Vertical Stratification in Urban Green Space Aerobiomes

Area of Science:

• Environmental microbiology
• Aerobiology
• Public health

Background:

• Diverse environmental microbiomes are crucial for immune system development and pathogen defense.
• Urban green spaces, particularly vegetation and soil, are significant sources of airborne microbes (aerobiome).
• Limited research exists on the vertical dynamics of green space aerobiomes, despite potential public health implications.

Purpose of the Study:

• To determine vertical stratification in bacterial alpha diversity (richness and evenness) within an urban park aerobiome.
• To assess compositional differences (beta diversity) in airborne bacteria at various heights.
• To investigate altitudinal variations in potentially pathogenic and beneficial bacterial taxa.

Main Methods:

• Utilized a novel columnar passive petri dish sampling method at multiple heights (0.0, 0.5, 1.0, 2.0 m).
• Employed high-throughput sequencing of the bacterial 16S rRNA gene for microbial community analysis.
• Selected study sites using a geographic information system (GIS).

Main Results:

• Demonstrated significant vertical stratification in both alpha and beta diversity of airborne bacterial communities.
• Observed a general trend of decreasing bacterial diversity with increasing height.
• Found significant altitudinal differences in the abundance of potentially pathogenic and beneficial bacteria.

Conclusions:

• Vertical stratification of the aerobiome is evident in urban parkland, with diversity declining with height.
• Findings suggest that human exposure to airborne microbes may vary based on height and activity.
• Results provide a foundation for future research on aerobiome verticality and its public health and urban planning relevance.