Interpreting distance-decay pattern of soil bacteria via quantifying the assembly processes at multiple spatial...

Area of Science:

• Microbial Ecology
• Soil Science
• Biogeography

Background:

• The distance-decay pattern, where microbial similarity decreases with spatial separation, is well-established in soil microbiomes.
• However, the specific ecological processes driving this pattern remain incompletely understood.

Purpose of the Study:

• To investigate the bacterial community assembly processes across spatial scales in Northeast China maize fields.
• To quantify the contributions of dispersal, selection, and environmental factors to the soil microbiome's distance-decay pattern.

Main Methods:

• Utilized Illumina MiSeq sequencing to analyze bacterial community composition.
• Examined spatial turnover of microbial communities at multiple spatial scales.
• Quantified the influence of geographic, biotic, and abiotic factors on community structure.

Main Results:

• Bacterial community assembly processes shifted with spatial scale: homogenizing dispersal dominated small scales, while variable selection dominated large scales.
• Dispersal (homogenizing and limitation) explained 33% of spatial turnover.
• Deterministic selection processes were most influential (57%), with abiotic factors (soil pH) and biotic factors contributing significantly to variation.

Conclusions:

• The study provides a quantitative framework for understanding the soil microbiome's distance-decay pattern by analyzing assembly processes across spatial scales.
• Demonstrates the interplay of dispersal and selection in shaping soil bacterial communities.
• Offers insights into the roles of abiotic, biotic, and geographic factors in microbial biogeography.