Vogler, D. R. 1980.
U.S.D.A., Forest Service, Pacific Southwest Region, San Francisco, CA 94111.
Page 132 in Abstracts of the 2nd Conference on Scientific Research in the National Parks, San Francisco, CA, 26-30 November 1979.
Elevated levels of ambient ozone were first reported in Sequoia and Kings Canyon National Parks in 1974. Subsequent investigations have revealed excesses of Federal and State ozone standards during the summer months at Park Ridge Lookout (2300 meters elevation) and at Lodgepole (2040 meters). Monitoring at nearby sites in the southern Sierra Nevada and at foothill and San Joaquin Valley locations reveals a daily pattern of pollutant transport into the mountains from urban areas to the west. Ozone has been implicated in the decline and death of conifers in the San Bernardino Mountains east of Los Angeles. Injury symptoms on ponderosa and Jeffrey pines -- identical to symptoms associated with ozone in southern California -- have been discovered near the monitoring sites in the National Parks, suggesting that a potential exists for severe ozone damage to these highly-scenic forests.