Exploring the global distribution of mycoheterotrophic plants

The distribution of symbiotic cheaters is driven by climatic preferences, not abundance of autotrophic hosts

GBIF-mediated data resources used : 32,752 occurrences
Burmannia championii
Burmannia championii observed in Taiwan by Chang Zhi Xiang. Photo via iNaturalist (CC BY-NC 4.0)

In mycorrhizal symbioses, plants exchange photosynthesized carbohydrates for mineral nutrients from fungi in the soil. Mycoheterotrophic plants, however, cheat—and obtain carbon from their fungal partners as well, sometimes leading to the complete loss of photosynthesis.

In this study, Dutch researchers explore the environmental preferences of mycoheterotrophic plants and drivers of their global distribution. Using GBIF-mediated occurrences of all known mycoheterotrophic species, the authors compile a large dataset with information on soil, climate, type of mycorrhizal fungi and autotrophic hosts.

Their analysis shows that mycoheterotrophic plants tend to avoid cold and highly seasonal climates. Plants associated with so-called arbuscular fungi are found in broadleaved tropical forests, whereas those preferring the company of ectomycorrhizal fungi occur in temperate regions—primarily needle-leaved forests.

This pattern appears to be driven by climatic factors—primarily temperature and precipitation—rather than abundance of specific autotrophic hosts from which the fungi-mediated nutrients are derived.

Original article

Gomes SIF, van Bodegom PM, Merckx VSFT and Soudzilovskaia NA (2019) Global distribution patterns of mycoheterotrophy. Global Ecology and Biogeography. Wiley. Available at: https://doi.org/10.1111/geb.12920