| 草海覆被差异对土壤有机碳组分及稳定性的影响 |
| 摘要点击 879 全文点击 131 投稿时间：2024-02-21 修订日期：2024-04-30 |
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| 中文关键词 草海 覆被差异 有机碳组分 惰性有机碳指数 有机碳稳定性 |
| 英文关键词 Caohai vegetation cover organic carbon components recalcitrant organic carbon index organic carbon stability |
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| 中文摘要 |
| 覆被差异影响土壤有机碳稳定性和固碳潜力. 贵州草海是全球同纬度典型高原淡水湿地生态系统,以草海为研究对象,选取林地、耕地、草地、芦竹和滩涂这5种覆被的土壤,垂直分层采集0~20、20~40和40~60 cm的土壤样本,按照SOC的活性程度和稳定性分组,探究覆被差异对土壤有机碳组分和稳定性的影响,为草海土壤碳汇和生态保护提供基础数据. 结果表明,覆被差异导致SOC含量在垂直尺度分布的差异性（P<0.05）,水平尺度上各覆被中SOC含量与滩涂的（14.75 g·kg-1）对比,减少量分别为：19.32%（林地）、15.05%（芦竹）、12.47%（菜地）和1.58%（草地） ；碳组分中SAOC和LOC的含量分别占SOC总量的52.51%和45.00%. ω（ROC）（g·kg-1）依次为：7.89（林地）、7.47（滩涂）、6.67（芦竹）、6.36（菜地）和5.67（草地）,影响ROC的主要理化因子为N/P和TN（r≥0.72）. ROCI的变化区间为0.16~0.34,林地最大,菜地和草地相对较低,主要受N/P的影响（P<0.01）,与BD负相关（P<0.05）,覆被类型（P<0.001）和土层深度（P<0.01）均可影响土壤有机碳的稳定性,且二者交互作用于ROCI （P<0.01）. 研究表明覆被差异改变有机质的分解和积累,导致有机碳组分的差异分布,农事活动影响有机碳的稳定性和积累状态,草海不稳定碳组分SAOC和LOC含量较高,土壤固碳增汇潜力大. 建议科学地人工调控使其向稳定态转化,提升区域ROCI水平和固碳潜力. |
| 英文摘要 |
| Soil organic carbon （SOC） stability and carbon sequestration potential can be affected by vegetation cover. The Caohai in Guizhou is a typical plateau freshwater wetland ecosystem at the same latitude as other regions worldwide. The study focused on the soils from Caohai and selected five types of vegetation cover, including forest land, cultivated land, grassland, reeds, and tidal flats. Soil samples were collected vertically at depths of 0-20, 20-40, and 40-60 cm, and the activity and stability of SOC were tested to explore the impact of different vegetation covers on the composition and stability of SOC, finally providing basic data for soil carbon sequestration and ecological protection in the Caohai. The results indicated that cover variability led to differences in SOC content on the vertical distribution scale （P<0.05）. Comparing SOC content in various covers with tidal flats （14.75 g·kg-1） on a horizontal scale, reductions were observed in forests （19.32%）, reeds （15.05%）, cropland （12.47%）, and grassland （1.58%）. The proportions of stable and labile organic carbon （SAOC and LOC） accounted for 52.51% and 45.00% of the total SOC content, respectively. The ω（ROC） （g·kg-1） values were 7.89 （forests）, 7.47 （tidal flats）, 6.67 （reeds）, 6.36 （cropland）, and 5.67 （grassland）, with N/P and TN being the main physicochemical factors influencing ROC （r≥0.72）. ROCI ranged from 0.16 to 0.34, with the highest in forest land and relatively lower values in cropland and grassland, mainly affected by N/P （P<0.01）, negatively correlated with BD （P<0.05）, and influenced by cover type （P<0.001） and soil depth （P<0.01）. Both cover type and soil depth interacted significantly with ROCI （P<0.01）. The research indicated that vegetation cover variability altered organic matter decomposition and accumulation, leading to a differential distribution of organic carbon components. Agricultural activities affected the stability and accumulation status of organic carbon, contributing to the higher levels of unstable carbon components SAOC and LOC and exhibiting significant potential for soil carbon sequestration enhancement. Moreover, it is recommended to implement scientific management practices to transition towards a more stable state, thereby enhancing regional ROCI levels and carbon sequestration potential. |
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