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土壤呼吸是土壤有机C矿化分解,释放无机养分的重要生物化学过程。本研究通过实验室培养的方法,分析了沙坡头地区人工固沙区不同固沙年限土壤碳矿化潜力的变化。经过103d的室内培养,土壤CO2-C的释放量表现为55龄>47龄>30龄>24龄>21龄>流动沙丘,在垂直方向上表现为0～5cm>5～10cm>10～20cm。而流沙区土壤碳矿化潜力为10～20cm土层最高。不同固沙年限土壤碳矿化潜力、全氮、有机碳、电导率有明显的差异,均表现为随植被恢复年限的延长而增加,随深度的增加而递减。相关性分析表明,土壤碳矿化潜力与土壤有机碳、总氮、C/N、pH、电导率、温度、土壤水分含量呈极显著相关,土壤各环境因子之间亦呈极显著相关。土壤养分含量随着恢复时间的延长而得到明显的改善,土壤碳矿化潜力与土壤养分状况改善程度一致。人工固沙植被的建立促进了土壤微生物活性,通过潜在的土壤呼吸得到表征。植被恢复和凋落物积累使土壤免遭风蚀,显著增加了土壤有机质的输入,因而显著作用于大气C的固存。
Soil respiration is an important biochemical process of soil organic C mineralization decomposition, release of inorganic nutrients. In this study, we analyzed the changes of soil carbon mineralization potential under different years of sand fixation in Shapotou area by means of laboratory culture. After 103 days of indoor culture, the soil CO2-C release showed the trend of 55 cm> 47 mm> 30 mm> 24 mm> 21 mm> flowing dunes and 0-5 cm> 5-10 cm> 10-20 cm in the vertical direction . While the soil carbon mineralization potential in the quicksand area is the highest in 10-20 cm soil layer. The soil carbon mineralization potential, total nitrogen, organic carbon, and electrical conductivity of different soil fixation years are obviously different. Both of them showed an increase with the prolongation of restoration period of vegetation and a decrease with the increase of soil depth. Correlation analysis showed that soil carbon mineralization potential was significantly correlated with soil organic carbon, total nitrogen, C / N, pH, electrical conductivity, temperature, soil moisture content, and soil environmental factors were also significantly correlated. Soil nutrient content was significantly improved with the prolongation of recovery time, and the soil carbon mineralization potential was consistent with the improvement of soil nutrient status. The establishment of artificial sand-fixing vegetation promotes soil microbial activity and is characterized by potential soil respiration. Vegetation recovery and litter accumulation prevent the soil from wind erosion, significantly increase the input of soil organic matter, and thus significantly affect the storage of atmospheric C.