盐渍化弃耕地不同恢复模式下土壤有机碳及呼吸速率的变化

Changes of Soil Organic Carbon and Soil Respiration Rate Under Different Models of Restoration of Abandoned Salinized Field

对干旱区盐渍化弃耕地不同恢复模式下土壤有机碳及呼吸速率的变化特征进行分析,结果表明:盐渍化弃耕地不同恢复模式下土壤有机碳含量为人工草地﹥补水﹥补植﹥原始弃耕地,盐渍化弃耕地通过植被恢复后逐步向碳积累的过程转变,呈现碳汇现象,其中,人工草地的土壤有机碳含量和有机碳密度分别比弃耕地高出63.45%和65.47%。土壤有机碳与土壤速效养分存在着密切的正相关关系。植被恢复后明显增加了土壤呼吸速率,不同恢复模式下土壤呼吸温度敏感系数Q10的值为人工草地(1.48)﹥补水(1.21)﹥补植(1.15)﹥原始弃耕地(1.13);土壤有机碳与土壤呼吸速率之间呈显著正相关关系,与温度敏感系数呈正相关关系。

The changes of soil organic carbon and soil respiration rate under different models of restoration of abandoned salinized field in arid region were studied. The result indicated that soil organic carbon contents under different models of restoration of abandoned salinized field were artificial grassland treatment〉appropriate irrigation treatment〉supplement planting treatment〉original abandon farmland treatment. After vegetation restoration of abandoned salinized field, soil organic carbon changed to the process of carbon accumulation progressively, present carbon sink phenomenon. The soil organic carbon contents and its density of artificial grassland were 63.45% and 65.47%, respectively, higher than that of abandoned field. The regression analysis showed that there were significantly positive correlation between soil organic carbon and soil available nutrient. Soil respiration rate was significantly enhanced after vegetation restoration, soil respiration temperature sensitivity coefficient Q10 value under different models ranked as artificial grassland treatment （1.48） 〉appropriate irrigation treatment （1.21）〉supplement planting treatment （1.15）〉original abandon farmland treatment （1.13）. There were significantly positive correlations between soil organic carbon and soil respiration, and positive correlations between soil organic carbon and temperature sensitivity coefficient, but no significant.