Second year effects of clouds and ozone on red spruce seedlings

Conference · Tue May 01 04:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5729332

Pier, P A; Thornton, F C; McDuffie, C Jr ^[1]

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1. Tennessee Valley Authority, Muscle Shoals, AL (USA)

Potted native and phyton-grown red spruce seedlings were exposed for a second growing season to ozone and/or acid deposition in open-top field chambers on Whitetop Mountain, VA (elevation 1,680 m). Chamber treatments were (1) exclusion of clouds and 50% reduction in ambient ozone (COE), (2) ozone with clouds excluded (CE), and (3) exposure to clouds and ozone, as control chambers (CO), and (4) open plots (AA). No differences were detected among treatments for biomass accumulation or for chlorophyll and carotenoid concentrations. Phyton seedlings in AA and CO treatments maintained high photosynthetic rates through October, whereas rates in CE and COE decreased, suggesting that dormancy and winter hardiness were delayed in AA and CO, possibly making seedlings susceptible to early frosts. Respiration of both seedling types was higher for AA and CO throughout most of the growing season, which could lead to depletion of carbohydrates, and eventually to a reduction in growth and vigor of the seedlings over time due to air pollution.

• OSTI ID: 5729332
• Report Number(s): CONF-9007196--
• Conference Information: Journal Name: Plant Physiology, Supplement; (USA) Journal Volume: 93:1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACID RAIN
ATMOSPHERIC PRECIPITATIONS
BIOLOGICAL EFFECTS
CONIFERS
GROWTH
OZONE
PINOPHYTA
PLANT GROWTH
PLANTS
RAIN
SEEDLINGS
SPRUCES
TREES