全 文 :植物生态学报 2015, 39 (7): 661–673 doi: 10.17521/cjpe.2015.0063
Chinese Journal of Plant Ecology http://www.plant-ecology.com
——————————————————
收稿日期Received: 2015-02-04 接受日期Accepted: 2015-06-07
* 通讯作者Author for correspondence (E-mail: gxhan@yic.ac.cn)
阴天和晴天对黄河三角洲芦苇湿地净生态系统CO2
交换的影响
初小静1,2 韩广轩1* 邢庆会1,2 于君宝1 吴立新3 刘海防3 王光美1 毛培利1
1中国科学院烟台海岸带研究所, 中国科学院海岸带环境过程与生态修复重点实验室, 山东烟台 264003; 2中国科学院大学, 北京 100049; 3黄河三角
洲国家级自然保护区管理局, 山东东营 257091
摘 要 云量以及大气气溶胶含量变化引起的阴天和晴天会对局地的微气候环境产生综合效应, 影响地面接收的太阳辐射
强度, 同时引起环境因子的变化, 最终对净生态系统CO2交换(NEE)产生影响。该文通过涡度相关系统以及微气象梯度观测系
统, 对黄河三角洲芦苇(Phragmites australis)湿地NEE以及环境要素进行了观测。在自然条件下选择12对相邻阴天和晴天数据,
在生物要素(生物量、叶面积指数)、土壤水分以及养分特征保持不变的前提下, 揭示了阴天和晴天变化对湿地生态系统NEE
的光响应和温度响应的影响。结果表明: 12对阴天和晴天生态系统NEE的日平均动态均呈“U”型曲线, 但阴天NEE的变幅较
小。晴天条件下湿地生态系统NEE的日均值显著高于阴天(p < 0.01)。阴天和晴天湿地生态系统NEE与光合有效辐射(PAR)之
间均呈直角双曲线关系, 但晴天条件下, 最大光合速率(Amax)显著大于阴天(p < 0.01), 同时白天生态系统呼吸(Reco,daytime)也显
著大于阴天(p < 0.01)。不论阴天还是晴天, Reco,daytime与气温均呈显著的指数关系。晴天湿地生态系统呼吸的温度敏感系数Q10
(5.5)远大于阴天(1.9)。阴天和晴天昼间PAR差值以及气温差值对NEE差值的协同影响达到63%。
关键词 阴天, 晴天, 净生态系统CO2交换, 白天生态系统呼吸, 光响应, 温度响应
引用格式: 初小静, 韩广轩, 邢庆会, 于君宝, 吴立新, 刘海防, 王光美, 毛培利 (2015). 阴天和晴天对黄河三角洲芦苇湿地净生态系统CO2交换的影
响. 植物生态学报, 39, 661–673. doi: 10.17521/cjpe.2015.0063
Net ecosystem exchange of CO2 on sunny and cloudy days over a reed wetland in the Yellow
River Delta, China
CHU Xiao-Jing1,2, HAN Guang-Xuan1*, XING Qing-Hui1,2, YU Jun-Bao1, WU Li-Xin3, LIU Hai-Fang3, WANG
Guang-Mei1, and MAO Pei-Li1
1Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Chinese Academy of Sciences, Yantai Institute of Coastal Zone Research,
Chinese Academy of Sciences, Yantai, Shandong 264003, China; 2University of Chinese Academy of Sciences, Beijing 100049, China; and 3Administration
Bureau of the Yellow River Delta National Nature Reserve, Dongying, Shandong 257091, China
Abstract
Aims Clouds and aerosols change the radiation level on the land surface and indirectly alter the microclimate.
Shifts in sunny and cloudy days, for example, would affect the net ecosystem exchange of CO2 (NEE) between
land surface and the atmosphere. Our objective was to analyze the influence of shifts in sunny and cloudy days on
NEE, its responses to light and temperature in a reed (Phragmites australis) wetland in the Yellow River Delta,
China.
Methods Using the eddy covariance technique, we measured the temporal changes in NEE during the growing
season over the reed wetland. We selected 12 paired-days during the measurement period following two criteria:
(1) the two paired days are adjacent, with one sunny day and another cloudy day; (2) no rain event during the two
days. We assumed that: (1) live biomass and leaf area index (LAI) are the same during any paired-days; (2) soil
moisture has no significant difference between the two adjacent days. With these criteria, we expected that radia-
tion condition exerted the major control on NEE.
