利用涡动相关技术对2007年8月18日~9月12日在内蒙古羊草和大针茅草原样地上进行微气象观测， 比较了两种草原生态系统下垫面水汽、 CO2通量交换的差异， 结果表明： （1）羊草样地的气温、 地表温度和水汽压较小； 羊草和大针茅样地的地表反射率平均值分别为0.17和0.16； （2）受土壤水分胁迫控制， 羊草和大针茅样地的有效能量主要分配为感热通量， 平均波文比分别为3.70和2.69， 潜热通量在大针茅样地更大， 有随着土壤湿度持续减小而减小的趋势; （3）羊草和大针茅样地在观测期间表现为CO2的源， 日均释放率分别为0.97 g·CO2·m-2·d-1和0.43 g·CO2·m-2·d-1。受土壤水分胁迫和草地生理作用的控制， 日间羊草和大针茅样地都出现了CO2通量的衰减。
Abstract
Based on the eddy covariance measurements of Leymus chinensisand Stipa grandis steppesin Inner Mongolia from August 18 to September 12, 2007, the differences of water vapor flux and carbon flux exchange between the two kinds of grassland ecosystem surface are obtained. The main results are as follows. (1)Leymus surface had lower air temperature, surface temperature and water vapor pressure than Stipa one. The average albedos of Leymusand Stipasurfaces were separately 0.17 and 0.16. (2)Under soil water stress condition, most part of available energy dispersed in form of sensible heat flux both Leymusand Stipa sample sites. The latent heat flux of Stipa one was bigger than that of Leymus one and showed decreasing trend when soil moisture decreased. (3)During the measurements period, both Leymus and Stipa sites acted as source of carbon. The daily average values of CO2 flux were separately 1.18 g·CO2·m-2·d-1and 0.49 g·CO2·m-2·d-1. Controlled by soil water stress and physiological functionof grassland, depression of CO2 flux appeared during the daytime both the Leymusand Stipa surface.
关键词
内蒙古 /
半干旱草原 /
羊草草原 /
大针茅草原 /
水汽通量 /
CO2通量
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Key words
Inner Mongolia /
Semi-arid grassland /
Leymus chinensis ste /
Stipa grandis steppe /
Water vapor flux /
CO2 flux
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参考文献
[1]Law B E, Falge E, Gu L,et al. Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation[J]. Agricultural and Forest Meteorology, 2002, 113: 97-120
[2]王介民.陆面过程实验和地气相互作用研究\_\_从HEIFE到IMGRASS和GAME-Tibet/TIPEX[J].高原气象, 1999, 18(3): 280-294
[3]Hao Y, Wang Y, Sun X,et al. Seasonal variation in carbon exchange and its ecological analysis over Leymus chinensis steppe in Inner Mongolia[J]. Science in China (D), 2006, 49: 186-195
[4]Xue Y. The Impact of desertification in the Mongolian and the Inner Mongolian grassland on the regional climate[J]. J Climate, 1996, 9: 2173-2189
[5]吕达仁,陈佐忠,汪诗平,等.内蒙古半干旱草原气候生态相互作用问题—IMGRASS计划初步结果[J].地学前缘, 2002(a), 9(2): 307-320
[6]吕达仁,陈佐忠,陈有君,等.内蒙古半干旱草原土壤植被大气相互作用(IMGRASS)综合研究[J].地学前缘, 2002(b), 9(2): 295-306
[7]吕达仁,陈佐忠,陈家宜,等.内蒙古半干旱草原土壤-植被-大气相互作用综合研究[J].气象学报, 2005, 63(5): 571-593
[8]Fu Y, Yu G, Sun X, et al. Depression of net ecosystem CO2 exchange in semi\|arid Leymus chinensissteppe and alpine shrub[J]. Agricultural and Forest Meteor, 2006, 137: 234-244
[9]Hao Y, Wang Y, Huang X, et al. Seasonal and interannual variation in water vapor and energy exchange over a typical steppe in Inner Mongolia, China[J]. Agricultural and Forest Meteorology, 2007, 146: 57-69
[10]http://eco.ibcas.ac.cn/station/imgers/jianjie.htm
[11]Schotanus P, F TM Nieuwstadt, H A R Bruin. Temperature measurement with a sonic anemometer and its application to heat and moisture fluxes[J]. Boundary\|Layer Meteor, 1983, 26: 81-93
[12]Moore C J. Frequency response corrections for eddy correlation systems[J]. Boundary-Layer Meteor, 1986, 27: 17-35
[13]Webb E K, G I Pearman, R Leuning. Correction of flux measurements for density effects due to heat and water vapour transfer[J]. Quart J Roy Meteor Soc, 1980, 106: 85-100
[14]刘辉志,洪钟祥,张宏升,等.内蒙古奈曼流动沙丘下垫面湍流输送特征初步研究[J].大气科学, 2003, 27(3): 389-398
[15]马伟强,马耀明,胡泽勇,等.藏北高原地面辐射收支的初步分析[J].高原气象, 2004, 23(3): 348-352
[16]冯健武,刘辉志,邹捍,等.珠峰绒布河谷近地面层气象要素及湍流通量变化[J].高原气象, 2007, 26(6): 1244-1253
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