Air quality at Pinnacles National Park
Most visitors expect clean air and clear views in parks. Pinnacles National Park (NP), California, is a spectacular landscape formed by ancient volcanoes and covered by mixed chaparral and oak woodlands. Air quality in the park is sometimes affected by pollution from mobile sources, road dust, agricultural activities, and burning. Air pollutants blown into the park from the San Francisco Bay Area to the north and beyond can harm natural and scenic resources such as soils, surface waters, plants, wildlife, and visibility. The National Park Service works to address air pollution effects at Pinnacles NP, and in parks across the U.S., through science, policy and planning, and by doing our part.
Visitors come to Pinnacles NP to enjoy spectacular views of the namesake rock pinnacles and chaparral-covered Gabilan Mountains. Park vistas are sometimes obscured by haze, reducing how well and how far people can see. Visibility reducing haze is caused by tiny particles in the air, and these particles can also affect human health. Many of the same pollutants that ultimately fall out as nitrogen and sulfur deposition contribute to this haze. Organic compounds, soot, dust, and wood smoke reduce visibility as well. Smoke from regional wildfires also contribute to particulate matter at the park. Significant improvements in park visibility have been documented since the late 1980’s. Overall, visibility in the park still needs improvement to reach the Clean Air Act goal of no human caused impairment.
- Reduced visibility, at times, due to human-caused haze from fine particles of air pollution;
- Reduction of the average natural visual range from about 140 miles (without pollution) to about 80 miles because of pollution at the park;
- Reduction of the visual range to below 50 miles on high pollution days.
Nitrogen and sulfur
Nitrogen and sulfur compounds deposited from the air may have harmful effects, including acidification, on soils, lakes, ponds, and streams. Steep-sided watersheds and very small uppermost streams, found in the park are typically associated with high acid sensitivity (Sullivan et al. 2011c; Sullivan et al. 2011d). However, site-specific data indicate that sensitivity to acidification is low in the park due to high availability of base cations in soils and streams that buffers acid deposition (Sullivan et al. 2001). Canyon live oak is the only identified acid-sensitive plant species found at Pinnacles NP.
Excess nitrogen can also lead to nutrient enrichment, a process that changes nutrient cycling and alters plant communities. While nitrogen deposition levels are low in the park, other areas of California, with elevated nitrogen levels have seen weedy annual grasses spreading to shrublands, grasslands, and coastal chaparral communities, similar to those present at Pinnacles NP (Fenn et al. 2003). The park is rated as highly sensitive to nutrient enrichment effects relative to other parks (Sullivan et al. 2011a; Sullivan et al. 2011b).
Healthy ecosystems can naturally buffer a certain amount of pollution, but as nitrogen and sulfur accumulate, a threshold is passed where the ecosystem is harmed. “Critical load” is a term used to describe the amount of pollution above which harmful changes in sensitive ecosystems occur (Porter 2005). Fortunately, estimated deposition levels at Pinnacles NP are low enough that no known critical-loads for park ecosystems are currently exceeded.
Visit the NPS air quality conditions and trends website for park-specific nitrogen and sulfur deposition information. PInnacles NP has been monitoring nitrogen and sulfur since 2000. Explore air monitoring »
At ground level, ozone is harmful to human health and the environment. Ground-level ozone does not come directly from smokestacks or vehicles, but instead is formed when other pollutants, mainly nitrogen oxides and volatile organic compounds, react in the presence of sunlight.
During the summer months, ozone levels in the park occasionally exceed the National Ambient Air Quality Standards set by the U.S. Environmental Protection Agency to protect public health. Ozone is a respiratory irritant, causing coughing, sinus inflammation, chest pains, scratchy throat, lung damage, and reduced immune system functions. Children, the elderly, people with existing health problems, and active adults are most vulnerable. When ozone levels exceed, or are predicted to exceed, health standards, Pinnacles NP staff post health advisories cautioning staff and visitors of the potential health risks associated with exposures to elevated levels.
