Ji Shuang, Xie Huichun, Du Shaobo, Zhang Shaoxiong, Dong Zhiqiang, Li Hongye, Qiu Xunxun
College of Geographical Sciences, Qinghai Normal University, Xining 810008, China.
Qilian Mountain Southern Slope Forest Ecosystem Research Station, Haidong 810500, China.
Biology (Basel). 2025 Jul 23;14(8):927. doi: 10.3390/biology14080927.
Understanding the distribution patterns of soil bacterial community structure and diversity across different forest types is essential for elucidating the mechanisms underlying microbial community assembly and its ecological drivers, particularly under the pressures of climate change. In this study, we examined six forest types-including four monocultures and two mixed-species stands-to systematically evaluate the structural composition, diversity metrics, and functional potential of soil bacterial communities. Significant differences in microbial structure and functional composition were observed among forest types. Mixed forests exhibited higher soil nutrient levels, more complex structures, and greater water retention capacity, resulting in significantly higher bacterial and functional diversity compared to monoculture forests. Bacterial diversity was greater in subsurface layers than in surface layers. Surface communities in monoculture forests showed relatively high structural heterogeneity, whereas deeper communities in mixed forests displayed more pronounced differentiation. The dominant bacterial phyla were mainly related to carbon and nitrogen metabolism, compound degradation, and anaerobic photosynthesis. Surface bacterial communities were primarily influenced by catalase activity, alkali-hydrolysable nitrogen, bulk density, and pH, whereas subsurface communities were largely controlled by pH, with supplementary regulation by nitrogen and potassium availability. Therefore, forest type and soil depth jointly influence the diversity, composition, and functional attributes of soil microbial communities by modulating soil physicochemical conditions.
了解不同森林类型中土壤细菌群落结构和多样性的分布模式，对于阐明微生物群落组装及其生态驱动因素的潜在机制至关重要，尤其是在气候变化的压力下。在本研究中，我们考察了六种森林类型，包括四种单一树种林和两种混交林，以系统评估土壤细菌群落的结构组成、多样性指标和功能潜力。在不同森林类型中观察到微生物结构和功能组成存在显著差异。混交林表现出更高的土壤养分水平、更复杂的结构和更强的保水能力，与单一树种林相比，细菌和功能多样性显著更高。地下层的细菌多样性高于表层。单一树种林的表层群落结构异质性相对较高，而混交林较深层的群落分化更为明显。主要的细菌门类主要与碳氮代谢、化合物降解和厌氧光合作用有关。表层细菌群落主要受过氧化氢酶活性、碱解氮、容重和pH值的影响，而地下群落主要受pH值控制，并受氮和钾有效性的补充调节。因此，森林类型和土壤深度通过调节土壤理化条件共同影响土壤微生物群落的多样性、组成和功能属性。
