Susceptibility of European Pinus sylvestris L. populations to S02, NO 29 S02 +N02 and HF under laboratory and field conditions

Abstract

Under controlled laboratory conditions, 1-3 year-old Pinus sylvestris seedlings were exposed to SO<sub>2</sub> (0.75 mm<sup>3</sup> dm<sup>-3</sup> x 5 days, 6h daily), NO2, (0.5 mm<sup>3</sup> dm<sup>-3</sup> x 66 days, 6h daily), SO<sub>2</sub> +NO<sub>2</sub> (0.25 mm<sup>3</sup> dm<sup>-3</sup>+0.5 mm<sup>3</sup> dm<sup>-3</sup> x 19 days, 6h daily) and HF (0.25 mm<sup>3</sup> dm<sup>-3</sup> x 4 days, 6h daily). Seedlings of the same provenances had also been outplanted near two types of emission sources which pollute the environment with SO<sub>2</sub> and fluorides, and with SO<sub>2</sub> and heavy metals. Nitrogen dioxide did not cause visible symptoms of injury to plants. Exposition of plants to the action of other pollutants differentiated the studied populations in respect to the size of needle necroses. In general, northern (Sweden, USSR) and southern (Turkey, Yugoslavia) populations demonstrated lower sensitivity than pines from the more central parts of the species' range in Europe. A statistically significant correlation was shown between the injuries to seedlings observed in the field and under laboratory conditions.