尾巨桉人工林火烧迹地土壤呼吸组分特征及其与土壤因子的关系  

Characteristics of soil respiration components and their relationship with soil factors in the burned area of Eucalyptus urophylla×Eucalyptus grandis plantation

作　　者：沈健 何宗明[1,2] 董强 林宇[3] 郜士垒 SHEN Jian;HE Zongming;DONG Qiang;LIN Yu;GAO Shilei(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Chinese Fir Engineering Technology Research Center of the State Forestry and Grassland Administration,Fuzhou 350002,China;Minhou Baisha State-Owned Forest Farm of Fujian Province,Fuzhou 350100,China)

机构地区：[1]福建农林大学林学院,福州350002 [2]国家林业和草原局杉木工程技术研究中心,福州350002 [3]福建省闽侯白沙国有林场,福州350100

出　　处：《生态学杂志》2023年第7期1537-1547,共11页Chinese Journal of Ecology

基　　金：国家自然科学基金资助项目(31800532)资助。

摘　　要：为探究滨海地区人工防护林火烧迹地土壤总呼吸速率及其组分的动态变化规律以及与之相关的影响因素,利用壕沟法区分土壤异养呼吸和自养呼吸,采用Li-8100碳通量自动测定系统,对福建省滨海沙地尾巨桉人工林火烧迹地土壤呼吸进行测定,同时测定0~10 cm处的土壤温度(T10)和土壤体积含水量(W10),分析火烧迹地和对照样地土壤呼吸及其组分与林地水热因子的月动态变化,探讨土壤呼吸速率与土壤温度、土壤水分以及土壤理化性质的相关关系。结果表明:火烧迹地土壤总呼吸、异养呼吸和自养呼吸的月平均速率分别为2.20、1.87和0.33μmol·m^(-2)·s^(-1),对照样地土壤总呼吸、异养呼吸和自养呼吸的月平均速率分别为2.96、2.15和0.81μmol·m^(-2)·s^(-1),火烧迹地土壤呼吸及其组分均显著下降(P<0.05);全年火烧迹地和对照样地土壤呼吸及其组分与T10均表现出极显著指数相关,全年火烧迹地和对照样地土壤总呼吸速率与W10均表现出显著正相关,火烧迹地土壤异养呼吸与W10无显著相关,对照样地土壤异养呼吸与W10表现出极显著正相关,火烧迹地土壤总呼吸和异养呼吸的Q10值相同,且稍低于对照样地的Q10值;林地土壤呼吸速率与土壤NO_(3)^(-)-N、无机氮均存在极显著正相关,与NH_(4)^(+)-N存在显著正相关;在尾巨桉人工林中,林火干扰对土壤呼吸速率有显著影响,土壤异养呼吸和自养呼吸均显著降低。通过建立回归模型可知,土壤总呼吸与土壤温度和体积含水量均显著相关,进一步证明土壤温度和含水量是影响林地土壤呼吸速率的主要因子,且林火干扰还会导致土壤碳氮组分发生改变,从而影响土壤碳排放速率。To explore the temporal variations of the rates of soil respiration and its components in the burned area of plantation forests in coastal regions and related influencing factors,we measured soil respiration in the burned area of Eucalyptus urophylla×Eucalyptus grandis plantation in coastal sandy land of Fujian Province by the Li-8100 car-bon flux automatic measurement system.Soil heterotrophic and autotrophic respirations were distinguished by the trench method.Soil temperature(T 10)and soil volumetric water content(W 10)at a depth of 0-10 cm were meas-ured.The monthly variations of soil respiration and its components and hydrothermal factors were analyzed in the burnt and control plots.The correlations between soil respiration rate and soil temperature,soil moisture,and soil physicochemical properties were analyzed.The results showed that the monthly average rates of soil total respiration,heterotrophic respiration,and autotrophic respiration were 2.20,1.87,0.33μmol·m^(-2)·s^(-1) in the burned plots,and were 2.96,2.15,0.81μmol·m^(-2)·s^(-1) in the control plots,indicating that soil respiration and its components in the burned plots were significantly decreased(P<0.05).Soil respiration and its components in the burnt and control plots had significant exponential correlation with T 10,while the total respiration rate in the burnt and control plots showed a significant positive correlation with W 10.There was no significant correlation between heterotrophic respiration and W 10 in the burnt plots,while soil heterotrophic respiration in the control plots showed significant posi-tive correlation with W 10.The Q 10 values of soil total respiration and heterotrophic respiration were the same in the burned plots,being slightly lower than that in the control plots.Soil respiration rate was positively correlated with soil NO_(3)^(-)-N,inorganic N,and NH_(4)^(+)-N.In E.urophylla×E.grandis plantation,forest fire significantly affected soil respiration rate by reducing soil heterotrophic and autotrophic respiration.

关 键 词：滨海沙地 轻度火烧 自养呼吸 异养呼吸 温度敏感性指数 

分 类 号：S714[农业科学—林学]