Theme 2 focuses on the question “Where does the life in the aerobiome come from, and how does composition respond to disturbances?” Understanding the factors driving aerobiome variation is essential to predicting its behavior and to determine linkages between aerobiome composition and ecosystem health.
Evidence shows that environmental and anthropogenic factors influence aerobiome composition. However, most studies of organismal components of the aerobiome have a limited biological, temporal and spatial scope that restricts mechanistic understanding; these analyses have described what is present, but do not comprehensively describe how and why. It has recently been suggested that wildfire smoke may contain high levels of microbes, potentially pathogens. Further, anthropogenic disturbances significantly modify air quality and aerobiome content. These examples illustrate the need for more mechanistic evaluations of conditions that perturb the aerobiome. In BROADN, we will systematically explore the relationship between biotic aerobiome and disturbance, sampling six regional sites that represent diverse environments subject to drought, fire, erosion, intensive agriculture, and land use change. Specific projects will examine hypotheses testing the impacts of prescribed burns, grazing, forest fires, and urbanization on aerobiome composition, relative to baseline seasonal measurements; and propose a modeling approach to assess microbial structure. Results will inform a basis for monitoring, predicting, and potentially modulating aerobiome content for desired outcomes.