Important findings Diurnal change of NEE showed a distinct U-shaped pattern on both sunny and cloudy days,
but with substantial variation in its amplitude. During the daytime, NEE on sunny days was significantly higher (p
< 0.01) than that on the cloudy days (n = 12). The daytime NEE response to photosynthetically active radiation
(PAR) was modeled with the rectangular hyperbolic function (Eq. (1)) for both sunny and cloudy days. There
662 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
appeared a significant reduction (p < 0.01) in light-saturated NEE (Amax) on cloudy days compared to the sunny
days. Similarly, there was a significant decrease (p < 0.01) in daytime ecosystem respiration (Reco,daytime) on cloudy
days as compared to that of the sunny day although there existed significant exponential relationships between
Reco,daytime and air temperature on both sunny and cloudy days. In addition, the temperature sensitivity of ecosys-
tem respiration (Q10) on cloudy days (1.9) was significantly lower than that of sunny days (5.5). Stepwise multiple
regression analyses suggested that PAR and T explained 63% of the changes in NEE between sunny and cloudy
days. By taking advantage of the natural shift of sunny and cloudy days without disturbance to the plant-soil sys-
tem, our results indicated that cloud cover significantly reduced the absorption capacity of CO2 in the wetland.
Thus, it is necessary to take into account the shits between sunny and cloudy days on NEE when predicting the
ecosystem responses to future climate in the wetland.
Key words sunny day, cloudy day, net ecosystem CO2 exchange (NEE), daytime ecosystem respiration
(Reco,daytime), light response, temperature response
Citation: Chu XJ, Han GX, Xing QH, Yu JB, Wu LX, Liu HF, Wang GM, Mao PL (2015). Net ecosystem exchange of CO2 on sunny
and cloudy days over a reed wetland in the Yellow River Delta, China. Chinese Journal of Plant Ecology, 39, 661–673. doi:
10.17521/cjpe. 2015.0063
近年来, 大气污染、气溶胶粒子增加等环境问
题日益严重, 云层和大气气溶胶含量的变化给地面
接收的直接辐射和散射辐射带来很大影响(Niyogi
et al., 2004; Bar-Or et al., 2010; 马金玉等, 2011)。我
国华北地区大气环境由于受到西北地区沙尘的影
响, 大量滞留在大气中的沙尘成为对流层气溶胶的
主要成分, 影响地-气系统辐射能收支, 从而影响区
域的气候及生态环境(Min, 2005; 贾漩等, 2010)。研
究表明: 近50年来, 地面太阳总辐射从减少到增加
(齐月等, 2014)。而云作为一种天气现象会对局地的
微气候环境产生综合效应, 当天空有云层出现时,
