Rapid responses of soil microorganisms improve plant fitness in novel environments

Global change is challenging plant and animal populations with novel environmental conditions, including increased atmospheric CO2 concentrations, warmer temperatures, and altered precipitation regimes. In some cases, contemporary or “rapid” evolution can ameliorate the effects of global change. However, the direction and magnitude of evolutionary responses may be contingent upon interactions with other community members that also are experiencing novel environmental conditions. Here, we examine plant adaptation to drought stress in a multigeneration experiment that manipulated aboveground–belowground feedbacks between plants and soil microbial communities. Although drought stress reduced plant growth and accelerated plant phenologies, surprisingly, plant evolutionary responses to drought were relatively weak. In contrast, plant fitness in both drought and nondrought environments was linked strongly to the rapid responses of soil microbial community structure to moisture manipulations. ..., Lau and Lennon PNAS soil N and microbe dataThis csv file contains the microbial community composition and abundance data.Lau and Lennon PNAS microbe data.csvLau and Lennon PNAS N dataLau and Lennon PNAS plant data