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Epicuticular waxes on the needles of Norway spruce and Scots pine in the area of the Kunda cement plant
2000
Mandre, M. | Bogdanov, V. (Estonian Agricultural Univ., Tartu (Estonia). Forest Research Inst.)
The aim of the study was to compare the amount of epicuticular waxes of Norway spruce and Scots pine needles from the area of cement production in Kunda. The amount of Norway spruce waxes decreased under air pollution influences and with ageing. The quantity of waxes of Scots pine needles showed an increasing tendency in the polluted area and in one-year-old needles compared with the current-year ones. A rapid decrease in the amount of waxes was established also in the older needles of Scots pine
Показать больше [+] Меньше [-]Chronology of needle retention in Scots pine trees growing near the Ahtme Power Plant
2000
Pensa, M. (University of Tartu, Tartu (Estonia). Inst. of Ecology)
A needle trace method was used to reveal the chronology of needle retention and growth rates on Scots pine in a stand near a power plant operating on oil shale. During the period of 1964-97, the height increment varied between 31 and 64 cm yr (-1), and the radial increment ranged from 1.06 to 3.71 mm yr (-1). The average needle density on the newly sprouted shoots of the main stem was 5.9 needles cm (-1) and the mean needle production on the same shoots was 266. The average number of needle sets along the main stem ranged from 2.2 to 3.1, the mean age of needles varied between 1.3 and 2.3 years. The short-term maximum concentrations of oil shale fly ash and SO2 ranged from 55 to 2510, and from 75 to 270 micro g m (-3), respectively. The annual average concentrations of fly ash varied between 6 and 95 micro g m (-3), and of SO2 between 2.5 and 10 micro g m (-3). Changes in neither the concentrations of fly ash nor SO2 were associated with the variation in needle retention of Scots pine. In the case of height increment, however, the correlation with the annual average concentration of oil shale fly ash was significant (r=0.83; p0.05)
Показать больше [+] Меньше [-]Air pollution impact on the content of carbohydrates in the needles of Norway spruce
2000
Mandre, M. | Kloseiko, J. (Estonian Agricultural Univ., Tartu (Estonia). Forest Research Inst.)
It was ascertained that the content of soluble sugars, starch and ratios between different forms of carbohydrates varied in the trees growing in areas affected by industrial production in Kohtla-Jaerve and Kunda. The ratio of soluble sugars to starch is a good indicator of the state of trees in industrial areas. This ratio depends on the level of air pollution. In the studied areas a strong relationship between the content of soluble sugars and N, Mg and K was observed in the needles of Norway spruce
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