Effects of simulated acidic rain on one species each of Pseudoparmelia, Usunea, and umbilicaria

Technical Report · Tue Dec 31 23:00:00 EST 1985

OSTI ID:5671558

Sigal, L L; Johnston, J W

The lichens Pseudoparmelia caperata (L.) Hale, Usnea of subfusca Stirt., and Umbilicaria mammulata (Ach.) Tuck. were exposed to simulated acidic rain with pH levels of 2.3, 3.0, 3.3, 4.3, or 5.6 and other ions in concentrations normally found in rain in the eastern United States. The pH levels of the most-acidic treatments (3.3, 3.0, 2.3) were similar to those found in fog, cloud water, and occasional rainfall events. The pH 4.3 and 5.6 treatments compared to average ambient conditions in the eastern and western United States, respectively, and caused no significant effects on photosynthesis. However, after the first week of treatment, significant effects of rain pH at the most-acidic treatments on gross photosynthesis were detected in P. caperata and U. mammulata, but not in U. of subfusca. Visible effects of injury were also observed and included bleaching, necrotic spots, and necrotic margins, which resembled damage seen in field populations of U. mammulata, the most-sensitive species.

• Research Organization: Oak Ridge National Lab., TN (USA). Environmental Sciences Div.
• OSTI ID: 5671558
• Report Number(s): PB-88-107099/XAB
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
560300 -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID RAIN
AIR POLLUTION
ALGAE
ATMOSPHERIC PRECIPITATIONS
BIOLOGICAL EFFECTS
CHEMICAL REACTIONS
ENVIRONMENTAL EFFECTS
FUNGI
LICHENS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
POLLUTION
RAIN
SYNTHESIS
TOXICITY