【摘要】 为了解冀北山地山杨、白桦次生林根际与非根际土壤酶活性特征及其影响因子，揭示其土壤微生物的养分限制状况，为该地区次生林土壤外源养分添加及维持土壤生态系统稳定性提供科学依据，本研究以冀北山地山杨、白桦次生林根际与非根际土壤为研究对象，测定根际与非根际的土壤理化性质、土壤酶活性，通过酶化学计量比分析土壤微生物的养分限制状况。结果表明：山杨、白桦次生林根际土壤全氮、铵态氮、β-N-乙酰基氨基葡萄糖苷酶活性显著高于非根际；山杨次生林根际土壤pH值、亮氨酸氨肽酶显著小于非根际；白桦次生林根际土壤有机质、酸性磷酸酶活性显著高于非根际土壤；山杨次生林根际的土壤含水率、土壤有机质、硝态氮、全磷、β-1,4-葡萄糖苷酶、酸性磷酸酶与非根际土壤无显著差异，白桦次生林根际的土壤含水率、pH值、硝态氮、全磷、 β-1,4-葡萄糖苷酶、亮氨酸氨肽酶与非根际土壤无显著差异。山杨根际土壤矢量角度(41.10°)显著低于非根际(44.64°),白桦根际与非根际矢量角度无显著性差异，2个树种矢量角度均小于45°,表明两种次生林根际与非根际土壤微生物主要受氮的相对限制。冗余分析表明，硝态氮和土壤含水率分别是根际与非根际土壤酶活性变化的主要驱动因子。更多还原

【Abstract】 The research aims to investigate the soil enzyme activity characteristics and the influencing factors in the rhizosphere and non-rhizosphere zones of secondary mountain Populus davidiana and Betula platyphylla forests in the mountainous regions of northern Hebei and to elucidate the nutrient limitation status of soil microorganisms, thereby providing scientific basis for exogenous nutrient supplementation in secondary forest soils and the maintenance of soil ecosystem stability within this region. Rhizosphere and bulk soils from Populus davidiana and Betula platyphylla secondary forests in the northern Hebei Mountains were selected as research subjects. Soil physicochemical properties and enzyme activities were measured in both rhizosphere and bulk soils, and the nutrient limitation status of soil microorganisms was analyzed using ecoenzymatic stoichiometry. The results indicated that the total nitrogen, ammonium nitrogen, and β-N-acetylaminoglucosidase enzyme activity in the rhizosphere soil of secondary forests of Populus davidiana and Betula platyphylla were significantly higher than those in the bulk soil. Soil pH and leucine aminopeptidase were significantly lower in the rhizosphere of Populus davidiana secondary forest than in the non-rhizosphere. Soil organic matter and acid phosphatase activity were significantly higher in the rhizosphere of Betula platyphylla secondary forest than in the non-rhizosphere. Soil water content, soil organic matter, nitrate nitrogen, total phosphorus, β-1,4-glucosidase, and acid phosphatase in the rhizosphere of the secondary forest of Populus davidiana were not significantly different from the bulk soil. Besides, soil water content, pH, nitrate nitrogen, total phosphorus, β-1,4-glucosidase, and leucine aminopeptidase in the rhizosphere of the secondary forest of Betula platyphylla were not significantly different from that of the bulk soil. The vector angle of the rhizosphere soil(41.10°) of Populus davidiana is significantly lower than that of the bulk soil(44.64°). There is no significant difference in vector angles between the rhizosphere and non-rhizosphere of Betula platyphylla. The vector angles of both tree species were less than 45°, suggesting that soil microorganisms in the rhizosphere and non-rhizosphere of these two secondary forests were primarily nitrogen-limited. Redundancy analysis revealed that nitrate nitrogen and soil moisture content were the primary driving factors influencing enzyme activity in rhizosphere and bulk soils, respectively.更多还原