Identifying environmental factors affecting the microbial community composition on outdoor structural timber.

Area of Science:

• Environmental microbiology
• Wood science
• Mycology

Background:

• Timber's susceptibility to microbial degradation limits outdoor applications.
• Limited knowledge exists on the prevalence and diversity of fungi damaging exterior structural timber.
• Understanding these microbial communities is crucial for timber durability.

Purpose of the Study:

• To investigate the fungal and bacterial community composition colonizing exterior structural timber.
• To identify key environmental factors influencing microbial community structure.
• To correlate specific microbial taxa with the severity of wood degradation.

Main Methods:

• DNA extraction from 46 decaying timber samples from Hamburg, Germany.
• PCR amplicon sequencing of fungal ITS2 and bacterial 16S rRNA genes.
• Analysis of environmental factors: wood species, C/N content, soil contact, and surrounding environment.

Main Results:

• Fungal and bacterial communities on timber resemble those found in forest deadwood.
• Perenniporia meridionalis and Dacrymyces species were frequently associated with severe wood damage.
• Wood species was the primary factor shaping both fungal and bacterial communities; environment influenced fungi, while soil contact impacted bacteria.

Conclusions:

• Wood species significantly influences both fungal and bacterial communities on timber.
• Environmental factors differentially shape fungal (surrounding environment) and bacterial (soil contact) communities.
• Microbial degradation of exterior timber is complex, influenced by both intrinsic wood properties and extrinsic environmental conditions.