- Air quality at Capitol Reef National Park
- Related references
Air quality at Capitol Reef National Park
Most visitors expect clean air and clear views in parks. Located in the heart of Utah’s red rock country, Capitol Reef National Park (NP) is filled with cliffs, canyons, domes, and bridges. The park enjoys relatively good air quality, but upwind emissions from disturbed drylands, urban areas, and industrial sources can degrade air quality. Air pollutants blown into the park 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 Capitol Reef NP, and in parks across the U.S., through science, policy and planning, and by doing our part.
Visitors come to Capitol Reef NP to view the area’s remarkable geology, including a dramatic monocline, large number of arches and natural bridges, high-walled canyons, and large rock domes. 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. Significant improvements in park visibility have been documented since the 2000’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 175 miles (without pollution) to about 130 miles because of pollution at the park
- Reduction of the visual range to below 90 miles on high pollution days
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.
Over the course of a growing season, ozone can damage plant tissues making it harder for plants to produce and store food. It also weakens plants making them less resistant to disease and insect infestations. An ozone risk assessment concluded that plants in Capitol Reef NP were at low risk of ozone injury (Kohut 2004). However, estimated ozone concentrations and cumulative doses at the park may be high enough to damage the leaves of sensitive vegetation under certain conditions (NPS 2012). Generally, dry conditions in the park during peak ozone concentrations are likely to limit ozone uptake by plants. However along streams and seeps, where conditions are wetter, plants may have higher ozone uptake and injury (Kohut et al. 2012). Some plants are more sensitive to ozone than others. Ozone sensitive plants in Capitol Reef NP include Amelanchier alnifolia (serviceberry), Populus tremuloides (quaking aspen), and Salix gooddingii (Goodding’s willow). Search for additional ozone-sensitive plant species found at Capitol Reef NP.
Visit the NPS air quality conditions and trends website for park-specific ozone information.
Nitrogen and sulfur
Nitrogen and sulfur compounds deposited from the air may have harmful effects, including nutrient imbalances and loss of biodiversity. 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). Nitrogen deposition exceeds the critical load for one or more park ecosystems (NPS ARD 2018).
Nitrogen deposition in the park is at levels known to affect diversity of plants and lichens (Pardo et al. 2011). Although nitrogen is necessary for plants to grow, too much nitrogen can cause nutrient enrichment, a process that disrupts the balance of plant communities, promoting the growth and spread of fast-growing invasive grasses (e.g., cheatgrass) and forbs (e.g., Russian thistle) at the expense of native species (Brooks 2003; Schwinning et al. 2005; Allen et al. 2009). Plants in arid shrubland and grassland ecosystems are particularly vulnerable to changes caused by nitrogen deposition. Widespread invasive grasses can increase fire risk (Rao et al. 2010; Balch et al. 2013) and affect plant biodiversity. A study rated ecosystems at Capitol Reef NP as highly sensitive to nutrient enrichment from nitrogen deposition relative to other national parks (Sullivan et al. 2011a; Sullivan et al. 2011b). Excess nitrogen may also increase water use in plants like big sagebrush (Inouye 2006).
Nitrogen, together with sulfur, can also acidify surface waters and soils. Given the abundance of base cations in park soils and rocks, surface waters at Capitol Reef NP are generally well-buffered from acidification (Binkley et al. 1997). Some plants are sensitive to acidification, search for acid-sensitive plant species found at Capitol Reef NP.
Visit the NPS air quality conditions and trends website for park-specific nitrogen and sulfur deposition information.
Mercury and toxics
Airborne mercury, and other toxic air contaminants, when deposited are known to harm birds, salamanders, fish and other wildlife, and cause human health concerns. These substances enter the food chain and accumulate in the tissue of organisms causing reduced reproductive success, impaired growth and development, and decreased survival.
A study of mercury in fish (Eagles-Smith et al. 2014) indicates that mercury levels in individual fish from the Fremont River at Capitol Reef NP are elevated. Speckled dace, a small insect eating prey fish, were sampled in the park, and contained some of the highest mercury concentrations measured in the study. These fish exceeded mercury levels measured in many of the largest predatory fish. Mercury concentrations in 49% of speckled dace sampled exceeded the threshold for reproductive impairment in fish, and 98% exceeded the toxicity threshold for sensitive birds (Eagles-Smith et al. 2014). Speckled dace are not consumed by humans and therefore the human health risk was not assessed. The source of mercury in fish at the park is unknown, but similar results were found nearby at Zion NP.
