 'tree' individuals and seedlings of both species. All methods and measurement protocols are published in Heskel et al. 2022 in AoB-PLANTS, currently in revision. Data includes:  Vcmax (umol m2-s-1) Jmax (umol m2-s-1) Fv/Fm (no units) Leaf Stomatal Density (stomata mm-2) Dark respiration (umol m2-s-1) Asat (umol m2-s-1) A400 (umol m2-s-1) Carbon Gain Efficiency (CGE, no units) CGE_400 (CGE at 400 PAR, no units) Leaf Mass per Are (LMA, g m-2)

Divergent trait responses to nitrogen addition in tall and short species

Asymmetrical light competition and direct detrimental effect of nitrogen have been proposed as two main mechanisms driving species richness declines following nitrogen (N) addition. N addition is also known to alter functional trait composition towards increased dominance of tall and fast-growing species. However, whether trait changes vary between species and, in particular, how the traits of tall and short species respond to N addition has rarely been studied. Understanding whether different trait changes occur for tall and short species would provide insight into mechanisms underlying N addition effects. Based on a long-term N addition experiment, we measured the natural height of 44 plant species and the photosynthetic active radiation (PAR) at seven heights in the vegetation and identified a clear stratification of the plant community into tall species (>30cm tall), which experienced high light conditions, and short species that grew under the canopy. We also measured four functional traits, including maximum plant height, specific leaf area, leaf dry matter content and leaf thickness, on 35 species that occurred in fertilized and unfertilized plots. Structural equation modelling revealed that nitrogen (N) addition significantly reduced species richness by enhancing light asymmetry and had no direct effects, suggesting that N detrimental effects are negligible in our system. Consistent with this, we found different responses of traits and diversity for the tall and short species. Specifically, N addition reduced the number of short species but increased the number of tall species. In addition, specific leaf area increased, and leaf dry matter content decreased, for short species only, suggesting that they shifted to a fast growth strategy to cope with lower light levels. In contrast, tall species increased their height further to capture more light at the top of the canopy. Synthesis. The divergent trait responses observed for tall and short species show that although certain traits, like height and leaf traits, show correlated responses at the whole community level, these correlations may not be consistent across all species. Together, our results highlight that light competition is the main mechanism driving species loss following N addition gradient.

Floral traits mediate pollinator disease transmission

Plants modulate multitrophic ecological interactions, and variation in plant traits can affect these interactions. Pollinators are exposed to pathogens at flowers and acquire or transmit pathogens at different rates on different plant species, but the traits mediating those interactions are almost entirely unknown. We experimentally manipulated five plant traits that span scales including flower, inflorescence, and plant, to determine their effects on pathogen transmission between foraging bees. Specifically, we manipulated two morphological traits (corolla lip length and flower orientation within an inflorescence) and three resource distribution traits (inflorescence nectar, plant patch nectar and plant aggregation) in tents to test how plant traits affect bee pathogen transmission. We also quantified foraging behavior and fecal deposition patterns as potential mechanisms driving differences in transmission, and assessed trait manipulation consequences for bee reproduction. We found that pathogen transmission was reduced when we trimmed the corolla lip, evenly dispersed nectar distribution within an inflorescence, or aggregated plants in space. Some traits also affected bee reproduction; tents with trimmed corollas had more larval production than control tents, and tents with evenly distributed nectar across plant patches had more larval production than tents with clumped resources. Thus, some trait manipulations both reduced transmission and increased bee microcolony reproduction, although our design does not allow us to discern whether these are related or separate effects. Taken together, our results demonstrate causal effects of several floral traits on pathogen transmission and pollinator reproduction, indicating the importance of intraspecific plant trait variation for pollinator health and population dynamics.

Bamboo climatic tolerances are decoupled from leaf functional traits across an Andean elevation gradient

