Cookies on Environmental Impact

Like most websites we use cookies. This is to ensure that we give you the best experience possible.


Continuing to use  means you agree to our use of cookies. If you would like to, you can learn more about the cookies we use.

Environmental Impact

From climate change to biodiversity loss - documenting human impacts on the environment

>>> Sign up to receive our Environmental Sciences newsletter, book alerts and offers <<<

News Article

Nitrogen pollution threatens biodiversity

New research highlights how little we know about the severity of this contaminant

Nitrogen (N) pollution is increasingly being recognised as a global threat to biodiversity. However, our understanding of the severity of its damage to ecosystems is limited, which in turn is hindering efforts to manage this contaminant.  In a paper recently published in the journal BioScience, a team of researchers studied the challenges associated with nitrogen.  

In order to assess the extent of recognized N-pollution effects on biodiversity in both aquatic and terrestrial ecosystems, the team surveyed 1,400 species in the continental U.S. that were listed as candidate, threatened or endangered under the US Endangered Species Act.  They found a total of 78 federally listed species that face threats from excess nitrogen pollution.  Their study demonstrated that N pollution has affected threatened species via a number of pathways, including direct toxicity, depleted oxygen resulting from excess fertilisation, as well as the spread of invasive species that outcompete local populations or exclude their food sources.  According to the authors, the direct attribution of declines to nitrogen pollution was hampered by “sometimes long and difficult-to-trace chains of causation from climate and atmospheric stressors to impacts.”

In recent years, the amount of nitrogen pollution has steadily increased.  This is due to fossil fuel burning, leguminous crop agriculture and fertilizer use, which has more than doubled the amount of global reactive nitrogen.  In the US, human-derived nitrogen additions are estimated to be fourfold greater than natural sources.  Despite this trend, the authors say that “existing laws and policies to protect biodiversity were largely developed before these threats were fully recognized.”

To highlight the complexity of tracing nitrogen impacts on listed species, the authors describe a case study of grasslands in California, which indicates that the impact of nitrogen on vulnerable species can be demonstrated “through a range of investigations at the atmosphere-ecosystem interface and the intersections of ecosystem, community and population ecology, involving both historical and comparative approaches,” which could help future management efforts.

According to the researchers, if regulatory structures can be effectively modernised to incorporate such approaches, efforts to mitigate the threat of nitrogen to species could be positive, because unlike global threats that can resist solutions at a local level, nitrogen pollution “can be more readily addressed within the boundaries of a single nation, region or watershed.”

Further information is available to subscribers of the Environmental Impact database.  For example, a search for nitrogen AND biodiversity AND pollution yields 695 results, while "pollution control" AND nitrogen AND ecosystem yields 192 results.  A selection of these is provided in the further reading section below.

Journal reference

Daniel L. Hernández, Dena M. Vallano, Erika S. Zavaleta, Zdravka Tzankova, Jae R. Pasari, Stuart Weiss, Paul C. Selmants, and Corinne Morozumi. Nitrogen Pollution Is Linked to US Listed Species Declines. BioScience, February 2016 DOI: 10.1093/biosci/biw003

Article details

  • Author(s)
  • Stephanie Cole
  • Date
  • 03 March 2016
  • Source
  • American Institute of Biological Science
  • Subject(s)
  • Biodiversity
  • Pollution