根际微生物群落特征和生态系统多功能性(EMF),两者都受到地形因素的影响,密切相关。然而,还需要更有针对性的探索,以充分了解不同土壤层根际微生物群落沿地形梯度的变化,以及他们是否以及如何在特定的现场条件下调节EMF。这里,我们在天津八仙山的六个海拔梯度和两个坡度位置从310到750m之间对胡桃木山林进行了相关研究。结果表明,两层(0-20cm和20-40cm)的根际土壤理化性质和酶活性随海拔的变化而显着变化。虽然仅在顶层,坡度位置对大多数指标有重大影响。坡底和中高海拔的顶层细菌丰富度和多样性较高,真菌的差异并不明显。地形因素和土壤深度都显著影响微生物群落结构,细菌的念珠菌,被孢霉,Sebacina,真菌的水藻属主要导致群落之间的差异。EMF随着海拔的增加而上升,细菌比真菌更重要,和地形因素可以通过改变细菌多样性和优势分类群丰度来影响EMF。为了评估EMF,子层的聚集体结构和顶层的碳循环相关指标具有较高的重要性。我们的结果揭示了所研究林分中根际微生物群落沿地形梯度的深度依赖性特征,以及细菌对EMF的关键调节作用,同时还强调深度是分析土壤特性和EMF的重要变量。这项工作有助于我们更好地了解曼德舒里卡的个人和社区对不断变化的环境条件的反应,为当地和华北地区次生林的管理和保护提供科学参考。
Rhizosphere microbial community characteristics and ecosystem multifunctionality (EMF), both affected by topographic factors, are closely correlated. However, more targeted exploration is yet required to fully understand the variations of rhizosphere microbial communities along topographic gradients in different soil layers, as well as whether and how they regulate EMF under specific site conditions. Here, we conducted relevant research on Juglans mandshurica forests at six elevation gradients and two slope positions ranging from 310 to 750 m in Tianjin Baxian Mountain. Results demonstrated that rhizosphere soil physicochemical properties and enzyme activities of both layers (0-20 cm and 20-40 cm) varied significantly with elevation, while only at top layer did slope position have significant impacts on most indicators. Bacterial richness and diversity were higher in the top layer at slope bottom and middle-high elevation, the difference in fungi was not as noticeable. Both topographic factors and soil depth significantly impacted microbial community structure, with Candidatus_Udaeobacter of bacteria, Mortierella, Sebacina, and Hygrocybe of fungi mainly contributing to the dissimilarity between communities. EMF rose with increasing elevation, bacteria were more critical drivers of this process than fungi, and topographic factors could affect EMF by altering bacterial diversity and dominant taxa abundance. For evaluating EMF, the aggregate structure of sub layer and the carbon cycle-related indicators of top layer were of higher importance. Our results revealed the depth-dependent characteristics of the rhizosphere microbial community along topographic gradients in studied stands, as well as the pivotal regulatory role of bacteria on EMF, while also highlighting depth as an important variable for analyzing soil properties and EMF. This work helps us better understand the response of individuals and communities of J. mandshurica to changing environmental conditions, further providing a scientific reference for the management and protection of secondary forests locally and in North China.