摘　要：土壤微生物在不同植被生态系统的养分循环中起着至关重要的作用，不同植被形成不同的微生物群落。而土壤微生物生物量碳（MBC）、微生物生物量氮（MBN）、微生物生物量磷（MBP）含量及其比值对生态系统的养分循环、植物生长和土壤健康具有重要的影响。本研究以宁夏贺兰山不同海拔高度的6个典型植被类型（草原、荒漠、落叶阔叶灌丛、疏林草原、常绿针叶林和常绿针叶灌丛）作为研究对象，分别测定MBC、MBN、MBP、土壤全氮（STN）、土壤有机质、土壤pH值和土壤含水率，并运用单因素方差分析、冗余分析、方差分解分析等分析方法，解析MBC、MBN、MBP生态化学计量在不同海拔的植被带分布特征与土壤理化因子之间的关系。结果表明：1）MBC、MBN、MBP含量沿海拔变化差异显著（P<0.05），MBC、MBN含量随海拔升高呈现先上升后下降再上升的变化趋势；MBP在海拔升高至1 822 m后显著上升；三者均于常绿针叶灌丛处含量最高，分别为796.02、47.26 mg/kg和24.07 mg/kg。2）MBC∶MBN随海拔升高无显著差异，MBC∶MBP和MBN∶MBP随海拔升高呈现波动变化趋势，在高海拔植被带中，三者均出现降低的趋势，在常绿针叶灌丛处出现最小值。3）冗余分析和方差分解分析显示，STN显著影响MBC、MBN、MBP生态化学计量特征（P<0.05）。综上所述，贺兰山不同植被带C、N、P生态化学计量特征差异显著，且主要受到STN的显著影响。
关键词：贺兰山；植被带；土壤微生物；生态化学计量；土壤理化因子
中图分类号：Q938                         文献标志码：A                    DOI：10.3969/j.issn.1007-7146.2025.03.007

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）