Variation In Life-history Traits Research Articles

Variation and plasticity in life-history traits and fitness of wild Arabidopsis thaliana populations are not related to their genotypic and ecological diversity

BackgroundDespite its implications for population dynamics and evolution, the relationship between genetic and phenotypic variation in wild populations remains unclear. Here, we estimated variation and plasticity in life-history traits and fitness of the annual plant Arabidopsis thaliana in two common garden experiments that differed in environmental conditions. We used up to 306 maternal inbred lines from six Iberian populations characterized by low and high genotypic (based on whole-genome sequences) and ecological (vegetation type) diversity.ResultsLow and high genotypic and ecological diversity was found in edge and core Iberian environments, respectively. Given that selection is expected to be stronger in edge environments and that ecological diversity may enhance both phenotypic variation and plasticity, we expected genotypic diversity to be positively associated with phenotypic variation and plasticity. However, maternal lines, irrespective of the genotypic and ecological diversity of their population of origin, exhibited a substantial amount of phenotypic variation and plasticity for all traits. Furthermore, all populations harbored maternal lines with canalization (robustness) or sensitivity in response to harsher environmental conditions in one of the two experiments.ConclusionsOverall, we conclude that the environmental attributes of each population probably determine their genotypic diversity, but all populations maintain substantial phenotypic variation and plasticity for all traits, which represents an asset to endure in changing environments.

Variation in amphibian maturation rates influences population vulnerability to disease‐induced declines

AbstractUnderstanding factors that influence population‐level responses to emerging threats in declining species is crucial for informed conservation action. In amphibian species impacted by the chytrid fungus (Batrachochytrium dendrobatidis), a pathogen that has caused amphibian declines globally, a commonly reported pattern is that more severe population declines tend to occur at higher elevations. Previous research has suggested that this pattern could be driven by reduced environmental suitability for chytrid fungus at lower elevations. However, delayed amphibian maturation, which is common in cold, high elevation populations, could also increase vulnerability to population decline. Here, we tackle this key knowledge gap, focusing on the critically endangered corroboree frogs (Pseudophryne corroboree and P. pengilleyi), which have experienced a pattern of extirpation at higher elevations, with remnant populations persisting at lower elevations. First, we quantify the age structure of two extant low elevation P. pengilleyi populations and museum specimens (both species) collected before the emergence of chytrid fungus in Australia. Male age to maturation varied from 1 to 3 years, with the extant population with higher chytrid prevalence displaying severe age structure truncation. Second, we use population simulations to calculate elasticity values under a range of scenarios with varying ages to maturation and chytrid‐associated mortality. When the population growth rate was fixed at 1, adult survival became increasingly important as age to maturation increases, particularly under a scenario of high chytrid‐associated mortality. Our simulation results indicate that delayed maturation could be a previously underappreciated factor associated with an increased risk of amphibian population decline and that earlier maturation could contribute to population persistence. Our study highlights the importance of examining variation in life history traits to better understand population‐level responses to novel threats and guide the development of appropriate conservation actions.

Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre

Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.

Plasticity, symbionts and niche construction interact in shaping dung beetle development and evolution.

Developmental plasticity is an important product of evolutionary processes, allowing organisms to maintain high fitness in the face of environmental perturbations. Once evolved, plasticity also has the potential to influence subsequent evolutionary outcomes, for example, by shaping phenotypic variation visible to selection and facilitating the emergence of novel trait variants. Furthermore, organisms may not just respond to environmental conditions through plasticity but may also actively modify the abiotic and (sym)biotic environments to which they themselves respond, causing plasticity to interact in complex ways with niche construction. Here, we explore developmental mechanisms and evolutionary consequences of plasticity in horned dung beetles. First, we discuss how post-invasion evolution of plasticity in an introduced Onthophagus species facilitated rapid range expansion and concurrent local adaptation of life history and morphology to novel climatic conditions. Second, we discuss how, in addition to plastically responding to variation in nutritional conditions, dung beetles engage in behaviors that modify the environment that they themselves respond to during later development. We document that these environment-modifying behaviors mask heritable variation for life history traits within populations, thereby shielding genetic variants from selection. Such cryptic genetic variation may be released and become selectable when these behaviors are compromised. Together, this work documents the complex interactions between plasticity, symbionts and niche construction, and highlights the usefulness of an integrative Eco-Evo-Devo framework to study the varied mechanisms and consequences of plasticity in development and evolution.

