YAO Nai-ci1, ZHAO Min-shuang1, ZHANG Zhi-dan1*, ZHANG Jin-jing1*, HE Nian-peng2, ZHONG Jia-jun3
（1.College of Resource and Environmental Science，Jilin Agricultural University，Changchun 130118, China;
2. Key Laboratory of Ecosystem Network Observation and Simulation, Institute of Geographic Sciences and Resources, Chinese Academy of Sciences Northeast Institute of Geography and Agroecology, Beijing 100101, China;
3. Experiment Station of Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China)
Abstract: In this article, taking forest soils in seven different climate zones in China as the research object, started with the influences of different temperatures and meteoric waters on various forest soils, by using a combination of field sampling and indoor analysis, the cation exchange capacity, particle component, and chemical composition characteristics of forest soils have been measured. By using the selective dissolution and X-ray diffraction analysis methods, the XRD phase characteristics of clay minerals in different forest soils have been analyzed in order to deeply discuss the component and composition characteristics and content changes of clay minerals in forest soils affected by different temperatures and meteoric waters in different climatic zones. The results show that contents of clay minerals for samples of the seven tested forest soils are more than 30% with the exception of samples from the Wulingshan area. Samples of forest soils from the Wulingshan area belong to loam, those from the Xishuangbanna area belong to sandy clay loam, and those from other areas belong to clay loam. The chemical compositions of clay particles in the seven tested forest soils are composed mainly of SiO2, Al2O3 and Fe2O3, with the subsequently decreased order of Sa values of samples from the Jiaohe, Mohe, Taibaishan, Wulingshan, Tiantongshan, Xishuangbanna, Huanglianshan areas. With the increase of temperatures and amounts of precipitated meteoric waters from the north to south, the Sa and Saf values of forest soils are gradually decreased, but the degrees of soil weathering are increased. The clay minerals of samples in the Mohe area of the cold temperate zone, Jiaohe area of the mid temperate zone, Wulingshan area of the warm temperate zone, and Taibaishan area of the northern subtropical zone mainly belong to the 2:1 type illite, whereas clay minerals of samples in the Tiantongshan area of the central subtropical zone, Huanglianshan area of the southern subtropical zone and Xishuangbanna area of the tropical zone mainly belong to the 1:1 kaolinite. With the increase of temperatures and amounts of precipitated meteoric waters, the contents of illite in samples are gradually decreased, those of smectite are generally decreased, but those of kaolinite are generally increased. This means that clay minerals of the tested forest soils are regularly changed with the climate change at a certain degree.
Keywords: Clay minerals; temperature; precipitated meteoric water; forest soil; XRD
ACTA MINERALOGICA SINICA Vol.41, No.6, 2021, page 668-678
