CAN Canopy Addition of Nitrogen Better Illustrate the Effect of Atmospheric Nitrogen Deposition on Forest Ecosystem?

作者：Wei Zhang, Weijun Shen, Shidan Zhu, Shiqiang Wan, Yiqi Luo, Junhua Yan, Keya Wang, Lei Liu, Huitang Dai, Peixue Li, Keyuan Dai, Weixin Zhang, Zhanfeng Liu, Faming Wang, Yuanwen Kuang, Zhian Li, Yongbiao Lin, Xingquan Rao, Jiong Li, Bi Zou, Xian Cai, Jiangming Mo, Ping Zhao, Qing Ye, Jian‐Guo Huang, Shenglei Fu · 发表于：Scientific Reports · 年份：2015 · DOI：10.1038/srep11245 · 被引用次数：135 · 研究领域：Soil Carbon and Nitrogen Dynamics、Plant responses to elevated CO2、Plant Water Relations and Carbon Dynamics

Increasing atmospheric nitrogen (N) deposition could profoundly impact community structure and ecosystem functions in forests. However, conventional experiments with understory addition of N (UAN) largely neglect canopy-associated biota and processes and therefore may not realistically simulate atmospheric N deposition to generate reliable impacts on forest ecosystems. Here we, for the first time, designed a novel experiment with canopy addition of N (CAN) vs. UAN and reviewed the merits and pitfalls of the two approaches. The following hypotheses will be tested: i) UAN overestimates the N addition effects on understory and soil processes but underestimates those on canopy-associated biota and processes, ii) with low-level N addition, CAN favors canopy tree species and canopy-dwelling biota and promotes the detritus food web, and iii) with high-level N addition, CAN suppresses canopy tree species and other biota and favors rhizosphere food web. As a long-term comprehensive program, this experiment will provide opportunities for multidisciplinary collaborations, including biogeochemistry, microbiology, zoology, and plant science to examine forest ecosystem responses to atmospheric N deposition.