Temperature-dependent trophic associations modulate soil bacterial communities along latitudinal gradients

Area of Science:

• Ecology
• Microbiology
• Environmental Science

Background:

• Latitudinal diversity patterns in microbial communities are complex and not fully understood.
• Existing hypotheses lack consensus on the primary drivers of these patterns.

Purpose of the Study:

• Investigate environmental heterogeneity and trophic interactions (protist-bacteria, virus-bacteria) shaping soil bacterial communities across a latitudinal gradient.
• Determine the influence of climate and soil properties on microbial community structure.
• Elucidate the role of biotic associations in microbial diversity patterns.

Main Methods:

• Large-scale field survey of soil microbial communities along a latitudinal gradient.
• Microcosm experiments to test the effects of environmental factors and biotic interactions.
• Analysis of bacterial, protist, and T4-like virus diversity and community structure.

Main Results:

• Microbial diversity showed kingdom-specific latitudinal trends: bacteria decreased, protists clumped, and T4-like viruses increased.
• Climatic and edaphic factors were key drivers, with climate effects intensifying at higher latitudes.
• Protist-bacteria associations exhibited a quadratic distribution, while virus-bacteria associations were significant only at high latitudes.
• Temperature was identified as a primary regulator of trophic associations.

Conclusions:

• Biotic interactions, particularly trophic associations, play a significant role in shaping bacterial communities along latitudinal gradients.
• Environmental factors and biotic interactions interact to influence microbial diversity patterns.
• This study reveals an underappreciated mechanism driving microbial community responses to environmental gradients.