Exploring the responses of greenhouse gas (GHG) emissions to land use conversion or reversion is significant for taking effective land use measures to alleviate global warming. A global meta-analysis was conducted to analyze the responses of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) emissions to land use conversion or reversion, and determine their temporal evolution, driving factors, and potential mechanisms. Our results showed that CH₄ and N₂O responded positively to land use conversion while CO₂ responded negatively to the changes from natural herb and secondary forest to plantation. By comparison, CH₄ responded negatively to land use reversion and N₂O also showed negative response to the reversion from agricultural land to forest. The conversion of land use weakened the function of natural forest and grassland as CH₄ sink and the artificial nitrogen (N) addition for plantation increased N source for N₂O release from soil, while the reversion of land use could alleviate them to some degree. Besides, soil carbon would impact CO₂ emission for a long time after land use conversion, and secondary forest reached the CH₄ uptake level similar to that of primary forest after over 40 years. N₂O responses had negative relationships with time interval under the conversions from forest to plantation, secondary forest, and pasture. In addition, meta-regression indicated that CH₄ had correlations with several environmental variables, and carbon–nitrogen ratio had contrary relationships with N₂O emission responses to land use conversion and reversion. And the importance of driving factors displayed that CO₂, CH₄, and N₂O response to land use conversion and reversion was easily affected by NH₄⁺ and soil moisture, mean annual temperature and NO₃⁻, total nitrogen and mean annual temperature, respectively. This study would provide enlightenments for scientific land management and reduction of GHG emissions.

中文翻译：

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土壤温室气体排放对土地利用转换和恢复的响应——一项全球荟萃分析

探索温室气体（GHG）排放对土地利用转变或回归的响应对于采取有效的土地利用措施缓解全球变暖具有重要意义。进行了一项全球荟萃分析，分析了二氧化碳（CO ₂）、甲烷（CH ₄）和一氧化二氮（N ₂ O）排放对土地利用转换或恢复的响应，并确定了它们的时间演变、驱动因素、和潜在的机制。我们的研究结果表明，CH ₄和N ₂ O 对土地利用转换呈正响应，而CO ₂对天然草本和次生林向人工林的变化呈负响应。相比之下，CH ₄对土地利用归还反应消极，N ₂ O对农用地归还森林也表现出消极反应。土地利用转换削弱了天然林和草地作为CH ₄汇的功能，人工人工加氮增加了N ₂ O从土壤中释放的N源，而土地利用转换可以在一定程度上缓解这种情况。 . 此外，土地利用转变后土壤碳对CO ₂排放的影响将长期存在，次生林40多年后达到与原始林相近的CH _{4吸收水平。}氮₂在森林向人工林、次生林和牧场的转变下，O响应与时间间隔呈负相关。此外，元回归表明CH ₄与多个环境变量存在相关性，碳氮比与N ₂ O排放对土地利用转换和恢复的响应呈相反关系。驱动因子的重要性表明CO ₂、CH ₄和N ₂ O对土地利用转换和恢复的响应易受NH ₄ ⁺和土壤湿度、年平均气温和NO ₃ ^{-的影响。}，总氮和年平均温度，分别。本研究将为科学土地管理和减少温室气体排放提供启示。