Exposure to airborne bacteria depends upon vertical stratification and vegetation complexity

Area of Science:

• Environmental microbiology
• Urban ecology
• Public health

Background:

• Biodiverse aerobiomes are linked to human health benefits.
• Ecological factors driving aerobiome exposure remain poorly understood.
• Limited research exists on near-surface urban green space aerobiome dynamics and vertical stratification.

Purpose of the Study:

• Investigate the spatio-compositional dynamics of urban green space aerobiomes.
• Determine the influence of habitat type and vertical position on aerobiome composition and complexity.
• Provide insights into aerobiome exposure relevant to public health and urban landscape management.

Main Methods:

• Columnar sampling of aerobiomes.
• Next-generation sequencing of the bacterial 16S rRNA gene.
• Geospatial and network analyses to assess spatio-compositional dynamics.

Main Results:

• Habitat type significantly impacts bacterial diversity and network complexity.
• Aerobiome vertical stratification and network complexity vary by habitat.
• Tree density, proximity, and canopy coverage correlate with higher aerobiome alpha diversity.
• Grassland aerobiomes show higher proportions of putative pathogens and vertical stratification compared to scrub.

Conclusions:

• Urban green space habitat type and height influence aerobiome composition and diversity.
• Findings highlight the importance of habitat-specific management for regulating aerobiome exposure.
• Results offer novel insights into urban ecosystems with potential public health implications.