模拟酸雨对马尾松和杉木幼树的影响

本实验模拟酸雨pH值为6.63(对照),4.5,3.0和2.0。实验结果表明,杉木针叶汁液pH值和土壤pH值随模拟酸雨pH值下降而降低,土壤比叶汁液更容易被酸化,也更难恢复。模拟酸雨对马尾松和杉木单位叶干重净光合速率影响不显著,最高酸度的模拟酸雨由于减少光合组织而显著降低单株净光合速率。模拟酸雨显著增大了马尾松和杉木呼吸速率。模拟酸雨对茎生物量没有影响,主根和叶生物量有减少的趋势,但不显著,须根生物量有显著减少,模拟酸雨抑制植物生长的机制是增大呼吸速率使物质消耗增加和减少光合组织,导致物质生产减少。

EFFECTS OF ACID RAIN ON YOUNGLING OF PINUS MASSONIANA AND CUNNINGHAMIA LANCEOLATA

The effects of simulatad acid rain with pH values of 2.0, 3.0, 4.5 and 6.623(control) on youngling of Pinus massoniana and Cunninghamia le-nceolata were studied. The results showed that the pH of C. lanceolata leaf sap and soil decreased as the acidity of rainfall increased. In the case of low pH, the acid rain had significant effects on the photosynthetic rates per plant, but not on that per unit weight of dry leaf. The respiration rates of the two species were stimulated by the acid rain and root and leaf biomass, but not stem biomass. were also reduced dramatically during a seven months period.