大气二氧化碳摩尔分数升高对土壤有机碳稳定性的影响

随着工业的不断发展，全球大气二氧化碳(CO₂)呈明显增加趋势。大气CO₂的增加将会影响土壤有机碳(SOC)转化和更新，进而改变土壤碳的稳定性。研究大气CO₂升高对SOC稳定性的影响，不但是评价陆地生态系统对气候变化反馈效应的重要环节，也对实现碳元素在土壤中的有效储存，对保持土壤肥力的可持续性具有重要意义。利用现有的文献资料，综述了大气CO₂升高对SOC稳定性的影响及其稳定性指标(生物指标、化学指标、其他指标等)，外源氮和大气CO₂升高的交互作用对SOC稳定性的影响，以及SOC稳定性随时间尺度的变化趋势等。总结发现:大气CO₂升高导致活性有机碳(溶解性有机碳、颗粒性有机碳、易氧化有机碳等)比例增多，SOC稳定性降低，尤其在氮限制的环境中，SOC稳定性更差。总结近年的研究成果发现:随着高CO₂处理时间的加长，SOC稳定性降低速率逐渐减小，表明土壤本身具有一定的适应能力和自我恢复能力。最后展望了SOC稳定性变化对植物生理、生长的反馈影响。未来大气CO₂升高对SOC稳定性的影响研究，应该着力于提高农田生态系统土壤肥力可持续性及提高农作物的产量产能。图1参74

Effects of the mole fraction of elevated atmospheric CO2 on soil organic carbon stability

The fast development of the industry has been accompanied with a significant increase of the global atmospheric CO₂, which will affect the transformation and renewal of soil organic carbon (SOC), and then its stability. Therefore, an exploration of the effects of elevated atmospheric CO₂ on SOC stability is not only an important attempt to evaluate the feedback effect of terrestrial ecosystem on climate change, but also of great significance to the effective storage of element C in soil and the sustainability of soil fertility. With an overview of previous researches, this study is aimed at a summary of the effects of elevated atmospheric CO₂ on SOC stability and its stability indexes (biological index, chemical index, other index, etc.), the interaction between exogenous N and elevated atmospheric CO₂ on SOC stability as well as the variation trend of SOC stability over time. The results showed that elevated atmospheric CO₂ resulted in an increase in the proportion of labile organic carbon (readily oxidized carbon, particulate organic carbon, dissolved organic carbon, etc.), and a decrease in SOC stability, especially in nitrogen limitation environment. It was also found, with a summary of the research findings in recent decades, that there was a gradual decrease in the SOC stability reduction rate with the increase of high CO₂ treatment time, indicating that the soil itself is equipped with the capacity to adapt and recover on its own. In conclusion, given the the feedback effect of SOC stability variation on plant physiology and growth, future researches on the effects of elevated atmospheric CO₂ on SOC stability should be focused on promoting the sustainability of soil fertility in farmland ecosystem and increasing crop production and productivity. Ch, 1 fig. 74 ref.]