Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
New Phytol. 2012 Oct;196(2):472-488. doi: 10.1111/j.1469-8137.2012.04269.x. Epub 2012 Aug 24.
Ecosystem nitrous oxide (N2O) emissions respond to changes in climate and CO2 concentration as well as anthropogenic nitrogen (N) enhancements. Here, we aimed to quantify the responses of natural ecosystem N2O emissions to multiple environmental drivers using a process-based global vegetation model (DyN-LPJ). We checked that modelled annual N2O emissions from nonagricultural ecosystems could reproduce field measurements worldwide, and experimentally observed responses to step changes in environmental factors. We then simulated global N2O emissions throughout the 20th century and analysed the effects of environmental changes. The model reproduced well the global pattern of N2O emissions and the observed responses of N cycle components to changes in environmental factors. Simulated 20th century global decadal-average soil emissions were c. 8.2-9.5 Tg N yr(-1) (or 8.3-10.3 Tg N yr(-1) with N deposition). Warming and N deposition contributed 0.85±0.41 and 0.80±0.14 Tg N yr(-1), respectively, to an overall upward trend. Rising CO2 also contributed, in part, through a positive interaction with warming. The modelled temperature dependence of N2O emission (c. 1 Tg N yr(-1) K(-1)) implies a positive climate feedback which, over the lifetime of N2O (114 yr), could become as important as the climate-carbon cycle feedback caused by soil CO2 release.
生态系统一氧化二氮（N2O）排放对气候变化和二氧化碳浓度以及人为氮（N）增强的响应。在这里，我们旨在使用基于过程的全球植被模型（DyN-LPJ）量化自然生态系统 N2O 排放对多种环境驱动因素的响应。我们检查了非农业生态系统的模型化年 N2O 排放是否可以再现全球范围内的田间测量结果，并实验观察到对环境因素阶跃变化的响应。然后，我们模拟了整个 20 世纪的全球 N2O 排放，并分析了环境变化的影响。该模型很好地再现了全球 N2O 排放格局以及 N 循环组分对环境因子变化的观测响应。模拟的 20 世纪全球十年平均土壤排放量约为 8.2-9.5 Tg N yr(-1)（含 N 沉积时为 8.3-10.3 Tg N yr(-1)）。变暖和 N 沉积分别贡献了 0.85±0.41 和 0.80±0.14 Tg N yr(-1)，导致总体呈上升趋势。CO2 上升也通过与变暖的正相互作用部分做出贡献。模型化的 N2O 排放对温度的依赖性（约 1 Tg N yr(-1) K(-1)) 意味着存在正的气候反馈，在 N2O 的寿命（114 年）内，这可能与土壤 CO2 释放引起的气候-碳循环反馈一样重要。
