Potential vulnerability of 348 herbaceous species to atmospheric deposition of nitrogen and sulfur in the United States

• Published in: Nature plants Vol. 5; no. 7; pp. 697 - 705
• Main Authors: Clark, Christopher M., Simkin, Samuel M., Allen, Edith B., Bowman, William D., Belnap, Jayne, Brooks, Matthew L., Collins, Scott L., Geiser, Linda H., Gilliam, Frank S., Jovan, Sarah E., Pardo, Linda H., Schulz, Bethany K., Stevens, Carly J., Suding, Katharine N., Throop, Heather L., Waller, Donald M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2019; Nature Publishing Group
• Subjects: 704/158/670; 704/158/672; Air Pollutants - chemistry; Air Pollutants - metabolism; Air Pollution; Air quality; Atmospheric pollution deposition; Biomedical and Life Sciences; Environmental Monitoring; Environmental policy; Indigenous species; Industrial pollution; Kinetics; Life Sciences; Magnesium; Nitrogen; Nitrogen - chemistry; Nitrogen - metabolism; Plant communities; Plant Sciences; Plants - chemistry; Plants - classification; Plants - metabolism; Species composition; Sulfur; Sulfur - chemistry; Sulfur - metabolism; Threatened species; United States; United States; United States > US
• ISSN: 2055-0278; 2055-0278
• DOI: 10.1038/s41477-019-0442-8

Atmospheric nitrogen and sulfur pollution increased over much of the United States during the twentieth century from fossil fuel combustion and industrial agriculture. Despite recent declines, nitrogen and sulfur deposition continue to affect many plant communities in the United States, although which species are at risk remains uncertain. We used species composition data from >14,000 survey sites across the contiguous United States to evaluate the association between nitrogen and sulfur deposition and the probability of occurrence for 348 herbaceous species. We found that the probability of occurrence for 70% of species was negatively associated with nitrogen or sulfur deposition somewhere in the contiguous United States (56% for N, 51% for S). Of the species, 15% and 51% potentially decreased at all nitrogen and sulfur deposition rates, respectively, suggesting thresholds below the minimum deposition they receive. Although more species potentially increased than decreased with nitrogen deposition, increasers tended to be introduced and decreasers tended to be higher-value native species. More vulnerable species tended to be shorter with lower tissue nitrogen and magnesium. These relationships constitute predictive equations to estimate critical loads. These results demonstrate that many herbaceous species may be at risk from atmospheric deposition and can inform improvements to air quality policies in the United States and globally. Fossil fuel and fertilizer use has led to increased nitrogen and sulfur pollution deposition in the United States, introducing mixed impacts on herbaceous species that could impact ecosystems as well as the individual plants.