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1.	Albertsen, Elena, et al. (författare) Using ecological context to interpret spatiotemporal variation in natural selection 2021 Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 75:2, s. 294-309 Tidskriftsartikel (refereegranskat)abstract Spatiotemporal variation in natural selection is expected, but difficult to estimate. Pollinator-mediated selection on floral traits provides a good system for understanding and linking variation in selection to differences in ecological context. We studied pollinator-mediated selection in five populations of Dalechampia scandens (Euphorbiaceae) in Costa Rica and Mexico. Using a nonlinear path-analytical approach, we assessed several functional components of selection, and linked variation in pollinator-mediated selection across time and space to variation in pollinator assemblages. After correcting for estimation error, we detected moderate variation in net selection on two out of four blossom traits. Both the opportunity for selection and the mean strength of selection decreased with increasing reliability of cross-pollination. Selection for pollinator attraction was consistently positive and stronger on advertisement than reward traits. Selection on traits affecting pollen transfer from the pollinator to the stigmas was strong only when cross-pollination was unreliable and there was a mismatch between pollinator and blossom size. These results illustrate how consideration of trait function and ecological context can facilitate both the detection and the causal understanding of spatiotemporal variation in natural selection.
2.	Antão, Laura H., et al. (författare) Climate change reshuffles northern species within their niches 2022 Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 12:6, s. 587-592 Tidskriftsartikel (refereegranskat)abstract Climate change is a pervasive threat to biodiversity. While range shifts are a known consequence of climate warming contributing to regional community change, less is known about how species’ positions shift within their climatic niches. Furthermore, whether the relative importance of different climatic variables prompting such shifts varies with changing climate remains unclear. Here we analysed four decades of data for 1,478 species of birds, mammals, butterflies, moths, plants and phytoplankton along a 1,200 km high latitudinal gradient. The relative importance of climatic drivers varied non-uniformly with progressing climate change. While species turnover among decades was limited, the relative position of species within their climatic niche shifted substantially. A greater proportion of species responded to climatic change at higher latitudes, where changes were stronger. These diverging climate imprints restructure a full biome, making it difficult to generalize biodiversity responses and raising concerns about ecosystem integrity in the face of accelerating climate change.
3.	Holstad, Agnes, et al. (författare) Evolvability predicts macroevolution under fluctuating selection 2024 Ingår i: Science (New York, N.Y.). - 1095-9203. ; 384:6696, s. 688-693 Tidskriftsartikel (refereegranskat)abstract Heritable variation is a prerequisite for evolutionary change, but the relevance of genetic constraints on macroevolutionary timescales is debated. By using two datasets on fossil and contemporary taxa, we show that evolutionary divergence among populations, and to a lesser extent among species, increases with microevolutionary evolvability. We evaluate and reject several hypotheses to explain this relationship and propose that an effect of evolvability on population and species divergence can be explained by the influence of genetic constraints on the ability of populations to track rapid, stationary environmental fluctuations.
4.	Lembrechts, Jonas J., et al. (författare) Global maps of soil temperature 2022 Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:9, s. 3110-3144 Tidskriftsartikel (refereegranskat)abstract Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean=3.0±2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6±2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7±2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.
5.	Opedal, Øystein H., et al. (författare) Evolvability and trait function predict phenotypic divergence of plant populations 2023 Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 120:1 Tidskriftsartikel (refereegranskat)abstract Understanding the causes and limits of population divergence in phenotypic traits is a fundamental aim of evolutionary biology, with the potential to yield predictions of adaptation to environmental change. Reciprocal transplant experiments and the evaluation of optimality models suggest that local adaptation is common but not universal, and some studies suggest that trait divergence is highly constrained by genetic variances and covariances of complex phenotypes. We analyze a large database of population divergence in plants and evaluate whether evolutionary divergence scales positively with standing genetic variation within populations (evolvability), as expected if genetic constraints are evolutionarily important. We further evaluate differences in divergence and evolvability- divergence relationships between reproductive and vegetative traits and between selfing, mixed-mating, and outcrossing species, as these factors are expected to influence both patterns of selection and evolutionary potentials. Evolutionary divergence scaled positively with evolvability. Furthermore, trait divergence was greater for vegetative traits than for floral (reproductive) traits, but largely independent of the mating system. Jointly, these factors explained -40% of the variance in evolutionary divergence. The consistency of the evolvability-divergence relationships across diverse species suggests substantial predictability of trait divergence. The results are also consistent with genetic constraints playing a role in evolutionary divergence.
