Bacterial community assembly processes mediate soil functioning under cadmium stress in the agroecosystem

Area of Science:

• Theoretical ecology
• Soil microbiology
• Environmental science

Background:

• Understanding community assembly effects on soil functioning under cadmium (Cd) stress is limited.
• Cadmium contamination poses a significant threat to agroecosystem health and microbial communities.

Purpose of the Study:

• To analyze bacterial community changes and soil functioning under varying Cd stress levels.
• To investigate the interrelationships between community assembly processes and soil functioning under Cd stress.

Main Methods:

• Amplicon sequencing to assess bacterial community structure and diversity.
• Quantitative PCR-based chip analysis for soil functional potential.
• Correlation and random forest analyses to determine interrelationships.

Main Results:

• Cadmium stress decreased bacterial diversity, network complexity, and stability, while increasing species turnover.
• Community assembly shifted towards dispersal limitation and homogeneous selection, with reduced community drift.
• Soil functional potential and stability were reduced, impacting carbon, nitrogen, phosphorus, and sulfur cycling.

Conclusions:

• Community assembly processes, including dispersal limitation and homogeneous selection, significantly influence soil functional potential under Cd stress.
• Cadmium stress impairs soil functioning by altering bacterial community structure and assembly processes.
• These findings offer insights into microbial-driven mechanisms governing soil functioning in contaminated environments.