| Other Abstract | Based on the eddy covariance measurement from September 2005 to September 2006 over the grassland at Namco Monitoring and Research Station for Multi-sphere Interactions, from May 2005 to March 2006 at Quzong site of Atmospheric and Environmental Comprehensive Observation and Research Station and from May to August in 2007 at Integrated observation and research Station for alpine environment in South-East Tibet, the diurnal course and seasonal variance of CO2 flux is analyzed contradistinctively. Some significative conclusions are showed as follow: 1. Compared the diurnal variation of CO2 flux of different grassland ecosystem at different measurement stations of Tibetan Plateau, we find that the maximum value of CO2 uptake of grassland ecosystem in Linzhi is higher than that in Quzong. The maximum value of CO2 uptake of grassland ecosystem is the lowest. 2. The precipitation was sufficient in the growing season at Linzhi station. Therefore, the CO2 uptake velocity of grassland ecosystem is high in daytime and the efflux was high in nighttime as well. This mainly resulted from the high air and soil temperature and soil humidity at night. The ecosystem respiration was more active than that in other stations, which resulted that the monthly total CO2 uptake was not the maximum. In contrast, the lower nighttime temperature in the grassland of growing season at Namco station constrained the respiration. Consequently, it made the grassland ecosystem at Namco station likely to be a sink of carbon. As a result, the monthly total CO2 uptake in August at Namco was higher than that at Linzhi station. 3. The correlation analysis showed that solar radiation was the major environmental factor determining the CO2 flux in the daytime during the growing season. The photosynthesis also had a close relationship with LAI (Leaf Area Index). Compared with the grassland ecosystem LAI of other areas in the world, the LAI was smaller. When growing season began, the plant turned green in May as the temperature rising. In the daytime as the temperature rising and the radiation getting intense, the photosynthesis and respiration were both active. The maximum CO2 influx appeared before 12:00 . |
| Table of Contents | 中文摘要 ........................................................................................................................................ I
英文摘要 ....................................................................................................................................... II
目 录 ..................................................................................................................................... IV
论文中表格 .................................................................................................................................. VI
论文中插图 ................................................................................................................................ VII
第一章 绪论 ............................................................................................................................. 1
1.1 陆地生态系统碳循环研究概述 ....................................................................................... 1
1.2 草地生态系统碳循环的研究进展 .......................................................................... 3
1.2.1 草地生态系统概况 ........................................................................................... 3
1.2.2 草地生态系统在碳循环中的作用 .................................................................. 3
1.2.3 我国草地生态系统CO2 通量观测与研究 ..................................................... 4
1.3 全球通量网FLUXNET ......................................................................................... 5
1.4 涡度相关法概述 ..................................................................................................... 7
1.4.1 涡度相关法发展概况 ....................................................................................... 7
1.4.2 涡度相关法的基本原理 ................................................................................... 8
