阿克苏市6种园林乔木气体交换特性研究

Study on Gas Exchange Characteristics of Six Urban Tree Species in Aksu City

对阿克苏市6种园林乔木,即法国梧桐(Platanus×acerifolia)、白蜡(Fraxinus rhynchophylla)、桑树(Morus alba)、核桃(Juglans regia)、樱桃(Cerasus pseudocerasus)和苹果(Malus pumila)活体叶片气体交换特性及其与环境因子的相关性进行了研究.结果表明:6种乔木叶片净光合速率日变化呈双峰曲线,表现出光合"午休"现象,其中樱桃、桑树和法国梧桐为非气孔因子限制,而核桃、白蜡和苹果为气孔因子限制.6种乔木光合速率排序为苹果>樱桃>核桃>桑树>白蜡>法国梧桐;蒸腾速率排序苹果>樱桃>桑树>核桃>白蜡>法国梧桐;水分利用效率强度大小为:白蜡>核桃>桑树>法国梧桐>樱桃>苹果.6种乔木抗旱性能力排序为:樱桃>苹果>桑树>白蜡>核桃>法国梧桐.单因素方差分析表明:蒸腾作用与气孔导度在不同乔木之间差异极显著(P<0.01);净光合速率、水分利用效率和胞间CO2浓度不同乔木之间的差异不显著.通过进行环境因子与气体交换特性相关性研究可以得出:白蜡、樱桃、苹果、桑树和核桃的光合速率受空气相对湿度影响较大,而法国梧桐的光合速率受气温影响较大.

The leaf gas exchange of six urban tree species in Aksu, including Platanus×acerifolia, Fraxinus rhynchophylla Morus alba, Juglans regia, Cerasus pseudocerasus and Malus pumila were measured under field conditions. The results showed that diurnal variation of photosynthetic rate（Pn） of all tree species demonstrated bimodal curve, it has significant photosynthesis ＂midday depression＂ phenomenon,the main cause of the ＂midday depression＂ of Cerasus, Morus, Platanus is that they are not limited by stomata factor, while Juglans, Fraxinus and Malus are limited by stomata factor. And Pnof six tree species were ordered by Malus〉Cerasus〉Juglans〉Morus〉Fraxinus〉Platanus; Tr were ordered by Malus〉Cerasus〉Morus〉Juglans〉Fraxinus〉Platanus; Water Use Efficiencies（WUE） were ordered by Fraxinus〉Juglans〉Morus〉Platanus〉Cerasus〉Malus. Drought resistance ability of six tree species were ordered by Cerasus〉Malus〉Morus〉Fraxinus〉Juglans〉Platanus. ANOVA analysis showed that Tr, Gs of six tree species were significantly different（P〈0.01）; while, Pn、WUE and Ciwere not significantly different.Pearson correlation analysis between environmental factors and the gas exchange parameters showed that Pn rate of Fraxinus, Cerasus, Malus, Morus and Juglans were significantly influenced by RH, while, Pnof Platanus was influenced by Ta.