Arctic Heatwaves Could Significantly Influence the Isoprene Emissions From Shrubs

Warming climate in the Arctic is leading to an increase in isoprene emission from ecosystems. We assessed the influence of temperature on isoprene emission from Arctic willows with laboratory and field measurements. Our findings indicate that the hourly temperature response curve of Salix spp., the dominant isoprene emitting shrub in the Arctic, aligns with that of temperate plants. In contrast, the isoprene capacity of willows exhibited a more substantial than expected response to the mean ambient temperature of the previous day, which is much stronger than the daily temperature response predicted by the current version of the Model of Emissions of Gases and Aerosols from Nature (MEGAN). With a modified algorithm from this study, MEGAN predicts 66% higher isoprene emissions for Arctic willows during an Arctic heatwave. However, despite these findings, we are still unable to fully explain the high temperature sensitivity of isoprene emissions from high latitude ecosystems. Isoprene plays an important role in atmospheric chemistry and climate. As the climate warms, ecosystems release more isoprene into the air due to higher temperatures and changes in plant species composition. The Arctic is a hotspot for climate change. In this study, we investigated how temperature affects isoprene emissions from Arctic willow shrubs by conducting experiments in both the lab and the field. Our results show that the response of Salix spp. (willows) in the Arctic react to short-term temperature changes is similar to plants in temperate regions. Interestingly, the amount of isoprene that willows release responds strongly to the average temperature of the previous day. This response is much stronger than predicted by models. Considering the insights from our study, isoprene emissions from Arctic willows are much higher during Arctic heatwaves than previously thought. This study can help us understand how isoprene from Arctic willows will affect atmospheric composition and climate and contribute to corresponding feedbacks on the local climate. The hourly temperature response curve of Arctic Salix spp. is similar to temperate plants and is well represented by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) modelThe isoprene capacity of willows exhibited a pronounced response to the mean temperature of the previous dayMEGAN predicts a 66% higher isoprene emission for Arctic willows during an Arctic heatwave after incorporating the findings of this study