地面接收的太阳辐射强度及散射辐射与直射辐射的
比例会发生变化, 引起生态系统光能与热能的变化,
植被的光合与呼吸作用发生变化, 最终生态系统与
大气间的净CO2交换也会受到影响 (Letts et al.,
2005; Urban et al., 2007)。
已有研究表明, 阴天和晴天所引起的辐射差异
影响着陆地生态系统的交换过程和碳吸收能力
(Roderick et al., 2001; Still et al., 2009)。但由于研究
方法、地域环境条件以及不同植被类型的差异, 研
究结论存在较大差异(Gu et al., 1999, 2002; Alton et
al., 2007; Urban et al., 2007)。例如, 中国渭北刺槐
(Robinia pseudoacacia)生长初期和旺盛期晴天条件
下森林日均固碳量比阴天高8%–16% (郑元等 ,
2011)。中国西北玉米(Zea mays)农田生态系统阴天
条件下净生态系统CO2交换(NEE)的增长速率却高
于晴天, 且生态系统总初级生产力(GPP)最大值出
现于阴天(Zhang et al., 2011)。对中国西北草地(Bai
et al., 2012)和不同温带森林类型(Zhang et al., 2010)
的研究也得出类似结论。另外, 也有研究发现加拿
大常绿灌木(Letts et al., 2005)和西藏高寒草甸(范玉
枝等, 2009)生态系统CO2交换不受阴天和晴天天气
条件影响。
黄河口近海与海岸湿地是暖温带增长速度最快
和最具代表性的新生近海与海岸湿地, 具有海陆过
渡性、原生性和脆弱性的特点(布仁仓等, 1999; 崔
树强, 2002)。受水沙量变化、陆地和河流淡水径流、
咸水海流多重影响以及人类活动的干扰, 黄河三角
洲湿地生态系统CO2交换存在着极大的复杂性和不
确定性(Sasaki et al., 2009;Han et al., 2014a, 2014b;
邢庆会等, 2014)。研究表明黄河三角洲芦苇湿地生
长季NEE占全年的80%以上, 且碳吸收集中在植物
生长旺盛期(7–9月)(杨利琼等 , 2013; Han et al.,
2014a, 2014b)。而这一时期正值黄河三角洲雨季,
其云雨状况影响太阳辐射, 进而影响湿地生态系统
的碳吸收功能。在以往的研究中, 温度、水分、太
阳辐射等环境因子, 生物量、叶面积等生物因子以
及地下水位、地表水深等水文要素对湿地生态系统
NEE的影响机制受到研究者的极大关注(牟长城等,
2009; Zhao et al., 2010; Han et al., 2013; 邢庆会等,
2014)。目前, 有关阴天和晴天条件对生态系统碳交
换影响的研究主要集中在森林生态系统(Liu et al.,
2006; Zhang et al., 2010; 周丽艳等, 2010; Jiang et
al., 2011; Zhao et al., 2011; 刘佳等, 2014)和草原生
态系统(Gu et al., 2003; 范玉枝等, 2009)。阴天和晴
天状况引起的太阳辐射变化对湿地生态系统NEE和
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 663
doi: 10.17521/cjpe.2015.0063
碳汇功能究竟产生怎样的影响目前尚不清楚。
本文基于2013年黄河三角洲芦苇湿地生长季节
中的12对阴天和晴天数据, 对比分析阴天和晴天条
件下湿地生态系统CO2交换动态及其环境控制机制,
以期阐明以下3个科学问题: (1)阴天和晴天对湿地
生态系统NEE日动态变化的影响; (2)阴天和晴天对
湿地生态系统NEE光响应和温度响应的影响; (3)阴
天和晴天对湿地生态系统碳收支功能的影响。通过
分析阴天和晴天太阳辐射变化对湿地生态系统CO2
交换的影响, 揭示黄河三角洲地区芦苇湿地生态系
统CO2源/汇功能及其影响机制, 并为预测未来随云
雨天变化或大气组成及气溶胶含量变化对湿地生态
系统碳收支的影响提供数据支持和理论依据。
1 材料和方法
1.1 研究地概况
研究地点位于山东省东营市垦利县的中国科学
院黄河三角洲滨海湿地生态试验站 (37.75° N,
118.98° E)。该区域属于温带半湿润大陆性季风气
候, 光照充足, 四季分明, 雨热同期。年平均气温
12.9 ℃, 最高气温41.9 ℃, 最低气温–23.3 ℃, 年
降水量530–630 mm, 其中70%的降水量集中在5–9
月, 年内分配不均, 年蒸发量为1 900–2 400 mm。该
地区地势平坦, 植物生长茂盛, 土壤质地以轻壤土
和中壤土为主, 土壤类型以潮土和盐碱土为主。试
验站植被类型以湿地植被为主 , 优势种为芦苇
(Phragmites australis)、盐地碱蓬(Suaeda salsa)、柽
柳(Tamarix chinensis)和白茅(Imperata cylindrica)。
植被覆盖度为70%–90%。涡度相关系统设在地势平
坦、植物生长茂盛的芦苇湿地中央部, 在降水集中
的8–10月, 地面有较多积水。芦苇通常在4月中旬萌
动, 在5月中旬处于展叶盛期, 8月中旬开始抽穗, 9
月中旬开花, 10月份开始进入枯黄期, 10月底芦苇大
