Climate change and the ash dieback crisis

Area of Science:

• Ecology
• Forestry
• Pathology

Background:

• Climate change impacts species distribution and interactions, potentially increasing biodiversity loss.
• Emerging infectious diseases, like ash dieback (Hymenoscyphus fraxineus), pose significant threats to tree populations and forest ecosystems.
• Common ash (Fraxinus excelsior) is a vital European tree species facing severe mortality due to ash dieback.

Purpose of the Study:

• To investigate the interactive effects of climate change and ash dieback on the future spatial distribution of common ash.
• To model the potential uncoupling of host-pathogen interactions under various climate change scenarios.

Main Methods:

• Utilized two presence-only models to predict species distributions.
• Incorporated data from seven General Circulation Models and four emission scenarios.
• Analyzed the separate and combined influences of climate change on the ash tree and the Hymenoscyphus fraxineus pathogen.

Main Results:

• Climate change is projected to alter the spatial distribution of both common ash and Hymenoscyphus fraxineus.
• A potential uncoupling of host-pathogen distributions is predicted, leading to reduced disease transmission.
• Warming trends may shift ranges poleward, potentially alleviating disease pressure in southern and western Europe.

Conclusions:

• Climate change may mitigate the ash dieback crisis by creating spatial mismatches between the host and pathogen.
• Future forest management strategies should consider these climate-driven shifts in disease dynamics.
• The study highlights the complex interplay between climate change, host-pathogen interactions, and forest persistence.