Integrating Mycorrhizas Into Global Scale Models: A Journey Toward Relevance in the Earth's Climate System

Abstract

Associations between plants and mycorrhizal fungi are ubiquitous in nature and are among the most important trophic interactions affecting ecosystem services and global change. Despite their evolutionary history and current ecological importance, mycorrhizal dynamics have rarely been included in the process-based ecosystem models commonly used to predict vegetation responses to, and mediation of, climate change. Here we provide a framework for incorporating mycorrhizal dynamics into global models, building on well-developed theories of optimal allocation and stoichiometrically-explicit plant-microbe interactions. First we discuss the strengths of existing model frameworks used at the ecosystem scale that can inform global model development. Then we identify mycorrhizal functions that are critical to model at the global scale and highlight how using mycorrhizal fungi as trait integrators may be an important first step in integrating mycorrhizae into global models. We conclude by describing the unique challenges that modeling mycorrhizae at global scales presents.