Climate change imposes stresses on microbes. This can have a big impact on the ecosystem processes they modulate. Stress tolerance traits often improve fitness in individual populations. Collectively, though, stress can have negative consequences to emergent community traits and ecosystem processes. I will discuss this paradox and propose ways to scale traits from individuals to ecosystems. Such scaling would reveal the mechanisms behind the microbial response: are stress tolerant microbes selected due to their competitive advantage or is stress tolerance acquired through evolution? An improved mechanistic understanding will enable better predictions of ecosystem processes in response to stress.
