Modeling the Geographic Distribution of Cantharellus formosus Under Climate Change

Abstract

Maximum entropy, presence-only, species distribution modeling of the current and future habitat of Cantharellus formosus across North America is modeled under a range of climate change scenarios. C. formosus is a culturally and economically important ectomycorrhizal Basidiomycetes mushroom species which is highly prized by foragers for its gourmet flavor. It is symbiotic with Pseudotsuga menziesii (Douglas Fir) and widespread along the US west coast, particularly in heavily forested areas of Washington and Oregon, west of the Cascades. C. formosus has been observed as far south as Berkeley, California, and as far north as southern Alaska, as well as in limited areas of the northern Rockies, near the Canada - Idaho border. Using 663 research-grade, crowed-sourced presence observations obtained from the Global Biodiversity Information Facility and 23 ecological variables, the ecological-niche and species distribution of C. formosus was modeled using a maximum entropy, machine learning algorithm. Further, the future distribution of C. formosus was forecast using a range of climate projections, out to the year 2100. Projections indicate that highly suitable habitat is likely to decline, by 8% to 94%, particularly in California where multiple projections show a complete loss of highly suitable habitat. Conversely, suitable and somewhat suitable habitat may increase by upwards of 100%, as the projected habitat migrates to the north. Importantly, due to the ecology and symbiotic nature of C. formosus, while loss of habitat may occur relatively quickly under changing climatic conditions, establishment and/or expansion into new habitat is likely to be slower by comparison.