Allen, E. B., L. E. Rao, R. J. Steers, A. Bytnerowicz, and M. E. Fenn. 2009. Impacts of atmospheric nitrogen deposition on vegetation and soils in Joshua Tree National Park. Pages 78-100 in R. H. Webb, L. F. Fenstermaker, J. S. Heaton, D. L. Hughson, E. V. McDonald, and D. M. Miller, editors. The Mojave Desert: ecosystem processes and sustainability. University of Nevada Press, Las Vegas, Nevada, USA.
Allen, E. B. and L. H. Geiser. 2011. North American Deserts. In L.H. Pardo, M.J. Robin-Abbott and C.T. Driscoll (Eds.). Assessment of Nitrogen Deposition Effects and Empirical Critical Loads of Nitrogen for Ecoregions of the United States. General Technical Report NRS-80. U.S. Forest Service, Newtown Square, PA. pp. 133-142. Available at: http://nrs.fs.fed.us/pubs/38109.
Balch, J. K., Bradley, B. A., D'Antonio, C. M., Gomez-Dans, J. 2013. Introduced annual grass increases regional fire activity across the arid western USA (1980-2009). Global Change Biology 19: 173-183.
Binkley et al. 1997. Status of Air Quality and Related Values in Class I National Parks and Monuments of the Colorado Plateau. Chapter 8. Capitol Reef National Park. National Park Service, Air Resources Division, Denver, CO. Available at https://irma.nps.gov/DataStore/Reference/Profile/167034.
Bowman, W. D., J. S. Baron, L. H. Geiser, M. E. Fenn, E. A. Lilleskov. 2011. Northwestern Forested Mountains. In L.H. Pardo, M.J. Robin-Abbott and C.T. Driscoll (Eds.). Assessment of Nitrogen Deposition Effects and Empirical Critical Loads of Nitrogen for Ecoregions of the United States. General Technical Report NRS-80. U.S. Forest Service, Newtown Square, PA. pp. 133–142. Available at: http://nrs.fs.fed.us/pubs/38109.
Brooks, M. L. 2003. Effects of increased soil nitrogen on the dominance of alien annual plants in the Mojave Desert. Journal of Applied Ecology. 40:344-353.
Eagles-Smith, C.A., Willacker, J.J., and Flanagan Pritz, C.M., 2014, Mercury in fishes from 21 national parks in the Western United States—Inter and intra-park variation in concentrations and ecological risk: U.S. Geological Survey Open-File Report 2014-1051, 54 p. http://dx.doi.org/10.3133/ofr20141051.
Inouye, R. S. 2006. Effects of shrub removal and nitrogen addition on soil moisture in sagebrush steppe. Journal of Arid Environments. 65: 604-618.
Kohut, B. 2004. Assessing the Risk of Foliar Injury from Ozone on Vegetation in Parks in the Northern Colorado Plateau Network. Available at https://irma.nps.gov/DataStore/Reference/Profile/2181489.
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
Kohut, B., C. Flanagan, E. Porter, J. Cheatham. 2012. Foliar Ozone Injury on Cutleaf Coneflower at Rocky Mountain National Park, Colorado. Western North American Naturalist 72(1): 32-42.
[NPS] National Park Service. 2014. Mercury in Fish from 21 National Parks across the Western U.S. and Alaska. Factsheet. Available at https://irma.nps.gov/DataStore/Reference/Profile/2208703.
Pardo, L. H., M. J. Robin-Abbott, C. T. Driscoll, eds. 2011. Assessment of Nitrogen deposition effects and empirical critical loads of Nitrogen for ecoregions of the United States. Gen. Tech. Rep. NRS-80. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 291 p. Available at: http://nrs.fs.fed.us/pubs/38109.
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
Rao, L. E., E. B. Allen, and T. Meixner. 2010. Risk-based determination of critical nitrogen deposition loads for fire spread in southern California deserts. Ecological Applications 20: 1320-1335.
Schwinning, S., B. I. Starr, N. J. Wojcik, M. E. Miller, J. E. Ehleringer, R. L. Sanford. 2005. Effects of nitrogen deposition on an arid grassland in the Colorado plateau cold desert. Rangeland Ecology and Management. 58: 565-574.
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: Northern Colorado Plateau Network (NCPN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/313. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2168722.
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: Northern Colorado Plateau Network (NCPN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/366. National Park Service, Denver, Utah. Available at https://irma.nps.gov/DataStore/Reference/Profile/2170594.
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.