Future intensified heatwaves shift microbiomes in shallow eutrophic lakes from recoverable disturbance to persistent reorganization

This persistent reorganization was associated with stronger deterministic assembly, enhanced lineage-specific environmental filtering, contraction of the stabilizing microbial core, recovery biased toward cyanobacteria, and persistent changes in cross-domain microbial association structure. Importantly, these structural legacies were accompanied by persistent metabolic decoupling. The moderate heatwave temporarily enhanced net carbon fixation, whereas the severe heatwave suppressed gross primary production while elevating respiration, resulting in a persistent carbon deficit during recovery.

Collectively, our findings show that future intensified heatwaves can shift microbiomes in shallow eutrophic lakes from recoverable disturbance toward persistent reorganization while weakening carbon sink function, with broader implications for ecosystem resilience and inland water carbon cycling.</p>