多枯萎, 植被高度在1.0–1.8 m。
1.2 涡度和环境要素测定
通量数据运用开路式涡度相关设备与常规气象
观测仪器进行长期定位观测。涡度相关系统包括三
维超声风速仪(CSAT-3, Campbell Scientific, Logan,
USA)和开路红外CO2/H2O分析仪(IRGA, LI-7500,
LI-COR, Lincoln, USA), 架设于距地表3 m处, 原始
数据采样频率为10 Hz。微气象观测系统包括2 m高
度的风向和风速(034B, Campbell Scientific, Logan,
USA) 、 空 气 温 度 (HMP45C, Vaisala, Helsinki,
Finland)、净辐射 (CNR4, Kipp & Zonen, Delft,
Netherlands)和降水量(TE525MM, Texas Electronics,
Dallas, USA)。土壤因子监测主要包括: 5、10、20、
30、50 cm深处的土壤温度(109SS, Campbell Scien-
tific, Logan, USA)和10、20、40、60、80、100 cm
深处的土壤含水量(EnviroSMART SDI-12, Enviro-
Scan, Lancaster, USA)。所有数据通过数据采集器
(CR1000, Campbell Scientific, Logan, USA)在线采
集, 并按30 min计算平均值进行存储。NEE数据为负
值表示生态系统吸收CO2, 即碳汇; NEE数据为正值
表示生态系统释放CO2, 即碳源。
1.3 通量数据处理
在野外通量观测中, 由于仪器响应、下垫面的
起伏、天气状况、大气稳定度及供电系统故障等因
素 , 会产生异常数据及数据的丢失 (Falge et al.,
2001)。在对原始通量数据进行分析之前, 需先进行
数据的预处理: 坐标旋转、野点去除、WPL校正、
夜间通量校正等。分析数据时进行以下处理: 1)去除
所有降水时段对应的数据; 2)去除生长季|NEE| > 1
μmol CO2·m–2·s–1的数据。
白天缺失的NEE数据(净辐射> 20 W·m–2), 采用
Michaelis-Menten模型(Ruimy et al., 1995)进行插补。
max
eco,daytime
max
A PARNEE R
A PAR
× ×= − + ×
α
α
(1)
式中, Reco,daytime为白天生态系统呼吸(daytime eco-
system respiration, μmol CO2·m–2·s–1), α为表观量子
产量(apparent quantum yield, μmol CO2·μmol–1), Amax
为最大光合速率(maximum photosynthesis rate, μmol
CO2·m–2·s–1)。NEE为直接从涡度相关仪器测定的
CO2通量数据。
夜间(净辐射< 20 W·m–2)缺失的数据采用(1)式,
利用夜间土壤温度 (Ts)与夜间通量值 (Reco,nighttime,
μmol CO2·m–2·s–1)的指数关系插补(Lloyd & Taylor,
1994)。
eco,nighttime exp( )R a bT= (2)
式中 , Reco,nighttime为夜晚生态系统呼吸 (μmol
CO2·m–2·s–1), T为空气温度或土壤温度(℃), a为参考
温度下湿地生态系统呼吸速率(μmol CO2·m–2·s–1), b
为温度反应系数。
1.4 数据筛选
基于2013年黄河三角洲芦苇湿地生长季的涡度
664 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
相关法碳通量和微气象数据, 我们选择相邻的阴天
和晴天数据, 选择标准为: (1)以15天为周期, 做出
光合有效辐射(PAR)与降水量(PPT)随时间变化的日
变化曲线, 并去除降雨天(PPT > 0.1 mm)数据; (2)
从剔除后的数据中找出白天PAR日变化表现为光滑
且对称单峰曲线的, 确定为晴天; 从确定出的晴天
找出相邻PAR日变化表现为曲折多峰的, 确定为阴
天。基于以上两条标准, 我们共选取了12对阴天和
晴天数据(图1)。由于每对数据是相邻的两天, 且没
有降水发生, 因此我们可以假定每对阴天和晴天内
图1 黄河三角洲湿地生态系统2013年生长季12对阴天和晴天的净生态系统CO2交换(NEE)与光合有效辐射(PAR)的日动态。黑
线代表晴天PAR, 灰线代表阴天PAR。
Fig. 1 Diurnal changes in net ecosystem exchange of CO2 (NEE) and photosynthetically active radiation (PAR) on the 12
paired-days (i.e., a sunny day and an adjacent cloudy day) during the 2013 growing season in the Yellow River Delta wetland. Black
and grey solid lines represent PAR on sunny and cloudy days, respectively.
