Although noise can change from person to moment, it has a more lasting effect on trees and plants.
A new study by Cal Poli reveals that human noise pollution affects the diversity of plant life in the ecosystem even after noise removal. This is the first study to investigate the long-term effects of noise on plant communities. It was published in Proceedings of the Royal Society B..
In a study conducted twelve years ago near a natural gas well in New Mexico, researchers found that there were 75% fewer pine nuts in noisy places than in quiet ones. This was most likely due to the noise that drove away the forest of Woodwood shrubs that plant thousands of pine seeds while storing them to eat during the winter months.
The research team recently returned to those locations to find out if the pine nuts have recovered over time.
As companies change locations where they use noisy compressors to help produce natural gas, some of the previously noisy locations have become quiet. There were fewer seedlings and seedlings in these areas compared to locations where no compressors were added to the gas extraction cushion. The reduction of seedlings comes from the time when the location was noisy, but the reduction of seedlings shows that the seeds of pine pine have not yet sprouted after removing the noise.
“The effects of human noise pollution are increasingly entering the structure of these forest communities,” said biology professor and senior author Clint Francis. “What we see is that noise removal does not necessarily lead to an immediate recovery of environmental function.”
Although it is possible that the pine nuts decreased due to the lack of production possibilities, it is more probable that the Woodhouse bushes did not return to the former noisy area, and so did the planting of seeds.
“Some animals, like juices, have an episodic memory,” said Jennifer Phillips, a lead author who worked on the project while a postdoctoral fellow in Cal Polio and is now a professor at Texas A&M-San Antonio. “Animals like grazing juice that are sensitive to noise learn to avoid certain areas. It may take time for the animals to rediscover these previously noisy areas, and we don’t know how long that could take. “
The researchers also found differences in spruce seedlings and flowering plant communities depending on the current noise level and whether the noise level has recently changed due to the movement of noisy compressors. Locations with higher noise had fewer spruce seedlings and different types of plants than quiet locations. Due to the complexity of the ecosystem, the cause of these changes is still unknown.
“Our results reveal that plant communities change in many ways with exposure to noise,” Francis said. “We have a decent understanding of how and why foundation trees like pine trees are affected by noise from our previous work with strains, but we also see great changes in plant communities through changes in the abundance of shrubs and annuals. These changes probably reflect the impact of noise on plant-eating animals, such as deer, elk and various insects, plus many pollinators that are important for plant reproduction. In essence, our research shows that the effects of noise are far-reaching and resonate throughout the ecosystem through many species. “
Future studies may provide a more accurate view of how noise causes these changes in the ecosystem. Researchers want to know more about which herbivores, seed dispersants and pollinators avoid or are attracted to noise and how changes in the behavior of insects and animals affect plant communities.
Based on patterns from more than a decade of ecosystems facing noise pollution, the evidence suggests that plant communities should take a long time to recover from the effects of human noise. Still, co-author and lead botanist Sara Termondt, a research subsidiary of Cal Poli, emphasizes the need to understand the full and lasting cost of noise. “Continuing to look at long-term changes in floristic stocks will, over time, clarify whether communities will eventually recover after long periods of noise pollution, even when removed from the landscape,” she said.
When changes in plant communities are viewed along with growing evidence of noise problems created by animals, it is increasingly difficult to ignore the near absence of noise regulations across the United States
Reference: April 13, 2021, Proceedings of the Royal Society B..
DOI: 10.1098 / rspb.2020.2906
Funding: Department of Natural Sounds and Night Sky in the National Park, National Science Foundation, William and Linda Frost Foundation of Cal Poli College of Natural Sciences and Mathematics