As climate change intensifies, extreme drought events are becoming more frequent and severe, posing a significant threat to forest ecosystems. A recent study by researchers at the Institute of Applied Ecology, Chinese Academy of Sciences, has shed new light on how temperate forests respond to these changes.

The study focused on the role of ectomycorrhizal (ECM) fungi, symbiotic organisms that form a network of hyphae around plant roots, in helping trees withstand extreme drought and intense solar radiation. The researchers examined two common temperate tree species: Mongolian oak and Amur linden.

Their findings revealed that under increased drought intensity, both tree species experienced a significant decline in their ability to absorb nutrients. Additionally, the relative abundance of medium- to long-distance ECM fungi, which play a crucial role in nutrient acquisition, decreased.

These results support the energy limitation hypothesis, which suggests that the availability of energy, primarily in the form of carbohydrates produced by photosynthesis, limits the growth and activity of ECM fungi. This is in contrast to the functional compensation hypothesis, which proposes that ECM fungi can compensate for nutrient deficiencies by altering their functional strategies.

The study also highlights the importance of symbiotic relationships between trees and microbes in enhancing tree resilience to environmental stresses. By forming partnerships with ECM fungi, trees can access nutrients and water more efficiently, enabling them to better withstand drought conditions. 

The findings of this study, published in the journal Plant Cell and Environment, have important implications for forest management and conservation. By understanding the role of ECM fungi in helping trees cope with drought, scientists can develop strategies to promote forest regeneration and positive succession in the face of climate change.