6.	Pélabon, Christophe, et al. (författare) Is There More to Within-plant Variation in Seed Size than Developmental Noise? 2021 Ingår i: Evolutionary Biology. - : Springer Science and Business Media LLC. - 0071-3260 .- 1934-2845. ; 48:3, s. 366-377 Tidskriftsartikel (refereegranskat)abstract Within-plant variation in seed size may merely reflect developmental instability, or it may be adaptive in facilitating diversifying bet-hedging, that is, production of phenotypically diverse offspring when future environments are unpredictable. To test the latter hypothesis, we analyzed patterns of variation in seed size in 11 populations of the perennial vine Dalechampia scandens grown in a common greenhouse environment. We tested whether population differences in the mean and variation of seed size covaried with environmental predictability at two different timescales. We also tested whether within-plant variation in seed size was correlated with independent measures of floral developmental instability and increased under stressful conditions. Populations differed genetically in the amount of seed-size variation occurring among plants, among infructescences within plants, and among seeds within infructescences. Within-individual variation was not detectably correlated with measures of developmental instability and did not increase under stress, but it increased weakly with short-term environmental unpredictability of precipitation at the source-population site. These results support the hypothesis that greater variation in seed size is adaptive when environmental predictability is low.
7.	Bi, Cheng, et al. (författare) Experimental grazer exclusion increases pollination reliability and influences pollinator-mediated plant-plant interactions in tibetan alpine meadows Ingår i: Alpine Botany. - 1664-2201. Tidskriftsartikel (refereegranskat)abstract 1. Co-flowering plant species often interact through shared pollinators, with effects ranging from positive (facilitation) to negative (competition). It remains unclear how this variation relates to variation in floral density, floral trait distinctiveness, and local environmental conditions. We studied the effect of grazer exclusion, a proposed local management strategy, on pollinator-mediated plant-plant interactions in heavily degraded alpine meadows of the Qinghai-Tibet Plateau. 2. We studied the effect of experimental grazer exclusion on plant reproduction and pollinator-mediated reproductive interactions quantified through pollen transfer networks. We also explored potential mechanisms of pollinator-mediated interspecific pollen transfer and its effect on plant reproductive fitness, including local floral abundance and floral trait distinctiveness among co-flowering species. 3. Grazer exclusion led to greater pollen deposition onto stigmas. The overall quantitative effects of pollinator-mediated interspecific interactions on the receptor species were mainly positive (facilitative) or neutral (with no detectable effect). The frequency of positive relative to negative quantitative effects for pairwise donor-receptor pairs tended to increase after grazer exclusion. Plants with floral traits similar to those of local ‘hub species’ appeared to benefit from pollinator-mediated interactions. 4. Our results suggest an overall positive effect of excluding grazers during the plant growing season on plant reproduction. Facilitative species interactions predominate in harsh environments such as the alpine, and the benefits of pollinator-mediated interactions among plants seemed to exceed the cost of conspecific pollen loss associated with pollinator sharing. This suggest that species invasions into alpine plant communities, an expected consequence of climate change, may not necessarily have negative effects on the reproduction of resident plant species.
8.	Clo, Josselin, et al. (författare) Genetics of quantitative traits with dominance under stabilizing and directional selection in partially selfing species 2021 Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 75:8, s. 1920-1935 Tidskriftsartikel (refereegranskat)abstract Recurrent self-fertilization is thought to lead to reduced adaptive potential by decreasing the genetic diversity of populations, thus leading selfing lineages down an evolutionary “blind alley.” Although well supported theoretically, empirical support for reduced adaptability in selfing species is limited. One limitation of classical theoretical models is that they assume pure additivity of the fitness-related traits that are under stabilizing selection, despite ample evidence that quantitative traits are subject to dominance. Here, we relax this assumption and explore the effect of dominance on a fitness-related trait under stabilizing selection for populations that differ in selfing rates. By decomposing the genetic variance into additional components specific to inbred populations, we show that dominance components can explain a substantial part of the genetic variance of inbred populations. We also show that ignoring these components leads to an upward bias in the predicted response to selection. Finally, we show that when considering the effect of dominance, the short-term evolutionary potential of populations remains comparable across the entire gradient in outcrossing rates, and genetic associations can even make selfing populations more evolvable on the longer term, reconciling theoretical, and empirical results.
