School of Geography, Nanjing Normal University, Nanjing, China.
Soil Science Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt.
Glob Chang Biol. 2021 Nov;27(22):5950-5962. doi: 10.1111/gcb.15851. Epub 2021 Aug 29.
Soil gross nitrogen (N) mineralization (GNM), a key microbial process in the global N cycle, is mainly controlled by climate and soil properties. This study provides for the first time a comprehensive analysis of the role of soil physicochemical properties and climate and their interactions with soil microbial biomass (MB) in controlling GNM globally. Through a meta-analysis of 970 observations from 337 published papers from various ecosystems, we found that GNM was positively correlated with MB, total carbon, total N and precipitation, and negatively correlated with bulk density (BD) and soil pH. Our multivariate analysis and structural equation modeling revealed that GNM is driven by MB and dominantly influenced by BD and precipitation. The higher total N accelerates GNM via increasing MB. The decrease in BD stimulates GNM via increasing total N and MB, whereas higher precipitation stimulates GNM via increasing total N. Moreover, the GNM varies with ecosystem type, being greater in forests and grasslands with high total carbon and MB contents and low BD and pH compared to croplands. The highest GNM was observed in tropical wet soils that receive high precipitation, which increases the supply of soil substrate (total N) to microbes. Our findings suggest that anthropogenic activities that affect soil microbial population size, BD, soil substrate availability, or soil pH may interact with changes in precipitation regime and land use to influence GNM, which may ultimately affect ecosystem productivity and N loss to the environment.
土壤总氮矿化（GNM）是全球氮循环中的一个关键微生物过程，主要受到气候和土壤特性的控制。本研究首次全面分析了土壤理化性质、气候及其与土壤微生物生物量（MB）之间的相互作用对全球 GNM 的控制作用。通过对来自不同生态系统的 337 篇已发表论文中的 970 个观测值进行荟萃分析，我们发现 GNM 与 MB、总碳、总氮和降水呈正相关，与容重（BD）和土壤 pH 呈负相关。我们的多元分析和结构方程模型表明，GBM 受 MB 驱动，并主要受 BD 和降水的影响。较高的总氮通过增加 MB 来加速 GNM。BD 的降低通过增加总氮和 MB 来刺激 GNM，而较高的降水则通过增加总氮来刺激 GNM。此外，GNM 随生态系统类型而变化，与农田相比，高总碳和 MB 含量、低 BD 和 pH 的森林和草原中的 GNM 较大。在接收高降水的热带湿地中观察到最高的 GNM，这增加了土壤基质（总氮）向微生物的供应。我们的研究结果表明，影响土壤微生物种群大小、BD、土壤基质可用性或土壤 pH 的人为活动可能与降水格局和土地利用的变化相互作用，从而影响 GNM，最终可能影响生态系统生产力和氮向环境的损失。
