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Abstract The study established experimental transects in undisturbed areas of the Caohai Nature Reserve in Weining, Guizhou Province. The study aims to examine complete successional transects in different landscapes: non-karst, karst, and vegetation restoration, using the spatiotemporal substitution method. It analyzes the distribution patterns of Total potassium (TK) and Avail potassium (AK) in the soil and employs a Generalized Linear Mixed Model (GLMM) to investigate the effects of geomorphology, soil aggregates, and their interactions on the changes in soil potassium(K) elements. Furthermore, it explores the synergistic effects of K cycling during the vegetation restoration process in karst soils. The findings indicated that: (1) In karst areas, the overall TK content was higher than in non-karst areas, while the AK content in the topsoil was higher in non-karst areas. The TK content in the karst areas tended to approach that of the vegetation restoration zone. (2) After restoration, the dominant plants changed from Gramineae to Gramineae + Asteraceae, and the vegetation richness increased, thereby improving the soil fertility and potassium fixation capacity. (3) The GLMM showed that the karst landscape had a significant effect on the TK and AK contents of surface soil. In the early stage of vegetation restoration, the joint effect of soil and vegetation affected the TK and AK contents in soil.

A series of YCe catalysts were prepared using Y-loaded (Y = Cu, Co, Mn) Ce-based metal–organic framework as a precursor. Mn-loaded CeO2 exhibited significantly better catalytic activity in the catalytic oxidation of ethyl acetate (EA) than noble metal catalyst. The relationship between the physicochemical properties of YCe catalysts and catalytic activity was studied by different characterization methods. The enhanced catalytic activity was attributed to the strong interaction between the transition metals and Ce, high specific surface area, abundant lattice defects, more oxygen vacacies and higher Olatt/(Olatt + Oads + Ow) molar ratios. The main intermediates in the oxidation of EA were ethanol, acetic acid, acetone, acetaldehyde and diethyl ether.

Vegetation restoration has always been the focus of ecological research, but the synergistic effect of the soil carbon cycle and vegetation restoration succession process in karst area is still unclear. In this study, the complete succession zones of non-karst, karst, and karst vegetation restoration landforms in a National Nature Reserve, Caohai (Guizhou Province, China), were compared. The content distribution characteristics of SOC, ROC and DOC were investigated, as well as the geomorphology, spatial location and interaction were studied by using GLMM. The results show that the soil types and vegetation coverage of different landforms lead to a decrease in SOC in karst area with an increase in depth. The soil content in karst area was low, and in order to maintain the normal growth of vegetation, the proportion of soil ROC and DOC in SOC must be high, which leads to the order of soil ROC content in unrepaired area > vegetation restoration area > non-karst area. In addition, the content of SOC in the surface layer of the vegetation restoration area was lower than that of the unrepaired area and the non-karst area. The soil microbial activity in the vegetation restoration area is stronger, and more organic carbon was fixed in the plant. The vegetation coverage and diversity increased obviously and markedly as a result of dominant plants changing (from Gramineae to Gramineae + Compositae) in the karst vegetation restoration area, but the soil in the karst area could not provide sufficient nutrition for plants, ultimately resulting in an inverse ratio between surface SOC and vegetation diversity. This study aims to enhance understandings of ecological functions and vegetation restoration in karst areas, as well as responses to regional carbon cycling.