9.	Deflem, Io S., et al. (författare) Predicting fish community responses to environmental policy targets 2021 Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 30:5, s. 1457-1478 Tidskriftsartikel (refereegranskat)abstract The European Union adopted the Water Framework Directive (WFD) in the year 2000 to tackle the rapid degradation of freshwater systems. However, biological, hydromorphological, and physico-chemical water quality targets are currently not met, and identifying successful policy implementation and management actions is of key importance. We built a joint species distribution model for riverine fish in Flanders (Belgium) to better understand the response of fish communities to current environmental policy goals. Environmental covariates included physico-chemical variables and hydromorphological quality indices, while waterway distances accounted for spatial effects. We detected strong effects of physico-chemistry on fish species’ distributions. Evaluation of fish community responses to simulated policy scenarios revealed that targeting a ‘good’ status, following the WFD, increases average species richness with a fraction of species (0.13–0.69 change in accumulated occurrence probabilities). Targeting a ‘very good’ status, however, predicted an increase of 0.17–1.38 in average species richness. These simulations indicated that riverbed quality, nitrogen, and conductivity levels should be the focal point of policy. However, the weak response of species to a ‘good’ quality together with the complexity of nutrient-associated problems, suggest a challenging future for river restoration in Flanders.
10.	Hagenberg, Liyenne Wu Chen, et al. (författare) Vegetation change on mountaintops in northern Sweden: Stable vascular-plant but reordering of lichen and bryophyte communities 2022 Ingår i: Ecological Research. - : Wiley. - 0912-3814 .- 1440-1703. ; 37:6, s. 722-737 Tidskriftsartikel (refereegranskat)abstract Alpine ecosystems harbor remarkably diverse and distinct plant communities that are characteristically limited to harsh, and cold climatic conditions. As a result of thermal limitation to species occurrence, mountainous ecosystems are considered to be particularly sensitive to climate change. Our understanding of the impact of climate change is mainly based on vascular plants however, whereas cryptogams (i.e., lichens and bryophytes) are generally neglected or simply considered as one functional group. Here we aimed to improve our understanding of the drivers underlying temporal changes in vegetation of alpine ecosystems. To this end, we repeatedly surveyed the vegetation on four mountain summits along an elevational gradient in northern Sweden spanning a 19-year period. Our results show that the vascular plant communities remained relatively stable throughout the study period, despite fluctuations in terms of ground cover and species richness of shrubs and graminoids. In contrast, both lichens and bryophytes substantially decreased in cover and diversity, leading to alterations in community composition that were unrelated to vascular plant cover. Thermophilization of the vascular plant community was found only on the two intermediate summits. Our findings are only partially consistent with (long-term) climate-change impacts, and we argue that local non-climatic drivers such as herbivory might offset vegetation responses to warming. Hence, we underline the importance of considering local non-climatic drivers when evaluating temporal vegetation change in biologically complex systems.
11.	Hederström, Veronica, et al. (författare) Pollinator-mediated effects of landscape-scale land use on grassland plant community composition and ecosystem functioning – seven hypotheses Ingår i: Biological Reviews. - 1464-7931. Tidskriftsartikel (refereegranskat)abstract Environmental change is disrupting mutualisms between organisms worldwide. Reported declines in insect populations and changes in pollinator community compositions in response to land use and other environmental drivers have put the spotlight on the need to conserve pollinators. While this is often motivated by their role in supporting crop yields, the role of pollinators for reproduction and resulting taxonomic and functional assembly in wild plant communities has received less attention. Recent findings suggest that observed and experimental gradients in pollinator availability can affect plant community composition, but we know little about when such shifts are to be expected, or the impact they have on ecosystem functioning. Correlations between plant traits related to pollination and plant traits related to other important ecosystem functions, such as productivity, nitrogen uptake or palatability to herbivores, lead us to expect non-random shifts in ecosystem functioning in response to changes in pollinator communities. At the same time, ecological and evolutionary processes may counteract these effects of pollinator declines, limiting changes in plant community composition, and in ecosystem functioning. Despite calls to investigate community- and ecosystem-level impacts of reduced pollination, the study of pollinator effects on plants has largely been confined to impacts on plant individuals or single-species populations. With this review we aim to break new ground by bringing together aspects of landscape ecology, ecological and evolutionary plant–insect interactions, and biodiversity–ecosystem functioning research, to generate new ideas and hypotheses about the ecosystem-level consequences of pollinator declines in response to land-use change, using grasslands as a focal system. Based on an integrated set of seven hypotheses, we call for more research investigating the putative pollinator-mediated links between landscape-scale land use and ecosystem functioning. In particular, future research should use combinations of experimental and observational approaches to assess the effects of changes in pollinator communities over multiple years and across species on plant communities and on trait distributions both within and among species.
