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为了探究城市典型绿化树种夏季光合特性及其固碳释氧能力,选取了上海地区17个常用城市绿化树种,使用LI-6400光合仪测定植物光合特性,分析光合作用主要影响因子的相关性,并对常用绿化树种的日固碳释氧能力进行定量计算和聚类分析。结果表明:(1)在17个树种中,无患子、香樟、冬青和白玉兰日均净光合速率较高,广玉兰、蚊母树和深山含笑较低;所有树种净光合速率日变化都表现为早晚低、午间前后高的特点;除冬青、深山含笑外,其他树种净光合速率日变化为双峰曲线,存在较明显的“光合午休”现象;(2)除白玉兰外,其他树种净光合速率与蒸腾速率、气孔导度、太阳辐射和气温呈正相关;(3)冬青、香樟单位土地面积日固碳释氧能力较高,深山含笑、蚊母树、栾树及广玉兰的单位土地面积日固碳释氧能力较低。在城市绿化树种选择过程中,当考虑植物固碳释氧能力时,应选择无患子、冬青、香樟、白玉兰、鹅掌楸、重阳木、三角枫和银杏等固碳释氧能力较强的树种,而适量配置深山含笑、蚊母树、栾树和广玉兰等固碳释氧能力较弱的树种。
In order to explore summer photosynthetic characteristics and carbon sequestration and oxygen release ability of typical greening tree species in Shanghai, 17 commonly used urban greening species in Shanghai were selected. The photosynthetic characteristics of plants were determined by LI-6400 photosynthesis system, and the correlations of the main influencing factors of photosynthesis were analyzed. The daily carbon fixation and oxygen release capacity of common tree species were quantitatively calculated and clustered. The results showed that: (1) In 17 tree species, the average daily net photosynthetic rate of Sapindaceae, Campanulaceae, Holly and Magnolia were higher than those of Magnolia grandiflora, Mosquito trees and the deep mountains; the diurnal variation of net photosynthetic rate (2) In addition to Magnolia grandiflora, the net photosynthetic rate of other tree species changed to a bimodal curve with the exception of holly, The net photosynthetic rate of other tree species was positively correlated with transpiration rate, stomatal conductance, solar radiation and air temperature. (3) The net carbon fixation and oxygen release per unit area of Hollyhock and Camphor was higher, Per unit area of ?? land carbon fixation oxygen release lower. In the selection of urban greening tree species, when taking into account the carbon sequestration and oxygen release capacity of plants, the ability of carbon sequestration and oxygen release such as Sapindaceae, Hollyhock, Camphora, Magnoliaceae, Liriodendron, Chongyangmu, Strong species, but the amount of allocation of mountain smiling, mosquito mother tree, Koelreuteria Magnolia and other carbon fixation weak oxygen species.