Nitrogen falls in rain and snow on the ground where it is used by forest plants and microbes. New research through scientific collaboration led by the USDA Forest Service shows that more nitrogen from rain and snow is being made more streams than previously thought and flowing in the US and Canadian forests. The study, "Unprocessed atmospheric nitrate in the waters of the Northern Forest Region in the United States and Canada" was published this week in the journal Environmental Science & Technology .
Scientists found that some nitrate, which is a type of nitrogen that plants and microbes can use, moves too quickly from time to time for biological acceptance, resulting in "unprocessed" nitrate which avoids the filter. forest biology otherwise would be effective. The study combines pollutant emissions from a variety of sources and sometimes distant sources including industry, energy production, the transport sector and agriculture to forest health and water quality.
"Nitrogen is vital for the biological productivity of the planet, but it is ecology and aquatic pollutants when there are too many," said Stephen Sebestyen, hydrological research with the Northern USDA Forest Service Research Station located in Grand Rapids, Minn. and author of the study
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"From public land managers to timber tree owners, there is great interest in forest health and water quality. Our research identifies widespread pollutant effects, which undermine the efforts to manage nitrogen pollution."
Sebestyen and 29 co-people completed one of the largest and longest examinations to track unprocessed nitrate movement in forests. Scientists from a number of federal agencies and 1
"Normally we accepted that nitrate pollution would not take a large area through forest because the landscape would act as an effective filter," Sebestyen said. "This study shows that while we were not wrong about that, we wanted more information from us to get better information." Nitrates are generally used from forests, except where short windows are due to rain and snow runoff during higher flow events but important when unprocessed nitrate flows into streams; sometimes at unexpectedly high levels.
Too much nitrogen helps with forest decline and nuisance vegetation in lakes and ponds. Tree species have different levels of tolerance for nitrogen. Too much nitrogen can change forest composition and provide a pathway to non-native plants. "I am concerned about how air pollution affects forests and water thresholds," said Trent Wickman, Air Resources Specialist with the USDA Forest Service Eastern Region and co-author of the study. "There are a number of federal and state programs aimed at reducing nitrogen air pollution from vehicles and industrial sources. It is important to understand how effective the nitrogen comes from the air, but ends up on the ground. to assess the effectiveness of this pollution reduction "
Sebestyen and the co-authors of the study suggest that there is no need to monitor the forest vegetation due to nitrogen processed at the natural vegetation previously thought. issues.
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Stephen D. Sebestyen et al, Unprocessed atmospheric nitrate in the waters of the Northern Forest Region in the US and Canada, Environmental Science & Technology (2019). DOI: 10.1021 / acs.est.9b01276