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 665
doi: 10.17521/cjpe.2015.0063
生物要素(生物量、叶面积指数、盖度)、土壤湿度
以及土壤养分特征在两天内变化不大。在此前提下,
阴天和晴天引起的太阳辐射变化可能是影响湿地生
态系统CO2交换的主导因子。
1.5 数据分析
白天生态系统呼吸的温度响应主要通过以下
指数模型进行拟合:
eco,daytime exp( )R a bT= (3)
式 中 , Reco,daytime 为 白 天 生 态 系 统 呼 吸 (μmol
CO2·m–2·s–1), 由(1)式推出; T为空气温度(℃), a为参
考温度下湿地生态系统呼吸速率(μmol CO2·m–2·s–1),
b为温度反应系数。
白天生态系统呼吸的温度敏感性系数Q10基于
以下公式进行计算:
10 exp(10 )Q b= (4)
用单因素方差分析法分析阴天和晴天条件下环
境因子(PAR、T)以及阴天和晴天NEE平均值的差异
性。运用非线性拟合方法分析阴天和晴天白天NEE
与光合有效辐射(PAR)的直角双曲线关系(方程(1));
用指数模型分别拟合Reco,daytime与T的关系(方程(3))
以及生态系统白天温度敏感性系数Q10 (方程(4));
对光响应参数Amax、α以及Reco,daytime, 温度反应系数a
与b进行方差分析。通过多元回归分析PAR与T对
NEE以及Reco,daytime的协同影响作用。所有数据分析
均基于统计分析软件SPSS 16.0完成, 相关的图形均
基于SigmaPlot 11.0完成。
2 结果
2.1 阴天和晴天NEE日动态变化对比
图1为黄河三角洲湿地生态系统2013年生长季
(4–10月) 12对相邻阴天和晴天的PAR与NEE日动
态。晴天, PAR整体表现为光滑的单峰对称分布, 日
出后 , PAR逐渐增强 , 在正午前后达到最大
(1 500–2 000 μmol·m–2·s–1), 之后逐渐减弱, 至日落
后PAR又转为0; 阴天, PAR变化曲折, 通常有多个峰
值, 整体波动性相对晴天较小(图1, 图2B)。阴天和
晴天条件下, NEE日变化均呈现“U”型曲线, 表现为
白天吸收, 晚上释放。但阴天条件下, 白天的NEE
波动均小于晴天, 说明白天碳吸收能力小于晴天
(图1, 图2A)。
为比较阴天和晴天NEE随PAR及气温的变化规
律, 我们将阴天和晴天NEE、PAR和T按每天从0:00
图2 2013年黄河三角洲湿地生长季阴天和晴天净生态系统
CO2交换(NEE)、光合有效辐射(PAR)与气温(T)的平均日动态
(平均值±标准误差)。***, p < 0.001。
Fig. 2 Average diurnal variations of net ecosystem exchange
of CO2 (NEE), photosynthetically active radiation (PAR) and air
temperature (T) on sunny days and cloudy days during the 2013
growing season in the Yellow River Delta. Bars represent stan-
dard errors of the means of 12 sunny days and 12 adjacent
cloudy days (mean ± SE). ***, p < 0.001.
到23:30每0.5 h进行平均, 得到生长季阴天和晴天
NEE、PAR和T的日平均变化特征曲线(图2)。将阴天
和晴天昼间NEE、PAR和T在日进程中各实测点的观
测值分别取平均发现, 晴天NEE (– (7.7 ± 1.99)
μmol CO2·m–2·s–1)显著大于阴天(– (2.57 ± 0.57)
μmol CO2·m–2·s–1), 对环境因子的方差分析发现, 晴
天PAR ((1001.1 ± 28.3) μmol·m–2·s–1)显著大于阴天
666 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
((472.67 ± 11.62) μmol·m–2·s–1), 同时晴天气温T
((23.56 ± 2.62) ℃)也显著大于阴天((21.26 ± 2.34)
℃)。
2.2 阴天和晴天条件下白天NEE对PAR的响应
采用Michaelis-Menten方程拟合发现, 晴天拟
合参数Amax、α和Reco均于8月达到最大值, 分别为
38.65 μmol CO2·m–2·s–1、0.13 μmol CO2·μmol–1和
24.19 μmol CO2·m–2·s–1, 阴天Amax、α和Reco均在7月
达到最大值, 分别为28.07 μmol CO2·m–2·s–1、0.065
μmol CO2·μmol–1和10.79 μmol CO2·m–2·s–1。t检验发
现 , 晴天条件下 , Amax ((28.01 ± 2.91) μmol
CO2·m–2·s–1)显著大于阴天 ((19.63 ± 1.33) μmol
CO2·m–2·s–1), 同时 Reco,daytime ((7.19 ± 0.67) μmol
CO2·m–2·s–1)也显著大于阴天 ((5.75 ± 0.39) μmol
CO2·m–2·s–1), 但α间差异不显著(p > 0.05)。