1.4.3 影响涡度相关法观测CO2 通量的效应 ........................................................ 10
1.4.4 涡度相关观测的通量数据的校正方法 ......................................................... 11
1.5 本文的研究内容及结构 ........................................................................................ 14
1.5.1 研究目的及意义 ............................................................................................. 14
1.5.2 研究内容 ......................................................................................................... 14
1.5.3 论文结构 ......................................................................................................... 15
第二章 观测场地及观测仪器 ........................................................................... 16
2.1 观测站点介绍 ....................................................................................................... 16
2.2 开路涡度相关系统介绍 ....................................................................................... 18
2.3 开路涡度相关系统与常规气象系统的对比分析 ............................................... 20
第三章 各观测站气象要素的变化 .................................................................. 22
3.1 纳木错站近地层气象要素的变化 ....................................................................... 22
3.2 曲宗站近地层气象要素的变化 ........................................................................... 23
3.3 林芝站近地层气象要素的变化 ........................................................................... 25
第四章 青藏高原不同下垫面CO2 通量变化特征分析 ............................ 27
4.1 纳木错站草地生态系统CO2 通量变化特征 ...................................................... 27
4.2 曲宗站草地生态系统CO2 通量变化特征 .......................................................... 30
4.3 林芝站草地生态系统能量和CO2 通量变化特征 .............................................. 33
4.3.1 近地层能量收支 .............................................................................................. 33
4.3.2 土壤温度与土壤体积含水量 .......................................................................... 34
4.3.3 CO2 通量的变化特征 ....................................................................................... 35
第五章 结论与展望 .............................................................................................. 38
5.1 主要结论 ............................................................................................................... 38
5.2 存在的问题及展望 ................................................................................................ 39
参考文献 ................................................................................................................... 41
个人简介 ................................................................................................................... 46
攻读硕士学位期间参加的课题 ......................................................................... 46
攻读硕士学位期间发表的论文 ......................................................................... 46
致谢 ............................................................................................................................ 47
论文中表格
表1-1 北美与欧亚大陆地-气间净碳通量的分布（Schimel et al.，2001）
Table 1-1 Estimated distribution of net land-atmosphere carbon fluxes between
North America and Eurasia（Schimel et al.，2001）
表1-2 中国通量网站点信息(引自：www.ChinaFLUX.org)
Table 1-2. The information of ChinaFLUX sites（from：www.ChinaFLUX.org）
表2-1 观测站点的主要信息
Table 2-1 Information of the measurement sites
表4-1 曲宗地区高寒草甸生态系统各月CO2 总量
Table 4-1 Monthly net CO2 flux in the alpine meadow ecosystem
表4-2 7 月份青藏高原不同地区草地生态系统CO2 吸收量
Table 4-2 Monthly net CO2 flux in the grassland ecosystem of various region on
the Tibetan Plateau
表4-3 纳木错、曲宗和林芝地区草地生长季CO2 月总量（单位：g m-2）
Table 4-3 The monthly net CO2 flux of growing season in Namco ,Quzong and
Linzhi (unit: g m-2)
论文中插图
图1-1 生态系统中的碳循环（李博等，2000）
Fig.1-1 Carbon Cycling in ecosystem ( Li et al., 2000)
图1-2 全球通量观测网（左）与中国通量观测网（右(www.daac.ornl.gov/FLUXNET）
Fig 1-2 FLUXNET (left ) and ChinaFLUX (right)
(from: www.daac.ornl.gov/FLUXNET)
图1-3 植被表层上的笛卡尔坐标系控制体积（引自：Leuning R. 2004.）
Fig1-3. Cartesian control volume placed over a vegetated surface（from：
Leuning R. 2004.）
