Bridging Rare and Abundant Bacteria with Ecosystem Multifunctionality in Salinized Agricultural Soils: from Community Diversity to Environmental Adaptation

Area of Science:

• Microbial Ecology
• Soil Science
• Environmental Microbiology

Background:

• Bacterial diversity and ecosystem multifunctionality (EMF) are influenced by environmental gradients.
• The relationship between bacterial diversity (taxonomic and phylogenetic, rare and abundant) and EMF in salinized soils remains understudied.

Purpose of the Study:

• To investigate the maintenance of bacterial diversity and its contribution to EMF in salinized agricultural soils.
• To differentiate the roles of rare and abundant bacteria, and their taxonomic and phylogenetic diversities, in driving EMF under salinity stress.

Main Methods:

• Utilized MiSeq sequencing to analyze bacterial communities in agricultural soils with varying salinity levels (0.09 to 19.91 dS/m).
• Employed multiple statistical analyses to assess bacterial community assembly, diversity patterns, and their correlation with EMF.
• Examined the influence of salinity on bacterial diversity and ecosystem functions.

Main Results:

• Rare bacteria exhibited tighter phylogenetic clustering and wider environmental tolerance compared to abundant bacteria.
• Abundant bacteria displayed higher functional redundancy and stronger phylogenetic niche conservatism.
• Salinity significantly modulated microbial community assembly, favoring variable selection for rare bacteria and a mix of dispersal limitation and variable selection for abundant bacteria.
• Rare bacterial taxonomic diversity and abundant bacterial phylogenetic diversity significantly contributed to EMF.
• Abundant bacterial community function, not diversity, significantly impacted soil EMF.

Conclusions:

• Salinity is a key factor shaping bacterial communities and their functional roles in agricultural soils.
• Rare and abundant bacteria possess distinct ecological strategies and contribute differently to ecosystem multifunctionality.
• Targeting specific bacterial diversity metrics (rare taxonomic, abundant phylogenetic) and functions is crucial for managing soil health and restoration in salinized environments.