模拟酸雨对广西4个树种苗木生长的影响研究

采用盆栽试验，设置4个水平(pH3.0、pH4.0、pH5.0、pH5.6)、一个对照(pH6.0),共5种处理，测定4个树种在不同pH值酸雨处理下其苗高、地径和生物量变化情况，分析不同pH值及处理方式的酸雨对广西地区速生及珍贵树种幼苗生长的影响。研究结果表明，随酸雨pH值的降低，4个树种的苗高相对生长量和地径相对生长量总体均呈下降趋势；巨尾桉9号在模拟酸雨pH3.0时，其地上生物量显著大于对照，在pH5.0时，其地下生物量、总生物量略大于对照，在pH5.6时，其根冠比最大；格木在模拟酸雨pH5.6时，其苗高相对生长量显著大于对照，根冠较对照大；降香黄檀在模拟酸雨pH5.0时，其苗高相对生长量显著高于对照，根冠比最大；在不同浓度酸雨处理下，土沉香各生长指标均显著小于对照。

Effect of Simulated Acid Rain on Growth of Four Species Seedlings in Guangxi

Based on a pot experiment, four different pH solutions (pH3.0, pH4.0, pH5.0, pH5.6) and a control (pH6.0) with five treatment methods were used to determine the changes in seedling height, ground diameter, and biomass of four tree species, and analyze the effects of acid rain with different pH values and treatment methods on the growth of fast-growing and precious tree species in Guangxi. The results showed that with the decrease of acid rain pH, the relative growth of seedling height and ground diameter of the four tree species were all decreased; the simulated acid rain in pH3.0, the above ground biomass of E.grandis×E.urophylla No.9 was significantly higher than that in the control, in pH5.0, the under ground biomass and total biomass were slightly higher than that in the control, in pH5.6, the root shoot ratio was the highest; the simulated acid rain in pH5.6, the relative growth yield and root shoot ratio of Erythrophleum fordii Oliv were significantly higher than that in the control; the simulated acid rain in pH5.0, the relative growth yield of Dalbergia odorifera T. Chen were significantly higher than that in the control, and the root shoot ratio was the highest; in different concentrations of acid rain treatment, each growth index of Aquilaria sinensis (Lour.) Gilg were significantly lower than that in the control.