Nina Sletvold

• Uppsala University

Understanding how historical versus contemporary processes shape population genetic structure and diversity is important to design effective management actions for threatened species. We genotyped 1834 SNPs in 1120 individuals from 110 Scandinavian populations of the declining orchid Gymnadenia conopsea, in three different habitat types, to examine...

Mimicry implies that an organism gains fitness by resembling a model species, and one example is rewardless plants that attract pollinators by resembling co-flowering species that provide rewards. While trait matching between mimic and model has been characterised in many cases of putative floral mimicry, few have demonstrated that resemblance is a...

Population size is a main indicator of conservation potential, thought to predict both current and long‐term population viability. However, few studies have directly examined the links between the size and the genetic and demographic properties of populations, using metrics that integrate effects across the whole life cycle. In this study, we combi...

Many Lepidoptera species are declining to the point that active measures such as reinforcements and reintroductions are necessary to maintain viable populations. To maximise success of such efforts, we need to understand the factors influencing habitat preferences for oviposition. In a Swedish island population of the red‐listed chequered blue butt...

Assisted gene flow can restore genetic diversity when genetic drift has driven deleterious alleles to high frequencies in small, isolated populations. Previous crosses among 20 populations of Gymnadenia conopsea documented the strongest heterosis and the weakest inbreeding depression in sparse and small populations, consistent with fixation of mild...

Premise Density‐dependent pollinator visitation can lead to density‐dependent mating patterns and within‐population genetic structure. In Gymnadenia conopsea , individuals in low‐density patches receive more self pollen than individuals in high‐density patches, suggesting higher relatedness at low density. Ongoing fragmentation is also expected to...

Whole‐plant senescence, defined as a decrease in individual fitness as an organism grows older, has often been assumed to not occur in plants; however, it has now been detected in a range of plant taxa. Still, reported senescence patterns vary substantially, and it remains unknown how consistent patterns are within phylogenetic groups and how they...

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 r...

Pollinator sharing between close relatives can be costly, which can promote pollination niche partitioning and floral divergence. This should be reflected by a higher species divergence in sympatry than in allopatry. We tested this hypothesis in two orchid congeners with overlapping distributions and flowering times. We characterized floral traits...

Effective population size should be positively related to census size and density, and it is expected to influence the strength of genetic drift, inbreeding and response to selection, and thus the distribution of the genetic load across populations. We examined whether census population size and density predict the strength of inbreeding depression...

Closely related species often differ in traits that influence reproductive success, suggesting that divergent selection on such traits contribute to the maintenance of species boundaries. Gymnadenia conopsea ss. and Gymnadenia densiflora are two closely related, perennial orchid species that differ in (a) floral traits important for pollination, in...

Seed production is critical to the persistence of most flowering plant populations, but may be strongly pollen limited. To what extent long-lived plants can compensate pollen limitation by increasing future reproduction is poorly understood. We tested for compensation in two Dactylorhiza species that differ in reproductive investment by experimenta...

Aim Intraspecific trait variation (ITV) within natural plant communities can be large, influencing local ecological processes and dynamics. Here, we shed light on how ITV in vegetative and floral traits responds to large‐scale abiotic and biotic gradients (i.e., climate and species richness). Specifically, we tested whether associations of ITV with...

Understanding the mechanisms of adaptive population differentiation requires that both the functional and adaptive significance of divergent traits are characterized in contrasting environments. Here, we (a) determined the effects of floral spur length on pollen removal and receipt using plants with artificial spurs representing the species‐wide va...

Floral scent is a crucial trait for pollinator attraction. Yet only a handful of studies have estimated selection on scent in natural populations and no study has quantified the relative importance of pollinators and other agents of selection. In the fragrant orchid Gymnadenia conopsea, we used electroantennographic data to identify floral scent co...

Identifying traits and agents of selection involved in local adaptation is important for understanding population divergence. In southern Sweden, the moth‐pollinated orchid Platanthera bifolia occurs as a woodland and a grassland ecotype that differ in dominating pollinators. The woodland ecotype is taller (expected to influence pollinator attracti...

Long-term demographic data are needed for detailed viability analyses of populations threatened by climate change, but the infeasibility of obtaining such data makes it urgent to assess whether demographic responses to climatic variation can be generalized across populations and species. We used 32 years of demographic data on four species of close...

Vegetative dormancy, that is the temporary absence of aboveground growth for ≥ 1 year, is paradoxical, because plants cannot photosynthesise or flower during dormant periods. We test ecological and evolutionary hypotheses for its widespread persistence. We show that dormancy has evolved numerous times. Most species displaying dormancy exhibit life‐...

