生态环境学报2024，Vol.33Issue(11)：1686-1695,10.DOI:10.16258/j.cnki.1674-5906.2024.11.003
凋落物C/N对土壤有机碳矿化的影响
The Influence of Litter C/N Ratios on Soil Organic Carbon Mineralization
摘要
Abstract
Litter input influences the soil organic carbon(SOC)mineralization process,with its effect primarily governed by litter C/N,soil fertility,and temperature conditions.However,the combined impact of these three factors remains unclear.This study used low-fertility soil(LF)and high-fertility soil(HF),adding seven different C/N ratio litters and setting incubation temperatures of 23℃and 33℃,with constant temperature and no light exposure.CO2 emissions were dynamically monitored to investigate how SOC mineralization responds to the three factors.Results showed that litter addition significantly increased peak CO2 emission rates,and litter with a C/N ratio less than 30 had a more pronounced effect on peak CO2 emission rates compared to litter with a C/N ratio greater than 30.The peak CO2 emission rate was also affected by soil fertility and incubation temperature,with the highest peak CO2 emission rate observed under the HF-33℃condition.Litter with a C/N ratio below 30 significantly increased cumulative CO2 emissions,with maximum increases of 407%,304%,345%and 160%under LF-23℃,LF-33℃,HF-23℃and HF-33℃conditions,respectively.Correlation analysis showed a negative relationship between SOC mineralization rate and litter C/N ratio,suggesting that lower-quality litter inhibits SOC mineralization.Under LF-23℃,LF-33℃,HF-23℃and HF-33℃conditions,compared to litter with the lowest C/N ratio(CN1),adding litter with the highest C/N ratio(CN7)reduced SOC mineralization rates by 3.53,3.04,1.71 and 2.06 times,respectively.Soil fertility influenced SOC mineralization,with the SOC mineralization rate in HF being 1.29 to 2.66 times higher than in LF.The effect of incubation temperature on SOC mineralization showed significant differences in HF,and compared to the CK,litter addition in HF significantly reduced the temperature sensitivity(Q10)of SOC mineralization.Using the PLS-PM model,the study concluded that SOC mineralization results from the combined effects of litter C/N,soil fertility,and incubation temperature.Specifically,the litter C/N ratio exerted a significant negative effect on SOC mineralization,while soil fertility had a major positive effect,and the effect of temperature was relatively minor.The results contribute to a better understanding of how the input of exogenous organic matter with different C/N ratios affects SOC mineralization under various soil fertility and temperature conditions,as well as the underlying combined effects.关键词
凋落物输入/凋落物碳氮比/有机碳矿化/CO2释放速率/室内培养/温度敏感性Key words
litter input/litter C/N ratio/organic carbon mineralization/CO2 release rate/indoor cultivation/temperature sensitivity分类
农业科技引用本文复制引用
李天,苗淑杰,余洁,赵玉蝶,乔云发..凋落物C/N对土壤有机碳矿化的影响[J].生态环境学报,2024,33(11):1686-1695,10.基金项目
国家自然科学基金项目(42177279 （）
42130506) （）
江苏省碳达峰碳中和科技创新专项(BE2022425) （BE2022425）
