植被对亚热带城市生态系统CO_2通量的影响  

Impact of vegetation on CO_2 flux of a subtropical urban ecosystem

作　　者：龚元 郭智娟 张凯迪[1,3] 徐良 魏艳艳 赵敏 GONG Yuan;GUO Zhijuan;ZHANG Kaidi;XU Liang;WEI Yanyan;ZHAO Min(Key Laboratory of Urban Ecology and Environmental Processes,Shanghai Normal University,Shanghai 200234,China;College of Life and Environmental Sciences,Shanghai Normal University,Shanghai 200234,China;Geography Department,Tourism College,Shanghai Normal University,Shanghai 200234,China;College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037,China;Research Center of Urban Ecology and Environment,Shanghai Normal University,Shanghai 200234,China)

机构地区：[1]上海师范大学城市生态与环境过程重点实验室,上海200234 [2]南京林业大学生物与环境学院,南京210037 [3]上海师范大学生命与环境科学学院,上海200234 [4]上海师范大学旅游学院地理系,上海200234 [5]上海师范大学城市生态与环境研究中心,上海200234

出　　处：《生态学报》2019年第2期530-541,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金青年基金(31100354)

摘　　要：城市是陆地生态系统的主要碳源,而城市植被是城市区域缓解人类活动所释放的二氧化碳的主要碳汇,但对城市植被对城市大气二氧化碳的影响方面的研究比较缺乏,尤其是发展中国家。发展中国家多数处于亚热带气候区,且发展中国家城市化进程较快,为推进不同生态系统类型碳循环的研究,该研究以位于中国东南部的上海市奉贤大学城为案例,研究该区域植被对亚热带城市生态系统CO_2通量的影响。使用上海市奉贤大学城的涡动相关通量观测站点所观测和记录的2016年10月1日至2017年9月30日共计12个月的通量,气象数据结合遥感数据分析了该研究区的CO_2通量动态特征及其影响因子,主要结论是:(1)整个生态系统全年CO_2通量总交换量为9664.06μmol m^(-2)a^(-1)即表现为碳源。CO_2通量增长率在2017年5月6日达到最低为-4.48μmol m^(-2)d^(-1)在2017年7月30日的CO_2通量增长率为0,在2017年8月30日达到最高为2.24μmol m^(-2)d^(-1),生长季CO_2通量交换量为2169.58μmol m^(-2)月^(-1)低于非生长季的CO_2通量交换量(7494.48μmol m^(-2)月^(-1));(2)不同风区的CO_2通量特征不同,主要表现为随着植被面积的上升CO_2通量有下降的趋势,生长季CO_2通量均值的最低值出现在西北风区为0.09μmol m^(-2)s^(-1);(3) CO_2通量与叶面积指数呈现负相关关系,即随着叶面积指数的上升CO_2通量有下降的趋势。植物的生长状况和其生理活动影响亚热带城市生态系统的碳循环过程,该研究可以为量化城市植被对大气二氧化碳的影响提供参考,同时为亚热带地区建设绿色低碳城市提供服务。Cities are the main carbon source among the terrestrial ecosystem types,and urban vegetation is an important carbon sink to mitigate carbon emissions from human activities in urban areas,but research on the influence of urban vegetation on urban atmospheric carbon dioxide is scarce,especially in developing countries. Most of the developing countries are in a subtropical climate zone,and the urbanization speed in developing countries is faster than that indeveloped countries. In order to promote the study of the carbon cycle in different ecosystem types,we studied the influence of vegetation on the CO2 fluxes of the subtropical urban ecosystem in Fengxian University city,Shanghai,China. Using the12-month flux observed and recorded by the eddy-related flux observation site in the study area and meteorological data combined with remote sensing data,the CO2 flux dynamic characteristics and its influencing factors were analyzed. The main results are the following:(1) The study area was a carbon source,and the total annual CO2 flux of the whole ecosystem was9664.06 μmol m^-2a^-1. The CO2 flux growth rate reached a minimum of-4.48 μmol m^-2d-1on May 6,2017,with a CO2 flux growth rate of 0 on July 30,2017 and a maximum of 2.24 μmol m^-2d-1on August 30,2017. The CO2 flux exchange in the growing season was lower than the CO2 flux exchange in the non-growing season;these were 2169.58 μmol m^-2月^-1and7494.48 μmol m^-2月^-1respectively;(2) Urban vegetation was a carbon sink,and its CO2 fluxes decreased with the urban vegetation area in different wind sectors. The lowest mean value of CO2 flux in the growing season appeared in the Northwest region and was 0.09 μmol m^-2s-1;(3) Leaf area index and plant biotic characteristics influence CO2 flux. There was a negative correlation between CO2 flux and leaf area index. Plant growth status and plant physiological activities affected the carbon cycling process of the subtropical urban ecosystem. This study can provide a reference for quantifying the effects of urban vegetati

关 键 词：涡动相关系统 CO2通量 植物生理 亚热带城市 遥感 

分 类 号：Q948[生物学—植物学]