There is compelling evidence (mostly from semi-arid regions) that ectomycorrhizal fungi (EMF) can play a critical role in drought tolerance. Some species of mycorrhizal fungi form common mycorrhizal networks (CMN) between individual trees of the same species, or even among species of widely different phylogenies. Tree species that host EMF species and readily form CMNs potentially improve the resistance and resilience of co-occurring tree species to drought by facilitating the mobilisation of key water resources between individual trees. But it is unknown how tree species and drought conditions interact to alter the formation of CMNs and what effect this has on tree resistance to drought in single and mixed tree species woodlands.
In addition to the potential to help improve tree drought tolerance, mycorrhizas are known to play a key role in forest decomposition pathways. Less well understood, is the relative importance of EMF compared with saprotrophic (decomposer) fungi on rates of decomposition in single and mixed species stands and how decomposer communities and decomposition rates might vary considering the tree species present. Different rates of decomposition have an important influence on levels of soil carbon and nutrient cycling, with feedback loops influencing tree growth rates.
The outcomes of this research will provide valuable insights for forest management, offering evidence-based guidelines for creating drought-resilient, productive woodlands, thereby supporting climate change adaptation and mitigation efforts.
This project is part of the Nature for Climate Fund.
Single tree species stands and mixtures of Scots pine and birch have been sampled in England covering an area with a breadth of risk of drought. Fieldwork for collecting soil samples from these plots is ongoing, with samples undergoing laboratory analysis and processing.
Drought microcosm experiments have been set up in the greenhouse to assess the role of Common Mycorrhizal Network (CMN) formation on levels of tolerance to drought in single and in mixed tree species contexts.
Laboratory simulations
Preliminary experimental work in the lab is underway to examine the ecological interactions between soil fungal groups to identify the factors driving competition and decomposition. The findings will contribute to carbon accounting models and inform forestry management strategies to create resilient and productive forests with enhanced carbon sequestration.
DEFRA
Natural England
Forestry Commission
The University of Manchester
University of Reading
Senior Forest Ecologist