生物土壤结皮碳释放对水热因子的响应

Abstract

在室内控制条件下，以腾格里沙漠东南缘1964年人工固沙植被区藻类、混生和藓类结皮为对象，研究了3个温度梯度(15℃、25℃和35℃)和7个水分梯度(3%、5%、10%、15%、20%、25%和30%质量含水量)条件下其碳释放特征。在相同水分条件下，BSCs和流沙呼吸速率随着温度的增加而增加，35℃时BSCs和流沙呼吸速率达到最大值。藓类结皮的呼吸速率显著高于其他土壤类型土壤呼吸。藓类结皮Q10为1.40~3.17，藻类结皮为0.81~3.07，混生结皮为0.55~3.84，流沙为1.19~2.16。BSCs类型、水分和温度显著影响BSCs碳释放量(P < 0.001)。水分含量较高的条件下，藻类和混生结皮的呼吸速率受到了明显抑制，而对藓类结皮的呼吸速率影响不显著。 The carbon release of different types of biological soil crusts (BSC) covered soil was measured under different temperatures condition (15˚C, 25˚C and 35˚C) and different soil water content conditions (3%, 5%, 10%, 15%, 20%, 25% and 30%) in fixed sand dunes at the re-vegetated area in Tengger Desert, Northern China. In the same soil water content condition, the carbon release rate of BSCs and sand were increased with temperature increasing, the highest carbon release rate occurred at 35˚C. The carbon release rate of moss crust was significantly higher than other soil types. Q10 value of moss crust was 1.40 - 3.17, algae crust was 0.81 - 3.07, mixed crust was 0.55 - 3.84 and sand was 1.19 - 2.16. BSCs types, soil water content and temperature were significantly affected on carbon release rate (P < 0.001). The results showed that the respiration rate of the algal crust and mixed crust were significantly restrained by higher soil water content; however, moss crust was not significantly influenced.