Analysis of the relationships among O3 uptake, conductance, and photosynthesis in needles of pinus ponderosa

Technical Report · Fri Jan 01 00:00:00 EST 1993

OSTI ID:5582636

Weber, J A; Clark, C S; Hogsett, W E

The determination of conductance and photosynthesis to ozone uptake is important for the prediction of the long-term response of trees to ozone exposure. The authors studied the effects of O3 uptake on conductance (gwv) and photosynthesis (A) in needles of ponderosa pine (Pinus ponderosa) seedlings exposed for 70 days to one of three O3 regimes -- Low-O3, High-O3, and Low/High-O3. Seedlings exposed to charcoal-filtered air served as controls. Total O3 exposures, expressed as ppm-h (the sum of the average hourly concentration to ppm over the exposure period), were 77, 135, 105, and 4 for the Low-O3, High-O3, Low/High-O3, and control treatments, respectively. Conductance declined to about 60% of the value in control seedlings by Day 6 in seedlings in the High-O3 treatment and by Day 37 in seedlings in the Low/High-O3 treatment, but did not decline at all in seedlings in the Low-O3 treatment.

• Research Organization: Environmental Protection Agency, Corvallis, OR (United States). Environmental Research Lab.
• OSTI ID: 5582636
• Report Number(s): PB-94-113719/XAB; EPA-600/J-93/441
• Resource Relation: Other Information: Pub. in Tree Physiology 13, 157-172(1993)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
OZONE
ENVIRONMENTAL EFFECTS
AIR FILTERS
AIR POLLUTION CONTROL
BIOMASS
CHARCOAL
EXHAUST GASES
PHOTONS
PHOTOSYNTHESIS
PINES
PROBABILISTIC ESTIMATION
REGRESSION ANALYSIS
SEEDLINGS
STATISTICAL DATA
STOMATA
TREES
UPTAKE
VARIATIONS
ADSORBENTS
BOSONS
CHEMICAL REACTIONS
CONIFERS
CONTROL
DATA
ELEMENTARY PARTICLES
ENERGY SOURCES
EQUIPMENT
FILTERS
FLUIDS
GASEOUS WASTES
GASES
INFORMATION
MASSLESS PARTICLES
MATHEMATICS
NUMERICAL DATA
OPENINGS
PHOTOCHEMICAL REACTIONS
PINOPHYTA
PLANTS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
RENEWABLE ENERGY SOURCES
STATISTICS
SYNTHESIS
WASTES
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)