城市不同功能区绿地土壤有机质和磁化率特征及其相关性研究——以咸阳市为例

Soil Organic Matter and Magnetic Susceptibility Characteristics and Their Correlation of Urban Greenland: a Case Study in Xianyang City

以咸阳市不同功能区绿地为研究对象,对其进行了土壤有机质（烧失量）和磁化率特征研究,并分析了二者的相关关系,结果表明：咸阳城市绿地土壤烧失量波动变化范围在1.75%~10.67%之间,平均值为5.89%,4种功能区绿地土壤的烧失量（有机质）值由大到小依次是：公园绿地〉道路绿地〉居住区绿地〉单位附属绿地。城市绿地土壤低频质量磁化率（χlf）在（79.80~293.90）×10^-8m^3/kg之间,平均值为113.60×10^-8m^3/kg;频率磁化率（χfd）在0.92%~12.16%之间,平均值为5.73%;不同功能区绿地土壤χlf和χfd%总体都偏高,说明土壤中的磁性矿物总体较高,且存在超顺磁性细颗粒;不同功能区绿地土壤的χlf和χfd%呈现出不同的正负相关关系,表征土壤磁化率的强弱程度受人类活动和自然成土过程的共同作用。不同绿地土壤烧失量与其χlf及χfd呈现不同程度的正负相关性,一方面可以说明土壤有机质的主要来源,另一方面,可以印证人类活动对自然成土过程的过度干扰,从而使土壤的理化性质在发生学上的联系相对较弱,或者不存在。

In order to obtain the change information of organic matter and magnetic susceptibility in different urban greenland,the Xianyang was chosen as sample to study. Results show that the fluctuation range of soil ignition loss of urban greenland between 1. 75% ~ 10. 67%,and the average value is 5. 89%. In ranking order of ignition loss in different types of urban greenlands is park greenland road greenland residential greenland accessory greenland. The fluctuation range of low frequency magnetic susceptibility between（ 79. 80 ~ 293. 90） × 10^- 8m^3/kg,and the average value is 113. 60 × 10^- 8m^3/ kg. The fluctuation range of frequency magnetic susceptibility between 0. 92% ~ 12. 16%,and the average value is 5. 73%. The magnetic susceptibility and frequency magnetic susceptibility in different types of urban greenlands are on the high side generally,which represents a high content of magnetic mineral and indicates there are superparamagnetic particles in soil. There are different positive and negative correlation between magnetic susceptibility and frequency magnetic susceptibility which reveals the size of the magnetic susceptibility affected by human activities natural soil-forming process. The ignition loss and magnetic susceptibility,ignition loss and frequency magnetic susceptibility have positive and negative correlation relationship in different degrees,which show that the main source of soil organic matter,and the physical and chemical properties of soil are weak relatively or non-existent on the genetic links because of the transition interference on natural soilforming process by human activities.