Microbial Complexity and Diversity Enhance Microbial Necromass Nitrogen Sequestration Along a Latitudinal Gradient

Area of Science:

• Environmental Science
• Microbiology
• Geochemistry

Background:

• Human activities cause nitrogen enrichment in aquatic ecosystems, promoting microbial nitrogen cycling and the formation of microbial necromass nitrogen (MNN).
• The factors controlling MNN sequestration in estuarine and coastal wetlands are not well understood.

Purpose of the Study:

• To investigate MNN concentrations, sediment properties, and microbial traits across a latitudinal gradient.
• To determine the influence of abiotic and biotic factors on MNN sequestration in coastal wetlands.

Main Methods:

• Field sampling along a latitudinal gradient.
• Analysis of MNN concentrations, total nitrogen, and sediment properties.
• Assessment of microbial community diversity, abundance, network complexity, and stability.

Main Results:

• MNN concentrations varied significantly (0.02–1.25 mg g^-1), comprising 26–86% of total nitrogen.
• Fungal necromass predominated over bacterial necromass, indicating preferential preservation of fungal material.
• Total nitrogen was a stronger driver of MNN variation than temperature; sediment properties explained 47.8% of MNN variation.
• MNN correlated positively with microbial diversity, abundance, network complexity, and stability.

Conclusions:

• MNN is a critical nitrogen pool in coastal wetlands.
• Microbial complexity and diversity enhance MNN sequestration, offering a strategy to mitigate nitrogen pollution.
• Findings are significant for ecological restoration in global estuarine and coastal wetlands.