Potential vulnerability of 348 herbaceous species to atmospheric deposition of nitrogen and sulfur in the United States
Clark CM, Simkin SM, Allen EB, Bowman WD, Belnap J, Brooks ML, Collins SL, Geiser LH, Gilliam FS, Jovan SE, Pardo LH, Schulz BK, Stevens CJ, Suding KN, Throop HL, Waller DM. 2019. Potential vulnerability of 348 herbaceous species to atmospheric deposition of nitrogen and sulfur in the United States. Nature Plants. 5(7):697-705
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.
- Type
- Journal Article
- Authors
- Clark, Christopher; Simkin, Samuel; Allen, Edith; Bowman, William; Belnap, Jayne; Brooks, Matthew; Collins, Scott; Geiser, Linda; Gilliam, Frank; Jovan, Sarah; Pardo, Linda; Schulz, Bethany; Stevens, Carly; Suding, Katharine; Throop, Heather; Waller, Donald
- Keywords
- critical load, deposition, herbaceous species, nitrogen, sulfur
- Subjects
- Ecological Framework: Air and Climate | Air Quality | Wet and Dry Deposition , Ecological Framework: Biological Integrity | Focal Species or Communities | Grassland/Herbaceous Communities , NPS.gov Subject Site: Air