Microbial Taxa Distribution Is Associated with Ecological Trophic Cascades along an Elevation Gradient

Area of Science:

• Soil Ecology
• Microbial Ecology
• Biogeochemistry

Background:

• Elevational patterns of soil microbial diversity are of significant interest, but trophic dynamics and environmental drivers remain unclear.
• Understanding microbial community composition along elevation gradients is crucial for soil ecosystem functioning.

Purpose of the Study:

• To examine the distribution patterns of soil bacterial and fungal taxa along an elevation gradient on Changbai Mountain.
• To investigate the role of the oligotrophic-copiotrophic theory in explaining these elevational distribution patterns.

Main Methods:

• Sampling soil microbial communities across five vegetation types from 740 to 2,691 m above sea level.
• Analyzing relative abundance of major bacterial and fungal taxa.
• Classifying microbial taxa into oligotrophic and copiotrophic groups based on habitat characteristics and abundance patterns.

Main Results:

• Oligotrophic taxa (Acidobacteria, Gemmatimonadetes, Basidiomycota) peaked in mid-elevation dark-coniferous forests (oligotrophic habitats).
• Copiotrophic taxa (Proteobacteria, Actinobacteria, Ascomycota) were abundant in lower and higher elevation forests and alpine tundra (copiotrophic habitats).
• Specific classes within Proteobacteria and Basidiomycota, and groups within Acidobacteria, were classified as either oligotrophic or copiotrophic, supporting and expanding the theory.

Conclusions:

• The oligotrophic-copiotrophic theory effectively explains elevational distribution patterns of soil microbial taxa.
• This study confirms existing trophic classifications and extends the theory to finer taxonomic levels.
• Elevational changes in soil microbial communities are driven by habitat-specific resource availability and microbial life strategies.