Interspecific Plant Interactions Reflected in Soil Bacterial Community Structure and Nitrogen Cycling in Primary...

Area of Science:

• Ecology
• Microbial Ecology
• Plant-Soil Interactions

Background:

• Plant-microbe interactions are key drivers of ecosystem succession.
• Previous studies treated microbial communities as a black box, limiting understanding of plant-soil dynamics.

Purpose of the Study:

• To investigate how shifts from early successional Sitka alder to late successional Sitka spruce affect soil bacterial communities and nitrogen cycling.
• To determine the specific impact of Sitka spruce on alder-conditioned soils and associated microbial communities.

Main Methods:

• Examined bacterial community structure and nitrogen cycling in alder-conditioned soils from a glacial forefield.
• Conducted a microcosm experiment using leachate from Sitka spruce to assess its impact on alder-conditioned microbiomes and nitrogen cycling.

Main Results:

• Increasing abundance of Sitka alder selected for specific bacterial taxa.
• Sitka spruce leachate significantly altered microbial community composition, reducing alder-enriched taxa, including bacterial symbionts.
• These effects were specific to Sitka spruce and influenced ammonium availability.

Conclusions:

• Sitka spruce actively modifies soil microbial communities and nitrogen cycling, influencing ecosystem succession.
• Plant-microbe interactions, particularly with late-successional species like Sitka spruce, are crucial for understanding interspecific plant interactions and ecosystem development.