Investigating structural variant, indel and single nucleotide polymorphism differentiation between locally adapted Atlantic salmon populations.

Genomic structural variants (SVs) are now recognized as an integral component of intraspecific polymorphism and are known to contribute to evolutionary processes in various organisms. However, they are inherently difficult to detect and genotype from readily available short-read sequencing data, and therefore remain poorly documented in wild populations. Salmonid species displaying strong interpopulation variability in both life history traits and habitat characteristics, such as Atlantic salmon (Salmo salar), offer a prime context for studying adaptive polymorphism, but the contribution of SVs to fine-scale local adaptation has yet to be explored. Here, we performed a comparative analysis of SVs, single nucleotide polymorphisms (SNPs) and small indels (<50 bp) segregating in the Romaine and Puyjalon salmon, two putatively locally adapted populations inhabiting neighboring rivers (Québec, Canada) and showing pronounced variation in life history traits, namely growth, fecundity, and age at maturity and smoltification. We first catalogued polymorphism using a hybrid SV characterization approach pairing both short- (16X) and long-read sequencing (20X) for variant discovery with graph-based genotyping of SVs across 60 salmon genomes, along with characterization of SNPs and small indels from short reads. We thus identified 115,907 SVs, 8,777,832 SNPs and 1,089,321 short indels, with SVs covering 4.8 times more base pairs than SNPs. All three variant types revealed a highly congruent population structure and similar patterns of F ST and density variation along the genome. Finally, we performed outlier detection and redundancy analysis (RDA) to identify variants of interest in the putative local adaptation of Romaine and Puyjalon salmon. Genes located near these variants were enriched for biological processes related to nervous system function, suggesting that observed variation in traits such as age at smoltification could arise from differences in neural development. This study therefore demonstrates the feasibility of large-scale SV characterization and highlights its relevance for salmonid population genomics.

Unclear relationships between mean survival rate and its environmental variance in vertebrates.

Current environmental changes may increase temporal variability of life history traits of species thus affecting their long-term population growth rate and extinction risk. If there is a general relationship between environmental variances (EVs) and mean annual survival rates of species, that relationship could be used as a guideline for analyses of population growth and extinction risk for populations, where data on EVs are missing. For this purpose, we present a comprehensive compilation of 252 EV estimates from 89 species belonging to five vertebrate taxa (birds, mammals, reptiles, amphibians and fish) covering mean annual survival rates from 0.01 to 0.98. Since variances of survival rates are constrained by their means, particularly for low and high mean survival rates, we assessed whether any observed relationship persisted after applying two types of commonly used variance stabilizing transformations: relativized EVs (observed/mathematical maximum) and logit-scaled EVs. With raw EVs at the arithmetic scale, mean-variance relationships of annual survival rates were hump-shaped with small EVs at low and high mean survival rates and higher (and widely variable) EVs at intermediate mean survival rates. When mean annual survival rates were related to relativized EVs the hump-shaped pattern was less distinct than for raw EVs. When transforming EVs to logit scale the relationship between mean annual survival rates and EVs largely disappeared. The within-species juvenile-adult slopes were mainly positive at low (<0.5) and negative at high (>0.5) mean survival rates for raw and relativized variances while these patterns disappeared when EVs were logit transformed. Uncertainties in how to interpret the results of relativized and logit-scaled EVs, and the observed high variation in EV's for similar mean annual survival rates illustrates that extrapolations of observed EVs and tests of life history drivers of survival-EV relationships need to also acknowledge the large variation in these parameters.

The natural history of luck: A synthesis study of structured population models.

Chance pervades life. In turn, life histories are described by probabilities (e.g. survival and breeding) and averages across individuals (e.g. mean growth rate and age at maturity). In this study, we explored patterns of luck in lifetime outcomes by analysing structured population models for a wide array of plant and animal species. We calculated four response variables: variance and skewness in both lifespan and lifetime reproductive output (LRO), and partitioned them into contributions from different forms of luck. We examined relationships among response variables and a variety of life history traits. We found that variance in lifespan and variance in LRO were positively correlated across taxa, but that variance and skewness were negatively correlated for both lifespan and LRO. The most important life history trait was longevity, which shaped variance and skew in LRO through its effects on variance in lifespan. We found that luck in survival, growth, and fecundity all contributed to variance in LRO, but skew in LRO was overwhelmingly due to survival luck. Rapidly growing populations have larger variances in LRO and lifespan than shrinking populations. Our results indicate that luck-induced genetic drift may be most severe in recovering populations of species with long mature lifespan and high iteroparity.

