# Changes in Soil Microorganisms After Planting Idesia polycarpa in the Luohe River Basin

## TL;DR

This study examines how planting a high-oil tree cultivar affects soil bacteria and properties over time in central China.

## Contribution

The study provides new field evidence on soil bacterial community responses during early plantation establishment of Idesia polycarpa.

## Key findings

- Available potassium increased significantly after planting, while soil organic matter showed a decrease–recovery pattern.
- Bacterial richness decreased, evenness increased, and community composition shifted with higher Pseudomonadota and lower Acidobacteriota.
- Soil organic matter and bulk density were primary drivers of bacterial community structure changes.

## Abstract

Idesia polycarpa ‘Yitong 2’ is a high-oil cultivar widely promoted in central China, yet field evidence on how soil bacterial communities respond during early plantation establishment remains limited. Here, we conducted fixed-site monitoring in a newly established ‘Yitong 2’ plantation in the Luohe River Basin (Henan, China). Bulk soil (0–30 cm) was collected before planting (March 2024) and at 3, 6 and 12 months after planting (June 2024, September 2024 and March 2025). Soil physicochemical properties were measured and bacterial communities were profiled by 16S rRNA gene (V3–V4) amplicon sequencing; functional potential was inferred using PICRUSt2. Available potassium increased significantly, whereas soil organic matter showed a decrease–recovery trajectory. Bacterial richness (Chao1) decreased after planting, while evenness increased; Shannon diversity remained stable. Community composition shifted directionally, with higher relative abundance of Pseudomonadota (formerly Proteobacteria) and reduced Acidobacteriota at later stages. PERMANOVA based on Bray–Curtis distances indicated significant temporal differences in community structure. RDA indicated that soil organic matter and bulk density were the primary drivers of community structural variation. Functionally, the overall metabolic framework remained stable, whereas pathways related to genetic information processing and metabolism exhibited significant differences (p < 0.05). By examining both intra-annual dynamics and inter-annual changes in soil bacteria and physicochemical properties following the planting of ‘Yitong 2’, this study clarifies patterns of soil property variation and trajectories of microbial community structure and functional potential, thereby providing a scientific basis for the establishment of high-quality I. polycarpa plantations and the sustainable development of soil ecosystems.