It is elemental: soil nutrient stoichiometry drives bacterial diversity

Area of Science:

• Soil Ecology
• Microbial Biodiversity
• Nutrient Cycling

Background:

• Plant biodiversity is known to be influenced by resource quantity and elemental stoichiometry.
• The impact of these factors on soil microbial diversity, particularly bacteria, is less understood.
• Understanding drivers of soil microbial diversity is crucial for ecosystem health and function.

Purpose of the Study:

• To investigate the role of soil resource stoichiometry (Carbon:Nitrogen:Phosphorus ratios) in shaping regional soil bacterial diversity.
• To evaluate the influence of land use, climate, and other biotic/abiotic factors on bacterial diversity patterns.
• To determine the primary drivers of soil bacterial diversity and composition at a regional scale.

Main Methods:

• Utilized a regional database of 179 locations across six ecosystem types in Scotland.
• Employed statistical modeling to analyze relationships between soil nutrients, land use, climate, and bacterial diversity.
• Assessed total carbon (C), nitrogen (N), and phosphorus (P) availabilities and their ratios.

Main Results:

• Soil bacterial diversity and composition were primarily driven by variations in soil resource stoichiometry (C:N:P ratios).
• Land use was identified as a significant factor influencing soil nutrient stoichiometry.
• Secondary drivers included climate, soil spatial heterogeneity, soil pH, root influence, and microbial biomass.

Conclusions:

• Nutrient stoichiometry is a powerful predictor of soil bacterial diversity and community composition at a regional scale.
• Land use plays an indirect role by altering soil nutrient stoichiometry.
• Findings highlight the importance of considering nutrient ratios alongside other factors for understanding soil microbial ecology.