滇中华山松林不同季节土壤微生物碳利用效率对氮沉降的响应OA
Soil Microbial Carbon Use Efficiency in Pinus armandii Forests in Central Yunnan Responds to Nitrogen Deposition in Different Seasons
[目的]为揭示氮沉降下滇中华山松林土壤养分、微生物生物量、酶活性、土壤微生物碳利用效率及其季节变化特征,并探究影响土壤微生物碳利用效率(CUE)的关键影响因子.[方法]选取滇中华山松林土壤为研究对象,设置对照 CK[0 g/(m2·a)]、N5[5 g/(m2·a)]、N10[10 g/(m2·a)]、N15[15 g/(m2·a)]、N20[20 g/(m2·a)]和N25[25 g/(m2·a)]6个氮沉降处理,测定分析土壤养分、微生物生物量、酶活性及其生态化学计量特征对微生物碳利用效率的影响.结合偏最小二乘路径模型(PLS-PM)分析,厘清CUE对氮沉降的响应机制.[结果]在不同季节,土壤硝态氮(NO3--N)、有机碳(SOC)、微生物生物量碳、氮、磷(MBC、MBN、MBP)、β-葡萄糖苷酶(BG)、β-N-乙酰氨基酸葡糖苷酶(NAG)、纤维素水解酶(CL)、EEAC:P((BG+CL)/ACP)、EEAC:N((BG+CL)/NAG)及CUE均随氮沉降浓度的增加表现为先升后降趋势,其中在N10处理下NO3--N、MBC、MBP及CUE显著高于CK,分别升高204.77%、35.00%、22.85%、68.68%.土壤养分、微生物生物量、化学计量特征比及CUE总体表现为雨季高于旱季.通过Mantel分析发现,在旱季和雨季CUE与MBC、MBN、CL、NAG和EEAN:P(NAG/ACP)呈显著正相关.经随机森林分析发现,MBP、NAG、CL、NH4+-N和EEAN:P对CUE贡 献 率 较 大;PLS-PM路径模型确定氮沉降是影响CUE的关键因素,氮沉降通过改变养分有效性及微生物量间接促进CUE.[结论]研究结果可为探究区域不同季节CUE对氮沉降的响应机制提供理论依据.
[Objective]This study aims to reveal the characteristics of soil nutrients,microbial biomass,enzyme activities,soil microbial carbon use efficiency(CUE),and their seasonal variations in Pinus armandii forests in central Yunnan under nitrogen deposition,as well as to explore the key influencing factors of CUE.[Methods]Taking the soil of Pinus armandii forests in central Yunnan as the research object,six nitrogen deposition treatments were set up:control CK[0 g/(m²·a)],N5[5 g/(m²·a)],N10[10 g/(m²·a)],N15[15 g/(m²·a)],N20[20 g/(m²·a)],and N25[25 g/(m²·a)].The effects of soil nutrients,microbial biomass,enzyme activities,and their ecological stoichiometric characteristics on microbial CUE were determined and analyzed.Combined with partial least squares path modeling(PLS-PM)analysis,the response mechanism of soil microbial CUE to nitrogen deposition was clarified.[Results]Under different seasons,soil nitrate nitrogen(NO3--N),soil organic carbon(SOC),microbial biomass carbon,nitrogen,and phosphorus(MBC,MBN,MBP),β-glucosidase(BG),β-N-acetylglucosaminidase(NAG),cellulase(CL),EEAC:P((BG+CL)/ACP),EEAC:N((BG+CL)/NAG),and soil microbial carbon use efficiency(CUE)all showed a trend of first increasing and then decreasing with the increase of nitrogen deposition concentration.Among them,under the N10 treatment,NO3--N,MBC,MBP,and CUE were significantly higher than those in CK,increasing by 204.77%,35.00%,22.85%,and 68.68%,respectively.Soil nutrients,microbial biomass,stoichiometric ratios,and CUE were generally higher in the rainy season than in the dry season.Mantel analysis showed that CUE was significantly positively correlated with MBC,MBN,CL,NAG,and EEAN:P(NAG/ACP)in both dry and rainy seasons.Random forest analysis revealed that MBP,NAG,CL,ammonium nitrogen(NH4+-N),and EEAN:P contributed more to CUE.PLS-PM path model identifies nitrogen deposition as a key factor affecting CUE.Nitrogen deposition indirectly promotes CUE by altering nutrient availability and microbial biomass.[Conclusion]The research findings can provide a theoretical basis for exploring the response mechanisms of CUE to nitrogen deposition across different seasons in the region.
梁小玲;张龙;王克勤;宋娅丽;舒海苑;周玉玺;张茜
西南林业大学水土保持学院,昆明 650224西南林业大学生态与环境学院,昆明 650224西南林业大学水土保持学院,昆明 650224西南林业大学水土保持学院,昆明 650224西南林业大学水土保持学院,昆明 650224西南林业大学水土保持学院,昆明 650224西南林业大学生态与环境学院,昆明 650224
农业科技
土壤微生物碳利用效率微生物生物量土壤酶活性化学计量特征华山松林
soil microbial carbon use efficiencymicrobial biomasssoil enzyme activitystoichiometric characteristicsPinus armandii forest
《水土保持学报》 2026 (2)
242-252,11
云南省科技厅面上项目(202401AT070262)云南省农业基础研究联合专项(202301BD070001-059)
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