12.	Hou, Meng, et al. (författare) Sexually concordant selection on floral traits despite greater opportunity for selection through male fitness 2024 Ingår i: New Phytologist. - 0028-646X. ; 241:2, s. 926-936 Tidskriftsartikel (refereegranskat)abstract Pollinators are important drivers of floral trait evolution, yet plant populations are not always perfectly adapted to their pollinators. Such apparent maladaptation may result from conflicting selection through male and female sexual functions in hermaphrodites. We studied sex-specific mating patterns and phenotypic selection on floral traits in Aconitum gymnandrum. After genotyping 1786 offspring, we partitioned individual fitness into sex-specific selfed and outcrossed components and estimated phenotypic selection acting through each. Relative fitness increased with increasing mate number, and more so for male function. This led to greater opportunity for selection through outcrossed male fitness, though patterns of phenotypic selection on floral traits tended to be similar, and with better support for selection through female rather than male fitness components. We detected directional selection through one or more fitness component for larger flower number, larger flowers, and more negative nectar gradients within inflorescences. Our results are consistent with Bateman's principles for sex-specific mating patterns and illustrate that, despite the expected difference in opportunity for selection, patterns of variation in selection across traits can be rather similar for the male and female sexual functions. These results shed new light on the effect of sexual selection on the evolution of floral traits.
13.	Mattila, Anniina L.K., et al. (författare) Evolutionary and ecological processes influencing chemical defense variation in an aposematic and mimetic Heliconius butterfly 2021 Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 9 Tidskriftsartikel (refereegranskat)abstract Chemical defences against predators underlie the evolution of aposematic coloration and mimicry, which are classic examples of adaptive evolution. Surprisingly little is known about the roles of ecological and evolutionary processes maintaining defence variation, and how they may feedback to shape the evolutionary dynamics of species. Cyanogenic Heliconius butterflies exhibit diverse warning color patterns and mimicry, thus providing a useful framework for investigating these questions. We studied intraspecific variation in de novo biosynthesized cyanogenic toxicity and its potential ecological and evolutionary sources in wild populations of Heliconius erato along environmental gradients, in common-garden broods and with feeding treatments. Our results demonstrate substantial intraspecific variation, including detectable variation among broods reared in a common garden. The latter estimate suggests considerable evolutionary potential in this trait, although predicting the response to selection is likely complicated due to the observed skewed distribution of toxicity values and the signatures of maternal contributions to the inheritance of toxicity. Larval diet contributed little to toxicity variation. Furthermore, toxicity profiles were similar along steep rainfall and altitudinal gradients, providing little evidence for these factors explaining variation in biosynthesized toxicity in natural populations. In contrast, there were striking differences in the chemical profiles of H. erato from geographically distant populations, implying potential local adaptation in the acquisition mechanisms and levels of defensive compounds. The results highlight the extensive variation and potential for adaptive evolution in defense traits for aposematic and mimetic species, which may contribute to the high diversity often found in these systems.
14.	Nilsson, Kalle J., et al. (författare) Colonization of a Novel Host Plant Reduces Phenotypic Variation Ingår i: Evolutionary Biology. - 0071-3260. Tidskriftsartikel (refereegranskat)abstract Understanding the evolution of evolvability—the evolutionary potential of populations—is key to predicting adaptation to novel environments. Despite growing evidence that evolvability structures adaptation, it remains unclear how adaptation to novel environments in turn influences evolvability. Here we address the interplay between adaptation and evolvability in the peacock fly Tephritis conura, which recently underwent an adaptive change in ovipositor length following a host shift. We compared the evolvability of morphological traits, including ovipositor length, between the ancestral and the derived host race. We found that mean evolvability was reduced in females of the derived host race compared to the ancestral host race. However, patterns of multivariate evolvability (considering trait covariances) were very similar in both host races, and populations of the derived host race had diverged from the ancestral host race in directions of greater-than-average evolvability. Exploration of phenotypic integration patterns further revealed relatively high levels of independent variation in ovipositor length compared to other measured traits, allowing some degree of independent divergence. Our findings suggest that adaptation to novel environments can reduce mean evolvability without major changes in patterns of variational constraints, and that trait autonomy helps facilitate divergence of functionally important traits.
15.	Opedal, Øystein H., et al. (författare) A database and synthesis of euglossine bee assemblages collected at fragrance baits 2020 Ingår i: Apidologie. - : Springer Science and Business Media LLC. - 0044-8435 .- 1297-9678. ; 51:4, s. 519-530 Tidskriftsartikel (refereegranskat)abstract Euglossine bees are an ecologically important group, which due to their diverse resource needs act as pollinators of many neotropical plants. Male euglossines collect fragrant compounds used in mating displays from diverse sources, including the flowers of orchids and other plants. This aspect of euglossine biology has proven exceptionally useful for studies of euglossine bee populations, because male bees can be readily attracted to fragrance baits deployed in natural habitats. We synthesise the data accumulated over the 50 years since the introduction of euglossine bee baiting inventories and make these data openly available in the EUGCOMM database. By fitting hierarchical joint species distribution models to presence-absence and abundance data, we reveal that the assemblages of bees attracted depend on the baits used in interaction with species-specific fragrance preferences and that bee assemblages are most diverse at sites in landscapes characterised by partial but not complete forest cover. We suggest that these results reflect the diverse resource needs of euglossine bees and are consistent with the hypothesis that male euglossines establish home ranges incorporating multiple habitat types. These results may have important consequences for the design of nature reserves in the tropics, if these iconic pollinators are to be conserved for the future.
