Continental‐scale macrofungal assemblage patterns correlate with climate, soil carbon and nitrogen deposition

Abstract

Aim Macroecological scales of species compositional trends are well documented for a variety of plant and animal groups, but remain sparse for fungi, despite their ecological importance in carbon and nutrient cycling. It is, thus, essential to understand the composition of fungal assemblages across broad geographical scales and the underlying drivers. Our overall aim was to describe these patterns for fungi across two nutritional modes (saprotrophic and ectomycorrhizal). Furthermore, we aimed to elucidate the temporal component of fruiting patterns and to relate these to soil carbon and nitrogen deposition. Location Central and Northern Europe. Methods A total of 4.9 million fungal fruit body observations throughout Europe, collected between 1970 and 2010, were analysed to determine the two main environmental and geographical gradients structuring fungal assemblages for two main nutritional modes, saprotrophic and ectomycorrhizal fungi. Results Two main gradients explaining the geography of compositional patterns were identified, for each nutritional mode. Mean annual temperature (and related collinear, seasonal measures) correlated most strongly with the first gradient for both nutritional modes. Soil organic carbon was the highest correlate of the second compositional gradient for ectomycorrhizal fungi, suspected as an indicator of vegetation‐ and pH‐related covariates. In contrast, nitrogen deposition constituted a second gradient for saprotrophic fungi, likely a proxy for anthropogenic pollution. Compositional gradients and environmental conditions correlated similarly when the data were divided into two time intervals of 1970–1990 and 1991–2010. Evidence of compositional temporal change was highest with increasing elevation and latitude. Main conclusions Fungal assemblage patterns demonstrate clear biogeographical patterns that relate the nutritional modes to their main environmental correlates of temperature, soil organic carbon and nitrogen deposition. With respect to global change impacts, the highest rates of compositional change by time suggest targeting higher latitudes and elevations for a better understanding of fungal dynamics. We, finally, suggest further examination of the ranges and dispersal abilities of fungi to better assess responses to global change.

Open‐source data reveal how collections‐based fungal diversity is sensitive to global change

“…Seasonality is likely the reason for the significance of collection day precipitation, as its patterns better captured coastal highs of western Europe (Appendix 6). That a precipitation signal was picked up contrasts with previous research on phenology (Andrew et al, 2018a) and assemblages (Andrew et al, 2018b), and demonstrates the power of dynamic covariates to enhance our understanding of the effect of global change on fungi.…”

“…Collections databases formed through museum specimens and curated citizen science data (inclusive of individual and group “amateur” collections and surveys) are ideal for macroecology research, relating the presence of organisms to global change and, especially, past to present impacts of climate (Lavoie, ; Wen et al., ; Andrew et al., ; Willis et al., ). Patterns and processes governing the biogeographical distributions of organisms in their natural environments can be elucidated across geographical gradients at previously unprecedented scales (Andrew et al., , b). The environmental roles shaping fungal diversity are open for investigation, especially within a backdrop of global change (Fisher et al., ; Pärtel et al., ; Soudzilovskaia et al., ; Titeux et al., ; Mucha et al., ).…”

“…For example, urbanization and forest management each impact biodiversity (Paillet et al., ; Dvořák et al., ), with interactions between land‐use change and climate (Mair et al., ) as well as tree species diversity (Spake et al., ). Likewise, climate affects assemblages of fungi, which consequently impacts phenological patterns (Talbot et al., ; Andrew et al., , b). Potentially cascading effects include those to diversity, dispersal, and composition (Titeux et al., ).…”

Macroecology in the age of Big Data – Where to go from here?

“…For example, a biogeographic assessment of saprotrophic and ectomycorrhizal fungi (Andrew et al, 2018) was based on a Big Data integration effort (Andrew et al, 2017), boosting data availability for such an under-represented group as fungi. The meeting highlighted that macroecologists have worked hard in recent years to aggregate data on undersampled taxa that have been collected by specialized taxonomists or field biologists.…”

Late Quaternary climate change explains soil fungal community composition rather than fungal richness in forest ecosystems

“…Given the stronger effect of late Quaternary climate change on plant communities in temperate regions than in tropic-subtropical areas (Feng et al, 2016(Feng et al, , 2014, the late Quaternary climate change may similarly have a stronger effect on the soil fungal community (either directly or indirectly via impacts on plant communities) in temperate than in tropic-subtropical regions. In addition, contemporary environmental variables including climate, plant community structure, and soil physicochemical properties vary from temperate to tropic regions, and these changes result in different fungal biogeographical patterns across ecosystems (Andrew et al, 2018;Bahram et al, 2013;Tedersoo et al, 2012). For example, saprotrophic and ectomycorrhizal (EM) fungal communities have shown contrasting biogeographical patterns driven by different environmental variables from temperate to tropic forests (Andrew et al, 2018;Bahram et al, 2013;Tedersoo et al, 2012).…”