酸沉降胁迫对不同家系马尾松幼苗耐酸性的影响

Assessment of Acid-Tolerant Parameters of Different Pinus massoniana Families under Acid Deposition Stress

由于我国工业化、城镇化进程日益加快,环境污染不断加剧,由此引起酸雨频率及强度增加,长期酸雨侵蚀造成我国大面积土壤酸化。酸沉降影响森林的生长,主要表现：1）抑制植物养分、水分的吸收和运输;2）抑制光合作用;3）抑制呼吸作用;

The seedlings of 16 elite Masson pine （Pinus massoniana） families, with stable high-yield, including family 35, 38, 76, 78, 79, 80, 88, 89, 90, 114, 115, 116, 117, 119, 16, 147, and 151, were used to explore the effects of precipitation acidity on their acid tolerance. The physiological parameters （biomass, relative plasma membrane permeability, chlorophyll） of the families cultivated in root-boxes outdoor were measured under treatments by spraying simulated acid rain at different pH values （2.5, 3.5, 4.5 and 5.6）. The results showed that the biomass and chlorophyll content decreased with the increase of rain acidity, but the ratios of chlorophyll a/b increased with the increase of rain acidity. In addition, with the rain acidity increased, the relative plasma membrane permeability of the pine seedlings increased, suggesting that the injury of cell membrane was enhanced. These parameters varied with different P. massoniana families. Meanwhile, when rain pH decreased from 5.6 to 4.5, these parameters were slightly decline, but a significant decline was observed from pH 3.5 to 2.5, indicating that these pine families had relatively high productivity under mild acid environment at pH 4.5 to 5.6, and suggesting the tree species, Masson pine, would be suitable for being planted in mild acid soils.