16.	Opedal, Øystein H. (författare) A functional view of flower-pollinator trait matching. A commentary on 'Mismatching explained : constricted corolla tubes in Roscoea elevate the nectar' 2023 Ingår i: Annals of Botany. - 0305-7364. ; 132:6 Tidskriftsartikel (refereegranskat)
17.	Opedal, Øystein H. (författare) A FUNCTIONAL VIEW REVEALS SUBSTANTIAL PREDICTABILITY OF POLLINATOR-MEDIATED SELECTION 2021 Ingår i: Journal of Pollination Ecology. - : International Commission for Plant Pollinator Relations. - 1920-7603. ; 29, s. 273-288 Forskningsöversikt (refereegranskat)abstract A predictive understanding of adaptation to changing environments hinges on a mechanistic understanding of the extent and causes of variation in natural selection. Estimating variation in selection is difficult due to the complex relationships between phenotypic traits and fitness, and the uncertainty associated with individual selection estimates. Plant-pollinator interactions provide ideal systems for understanding variation in selection and its predictability, because both the selective agents (pollinators) and the process linking phenotypes to fitness (pollination) are generally known. Through examples from the pollination literature, I discuss how explicit consideration of the functional mechanisms underlying trait-performance relationships can clarify the relationship between traits and fitness, and how variation in the ecological context that generates selection can help disentangle biologically important variation in selection from sampling variation. I then evaluate the predictability of variation in pollinator-mediated selection through a survey, reanalysis, and synthesis of results from the literature. The synthesis demonstrates that pollinator-mediated selection often varies substantially among trait functional groups, as well as in time and space. Covariance between patterns of selection and ecological variables provides additional support for the biological importance of observed selection, but the detection of such covariance depends on careful choice of relevant predictor variables as well as consideration of quantitative measurements and their meaning, an aspect often neglected in selection studies.
18.	Opedal, Øystein H., et al. (författare) Evolvability and constraint in the evolution of three-dimensional flower morphology 2022 Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 109:11, s. 1906-1917 Tidskriftsartikel (refereegranskat)abstract Premise: Flower phenotypes evolve to attract pollinators and to ensure efficient pollen transfer to and from the bodies of pollinators or, in self-compatible bisexual flowers, between anthers and stigmas. If functionally interacting traits are genetically correlated, response to selection may be subject to genetic constraints. Genetic constraints can be assessed by quantifying standing genetic variation in (multivariate) phenotypic traits and by asking how much the available variation is reduced under specific assumptions about phenotypic selection on functionally interacting and genetically correlated traits. Methods: We evaluated multivariate evolvability and potential genetic constraints underlying the evolution of the three-dimensional structure of Dalechampia blossoms. First, we used data from a greenhouse crossing design to estimate the G matrix for traits representing the relative positions of male and female sexual organs (anthers and stigmas) and used the G matrix to ask how genetic variation is distributed in multivariate space. To assess the evolutionary importance of genetic constraints, we related standing genetic variation across phenotypic space to evolutionary divergence of population and species in the same phenotypic directions. Results: Evolvabilities varied substantially across phenotype space, suggesting that certain traits or trait combinations may be subject to strong genetic constraint. Traits involved functionally in flower-pollinator fit and autonomous selfing exhibited considerable independent evolutionary potential, but population and species divergence tended to occur in phenotypic directions associated with greater-than-average evolvability. Conclusions: These results are consistent with the hypothesis that genetic constraints can hamper joint trait evolution towards optimum flower-pollinator fit and optimum self-pollination rates.
