Results/Conclusions Most efforts to predict the rates of microbially driven processes under future climates have extrapolated contemporary relationships between abiotic drivers and process rates, derived from either short-term lab studies under artificial conditions, or from large-scale patterns across resource or climate gradients. This approach assumes that the nature of these relationships will not change through time. However, recent studies have shown that microbial communities can acclimate to changing environments over time. For example, we recently found that the temperature sensitivity of soil respiration decreased in response to experimental warming in forest mineral soils. This mechanism may contribute to the ephemeral stimulation of respiration following experimental warming that has been observed at many sites, and has important implications for soil C responses to climate change. Other research suggests the ability of microbes to adapt to environmental change can be constrained by nutrient availability. In aquatic systems, the ability of bacteria to acclimate to temperature regimes, possibly through modifcations in cell wall structure, can be limited by P. Similarly, in soils, N availability can modify the balance of r vs K selected microbes, thus altering the ability of microbial communities to utilize short-lived pulses in C availability due to rhizodeposition or precipitation events. Ongoing research will elucidate the specific nature of biological adaptation and acclimation that will enable us to better constrain ecosystem response to global change and manage for preferential outcomes.