Ectomycorrhizal fungal diversity predicted to substantially decline due to climate changes in North American Pinaceae forests

Abstract

Aim Ectomycorrhizal fungi (ECMF) are partners in a globally distributed tree symbiosis implicated in most major ecosystem functions. However, resilience of ECMF to future climates is uncertain. We forecast these changes over the extent of North American Pinaceae forests. Location About 68 sites from North American Pinaceae forests ranging from Florida to Ontario in the east and southern California to Alaska in the west. Taxon Ectomycorrhizal fungi (Asco‐ and Basidiomycetes). Methods We characterized ECMF communities at each site using molecular methods and modelled climatic drivers of diversity and community composition with general additive, generalized dissimilarity models and Threshold Indicator Taxa ANalysis (TITAN). Next, we projected our models across the extent of North American Pinaceae forests and forecast ECMF responses to climate changes in these forests over the next 50 years. Results We predict median declines in ECMF species richness as high as 26% in Pinaceae forests throughout a climate zone comprising more than 3.5 million square kilometres of North America (an area twice that of Alaska state). Mitigation of greenhouse gas emissions can reduce these declines, but not prevent them. The existence of multiple diversity optima along climate gradients suggest regionally divergent trajectories for North American ECMF, which is corroborated by corresponding ECMF community thresholds identified in TITAN models. Warming of forests along the boreal–temperate ecotone results in projected ECMF species loss and declines in the relative abundance of long‐distance foraging ECMF species, whereas warming of eastern temperate forests has the opposite effect. Main Conclusions Our results reveal potentially unavoidable ECMF species‐losses over the next 50 years, which is likely to have profound (if yet unclear) effects on ECMF‐associated biogeochemical cycles.

Fungal community turnover along steep environmental gradients from geothermal soils in Yellowstone National Park

“…Specifically, we found the psychrophilic basidiomycete yeast Guehomyces pulullans [57] and a few cold adapted Ascomycete yeasts identified in Vu, Groenewald, Szöke, Cardinali, Eberhardt, Stielow, de Vries, Verkleij, Crous, Boekhout and Robert [58], including Naganishia adeliensis and Udenomyces megalosporus (= U. pyricola in Vu et al 2016). We also found the psychrophiles Elasticomyces elasticus and Mrakia sp., which had been detected in previous soil surveys in both West Yellowstone and Hyalite near Cooke City, Montana [59]. Additionally, our Tausonia pamirica OTU matched 100% to the sequence of the type specimen (Genbank # NR_154490), a known psychrotolerant yeast from Antarctica [60].…”

Stronger Environmental Adaption of Abundant than Rare Microbes in Wetland Soils from the Qinghai-Tibet Plateau

“…Our results emphasized that both abundant bacterial and fungal sub-communities had higher niche breadths, which re ected their adaptations to broader ranges of environmental gradients. Environmental threshold analysis based on TITAN has been reported in some biodiversity-related studies [17,30,55]. For instance, ectomycorrhizal fungal diversity in North American…”

“…Pinaceae forests determines large effects on ectomycorrhizal fungi-associated biogeochemical cycles [55]. The results of environmental breadths of microbes based on environmental threshold analysis are attractive, but are also controversially discussed regarding implications to the real eld situation.…”

Response of soil fungal ecological guilds to global changes

“…While relative abundance of plant fungal pathogens will probably increase in most regions of the world in the near future because of the increasing global temperature (Delgado-Baquerizo et al, 2020a), Steidinger et al (2020), based on model predictions, forecast a substantial decline in ectomycorrhizal fungal diversity in North American coniferous forests. Even mitigation of greenhouse gas emissions during the 21 st century would probably not stop the decline in ectomycorrhizal fungal diversity (Steidinger et al, 2020). Similarly, a recent meta-study focused on soil mycobiome data across the world, identified that in general ectomycorrhizal fungi tend to have narrower climatic niches compared to free living saprotrophs or fungal plant pathogens (V etrovsk y et al, 2019).…”

“…While relative abundance of plant fungal pathogens will probably increase in most regions of the world in the near future because of the increasing global temperature (Delgado‐Baquerizo et al ., 2020a), Steidinger et al . (2020), based on model predictions, forecast a substantial decline in ectomycorrhizal fungal diversity in North American coniferous forests. Even mitigation of greenhouse gas emissions during the 21 st century would probably not stop the decline in ectomycorrhizal fungal diversity (Steidinger et al ., 2020).…”