19.	Opedal, Øystein H., et al. (författare) Herbivores reduce seedling recruitment in alpine plant communities 2021 Ingår i: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 39:2 Tidskriftsartikel (refereegranskat)abstract Through changes in climate and other environmental factors, alpine tundra ecosystems are subject to increased cover of erect shrubs, reduced predictability of rodent dynamics and changes in wild and domesticated herbivore densities. To predict the dynamics of these ecosystems, we need to understand how these simultaneous changes affect alpine vegetation. In the long term, vegetation dynamics may depend critically on seedling recruitment. To study drivers of alpine plant seedling recruitment, we set up a field experiment where we manipulated the opportunity for plant–plant interactions through vegetation removal and introduction of willow transplants, the occurrence of herbivory through caging of plots, and then sowed 14 species into the plots. We replicated the experiment in three common alpine vegetation types (heath, meadow and Salix shrubland) and recorded seedling emergence and survival over five years. Strong effects of vegetation removal and substantial differences in recruitment among dominant vegetation types suggested important effects of local vegetation on the recruitment success of vascular-plant seedlings. Similarly, herbivore exclusion had strong positive effects on recruitment success. This effect arose primarily via reduced seedling mortality in plots from which herbivores had been experimentally excluded and became noticeably stronger over time. In contrast, we detected no consistent effects of experimental willow shrub introduction on seedling recruitment. These results demonstrate that large and small herbivores can affect alpine plant seedling recruitment negatively by trampling and feeding on seedlings. Importantly, the effects became stronger over time, suggesting that effects of herbivory on seedling recruitment accumulates over time and may relate to recruitment phases beyond initial seedling emergence.
20.	Opedal, Øystein H., et al. (författare) Host-plant availability drives the spatiotemporal dynamics of interacting metapopulations across a fragmented landscape 2020 Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 101:12 Tidskriftsartikel (refereegranskat)abstract The dynamics of ecological communities depend partly on species interactions within and among trophic levels. Experimental work has demonstrated the impact of species interactions on the species involved, but it remains unclear whether these effects can also be detected in long-term time series across heterogeneous landscapes. We analyzed a 19-year time series of patch occupancy by the Glanville fritillary butterfly Melitaea cinxia, its specialist parasitoid wasp Cotesia melitaearum, and the specialist fungal pathogen Podosphaera plantaginis infecting Plantago lanceolata, a host plant of the Glanville fritillary. These species share a network of more than 4,000 habitat patches in the Åland islands, providing a metacommunity data set of unique spatial and temporal resolution. To assess the influence of interactions among the butterfly, parasitoid, and mildew on metacommunity dynamics, we modeled local colonization and extinction rates of each species while including or excluding the presence of potentially interacting species in the previous year as predictors. The metapopulation dynamics of all focal species varied both along a gradient in host plant abundance, and spatially as indicated by strong effects of local connectivity. Colonization and to a lesser extent extinction rates depended also on the presence of interacting species within patches. However, the directions of most effects differed from expectations based on previous experimental and modeling work, and the inferred influence of species interactions on observed metacommunity dynamics was limited. These results suggest that although local interactions among the butterfly, parasitoid, and mildew occur, their roles in metacommunity spatiotemporal dynamics are relatively weak. Instead, all species respond to variation in plant abundance, which may in turn fluctuate in response to variation in climate, land use, or other environmental factors.
21.	Opedal, Øystein H., et al. (författare) Measuring, comparing and interpreting phenotypic selection on floral scent 2022 Ingår i: Journal of evolutionary biology. - : Wiley. - 1010-061X .- 1420-9101. ; 35:11, s. 1432-1441 Tidskriftsartikel (refereegranskat)abstract Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with previous analyses in terms of identifying populations and scent compounds subject to stronger selection but also allowed us to evaluate and compare the strength of selection on scent across studies. Doing so revealed that selection on floral scent was highly variable, and overall about as common and as strong as selection on other phenotypic traits involved in pollinator attraction or pollen transfer. These results are consistent with an important role of floral scent in pollinator attraction. Our approach should be useful for further studies of plant–animal communication and for studies of selection on other high-dimensional phenotypes. In particular, our approach will be useful for studies of pollinator-mediated selection on complex scent blends comprising many volatiles, and when no prior information on the physiological responses of pollinators to scent compounds is available.
22.	Opedal, Øystein H., et al. (författare) Pollen as the link between floral phenotype and fitness 2023 Ingår i: American Journal of Botany. - 0002-9122. ; 110:6 Tidskriftsartikel (refereegranskat)abstract Pollen plays a key role in plant reproductive biology. Despite the long history of research on pollen and pollination, recent advances in pollen-tracking methods and statistical approaches to linking plant phenotype, pollination performance, and reproductive fitness yield a steady flow of exciting new insights. In this introduction to the Special Issue “Pollen as the Link Between Phenotype and Fitness,” we start by describing a general conceptual model linking functional classes of floral phenotypic traits to pollination-related performance metrics and reproductive fitness. We use this model as a framework for synthesizing the relevant literature, highlighting the studies included in the Special Issue, and identifying gaps in our understanding and opportunities for further development of the field. The papers that follow in this Special Issue provide new insights into the relationships between pollen production, presentation, flower morphology, and pollination performance (e.g., pollen deposition onto stigmas), the role of pollinators in pollen transfer, and the consequences of heterospecific pollen deposition. Several of the studies demonstrate exciting experimental and analytical approaches that should pave the way for continued work addressing the intriguing role of pollen in linking plant phenotypes to reproductive fitness.
