中文关键词棕色石灰土温度水分¹⁴C-碳酸钙 英文关键词brown limestone soiltemperaturesoil moisture¹⁴C-labeled calcium carbonate

作者	单位	E-mail
徐学池	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125 中国科学院大学, 北京 100049 中国科学院环江喀斯特农业生态试验站, 环江 547100	xuxuechi16@mails.ucas.ac.cn
黄媛	广西药用植物园, 南宁 530000
何寻阳	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
王桂红	贵州大学农学院, 贵阳 550025
苏以荣	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125	yrsu@isa.ac.cn

中文摘要 为了探明环境因子对喀斯特土壤碳酸盐转化的影响，从而为深入理解土壤生态过程及碳循环提供理论依据.以典型喀斯特地区棕色石灰土和地带性红壤（对照）为研究对象，采用添加¹⁴C-CaCO₃室内培养100 d的方法，研究3种温度（15、25、35℃）和水分（30%、65%和100% WHC）条件下土壤无机碳释放特征.结果表明，不同水分和温度条件下，棕色石灰土无机碳释放速率最大值和100d累积最大释放量为0.7~16.8 mg·（kg·d）^-1和5.9~29.4 mg·kg^-1，红壤为39.7~103.3 mg·（kg·d）^-1和83.3~135.1 mg·kg^-1；干旱条件下（30% WHC）两种土壤无机碳累积释放量最大，随温度升高而增加，而且在65% WHC和100% WHC条件下，升温仍促进土壤无机碳释放；棕色石灰土无机碳释放的温度敏感性大于红壤，受土壤水分影响显著.添加碳酸钙后土壤pH和MBC含量均显著增加，两种土壤差异显著.方差分解结果表明，温度可解释无机碳释放7.6%的变异，水分解释变异的2.0%.因此在全球气候变化和极端降水事件增加的背景下，研究西南喀斯特土壤碳循环及其动态变化规律时，应充分考虑土壤水分和温度对土壤无机碳释放的影响. 英文摘要 In order to understand the influence of environmental factors on the carbonate conversion of the Karst soil, typical brown limestone and red soil samples were collected from the Karst ecosystem, and a 100-day incubation experiment was conducted. The characteristics of inorganic carbon release from the soil under three temperature gradients (15, 25, and 35℃) and water contents (30%, 65%, and 100% WHC) were studied by adding ¹⁴C-CaCO₃ for 100 d. The results showed that under the different soil moisture and temperature conditions, the maximum rate and the cumulative amount of inorganic carbon release from the soil over 100 days varied between 0.7-16.8 mg·(kg·d)^-1and 5.9-29.4 mg·kg^-1, respectively, in the brown limestone soil, and varied between 39.7-103.3 mg·(kg·d)^-1 and 83.3-135.1 mg·kg^-1, respectively in the red soil. Under drought conditions (30% WHC), the cumulative amount of inorganic carbon release was the highest for the two soils and increased with increasing temperature. At 65% WHC and 100% WHC, increasing temperature can still promote inorganic carbon release from the soil. The temperature sensitivity of the soil inorganic carbon release in the brown limestone soil is greater than that of the red soil, which is significantly affected by soil moisture. The soil pH and MBC content were remarkably increased after adding CaCO₃, and the difference between the two soils was significant. The variance partition showed that temperature and soil moisture can explain 7.6% and 2.0% of the soil inorganic carbon release variability, respectively. In conclusion, warming and drought aggravate inorganic carbon release from brown limestone soil in the southwestern Karst region. Therefore, in the context of global warming and more frequent extreme precipitation events, the effects of soil moisture and temperature on inorganic carbon conversion in soil should be fully considered when studying the soil carbon cycle and its dynamic changes in southwestern Karst. This research can provide a scientific basis for further understanding the influence of climate change on the global carbon cycle.

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