Slope Aspect Affects The Soil Microbial Communities In Karst Tiankeng Negative Landforms

Abstract

Background: Karst tiankeng is a large-scale negative surface terrain, and slope aspect affect the soil conditions, vegetation and microbial flora in the tiankeng. However, the influence of the slope aspect on the soil microbial community in tiankeng has not been elucidated. Methods: In this study, metagenomic sequencing technology was used to analyzed the soil microbial communities and metabolic function on the shady and sunny slopes of karst tiankeng. Results: The Shannon-Wiener diversity of microbial communities on shady slopes was significantly higher than that on shady slopes. Shady and sunny slopes have similar microbial community composition, but there are differences in abundance. The linear discriminate analysis (LDA) results showed that biomarkers mainly belongs to Actinobacteria, Chloroflexi and Proteobacteria. Functional pathways and CAZy (Carbohydrate-Active Enzymes) genes also had a remarkable response to slope aspect change. LEfSe results indicated several biomarker pathways in sunny slope involved in human disease. Moreover, the abundance of CAZy genes was higher in shady slope and had stronger ability in decomposing litter. The microbial communities were mainly correlation with the vegetation characteristics (species richness and coverage) and soil properties (SOM and pH). Conclusions: These results indicate slope aspect has a pronounced influence on microbial community composition, structure and function at karst tiankeng. In the future, the conservation of karst tiankeng biodiversity should pay more attention to topographical factors.

A novel method for cliff vegetation estimation based on the unmanned aerial vehicle 3D modeling

“…Calculation of vegetation cover in special and small-scale areas (such as sinkholes and cliffs) requires the use of aerial remote sensing and ground measurements such as terrestrial lidar and artificial climbing sampling (Boggess et al, 2021). So far, few studies have explored the vegetation coverage of cliffs, examples of which are the Tiankeng sinkhole (Jiang et al, 2021) and cliff flora (Strumia et al, 2020). The main difficulty of currently available cliff vegetation coverage measurements is that the cliffs are too high to allow for obtaining a manual control group, and it is difficult to efficiently conduct surveys on a large scale.…”