2680 μg m−3 SO2= 1 μl 1−1 at 25 °C and 101.3 kPa.
THE EFFECTS OF FLUCTUATING CONCENTRATIONS OF SULPHUR DIOXIDE ON THE GROWTH OF PINUS SYLVESTRIS L. AND PICEA SITCHENSIS (BONG.) CARR
Article first published online: 2 MAY 2006
Volume 97, Issue 2, pages 175–195, June 1984
How to Cite
GARSED, S. G. and RUTTER, A. J. (1984), THE EFFECTS OF FLUCTUATING CONCENTRATIONS OF SULPHUR DIOXIDE ON THE GROWTH OF PINUS SYLVESTRIS L. AND PICEA SITCHENSIS (BONG.) CARR. New Phytologist, 97: 175–195. doi: 10.1111/j.1469-8137.1984.tb04121.x
- Issue published online: 2 MAY 2006
- Article first published online: 2 MAY 2006
- (Accepted 25 January 1984)
- Pinus sylvestris;
- Picea sitchensis;
- sulphur dioxide;
Plants of Pinus sylvestris and Picea sitchensis, initially at the end of their third growing season, were grown for 2 years and 1 year, respectively, in regimes of fluctuating sulphur dioxide (SO2) concentration. The four fluctuating regimes had mean concentrations of about 100 μg m−3 and peak concentrations of either 300 to 400 μg m−3 or 750 to 900 μmg m−3,† combined with durations of high concentration which were either short (mean ∼ 5 h) and frequent, or long (mean ∼ 20 to 30 h) and infrequent. Their effects were compared with a constant concentration of about 100 μg m−3 and with clean air.
In the first year of treatment, effects on dry weight increment consisted of depressions in the root only, but marked chlorosis, necrosis and abscission of the leaves of Picea sitchensis were caused by SO2, while the leaves of Pinus sylvestris were hardly affected. By the end of the second year of treatment (Pinus sylvestris only) dry weight increase of the whole plant had been reduced by 14% in the constant concentration and in fluctuating regimes with peaks of short duration, and by 22% in regimes with peaks of long duration. All the SO2 treatments caused early fall of 3-year-old leaves during the second year of treatment of this species.
A comparison of the treatments with the characteristic regime of fluctuating concentration in those parts of Britain where the mean annual ground level concentration of SO2 is around 100 μg m−3, leads to the conclusion that the main effect of this regime is attributable to its mean, rather than its peak concentration.