A lattice-based system for modeling fungal mycelial growth in complex environments

Fungi are one of the most destructive agents to wood and wood-based products, resulting in the decrease of the building service life by breaking down lumber structures. This work presents a discrete lattice-based model to simulate the mycelial growth, which explicitly incorporates tip extension, extension angle, branching and anastomosis. The developed algorithm reduces greatly the geometrical restriction of the lattice to hyphal elongation; thus, it is able to generate realistic mycelial networks with low computational costs. Different growth conditions are reproduced via tropisms which influence the tip dominant direction, such as thigmotropism that enables hyphae to bend around the obstacles in structurally-heterogeneous media. The validation of this model is implemented through an experiment focusing on the morphology and the growth of Postia placenta, a species of brown rot fungus. Some model parameters are directly obtained from the experimental data, while others have to be determined by inverse procedure. This validated model is an efficient tool for predicting the mycelial growth under different conditions over a large spatial scale, thereby allowing upscaling from laboratory to macroscopic scale.