Effects of ultraviolet-B radiation on photosynthesis of different aged needles in field-grown loblolly pine
A continuing decline in stratospheric ozone concentrations caused by atmospheric pollutants has stimulated interest in consequences of increased penetration of ultraviolet-B radiation to the surface of the earth. The authors examined the effect of supplemental UV-B (290-320 nm) on photosynthetic characteristics of different aged needles of 3-year-old, field-grown loblolly pine (Pinus taeda L.). Needles in four age classes were examined: (1) most recently fully expanded, year 3; (2) first flush, year 3; (3) final flush, year 2; and (4) oldest needles still present, year 2. Enhanced UV-B radiation caused a statistically significant decrease (6%) in the ratio of variable to maximum fluorescence (F sub v)/(F sub m) following dark adaption only in needles from the youngest age class, suggesting transient damage to photosynthesis. Exposure to enhanced UV-B radiation caused a 20% decrease in total biomass and a 4% decrease in needle length of needles in age classes 1, 2, and 4, respectivly.
- Research Organization:
- Illinois Univ., Urbana, IL (United States). Dept. of Plant Biology
- OSTI ID:
- 5048879
- Report Number(s):
- PB-94-144730/XAB; CNN: EPA-R814017020
- Resource Relation:
- Other Information: Pub. in Tree Physiology, Vol. 12, 151-162(1993)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
09 BIOMASS FUELS
CLIMATIC CHANGE
ENVIRONMENTAL IMPACTS
ULTRAVIOLET RADIATION
ELECTROMAGNETIC RADIATION
RADIATIONS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
095000 - Biomass Fuels- Environmental Aspects- (1990-)