State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Nat Ecol Evol. 2018 Nov;2(11):1724-1734. doi: 10.1038/s41559-018-0677-1. Epub 2018 Sep 24.
The nitrogen (N) cycle in terrestrial ecosystems is strongly influenced by resorption before litter fall and by mineralization after litter fall. Although both resorption and mineralization make N available to plants and are influenced by climate, their linkage in a changing environment remains largely unknown. Here, our synthesis study shows that, at the global scale, increasing N-resorption efficiency negatively affects the N-mineralization rate. As temperature and precipitation increase, the increasing rates of N cycling closely correspond to a shift from the more conservative resorption pathway to the mineralization pathway. Furthermore, ecosystems with faster N-cycle rates support plant species that have higher foliar N:P ratios and microbial communities with lower fungi:bacteria ratios. Our study shows an ecosystem scale trade-off in N-acquisition pathways. We propose that incorporating the dynamic interaction between N resorption and N mineralization into Earth system models will improve the simulation of nutrient constraints on ecosystem productivity.
陆地生态系统中的氮（N）循环强烈受到凋落物前的再吸收和凋落物后的矿化作用的影响。尽管再吸收和矿化都使 N 可供植物利用，并受气候影响，但它们在变化环境中的联系在很大程度上仍然未知。在这里，我们的综合研究表明，在全球范围内，增加再吸收效率会负地影响矿化速率。随着温度和降水的增加，N 循环的增加速率与从更保守的再吸收途径向矿化途径的转变密切相关。此外，具有更快 N 循环速率的生态系统支持具有更高叶片 N:P 比的植物物种和真菌：细菌比例较低的微生物群落。我们的研究表明，N 吸收途径在生态系统尺度上存在权衡。我们提出，将 N 再吸收和 N 矿化之间的动态相互作用纳入地球系统模型，将提高对养分限制生态系统生产力的模拟。
