Significant changes in soil microbial community structure and metabolic function after Mikania micrantha invasion

Area of Science:

• Ecology
• Microbiology
• Environmental Science

Background:

• Mikania micrantha invasion poses a significant threat to southeastern China's forest ecosystems.
• Soil microorganisms are crucial in regulating plant productivity, community dynamics, and ecosystem functions during invasions.
• The impact of Mikania micrantha on soil carbon, nitrogen, and phosphorus functional genes and associated environmental factors remains poorly understood, particularly in subtropical forests.

Purpose of the Study:

• To investigate the effects of Mikania micrantha invasion on soil nutrients and microbial communities in a subtropical forest.
• To explore changes in soil microbial community composition and metabolic function post-invasion.
• To identify key environmental factors influencing soil microbial functional gene expression.

Main Methods:

• Field study in Xiangtoushan National Forest Park, Guangdong Province.
• Metagenome sequencing to analyze microbial community structure and metabolic function.
• Analysis of soil nutrients, including total phosphorus, nitrate nitrogen, dissolved organic matter, soil organic matter, soil organic carbon, total nitrogen, and available phosphorus.

Main Results:

• Mikania micrantha invasion favored the growth of gram-positive bacteria (Gemmatimonadetes).
• Significant increases in soil microbial community structure and enzyme activity were observed post-invasion.
• Total phosphorus, nitrate nitrogen, and dissolved organic matter correlated strongly with soil microbial nitrogen functional genes.
• Soil organic matter, soil organic carbon, total nitrogen, and available phosphorus correlated strongly with soil microbial phosphorus functional genes.

Conclusions:

• Mikania micrantha invasion significantly alters soil nutrient profiles and microbial community composition in subtropical forests.
• The invasion creates a more favorable soil environment, potentially promoting further Mikania micrantha establishment.
• A positive feedback mechanism may exist, where altered soil conditions support the invasive species.