A better understanding of the mysterious function that fungus perform in ecosystems

four brown mushrooms
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Most people’s minds immediately jump to mushrooms when you mention “fungi,” however this is a misconception; most fungi do not generate mushrooms. Many of the estimated 3–13 million fungus species on Earth are so small that even a human eye would have a hard time seeing them.

They may be found just about anywhere, from dirt to the deepest parts of the ocean to the tissues of leaves in the rain forests. According to a new study published in the Annual Reviews of Ecology, Evolution, and Systematics, it is important to know how fungi migrate across a variety of spatial scales in order to understanding ecosystems, which in turn has consequences for agriculture and human health.

Mold growing in a refrigerator or mushrooms breaking down dead leaves in the forest both are classified as fungi, which has a bad reputation for being associated with death and decay. Associate professor of environmental studies at Dartmouth College and primary author Bala Chaudhary said that they often think of fungus as decomposers, but they are cryptic and perform many different things. Fungi may serve as nutrient cyclers, pathogens, and mutualists, coexisting with plants and other species for mutual benefit.

Human infections can also be caused by fungi. Like other soil-borne fungi, Coccidiodes spreads through the air if soil is disturbed or degraded. Coccidiodes is a fungus whose spores can induce a potentially fatal respiratory illness known as Valley fever or coccidioidomycosis if inhaled. Soil ecology, climate justice, and environmental health are all interconnected, and a greater knowledge of fungal dispersion can help provide light on how these subjects overlap.

Experts in agriculture, public health, and other sectors are interested in learning about fungal dispersal because it might help them forecast future agricultural pandemics and outbreaks of human disease, according to ecologist Dr. Anupam Chaudhary. What’s more, understanding fungal biodiversity and where species are spread on Earth relies heavily on knowledge of fungi’s dispersal mechanisms.

During her sabbatical in 2019–2020, Chaudhary worked with senior author Matthias Rillig, a professor of plant ecology at the Institute of Biology at Freie Universität Berlin, and members of his group to analyze the dispersal of fungus.

The researchers utilized a research-weaving technique, which involves reading journal articles and evaluating patterns in publication (also known as “bibliometrics”), to synthesize current knowledge on fungal dispersion and identify emerging research in this field. From 1951 to 2021, the group studied approximately 4,500 materials from over 1,200 sources. Almost all of the papers focused on studies of fungal dispersal conducted in the Americas, the UK, and China.

The majority of the published research on fungal dispersal dealt with fungal illness and its relationship to climate change; secondly, fungal diversity, communities, and mycorrhizal fungi; thirdly, the evolution of fungi using molecular approaches.

Theoretical connections between the relevance of geographical size and vectors of dissemination are presented as part of the investigation. From the microscopic to the landscape, they determined that fungal migration occurred on four distinct scales.

Mycelium, the root-like structure found in mushrooms, travels through the soil at the smallest size. Fungal pathogens may be spread on a wider scale by vectors such as small mammals and birds, as well as invertebrates like ants and earthworms, which can spread them through their droppings and nests. Large-scale fungal dispersal over landscapes and continents is driven by abiotic vectors like water and wind. Sediment carrying fungal spores is carried by rivers across continents, much as ocean currents and tides, precipitation, and even people contribute to the worldwide movement of fungus.

Climate change is making some parts drier and some wetter, which might affect the distribution of fungus, as explained by Chaudhary. Soil fungus can also be released into the air as a result of disturbance caused by agriculture, land development, and other human activities.

Fungi migration patterns may be altered by a combination of climate change and human-caused land use. The data supporting the links between the relative significance of movement vectors and geographical scale are few.  Additional information is required to understand the wide variety of fungus and the number of variables that influence their distribution in our environments.

Sources:

V. Bala Chaudhary et al. (2022). Fungal Dispersal Across Spatial Scales, Annual Review of Ecology, Evolution, and SystematicsDOI: 10.1146/annurev-ecolsys-012622-021604

https://phys.org/news/2022-12-cryptic-role-fungi-play-ecosystems.html