|
|
Abstract Abstract: Soil microorganisms play a crucial role in nutrient cycling across different vegetation ecosystems, with varying vegetation types leading to distinct microbial communities. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) content, as well as their ratios, significantly influence ecosystem nutrient cycling, plant growth, and soil health. This study focused on six typical vegetation types (steppe, desert, savanna, sparse wooded grassland, evergreen coniferous forest, and evergreen needleleaf shrubland) at different elevations in the Helan Mountains of Ningxia. MBC, MBN, MBP, soil total nitrogen (STN), soil organic matter (SOM), soil pH, and soil water content (SWC) were measured, and one-way ANOVA, redundancy analysis (RDA), and variance partitioning analysis (VPA), were employed to explore the distribution patterns of MBC, MBN, and MBP ecological stoichiometry across different elevational vegetation zones and their relationships with soil physicochemical factors. The results showed: 1) The contents of MBC, MBN, and MBP varied significantly with altitude (P<0.05). MBC and MBN initially increased, then decreased, and subsequently rose again with increasing altitude, whereas MBP increased significantly above 1 822 m. All three reached their highest levels in evergreen needleleaf shrubland, with values of 796.02, 47.26, and 24.07 mg/kg, respectively. 2) The MBC: MBN showed no significant difference with altitude, MBC: MBP and MBN: MBP showed a fluctuating trend with elevation, and all three showed a decreasing trend in the high elevation vegetation zone. The lowest values were observed in evergreen needleleaf shrubland. 3) RDA and VPA revealed that STN had a significant effect on the ecological stoichiometric characteristics of MBC, MBN, and MBP (P<0.05). In conclusion, the C, N, and P ecological stoichiometric characteristics varied significantly across different vegetation zones in the Helan Mountains and were primarily influenced by STN.
Key words: Helan Mountain; vegetation belt; soil microorganisms; ecological stoichiometry; soil physicochemical factors
（Acta Laser Biology Sinica, 2025, 34(3): 246-253）
|
|
|
|
|
|
|
|
