| Popis: |
Under controlled laboratory conditions, 1-3 year-old Pinus sylvestris seedlings were exposed to SO2 (0.75 mm3 dm-3 x 5 days, 6h daily), NO2, (0.5 mm3 dm-3 x 66 days, 6h daily), SO2 +NO2 (0.25 mm3 dm-3+0.5 mm3 dm-3 x 19 days, 6h daily) and HF (0.25 mm3 dm-3 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 SO2 and fluorides, and with SO2 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. |
