Plant nutrient-acquisition strategies drive topsoil microbiome structure and function.

Area of Science:

• Soil ecology
• Microbiology
• Plant science

Background:

• Plant nutrient acquisition strategies influence soil processes and vegetation performance.
• Understanding the soil microbiome's response to vegetation changes is crucial for predicting ecosystem shifts under global change.

Purpose of the Study:

• To investigate the impact of different vegetation types and nutritional traits on topsoil microbiomes.
• To correlate vegetation traits, such as mycorrhizal types, with soil microbial community structure and function.

Main Methods:

• Analysis of topsoil microbiomes across 145 boreal and temperate sites in the Baltic region.
• Characterization of vegetation types, mycorrhizal associations (arbuscular mycorrhizal - AM, ectomycorrhizal - EM), and nitrogen-fixation.
• Assessment of microbial diversity, abundance of specific microbial groups, and enzyme activities.

Main Results:

• AM-dominated sites showed higher abundance of AM fungi, bacteria, fungal saprotrophs, and pathogens compared to EM-dominated sites.
• EM-dominated sites exhibited lower fungal diversity and bacteria:fungi ratios, linked to woody vegetation dominance and soil acidification.
• Differences in microbiome composition reflect distinct nutrient cycling rates and plant-soil feedback mechanisms between AM and EM systems.

Conclusions:

• Vegetation shifts, driven by global change and land use, can profoundly alter topsoil microbiome structure and function.
• Plant mycorrhizal type is a key determinant of soil microbial community composition and associated soil processes.
• The findings highlight the interconnectedness of vegetation, soil microbes, and ecosystem functioning.