Widespread changes in temperature and precipitation patterns present plant species with new and combined stresses that affect their performance and distribution. Functional traits are indicators of plant resource use-acquisition strategies and thus they are commonly used to understand the geographic distributions of plant species and species' potential responses to climate change. To date, most studies have targeted a few easy-to-measure leaf traits even though other traits, such as climatic tolerances, could provide valuable information directly related with species' current and future distributions. Here, we measured both leaf functional traits and indices of physiological tolerance to heat (T50) and drought (Cell Membrane Stability) in 28 woody bamboo populations from 22 narrow-ranged species along a > 3000 m elevation gradient in the southern Peruvian Andes. We found that bamboo leaf functional traits remain fairly constant with a combination indicative of an acquisitive strategy (low leaf mass area and high nitrogen per mass) along the elevation gradient, despite drastic changes in environment and fast species turnover. Heat and drought tolerances of bamboos varied widely along the gradient and were negatively correlated to each other. Drought tolerance of bamboo populations was positively related with elevation and with precipitation seasonality while heat tolerance decreased at higher, colder elevations. When analyzed for individuals within each species or for individuals within each elevation, the two metrics of climatic tolerances did not show a consistent relationship, contrasting with the expectation of a potential trade-off between heat and drought tolerance. We also found that the measured leaf functional traits were not good predictors of climatic tolerances. Our results illustrate the diversity and complexity of the relationships between functional strategies and environmental gradients and highlight the limitations of using basic (i.e., "soft") leaf traits to understand plant distributions and climatic tolerances.

Clonal functional traits favor the invasive success of alien plants into native communities

Functional traits are frequently proposed to determine the invasiveness of alien species. However, few empirical studies have directly manipulated functional traits and tested their importance in the invasion success of alien species into native plant communities, particularly under global change. We manipulated clonal integration (a key clonal functional trait) of four alien clonal plants by severing inter-ramet connections or keeping them intact, and simulated their invasion into native plant communities with two levels of species diversity, population density and nutrient availability. High community diversity and density impeded the invasion success of the alien clonal plants. Clonal integration of the alien plants promoted their invasion success, particularly in the low-density communities associated with low species diversity or nutrient addition, which resulted in a negative correlation between performance of alien plants and native communities, as expected under global change. Thus, clonal integration can favor the invasion success of alien clonal plants into degraded resident communities with a high degree of disturbance and eutrophication. Our findings confirm the role of clonal functional traits in facilitating alien plant invasions into native plant communities, and suggest that clonal functional traits should be considered to efficiently restore degraded communities heavily invaded by alien clonal plants.

zenodo36/100

Influence of water limitation and provenance on reproductive traits in a common garden of Frangula alnus

Files <ul> <li>zenodofalnusmotherplants.xlsx: data from mother plants from which berries were picked in 2020</li> <li>zenodofalnusberrystone.xlsx: details on the berries and stones</li> </ul> Abstract of related paper Drought periods during the growing season will increase and intensify in Western Europe due to climate change. To better understand the consequences for woody perennials, we restricted watering of potted cuttings of Frangula alnus Mill. in a common garden setting in Belgium during the growing season of 2020. We focused on the responses of three provenances (Belgian, Italian and Swedish) for several reproductive traits in the year of the water limitation. F. alnus can blossom on current season's growth and can therefore produce ripened berries continuously during several months. The total berry count over the whole growing season was much lower in the water-limited plants, independent of the provenance. The Belgian provenance produced more ripened berries in total than the Italian and Swedish provenances, both in the water-limited as in the control plants. Maximum berry production occurred in July. The control plants from the Belgian and Italian provenances displayed a second lower maximum in August. Mainly the Swedish provenance displayed a clear advancement of the maximum berry production among the water limited plants in comparison to the control plants. Slight differences were detected in the average stone count per berry and in the average stone weight over time, with both traits displaying a single maximum. The Swedish provenance displayed the highest average stone count per berry and the Belgian provenance had the lightest average stone weight, both likely attributable to local adaptation. Remarkably, both stone traits were not affected by the water limitation. Results are discussed in the face of several drought response mechanisms including drought escape, drought avoidance, compensation growth, growth/reproduction trade-off and seed size/weight trade-off.

Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability

The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection since drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths we show that the presence of one or two copies of the yellow allele affects several life-history traits. Reproductive output of both males and females, and female mating success are negatively affected by two copies of the yellow allele. Females carrying one yellow allele (i.e. Wy) have higher fertility, hatching success, and offspring survival than either homozygote, thus leading to strong heterozygote advantage. Our results indicate strong female contribution especially at the postcopulatory stage in maintaining the color polymorphism. The interplay between heterozygote advantage, yellow allele pleiotropic effect and morph-specific predation pressure may exert balancing selection on the color locus, suggesting that color polymorphism may be maintained through complex interactions between natural and sexual selection.

