摘要
为揭示祁连山区植被—土壤—微生物生态系统的关系,以祁连山区不同海拔植被带(祁连圆柏林:2830 m(E1)、2860 m(E2)和2890 m(E3);林草过渡带:2900 m(E4);高山草甸:2920 m(E5))0~40 cm土壤为研究对象,采用磷脂脂肪酸(PLFA)标记法结合土壤理化性质特征,解析不同海拔植被带土壤微生物群落结构的分布规律及其影响因子。结果表明:1)不同海拔植被带土壤中共检测出31种PLFA标记物,E3土壤中PLFA标记物种类(28种)和质量摩尔浓度(770.55±23.77)nmol/g均显著高于其他海拔(P<0.05),5个海拔植被带土壤中微生物PLFA标记物质量摩尔浓度较高的类型是15:0 iso、16:00、18:1 w7c、18:1 w9c和16:010-methyl;土壤微生物群落组成中细菌的比例最大,原生动物的比例最小;2)除原生动物,不同海拔植被带土壤微生物各类群PLFA质量摩尔浓度均呈E3>E2>E4>E5>E1的趋势。随土层深度增加,PLFA标记物质量摩尔浓度在E1、E2和E3中呈递减的趋势,而E4、E5呈增加的趋势;3)主成分分析结果表明,与土壤微生物PLFA群落结构相关的2个主成分的解释变异量分别为57.35%和35.73%,基本可区分不同海拔微生物群落特征。进一步将主成分得分系数与各微生物类群PLFA进行相关分析,31个微生物PLFA中有27个与主成分1显著相关,18个与主成分2显著相关(P<0.05)。冗余分析结果表明第1和第2排序轴的解释量分别为89.45%和5.04%;土壤微生物各类群与pH值,黏粒和粉粒体积分数呈负相关关系,与土壤含水率、砂粒体积分数、全碳质量分数、全氮质量分数和C/N呈正相关关系(P<0.05)。祁连山区土壤微生物群落多样性随海拔升高呈先升高后降低的单峰趋势,主要受土壤含水率、全碳和全氮含量等因子的影响。
[Background]Soil microbial community structure and distribution characteristics can be used as highly sensitive indicators reflecting environmental changes.The Qilian Mountain is an important ecological security barrier for western China.However,the distribution characteristics of soil microbial community structure and its influencing factorsin this area were rarely reported.[Methods]Soil samples were collected from four soil layers(0-10,10-20,20-30 and 30-40 cm)in different vegetation zones along an altitudinal gradient,i.e.,2830 m(E1),2860 m(E2),2890 m(E3),2900 m(E4)and 2920 m(E5)in Qilian Mountains.Soil microbial community composition and structure among the five elevation gradients were detected using the phospholipidfatty acid(PLFA)labeling method,and their physicaland chemical properties were determined.[Results]1)In total,31 PLFAs were detected from the soil of the five altitudinal gradients,and the total PLFA(28)and content((770.55±23.77)nmol/g)in E3 soil were significantly higher than those in other elevations(P<0.05).The PLFA biomarkers with high content were 15:0 iso,16:00,18:1 w7c,18:1 w9c and 16:010-methyl.The bacteria were the most dominant microorganisms,while the abundance of protozoa was the lowest in these soils.2)Except for protozoa,the PLFA biomarkers’contents of soil microorganisms in different vegetation zones showed a trend of E3>E2>E4>E5>E1.With the increase of soil layers,the contents of PLFA biomarkers tended to decrease in E1,E2 and E3 soil,while increase in E4 and E5 soil.3)Principal component analysis showed that the explanatory variances of the two principal components related to soil microbial PLFA community structure were 57.35%and 35.73%,respectively,which basically distinguished the microbial community characteristics at different altitudes.Correlation analysis of the principal component score with 31 PLFA biomarkers showed that in 27 PLFA biomarkers were significantly correlated with PC1 score and 18 PLFA biomarkers were significantly correlated with PC2 score(P<0.05).The redundancy analysis showed that the first and second ordination axes accounted for 89.45%and 5.04%,respectively.Soil microbial communities were negatively correlated with pH,clay and silt volume fractions,while positively correlated with soil water content,sand volume fraction,total carbon(TC),total nitrogen(TN)and C/N(P<0.05).[Conclusions]Variations in soil water content,soil TC and TN contents resulted from altitude gradients could have a strong influence on soil microbial community diversity.
作者
朱庆征
冯志培
冯二朋
张广渊
孔玉华
ZHU Qingzheng;FENG Zhipei;FENG Erpeng;ZHANG Guangyuan;KONG Yuhua(College of Forestry,Henan Agricultural University,450002,Zhengzhou,China;Xining Forestry Research Institute,810000,Xining,China)
出处
《中国水土保持科学》
CSCD
北大核心
2023年第6期32-42,共11页
Science of Soil and Water Conservation
基金
国家自然科学基金“太行山区侧柏人工林土壤有机碳固存与周转机理研究”(41501331)。
