中文摘要：

氮沉降增加作为全球变化的重要现象之一,已经并将继续对植物叶片生态化学计量特征产生影响。以亚热带粗放经营的毛竹林为研究对象,研究了模拟氮沉降对毛竹叶片生态化学计量特征的影响。实验设计4种处理水平：低氮（L,30 kg·ha–1·a–1）、中氮（M,60 kg·ha–1·a–1）、高氮（H,90 kg·ha–1·a–1）和对照（CK,0 kg·ha–1·a–1）,处理时间1年。结果表明：模拟氮沉降处理显著提高了毛竹叶片的C、N、P含量（P〈0.05）,而且对C、P含量的增加作用随氮沉降强度而增强。同一模拟氮沉降强度处理下,3龄毛竹和1龄毛竹的叶片C、N、P含量没有表现出明显的规律性变化。毛竹叶片C︰N︰P化学计量比在各处理间处于相对稳定状态。3龄生立竹叶片的C含量与N含量存在极显著正相关关系。氮沉降水平及其与竹龄的交互作用对毛竹叶片的C、N、P含量和C︰N、C︰P、N︰P均有显著的影响,而立竹年龄只显著影响到了竹叶的C含量、C︰N、N︰P比值。在1年的模拟氮沉降后,实验区域粗放经营毛竹林的生长仍然受到N素的限制,表明适度的氮沉降可以促进该区域粗放经营毛竹林的生长,积累更多的生物量碳。

英文摘要：

As one of the important phenomenon of global change, nitrogen （N） deposition would influence the ecological stoichiometry of plant. In this study, an experiment of 12 months on the effects of N deposition on ecological stoichiometry of leaves of Moso bamboo under extensive management in subtropical China was conducted. The simulated N deposition method was used with three treatments of 30 kg.ha-1·a-1 （L）, 60 kg·ha-1.a 1 （M）, 90 kg-ha-1·a-1 （H）, and the control. The results showed that simulated N deposition significantly increased contents of C, N and P of leaves （P〈0.05）, and these effects on C and P contents became stronger generally with N deposition level. The contents of C, N and P of leaves did not show regular changes between Moso bamboo of different age under the same N deposition level. The C ： N ： P ratios of leaves showed relative stability among the different N deposition treatments. There was significantly positive correlation between C content and N content of leaves of 3-year-old Moso bamboo. The N deposition level alone and combined with Moso bamboo age had significant effects on the contents of C, N and P and ratios of C ： N, C ： P and N ： P, while Moso bamboo age alone only significantly impacted C content and C ： N ratio. Our findings indicate that the productivity of Moso bamboo forest under extensive management was still limited by N element, and the increasing N deposition would facilitate the productivity of Moso bamboo, which would contribute to more biomass carbon accumulation.