北京密云油松人工林碳通量组分季节变化及其对环境因子的响应  

Seasonal Variations in Carbon Fluxes and Their Responses to Environmental Factors in a Pinus tabuliformis Plantation Ecosystem in Miyun,Beijing

作　　者：李鑫豪 张德怀 张赵森 李建 曹俊 隗骥超 吴晓朦 田赟[1,2] 刘鹏 于海群 Li Xinhao;Zhang Dehuai;Zhang Zhaosen;Li Jian;Cao Jun;Wei Jichao;Wu Xiaomeng;Tian Yun;Liu Peng;Yu Haiqun(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083;State Key Laboratory of Efficient Production of Forest Resources,Beijing 100083;Beijing Miyun District Landscaping Bureau,Beijing 101599;Beijing Yongding River Leisure Forest Park Management Office,Beijing 100043;Beijing Lülin Shengyuan Greening Engineering Co.,Ltd.,Beijing 102400;The Beijing Center for Forest Resource Planning and Monitoring,Beijing 100193)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]林木资源高效生产全国重点实验室,北京100083 [3]北京市密云区园林绿化局,北京101599 [4]北京市永定河休闲森林公园管理处,北京100043 [5]北京绿林盛源绿化工程有限公司,北京102400 [6]北京市园林绿化规划和资源监测中心,北京100193

出　　处：《林业科学》2023年第7期35-44,共10页Scientia Silvae Sinicae

基　　金：国家重点研发计划(2020YFA0608100);北京园林绿化生态系统监测网络(GJH-2023-027)。

摘　　要：【目的】量化人工林生态系统碳通量组分,探明环境因子对碳通量组分的调控作用,以提高人工林生态系统碳汇功能评估的准确性,为进一步认识气候变化背景下环境因子对人工林生态系统碳循环过程的调控作用提供参考。【方法】以北京市密云区油松人工林生态系统为研究对象,采用涡度相关法(EC)测定油松人工林生态系统净碳交换量,同时对空气温度(Ta)、饱和水汽压差(VPD)、光合有效辐射(PAR)和土壤水分(SWC)等环境要素进行原位连续监测,分析人工林生态系统碳通量组分季节变化特征及其与环境因子的响应关系。【结果】北京密云油松人工林2021年累积生态系统总生产力(GEP)为315 g·m^(-2),呼吸强度(RE)为291 g·m^(-2),净生产力(NEP)为24 g·m^(-2)。GEP和RE在生长季(4—10月)较高,非生长季接近0 g·m^(-2)。日GEP、RE和NEP最大值分别为4.7、3.3和3.1 g·m^(-2)。月最大净光合速率在生长季呈单峰型变化,最大值出现在7月。在生长季和生长旺期,NEP与GEP均呈正相关(P<0.01),决定系数分别为0.68和0.80。不同Ta、VPD、SWC条件下NEP与PAR间的关系无明显差异。NEP和GEP均随Ta、VPD和SWC增加先增加后降低,峰值分别出现在约25℃、10 hPa、0.2 m^(3)·m^(-3)。低SWC对NEP、GEP和Ta、VPD间的关系无明显影响,但降低RE的温度敏感性。【结论】北京密云油松人工林生态系统在生长旺期、生长季和全年均表现为碳汇,且NEP变化主要受GEP主导。高Ta、VPD和SWC均通过限制GEP降低NEP。低SWC对NEP、GEP和Ta、VPD的关系无明显影响,但降低RE对温度的敏感性。【Objective】This study aims to quantify carbon fluxes in plantation ecosystem and examine the role of environmental factors in regulating carbon fluxes,so as to improve the accuracy in assessing carbon sequestration function in plantation ecosystem.【Method】The eddy-covariance(EC)technique was used to continuously monitor ecosystem carbon fluxes in a typical Pinus tabuliformis plantation ecosystem in Miyun,Beijing in 2021.Air temperature(Ta),vapor pressure deficit(VPD),photosynthetically active radiation(PAR),and soil water content(SWC)were continuously monitored in situ.The seasonal variation characteristics of ecosystem carbon fluxes and their responses to environmental factors were examined.【Result】The cumulative annual gross ecosystem production(GEP),annual ecosystem respiration(RE),and net ecosystem production(NEP)in 2021 were 315,291,and 24 g·m^(−2),respectively.GEP and RE were higher in the growing season(from April to October)and however,they were close to 0 g·m^(−2) in the non-growing season.The maximum daily GEP,RE,and NEP were 4.7,3.3,and 3.1 g·m^(−2),respectively.The monthly maximum carbon assimilation rate was unimodal during the growing season,with its maximum in July.NEP had positive relationships with GEP(P<0.01)during the growing season and the peak growing season,and the coefficients of determination were 0.68 and 0.80,respectively.The relationships between NEP and PAR in different Ta,VPD,and SWC conditions were not significantly different.The responses of NEP and GEP to Ta,VPD,and SWC were all unimodal,peaking at about 25℃,10 hPa,0.2 m^(3)·m^(-3),respectively.Low soil moisture had no significant effect on the responses of NEP and GEP to Ta and VPD,while it reduced the temperature sensitivity of RE.【Conclusion】This study has found that P.tabuliformis plantation ecosystem in the study area is carbon sink during the growing season,the peak growing season,and the whole year.The change in NEP is mainly dominated by change in GEP.High Ta,VPD,and SWC all reduce NEP by limitin

关 键 词：生态系统净生产力 生态系统总初级生产力 生态系统呼吸 油松人工林 

分 类 号：S718.43[农业科学—林学]