Li Wannian, Xie Le, Xu Yuanyuan, Yang Mei
Key Laboratory of National Forestry and Grassland Administration on Cultivation of Fast-Growing Timber in Central South China, College of Forestry, Guangxi University, Nanning, China.
Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China.
Front Microbiol. 2024 Oct 15;15:1464271. doi: 10.3389/fmicb.2024.1464271. eCollection 2024.
Wang Hsie () is an endangered tree species endemic to tropical and subtropical China. However, the acidic red soil areas where it is distributed generally face nutrient limitation. The study of the effects of mixed planting on soil biogeochemical processes contributes to the sustainable management and conservation of .
We selected pure and mixed stands of and collected its rhizosphere and bulk soil samples to clarify the effect of mixed planting on the soil microbial community and the nutrient status.
The results showed that (1) All stands were strongly acidic phosphorus-deficient soils (pH < 4.0, available phosphorus <10.0 mg·kg). There was a significant rhizosphere aggregation effect for soil organic C, total and available N and K, microbial biomass, and inorganic P fraction. (2) The mixed planting significantly increased the soil water content, organic C, available nutrients, the activities of β-1,4-glucosidase and urease, and microbial biomass. The inorganic P fractions are more influenced by rhizosphere, while organic P fractions are more influenced by tree species composition. (3) Fungi and their ecological functions are more susceptible to tree species than bacteria are, and have higher community compositional complexity and α-diversity in mixed plantations. And mixed planting can improve network complexity among key microorganisms. (4) The correlation between soil microorganisms and environmental factors was significantly higher in mixed forests than in pure forests. Soil organic C, available N and P, microbial biomass C and N, β-1,4-glucosidase, and stable P fractions were the key environmental factors driving changes in fungal and bacterial communities.
In conclusion, the mixed planting patterns are more advantageous than pure plantations in improving soil physicochemical properties, enhancing nutrient effectiveness, and promoting microbial activities and diversity, especially mixed with is more conducive to soil improvement and sustainable management, which provides practical references for relocation protection of endangered tree species and species selection and soil fertility management in mixed planting. In addition, the study highlighted the key role of rhizosphere microenvironment in soil nutrient cycling and microbial community structure, which provides new perspectives for a deeper understanding of soil-microbe-plant interaction mechanisms.
蚬木（Wang Hsie）是中国热带和亚热带地区特有的濒危树种。然而，其分布的酸性红壤地区普遍面临养分限制。研究混交种植对土壤生物地球化学过程的影响有助于蚬木的可持续管理和保护。
我们选择了蚬木的纯林和混交林，并采集了其根际和非根际土壤样本，以阐明混交种植对土壤微生物群落和养分状况的影响。
结果表明：（1）所有林分均为强酸性缺磷土壤（pH＜4.0，有效磷＜10.0 mg·kg）。土壤有机碳、全氮和有效氮、钾、微生物生物量以及无机磷组分存在显著的根际聚集效应。（2）混交种植显著提高了土壤含水量、有机碳、有效养分、β-1,4-葡萄糖苷酶和脲酶活性以及微生物生物量。无机磷组分受根际影响更大，而有机磷组分受树种组成影响更大。（3）真菌及其生态功能比细菌更容易受到树种的影响，并且在混交林中具有更高的群落组成复杂性和α-多样性。混交种植可以提高关键微生物之间的网络复杂性。（4）混交林中土壤微生物与环境因子之间的相关性显著高于纯林。土壤有机碳、有效氮和磷、微生物生物量碳和氮、β-1,4-葡萄糖苷酶以及稳定磷组分是驱动真菌和细菌群落变化的关键环境因子。
总之，混交种植模式在改善土壤理化性质、提高养分有效性、促进微生物活动和多样性方面比纯林更具优势，尤其是蚬木与[未提及树种名称]混交更有利于土壤改良和可持续管理，为濒危树种迁地保护以及混交种植中的树种选择和土壤肥力管理提供了实践参考。此外，该研究突出了根际微环境在土壤养分循环和微生物群落结构中的关键作用，为深入理解土壤-微生物-植物相互作用机制提供了新的视角。