Over the course of a growing season, ozone can also damage plant tissues making it harder for plants to produce and store food.It weakens plants making them less resistant to disease and insect infestations. A risk assessment that considered ozone exposure, soil moisture, and sensitive plant species concluded that plants in Pinnacles NP were at high risk of ozone damage relative to other national parks (Sullivan et al. 2001; Kohut 2007, 2004). The USDA Forest Service surveyed two forested sites near the park for ozone damage to plants and found a high level of injury at one site but none at the other site (Campbell et al. 2007). Some plants are more sensitive to ozone than others. Ozone-sensitive plants at Pinnacles NP include Artemisia douglasiana (mugwort), Sambucus mexicana (blue elderberry), and Apocynum cannabinum (Indian hemp). Search for more ozone-sensitive plant species found at Pinnacles NP.
Visit the NPS air quality conditions and trends website for park-specific ozone information. Pinnacles NP has been monitoring ozone since 1988. View live ozone and meteorology data and explore air monitoring »
Campbell, S. J., Wanek, R. Coulston, J. W. 2007. Ozone injury in west coast forests: 6 years of monitoring. General Technical Report. PNW-GTR-722. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 53 p. Available at https://www.fs.usda.gov/treesearch/pubs/27926.
Fenn, M. E., Haeuber, G. S., Tonnesen, J. S., Baron, J. S., Grossman-Clarke, S., Hope, D., Jaffe, D. A., Copeland, S., Geiser, L., Rueth, H. M., and Sickman, J. O. 2003. Nitrogen emissions, deposition and monitoring in the western United States. Bioscience 53: 391–403.
Jovan, S. 2008. Lichen bioindication of biodiversity, air quality, and climate: baseline results from monitoring in Washington, Oregon, and California. Gen. Tech. Rep. PNW-GTR-737. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 115 p. Available at https://www.fs.usda.gov/treesearch/pubs/29523.
Jovan, S. and McCune, B. 2005. Air quality bioindication in the greater central valley of California, with epiphytic macrolichen communities. Ecological Applications 15: 1712–1726. Available at https://www.fs.usda.gov/treesearch/pubs/21694.
Kohut, R. 2004. Assessing the Risk of Foliar Injury from Ozone on Vegetation in Parks in the San Francisco Bay Area Network. Available at https://irma.nps.gov/DataStore/Reference/Profile/2181550.
Kohut R.J. 2007. Ozone Risk Assessment for Vital Signs Monitoring Networks, Appalachian National Scenic Trail, and Natchez Trace National Scenic Trail. NPS/NRPC/ARD/NRTR—2007/001. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/ozone-risk-assessment.htm
Porter, E., Blett, T., Potter, D.U., Huber, C. 2005. Protecting resources on federal lands: Implications of critical loads for atmospheric deposition of nitrogen and sulfur. BioScience 55(7): 603–612. https://doi.org/10.1641/0006-3568(2005)055[0603:PROFLI]2.0.CO;2
Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011a. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/313. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/nitrogen-risk-assessment.htm
Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011b. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: San Francisco Bay Area Network (SFAN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/325. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2168733.
Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011c. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/349. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/acidification-risk-assessment.htm
Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011d. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: San Francisco Bay Area Network (SFAN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/376. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2170606.
Sullivan, T. J., Peterson, D. L., Blanchard, C. L. 2001. Assessment of Air Quality and Air Pollutant Impacts in Class I National Parks of California. National Park Service. 421 pp. Available at https://irma.nps.gov/DataStore/Reference/Profile/561620.
Sullivan T.J. 2016. Air quality related values (AQRVs) in national parks: Effects from ozone; visibility reducing particles; and atmospheric deposition of acids, nutrients and toxics. Natural Resource Report. NPS/NRSS/ARD/NRR—2016/1196. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/aqrv-assessment.htm.
Vasquez, E., Sheley, R. and Svejcar, T. 2008. Nitrogen Enhances the Competitive Ability of Cheatgrass (Bromus tectorum) Relative to Native Grasses. Invasive Plant Science and Management 1 (3): 287–295.