Abstract: We compared the distribution and influencing factors of heavy metals and rare earth elements in soils of Chenqi catchment in Puding, Guizhou and Jiulong River catchment in Fujian, China, and investigated the geochemical cycling processes and environmental effects of soil elements in both Earth’s critical zones. The results showed that Cr, Zn, Ni, Cu, and Pb contents in topsoils from Puding were higher than that from Jiulong River catchment, which were mainly associated with the leaching and geological background of the catchments. The contents of most heavy metals in cropland, shrub land, and abandoned cropland were higher than that in grassland and secondary forest in Puding, while the contents of some heavy metals in abandoned tea plantation were higher than that in forest in Jiulong River catchment. This may be related to atmospheric deposition and agricultural activities. The contents of rare earth elements in Puding soils (145-248 mg·kg^-1) were higher than that in Jiulong River catchment (51-173 mg·kg^-1), which was attributed to the formation process of karst soil in Puding and parent rock in Jiulong River catchment. Results of the ecological risk analyses showed low ecological risk in Puding soils and forest soils in Jiulong River catchment, while moderate ecological risk occurred in abandoned tea plantation in Jiulong River catchment, with a high ecological risk of Cd.

Key words: Earth’s critical zone, Puding Chenqi catchment, Jiulong River catchment, heavy metal element, rare earth element, ecological risk assessment.