Data from: Environmental filtering of macroinvertebrate traits influences ecosystem functioning in a large river floodplain

The Biodiversity-Ecosystem Function hypothesis postulates that higher biodiversity is correlated with faster ecosystem process rates and increased ecosystem stability in fluctuating environments. Exhibiting high spatio-temporal habitat diversity, floodplains are highly productive ecosystems, supporting communities that are naturally resilient and highly diverse. We examined linkages among floodplain wetland habitats, invertebrate communities and their associated traits, and ecosystem function across 60 sites within the floodplain wetlands of the lower Wolastoq | Saint John River, New Brunswick, using structural equation modelling and Threshold Indicator Taxa ANalysis (TITAN2). We identified key environmental filters structuring invertebrate communities, by linking increased niche differentiation through shoreline change, flood pulse dynamics, and macrophyte bed complexity with increased taxa and functional diversity. Examination of traits linked to ecosystem functions revealed that more resilient wetlands with balance between primary productivity and decomposition as carbon sources were associated with greater functional evenness and richness, while habitat patches with elevated decomposition rates had lower functional richness, reflecting a simplified, more disturbed habitat. While our more complex overarching SEM model was ultimately compromised by an overspecified number of pathways, our results nevertheless are indicative of a divergence between wetland and riverine ecosystems in their relationships linking biodiversity and ecosystem function, illustrating how to define ecosystem health in wetland habitats, and demonstrating how critical functions support healthy wetland habitats by providing increased resilience to disturbance.

opencc-by-4.0Jul 2022View details →

zenodo36/100

Data_Changes in Tree Diversity, Structure and Functional Trait Identity Drive Biomass Increase along Elevational Gradients in Subtropical Forests of Southern China

In this article "Changes in Tree Diversity, Structure and Functional Trait Identity Drive Biomass Increase along Elevational Gradients in Subtropical Forests of Southern China", these files contain community inventory data collected at our three study sites.

opencc-zeroDec 2021View details →

Phylogenomics shows unique traits in Noctilucales are derived rather than ancestral

Dinoflagellates are a diverse group of protists that possess many unique traits. These include (but are not limited to) expansive genomes packaged into permanently condensed chromosomes, photosynthetic or cryptic plastids acquired vertically or horizontally in serial endosymbioses, and a ruffle-like transverse flagellum attached along its length to the cell. When reconstructing character evolution, early branching lineages with unusual features that distinguish them from the rest of the group have proven useful for inferring ancestral states. The Noctilucales are one such lineage, possessing relaxed chromosomes in some life stages and a trailing, thread-like transverse flagellum. However, most of the cellular and molecular data for the entire group come from a single cultured species, Noctiluca scintillans, and because its phylogenetic position is unresolved, it remains unclear if these traits are ancestral or derived. Here, we use single cell transcriptomics to characterize three diverse Noctilucales genera: Spatulodinium, Kofoidinium, and a new lineage, Fabadinium gen. nov. We also provide transcriptomes for undescribed species in Amphidinium and Abediniales, critical taxa for clarifying the phylogenetic position of Noctilucales. Phylogenomic analyses suggest that the Noctilucales are sister to Amphidinium rather than an independent branch outside the core dinoflagellates. This topology is consistent with observations of shared characteristics between some members of Noctilucales and Amphidinium and provides the most compelling evidence to date that the unusual traits within this group are derived rather than ancestral. We also confirm that Spatulodinium plastids are photosynthetic and of ancestral origin, and show that all non-photosynthetic Noctilucales retain plastid genes indicating a cryptic organelle.

Quantitative trait loci mapping in cichlid fishes: Aulonocara koningsi x Metriaclima mbenjii and Labidochromis caeruleus x Labeotropheus trewavasae

Since the time of Darwin, biologists have sought to understand the evolution and origins of phenotypic variation. To understand the genetic and molecular sources of morphological differences, we capitalize on the cichlid fish system. Cichlids of the East African Rift Lakes have undergone an extensive adaptive radiation, including variation in body shape, head shape, and pigmentation. These morphological differences are often intimately linked to the ecology and behavior of these animals. Here, we investigate the genetic basis of these phenotypes using quantitative trait loci (QTL) mapping using four genera of Lake Malawi cichlids and two F2 hybrid populations. The first hybrid cross is between Aulonocara koningsi, which lives in the open sandy region and feeds insects from the open sand, and Metriaclima mbenjii, an omnivore rock-dwelling fish. The second cross is between Labidochromis caeruleus, a suction-feeding insectivore that swims continuously searching for prey, and Labeotropheus trewavasae, which feeds by biting or scraping attached algae from the rocks in its benthic habitat. Such work can provide insights into the molecular basis of phenotypic adaptation, the genetic architecture of morphology, and the evolution of cichlid fishes.

