利用Biome-BGC模型模拟黄土区沙棘人工林碳通量时的生理生态参数敏感性  

Sensitivity Analysis of Ecophysiological Parameters for the Simulated Carbon Flux Using the Biome-BGC Model in a Hippophae rhamnoides Plantation in the Loess Region

作　　者：贾畅 王丽娜 唐亚坤 Jia Chang;Wang Lina;Tang Yakun(College of Forestry,Northwest A&F University,Yangling 712100;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100)

机构地区：[1]西北农林科技大学林学院,杨凌712100 [2]西北农林科技大学水土保持研究所,杨凌712100

出　　处：《林业科学》2022年第11期49-60,共12页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目“黄土丘陵区混交林中固氮和非固氮植物水分利用与氮分享的协调机制研究”(41977425);国家重点研发计划项目子课题“黄土丘陵区暖温性草原生态系统碳水通量变化与资源利用过程机制”(2017YFA0604801)。

摘　　要：【目的】分析生态过程模型模拟结果对植被生理生态参数的敏感性,通过优化此类参数提高模型模拟的准确性。【方法】基于黄土丘陵区沙棘人工林2016—2018年的碳通量观测数据,对Biome-BGC模型进行参数优化及模型结果验证。采用扩展傅里叶幅度敏感性检验方法,分析该模型中27个生理生态参数的一阶和总敏感性,探讨不同参数单独或相互作用对模型模拟结果精度的影响,并筛选出高(>0.2)、中(0.1~0.2)等级的总敏感性参数。同时,使用通径分析计算上述敏感性参数对模型模拟碳通量的正、负影响。【结果】参数优化后的Biome-BGC模型能很好地模拟黄土区沙棘人工林碳通量季节动态。敏感性分析表明,新生长的细根碳含量与新生长的叶碳含量比和阴生叶与阳生叶比叶面积比例对该人工林总生态系统生产力(GEP)、生态系统呼吸(RE)和净生态系统生产力(NEP)均具有高的总敏感性,且新生长的细根碳含量与新生长的叶碳含量比对碳通量的一阶敏感性也较高。通径分析表明,新生长的细根碳含量与新生长的叶碳含量比对该人工林GEP、RE和NEP均具有显著的负影响(P<0.001),其主要通过影响叶片和细根碳氮的总量和分配比例来影响光合和呼吸作用。而阴生叶与阳生叶比叶面积比则主要通过影响叶片接收的光照面积和光照强度来影响植物光合和呼吸作用,因而其对沙棘人工林GEP、RE和NEP均有显著的正影响(P<0.001)。【结论】在利用Biome-BGC模型模拟黄土丘陵区沙棘人工林的碳通量时,新生长的细根碳含量与新生长的叶碳含量比和阴生叶与阳生叶比叶面积比是高敏感性参数,优化上述参数能提高Biome-BGC模型模拟的准确性。【Objective】Sensitivity analysis of the ecophysiological parameters in ecological process models was conducted to improve the accuracy of model simulations by optimizing these parameters.【Method】The carbon fluxes observed during 2016—2018 in Hippophae rhamnoides plantation in the Loess Hilly region was used to optimize the parameters of Biome-BGC model and evaluate its applicability and accuracy.The extended fourier amplitude sensitivity test method was used to analyze the first-order sensitivity and total sensitivity of the 27 selected ecophysiological parameters in this model.The effects of these parameters alone or their interactions on the accuracy of simulated carbon fluxes were investigated.The total sensitivity parameters were selected based on high level(>0.2)and medium level(0.1-0.2)criteria.Path analysis was conducted to calculate the positive and negative effects of these parameters on the Biome-BGC model.【Result】The result showed that after optimizing the parameters,the Biome-BGC model was effective at simulating the seasonal dynamics of the carbon fluxes in the H.rhamnoides plantation.Sensitivity analysis indicated that the ratio of new fine root carbon relative to leaf carbon and the ratio of shady leaf area relative to sun leaf area(SLAshade:sun)exhibited high total sensitivity to the gross ecosystem productivity(GEP),ecosystem respiration(RE),and net ecosystem productivity(NEP)in the plantation.The ratio of new fine root carbon relative to leaf carbon also exhibited high first-order sensitivity to the carbon fluxes.Path analysis suggested that the ratio of fine root carbon relative to leaf carbon had significant and negative effects on GEP,RE,and NEP in the H.rhamnoides plantation(P<0.001)through its effects on the relative carbon and nitrogen contents of the leaves and fine roots.In addition,the ratio of shady leaf area relative to sun leaf area had significant and positive effects on the carbon fluxes(P<0.001)through its effects on the intensity and area of light on the leaves.Both

关 键 词：Biome-BGC模型 碳通量 沙棘人工林 敏感性分析 

分 类 号：S718.5[农业科学—林学]