23.	Pontarp, Mikael, et al. (författare) Evolutionary plant–pollinator responses to anthropogenic land-use change : impacts on ecosystem services Ingår i: Biological Reviews. - 1464-7931. Tidskriftsartikel (refereegranskat)abstract Agricultural intensification at field and landscape scales, including increased use of agrochemicals and loss of semi-natural habitats, is a major driver of insect declines and other community changes. Efforts to understand and mitigate these effects have traditionally focused on ecological responses. At the same time, adaptations to pesticide use and habitat fragmentation in both insects and flowering plants show the potential for rapid evolution. Yet we lack an understanding of how such evolutionary responses may propagate within and between trophic levels with ensuing consequences for conservation of species and ecological functions in agroecosystems. Here, we review the literature on the consequences of agricultural intensification on plant and animal evolutionary responses and interactions. We present a novel conceptualization of evolutionary change induced by agricultural intensification at field and landscape scales and emphasize direct and indirect effects of rapid evolution on ecosystem services. We exemplify by focusing on economically and ecologically important interactions between plants and pollinators. We showcase available eco-evolutionary theory and plant–pollinator modelling that can improve predictions of how agricultural intensification affects interaction networks, and highlight available genetic and trait-focused methodological approaches. Specifically, we focus on how spatial genetic structure affects the probability of propagated responses, and how the structure of interaction networks modulates effects of evolutionary change in individual species. Thereby, we highlight how combined trait-based eco-evolutionary modelling, functionally explicit quantitative genetics, and genomic analyses may shed light on conditions where evolutionary responses impact important ecosystem services.
24.	Qiu, Yizhi, et al. (författare) Proximity to oilseed rape fields affects plant pollination and pollinator-mediated selection on a co-flowering plant on the Tibetan Plateau 2023 Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:4, s. 814-823 Tidskriftsartikel (refereegranskat)abstract The ecological effects of mass-flowering crops on pollinator abundance and species richness of neighbouring habitats are well established, yet the potential evolutionary consequences remain unclear. We studied effects of proximity to a mass-flowering crop on the pollination of local co-flowering plants and on patterns of natural selection on a pollination-generalised plant on the Tibetan Plateau. We recorded pollinator visitation rates and community composition at different distances (near vs. far) to oilseed rape (Brassica napus) fields in two habitat types and quantified pollinator-mediated selection on attractive traits of Trollius ranunculoides. The proximity to oilseed rape increased pollinator visitation in neighbouring alpine meadows and changed pollinator composition in neighbouring shrub meadows. Trollius ranunculoides in the alpine meadow near oilseed rape received three times more pollinator visits (mainly bees) and consequently had a 16.5% increase in seed set but also received slightly more heterospecific pollen per stigma. In contrast, pollinator visitation to T. ranunculoides in the shrub meadow near oilseed rape was three times lower (mainly flies), leading to a 10.7% lower seed despite no effect on pollen deposition. The proximity to the oilseed rape field intensified pollinator-mediated selection on flower size and weakened selection on flower height of T. ranunculoides in the alpine meadow but did not affect phenotypic selection on either trait in the shrub meadow. Our study highlights context-dependent variation in plant–pollinator interactions close to mass-flowering oilseed rape, suggesting potential effects on the evolution of flower traits of native plants through altered pollinator-mediated selection. However, context dependence may make these effects difficult to predict.
25.	Ray, Courtenay A., et al. (författare) Linking microenvironment modification to species interactions and demography in an alpine plant community 2023 Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 2023:3 Tidskriftsartikel (refereegranskat)abstract Individual plants can modify the microenvironment within their spatial neighborhood. However, the consequences of microenvironment modification for demography and species interactions remain unclear at the community scale. In a study of co-occurring alpine plants, we 1) determined the extent of species-specific microclimate modification by comparing temperature and soil moisture between vegetated and non-vegetated microsites for several focal species. We 2) determined how vital rates (survival, growth, fecundity) of all species varied in response to aboveground and belowground vegetative overlap with inter- and intraspecific neighbors as proxies for microenvironment modification. For 1), surface temperatures were buffered (lower maximums and higher minimums) and soil moisture was higher below the canopies of most species compared to non-vegetated areas. For 2), vegetative overlap predicted most vital rates, although the effect varied depending on whether aboveground or belowground overlap was considered. Vital rate response to microenvironment-modification proxies (vegetative overlap) was also frequently context dependent with respect to plant size and macroclimate. Microenvironment modification and spatial overlapping of individuals are key drivers of demography and species interactions in this alpine community.
