# Bacterial community composition is an important predictor of surface soil fertility across different land use types: a case study in the Three Gorges Reservoir area

## TL;DR

This study shows that human activity reduces soil fertility and changes bacterial communities in a Chinese watershed.

## Contribution

The study identifies bacterial community composition as a key predictor of soil fertility under varying human activity levels.

## Key findings

- Higher human activity correlates with lower soil fertility and microbial metabolic activity.
- Human activity increases bacterial diversity but decreases the abundance of key soil fertility drivers like Proteobacteria and Acidobacteriota.
- Bacterial community composition is a reliable predictor of surface soil fertility in the study area.

## Abstract

Surface soil is a vital component of terrestrial ecosystems and is of great importance for primary productivity. In Zhangjiachong, a small watershed in Zigui County, central China, human activity and erosion cause extensive surface soil degradation. It is still unclear as to what extent human activity influences soil fertility and soil microorganisms in this area.

Soil samples were collected, during spring and autumn, across a series of land use types with different levels of human activity. We assessed soil fertility and microbial communities using 16S rRNA gene sequencing and Biolog ECO-plates.

The results showed that higher levels of human activity were associated with lower soil fertility and microbial metabolic activity, in addition to higher bacterial diversity. Moreover, human activity had negative effects on the relative abundances of Proteobacteria and Acidobacteriota, which were the key drivers of surface soil fertility. Conversely, stronger human activity was associated with lower abundance of Actinobacteriota. This study suggested that human activity had a negative influence on surface soil fertility, and bacterial community composition could be a good predictor of surface soil fertility.