Warming responses of microbial respiration emerge from spatially structured species interactions
Year: 2026
Type: preprint
Abstract: Microbial communities are the main drivers of global carbon cycling. Yet, predicting their respiratory responses to warming is challenging because the underlying mechanisms remain elusive. Here, we developed a spatially explicit model, integrating single-cell metabolism with metabolic exchange and endogenous heat production, to disentangle the mechanisms driving community-level temperature responses. We reveal that mutualism amplifies respiratory temperature sensitivity compared to isolated taxa, as exchanged metabolites sustain a secondary growth phase with higher respiratory demand, and this phase creates disproportionately large CO 2 emissions under warming (apparent activation energy E a increases from 0.65 to 0.77 eV). Spatial structure amplifies this further through threshold effects, whereby diffusion limitation shifts from constraining to enabling mutualistic benefits as metabolic rates increase with temperature ( E a increases to 1.18 ± 0.09 eV). Endogenous heat production drives additional amplification through positive feedback between local temperature rises and resource turnover rates ( E a further increasing to 1.78 ± 0.14 eV). Collectively, our results demonstrate that community-level temperature responses are not determined by enzyme kinetics alone but emerge from the interplay of ecological, physical, and metabolic interactions. Our model provides a general framework for understanding the combined effects of the underlying mechanisms on microbial temperature responses. Future climate–carbon models should incorporate these considerations to improve predictions. Graphical abstract
Institution: KU Leuven
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Climate action
Open Access status: green
OpenAlex ID: W7222664960