Anthropogenic Noise and its Impacts on Plants, Pollinators, and People

Recent studies have shown that anthropogenic noise can have significant impacts on the species composition of ecosystems, plant physiology, animal behavior, and physiology in addition to acute and chronic impacts on human health and well-being. While past studies have examined impacts on different organisms separately and often in the lab, this study compared responses of pollinators, plants, and people exposed to two different locations (HT - high traffic and LT - low traffic) separated by 200 m on the Hollins University Campus. Average noise levels at the HT site were 10dB louder than at the LT site with the average maximum levels greater than 90bB. Unlike previous studies, we found no difference in the above and below-ground biomass between HT and LT plants nor was there any difference in leaf stomatal density after 58 days. Before harvesting, pollinator visitation rates at both sites (HT & HT) were videotaped simultaneously on five different occasions. Analysis of these videos revealed no difference in visitation rates by pollinators between the LT and HT sites; however, greater diversity in pollinator taxa was seen on marigolds at the LT site during the last pollination survey. To explore human responses, 44 participants spent 15 mins seated at both sites with a visual barrier blocking the roads. These exposures were separated by at least 24 hr, and participant blood pressure was measured, before and after the 15-min exposure. In addition, participants completed the PANAS survey after each exposure. Overall, participant blood pressure dropped after the 15 min exposure in both sites, with a significantly greater drop in systolic blood pressure found at the LT site. Participants also had lower “negative PANAS scores” at the LT site. This multilayered field study indicated that noise does matter and can have impacts on multiple species and processes within a system