不同生长时期极端降水事件对人工针叶林净生产力的影响--以江西省吉安市千烟洲生态试验站为例  

Effects of Extreme Precipitation Events at Different Growth Stages on Net Productivity of Artificial Coniferous Forest-A Case Study of Qianyanzhou Ecological Experimental Station in Ji’an City of Jiangxi Province

作　　者：陈晨[1] 贾畅 王晶苑[3] 唐亚坤[1,4] 陈云明[1,4] Chen Chen;Jia Chang;Wang Jingyuan;Tang Yakun;Chen Yunming(Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;Key Laboratory of Ecosystem Network Observation and Simulation,Institute of Geographic Sciences and Resources,Chinese Academy of Sciences,Beijing 100101,China;Stake Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]西北农林科技大学林学院,陕西杨凌712100 [3]中国科学院地理科学与资源研究所生态系统网络观测与模拟院重点实验室,北京100101 [4]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《水土保持通报》2020年第2期317-324,共8页Bulletin of Soil and Water Conservation

基　　金：国家重点研发计划项目“黄土丘陵沟壑区植被功能提升与山地果园管理关键技术及示范”(2016YFC0501703);国家自然科学基金项目“抚育间伐调控黄土丘陵区刺槐人工林水分养分机理研究”(41771556);陕西省水保局研发项目“秦巴山地坡面近自然水土保持关键技术集成与示范”(2017sbkj-01)。

摘　　要：[目的]研究不同生长时期极端降水事件对生态系统碳通量的影响,为准确评估江西省吉安市千烟洲人工针叶林生态系统应对极端天气的响应机制提供理论基础。[方法]对比2008年与2010年植物生长初期(4月)与生长旺盛期(6月)碳通量对环境因子(净辐射RN、温度TA、土壤含水量SWC与增强型植被指数EVI)变化的响应差异。[结果] 4月份净生态系统生产力(NEP)降低22.87%,主要是初级生产总量和生态系统呼吸分别降低17.36%[GEP, 9.56 g/(m^2·d)]和2.84%[RE,2.86 g/(m^2·d)]导致,而6月份GEP降低3.58%[7.17 g/(m^2·d)]以及RE增长12.8%[20.37 g/(m^2·d)]导致NEP降低65.77%[27.55 g/(m^2·d)]。[结论]生长季初期TA降低对RE的抑制大于土壤含水量增加的影响,而生长旺盛期土壤含水量增加则会抵消降温对呼吸的抑制,造成更大的碳损失,因此后续研究森林生态系统碳通量对极端气候响应时还需要考虑植物生长时期的影响。[Objective]The effects of extreme precipitation events on ecosystem carbon flux in different growth periods were studied,in order to provide a theoretical basis for accurately assessing the response mechanism of an artificial coniferous forest ecosystem to extreme weather at Qianyanzhou of Ji’an City,Jiangxi Province.[Methods]The response of carbon flux to changes in environmental factors(net radiation RN,temperature TA,soil water content SWC,and enhanced vegetation index EVI)in the early growth period(April)and flourishing period(June)in 2008 and 2010 were compared.[Results]The net ecosystem productivity(NEP)decreased by 22.87%in April,mainly due to a decrease of 17.36%〔GEP,9.56 g/(m^ 2·d)〕in total primary production and 2.84%〔RE,2.86 g/(m^ 2·d)〕in ecosystem respiration by 17.36%〔GEP,9.56 g/(m^ 2·d)〕.While in June,a decrease of 3.58%〔7.17 g/(m^ 2·d)〕in GEP and an increase of 12.8%〔20.37 g/(m^ 2·d)〕in RE,led to a decrease of 65.77%〔27.55 g/(m^ 2·d)〕in NEP.[Conclusion]The inhibition of RE caused by the reduction of TA at the early growing season was greater than that caused by the increase of soil moisture content,while the increase in soil moisture during the flourishing period would offset the inhibition of cooling on respiration,resulting in greater carbon loss.Therefore,the impacts of carbon flux on extreme climate should also be considered in future studies.

关 键 词：极端降水现象 亚热带人工针叶林 碳通量 环境因子 通径分析 

分 类 号：S718.5[农业科学—林学]