Global warming is affecting almost every ecosystem and region across the globe. Now, scientists have found it's even impacting plant-supporting soil fungi.
In this latest study, the researchers looked at how shifts in the tropical mountain cloud forest ecosystem would affect resident fungal species in Monteverde, Costa Rica. The scientists found that as the moist mountain soil dries out due to a warming climate, the fungi infrastructure that supports the abundant plant life will also change.
The impact on this ecosystem may be significant. If the higher-elevation soil becomes similar to lower-elevation soil (which is warmer and drier), it will spur the growth of the type of fungi flourishing at lower elevations that breaks down plant material. If this degradation of plant material escalates, it will release significantly increased amounts of carbon dioxide into the atmosphere.
While they make up less than 1 percent of the planet's land surface, tropical mountain cloud forests such as the one in Costa Rica contain about 20 percent of the world's plant species and 16 percent of its vertebrate species.
The cloud layer of these forests is rising due to global warming, leading to drier conditions. Consequently, these ecosystems are undergoing rapid shifts as plant species either become extinct or are forced to follow their optimal climates to higher elevations.
"These mountains provide a unique opportunity to predict how soil fungi will change in response to climate," said Caitlin Looby of the University of California. "The properties of these mountain soils are sensitive to the rising cloud layer. Our work demonstrates that fungal community composition shifts with elevation and with climatic factors that co-vary with belowground responses to elevation, such as temperature and moisture."
Soil fungi and plants have developed a mutually beneficial arrangement. For example, some fungi help plants by growing into their root cells and increase the root surface area available to absorb water and nutrients. In exchange, the roots give the fungi the sugars they carve. Other fungi help breakdown plant material, which releases carbon dioxide. The findings could mean big changes for these types of fungi.
"Any changes in climate could have important ecological consequences by potentially altering how these communities are structured and by altering the responses of important belowground processes that may mitigate or accentuate climate change," said Looby.
