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大气CO2浓度升高和N沉降以及二者之间的耦合作用对陆地森林生态系统的影响是当前国际生态学界关注的热点之一。该实验运用大型开顶箱(open-topchamber,OTC)研究:1)高CO2浓度(700μmol·mol-1)+高N沉降(100kgN·hm-2·a-1)(CN);2)高CO2浓度(700μmol·mol-1)和背景N沉降(CC);3)高N沉降(100kgN·hm-2·a-1)和背景CO2浓度(NN);4)背景CO2和背景N沉降(CK)4种处理对南亚热带主要乡土树种木荷(Schima superba)、红锥(Castanopsis hystrix)、肖蒲桃(Acmena acuminatissima)、红鳞蒲桃(Syzygium hancei)、海南红豆(Ormosia pinnata)叶片元素含量的影响。研究结果表明,大气CO2浓度升高对5种乡土树种叶片元素含量有较大的影响,除海南红豆叶片的Ca含量外,其他树种的叶片元素含量在高CO2浓度处理下都显著升高(p<0.05);而在N沉降处理下,5个树种的叶片K和Ca含量都降低。大气CO2浓度升高与N沉降处理对5种乡土树种植物叶片元素含量影响的交互作用不是很明显,仅仅木荷和红鳞蒲桃的叶片Ca和Mn以及海南红豆的叶片Mn含量在大气CO2浓度上升和N沉降交互处理下显著下降,而肖蒲桃的叶片P含量在大气CO2浓度上升和N沉降交互处理下显著上升。
Atmospheric CO2 concentration and N deposition and the coupling between the two on the impact of terrestrial forest ecosystems is one of the current international ecologists concerned about the hot spots. The experiment used large open-top chamber (OTC) studies: 1) High CO2 concentration (700μmol · mol-1) + high N sedimentation (100kgN · hm-2 · a-1) CO2 concentration (700μmol · mol-1) and background N deposition (CC); 3) high N deposition (100kgN · hm-2 · a-1) and background CO2 concentration (NN); 4) background CO2 and background N deposition CK) were used to study the effects of four treatments on the leaf elements of Schima superba, Castanopsis hystrix, Acmena acuminatissima, Syzygium hancei, Ormosia pinnata, Effect of content. The results showed that the increase of atmospheric CO2 concentration had a great effect on the leaf element contents of five native tree species except the content of Ca in Hainan red bean leaves. The leaf element contents of other tree species were significantly increased under high CO2 concentration (p <0.05). Under N deposition treatment, the contents of K and Ca in leaves of five species decreased. The interaction of elevated atmospheric CO2 concentration and N deposition on the leaf element contents of five native tree species is not obvious. Only the leaves Ca and Mn in the leaves and the Mn content in the leaves of the Hainan red bean under the atmospheric CO2 concentration While the P content decreased significantly under the interaction of uplifting and N deposition. However, the P content of X. sorbifolia increased significantly under the interaction between the increase of atmospheric CO2 concentration and N deposition.