Effects of ozone on seasonal nutrient and starch dynamics in foliage of young loblolly pine

Conference · Tue Jun 01 04:00:00 EDT 1993 · Bulletin of the Ecological Society of America; (United States)

OSTI ID:6202555

Baker, T R; Allen, H L ^[1]

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1. North Carolina State Univ., Raleigh (United States)

Young loblolly pine trees were exposed to ozone at below to above ambient concentrations in open-top chambers at a study site in the Piedmont of North Carolina. Seasonal dynamics of N, P, K, Ca, Mg, and starch were determined from foliage sampled at 3 week intervals during the first growing season and at six week intervals in succeeding seasons. Nutrient concentrations were generally higher in later flushes and in higher ozone treatments but the differences were significant only for K (200-300% of control) in first and second flush foliage during the first summer and for N (120-150% of control) in the second and third flush foliage in the first fall. Starch concentrations were not significantly affected until the following spring when higher ozone treatments had lower starch reserves ([approximately]50% of control). The seasonal patterns of accumulation and loss appear to have been affected by early abscission of foliage. Late season flushes in high ozone treatments showed accumulation of N when first flush foliage was abscising. Starch levels declined sharply prior to ozone induced premature abscission in the high ozone treatments and may have indicated the level of damage to the photosynthetic apparatus that led to premature abscission.

• OSTI ID: 6202555
• Report Number(s): CONF-930798--
• Conference Information: Journal Name: Bulletin of the Ecological Society of America; (United States) Journal Volume: 74:2
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CARBOHYDRATES
CONIFERS
DOSE-RESPONSE RELATIONSHIPS
GROWTH
LEAVES
NUTRIENTS
ORGANIC COMPOUNDS
OZONE
PINES
PINOPHYTA
PLANT GROWTH
PLANTS
POLYSACCHARIDES
REAGENTS
SACCHARIDES
SEASONAL VARIATIONS
STARCH
TREES
VARIATIONS