Ecology and evolution of competitive trait variation in natural phytoplankton communities under selection

Competition for limiting resources is a major force structuring ecological communities. Species minimum resource requirements (R*s) can predict competitive outcomes and evolve under selection in simple communities under controlled conditions. However, whether R*s predict competitive outcomes or demonstrate adaptive evolution in naturally complex communities is unknown. We subjected natural phytoplankton communities to three types of resource limitation (nitrogen, phosphorus, light) in outdoor mesocosms over ten weeks. We examined the community composition weekly and isolated 21 phytoplankton strains from seven species to quantify responses to selection of R* for these resources. We investigated evolutionary change in R*s in the dominant species, Desmodesmus armatus. R*s were good predictors of species changes in relative abundance, though this was largely driven by the success of D. armatus across several treatments. This species also demonstrated evolutionary change in R*s under resource limitation, supporting the potential for adaptive trait change to modify competitive outcomes in natural communities.

Diaspore traits specialized to animal adhesion and sea current dispersal are positively associated with the naturalization of European plants across the World

Understanding what drives non-native species naturalization (the establishment of a self-sustainable population outside its native range) is a central question in invasion science. Plants' capacity for long distance dispersal (LDD) is likely to influence the spread and naturalization of non-native species differently according to their introduction pathways. These pathways include intentional introductions (for economic use, e.g. for agriculture), unintentional introductions (e.g. seed contaminants), plant dispersal via human infrastructures (e.g. roads), and plant spread from an adjacent region where the species was previously introduced. Herein, we tested the relationship between sets of LDD traits (syndromes) of 10,308 European plant species and their global naturalization incidence (i.e. whether a species has become naturalized or not) and extent (i.e. the number of regions where a species has become naturalized) using the most comprehensive database of naturalized plants worldwide (GloNAF). Diaspore traits allowed the identification of four traditional LDD syndromes, namely those with specializations for dispersal by: wind (anemochorous), animal ingestion (endozoochorous), attached to animals (epizoochorous), and sea currents (thalassochorous). These evolutionary specializations have been historically interpreted by biologists even though actual dispersal is not always related to diaspore syndromes. We found that while epizoochorous and thalassochorous traits are positively associated with global plant naturalization incidence, anemochorous and endozoochorous traits show a negative relationship. Species´ residence time outside their native range, their economic use and presence of epizoochorous traits (such as hooks, hairs and adhesive substances) are positively associated with global naturalization extent. Furthermore, we found that plants' economic use reduces the influence of LDD syndromes on the naturalization incidence of intentionally introduced plants. While the success of non-native plants is influenced by a broad array of species- and context-specific factors, LDD syndromes play an important role in this context depending on the economic use of plants.

Avoiding growing pains in reproductive trait databases: the curse of dimensionality

Aim: Reproductive output features prominently in many trait databases, but the metrics describing it vary and are often untethered to temporal- and volumetric-dimensions (e.g., fecundity-per-bout). Using such ambiguous reproductive measures to make broadscale comparisons across taxonomic groups will only be meaningful if they show a 1:1 relationship with a reproductive measure that explicitly includes both a volumetric and temporal component (i.e., reproductive mass-per-year). We sought to map the prevalence of ambiguous and explicit reproductive measures across taxa, and explore their relationships with one another to determine the cross-compatibility and utility of reproductive metrics in trait databases. Location: Global. Time period: 1990-2021. Major taxa studied: We searched for reproductive measures across all Metazoa, and identified 19,785 Chordata species, along with 440 species of Arthropoda, Cnidaria, or Mollusca. Methods: We included 37 databases from which we summarised the commonality of reproductive metrics across taxonomic groups. We also quantified scaling relationships between ambiguous reproductive traits (fecundity-per-bout, fecundity-per-year and reproductive mass-per-bout) and an explicit measure (reproductive mass per-year) to assess their cross-compatibility. Results: Most species were missing at least one temporal or volumetric dimension of reproductive output, such that reproductive mass-per-year could be reconstructed for only 4,786 vertebrate species. Ambiguous reproductive measures were poor predictors of reproductive mass-per-year – in no instance did these measures scale at 1:1. Main Conclusions: Ambiguous measures systematically misestimate reproductive mass-per-year. Until more data are collected, we suggest authors use the clade-specific scaling relationships provided here to convert ambiguous reproductive measures to reproductive mass-per-year.

