Search

Forests stands in the San Gabriel and San Bernardino Mountains of Southern California have been damaged severly by oxidants from Los Angeles smog. P.R. Miller was instrumental in isolating ozone as the principal toxic oxidant. On an estimated 25,000 acres of damaged forest land, ponderosa pine (Pinus ponderosa L.) is the most affected tree species according to Miller, et al., and J.R. Parmeter, Jr., et al. B.L. Richards, Sr., et al., reported that damage symptoms on pine are commonly exhibited by short, chlorotic needles, accelerated needle abscission, and high branch mortality. A feasibility study was conducted with aerial photography to attempt eventual development of a rapid survey technique for estimating the economic impact of oxidant damage on ponderosa pine in these mountains. Four aerial films and five photographic scales were employed. Anscochrome D-200 color film at scales of 1:7920 and 1:1584 was considered optimum for damage detection and evaluation, respectively.