珠穆朗玛峰北坡高寒草甸生态系统CO_2通量日变化与月变化特征  

Diurnal and Seasonal Variations of the Carbon Dioxide over the Alpine Meadow Ecosystem on the Northern Slope of the Qomolangma

作　　者：朱志鹍[1] 马耀明[1] 李茂善[2] 仲雷[1] 

机构地区：[1]中国科学院青藏高原研究所,北京100085 [2]中国科学院寒区旱区环境与工程研究所西部气候环境与灾害实验室,甘肃兰州730000

出　　处：《高原气象》2007年第6期1300-1304,共5页Plateau Meteorology

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-231);国家重点基础研究发展规划项目(2005CB422003);国家自然科学基金项目(40520140126;40533018)共同资助

摘　　要：采用涡度相关法，对珠穆朗玛峰北坡高寒草甸生长季与非生长季（2005年5～7月、10月、n月及2006年2月、3月）的CO2通量进行了观测。分析结果表明，在生长季，CO2通量存在明显的日变化，08：00～19：00（北京时，下同）为CO2净吸收，20：00-09：00为CO2净排放。6月，CO2通量峰值出现在11：00左右为一0．61g·m^-2·h^-1；而7月，C02通量峰值出现在14：00，达到-0．86g·m^-2·h^-1。从月变化来看，5月为CO2净排放，月总量为89g·CO2·m^2，6月和7月均为CO2净吸收阶段，月吸收总量分别为70g·CO2·m^-2和104g·CO2·m^2；而1O月，植物枯黄，生态系统转为碳排放，月排放量约为50g·CO2·m^-2，与次年3月份月总量（52g·CO2·m^-2）接近，而11月份与次年2月份的月排放量接近（分别是23g·CO2·m^-2，25g·CO2·m^-2）。非生长季（2月）CO2通量日变化振幅很小，除14：00-19：00少量的CO2净排放外（0．14g·m^-2·h^-1左右），其余时间CO2接近零。Based on the open-path eddy covariance observation over an alpine meadow ecosystem during growing season（from May to July, October ＆ November in 2005 ）and non-growing season（February ＆ March in 2006） at Quzong station（30°46′N, 90°59′E, 4730 m a. s. 1） which is located on the northern side of the Qomolangma, the diurnal and seasonal variations of the carbon dioxide flux are analyzed in this paper. CO2 flux dynamics was distinct between the two seasons. During the growing season the negative CO2 （CO2 uptake）flux was observed from 08：00 to 19：00, but positive CO2 flux （net CO2 emission） from 20：00 to 09：00. In June, the maximum CO2 uptake velocity was 0.61 g·m^-2·h^-1 which appeared at 11：00. In July, this value reached 0.86 g·m^-2·h^-1 which appeared at 14：00. The total monthly influx in June and July was 70g. CO2·m^-2, 104g. CO2 · m^-2, respectively. The net CO2 flux in October （50 g · CO2 ·m^-2·h^-1） was close to that in March （52 g ·CO2· h^-1 ）in the next year. During non-growing season, the diurnal CO2 flux was close to zero during most time of the day, but showed a weak net CO2 flux from 14.00 to 19=00 （around0.14 g·m^-2·h^-1） .The net CO2 flux of November （23 g· CO2 ·m^-2·h^-1） was close to that in February（25 g ·CO2 ·m^-2·h^-1）in the next year.

关 键 词：珠穆朗玛峰北坡 高寒草甸 CO2通量 日变化 月总量 

分 类 号：P402[天文地球—大气物理学与大气环境]