Slope aspect affects the soil microbial communities in karst tiankeng negative landforms

Area of Science:

• Ecology
• Microbiology
• Geomorphology

Background:

• Karst tiankeng ecosystems are large, negative surface terrains.
• Slope aspects influence soil conditions, vegetation, and microbial flora within tiankeng.
• The specific impact of slope aspect on tiankeng soil microbial communities remains unclear.

Purpose of the Study:

• To investigate the influence of slope aspect on soil microbial community structure and functional potential in karst tiankeng.
• To compare microbial communities on shady and sunny slopes using metagenomic sequencing.

Main Methods:

• Metagenomic sequencing was employed to analyze soil samples from shady and sunny slopes.
• Analysis included microbial community structure, functional potentials, and gene abundance (e.g., CAZy genes).
• Statistical analyses like Linear Discriminant Analysis (LDA) and LEfSe were used to identify biomarkers.

Main Results:

• Microbial diversity (Shannon-Wiener) was higher on shady slopes compared to sunny slopes.
• Significant differences in beta-diversity were observed between slopes, with distinct microbial biomarkers identified (Actinobacteria, Chloroflexi, Proteobacteria).
• Functional pathways, including those related to human disease on sunny slopes and litter decomposition (CAZy genes) on shady slopes, showed significant responses to slope aspect. Microbial communities correlated with vegetation and soil properties (SOC, pH).

Conclusions:

• Slope aspect exerts a significant influence on the composition, structure, and function of soil microbial communities in karst tiankeng.
• Topographical factors, specifically slope aspect, are critical for karst tiankeng biodiversity conservation.
• Future conservation efforts should prioritize topographical considerations in karst environments.