图1-4 坐标轴旋转角度α、β、γ 的定义.原坐标轴为x，y，z，最终坐标轴x’，y’，
z’，中间过程坐标轴为xI，yI，zI.（引自：Wilczak et al.，2001）
Fig 1-4 Definitions of the tilt angles α，β，γ for the yxz convention. The original
axes are x, y, z, the final axes are x’, y’, z’, and intermediate axes are xI, yI,
zI.( from:Wilczak et al.，2001)
图1-5 坐标旋转和平面拟合示意图（引自：朱治林等，2004）
Fig 1-5 Coordinate rotation and planar fit (from: Zhu et al.，2004)
图2-1 曲宗观测站仪器及其场地环境
Fig.2-1 the measurement instruments and surroundings of Quzong site
图2-2 纳木错站观测仪器及观测站地环境
Fig.2-2 the measurement instruments and surroundings of Namco station
图2-3 林芝站观测仪器及观测场地
Fig.2-3 the measurement instruments and surroundings of Linzhi site
图2-4 开路涡度相关观测系统示意图
Fig 2-4 Open-path eddy covariance system
图2-5 湍流数据的处理流程（，，分别表示三维风分量，T，C，q 表示温度、
CO2 浓度、比湿；一撇表示各物理量的脉动量；Fc、H、LE 分别表示CO2、
感热和潜热通量）
Fig 2-5 the turbulent data processing（，， represents 3‐D wind velocity; T，
C，q represents temperature ,CO2 density and specific humidity respectively; Fc、
H、 LE represents CO2 flux, sensible heat flux and latent heat flux respectively）
图2-6 开路涡度相关系统测定的温度、空气绝对湿度与空气温/湿度探头观测的
温度、空气绝对湿度的关系(a、b 为曲宗2005 年7 月，c、d 为纳木错2006
年7 月上旬)
Fig 2-6 Relationship between the air temperature , absolute humidity measured
by OPEC and HMP45C（a & b , c & d represents Quzong Jul 2005 and Namco
Jul 2006 respectively）
图2-7 开路涡度相关系统与常规气象系统测定的温度与风速的关系
（林芝站，2007 年7 月）
Fig.2-7 Relationship between the air temperature and wind speed measured by
OPEC and HMP45C(Linzhi, Jul 2007)
图3-1 纳木错站近地层气压、气温、湿度的逐日变化（30min 间隔）
Fig 3-1 Annual course of the air pressure, temperature and absolute humidity of
the surface-layer at Nam co station (30min interval)
图3-2 曲宗站近地层气压、气温和空气湿度的年变化（30min 间隔）
Fig 3-2 Annual course of the air pressure, temperature and absolute humidity of
the surface-layer at QUZONG station (30min interval)
图3-3 2007 年5 月~8 月林芝站草地生长季气压、温度和空气湿度的逐日变化
（10min 间隔）
Fig.3-3 The seasonal course of pressure, temperature and absolute humidity
(1.3m) over grassland from May to August (10min average)
图3-4 2007 年5 月~8 月林芝站降雨量与近地层风速的逐日变化（10min 间隔）
Fig.3-4 The daily total rainfall and seasonal course of wind speed (1.3m) over
grassland from May to August (10min average)
图4-1 纳木错地区草地生态系统生长季CO2 通量日变化
Fig. 4-1 Diurnal variation of CO2 flux during growing season at Namco site
图4-2 纳木错站草地生长季与非生长季节CO2 通量日变化动态
Fig.4-2 Diurnal course of monthly averaged CO2 flux during the growing and non
growing season
图4-3 纳木错站草地生长季（8 月）CO2 通量与净辐射
Fig.4-3 Relationship between CO2 flux and net radiation
图4-4 曲宗站高寒草甸生长季CO2 通量日变化特征（缺少8、9 月资料）
Fig.4-4 Diurnal variation of monthly averaged CO2 flux during the growing
season in the alpine meadow ecosystem on the Quzong site (there is lack of the
data of August and September)
图4-5 曲宗站高寒草甸生长季（7 月）与非生长季（2 月）CO2 通量的日变化特
征
Fig 4-5 Diurnal variation of monthly averaged CO2 flux during the growing
season (July) and non-growing season (February) in the alpine meadow
ecosystem on the Quzong site
图4-6 曲宗站高寒草甸生长季(7 月)每小时平均CO2 通量与平均温度
Fig.4-6 The Diurnal variation of averaged CO2 flux and averaged air
temperature during the growing season (July) in a alpine meadow ecosystem on
the Quzongsite
图4-7 曲宗站生长季7 月份CO2 通量与净辐射
Fig 4-7 Relationship between CO2 flux and net radiation
图4-8 林芝站近地层能量收支月平均的日变化（单位：W m-2）
Fig. 4-8 The monthly-average diurnal variation of the energy budget in the
surface layer (unit: W m-2) at Linzhi
图4-9 2007 年5 月~8 月（8 月25 日）林芝站4cm、10cm、20cm 土壤温度日均
值的变化
Fig.4-9 The seasonal course of daily average 4-cm, 10-cm, and 20-cm soil
temperature from May to August (Aug. 25th)
图4-10 2007 年5 月~8 月林芝站土壤体积含水量（Sw）与降雨量（P）的变化
（10min 间隔）
Fig. 4-10 The seasonal course of daily average soil volumetric water content (Sw)
and daily rainfall (P) for the surface layer of the grassland from May to August
(10min average)
图4-11 林芝站草地生长季CO2 通量月平均的日变化
Fig.4-11 The monthly-average diurnal variation of the CO2 flux in the growing
season
图4-12 林芝站草地生长季白天通量与净辐射
Fig.4-12 Relationship between CO2 flux and net radiation during the growing
season |
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