不同类型白刺沙丘土壤理化性状与微生物相关性研究

摘要

In order to explore soil-forming processes and to provide basic data for oasis ecological construction, a study has been undertaken that correlates soil microbes with soil physical and chemical properties in different Nitraria sand dunes in the oasis-desert ecotone of Minqin.Results showed significant differences in soil clay, silt,fine sand and coarse sand content among fixed,semi-fixed and flowing sand dunes.Soil nutrients showed a positive correlation with soil clay,silt and fine sand.However,they were negatively correlated with coarse sand.Correlations decreased with increasing soil particle size.The quantity of soil microbes in semi-fixed sand dunes was clearly higher than in fixed and flowing sand dunes.The ecotone exhibits alkaline soils.The older the sand dune the greater the content of organic matter,total nitrogen,total phosphorus,total potassium,hy-drolytic nitrogen,potassium,available phosphorus and CaCO3 .In addition,soil microbes were significantly correlated with the physical and chemical properties of different ages of sand dune,especially bacteria and acti-nomycetes,which showed a prominent negative correlation with pH value.Soil organic matter had a significantpositive correlation with the quantity of these microbes.%利用民勤荒漠绿洲过渡带不同类型白刺沙丘的土壤微生物、土壤理化性状及二者之间的相关性进行研究，旨在探讨白刺沙丘的成土过程，为绿洲生态建设提供基础数据，结果表明，1）固定、半固定和流动沙丘粘粒、粉粒、细砂粒、粗砂粒含量差异较大；土壤养分含量与土壤粘粒、粉粒、细砂粒等细沙物质含量呈正相关性，与粗砂粒含量呈负相关性，表现为土壤养分含量随土壤颗粒的增大，相关性减弱。2）土壤微生物类群数量在半固定沙丘明显高于固定沙丘和流动沙丘。3）过渡带土壤均处于偏碱性状态，有机质、全氮、全磷、全钾、水解氮、速效钾、速效磷和 Ca-CO3含量随沙丘发育年代的增加逐渐增加。4）不同年代沙丘中土壤微生物和土壤理化因子均具较好的相关性，尤其是细菌和放线菌与 pH 值呈显著的负相关关系，土壤有机质含量与三大菌群数量都表现出显著的正相关关系。