摘要
土壤微生物生物量作为土壤中活的有机质部分,是评价土壤有机养分循环通量和周期的重要生态指标.探究干旱半干旱山地生态系统土壤微生物生物量C、N、P生态化学计量特征的垂直分异规律及其关键影响因素,可为了解干旱半干旱山地生态系统土壤C、N、P循环过程及调控机制提供参考.本研究以宁夏贺兰山不同海拔6个典型地带性植被类型作为研究对象,分别测定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)含量和土壤有机碳(SOC)、全氮(TN)、全磷(TP)含量,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,解析土壤微生物生物量C、N、P生态化学计量特征的垂直分异特征与气候因子和土壤理化因子之间的关系.结果表明:1)土壤微生物生物量C、N、P含量沿海拔变化差异显著(P＜0.05),MBC、MBP含量随海拔升高呈现先上升后下降的变化趋势,MBN随海拔升高呈上升趋势,三者均于亚高山灌丛处含量最高,含量分别为1 502.08、35.42 和 127.55 mg.kg-1;2)MBC∶MBP、MBN∶MBP、MBC∶MBN 均随海拔升高呈现波动变化趋势,MBC∶MBP、MBN∶MBP在浅山灌丛处有最大值;3)冗余分析与方差分解分析显示,TN、年均温度(MAT)、pH、TN∶TP是显著影响土壤微生物生物量C、N、P生态化学计量特征的因子(P＜0.05),土壤理化因子较海拔、气候因子对土壤微生物生物量C、N、P生态化学计量特征的影响更大.研究结果表明,土壤理化因子的变化能够引起土壤微生物生物量C、N、P生态化学计量特征的显著变化.
Abstract
Soil microbial biomass,as the living organic matter portion of the soil,is an important ecological indicator of the flux and cycle of soil organic nutrient cycling.Investigating the vertical differentiation patterns and key influencing factors of the ecological stoichiometry characteristics of soil microbial biomass carbon(C),nitrogen(N),and Phosphorous(P)in arid and semi-arid mountainous ecosystems can provide references for understanding the processes and regulatory mechanisms of soil C,N,and P cycles in these ecosystems.This study focused on six typical zonal vegetation types at different altitudes in the Helan Mountains of Ningxia.We measured the soil microbial biomass carbon(MBC),microbial biomass nitrogen(MBN),microbial biomass phosphorus(MBP),and soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP).Using methods such as one-way analysis of variance,redundancy analysis,and variance partitioning analysis,the vertical differentiation characteristics of the ecological stoichiometry of soil microbial biomass C,N,and P and their relationships with climatic factors and soil physicochemical factors were analyzed.The results showed that the contents of soil microbial biomass C,N,and P varied significantly with altitude(P＜0.05).MBC and MBP showed a trend of first increasing and then decreasing with increasing altitude,while MBN increased with altitude.All three elements were highest in the subalpine shrub zone,with contents of 1 502.08,35.42,and 127.55 mg·kg-1,respectively.The ratios of MBC∶MBP,MBN∶MBP,and MBC∶MBN fluctuated with altitude.MBC∶MBP and MBN∶MBP showed the highest values in the shallow mountain shrub zone.Redundancy analysis and variance partitioning analysis indicated that TN,mean annual temperature,pH,and TN:TP significantly affected the ecological stoichiometry characteristics of soil microbial biomass C,N,and P(P＜0.05).Soil physicochemical factors had a greater impact on the ecological stoichiometry characteristics of soil microbial biomass C,N,and P than did altitude and climatic factors.These results suggest that changes in soil physicochemical factors can significantly alter the ecological stoichiometry characteristics of soil microbial biomass C,N,and P.
基金项目
宁夏自然科学基金项目(2022AAC05007)
宁夏贺兰山自然保护区管理局资助项目(NLH2019-280-3)
国家自然科学基金项目(42001095)
国家科技期刊平台
NSTL
万方数据