Abstract
Soil microbial communities are vulnerable to global change factors and
land management decisions; these factors can therefore affect
microbially-mediated ecosystem functions. Increasingly, multiple stressors
are considered in investigations of ecological response to disturbances.
Here, we investigate how historical exposure to antibiotics affects the
soil microbial response to a subsequent temperature change. In-situ
antibiotic exposure initially increased soil respiration; however, this
effect diminished over time. A subsequent incubation experiment showed
that historical antibiotic exposure caused an acclimation-like response to
increasing temperature. This response was likely driven by a differential
response in the microbial community of antibiotic-exposed soils. Microbial
communities exposed to antibiotics tended to be dominated by
slower-growing, oligotrophic taxa at higher temperatures. Therefore,
historical exposure to one stressor is likely to influence the microbial
community to subsequent stressors. To predict the response of soils to
future stress, particularly increasing soil temperatures, historical
context is necessary.