Chronic browsing by an introduced mammalian herbivore in a tropical island alters species composition and functional traits of forest understory plant communities

Mammalian herbivores have large-scale impacts on vegetation, altering structure and species composition, especially in tropical grasslands and savannas. However, there is limited understanding of the potential impacts of mammalian herbivores in tropical wet forests, where they are typically less abundant. We investigated the effects of an introduced mammalian herbivore chital (Axis axis) on vegetation structure, composition and leaf functional traits of tropical evergreen forests of the Andaman Islands, India. Across seven islands, representing a gradient of herbivore densities, increasing chital presence was associated with decreased understory richness, understory density and adult tree richness, but was not related to adult tree density or size class distributions. We also found a significant decrease in community-level leaf palatability traits (specific leaf area decreased and leaf thickness increased) with increasing chital habitat use. This community-level shift in leaf trait values was better explained by intra-specific variation in leaf traits across islands rather than changes in species composition. In summary, we show persistent long-term impacts of an introduced mammalian herbivore on understory tropical tree communities although there is little impact on adult tree communities. Our results also show that functional traits of species can be altered in response to novel herbivory, even at herbivore densities where there are no detectable impacts on adult forest structure or composition. Such altered functional traits may potentially alter ecosystem functioning in these forests even without changes in vegetation structure.

Community-wide trait adaptation, but not plasticity, explain ant community structure in extreme environments

1. Quantifying trait-environment associations can help elucidate the processes underpinning the structure of species assemblages. However, most work has focused on trait variation across rather than within species, meaning that processes operating at the intraspecific levels cannot be detected. Incorporating intraspecific trait variation in community-wide analyses can provide valuable insights about the role of morphological adaptation and plasticity on species persistence and the composition of ecological communities. 2. Here, we assessed geographic variation in the direction (i.e., adaptation) and strength of selection, and the magnitude of plasticity, by examining community-wide trait variation in ant communities along an environmental gradient spanning 9° latitude in Quebec, Canada. Specifically, we measured 9 morphological traits related to foraging strategies, resource use and thermal regulation at 20 locations across temperate and boreal forests. We then examined how the mean and variance of these traits varied along temperature and precipitation gradients. Moreover, we examined how these trait-environment relationships varied across levels of organization, from individual workers (intraspecific) to colonies (intraspecific) and species (interspecific). 3. We observed changes in mean trait values along environmental gradients, but very little change in variance. Specifically, we observed a decrease in the mean length of antennae and an increase in the mean eye length from mild (warm and wet) to more extreme environments (cold and dry). These shifts in trait means were mostly coordinated across organizational levels (i.e., worker, colony, and species). We also observed a general increase in trait variance from mild to extreme environments, but only at the species level. 4. Our findings suggest that stressful environmental conditions exert a strong selection pressure on ant morphology causing shifts in optimal trait values. These adaptations may enable persistence at the northern edge of the boreal forest and therefore influence the composition of these ant communities. Specifically, ants with large eyes and short antennae are overrepresented at the transition zone between the boreal forest and the tundra, possibly representing an adaptation to these more open habitats. Our study demonstrates that combining spatial and community-wide intraspecific functional trait data provides a promising way forward to gain new insights on trait adaptations and processes underpinning community structure along environmental gradients.

Connectivity among thermal habitats buffers the effects of warm climate on life-history traits and population dynamics

1. Contemporary climate change affects population dynamics, but its influence varies with landscape structure. It is still unclear whether landscape fragmentation buffers or enhances the effects of climate on population size and on the age and body size of individuals composing these populations. 2. This study aims to investigate the impacts of warm climates on lizard life-history traits and population dynamics in habitats varying in their connectivity. 3. We monitored common lizard (Zootoca vivipara) populations for three years in an experimental system in which both climatic conditions and connectivity among habitats were simultaneously manipulated. We considered two climatic treatments (i.e., present-day climate and warm climate (+1.4°C than present-day climate)) and two connectivity treatments (i.e., a connected treatment in which individuals could move from one climate to the other and an isolated treatment in which movement between climates was not possible). We monitored survival, reproduction, growth, dispersal, age and body size of each individual in the system as well as population density through time. 4. We found that the influence of warm climates on the life-history traits and population dynamics depended on the connectivity among thermal habitats. Populations in warm climates were i) composed of younger individuals only when isolated; ii) larger in population size only in connected habitats; and iii) composed of larger age-specific individuals independently of the landscape configuration. The connectivity among habitats altered population responses to climate warming likely through asymmetries in the flow and phenotype of dispersers between thermal habitats. 5. Our results demonstrate that landscape fragmentation can drastically change the dynamics and persistence of populations facing climate change.