华北平原冬小麦-夏玉米农田生态系统土壤自养和异养呼吸模型构建  

Soil autotrophic respiration and heterotrophic respiration models for winter wheat-summer maize rotation cropland in the North China Plain

作　　者：吴丹咏 王秀君 雷慧闽[2] WU Danyong;WANG Xiujun;LEI Huimin(Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China;Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京师范大学地理科学学部,北京100875 [2]清华大学水利水电工程系,北京100084

出　　处：《生态学报》2024年第6期2364-2378,共15页Acta Ecologica Sinica

基　　金：国家重点研发计划课题(2021YFD1900604)。

摘　　要：土壤呼吸是陆地生态系统碳循环的重要过程,准确估算土壤呼吸对估算陆地生态系统碳源汇具有重要意义。通过在华北平原典型农田内开展土壤呼吸及其组分的原位观测实验,构建了适用于华北平原冬小麦-夏玉米轮种制农田生态系统的半经验半机理土壤异养呼吸和土壤自养呼吸模型。结果表明,冬小麦-夏玉米农田土壤异养呼吸模型可表达为土壤温度和土壤水分的函数,其中,土壤温度对土壤异养呼吸的影响适合用Arrhenius方程描述,而土壤水分的影响适合用对称的倒抛物线描述。验证表明,该模型的R^(2)和RMSE分别为0.68和0.52μmol m^(-2)s^(-1)。土壤自养呼吸模型包括维持呼吸和生长呼吸两个模块,其中,维持呼吸表达为土壤温度和叶面积指数的函数,其形式分别为Van′t Hoff指数方程和米氏方程;生长呼吸表达为总初级生产力与维持呼吸之差的线性函数。冬小麦季和夏玉米季土壤自养呼吸模型的结构相同,但是两种作物的模型参数差异较大。验证表明,冬小麦季土壤自养呼吸模型的R2和RMSE分别为0.64和0.50μmol m^(-2)s^(-1),夏玉米季土壤自养呼吸模型的R2和RMSE分别为0.67和0.37μmol m^(-2)s^(-1)。相比于不区分土壤异养呼吸和土壤自养呼吸的土壤总呼吸模型,本研究构建的土壤异养呼吸和土壤自养呼吸模型能够更加准确地模拟土壤呼吸的季节变化和年际变化过程,可为华北平原冬小麦-夏玉米轮种制农田生态系统的土壤呼吸估算提供方法依据。Soil respiration is an important process of carbon cycle in terrestrial ecosystem.Accurate estimation of soil respiration is of great significance for estimating terrestrial carbon sinks and carbon sources.The semi-mechanistic models of soil heterotrophic respiration and soil autotrophic respiration were developed for the winter wheat-summer maize rotation cropland through in situ observations of soil respiration and its components in a typical cropland in the North China Plain.The results showed that the soil heterotrophic respiration model for the winter wheat-summer maize cropland could be expressed by a function of soil temperature and soil moisture.In the soil heterotrophic respiration model,the effect of soil temperature on soil heterotrophic respiration was described by the Arrhenius equation,and the effect of soil moisture on soil heterotrophic respiration was described by the quadratic equation of symmetric inverted parabola appropriately.Based on the validation by the filed observation,the values of R2 and RMSE for the soil heterotrophic respiration model were 0.68 and 0.52μmol m^(-2)s^(-1),respectively.The soil autotrophic respiration model consisted of two modules:the maintenance respiration module and the growth respiration module.In the maintenance respiration module,maintenance respiration was expressed by a function of soil temperature and leaf area index;in this function,the effect of soil temperature was described by the Van't Hoff exponential equation,and the effect of leaf area index was described by the Michaelis-Menten equation.In the growth respiration module,growth respiration was expressed by a linear function of the difference between gross primary production and maintenance respiration.The structures of soil autotrophic respiration models were the same for winter wheat and summer maize while the parameters for the soil autotrophic respiration models were quite different between the two crops.Based on the validation by the filed observation,the values of R^(2) and RMSE for the soil auto

关 键 词：土壤异养呼吸 土壤自养呼吸 半经验半机理模型 冬小麦-夏玉米 华北平原 

分 类 号：S512.11[农业科学—作物学] S513