Background and aims: Floral scent is considered an integral component of pollination syndromes, and its composition and timing of emission are thus expected to match the main pollinator type and time of activity. While floral scent differences among plant species with different pollination systems can be striking, studies on intraspecific variatio...

In animal‐pollinated plants, the opportunity for selection and the strength of pollinator‐mediated selection are expected to increase with the degree of pollen limitation. However, whether differences in pollen limitation can explain variation in pollinator‐mediated and net selection among animal‐pollinated species is poorly understood. In the pres...

The dominant evolutionary theory of actuarial senescence—an increase in death rate with advancing age—is based on the concept of a germ cell line that is separated fromthe somatic cells early in life. However, such a separation is not clear in all organisms. This has been suggested to explain the paucity of evidence for actuarial senescence in plan...

The link between biotic interaction intensity and strength of selection is of fundamental interest for understanding biotically driven diversification and predicting the consequences of environmental change. The strength of selection resulting from biotic interactions is determined by the strength of the interaction and by the covariance between fi...

Female reproductive success is predicted to be simultaneously limited by the availability of pollen and resources. Selection on floral traits results from both factors, but their relative importance and interaction is poorly understood. We increased nutrient and pollen availability of the orchid Dactylorhiza lapponica in a factorial experiment to q...

Contrasting flower color patterns that putatively attract or direct pollinators towards a reward are common among angiosperms. In the deceptive orchid Anacamptis morio, the lower petal, which makes up most of the floral display, has a light central patch with dark markings. Within populations, there is pronounced variation in petal brightness, patc...

Figure S1: Plots of the Kaplan-Meier estimators of the survivorship curves. Figure S2: Mortality and survivorship over age since first reproduction, and parameter values, of the second-best fitting mortality model (logistic including reproductive investment and no Makeham term). Figure S3: Mortality, survivorship and parameter values of the best-fi...

Figure S1: Plots of the Kaplan-Meier estimators of the survivorship curves. Figure S2: Mortality and survivorship over age since first reproduction, and parameter values, of the second-best fitting mortality model (logistic including reproductive investment and no Makeham term). Figure S3: Mortality, survivorship and parameter values of the best-fi...

Hybridization between populations or species can have pronounced fitness consequences. Yet little is known about how hybridization affects gene regulation. Three main models have been put forward to explain gene expression patterns in hybrids: additive, dominance or parental effects. Here we use high throughput RNA-sequencing to examine the extent...

Spatial variation in plant–pollinator interactions may cause variation in pollinator-mediated selection on floral traits, but to establish this link conclusively experimental studies are needed.We quantified pollinator-mediated selection on flowering phenology and morphology in four populations of the fragrant orchid Gymnadenia conopsea, and compar...

A trade‐off between current reproduction and future performance is a key component of life‐history theory, but the shape of this trade‐off for any specific fitness component remains elusive. We induced three to five levels of reproductive effort ( RE ) by manipulating fruit set of a long‐lived orchid in two populations that differed in the length o...

Knowledge of which genes and pathways are affected by inbreeding may help understanding the genetic basis of inbreeding depression, the potential for purging (selection against deleterious recessive alleles) and the transition from outcrossing to selfing. Arabidopsis lyrata is a predominantly self-incompatible perennial plant, closely related to th...

Costs of reproduction are expected to vary with environmental conditions thus influencing selection on life-history traits. Yet, the effects of habitat conditions and climate on trade-offs among fitness components remain poorly understood. For 2-5 years, we quantified costs of experimentally increased reproduction in two populations (coastal long-s...

Mutualists and antagonists are known to respond to similar floral cues, and may thus cause opposing selection on floral traits. However, we lack a quantitative understanding of their independent and interactive effects. In a population of the orchid Gymnadenia conopsea, we manipulated the intensity of pollination and herbivory in a factorial design...

Spatial variation in pollinator-mediated selection (Δβpoll ) is a major driver of floral diversification, but we lack a quantitative understanding of its link to pollen limitation and net selection on floral traits. For 2-5 years, we quantified Δβpoll on floral traits in two populations each of two orchid species differing in pollen limitation. In...

Inbreeding depression is a key factor influencing mating system evolution in plants, but current understanding of its relationship with selfing rate is limited by a sampling bias with few estimates for self-incompatible species. We quantified inbreeding depression (δ) over two growing seasons in two populations of the self-incompatible perennial he...

