Microbial legacies alter decomposition in response to simulated global change

Area of Science:

• Ecology
• Microbiology
• Environmental Science

Background:

• Terrestrial ecosystem models often assume immediate microbial community resilience to environmental shifts.
• This assumption overlooks the potential long-term effects of microbial community history.

Purpose of the Study:

• To quantify the resilience of leaf litter microbial communities to altered precipitation and nitrogen availability.
• To investigate the role of microbial community legacies in ecosystem responses to global change.

Main Methods:

• Manipulating microbial composition in a global change experiment to decouple abiotic factors from microbial legacies.
• Analyzing fungal and bacterial community composition over three years.
• Measuring decomposition rates and utilizing metagenomic sequencing to assess microbial potential.

Main Results:

• Fungal composition was more influenced by the initial microbial inoculum than the experimental environment after one season, with this legacy persisting for three years.
• Bacterial communities exhibited greater resilience compared to fungal communities.
• Microbial functioning (decomposition) was not immediately resilient, depending on both current conditions and prior rainfall.
• Precipitation changes, but not nitrogen availability, altered bacterial carbohydrate degradation potential.

Conclusions:

• Microbial community legacies, particularly fungal, play a significant role in ecosystem responses to environmental change.
• Considering these microbial legacies is crucial for improving predictions of terrestrial ecosystem processes.
• The differential resilience of fungi and bacteria, and their varied responses to precipitation versus nitrogen, highlights the complexity of microbial community dynamics.