古尔班通古特沙漠生物土壤结皮影响下的土壤酶分布特征

 对古尔班通古特沙漠典型沙垄生物土壤结皮分布区的土壤酶分布特征进行了定量研究。结果表明：①土壤酶的分布在典型沙垄的不同地貌部位具有空间异质性，表现为垄间低地>沙垄坡部>垄顶，垄顶与垄间低地的过氧化氢酶、脲酶、中性磷酸酶、碱性磷酸酶、蛋白酶活性存在极显著差异（P<0.01）;②垂直分布上，土壤酶的积累以表层0～2 cm为主，随土壤深度增加显著递减，以垄间低地表现的尤为明显;③地貌部位与土层深度的交互效应对中性磷酸酶、碱性磷酸酶、转化酶均有极显著影响（P<0.01）;④相关性分析表明，有机质、全N是影响土壤酶活性的重要因素；各种酶促反应既是专性的，又是相互联系的；⑤主成分分析表明，过氧化氢酶和脲酶能够较好地反映土壤综合状况，与大多数土壤因子均呈极显著相关（P<0.01）。尤其是脲酶，能够作为反映典型沙垄生物土壤结皮区土壤肥力的主要指标。

Distribution Characters of Soil Enzymes in Longitudinal Dune Areas of Gurbantunggut Desert Covered by Biological Soil Crusts

The paper mainly dealt with the distribution characteristics of soil enzymes in longitudinal dunes of the southern part of Gurbantunggut desert covered by biological soil crusts. The results showed that: (1) Soil enzymes activities at each depth of soil layers gradually decreased from inter-dunes lowlands to slope of sand dunes and to dune crests. (2) Soil enzymes mainly accumulated in 0~2 cm soil layer at each location of longitudinal dunes, especially in inter-dune valley where lichen and moss crusts grew well. (3) There were distinctly positive linear correlations between the activity of soil enzymes and soil organic matter, total N (P<0.01). The interaction of soil enzymes activities was observed. The principal component analysis results showed that soil enzymes (especially urease) activities could be regard as a comprehensive index of soil fertility.