show Abstracthide AbstractMicrobes such as Bacteria and Fungi play a critical role in the degradation of organic matter. Different combinations of microbial taxa result in different rates of decomposition, so predicting how climate change will affect microbial composition and function is fundamental to understanding future environments. However, the high number of microbial species in any given location constrains our ability to predict the fate of individuals following disturbance such as climate change. Here we present the results of a long-term manipulation experiment in which replicated grassland plots were subjected to drought and nitrogen fertilization within the range of predicted future conditions. We show that increases and decreases of leaf-litter microbes caused by global change simulations were significantly patterned by phylogenetic relatedness, resulting in communities more closely related than a random selection process would predict.