Abstract It is increasingly recognized that evolution may occur in ecological time. not clear, however, how fast – or phenotypic change more generally be comparison with the associated ecology, whether systems dynamics have relatively rates of change. We developed a new dataset on standardized population size and traits for wide range species taxonomic groups. show phenotypes are no than 2/3, average about 1/4, concurrent size. There was relationship between across systems. also found...

Thermal stratification is common in lentic freshwater systems, and has extensive effects on ecosystem function the interactions between aquatic organisms their surroundings. Although thermal regimes temperate systems are well-characterized, small arctic subarctic lakes ponds can have irregular regimes, conditions leading to mixing less predictable. Nevertheless, they be important habitats for northern fish species, ecological processes, including dissolved oxygen dynamics, may determine...

Abstract Measuring microalgae density in soft‐sediment benthos has challenges for even the most sophisticated methods. If goal is to assess photosynthetic potential of epipelon, then should be sampled only at surface depth light penetration. Furthermore, may show spatial and temporal variability that can captured by using many point samples nondestructive sampling. Here, we use simple near‐infrared (NIR) imagery soft underwater sediments infer their capacity. In lab studies, NIR gives...

Pulsed fluxes of organisms across ecosystem boundaries can exert top-down and bottom-up effects in recipient food webs, through both direct on the subsidized trophic levels indirect other components system. While previous theoretical empirical studies demonstrate influence allochthonous subsidies processes, understanding how these forces act conjunction is still limited, particularly when an resource simultaneously subsidize multiple levels. Using Lake Mývatn region Iceland as example system...

Abstract Light is a primary driver of lake ecosystem metabolism, and the dependence production on light often quantified as photosynthesis‐irradiance or “P‐I” curve. The parameters P‐I curve (e.g., maximum when in excess) can change through time due to variety biological factors changes biomass community composition), which themselves are subject external drivers herbivory nutrient availability). However, relative contribution variation overall metabolism largely unknown. I developed...

Abstract Species abundance is typically determined by the abiotic environment, but extent to which such effects occur through mediation of biotic interactions, including mutualisms, unknown. We explored how light environment (open meadow vs. shaded understory) mediates and ant tending aphid Aphis helianthi feeding on herb Ligusticum porteri . Yearly surveys consistently found aphids be more than 17‐fold abundant open plants understory plants. Manipulations demonstrated that this pattern was...

Plants have evolved both physical and chemical defenses to make the nutrients of attacked organs difficult access or more toxic resist animal consumption or/and pathogen attack. Although it is intuitive that a tradeoff could exist between because finite defense resources, many studies failed detect this tradeoff. We hypothesized in individual was mediated by total resource allocation those organs. In study, we tested whether (i.e. fiber content, which has proved be good indicator investment...

Abstract Understanding how nutrient limitation affects algal biomass and production is a long‐standing interest in aquatic ecology. Nutrients can influence these whole‐community characteristics through several mechanisms, including shifting community composition. Therefore, incorporating the joint responses of biomass, taxonomic composition, communities, relationships among them, important for understanding effects enrichment. In shallow subarctic Lake Mývatn, Iceland, benthic algae compose...

Abstract Nonbiting midges (family Chironomidae) are found throughout the world in a diverse array of aquatic and terrestrial habitats, can often tolerate harsh conditions such as hypoxia or desiccation, have consistently compact genomes. Yet we know little about shared molecular basis for these attributes how they evolved across family. Here, address questions by first creating high-quality, annotated reference assemblies Tanytarsus gracilentus (subfamily Chironominae, tribe Tanytarsini)...

The relative contributions of benthic and pelagic primary production affect ecosystem function, but studies documenting natural variation in the partitioning (i.e., autotrophic structure) are uncommon. This study examines structure shallow Lake Mývatn over 7 summers (2012–2018). We used routine measurements gross (GPP), chlorophyll a concentrations, to estimate maximum productivity (Pmax) across summers. With these parameters corresponding incident light water clarity data, we estimated situ...

Abstract Adaptive genetic divergence occurs when selection imposed by the environment causes genomic component of phenotype to differentiate. However, signatures natural are usually identified without information on which trait is responding selective agent(s). Here, we integrate whole‐genome sequencing with phenomics and measures putative agents assess extent adaptive in threespine stickleback occupying highly heterogeneous lake Mývatn, NE Iceland. We find negligible genome wide divergence,...

