The fungi and ecosystem

The fate of plants in the face of climate change is linked to fungi.

Fungi

In a new series of studies, researchers have revealed that fungi will be one of the most important determinants of ecosystem response to future climate change, helping certain types of plants weather droughts and floods by expanding their roots with food and water. But these organisms are not immune to climate change, they say.

The vegetation and forest cover of the earth depend on what is underground, where about 90% of all plants have an invisible support system represented by fungal organisms that form thin threads that connect the roots of plants and they bring food and water.

In contrast, plants provide a constant supply of carbon to fungi, and this symbiotic relationship is scientifically known as mycorrhizae.

Symbiotic relationships.

At the American Environmental Association's annual conference in August, researchers revealed the results of a number of new scientific studies on the role of fungi in protecting forests from the risks of climate change.

These studies have shown, according to the journal Science, that fungi can play a role - more than just establishing symbiotic relationships with the organisms that live around them - by having the ability to determine how ecosystems respond to climate change, through to their ability to help. the plants survive. Life in hotter and drier conditions.

However, other studies have confirmed that climate change could in turn disrupt symbiotic relationships and possibly accelerate the disappearance of their host plants.

According to the researchers, these fungal relationships come in two forms: arbuscular mycorrhizae, common in tropical forests, and some temperate forests as well as in fields and grasslands, in which fungi invade root cells and extend thin filaments called stringy mushrooms.

Ectomycorrhizal form in which fungi settle on the outer surface of the roots and their filament networks lead to the growth of fungi on moist forest soils.

Both types take up phosphorus and other plant nutrients, capture nitrogen from decomposing organic matter and help store carbon in the soil.

Selective help.

To learn about the importance of the symbiotic relationship between fungi and plants in the face of the effects of climate change, Catherine Geering, an environmental specialist at Northern Arizona University, and her colleagues planted seedlings of two groups of plants, the 'one with mushrooms and the other without them. , under different irrigation systems.

The researchers found that the ectomycorrhizal-like symbiotic relationship played an important role in drought tolerance.

It has also been observed that the type of symbiotic relationship prevalent in a particular region is linked to different types of trees and that this relationship determines how plants and entire ecosystems respond to climate change. Which has led scientists to wonder if the fungi themselves help determine the type of forest that grows in this area.

The fungi are under threat.

But these symbiotic relationships, as scientists claim, are not immune to the impact of climate change, as many studies mention.

Christopher Fernandez, a soil ecologist at the University of Minnesota who simulated the effect of warming and drought processes on fungi below the ground in northern hemisphere forests, confirmed that as the atmosphere heats up and dries up, the diversity of fungi decreases.

If the same disturbance occurs with the evolution of climate change, the number of plant species that successfully establish symbiotic relationships with fungi could decrease, which could starve trees of nutrients.

“The picture has become clearer now. We cannot really ignore the symbiotic relationships between fungi and plants in response to climate change, ”Matthias Relig, an ecologist at the Free University of Berlin, told the conference.