Temporal and spatial variations of stem CO_(2) efflux of three species in subtropical China

作     者：Qingpeng Yang Ming Xu Yonggang Chi Yunpu Zheng Ruichang Shen Peixue Li Huitang Dai 

作者机构：Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences11ADatun RoadChaoyang DistrictBeijing 100101China Graduate School of Chinese Academy of Sciences19A YuquanluBeijing 100039China Jigongshan National Nature ReserveXinyang 464133China 

出 版 物：《Journal of Plant Ecology》 (植物生态学报（英文版）)

年 卷 期：2012年第5卷第2期

页      面：229-237页

核心收录：

学科分类：0710[理学-生物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0401[教育学-教育学] 04[教育学] 0901[农学-作物学] 0902[农学-园艺学] 0713[理学-生态学] 

基　　金：Forestry Commonwealth Research Special Foundation of State Forestry Administration(200804005) National Key Research and Development Program(2010CB833500) Hundred Talents Program of Chinese Academy of Sciences to M.Xu 

主　　题：stem respiration apparent temperature sensitivity Q_(10) diurnal and seasonal variation spatial variation 

摘      要：Aims Although stem CO_(2) efflux is critical to ecosystem carbon and energy balance and its feedback to future climate change,little information is available on stem CO_(2) efflux and its responses to temperature,especially in subtropical *** study aims to(i)evaluate the temporal and spatial variations of stem CO_(2) efflux of three species,including oak(Quercus acutissima Carr.),masson pine(Pinus massoniana Lamb.)and loblolly pine(Pinus taeda Linn.)in subtropical China and(ii)analyze the temperature sensitivity of stem CO_(2) efflux in the three species based on 2-year field *** We measured stem CO_(2) efflux and stem temperature(at 3 cm depth)of the three species using the horizontally oriented soil chamber technique from September 2008 to August *** also conducted a 24-h measurement to examine the diurnal variation of stem CO_(2) efflux in three consecutive days in April *** findings The temporal dynamics of stem CO_(2) efflux followed the change of the stem temperature in a 3-cm depth with a bell-shaped curve in the three *** temperature explained 77–85%of the seasonal variations of stem CO_(2) efflux over the entire study period in the three *** temperature sensitivity(Q_(10))of stem CO_(2) efflux was obviously different among the three species with higher Q10 value found in oak(2.24)and lower values in the coniferous species(1.76 and 1.63).Our results also showed that the Q10 values of stem CO_(2) efflux in all the three species were lower in the growing season than that in the non-growing season,indicating that the growth and maintenance respiration had different temperature ***,we found that the temperature-normalized stem CO_(2) efflux(R_(10))changed greatly between the growing and non-growing seasons in oak and masson pine,but not in loblolly ***,we also found that in the non-growing season,the principal factor responsible for the spatial variation of stem CO_(2) efflux am