Climate acts as an environmental filter to plant pathogens.

Area of Science:

• Ecology
• Plant Pathology
• Biogeography

Background:

• Climate influences plant-associated microbes, but its role in plant pathogen community assembly is less understood.
• Phytophthora species are significant plant pathogens with global distribution.

Purpose of the Study:

• To investigate the role of climate in the biogeographical assembly of Phytophthora communities across Europe.
• To determine whether climate or other factors like geography and tree diversity drive Phytophthora distribution.

Main Methods:

• Conducted surveys at over 250 sites across latitudinal and altitudinal gradients in Europe.
• Utilized ITS sequencing of river filtrates to detect Phytophthora communities.
• Employed mediation analysis to assess the influence of climate and other environmental factors.

Main Results:

• Climate was identified as the primary driver of Phytophthora biogeography, overriding factors like geography and tree diversity.
• Environmental filtering, particularly temperature, dominated over competitive exclusion in shaping Phytophthora communities.
• Northern regions showed selection for cold-tolerant species, while southern regions favored drought-tolerant species.

Conclusions:

• Climate, specifically temperature and precipitation, acts as a crucial environmental filter for Phytophthora community assembly in Europe.
• Cold temperatures are the main limiting factor for Phytophthora establishment across European landscapes.