Protecting Natural Resources in the West Ellen Porter Air Resources Division – National Park Service WRAP IOC Meeting, Denver, CO July 28-29, 2003

NPS areas and resources in the West NPS role in protecting air quality and air quality related values in the West NPS mandates and policies for resource protection Ozone concentrations and trends Ozone effects NPS monitoring and research

NPS administers over 130 national parks, national monuments, and other units in the WRAP states. Of these, 36 are Class I air quality areas. NPS units in the West encompass a wide variety of resources and ecosystems, from high alpine tundra to deserts.

“…conserve the scenery and the natural and historic objects and wild life therein…as will leave them unimpaired for the enjoyment of future generations.” (NPS Organic Act) “Wilderness areas…shall be administered for the use of the American people in such a manner as will leave them unimpaired for future use and enjoyment as wilderness…” (Wilderness Act of 1964) “…preserve, protect and enhance the air quality in national parks, national wilderness areas, national monuments, national seashores, and other areas of special national or regional natural, recreational, scenic, or historic value.” (Clean Air Act as amended in 1977) “…declares as a national goal the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution.” (Clean Air Act as amended in 1977)

“…the Federal Land Manager should assume an aggressive role in protecting the air quality related values of land areas under their jurisdiction. In cases of doubt the land manager should err on the side of protecting the air quality-related values for future generations.” (Senate Report No , 95 th Congress, 1977)

Natural resources affected by NOx emissions include:  Visibility  Vegetation (ozone toxicity)  Lakes, streams, soils (acidification, fertilization, or eutrophication by deposition of nitrogen compounds)

Ozone and ozone effects in western national parks: Are certain western plant species sensitive to ozone? Do sensitive plant species occur in western parks? Are ozone concentrations high enough in the West to induce injury in sensitive vegetation? Are ozone concentrations increasing/decreasing? Has ozone injury been documented to vegetation in national parks in the West?

Are western plant species sensitive to ozone? Yes - sensitivity is determined by chamber studies, where plants are exposed to ozone at or near ambient concentrations and evaluated for symptoms. Plant sensitivity is species- specific; some species have defense mechanisms that protect against ozone injury, while others are very sensitive. NinebarkScouler’s willow Quaking aspen Do sensitive plant species occur in parks? Yes - nearly all western parks contain one or more ozone sensitive species. Chamber studies have found several dozen western species to be sensitive to ozone.

How does ozone affect sensitive species? - Visible symptoms Stipple (small red, purple, dark spots) Fleck (many small yellow spots) Chlorosis, bleaching (loss of green color) Necrosis (dead tissue) Premature leaf fall (senescence) - Physiological symptoms Reduced photosynthesis Reduced growth - Acute vs. chronic injury Acute - induced by high concentrations of ozone Chronic - induced by long-term cumulative doses of ozone Ozone-injured leafNormal leaf Aspen Ponderosa pine

Are ozone concentrations in the West high enough to induce injury in sensitive vegetation? NPS gaseous monitoring program:

Representative SUM06 ozone injury thresholds: Natural ecosystems 8-12 ppm-hr (foliar injury) Tree seedlings ppm-hr (reduction in growth) SUM06 = sum of all hourly concentrations greater than 60 ppb

Ozone injury surveys have been very limited in western national parks (to a few California parks and others). - California parks: Extensive injury to ponderosa pine and Jeffrey pine documented at Lassen Volcanic, Sequoia/Kings Canyon, and Yosemite NPs. Injury documented to understory species (mugwort, Mexican elder) at Sequoia/Kings Canyon NP. - Other Western parks: Injury to ponderosa pine documented at Saguaro NP. Injury to understory species at Bryce Canyon NP, Cedar Breaks NM, and Zion NP (UT). ponderosa pine healthy ozone-injured Has ozone injury been documented to vegetation in national parks?

Lassen Volcanic, Sequoia/Kings Canyon, and Yosemite NPs: foliar injury to 15-50% of ponderosa pines and Jeffrey pines at SUM06 = ppm-hr. Some areas of Lassen Volcanic NP had foliar injury to 20% of pines at SUM06 < 10 ppm-hr

Ozone and ozone effects in western national parks Are certain western plant species sensitive to ozone? YES Do sensitive plant species occur in western parks? YES Are ozone concentrations high enough in the West to induce injury in sensitive vegetation? YES Has ozone injury been documented to vegetation in national parks in the West? YES

How do ozone concentrations in national parks compare with nearby urban areas?

Do diurnal patterns of ozone differ from parks to nearby urban areas?

What has NPS done to better understand ozone and its effects? Extensive monitoring network in parks Inventory of ozone-sensitive plant species for all parks Limited identification of ozone injury in field Risk assessment for potential ozone injury in parks NPS information needs: Better ozone monitoring coverage Ozone sensitivity of additional western plant species Injury threshold information for western species Comprehensive field survey information