This research examines how modern genetic and molecular methods are being used to study trees and their associated fungi in forest ecosystems. The findings have important implications for forest health and management in a changing climate. Impacts on everyday life: • Better understanding of tree diseases helps protect urban and forest trees that provide shade, clean air, and recreation • Improved tree breeding techniques lead to more resilient forests that better withstand climate change • Enhanced knowledge of beneficial fungi helps promote healthier trees and forests • More effective forest management practices support sustainable timber production • Better conservation strategies help preserve forests for future generations