Clarifying the relationship between environmental context and the adaptive significance of floral traits is fundamental for an understanding of spatial and temporal variation in pollinator-mediated selection. We manipulated vegetation height and pollination regime of the orchid Dactylorhiza lapponica in a factorial design to test whether pollinator...

Climate change is expected to influence the viability of populations both directly and indirectly, via species interactions. The effects of large-scale climate change are also likely to interact with local habitat conditions. Management actions designed to preserve threatened species therefore need to adapt both to the prevailing climate and local...

Conservation of species threatened by habitat fragmentation is a major global challenge, and determining the genetic and demographic processes associated with isolation and reductions in population size will be critical for an increasing number of species. We conducted controlled crosses and field germination experiments to quantify the effects of...

Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal a...

Pollinators may mediate selection on traits affecting pollinator attraction and effectiveness, and while nonadditive effects of traits influencing the two components of pollination success are expected when seed production is pollen limited, they have been little studied. In a factorial design, we manipulated one putative attraction trait (number o...

A cost of reproduction in terms of reduced future performance underlies all life-history models, yet costs have been difficult to detect in short-term experiments with long-lived plants. The likelihood of detecting costs should depend on the range of variation in reproductive effort that can be induced, and also on the shape of the cost function ac...

The ability to cope with water limitation influences plant distributions, and several plant traits have been interpreted as adaptations to drought stress. In Scandinavia, the perennial herb Arabidopsis lyrata occurs in open habitats that differ widely in climate and water availability in summer, suggesting differential selection on drought-related...

Theory predicts that trade-offs between resistance to herbivory and other traits positively affecting fitness can maintain genetic variation in resistance within plant populations. In the perennial herb Arabidopsis lyrata, trichome production is a resistance trait that exhibits both qualitative and quantitative variation. Using a paternal half-sib...

Spatial variation in plant-pollinator interactions may cause variation in pollinator-mediated selection on floral traits, but to establish this link conclusively experimental studies are needed. We quantified pollinator-mediated selection on flowering phenology and morphology in four populations of the fragrant orchid Gymnadenia conopsea, and compa...

• Nonrewarding animal-pollinated plants commonly experience severe pollen limitation, which should result in strong selection on traits affecting the success of pollination. However, the importance of pollinators as selective agents on floral traits in deceptive species has not been quantified experimentally. • Here, we quantified pollinator-mediat...

Many orchids are currently red-listed due to changes in land use, and their future persistence will depend on management. Traditional land use like mowing is believed to favour orchids through increased survival and reproduction of established individuals, but the lack of data connecting their complex life cycle presently limits our ability to eval...

In this year celebrating the bicentenary of Darwin's birth, and the sesquicentennial of the publication of 'On the Origin of Species', our paper aims to review Darwin's history as a plant scientist, and his contribution to current research in plant evolutionary ecology. We start out with a biographical sketch, and continue with an overview of his p...

Insect herbivores search for their host plants in heterogeneous environments, and the efficiency of host location may be influenced by plant architecture and abundance. In this study, we ask how plant and habitat characteristics traditionally thought to attract pollinators are related to attack rates by floral herbivores. Patterns of floral herbivo...

Summary 1. Plant ecologists have long since realized that the persistence of many facultative biennial plants depends upon disturbance. However, we still have a limited knowledge of the population-level effects of disturbance, and the connection between adult and seed bank dynamics. 2. Using data from a 3-year demographic study combined with experi...

Despite recent, strong interest in the modelling of monocarpic perennial flowering strategies, little is known about how variation in demographic rates affects selection on optimal timing of flowering. Temporal variation may yield fluctuating selective pressures, or, if individuals experience time trends, selection for phenotypic plasticity. Here w...

Pollinator visitation patterns in relation to variation in floral display size may be modified both quantitatively and qualitatively by local plant density. In this study four measures of pollinator response by Bombus spp. (plant visitation rate, bout length, proportion of flowers visited, flower visitation rate) were investigated under two or thre...

Summary 1 Density-dependent effects on vital rates may vary in both magnitude and direction at different stages of the life cycle. In monocarpic perennials, however, it is often assumed that recruitment is the stage most affected by density. 2 The spatial pattern of newly emerged individuals of the facultative biennial Digitalis purpurea was record...

Monocarpy in facultative biennials can be favoured by selection when there is a more than proportional increase in fitness with size. The possible contributions of larger reproductive output and higher offspring quality to such an increase were investigated in the facultative biennial plant Digitalis purpurea . Straw mass (rosette leaves and flower...