Aims To explore the responses of soil microbial diversity and community structure to elevation gradient (2,700—3,300 m) in Qinghai spruce forest on the northern slope of Qilian Mountain, and to reveal the vertical distribution and driving mechanism of microbial community in climate change sensitive areas. Methods Soil profile samples (0—60 cm depth) were collected at an altitude of 2,700—3,300 m. Bacterial (16S rRNA gene) and fungal (ITS region) community structure was analyzed by Illumina sequencing technique; soil physical and chemical properties such as bulk density (BD), pH, soil organic carbon (SOC), total nitrogen (TN), alkaline nitrogen (AHN), microbial biomass carbon and nitrogen (MBC, MBN), as well as slope gradient were simultaneously measured. Results 1) Significant altitudinal differences (P < 0.05) were observed in fungal and bacterial α-diversity. The bacterial community reached its peak α-diversity at 3,300 m. The fungal community also exhibited its highest richness (as measured by Chao1 and ACE indices) at 3,300 m. 2) Abundance of dominant bacterial phyla (Pseudomonadota, Actinomycetota, Gemmatimonadota) was significantly affected by altitude (P < 0.05): Pseudomonadota abundance at 3,300 m was significantly higher than that at 2,900 m and 2,800 m; Actinomycetota and Gemmatimonadota were more abundant at 2,700 m than at 3,300 m (P < 0.05). The dominant phylum of fungal (Basidiomycota, Ascomycota, Mortierellomycota) had no significant altitude difference (P > 0.05). 3) Variation of bacterial communities was driven by pH, MBC, TN, and TP. Fungal community was regulated by slope, pH, BD, TN, TK, MBC, and SOC. 4) Bacterial networks were most complex at 2,850 m and simplest at 3,200 m. Fungal networks were consistently simpler than bacterial networks. Conclusions Altitude gradient significantly impacted the microbial community structure by changing soil physical and chemical properties. Bacterial communities exhibited greater sensitivity to elevation changes than fungal, manifested in diversity peak shifts, community structure changes driven by multiple factors, and more complex network structures.

Altitudinal effects on soil microbial diversity and composition in qinghai spruce forests of qilian mountain

期刊论文
发表日期：

2026年5月7日

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Yiming Feng,
Changming Zhao,
Ling Wang,
Jinhua Li,
Tianwei Wu,
Chunyan Lv,
Ming Jin

摘要

Aims

To explore the responses of soil microbial diversity and community structure to elevation gradient (2,700—3,300 m) in Qinghai spruce forest on the northern slope of Qilian Mountain, and to reveal the vertical distribution and driving mechanism of microbial community in climate change sensitive areas.

Methods

Soil profile samples (0—60 cm depth) were collected at an altitude of 2,700—3,300 m. Bacterial (16S rRNA gene) and fungal (ITS region) community structure was analyzed by Illumina sequencing technique; soil physical and chemical properties such as bulk density (BD), pH, soil organic carbon (SOC), total nitrogen (TN), alkaline nitrogen (AHN), microbial biomass carbon and nitrogen (MBC, MBN), as well as slope gradient were simultaneously measured.

Results

1) Significant altitudinal differences (P < 0.05) were observed in fungal and bacterial α-diversity. The bacterial community reached its peak α-diversity at 3,300 m. The fungal community also exhibited its highest richness (as measured by Chao1 and ACE indices) at 3,300 m. 2) Abundance of dominant bacterial phyla (Pseudomonadota, Actinomycetota, Gemmatimonadota) was significantly affected by altitude (P < 0.05): Pseudomonadota abundance at 3,300 m was significantly higher than that at 2,900 m and 2,800 m; Actinomycetota and Gemmatimonadota were more abundant at 2,700 m than at 3,300 m (P < 0.05). The dominant phylum of fungal (Basidiomycota, Ascomycota, Mortierellomycota) had no significant altitude difference (P > 0.05). 3) Variation of bacterial communities was driven by pH, MBC, TN, and TP. Fungal community was regulated by slope, pH, BD, TN, TK, MBC, and SOC. 4) Bacterial networks were most complex at 2,850 m and simplest at 3,200 m. Fungal networks were consistently simpler than bacterial networks.

Conclusions

Altitude gradient significantly impacted the microbial community structure by changing soil physical and chemical properties. Bacterial communities exhibited greater sensitivity to elevation changes than fungal, manifested in diversity peak shifts, community structure changes driven by multiple factors, and more complex network structures.