Short Rotations in Forest Plantations Accelerate Virulence Evolution in Root-Rot Pathogenic Fungi

Authored by Jean-Paul Soularue, Cecile Robin, Marie-Laure Desprez-Loustau, Cyril Dutech

Date Published: 2017

DOI: 10.3390/f8060205

Sponsors: No sponsors listed

Platforms: Python

Model Documentation: Other Narrative Flow charts

Model Code URLs: Model code not found

Abstract

As disease outbreaks in forest plantations are causing concern worldwide, a clear understanding of the influence of silvicultural practices on the development of epidemics is still lacking. Importantly, silvicultural practices are likely to simultaneously affect epidemiological and evolutionary dynamics of pathogen populations. We propose a genetically explicit and individual-based model of virulence evolution in a root-rot pathogenic fungus spreading across forest landscapes, taking the Armillaria ostoyae-Pinus pinaster pathosystem as reference. We used the model to study the effects of rotation length on the evolution of virulence and the propagation of the fungus within a forest landscape composed of even-aged stands regularly altered by clear-cutting and thinning operations. The life cycle of the fungus modeled combines asexual and sexual reproduction modes, and also includes parasitic and saprotrophic phases. Moreover, the tree susceptibility to the pathogen is primarily determined by the age of the stand. Our simulations indicated that the shortest rotation length accelerated both the evolution of virulence and the development of the epidemics, whatever the genetic variability in the initial fungal population and the asexuality rate of the fungal species.

Tags

Management Dispersal Population-structure Colonization Forestry Pine forest Genetic-structure Adaptive evolution Host-parasite interactions Tree fungal pathogen Root-rot disease Heterobasidion annosum Ganoderma boninense Evolutionary epidemiology Quantitative host-pathogen interaction Asexuality Clonality Saprotrophism Armillaria-ostoyae Ecology perspective