在整个生长季中 , 阴天和晴天条件下NEE与
PAR均呈直角双曲线关系, 随PAR的增加NEE呈负
向增加趋势 (图 3)。在 PAR强度低于 400 μmol
CO2·m–2·s–1时, 阴天和晴天NEE对PAR增加的响应
程度基本一致 , 且NEE增加的幅度基本相等 ; 随
PAR持续增强, 阴天和晴天NEE对PAR的响应差异
明显, 当PAR高于400 μmol CO2·m–2·s–1后, 阴天和
晴天的响应程度发生明显变化, 晴天的NEE增加幅
度明显大于阴天。当晴天PAR大于 1 400 μmol
CO2·m–2·s–1, NEE的增加趋势明显变弱, 维持稳定的
碳吸收峰值(11 μmol CO2·m–2·s–1左右)。
2.3 阴天和晴天条件下白天生态系统呼吸对温度
的响应
采用选取的12对阴天和晴天白天NEE数据通过
Mechaelis-Menten模型反推得到Reco,daytime, 结果表
明阴天和晴天Reco,daytime与T均存在显著的指数关系
(图4), 且晴天Reco,daytime显著高于阴天。晴天条件下,
气温可以解释生态系统呼吸变异的64%; 阴天, 气
温可以解释其变异的45%。晴天生态系统基础呼吸a
值 (0.09 μmol CO2·m–2·s–1)小于阴天 (1.43 μmol
CO2·m–2·s–1), 但是其温度反应系数b (0.17)却大于阴
天(0.06)。因此, 晴天生态系统呼吸的温度敏感系数
Q10 (5.5)远大于阴天(1.9)。
2.4 阴天和晴天PAR与T对湿地生态系统NEE的协
同影响
多元回归分析发现, T和PAR对晴天NEE的协同
影响达到40% (p < 0.01), 对阴天的协同影响为41%,
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 667
doi: 10.17521/cjpe.2015.0063
图3 2013年黄河三角洲湿地生长季阴天和晴天昼间生态系
统CO2交换(NEE)和光合有效辐射(PAR)的关系。黑线代表晴
天拟合曲线, 灰线代表阴天拟合曲线。
Fig. 3 Relationships between daytime net ecosystem ex-
change of CO2 (NEE) and photosynthetically active radiation
(PAR) between sunny days and cloudy days during the 2013
growing season in the Yellow River Delta wetland. Black solid
line represents fitting curve of sunny days, and grey line repre-
sents fitting curve of cloudy days.
图4 2013年黄河三角洲湿地生长季阴天和晴天昼间生态系
统呼吸(Reco,daytime)和气温(T)的关系。黑线代表晴天拟合曲线,
灰线代表阴天拟合曲线。
Fig. 4 Relationships between daytime ecosystem respiration
(Reco,daytime) and air temperature (T) on sunny days and cloudy
days during the 2013 growing season in the Yellow River Delta
wetland. Black solid line represents fitting curve of sunny days,
and grey line represents fitting curve of cloudy days.
偏相关分析发现T是晴天NEE变异的主控因子(T: R2
= 0.37, p < 0.001; PAR: R2 = 0.20, p < 0.001), PAR是
阴天NEE变异的主控因子(T: R2 = 0.10, p < 0.001;
PAR: R2 = 0.38, p < 0.001)。多元回归分析表明, ΔPAR
与ΔT对ΔNEE的协同影响达到63% (R2 = 0.63, p <
0.001; 表2), 说明PAR与T是引起阴天和晴天NEE差
异的主要环境因子。
3 讨论
3.1 阴天和晴天对湿地生态系统NEE光响应的
影响
本文研究发现晴天和阴天芦苇湿地NEE对PAR
的响应趋势一致, 均呈直角双曲线关系, 与先前的
很多研究结果一致(Falge et al., 2001; Monson et al.,
2002; Zhou et al., 2009; 张弥等, 2009; Han et al.,
2014a, 2014b; 邢庆会等, 2014)。PAR是控制阴天和
晴天生态系统生长季昼间NEE变化的主要因素
(Flanagan & Johnson, 2005; Liu et al., 2006; 薛红喜
等, 2012), Michaelis-Menten方程拟合发现, PAR可以
解释晴天单天NEE变化的57%–82%, 解释阴天单天
NEE变化的53%–81%。云层变化会改变地表接收太
阳辐射的强度, 影响PAR、T等环境因子, 进而影响
阴天和晴天条件下NEE对光的响应特征(Baldocchi,
1997; Freedman et al., 2001)。
在一定光照强度范围内, 光合作用随PAR的增
