Biology subjects

Vandegehuchte, M. L.

Publications and source records attributed to Vandegehuchte, M. L..

7 recordsLinked to original sources

bioRxiv2026

Context-dependent selection and genetic facilitation and constraint on rosette diameter and herbivore resistance across european outdoor common gardens under ambient and reduced precipitation in Fragaria vesca

The expression of plant defensive traits against herbivores often incurs costs to other essential functions, such as growth and reproduction. Understanding how selection acts on putatively functional traits that are expected to trade off across space and time is therefore critical for predicting evolutionary responses to ongoing and future environmental change. Here, we used multiple replicated genotypes of woodland strawberry (Fragaria vesca; Rosaceae) grown over two years in three outdoor common gardens in Spain, Belgium, and Sweden. In each garden, genotypes were exposed to both a reduced-precipitation treatment simulating drought and an ambient precipitation treatment. We estimated directional and correlational selection on rosette diameter (a proxy for growth) and herbivore resistance (measured as the inverse of chewing damage) using fruit and stolon production as proxies for sexual and asexual fitness across all environments (i.e., every site x year x treatment combination). We then combined selection gradients with environment-specific genetic (co)variance among genotypes to quantify the expected response to selection ({Delta}z = G{beta}) and to identify covariance-driven constraints or facilitation therein. Selection consistently favored larger rosette diameter for both fitness proxies across nearly all environments, which, in combination with genetic covariances among genotypes, resulted in a general evolutionary response toward increased rosette diameter, with the strongest response at the wettest site (Belgium). In contrast, selection on resistance and the corresponding among-genotype evolutionary responses were strongly context-dependent. Correlational selection on rosette diameter x resistance occurred in only a few environments, primarily under reduced precipitation. Environment-dependent genetic covariances constrained or facilitated selection on both traits only at the site with the highest herbivory (Sweden) under drought conditions. Overall, our results reveal a context-dependent interplay between selection and genetic architecture, underlining the difficulty of predicting evolutionary trajectories under environmental change, and highlighting how spatially and temporally variable conditions may maintain standing genetic variation in plant traits.

evolutionary biology↗

bioRxiv2025

Variation in phenotypic plasticity of metabolic and performance traits along a latitudinal gradient in Woodland Strawberry

Phenotypic plasticity and local adaptation jointly determine plant responses to environmental variation, yet their relative contributions and evolutionary interactions remain poorly understood. We grew fifteen woodland strawberry (Fragaria vesca) genotypes from a European latitudinal gradient in four common gardens for two years, quantifying primary metabolites and biomass, reproduction and herbivore damage-related traits. Considering all measured traits combined, environment explained the largest variance (30%), followed by genotype-by-environment interactions (18%) and genotype effects (9%), indicating substantial heritable plasticity. However, plasticity was not uniform: northern genotypes showed greater plasticity in stress metabolites like succinic acid but more canalized growth traits, whereas southern genotypes maintained constitutively high protective metabolite levels. Latitude explained 4.4% of plasticity profile variation. Phenotypic variation was consistently better explained by long-term temperature than precipitation at the site of origin across all trait groups under study. Our results indicate that plasticity itself is an evolved, trait-specific characteristic shaped by climatic gradients, challenging simple hierarchies of trait lability. Significance StatementWe studied wild strawberries from across Europe and discovered that populations from different regions have evolved distinct adaptive strategies to cope with their local cli-mates. These differences highlight the remarkable diversity of plant solutions to environmental challenges. Understanding these natural adaptations could help us breed strawberries or other plant organisms better suited to future climate conditions.

ecology↗

bioRxiv2020

Belowground plant-plant signaling of root infection by nematodes

Communication between plants mediated by herbivore-induced volatile organic compounds has been extensively studied aboveground. However, the role of root herbivory in belowground plant-plant communication is much less understood. We here investigated whether root herbivores can trigger plant roots to emit warning signals to neighbouring plants that are not yet in direct contact with them. We used a split-root system and infected half of the roots of Agrostis stolonifera plants with root-knot nematodes (Meloidogyne minor) and left the other half uninfected. As a control, we grew plants without nematodes in separate pots. Leachates from each split-root soil compartment and from soils with control plants were applied to separate pots with A. stolonifera plants, of which biomass allocation and morphological traits were measured one month after leachate addition. Plants receiving leachates from the soil with the nematode-free roots of the nematode-infected plants showed a significantly larger total biomass, more root branches, and deeper rooting than plants receiving leachates from the soil with the nematode-infected roots or from soil with control plants. Plants were taller and the root/shoot ratio was higher in plants receiving leachates from soil with the nematode-free roots than in plants receiving leachates from soil with nematode-infected roots. Shoot tiller number was higher in plants receiving leachates from either soil of the nematode-infected plants than in plants receiving control leachates. Our results suggest that an overcompensation response was triggered by systemically induced root-derived compounds from nematode-free roots of a plant locally infected with root-feeding nematodes. Signals from directly attacked roots of the same nematode-infected plant only caused receiver plants to develop more shoot tillers, possibly for future stolon development to grow away from the infected area. This may indicate an anticipatory tolerance response to root feeders that are still distant and an additional generalized escape response to root feeding.

