Zhang Rongao, Liu Yijun, Cheng Fei
Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, College of Forestry, Guangxi University, Nanning 530004, China.
Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China.
Microorganisms. 2025 Mar 3;13(3):578. doi: 10.3390/microorganisms13030578.
Soil aggregates play a crucial role in maintaining the health and stability of artificial forest soil ecosystems, and microorganisms contribute to the formation and maintenance of soil aggregates. However, the impact of different tree species in mixed forests on soil aggregate microbial communities remains unclear. In this study, high-throughput sequencing technology was employed to analyze the bacterial and fungal diversity and community composition of four soil aggregate sizes (<0.25 mm, 0.25-1 mm, 1-2 mm, and >2 mm) in pure plantations (CK), mixed and plantations (MCA), mixed and plantations (MCP), and mixed and plantations (MCM). The results indicate that (1) establishing mixed forests enhances the diversity of bacterial and fungal communities in soil aggregates, and that soil aggregates with size <0.25 mm support higher microbial diversity. (2) The fungal and bacterial composition of soil aggregates in mixed forests differs from that of pure forests. The dominant bacterial phyla in the four forest types are Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi. The dominant fungal phyla are Basidiomycota, Ascomycota, Mortierellomycota, and Mucoromycota. (3) PCoA analysis reveals that compared to pure forests, mixing with (MCA) results in marked changes in the bacterial community structure of soil aggregates; similarly, mixing with (MCA) and (MCM) leads to significant differences in the fungal community structure of soil aggregates. (4) RDA results show that NH-N, pH, and OC are the main factors influencing microbial diversity in soil aggregates. In terms of dominant microorganisms, pH and AP are the key environmental factors affecting the structure of bacterial and fungal communities in soil aggregates. The findings of this study contribute to our understanding of the characteristics of microbial communities in soil aggregates affected by tree mixing and provide a scientific reference for the maintenance and enhancement of soil fertility in planted forests.
土壤团聚体在维持人工林土壤生态系统的健康和稳定性方面发挥着关键作用，而微生物有助于土壤团聚体的形成和维持。然而，混交林中不同树种对土壤团聚体微生物群落的影响仍不清楚。在本研究中，采用高通量测序技术分析了纯林（CK）、与[树种A]混交林（MCA）、与[树种B]混交林（MCP）和与[树种C]混交林（MCM）中四种土壤团聚体大小（<0.25毫米、0.25 - 1毫米、1 - 2毫米和>2毫米）的细菌和真菌多样性及群落组成。结果表明：（1）营造混交林可提高土壤团聚体中细菌和真菌群落的多样性，且<0.25毫米的土壤团聚体具有更高的微生物多样性。（2）混交林土壤团聚体的真菌和细菌组成与纯林不同。四种森林类型中主要的细菌门为变形菌门、酸杆菌门、放线菌门和绿弯菌门。主要的真菌门为担子菌门、子囊菌门、被孢霉门和毛霉门。（3）主坐标分析显示，与纯林相比，与[树种A]混交（MCA）导致土壤团聚体细菌群落结构发生显著变化；同样地，与[树种A]混交（MCA）和与[树种C]混交（MCM）导致土壤团聚体真菌群落结构存在显著差异。（4）冗余分析结果表明铵态氮、pH值和有机碳是影响土壤团聚体微生物多样性的主要因素。就优势微生物而言，pH值和有效磷是影响土壤团聚体细菌和真菌群落结构的关键环境因素。本研究结果有助于我们了解树木混交影响下土壤团聚体微生物群落的特征，并为人工林土壤肥力维护和提高提供科学参考。
