Cruise Survey of Oxidant Air Pollution Injury to 'Pinus ponderosa' and 'Pinus jeffreyi' in Saguaro National Monument, Yosemite National Park, and Sequoia and Kings Canyon National Parks

摘要

The yellow pine populations in Saguaro National Monument, Yosemite National Park, and Sequoia and Kings Canyon National Parks were surveyed in 1986 to evaluate and quantify the extent and severity of ozone injury (chlorotic mottle) to foliage of ponderosa and Jeffrey pines. A total of 3780 trees were observed. Severity of ozone injury was quantified, using an approximate square root transformation of the percentage of foliage exhibiting chlorotic mottle in branches pruned from each tree. Foliage of different ages was examined separately. Of all trees examined at Saguaro National Monument, 15% had visible chlorotic mottle; at Yosemite, 28%; and at Sequoia and Kings Canyon, 39%. Severity of injury averaged very slight for all three parks, with least injury at Saguaro and greatest at Sequoia and Kings Canyon.