Understanding cryptic role fungi play in ecosystems
When you say “fungi,” most people think of mushrooms, showy fruiting bodies, but most fungi do not produce mushrooms. It is estimated that there are approximately 3 to 13 million fungal species on Earth, many of which are microscopic in size.
New Hampshire [US], December 6 (ANI): Most people think of mushrooms when they hear the word “fungi,” yet most fungi do not produce them. There are an estimated 3 to 13 million fungal species on Earth, many of which are tiny in size.
They can be found in a variety of settings, including soils, rainforest leaf tissues, and deep oceans. According to a new review published in the Annual Review of Ecology, Evolution, and Systematics, understanding how fungi migrate over a range of spatial scales is vital for understanding ecosystems and has consequences for agriculture and human health.
Fungi, such as mould in a refrigerator or mushrooms that break down leaves on the forest floor, are frequently connected with death and decay. “We often think of fungus as decomposers, but they are cryptic and accomplish a wide range of things,” says lead author and Dartmouth associate professor of environmental studies Bala Chaudhary. “Fungi can also act as nutrient cyclers, pathogens, and mutualists, living in symbiotic relationships with plants and other creatures.”
Fungi can also be pathogens to humans. Coccidiodes are yet another soil-borne fungus that emits spores into the atmosphere as a result of land disturbance and soil degradation. Coccidiodes, also known as coccidioidomycosis, is a serious respiratory disease caused by inhaling the spores of this fungus.
A better understanding of fungal dispersal informs the intersecting disciplines of soil ecology, climate justice, and environmental health.
“Experts working in agriculture, public health, and many other fields are interested in understanding fungal dispersal, as this information can be used to predict things like future crop pandemics and outbreaks of human disease,” says Chaudhary, who is an ecologist. “Furthermore, studying how fungi disperse is central to understanding fungal biodiversity and where species are distributed on Earth.”
During her 2019-20 sabbatical, Chaudhary worked with senior author Matthias Rillig, a professor of plant ecology at the Institute of Biology at Freie Universitat Berlin, and members of his lab to co-author a study on how fungi disperse.
The team utilised a research-weaving approach that combines evaluating journal articles with assessing publishing trends, also known as “bibliometrics,” to synthesise existing material on fungal dispersal and identify emerging research in this field. From 1951 to 2021, the team evaluated over 4,500 documents from approximately 1,200 sources. The majority of the papers were about fungal dispersal research in the United States, the United Kingdom, and China.
The researchers found that scientific literature on fungal dispersal has focused on three topical areas: fungal disease, including climate change, which was the most prominent theme represented; fungal diversity, communities and mycorrhizal fungi, including soils and forests; and the evolution of fungi, including molecular methods.
As part of their analysis, the researchers pose theoretical relationships between the relative importance of vectors of dispersal and spatial scale and vectors of dispersal. They identified four scales of fungal movement from microscopic to landscape scales.
Tiny root-like structures of fungi at the mycelial level move through the soil on the smallest scale. Invertebrate animals, including micro/macroarthropods such as ants, and earthworms can transport fungi through their castings and nests, and small mammals and birds who may transport fungi via their feet, feathers, and digestive tracks serve as vectors for moving fungi at larger scales.
Abiotic vectors, such as water and wind, are responsible for fungal movement at the largest scale across the landscape and continents. Rivers transport sediment containing fungi propagules across continents, ocean currents and tides, and precipitation, as well as humans, all play a role in the global transit of fungi.
“With climate change, environments are getting dryer in some regions and wetter in others, factors that can change where fungi reside,” says Chaudhary. “Soil disturbance from agriculture, land development, and other human activities can also release soil fungi into the air.”
“Climate change, coupled with anthropogenic land use, can really impact the way that fungi move. The relative importance of movement vectors changes across spatial scale, but there’s very little data to support these relationships,” she says.
“More data is needed to understand the biodiversity of fungi and the many factors affecting their movement in our ecosystems.” (ANI)