强而增加(Glenn et al., 2006; Syed et al., 2006; Hao et
al., 2011; 同小娟等, 2011)。光能过剩会对光合作用
产生不良影响, 出现光抑制, 致使叶绿体光合效率
下降(Jiang et al., 2011; Tholen et al., 2012)。晴天PAR
显著大于阴天(图2B), 因此, 晴天条件下植被叶片
光合作用可能大于阴天, 表现为晴天Amax显著大于
阴天(表1)。Zhou等(2009)研究认为Amax与植被的环
境条件有关, 其中晴天Amax较阴天条件下提高了
30%, 说明在植被生长旺季, 天空有云层覆盖时芦
苇的光合能力比晴朗天气无云时有所降低, Law等
(2002)总结全球森林、草地、农田以及苔原生态系
统碳交换相关研究也得出类似结论。阴天条件下,
伴随天空云量的增多, PAR显著降低(图2B), 尽管阴
天和晴天条件下, NEE均随PAR的增大而增加(图3),
但由于阴天PAR较低, 且晴天未出现光抑制现象,
因此其NEE显著低于晴天(图2A)。Alton (2008)在分
析北美洲和欧洲6种森林类型2–3年的碳通量观测数
据后发现 , 这些森林阴天的日固碳量比晴天少
60%–80%。相反, 在研究太阳辐射对黄河小浪底人
工混交林生态系统碳交换的影响中发现, 多云天气
下净碳交换会增加(刘佳等, 2014)。造成研究结论不
一致的原因是多方面的, 不同的阴天和晴天划分指
668 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
表2 多元回归分析黄河三角洲湿地生长季阴天和晴天光合有效辐射(PAR)与气温(T)对净生态系统CO2交换(NEE), 阴天和晴天PAR差量(ΔPAR)与T差
值(ΔT)对NEE差量(ΔNEE)的协同影响
Table 2 Estimated empirical coefficient of multiple liner regression models for changes in net ecosystem exchange (NEE) with photosynthetically active radia-
tion (PAR) and air temperature (T) on sunny and cloudy days during the growing season in the Yellow River Delta
方程 Equation R2 p n
晴天 Sunny day NEE = –0.005PAR – 0.28T + 4.06 0.41 <0.001 288
阴天 Cloudy day NEE = –0.006PAR – 0.107T + 2.67 0.42 <0.001 288
阴天和晴天差量 Difference between sunny and cloudy days ΔNEE = –0.004ΔPAR – 0.123ΔT – 2.54 0.63 <0.001 288
ΔNEE, 阴天和晴天NEE差量; ΔT, 气温差量。
ΔNEE, NEE difference between sunny and cloudy days; ΔT, air temperature difference between sunny and cloudy days.
标(Graham et al., 2003; Dengel & Grace, 2010)和拟
合模型(Zhang et al., 2011)来估计天气对碳通量的影
响, 散射光和直射光下的碳交换没有一直处在相同
的天气辐射条件下进行对比。此外, 研究地域的差
异和不同植被类型的特性也在很大程度上影响了碳
交换过程对天气的响应过程。
另外, 太阳辐射变化引起的温度变化也影响
NEE对光的响应特征。首先, 温度通过影响酶系列
化学反应对光合作用产生影响(Syed et al., 2006),
温度升高有利于光合速率的提高(Pingintha et al.,
2010)。相关分析发现, 阴天和晴天Amax与T均为显著
的线性正相关(晴天: R2 = 0.80, p < 0.05; 阴天: R2 =
0.63, p < 0.05), 其次, 生态系统呼吸与气温通常显
著正相关(Aires et al., 2008; Pingintha et al., 2010)。
本研究中虽然晴天条件下Reco,daytime较阴天提高了
20%, 但NEE却显著高于阴天的67%, 说明晴天温
度对湿地光合固碳能力的提高远超过生态系统呼吸
的消耗, 表现为晴天生态系统的碳汇功能更强, 这
与已有的研究结果一致(Han et al., 2014a)。
3.2 阴天和晴天对湿地生态系统呼吸温度响应的
影响
阴天和晴天生态系统Reco,daytime与T均呈显著的
正相关关系, 两者呈指数关系, 与以往很多研究的
结果一致(石培礼等, 2006; Zhou et al., 2009; Zhao et
al., 2010; Han et al., 2013, 2014a; 邢庆会等, 2014)。
T是影响生态系统呼吸的主要因素(Law et al., 2002;
Reichstein et al., 2005; Urban et al., 2007), 本文研究
发现: 黄河三角洲芦苇湿地晴天气温相对阴天提高
了10%, 其阴天和晴天的气温差高于美国阿尔卑斯
山脉南部森林的阴天和晴天的气温差 (Berry &