Variations in life-history traits in exploited and unexploited populations of Perth herring (Nematalosa vlaminghi): evidence for density-dependent growth?

Context Fishing can reduce population biomass, allowing remaining individuals to grow faster and mature earlier because of greater resource availability, which potentially compensates for lost reproductive output over a shortened lifespan resulting from fishing mortality. Aims To compare life-history traits of Nematalosa vlaminghi, a long-lived (20 years), semi-anadromous fish endemic to south-western Australia, in exploited and unexploited populations living in similar environments. Methods Populations were sampled in 2016–2018. Total mortality (Z) was estimated using catch-curve analyses, allowing for annual recruitment variability. Maturation age and length was estimated by logistic regression analysis. Growth curves were fitted to length-at-age data. Key results Compared to the unexploited population, Z was 2.6 times greater, juvenile growth was more than twice as fast, and maturity was attained at least 3 years earlier in the unexploited population. Conclusions Results supported the hypothesis of faster growth in exploited populations because of density-dependent processes. Environmental factors may also have contributed to trait differences between populations. Implications Faster growth and earlier maturation may partly compensate for lost reproductive output in exploited populations, although severe age truncation owing to fishing is still likely to decrease population resilience in this species, irrespective of any compensatory density-dependent processes.

Why we cannot always expect life history strategies to directly inform on sensitivity to environmental change.

Variation in life history traits in animals and plants can often be structured along major axes of life history strategies. The position of a species along these axes can inform on their sensitivity to environmental change. For example, species with slow life histories are found to be less sensitive in their long-term population responses to environmental change than species with fast life histories. This provides a tantalizing link between sets of traits and population responses to change, contained in a highly generalizable theoretical framework. Life history strategies are assumed to reflect the outcome of life history tradeoffs that, by their very nature, act at the individual level. Examples include the tradeoff between current and future reproductive success, and allocating energy into growth versus reproduction. But the importance of such tradeoffs in structuring population-level responses to environmental change remains understudied. We aim to increase our understanding of the link between individual-level life history tradeoffs and the structuring of life history strategies across species, as well as the underlying links to population responses to environmental change. We find that the classical association between lifehistory strategies and population responses to environmental change breaks down when accounting for individual-level tradeoffs and energy allocation. Therefore, projecting population responses to environmental change should not be inferred based only on a limited set of species traits. We summarize our perspective and a way forward in a conceptual framework.

Geographical Variation in Body Size in the Asian Common Toad (Duttaphrynus melanostictus).

The geographic variation in life-history traits of organisms and the mechanisms underlying adaptation are interesting ideas in evolutionary biology. This study investigated age and body size of the Asian common toad (Duttaphrynus melanostictus) among five populations along a geographical gradient. We found that geographical variation in age was non-significant among populations but there was a significant and positive correlation between mean age and body size. Although the body size values at 1043 m are quite different from other sites, after controlling for age effects, there was a significant positive correlation between altitude and body size. Our findings followed the predictions of Bergmann's rule, suggesting that the body size of D. melanostictus is potentially influenced by the low air temperatures at higher altitudes.

A supermatrix phylogeny of the world’s bees (Hymenoptera: Anthophila)

The increasing availability of large molecular phylogenies has provided new opportunities to study the evolution of species traits, their origins and diversification, and biogeography; yet there are limited attempts to synthesise existing phylogenetic information for major insect groups. Bees (Hymenoptera: Anthophila) are a large group of insect pollinators that have a worldwide distribution, and a wide variation in ecology, morphology, and life-history traits, including sociality. For these reasons, as well as their major economic importance as pollinators, numerous molecular phylogenetic studies of family and genus-level relationships have been published, providing an opportunity to assemble a bee ‘tree-of-life’. We used publicly available genetic sequence data, including phylogenomic data, reconciled to a taxonomic database, to produce a concatenated supermatrix phylogeny for the Anthophila comprising 4,586 bee species, representing 23% of species and 82% of genera. At family, subfamily, and tribe levels, support for expected relationships was robust, but between and within some genera relationships remain uncertain. Within families, sampling of genera ranged from 67 to 100% but species coverage was lower (17–41%). Our phylogeny mostly reproduces the relationships found in recent phylogenomic studies with a few exceptions. We provide a summary of these differences and the current state of molecular data available and its gaps. We discuss the advantages and limitations of this bee supermatrix phylogeny (available online at beetreeoflife.org), which may enable new insights into long standing questions about evolutionary drivers in bees, and potentially insects more generally.

