A risk assessment framework for the future of forest microbiomes in a changing climate

Microbes inhabiting the above- and belowground tissues of forest trees and soils play a critical role in the response of forest ecosystems to global climate change. However, generalizations about the vulnerability of the forest microbiome to climate change have been challenging due to responses that are often context dependent. Here we apply a risk assessment framework to evaluate microbial community vulnerability to climate change across forest ecosystems. We define factors that determine exposure risk and processes that amplify or buffer sensitivity to change, and describe feedback mechanisms that will modulate this exposure and sensitivity as climatic change progresses. This risk assessment approach unites microbial ecology and forest ecology to develop a more comprehensive understanding of forest vulnerability in the twenty-first century. In this Perspective, the authors develop a risk assessment framework for forest microbiomes under climate change that unites microbial and forest ecology. They define processes that amplify or buffer microbial sensitivity and exposure risk and feedbacks that mediate impacts on microbial communities.