Simulated effects of nitrogen saturation the global carbon budget using the IBIS model

Xuehe Lu; Hong Jiang; Jinxun Liu; Xiuying Zhang; Jiaxin Jin; Qiuan Zhu; Zhen Zhang; Changhui Peng

doi:10.1038/srep39173

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Simulated effects of nitrogen saturation the global carbon budget using the IBIS model

Xuehe Lu·Hong Jiang·Jinxun Liu·Xiuying Zhang·Jiaxin Jin·Qiuan Zhu·Zhen Zhang·Changhui Peng

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Abstract

Over the past 100 years, human activity has greatly changed the rate of atmospheric N (nitrogen) deposition in terrestrial ecosystems, resulting in N saturation in some regions of the world. The contribution of N saturation to the global carbon budget remains uncertain due to the complicated nature of C-N (carbon-nitrogen) interactions and diverse geography. Although N deposition is included in most terrestrial ecosystem models, the effect of N saturation is frequently overlooked. In this study, the IBIS (Integrated BIosphere Simulator) was used to simulate the global-scale effects of N saturation during the period 1961–2009. The results of this model indicate that N saturation reduced global NPP (Net Primary Productivity) and NEP (Net Ecosystem Productivity) by 0.26 and 0.03 Pg C yr −1 , respectively. The negative effects of N saturation on carbon sequestration occurred primarily in temperate forests and grasslands. In response to elevated CO 2 levels, global N turnover slowed due to increased biomass growth, resulting in a decline in soil mineral N. These changes in N cycling reduced the impact of N saturation on the global carbon budget. However, elevated N deposition in certain regions may further alter N saturation and C-N coupling.

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Xuehe Lu, Hong Jiang, Jinxun Liu, Xiuying Zhang, Jiaxin Jin, Qiuan Zhu, Zhen Zhang, Changhui Peng. 2016-12-14. Simulated effects of nitrogen saturation the global carbon budget using the IBIS model. https://doi.org/10.1038/srep39173

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