Biogeographic history, egg colouration, and habitat selection in Turdus thrushes (Aves: Turdidae)

Despite broad interest and recent experimentation, there is no single ecological model accounting for the adaptive significance of the diversity of avian eggshell colouration. The often blue-green eggs of Turdus thrushes are a charismatic example of this, having long captured cultural and scientific attention. Although the biology and evolutionary history of “true” thrushes is well understood, little is known about correlated evolution between shifts in habitat and eggshell pigmentation, and how these shifts map with Turdus biogeography. We applied phylogenetic comparative methods to assess the evolutionary timing of divergence and variation of life history traits and eggshell colouration and maculation presence in the genus. We found that eggshell colour diversified independently on several occasions in the past 11 million years, with much of the variation occurring within the last 4 million years. The majority of Turdus species lay blue-green eggs and also tend to be sedentary and forest-dwelling. Diet generalist species and species which have transitioned to a forest habitat are more likely to lay white eggs (10% of studied species). In turn, lineages in any habitat were more likely to transition to blue-green eggs. We found that variation in egg colour is increased in some clades, of which two lineages radiated in South America and the East Palearctic, in the past 2–4 million years. These findings provide support for the hypothesis that white eggs are more conspicuous to predators in open environments and that multiple, non-mutually exclusive constraints operate on the adaptive function of avian eggshell colour.

Phylogeny, Ecology, and Gene Families Covariation Shaped the Olfactory Subgenome of Rodents.

Olfactory receptor (OR) genes represent the largest multigenic family in mammalian genomes and encode proteins that bind environmental odorant molecules. The OR repertoire is extremely variable among species and is subject to many gene duplications and losses, which have been linked to ecological adaptations in mammals. Although they have been studied on a broad taxonomic scale (i.e., placental), finer sampling has rarely been explored in order to better capture the mechanisms that drove the evolution of the OR repertoire. Among placental mammals, rodents are well-suited for this task, as they exhibit diverse life history traits, and genomic data are available for most major families and a diverse array of lifestyles. In this study, 53 rodent published genomes were mined for their OR subgenomes. We retrieved more than 85,000 functional and pseudogene OR sequences that were subsequently classified into phylogenetic clusters. Copy number variation among rodents is similar to that of other mammals. Using our OR counts along with comparative phylogenetic approaches, we demonstrated that ecological niches such as diet, period of activity, and a fossorial lifestyle strongly impacted the proportion of OR pseudogenes. Within the OR subgenome, phylogenetic inertia was the main factor explaining the relative variations of the 13 OR gene families. However, a striking exception was a convergent 10-fold expansion of the OR family 14 among the phylogenetically divergent subterranean mole-rat lineages belonging to Bathyergidae and Spalacidae families. This study illustrates how the diversity of the OR repertoire has evolved among rodents, both shaped by selective forces stemming from species life history traits and neutral evolution along the rodent phylogeny.

Comparative transcriptome analysis of two Daphnia galeata genotypes displaying contrasting phenotypic variation induced by fish kairomones in the same environment of the Han River, Korea

BackgroundPhenotypic plasticity is a crucial adaptive mechanism that enables organisms to modify their traits in response to changes in their environment. Predator-induced defenses are an example of phenotypic plasticity observed across a wide range of organisms, from single-celled organisms to vertebrates. In addition to morphology and behavior, these responses also affect life-history traits. The crustacean Daphnia galeata is a suitable model organism for studying predator-induced defenses, as it exhibits life-history traits changes under predation risk. To get a better overview of their phenotypic plasticity under predation stress, we conducted RNA sequencing on the transcriptomes of two Korean Daphnia galeata genotypes, KE1, and KB11, collected in the same environment.ResultsWhen exposed to fish kairomones, the two genotypes exhibited phenotypic variations related to reproduction and growth, with opposite patterns in growth-related phenotypic variation. From both genotypes, a total of 135,611 unigenes were analyzed, of which 194 differentially expressed transcripts (DETs) were shared among the two genotypes under predation stress, which showed consistent, or inconsistent expression patterns in both genotypes. Prominent DETs were related to digestion and reproduction and consistently up-regulated in both genotypes, thus associated with changes in life-history traits. Among the inconsistent DETs, transcripts encode vinculin (VINC) and protein obstructor-E (OBST-E), which are associated with growth; these may explain the differences in life-history traits between the two genotypes. In addition, genotype-specific DETs could explain the variation in growth-related life-history traits between genotypes, and could be associated with the increased body length of genotype KE1.ConclusionsThe current study allows for a better understanding of the adaptation mechanisms related to reproduction and growth of two Korean D. galeata genotypes induced by predation stress. However, further research is necessary to better understand the specific mechanisms by which the uncovered DETs are related with the observed phenotypic variation in each genotype. In the future, we aim to unravel the precise adaptive mechanisms underlying predator-induced responses.

