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土壤矿物磁性对环境变化具有重要的指示意义。然而,有关中国中东部东亚季风区内土壤矿物磁性随海拔高度的变化规律的研究和讨论尚不多。我们获取了太白山不同海拔高度5个典型植被带下的表土及土壤剖面样品,测量了这些样品的磁化率(χ_(lf))、频率磁化率(χ_(fd))、非磁滞剩磁(ARM)、饱和等温剩磁(SIRM)、反向磁场等温剩磁(IRM_(-300m T)),探讨了不同植被带中土壤矿物磁性特征及其变化。结果显示:(1)不同植被带下,表土矿物磁性差异显著,χ_(lf)、ARM、SIRM之间表现出良好的相关性,随海拔升高呈降低趋势,而IRM_(-300m T)/SIRM随海拔升高而升高。(2)除栓皮栎林外,其他植被带处的土壤剖面χ_(lf)、χ_(fd)、ARM、SIRM随剖面深度加深而降低,IRM_(-300m T)/SIRM随深度加深而升高;此外,低海拔的栓皮栎林与锐齿栎林处土壤剖面磁性的各个指标远高于高海拔土壤剖面磁性指标。(3)表土总体磁性矿物浓度,较细磁畴的SSD颗粒及亚铁磁性矿物浓度与不同植被带所处温度呈现正相关关系,而与其土壤中的有机质含量呈负相关,但受降雨及坡度影响较小。
Magnetic properties of soil minerals are important indicators of environmental changes. However, there is not much research and discussion on the variation of soil minerals with altitude in the East Asian monsoon region of central and eastern China. We obtained the topsoil and soil profile samples from 5 typical vegetation belts at different altitudes in the Taibai Mountains. The magnetic susceptibility (χ_ (lf)), frequency susceptibility (χ_ (fd)), and non-hysteresis remanence (ARM), saturated isothermal remanence (SIRM) and reverse magnetic isothermal remanence (IRM _ (- 300m T)) were used to investigate the magnetic characteristics of soil minerals and their changes in different vegetation zones. The results showed that: (1) Under different vegetation zones, there was significant difference in the magnetism of topsoil minerals. There was a good correlation between χ_ (lf), ARM and SIRM, and decreased with elevation. However, IRM _ (-300m T) / SIRM rises with altitude. (2) The χ_ (lf), χ_ (fd), ARM and SIRM of soil profiles except vegetation of Quercus variabilis forest zone decreased with the deepening of the depth of the profile, and IRM_ (- 300m T) / SIRM increased with depth In addition, the indexes of soil profile in the low altitude Quercus variabilis forest and Sharptooth oak forest were much higher than those in the high elevation soil profile. (3) There is a positive correlation between total magnetic mineral concentration of surface soil and the concentration of SSD particles and ferrimagnetic minerals in finer domains and the temperature in different vegetation zones, but negatively correlated with the content of organic matter in soil. However, Less affected.