Termites and flooding affect microbial communities in decomposing wood

• Logs protected from termites had distinct bacterial and fungal communities.
• Bacterial and fungal communities were affected by seasonal flooding.
• Bacteria appear to be more abundant in logs colonized by termites.

Wood properties and microbial community characteristics were compared between loblolly pine (Pinus taeda L.) logs protected or unprotected from termites (Blattodea: Rhinotermitidae: Reticulitermes spp.) and other arthropods for two years in seasonally flooded and unflooded forests in the southeastern United States. Significant compositional differences were observed between treatments and between flood patterns for both bacterial and fungal communities. Bacteria were 8–9-fold more abundant in unprotected logs compared to protected logs in both flooded and unflooded forests, with the greatest abundance seen in unprotected and unflooded logs. Wood nitrogen and lignin contents were unaffected by treatment, flood pattern or levels of termite damage visible in unprotected logs. We conclude that termites alter the composition of both bacterial and fungal communities and thus have the potential to indirectly affect wood decomposition and related processes through interactions with the microbial community.