Tundra ecosystems are experiencing more frequent fires, a trend expected to continue throughout the 21st century. Post-fire recovery depends on complex interactions between microbial functional groups that drive nutrient cycling. This study uses a mechanistic model to show that the nitrogen cycle accelerates post-fire due to changes in niche space and microbial competition. Fast-growing bacterial heterotrophs replace slower-growing saprotrophic fungi in the soil, mineralizing organic matter and releasing nutrients. This process surpasses other nitrogen sources, boosting plant productivity recovery. The study highlights the importance of incorporating distinct microbial metabolisms in ecosystem models to understand post-disturbance recovery rates and long-term soil nutrient cycle feedback.

Nicholas J. Bouskill, Zelalem Mekonnen, Qing Zhu, Robert Grant, William J. Riley