Comparison of age and growth of grass and silver carp above and below Changzhou Dam in the Pearl River, China

The life cycles of potamodromous fishes are generally interrupted by the presence of a dam, and populations often display different life history traits between upstream and downstream. This study compared the age and growth rates of grass carp and silver carp above and below Changzhou Dam in the Pearl River. Standard length (SL) composition and back-calculated SL at ages one and two years were greater for grass carp upstream than for downstream individuals; and the length–weight relationship differed between upstream and downstream populations, while the sex ratio, age structure and growth were not significantly different. For silver carp, only SL compositions differed between upstream and downstream populations; sex ratio, age structure, SL-at-age and growth rates were similar. Mean SL-at-age and growth rates of both species were lower at high latitudes than at middle and low latitudes, and populations in the Yangtze River had greater mean SL-at-ages and faster growth relative to silver carp at low latitudes. There were no differences in mean SL or growth among populations at middle and low latitudes. For grass carp, age and growth varied with small-scale ecological processes and regions or latitude, while for silver carp, such variations were proportionate to latitude and the large-scale geographical range. This study provides not only guidelines for fisheries management and conservation of exploited potamodromous fishes, but also insights into the relationship between life history trait variation and adaptive capacity.

Environmental microbes promote phenotypic plasticity in reproduction and sleep behaviour.

The microbiome has been hypothesized as a driving force of phenotypic variation in host organisms that is capable of extending metabolic processes, altering development and in some cases, conferring novel functions that are critical for survival. Only a few studies have directly shown a causal role for the environmental microbiome in altering host phenotypic features. To assess the extent to which environmental microbes induce variation in host life-history traits and behaviour, we inoculated axenic Drosophila melanogaster with microbes isolated from drosophilid populations collected from two different field sites and generated two populations with distinct bacterial and fungal profiles. We show that microbes isolated from environmental sites with modest abiotic differences induce large variation in host reproduction, fatty acid levels, stress tolerance and sleep behaviour. Importantly, clearing microbes from each experimental population removed the phenotypic differences. The results support the causal role of environmental microbes as drivers of host phenotypic plasticity and potentially, rapid adaptation and evolution.

Spatiotemporal modelling of Greenland halibut maturation across the Northwest Atlantic

AbstractModelling life history trait variation at appropriate spatial and temporal scales is crucial for understanding population dynamics and developing effective fisheries management strategies. However, most efforts to model life history traits ignore spatial correlations and make a priori assumptions about the spatial structuring of populations, potentially clouding the ability to recognize true spatial structure. Here we develop spatiotemporal maturation models for Greenland halibut (Reinhardtius hippoglossoides) in the Northwest Atlantic, a species with large-scale movement patterns that can lead to uncertainty regarding effective stock boundaries. Our analysis using data from three Fisheries and Oceans Canada survey regions, Baffin Bay and Davis Strait in the eastern Canadian Arctic, Newfoundland and Labrador (NL), and the northern Gulf of St. Lawrence (GSL), is the first at such a large spatial scale. We also extend the traditional binary maturity status to a multinomial one that accounts for seasonal changes in maturation. Results show a decreasing temporal trend in size at maturity across the entire area. Spatial results regarding size at maturity provide new insight linking Greenland halibut south of Newfoundland (Northwest Atlantic Fisheries Organization Subdivision 3Ps) to the GSL stock rather than the NL stock. Results also highlight parts of the Davis Strait area, where size at maturity is smaller than in waters both north and south. Multinomial model results identify areas in GSL and Davis Strait that may be important for reproductive development in the summer and fall. Our analyses also reveal constraints on size at maturity that correspond with the well-known positive association between fish length and bottom depth. Broad-scale analyses of high resolution spatial patterns in life history traits, such as those performed here for Greenland halibut maturation, may identify recurrent patterns of association with environmental or habitat characteristics that might not otherwise be evident on a stock- or survey-specific basis.

