Biology subjects

Klein, E. K.

Publications and source records attributed to Klein, E. K..

3 recordsLinked to original sources

bioRxiv2023

Intertwining of fecundity, sexual and growth selection on spring phenology along an altitudinal gradient of European beech (Fagus sylvatica L.).

BackgroundPlant phenological traits such as the timing of budburst or flowering can evolve on ecological timescales through response to fecundity and viability selection. However, interference with sexual selection may arise from assortative mating. This study aims to investigate how these three components of selection on spring phenology may combine in European beech populations in contrasting environments (high versus low altitude). Methodswe monitored the timing of budburst (TBB) in 339 adult beech trees and estimated their fecundity using spatially explicit mating models. Fecundity selection was infered by regressing fecundities on TBB, while sexual selection was inferred by regressing fecundities on mating opportunities (i.e., TBB mismatch). The correlation between mates for flowering time (i.e., assortative mating) was estimated based on paternity analyses. Morever, TBB and growth were surveyed in 3261 seedlings from 40 families grown planted in a common garden, and viability selection was inferred by regressing growth on TBB. ResultsOverall, directional fecundity selection on female fitness favored trees with earlier TBB. Sexual selection acted only on male fitness through assortative mating favoring trees with mean TBB value (stabilizing selection). In the common garden, early budburst was associated with higher seedling growth. The respective intensities of directional and stabilizing selection varied with the environment: at low altitude, directional selection for earlier phenology was modulated by strong assortative mating and by an interaction effect between TBB an size on female fecundity, whereas at high altitude, directional selection for earlier phenology was reinforced by selection through male fecundity. DiscussionThis study showed that selection through female fecundity and seedlings growth predominantly selected for earlier TBB, while sexual selection on male fitness through assortative mating modulated this trend. This interplay between fecundity and sexual selection calls for an integrative approach to predict the evolution of spring phenology under a changing climate.

evolutionary biology↗

bioRxiv2020

Emerging strains of watermelon mosaic virus in Southeastern France: model-based estimation of the dates and places of introduction

Where and when alien organisms are successfully introduced are central questions to elucidate biotic and abiotic conditions favorable to the introduction, establishment and spread of invasive species. We propose a modelling framework to analyze multiple introductions by several invasive genotypes or genetic variants, in competition with a resident population, when observations provide knowledge on the relative proportions of each variant at some dates and places. This framework is based on a mechanistic-statistical model coupling a reaction-diffusion model with a probabilistic observation model. We apply it to a spatio-temporal dataset reporting the relative proportions of five genetic variants of watermelon mosaic virus (WMV, genus Potyvirus, family Potyviridae) in infections of commercial cucurbit fields. Despite the parsimonious nature of the model, it succeeds in fitting the data well and provides an estimation of the dates and places of successful introduction of each emerging variant as well as a reconstruction of the dynamics of each variant since its introduction.

ecology↗

bioRxiv2019

Drivers of individual oak tree selection by acorn dispersing animals inferred from a genotyped seedling cohort

Seed-dispersing animals can strongly influence plant reproductive success and resulting population structures. Few studies have disentangled different drivers of disperser foraging behavior in natural settings and their actual relevance for plant fitness. Here we adopt a novel approach to investigate the drivers of individual trees dispersal success in a mixed Pedunculate oak-Pyrenean oak (Quercus robur and Q. pyrenaica) forest stand. We genotyped a seedling cohort (n = 825) upon emergence and performed Bayesian parentage analyses to infer the acorn dispersal success of each oak tree in the stand. We then modeled this estimate as a function of six tree characteristics. The absolute number of animal-dispersed seedlings was exclusively predicted by crop size and the proportion of dispersed seedlings by the number of fruiting oaks in the neighborhood. Neither the oak species nor tree height, acorn size or shape played any role. Our findings contrast with results from experimental studies and suggest that effective acorn dispersers, despite being scatter-hoarders, behaved much like avian dispersers of fleshy-fruited species when selecting trees to forage on. Their behavior should favor the dominance of large, prolific trees for the dynamics and genetic composition of naturally regenerating oak stands.

ecology↗