生物结皮恢复过程中土壤生态因子分异特征

 对新疆古尔班通古特沙漠生物结皮恢复过程中土壤因子的动态变化进行关联性测度、方差分析、相关性分析相结合的定量研究,着重分析结皮恢复年限对土壤微生物数量、养分、盐分、土壤酶的影响,有机质与土壤盐分、pH值、土壤酶的线性关系及土壤生态因子间的相关性。结果表明：相对于土层深度,有机养分、土壤酶等生态因子与生物结皮恢复年限的联系更加紧密。结皮恢复年限对全P、全K、有机质、脲酶、真菌的影响极显著（P<0.01）;对速效P、速效K、全N、总盐、中性碱性磷酸酶、蛋白酶的影响显著(P<0.05)。随结皮恢复年限的增加,结皮层和结皮以下土层中有机养分、土壤酶均有不同程度的增加,逐步具备较高的生物学活性,沙土性状变化较快,渐渐形成抗风蚀、抗干扰能力较强的地衣苔藓结皮。结皮恢复过程中pH值与有机质呈显著线性负相关（R2＝0.701,P<0.05）,土壤盐分与有机质存在线性正相关（R2＝0.653）,但显著性不强（P>0.05）。电导率、脲酶、碱性磷酸酶、中性磷酸酶、蛋白酶与有机质存在极为显著的线性正相关（R2分别为0.888、0.993、0.958、0.948、0.911,P<0.01）,土壤生态因子的协调发展和紧密配合促进了生物结皮的恢复。

Differentiation of Soil Variables in Different Succession Stages of Biological Soil Crusts in Gurbantunggut Desert,Northern Xinjiang,China

The present paper mainly dealt with the response of soil variables to biological soil crust succession in Gurbantunggut Desert.The result showed that soil variables obviously changed with the recovery time of biological soil crust.Variance analysis of Between-Subjects Effect showed that the recovery time significantly influenced the quantitative distributions of actinomyces and fungi.ANOVA analysis indicated that the content of total P,total K,organic matter,activity of urease,quantity of fungi significantly differed from each other in different succession stages of biological soil crusts(P<0.01).The content of available P,available K,total N,total salt,and activity of alkaline phosphatase,phosphatase and proteinase were influenced(P<0.05) by recovery time of biological crusts.Although the concentration of nutrient content and the activity of soil enzyme were both increased during the recovery process,pH value decreased in both surface 0~2 cm crust layers and 2~5 cm soil layers.Twelve years after removal of biological crusts,the nutrient and soil enzyme mainly accumulated in 0~2 cm crust layers.The results also showed that there was an obvious negative linear correlation between pH value and soil organic matter(R2=0.701,P<0.05).The electric conductivity,activity of urease,alkaline phosphatase,phosphatase and proteinase had distinct positive linear correlation with soil organic matter(R2=0.888,0.993,0.958,0.948,0.911 respectively,P<0.01).