Relationships of cumulative transpiration and oxidant dose to foliage injury development of ponderosa and Jeffrey pines

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · Phytopath. News; (United States)

OSTI ID:6727116

Miller, P R; Quick, T C; Vincent, P L; Van Doren, R E; Thomas, M A

Observations were made biweekly of the same needles of ponderosa and Jeffrey pines having different amounts of chronic injury and located in plots along a gradient of decreasing oxidant dose in the San Bernardino mountains. Changes in the rate of foliage injury development were based on the percent of the total needle length with chlorotic mottle, intensity differences in that symptom and needle abscission. Hourly temperatures and relative humidities and biweekly predawn xylem water potential and minimum daily stomatal resistance were inputs to a model that calculated daily potential (T/sub p/) and actual (T/sub a/) transpiration. Cumulative dose was calculated from hourly oxidant measurements. A positive relationship was noted between increasing (T/sub p/) and oxidant dose on a daily basis, suggesting a dose response model including transpiration rate and seasonal pattern as an important modifier of injury development. The ratio T/sub a//T/sub p/, an index of the seasonal moisture regime used to modify dose, did not show any influence on injury over the narrow range experienced in 1976. Linear equations describing within-season injury showed differences that were related to the pre-existing amount of chronic injury, i.e., number of annual needle whorls retained. Symptom intensity decreased overwinter.

• Research Organization: Pacific Southwest Forest and Range Experiment Station, Riverside, CA (USA)
• OSTI ID: 6727116
• Journal Information: Phytopath. News; (United States), Journal Name: Phytopath. News; (United States) Vol. 2:9; ISSN PHYNB
• 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.
CHLOROSIS
CHRONIC EXPOSURE
CONIFERS
DAILY VARIATIONS
DOSE-RESPONSE RELATIONSHIPS
ECOLOGICAL CONCENTRATION
EQUATIONS
HOURLY VARIATIONS
LEAVES
MATHEMATICAL MODELS
MOUNTAINS
PATHOLOGICAL CHANGES
PHOTOCHEMICAL OXIDANTS
PINES
PLANTS
SAN BERNARDINO MOUNTAINS
SEASONAL VARIATIONS
SYMPTOMS
TOXICITY
TRANSPIRATION
TREES
VARIATIONS