Abstract Ecosystem engineers can have diverse and conflicting effects on their ecosystems, the balance between these depend physical environment. This context dependence means that environmental variation produce large differences in engineer through space time. Here, we explore how local variability conditions lead to spatiotemporal effect of tube‐building midges benthic ecosystem metabolism a shallow subarctic lake. Using field experiments, found midge engineering increases both gross...

Abstract Animals show among‐individual variation in behaviors, including migration which are often repeatable across time periods and contexts, commonly termed “personality.” These behaviors can be correlated, forming a behavioral syndrome. In this study, we assessed the repeatability correlation of different traits, i.e., boldness, exploration, sociality, link to feeding patterns Atlantic cod juveniles. To do so, collected repeated measurements within two short‐term (3 days) long‐term (2...

Identifying microevolutionary change in the wild requires linking trait to shifts allele fre-quencies, but existing approaches poorly account for different modes of selection that act simulta-neously on correlated traits. Using an integrative phenome-genome time-series dataset collected threespine stickleback (Gasterosteus aculeatus), we identified how selec-tion (directional, balancing, and episodic) drive over time. Specifically, show dietary traits our population changed linearly by...

A central goal in evolutionary biology is to understand how different processes cause trait change wild populations. However, quantifying the requires linking shifts allele frequencies at causal loci. Nevertheless, datasets that allow for such tests are extremely rare and existing theoretical approaches poorly account dynamics likely occur ecological settings. Using a decade-long integrative phenome-to-genome time-series dataset on threespine stickleback ( Gasterosteus aculeatus ), we...

Quantifying temporal variation in demographic rates is a central goal of population ecology. In this study, we analyzed multidecadal age-structured time series Arctic char (Salvelinus alpinus) abundance Lake Mývatn, Iceland, to infer the time-varying response reduced harvest wake fishery’s collapse. Our analysis shows that while survival probability adults increased following alleviation harvesting pressure, per capita recruitment consistently declined over most study period, until final...

1. Intraspecific competition for food may affect the development, survival, and fecundity of organisms. However, environmental variation in abiotic conditions can influence resource quality and/or quantity, thereby modifying strength intraspecific competition. 2. This study focuses on among Tanytarsus gracilentus (Chironomidae: Diptera) larvae. In Lake Mývatn, Iceland, T. undergoes large population fluctuations, evidence suggests that these fluctuations are governed by consumer‐resource...

Many consumers depend on the contemporaneous growth of their food resources. For example, Tanytarsus gracilentus midges feed algae, and because midge generation time is much longer than that individual benefit not just from standing stock but also algae during lifespans. This implies an intermediate consumption rate maximizes somatic growth: low rates constrain they do fully utilize available food, whereas high suppress algal biomass consequently limit future availability. An experiment...

Abstract While climate warming is widely predicted to reduce body size of ectotherms, evidence for this trend mixed. Body depends not only on temperature but also other factors, such as food quality and intraspecific competition. Because trends or long‐term environmental factors may affect population sources, attributing in average requires the separation potentially confounding effects. We evaluated midge Tanytarsus gracilentus potential drivers (water temperature, size, quality) between...

AbstractUncovering the demographic basis of population fluctuations is a central goal biology. This particularly challenging for spatially structured populations, which require disentangling synchrony in rates from coupling via movement between locations. In this study, we fit stage-structured metapopulation model to 29-year time series threespine stickleback abundance heterogeneous and productive Lake Mývatn, Iceland. The lake comprises two basins (North South) connected by channel through...

Abstract Historically, estimates of pelagic primary production in lake ecosystems were made by measuring the uptake carbon‐14 ( 14 C)‐labeled inorganic carbon samples incubated under laboratory or situ conditions. However, incubation approaches are increasingly being replaced methods that analyze diel changes high‐frequency data such as free‐water dissolved oxygen (O 2 ). While there is a rich literature on comparison for estimating using incubations (e.g., C and O bottle experiments), well...

Ecosystem engineers have large impacts on the communities in which they live, and these may feed back to populations of themselves. In this study, we assessed effect ecosystem engineering density-dependent feedbacks for midges Lake Mývatn, Iceland. The midge larvae reside sediment build silk tubes that provide a substrate algal growth, thereby elevating benthic primary production. Benthic algae are turn food source larvae, setting stage effects Using field mesocosm experiment manipulating...

Population cycles can be caused by consumer-resource interactions. Confirming the role of interactions, however, challenging due to an absence data for resource candidate. For example, interactions between midge larvae and benthic algae likely govern high-amplitude population fluctuations Tanytarsus gracilentus in Lake Mývatn, Iceland, but there are no records resources concurrent with adult counts. Here, we investigate consumer dynamics using carbon stable isotope signatures archived T....