Comparison of the response of mature branches and seedlings of Pinus ponderosa to atmospheric pollution

Technical Report · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6142728

Anderson, P D; Houpis, J L.J.; Benes, S E; Neuman, L E; Loeffler, T; Phelps, S P

Since completion of exposure-facility-construction activities in October 1989, most of our effort has focused on conducting the pollutant exposures and collecting plant-tissue response data. The winter and early spring months were spent calibrating the ozone generation and distribution system. Several modifications were made to the original fumigation system to mitigate problems with ozone generation. Acid-rain exposures were conducted as a series of rain events from June through August. Routine measurements of growth, foliage water potential, and soil-water content have been made since March. Intensive physiological measurements, including gas exchange, foliar-nutrient concentration, pigmentation, and antioxidant-enzyme activity were made in November (pre-exposure measurements), March, and July. Initial analyses fail to indicate significant ozone or acid-rain effects on many parameters. The gas-exchange data indicated that there may be a significant reduction in photosynthesis by mature-branch tissue in July due to ozone. The rates of transpiration, stomatal conductance, and photosynthesis were significantly greater for seedlings than for mature branches. Seedlings growing in Open-Top chambers had higher gas-exchange rates than seedings growing in Branch-Exposure Chambers during November and March, but the reverse was true in July. Pigment concentrations differed significantly among mature-tree families and among seasonal sampling dates. Antioxidant enzyme activities also varied with season of sampling, although there were no indications of a significant response to pollutant exposure. 27 refs., 21 figs., 7 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: EPA
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6142728
• Report Number(s): UCRL-21001-90-2; ON: DE91008445
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
553000 -- Agriculture & Food Technology
560300* -- Chemicals Metabolism & Toxicology
60 APPLIED LIFE SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID RAIN
AGE DEPENDENCE
AIR POLLUTION
ATMOSPHERIC PRECIPITATIONS
BIOLOGICAL EFFECTS
BIOLOGICAL MODELS
CANOPIES
CHEMICAL REACTIONS
CONIFERS
DATA
DOCUMENT TYPES
ENVIRONMENTAL EXPOSURE
EXPERIMENTAL DATA
EXPOSURE CHAMBERS
GROWTH
INFORMATION
NUMERICAL DATA
OPENINGS
OZONE
PERFORMANCE TESTING
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PINES
PINOPHYTA
PLANT GROWTH
PLANTS
POLLUTION
PROGRESS REPORT
RAIN
SEASONAL VARIATIONS
SEEDLINGS
STOMATA
SYNTHESIS
TESTING
TRANSPIRATION
TREES
VARIATIONS