ecology↗

bioRxiv2018

Habitat loss and fragmentation increase realized predator-prey body size ratios

In the absence of predators, habitat fragmentation favors large body sizes in primary consumers with informed movement due to their high gap-crossing ability. However, the body size of primary consumers is not only shaped by such bottom-up effects, but also by top-down effects as predators prefer prey of a certain size. Therefore, higher trophic levels should be taken into consideration when studying the effect of habitat loss and fragmentation on size distributions of herbivores.\n\nWe built a model to study the effect of habitat loss and fragmentation within a simple food web consisting of (i) a basal resource that is consumed by (ii) a herbivore that in turn is consumed by (iii) a predator. Our results highlight that predation may result in local accumulation of the resource via top-down control of the herbivore. As such, the temporal and spatial variation of the resource distribution is increased, selecting for increased herbivore movement. This results in selection of larger herbivores than in the scenario without predator. As predators cause herbivores to be intrinsically much larger than the optimal sizes selected by habitat fragmentation in the absence of predators, habitat fragmentation is no longer a driver of herbivore size. However, there is selection for increased predator size with habitat fragmentation as herbivores become less abundant, favoring gap-crossing ability of the predator. Since herbivore and predator body size respond differently to habitat loss and fragmentation, realized predator-herbivore body size ratios increase along this fragmentation gradient. Our model predicts the dominance of top-down forces in regulating body size selection in food webs and helps to understand how habitat destruction and fragmentation affect overall food web structure.

ecology↗

bioRxiv2018

Habitat choice stabilizes metapopulation dynamics through increased ecological specialisation.

Dispersal is a key trait responsible for the spread of individuals and genes among local populations, thereby generating eco-evolutionary interactions. Especially in heterogeneous metapopulations, a tight coupling between dispersal, population dynamics and the evolution of local adaptation is expected. In this respect, current theory predicts dispersal to counteract ecological specialisation by redistributing locally selected phenotypes (i.e. migration load). However, in nature we observe that some specialists exhibit a strong dispersal capacity.\n\nHabitat choice following informed dispersal decisions, provides a possible mechanism for individuals to match the environment to their phenotype, thereby enabling the persistence of evolved ecological specialisation. How such informed decisions affect the evolution of dispersal and ecological specialisation and how these, in turn, influence metapopulation dynamics is yet to be determined.\n\nBy means of individual-based modelling, we show that informed decisions on both departure and settlement decouples the evolution of dispersal and generalism, favouring highly dispersive specialists. Choice at settlement decouples dispersal from ecological specialisation most effectively. Additionally, habitat choice stabilizes local and metapopulation demography because of the maintenance of ecological specialisation at all levels of dispersal propensity.\n\nWe advocate considering habitat choice in spatially structured ecological models to improve demographic predictions in the face of environmental change.

evolutionary biology↗

bioRxiv2018

Size-dependent movement explains why bigger is better in fragmented landscapes

Body size is a fundamental trait known to allometrically scale with metabolic rate, and therefore a key determinant of individual development, life history and consequently fitness. In spatially structured environments, movement is an equally important driver of fitness. Because movement is tightly coupled with body size, we expect habitat fragmentation to induce a strong selection pressure on size variation across and within species. Changes in body size distributions are then, in turn, expected to alter food web dynamics. However, no consensus has been reached on how spatial isolation and resource growth affect body size distributions.\n\nOur aim was to investigate how these two factors shape the body size distribution of consumers under scenarios of size-dependent and -independent consumer movement by applying a mechanistic, individual-based resource-consumer model. The outcome was then linked to important ecosystem traits such as resource abundance and stability. Finally, we determined those factors that explain most variation in size distributions.\n\nWe demonstrate that decreasing connectivity and resource growth select for communities (or populations) consisting of larger species (or individuals) due to strong selection for the ability to move over longer distances. When including size-dependent movement, moderate levels of connectivity result in increases in local size diversity. Due to this elevated functional diversity, resource uptake is optimized at the metapopulation or metacommunity level. At these intermediate levels of connectivity, size-dependent movement explains most of the observed variation in size distributions. Interestingly, local and spatial stability of consumer biomass are lowest when isolation and resource productivity are high. Finally, we highlight that size-dependent movement is of vital importance for the survival of populations within highly fragmented landscapes. Our results demonstrate that considering size-dependent movement and resource growth is essential to understand patterns of size distributions at the population or community level and the resulting metapopulation or metacommunity dynamics.

ecology↗

bioRxiv2018

Information use during movement regulates how fragmentation and loss of habitat affect body size.

An individual's body size is central to its behavior and physiology, and tightly linked to its dispersal ability. The spatial arrangement of resources and a consumer's capacity to locate them are therefore expected to exert strong selection on consumer body size.\n\nWe investigated the evolutionary impact of both the fragmentation and loss of habitat on consumer body size and its feedback effects on resource distribution, under varying levels of information use during the settlement phase of dispersal. We developed a mechanistic, individual-based, spatially explicit model, including several allometric rules for key consumer traits. Our model reveals that as resources become more fragmented and scarce, informed settlement selects for larger body sizes while random settlement promotes small sizes. Information use may thus be an overlooked explanation for the observed variation in body size responses to habitat fragmentation. Moreover, we find that resources can accumulate and aggregate if information on resource abundance is incomplete. Informed movement results in stable resource-consumer dynamics and controlled resources across space. However, habitat fragmentation and loss destabilize local dynamics and disturb resource suppression by the consumer. Considering information use during movement is thus critical to understand the eco-evolutionary dynamics underlying the functioning and structuring of consumer communities.

ecology↗