MMEE2024

Mathematical Models in Ecology and Evolution

July 15-18, 2024
Vienna, AUSTRIA

"Differences in root architecture increase persistence time in simulated plant communities"

Salinas, Hugo

Plant species differ in morphological traits that play a crucial role in both intra- and interspecific interactions, such as root architecture. While some argue that differences in root architecture can significantly influence species persistence in a community through affecting inter- and intra-specific interactions, others believe their impact is minimal. However, due to the complexities involved in observing and controlling root systems, experimentally testing this presents significant challenges. We used a simulation approach to explore how differences in root architecture affect the persistence of species in a community, compared to communities composed of species without such differences.?The experiments were performed using a functional-structural plant model that simulates the growth of individuals with an explicit 3D root system that forages for water.?We conducted grid-based experiments in which plants competed for water and produced seeds depending on their above-ground biomass, which then germinated and formed the community in the next generation.?Each individual belonged to one of five species. These species represent root architectural adaptations for contrasting (low to high) plant densities and were generated by an evolutionary algorithm that optimized for above-ground biomass. Overall, simulated communities tended to have two species that persisted across generations, corresponding to those evolved under the highest and lowest densities.?Stochastic reproduction rate and seed dispersal caused population sizes to oscillate, which in some cases led to the extinction of a species.? Simulated communities persisted longer (or even indefinitely) if the root architecture of the species in the community were more different.?This is because such differences add a density-dependent effect that allows species to recover from low densities.? Our results suggest that developmental and reproductive stochasticity, and niche differences, in the form of root architecture, can determine the persistence of a species in a community. These patterns align with predictions from neutral and niche theory.

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