26.	Rodríguez-Otero, Cristina, et al. (författare) Analysis of trait–performance–fitness relationships reveals pollinator-mediated selection on orchid pollination traits 2023 Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 110:6 Tidskriftsartikel (refereegranskat)abstract Premise: The role of pollinators in evolutionary floral divergence has spurred substantial effort into measuring pollinator-mediated phenotypic selection and its variation in space and time. For such estimates, the fitness consequences of pollination processes must be separated from other factors affecting fitness. Methods: We built a fitness function linking phenotypic traits of food-deceptive orchids to female reproductive success by including pollinator visitation and pollen deposition as intermediate performance components and used the fitness function to estimate the strength of pollinator-mediated selection through female reproductive success. We also quantified male performance as pollinarium removal and assessed similarity in trait effects on male and female performance. Results: The proportion of plants visited at least once by an effective pollinator was moderate to high, ranging from 53.7% to 85.1%. Tall, many-flowered plants were often more likely to be visited and pollinated. Given effective pollination, pollen deposition onto stigmas tended to be more likely for taller plants. Pollen deposition further depended on traits affecting the physical fit of pollinators to flowers (flower size, spur length), though the exact relationships varied in time and space. Using the fitness function to assess pollinator-mediated selection through female reproductive success acting on multiple traits, we found that selection varied detectably among taxa after accounting for sampling uncertainty. Across taxa, selection on most traits was stronger on average and more variable when pollination was less reliable. Conclusions: These results support pollination-related trait–performance–fitness relationships and thus pollinator-mediated selection on traits functionally involved in the pollination process.
27.	Ten Brink, Hanna, et al. (författare) Seasonality and competition select for variable germination behavior in perennials 2023 Ingår i: Evolution; international journal of organic evolution. - 1558-5646. ; 77:8, s. 1791-1805 Tidskriftsartikel (refereegranskat)abstract The occurrence of within-population variation in germination behavior and associated traits such as seed size has long fascinated evolutionary ecologists. In annuals, unpredictable environments are known to select for bet-hedging strategies causing variation in dormancy duration and germination strategies. Variation in germination timing and associated traits is also commonly observed in perennials and often tracks gradients of environmental predictability. Although bet-hedging is thought to occur less frequently in long-lived organisms, these observations suggest a role of bet-hedging strategies in perennials occupying unpredictable environments. We use complementary analytical and evolutionary simulation models of within-individual variation in germination behavior in seasonal environments to show how bet-hedging interacts with fluctuating selection, life-history traits, and competitive asymmetries among germination strategies. We reveal substantial scope for bet-hedging to produce variation in germination behavior in long-lived plants, when "false starts" to the growing season results in either competitive advantages or increased mortality risk for alternative germination strategies. Additionally, we find that lowering adult survival may, in contrast to classic bet-hedging theory, result in less spreading of germination by decreasing density-dependent competition. These models extend insights from bet-hedging theory to perennials and explore how competitive communities may be affected by ongoing changes in climate and seasonality patterns.
28.	Wells, Harry B.M., et al. (författare) Experimental evidence that effects of megaherbivores on mesoherbivore space use are influenced by species' traits 2021 Ingår i: Journal of Animal Ecology. - : Wiley. - 0021-8790 .- 1365-2656. ; 90:11, s. 2510-2522 Tidskriftsartikel (refereegranskat)abstract The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2–1,000 kg), and (b) the extent to which the responses of each mesoherbivore species was predictable based on their traits (diet and shoulder height) and phylogenetic relatedness. Megaherbivores increased the predicted occurrence and use intensity of zebras but reduced the occurrence and use intensity of several other mesoherbivore species. The negative effect of megaherbivores on mesoherbivore occurrence was stronger for shorter species, regardless of diet or relatedness. Megaherbivores substantially reduced the expected total use intensity (i.e. cumulative dung density of all species) of mesoherbivores, but only minimally reduced the expected species richness (i.e. cumulative predicted occurrence probabilities of all species) of mesoherbivores (by <1 species). Simulated extirpation of megaherbivores altered use intensity by mesoherbivores, which should be considered during (re)introductions of megaherbivores or their ecological proxies. Species' traits (in this case shoulder height) may be more reliable predictors of mesoherbivores' responses to megaherbivores than phylogenetic relatedness, and may be useful for predicting responses of data-limited species.

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