RELATIVE PERFORMANCE OF CONIFER POPULATIONS IN VARIOUS TESTS FOR SENSTIVITY TO SO₂, AND THE IMPLICATIONS FOR SELECTING TREES FOR PLANTING IN POLLUTED AREAS

Abstract

SUMMARYThe sensitivity of five Pinus and three Picea populations to SOg was compared in various types of fumigation experiment (i) > 9 months at 200 /ig m-^, (ii) 6 h at 8000 /ig m-^, (iii) 9 weeks at 800 fig m », (iv) 12 h (overnight) at 17 000 /xg vcT^ preceded by either 42 days or 6 h at 800 fig m ^ To complement the fumigation experiments the growth of four of the populations was compared at a polluted (London) and a control site (Silwood Park).There was no relationship between the relative sensitivity of the populations to 200 /ig nC( measured as relative growth rate) and the degree of acute injury at 8000 fig mT^. In general the populations oi Picea were more sensitive to low concentrations of SOg but more resistant to acute injury than those of Pinus. At 800 fig m~^ the initial symptoms were of acute injury, but later whole needles died and were shed. Populations prone to the initial injury were not necessarily sensitive to the later type, and vice versa.Leaf fall was accelerated and dry wt gain depressed at the polluted site compared with the control and these effects were much greater in Picea than in Pinus populations.It is concluded that the order of sensitivity obtained in screening experiments depends largely on the conditions used, and that short-term experiments with high concentrations of SOg cannot be used to predict the responses of conifers to low concentrations of SOg in the field.

The occurrence of SO2‐related foliar symptoms on Scots pine (Pinus sylvestris L.) in an open‐air forest fumigation experiment

“…Concentrations of 1000 ppb for four hours during early summer might be expected to lead to injury, due to the great difference between this concentration and the 7 ppb threshold inferred from field observations. However, Garsed & Rutter (1982) found no relationship between sensitivity to chronic and acute SO.2 fumigations for Scots pine or other conifers. The National Research Council of Canada (1939) found no visible effects on yellow pine Pinus ponderosa with exposures of 1000 ppb for up to 220 h. They found some evidence of a window of greater sensitivity; in one experiment run at the end of March (apparently on newly burst needles), 147 h exposure to 750 ppb SO2 led to extensive foliar necrosis.…”

“…The National Research Council of Canada (1939) found no visible effects on yellow pine Pinus ponderosa with exposures of 1000 ppb for up to 220 h. They found some evidence of a window of greater sensitivity; in one experiment run at the end of March (apparently on newly burst needles), 147 h exposure to 750 ppb SO2 led to extensive foliar necrosis. Garsed & Rutter (1982) found acute injury on Scots pines fumigated with 2800 ppb SO2 for 6 h or 280 ppb for 9 wk, but not at 70 ppb for 9 months. A factor considered crucial by The National Research Council of Canada (1939) was the humidity during fumigations, with levels below 60% being too low for significant pollutant absorption.…”

The Effect of Coal Utilization Emissions on Natural and Man-managed Terrestrial and Freshwater Ecosystems

“…Garsed, Mueller and Rutter (1982) found no effect of 100 pg m" 3 S0 2 on Pinus sylvestris over one year, but on continuing the fumigation for a second year, significant growth reductions took place. This latent effect has recently been confirmed in the field by Garsed and Rutter (1982b), who exposed five conifer species outdoors for two years in the centre of London and at an unpolluted rural site: over the first year all species grew better in London, reflecting higher temperatures in an urban area, but by the end of the second year growth was significantly reduced compared with the rural site. The mean S0 2 concentration in central London throughout the experiment was only 79/igm -3 , although the effect of other pollutants cannot be discounted.…”

Interactions of calcium sulfite with soils and plants

“…Olszyk et al (1986) reported that long-term exposure of Yecorra Rojo wheat to air containing 0.15 pL L -l SO2 decreased yields, and that short-term exposure to approximately 1 pL L -t caused acute toxicity effects. Garsed and Rutter (1982) found that the presence of 3 #L L -~ SO2 for 6 hours caused acute damage to several pine (Pinus) species.…”