Mycorrhizal fungi are ecosystem engineers that sustain plant life and help regulate Earth's biogeochemical cycles1-3. However, in contrast to plants and animals, the global distribution of mycorrhizal fungal biodiversity is largely unknown, which limits our ability to monitor and protect key underground ecosystems4,5. Here we trained machine-learning algorithms on a global dataset of 25,000 geolocated soil samples comprising >2.8 billion fungal DNA sequences. We predicted arbuscular mycorrhizal and ectomycorrhizal fungal richness and rarity across terrestrial ecosystems. On the basis of these predictions, we generated high-resolution, global-scale maps and identified key reservoirs of highly diverse and endemic mycorrhizal communities. Intersecting protected areas with mycorrhizal hotspots indicated that less than 10% of predicted mycorrhizal richness hotspots currently exist in protected areas. Our results describe a largely hidden component of Earth's underground ecosystems and can help identify conservation priorities, set monitoring benchmarks and create specific restoration plans and land-management strategies.

• Publication type
• Journal Article MeSH

Gradients in species diversity across elevations and latitudes have fascinated biologists for decades. While these gradients have been well documented for macroorganisms, there is limited consensus about their universality, shape and drivers for microorganisms, such as fungi, despite the importance of fungal diversity for ecosystem functions and services. We conducted a comprehensive survey of fungal species richness in forests across 17 elevational transects along a latitudinal gradient covering the continental scale of Europe. Diversity patterns along elevational and latitudinal gradients differed among fungal ecological guilds. Diversity of saprotrophs declined with elevation while ectomycorrhizal (ECM) fungal diversity peaked in mid-elevations. Moreover, the diversity of root endophytic fungi increased with latitude but did not change with elevation. Bayesian species distribution modeling suggests that fungal diversity is structured by deterministic rather than stochastic drivers. Importantly, ECM fungal diversity pattern persists even after accounting for the effects of environmental conditions. These results suggest that environmental conditions differentially shape the diversity of fungal guilds along elevational and latitudinal gradients, but this goes beyond soil and climatic factors in the case of ECM fungi. This study paves the way toward a better understanding of fungal diversity gradients across elevations and latitudes, with possible implications for macroecological theory, conservation and management.

• Keywords
• altitudinal and latitudinal gradients, biogeography, climate, ectomycorrhizal fungi, fungal diversity, join species distribution models, root endophytic fungi, saprotrophic fungi,
• MeSH
• Bayes Theorem MeSH
• Biodiversity * MeSH
• Fungi * physiology   MeSH
• Mycorrhizae physiology   MeSH
• Altitude * MeSH
• Geography MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Europe MeSH

Arbuscular mycorrhizal (AM) fungi are fundamental to planetary health, enhancing plant nutrient uptake, stabilizing soils, and supporting biodiversity. Due to their prevalence and ecological importance, AM fungi are critical to achieving the environmental targets within the United Nations (UN) Sustainability Development Goals (SDGs) framework, including SDG 15: Life on Land. Despite these fungi engaging in the most widespread and ancient plant-microbe symbiosis, many fundamental aspects of the biogeography of AM fungi remain poorly resolved. This limits our ability to understand and document these fungal species' contributions to preserving terrestrial life on Earth. Using the largest global dataset of AM fungal eDNA sequences, we highlight that > 70% of ecoregions have no available data generated from soil using AM fungal specific metabarcoding. Drawing attention to these severe data gaps can optimize future sampling efforts in key habitats. Filling these gaps and developing a more complete picture on the biogeographic distributions of AM fungal species will help to clarify their contributions to environmental targets.

• Keywords
• Life on Land, Sustainable Development Goals, arbuscular mycorrhizal fungi, biodiversity, conservation, ecoregion,
• MeSH
• Biodiversity MeSH
• Ecosystem MeSH
• Phylogeography MeSH
• Mycorrhizae * genetics   classification   physiology   MeSH
• United Nations MeSH
• Soil Microbiology MeSH
• Plants microbiology   MeSH
• Symbiosis MeSH
• Sustainable Development * MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Fungi are arguably the most diverse eukaryotic kingdom of organisms in terms of number of estimated species, trophic and life history strategies, and their functions in ecosystems. However, our knowledge of fungi is limited due to a distributional bias; the vast majority of available data on fungi have been compiled from non-tropical regions. Far less is known about fungi from tropical regions, with the bulk of these data being temporally limited surveys for fungal species diversity. Long-term studies (LTS), or repeated sampling from the same region over extended periods, are necessary to fully capture the extent of species diversity in a region, but LTS of fungi from tropical regions are almost non-existent. In this paper, we discuss the contributions of LTS of fungi in tropical regions to alpha diversity, ecological and functional diversity, biogeography, hypothesis testing, and conservation-with an emphasis on an ongoing tropical LTS in the Pakaraima Mountains of Guyana. We show how these contributions refine our understanding of Fungi. We also show that public data repositories such as NCBI, IUCN, and iNaturalist contain less information on tropical fungi compared to non-tropical fungi, and that these discrepancies are more pronounced in fungi than in plants and animals.

Los hongos son, posiblemente, el reino más diverso dentro del dominio Eukaryota en cuanto al número de especies estimadas, estrategias tróficas, ciclos de vida y funciones en los ecosistemas. No obstante, nuestro conocimiento sobre ellos es limitado debido a un sesgo de distribución: la mayoría de los datos disponibles provienen de regiones no tropicales. Se sabe mucho menos sobre los hongos de las zonas tropicales, y la mayor parte de los estudios realizados en estas áreas han sido de corta duración, centrados en la diversidad de especies fúngicas. Los estudios a largo plazo (LTS, por sus siglas en inglés), es decir, muestreos repetidos en una misma región durante períodos prolongados, son fundamentales para captar de manera completa la diversidad de especies en una zona. Sin embargo, los LTS de hongos en regiones tropicales son prácticamente inexistentes. En este artículo, analizamos las contribuciones de los LTS de hongos en zonas tropicales en relación con la diversidad alfa, la diversidad ecológica y funcional, la biogeografía, la prueba de hipótesis y la conservación, destacando un estudio LTS en curso en las montañas Pakaraima de Guyana. Mostramos cómo estos estudios enriquecen nuestra comprensión de los hongos. Además, demostramos que los repositorios públicos de datos como NCBI, UICN e iNaturalist contienen menos información sobre los hongos tropicales en comparación con los de regiones no tropicales, y que estas discrepancias son más marcadas en los hongos que en las plantas y los animales.

• Keywords
• Biodiversity, Biogeography, Citizen science, Conservation, Endemic fungi, Guiana shield, Taxonomy,
• Publication type
• Journal Article MeSH
• Review MeSH