Ectotherm heat tolerance and the microbiome: current understanding, future directions and potential applications.

Climate change and increasing global temperatures are a leading threat to ectothermic animals worldwide. Ectotherm persistence under climate change will depend on a combination of host and environmental factors; recently it has become clear that host-associated microbial communities contribute significantly to the response of ectotherms to environmental warming. However, several unanswered questions about these relationships remain before accurate predictions can be made regarding the microbiome's influence on host ecology and evolution under climate warming. In this Commentary, we provide a brief background of what is currently known about the influence of the microbiome on heat tolerance in both invertebrate and vertebrate ectothermic animals, and the mechanisms behind these effects. We then outline what we feel are important priorities for future work in the field, and how these goals could be accomplished. We specifically highlight a need for more diversity in study systems, especially through increasing representation of vertebrate hosts and hosts across a variety of life-history traits and habitats, as well as a greater understanding of how these relationships manifest in field settings. Lastly, we discuss the implications of microbiome-mediated heat tolerance for animal conservation under climate change and the possibility of 'bioaugmentation' approaches to bolster host heat tolerance in vulnerable populations.

Effects of population density and environmental conditions on life‐history prevalence in a migratory fish

Individual variation in life-history traits can have important implications for the ability of populations to respond to environmental variability and change. In migratory animals, flexibility in the timing of life-history events, such as juvenile emigration from natal areas, can influence the effects of population density and environmental conditions on habitat use and population dynamics. We evaluated the functional relationships between population density and environmental covariates and the abundance of juveniles expressing different life-history pathways in a migratory fish, Chinook salmon (Oncorhynchus tshawytscha), in the Wenatchee River basin in Washington State, USA. We found that the abundance of younger emigrants from natal streams was best described by an accelerating or near-linear function of spawners, whereas the abundance of older emigrants was best described by a decelerating function of spawners. This supports the hypothesis that emigration timing varies in response to density in natal areas, with younger-emigrating life-history pathways comprising a larger proportion of emigrants when densities of conspecifics are high. We also observed positive relationships between winter stream discharge and abundance of younger emigrants, supporting the hypothesis that habitat conditions can also influence the prevalence of different life-history pathways. Our results suggest that early emigration, and a resultant increase in the use of downstream rearing habitats, may increase at higher population densities and with greater winter precipitation. Winter precipitation is projected to increase in this system due to climate warming. Characterizing relationships between life-history prevalence and environmental conditions may improve our understanding of species habitat requirements and is a first step in understanding the dynamics of species with diverse life-history strategies. As environmental conditions change-due to climate change, management, or other factors-resultant life-history changes are likely to have important demographic implications that will be challenging to predict when life-history diversity is not accounted for in population models.

Northern Europe's suitability for offshore European flat oyster (Ostrea edulis) habitat restoration: A mechanistic niche modelling approach

Abstract After centuries of overexploitation, European flat oyster (Ostrea edulis) habitats are increasingly being protected and large‐scale oyster habitat restoration projects have been initiated in the North Sea, the English Channel, the Irish Sea and the north‐eastern Atlantic. Understanding the habitat requirements of flat oysters is key in the selection process of restoration sites. In this study, a theoretical niche for all life stages of the flat oyster is determined using a dynamic energy budget model forced with temperature, chlorophyll a and salinity in combination with sediment composition. The suitability of Northern Europe's marine environment for flat oysters is evaluated by applying the proposed niche model on a spatial scale and evaluating spatio‐temporal variability in life history traits and metabolic characteristics, such as fitness, reproductive output, settlement success and growth. Results show that habitat suitability is limited by low maximum summer temperature and low food availability at higher latitudes and in areas under strong influence of the Atlantic Ocean. Restoration efforts in Ireland and Scotland should be confined to protected and shallow coastal environments. Suitability in the southern North Sea is patchy and mainly depends on seabed substrate. The nearshore areas of the English Channel are highly suitable. The georeferenced dataset shared in this study will be useful for restoration practitioners.