Temperature as a driver of lichen microbiome dynamics: insights from lichen-enriched incubation experiment

AbstractLichens, a symbiotic alliance between fungi and photosynthetic partners, serve as a distinctive ecological niche hosting a diverse and microbiome. Investigating the impact of temperature on these microbiomes is essential for understanding their resilience to environmental changes, including global warming. In this study, we explored the effects of temperature on lichen-associated microbiomes through a 4-week controlled incubation experiment at three distinct temperatures, combined with metabarcoding techniques. Alpha diversity was consistently lower in the lichen-enriched microbiome compared to the original lichen and exhibited a gradual increase over time, except in the fungal community at high temperature, which showed an initial rise followed by a decline. Beta diversity analyses revealed that temperature had a more pronounced effect on community composition than incubation duration. Taxonomic shifts were more distinct in fungal communities than in bacterial communities across temperature conditions. The top five abundant OTUs at each temperature were identified, and random forest analysis highlighted OTUs most sensitive to temperature changes. This study provides valuable insights into temperature-sensitive bioindicators within the lichen microbiome and offers practical guidelines for isolating specific taxa under targeted environmental conditions, contributing to our understanding of lichen microbiome dynamics in a changing climate.