| O3浓度升高对南方城市绿化树种氮素的影响 |
| 摘要点击 2084 全文点击 996 投稿时间：2014-02-22 修订日期：2014-04-03 |
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| 中文关键词 绿化树种 氮素分配 氮素吸收 开顶式气室 臭氧 |
| 英文关键词 greening tree species N distribution N uptake open top chamber ozone |
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| 中文摘要 |
| 近地层臭氧（O3）浓度升高会降低树木的光合速率，抑制Rubisco酶的活性，势必会间接影响树木N素的吸收与分配. 本研究利用开顶式气室研究过滤大气（CF，<20 nL ·L-1）与O3浓度升高（E-O3，约150 nL ·L-1）对10种南方城市常用绿化树种幼苗N素吸收和分配的影响. 结果表明，与CF相比，E-O3使枫香叶生物量和马褂木茎生物量分别显著降低了20.9%和21.4%，使枫香和马褂木的根生物量显著降低了24.2%和32.5%. O3对被测树种茎中N素含量影响显著，而对叶和根中N素含量无显著影响. O3对被测树种整株树N素吸收总量（Ntu）、叶片N素吸收量及根的N素吸收量存在显著影响，而对茎N素吸收量无显著影响. 与CF相比，E-O3使马褂木与木荷的Ntu分别显著降低了28.4%与22.7%，而使舟山新木姜子Ntu显著增加了15.5%. O3浓度升高对各树种N素吸收量在各器官中的分配无显著影响. |
| 英文摘要 |
| Numerous studies have indicated that rising ozone (O3) in the troposphere significantly decreased the photosynthesis and the activity of Rubisco enzyme. So it can be inferred that the N uptake and distribution within the plants could be affected by elevated O3. In this study, ten greening woody species, widely distributed in subtropical China, were exposed to charcoal-filtered air (CF, less than 20 nL ·L-1) and elevated O3 (E-O3, mean concentration of 150 nL ·L-1) in open top chambers. The results showed that E-O3 significantly reduced the leaves biomass in Liquidamba formosana by 20.9%, the stem biomass in Liriodendron chinense by 21.4%, the root biomass in L. formosana and L. chinense by 24.2% and 32.5%, respectively. E-O3 significantly affected the N concentration in the stem but not those in leaves and root. The N uptakes in the whole tree (Ntu), the leaves and the root were significantly affected by E-O3. Compared to CF, E-O3 significantly reduced the Ntu in L. chinense by 28.4% and Schima superba by 22.7% but significantly increased the Ntu in Neolitsea sericea by 15.5%. Elevated O3 concentration had no significant influence on N distribution within the plants across the selected 10 tree species. |
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