Accelerated leaf litter decomposition in freshwater streams is shaped by microbial succession and metabolism
Symbiotic relationships between plants and microorganisms stimulate ecosystem function and influence carbon allocation to higher trophic levels across ecosystem boundaries. However, the role of microbial metabolism in mediating decomposition rates is not well established and remains a challenge to address throughout community succession. Using a reciprocal transplant experiment, we present evidence that bacterial and fungal communities undergo community mixing throughout leaf litter decomposition in freshwater streams leading to distinct successional trajectories and accelerated leaf decomposition at home sites. By employing metabolic assays throughout leaf litter decomposition, we link shifts in microbial taxa with increasing metabolic capacity of fresh Alnus rubra leaves. This suggests that as decomposition progresses, more recalcitrant compounds may become more readily available for metabolism by a more diverse microbial consortium.