连作对杨树人工林土壤呼吸及各组分的影响  

Effects of continuous cropping on soil respiration and its components of poplar plantations

作　　者：程学刚[1] 张彩虹[1] 杨焕祥[1] 刘浩栋 付战勇 张光灿[1] 李传荣[1] CHENG Xuegang ZHANG Caihong YANG Huanxiang LIU Haodong FU Zhanyong ZHANG Guangcan LI Chuanrong(Taishan Forest Ecosystem Research Station, Key Laboratory of Agricultural Ecology and Environment of Shandong Agricultural University, 271018, Tai＇an, Shandong, China)

机构地区：[1]泰山森林生态系统国家定位观测研究站山东农业大学农业生态与环境重点实验室,山东泰安271018

出　　处：《中国水土保持科学》2017年第1期105-112,共8页Science of Soil and Water Conservation

基　　金：国家林业公益性科研专项"森林生态服务功能分布式定位观测与模型模拟"(201204101-7);国家自然科学基金"黄泛平原农田林网的生态因子场形成机制的研究"(31170662);教育部博士点基金"基于生态因子场的拟法正农田林网可持续更新机制研究"(20133702110007)

摘　　要：土壤呼吸是整个陆地生态系统碳循环的关键过程之一。以山东大汶河沿岸沙地不同连作代数杨树人工林(1代林、2代林和3代林)为研究对象,利用ACE自动土壤呼吸监测系统(UK),对3种林分一个生长季(4—10月)的土壤呼吸速率及温湿度进行测定,同时采用壕沟法对3种林分的土壤呼吸进行组分分离,并对土壤呼吸及各组分与土壤温湿度的关系进行模型模拟。结果表明:3种林分的土壤呼吸速率(RS)、自养呼吸速率(R_A)和异养呼吸速率(RH)的月变化均为明显的单峰格局;生长季内,3种林分R_A贡献率月差异明显,平均贡献率为40.04%;RS及其组分与5 cm处土壤温度存在显著指数关系,与土壤体积含水量没有相关性,土壤温度与土壤体积含水量的复合模型对土壤呼吸速率变化解释能力为80%~94%;3种林分生长季平均土壤呼吸速率分别为3.12、3.08和2.66μmol/(m2·s),3代林RS和RH均显著低于1代林和2代林。连作导致杨树人工林地土壤呼吸速率减弱,土壤理化性质和微生物量的差异是导致林分间土壤呼吸速率差异的主要原因。揭示连作对杨树人工林土壤呼吸及各组分的影响,以及作用机制,为全面探究杨树人工林连作效应及土壤碳循环,提供数据支撑。[Background] Soil respiration（ RS） is a key step in the carbon cycle of forest ecosystem,which mainly consists of two parts： autotrophic respiration（ RA） and heterotrophic respiration（ RH）. The decisive factors of autotrophic and heterotrophic respiration are different. In addition,the heterotrophic and autotrophic components of soil respiration may respond differently to climate change. Our goal is to assess the relationship between soil respiration and soil temperature and humidity,to determine the relative contribution of autotrophic and heterotrophic respiration to soil respiration,and to investigate the effect of continuous cropping on soil respiration and its components. The study site is located in the sandlot along the Dawen River,Shandong Province of eastern China. [Methods]We took different continuous cropping generations of poplar plantation（ i. e. first generation,second generation and third generation） as theresearch objects. We used a field setup through trenching method to distinguish between heterotrophic and autotrophic respiration,and ACE automatic soil respiration monitoring system to measure the dynamics of soil respiration during the growing season in 2015. Meantime,soil temperature and soil water content at5 cm depth were also measured by the self-contained temperature and moisture sensor of the instrument mentioned above. We used three empirical models to fit and analyze the relationship between soil respiration,soil temperature and volumetric water content. In addition,the soil bulk density,p H value,soil organic carbon（ SOC）,total nitrogen（ TN） and microbial biomass carbon（ MBC） content in0- 20 cm soil depth of three forest types were observed. [Results]1） Soil respiration and its components presented significant monthly variation as unimodal pattern,and were consistent with the change of soil temperature. 2） The average soil respiration rate of three forest types on their growth seasons were3. 12 μmol /（ m2·s）,3. 08 μmol/（ m2·s） and 2. 66 μm

关 键 词：自养呼吸 连作 异养呼吸 壕沟法 

分 类 号：S718.55[农业科学—林学]