An outdoor experiment was set up to investigate the effects of used lubricating oil （5 L/m^2） on Aegiceras corniculatum Blanco. and Avicennia marina （Forsk） Vierh., two salt-excreting mangroves. A. marina was more...An outdoor experiment was set up to investigate the effects of used lubricating oil （5 L/m^2） on Aegiceras corniculatum Blanco. and Avicennia marina （Forsk） Vierh., two salt-excreting mangroves. A. marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling. When treated with canopy-oiling, half of A. corniculatum plants survived for the whole treatment time （90 d）; but, for A. marina, high mortality （83%） resulted from canopy-oiling within 3 weeks and no plants survived for 80 d. Base-oiling had no lethal effects on A. corniculatum plants even at the termination of this experiment, but 83% of A. marina plants died 80 d after treatment. Forty days after canopyoiling, 93% ofA. corniculatum leaves fell and no live leaves remained on A. marina plants. By the end of the experiment, base-oiling treatment resulted in about 45% ofA. corniculatum leaves falling, while all A. mar/na leaves and buds were burned to die. Lubricating oil resulted in physiological damage to A. corniculatum leaves, including decreases in chlorophyll and carotenoid contents, nitrate reductase, peroxidase and superoxide dismutase activities, and increases in malonaldehyde contents. For both species, oil pollution significantly reduced leaf, root, and total biomass, but did not significantly affect stem biomass. Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.展开更多
基金Project supported by the Program for New Century Excellent Talents in University(NCET)Environment and Conservation Fund of the HKSAR(No.9210007)
文摘An outdoor experiment was set up to investigate the effects of used lubricating oil （5 L/m^2） on Aegiceras corniculatum Blanco. and Avicennia marina （Forsk） Vierh., two salt-excreting mangroves. A. marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling. When treated with canopy-oiling, half of A. corniculatum plants survived for the whole treatment time （90 d）; but, for A. marina, high mortality （83%） resulted from canopy-oiling within 3 weeks and no plants survived for 80 d. Base-oiling had no lethal effects on A. corniculatum plants even at the termination of this experiment, but 83% of A. marina plants died 80 d after treatment. Forty days after canopyoiling, 93% ofA. corniculatum leaves fell and no live leaves remained on A. marina plants. By the end of the experiment, base-oiling treatment resulted in about 45% ofA. corniculatum leaves falling, while all A. mar/na leaves and buds were burned to die. Lubricating oil resulted in physiological damage to A. corniculatum leaves, including decreases in chlorophyll and carotenoid contents, nitrate reductase, peroxidase and superoxide dismutase activities, and increases in malonaldehyde contents. For both species, oil pollution significantly reduced leaf, root, and total biomass, but did not significantly affect stem biomass. Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.
