The effects of nitrogen enrichment on soil CO2 fluxes depending on temperature and soil properties
The effects of nitrogen enrichment on soil CO2 fluxes depending on temperature and soil properties
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DOI：
10.1111/geb.12430
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发表时间：
2016-04
影响因子：
6.4
通讯作者：
Yangquanwei Zhong;Weiming Yan;Z. Shangguan
中科院分区：
文献类型：
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作者：
Yangquanwei Zhong;Weiming Yan;Z. Shangguan
目的 人为氮（N）的持续增加可能对土壤碳（C）通量产生重大影响；因此，了解氮富集下土壤碳通量的动态非常重要。我们的主要目标是解决迄今为止提出的相互矛盾的结果，并扩大我们对土壤呼吸（Rs）对氮富集的响应的了解，这可能受到土壤理化性质和环境因素的影响。方法我们收集了一个用于荟萃分析的大型数据集，包括来自 163 个地点的 154 篇已发表论文的 563 个年度和季节性 Rs 数据集，其中 N 富集，涵盖了全球七种类型的生物群落。结果 (1) 氮富集与全球 Rs 没有显着相关，但我们发现森林中存在负相关关系，而其他生物群落中存在正相关关系。 (2) Rs与森林和农田的氮水平呈负相关，与荒漠的氮水平呈正相关；异养呼吸与全球氮水平呈负相关，其反应与孵化环境相关。 (3) Rs对N富集的响应还与年平均气温和土壤性质相关，15℃是Rs增加和减少之间切换的阈值。 (4) 全球陆地总碳通量估计为 97.01 Pg Cyear−1，ha−1year−1 1 kg 氮富集引起的平均流出量为 1.33 kg C ha−1year−1。主要结论 应针对每个生物群落单独预测 Rs 对未来氮富集的响应。在氮富集下，Rs 变化与温度和土壤性质之间的关联使得土壤碳通量在未来温度和氮沉降增加的背景下成为更加复杂的挑战。
Aim The continuous increase in anthropogenic nitrogen (N) may have a substantial impact on soil carbon (C) fluxes; thus, understanding the dynamics of soil C fluxes under N enrichment is important. Our main goal was to resolve the conflicting results presented to date and to expand our knowledge about the response of soil respiration (Rs) to N enrichment, which may be affected by the physico-chemical properties of soil and environmental factors. Methods We assembled a large dataset for meta-analysis, including 563 datasets on annual and seasonal Rs with N enrichment from 154 published papers at 163 sites, covering seven types of biomes world-wide. Results (1) N enrichment was not significantly related to global Rs but we found a negative relationship in forests and a positive one in other biomes. (2) Rs showed a negative correlation with the N levels in forests and croplands and a positive correlation with the N levels in deserts; heterotrophic respiration exhibited negative correlations with N levels globally, and its response was correlated with the incubation environment. (3) The response of Rs to N enrichment was also correlated with mean annual temperature and soil properties, with 15 °C being the threshold for switching between increasing and decreasing Rs. (4) The estimated total C flux for global terrestrial lands was 97.01 Pg C year−1, and 1 kg of N enrichment at ha−1 year−1 induced an average efflux of 1.33 kg C ha−1 year−1. Main conclusions The response of Rs to future N enrichment should be predicted separately for each biome. The association between changes in Rs and temperature and soil properties under N enrichment makes soil C flux a more complex challenge in the context of future increases in temperature and N deposition.