短期寒潮天气对福州市绿地土壤呼吸及组分的影响  

Effects of short-term cold-air outbreak on soil respiration and its components of subtropical urban green spaces

作　　者：李熙波[1,2] 曾文静[1,2] 李金全[1,2] 黄向华[1,2] 钟羡芳[1,2] 杨玉盛[1,2] 

机构地区：[1]湿润亚热带山地生态省部共建国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州350007

出　　处：《生态学报》2011年第19期5728-5738,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31000321)

摘　　要：城市生态系统土壤呼吸在区域乃至国家尺度上的碳预算与碳循环中都具有重要地位,研究突发天气下城市生态系统土壤呼吸及其组分的变化对准确估算城市土壤碳排放具有重要意义。以亚热带城市草坪(沟叶结缕草,Zoysia matrell)和片林(南洋杉,Araucaria heterophylla)为研究对象,于2011年2月10日至19日通过监测一次突发短期降温天气前后土壤呼吸及其组分(微生物呼吸和根系呼吸)的动态变化,探讨了短期低温天气对城市生态系统土壤呼吸的影响。结果表明:在突发寒潮天气发生后,片林和草坪的土壤温度均显著降低,降温幅度最大分别达7.4℃和5.5℃,二者的土壤呼吸均因降温而骤降,降低比例分别高达79.4%和71.2%。但土壤呼吸及组分也随期间的降水事件而呈现出明显波动。整个观测期间片林土壤呼吸、微生物呼吸与根系呼吸的日均值分别2.54μmol.m-.2s-1、0.76μmol.m-.2s-1和1.78μmol.m-.2s-1,而在草坪中三者分别为1.07μmol.m-.2s-1、0.83μmol.m-.2s-1和0.24μmol.m-.2s-1。土壤温度是控制降温过程中城市绿地土壤呼吸及其组分的关键限制因子并与之呈指数正相关关系,但由于冠层结构简单、耐寒性较低,草坪对温度变化的响应更加敏感。在短期降温中草坪土壤呼吸、微生物呼吸与根系呼吸的Q10值明显提高,分别高达4.18、8.17和18.17。受降水与降温的共同影响,草坪与片林各土壤呼吸类型同时受土壤温度、土壤含水量与降水量的控制,由这3个因子构成的多元回归模型可以较好地拟合各呼吸类型的日均值变化(R2>0.55)。Soil respiration（Rs） from urban ecosystem plays a significant role in local and national carbon budget and cycling.Soil respiration under weather break as an important component of annual carbon balance,may have different mechanism responding to environment factors compared with that under normal weather condition.Therefore,quantifying soil respiration under weather break and determining its key environment factors are crucial for both understanding the belowground carbon balance and building carbon cycling model.However,little information about soil respiration under weather break among different ecosystems is available.Specifically,the data about soil respiration from urban ecosystem is scarce,although urban ecosystem had become a major settlement of human and previous studies have highlighted that urban ecosystem exhibited a high rate of soil respiration.In this study,soil respiration and it components in response to a weather break,cold-air outbreak,were investigated by LI-COR-8100-103 system in two typical urban green spaces,a woodland（Araucaria heterophylla） and a turfgrass（Zoysia matrell）,in the Minjiang Riverside Park of Fuzhou City（26°03′ N,119°15′ E）,Fujian Province,China,during the middle February in 2011.The two components of soil respiration,microbial（Rh） and root respiration（Rr）,were partitioned by trench method.In both ecosystems,cold-air outbreak significantly decreased soil temperature,and inhibited Rs and its components.The degree of decrease of soil temperature in woodland and turfgrass were 7.4℃ and 5.5℃,respectively.And soil respiration of woodland and turfgrass dropped by 79.4% and 71.2%,respectively.However,with the accompanying precipitation,these soil CO2 fluxes also showed great fluctuation.In woodland,the daily mean value of Rs,Rh and Rr were 2.54 μmol·m-2·s-1,0.76 μmol·m-2·s-1 and 1.78 μmol·m-2·s-1,respectively,while those from turfgrass was 1.07 μmol·m-2·s-1,0.83 μmol·m-2·s-1 and 0.24 μmol·m-2·s-1,respectively.The variations of

关 键 词：寒潮 土壤呼吸 微生物呼吸 根系呼吸 城市片林 城市草坪 

分 类 号：S154[农业科学—土壤学]