Smith, 2012), 黄河三角洲芦苇湿地晴天对应的生态
系统呼吸相对阴天提高了20% (p < 0.05), 说明阴天
条件下, 植被地上部分尤其是叶面温度较晴朗天气
强太阳辐射条件下的低, 叶片以及植被茎干呼吸受
到一定的抑制(Urban et al., 2007)。
Q10值被广泛应用于评价生态系统呼吸对温度
变化的敏感程度(杨庆朋等, 2011; 杨利琼等, 2013;
Han et al., 2014a, 2014b), Q10值越大, 说明生态系统
呼吸对温度变化的响应越敏感。黄河三角洲芦苇湿
地生态系统阴天和晴天Q10值均在已有的湿地Q10范
围(1.0–7.7)内(Chapman & Thurlow, 1996; Silvola et
al., 1996; Lafleur et al., 2001; Bonneville et al., 2008;
Zhou et al., 2009; 周丽艳等, 2010), 其中晴天白天
Q10为5.5, 远高于阴天白天的Q10 (1.9), 说明晴天白
天生态系统呼吸对温度变化的敏感性相对较高。分
析其原因, 一方面生态系统温度敏感性与气温有关
(Kirschbaum, 1995; Xu & Qi, 2001; Janssens & Pile-
gaard, 2003; Davidson & Janssens., 2006; 张雷明等,
2006; Jassal et al., 2008), 气温对Q10产生影响主要
通过影响光合与呼吸作用酶的活性实现(Davidson
& Janssens, 2006)。晴天气温T ((23.56 ± 2.62) )℃ 显
著大于阴天((21.26 ± 2.34) ), ℃ 阴天由于酶促反应
需要一定的活化酶, 光合与呼吸作用酶的活性一般
受到限制; 而晴天随着辐射增强, 气温升高, 越来
越多的分子达到或超过了自身的活化能, 反应加快
(Xiang & Freeman, 2009; Karhu et al., 2010)。另一方
面, 晴天相对阴天较高的PAR使得晴天光合作用更
强, 产生输送的有机质增多(Curiel Yuste et al., 2007;
Jassal et al., 2008), 自养呼吸增强, 同时地上植被以
及土壤异养微生物呼吸对气温的响应能力增强
(Edwards et al., 2004; Heinemeyer et al., 2006; Moy-
ano et al., 2008), 而阴天由于底物基质供应不足使得
自养、异养呼吸受到抑制(Gershenson et al., 2009)。
3.3 本研究的特色与不足
本研究以黄河三角洲芦苇湿地为研究对象, 在
自然条件下选择相邻的阴天和晴天, 在生物要素
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 669
doi: 10.17521/cjpe.2015.0063
(生物量、叶面积指数)、土壤水分以及养分特征保
持不变的前提下, 分析阴天和晴天引起的辐射变化
对生态系统NEE的影响机制。目前, 有关太阳辐射
对生态系统NEE的影响机制大都以晴空指数为指标
(Gu et al., 2003; Liu et al., 2006; 范玉枝等, 2009;
Zhang et al., 2010; 周丽艳等, 2010; 蒋琰等, 2011;
Zhao et al., 2011; 刘佳等, 2014)。这种研究方法的最
大不足就是研究阶段中, 太阳辐射、生物要素(生物
量、叶面积指数)、土壤湿度等环境因子都在发生变
化, 这对阐明太阳辐射这一单因素对NEE的控制机
制研究带来一定困难。而本研究巧妙地在自然条件
下选择相邻的阴天和晴天, 在日尺度上实现了对单
一变量PAR的控制。利用这种研究方法 , Han等
(2014a)通过对比分析阴天和晴天植物冠层光合作
用的差异性, 定量分析了光合作用在日尺度上对土
壤呼吸的调节作用。此外, 我们已有研究发现PAR
改变所引起的植物光合作用变化对生态系统呼吸会
产生一定的影响(Tang et al., 2005; Baldocchi et al.,
2006; Moyano et al., 2008; Wingate et al., 2010; Han
et al., 2012)。但是, 以往的研究多通过夜间生态系
统呼吸与气温函数关系外延的方法来估算白天生态
系统呼吸(Doughty et al., 2010; Zhang et al., 2011),
忽略了PAR对白天生态系统呼吸的影响, 因而具有
一定的局限性。考虑到白天PAR的变化, 本研究采用
Michaelis-Menten模型对白天生态系统呼吸进行推
算, 使得生态系统呼吸的温度响应数据更具有说服
力。
本研究通过利用自然条件下阴天和晴天的转
换, 较好地证明了阴天和晴天引起的太阳辐射变化
对湿地生态系统碳吸收功能的影响, 为云量以及大
气气溶胶含量变化对区域CO2交换的潜在影响提供
了有力证据。本研究只涉及生长季节的12对阴天和
晴天数据, 数据并没有涵盖整个生长季, 而且由于9
月份连续降雨, 我们并没有在9月份找到相邻的阴
天和晴天数据对。此外, 本次研究我们主要探讨了
PAR对生态系统生长季NEE的影响, 而NEE是植被
光合固定碳(生态系统总生产力, GPP)与生态系统
呼吸释放碳(生态系统呼吸, Reco)之间相互平衡的结
果, PAR对植被光合作用以及生态系统呼吸强度的
影响机制, 本次研究没有涉及。因此, 在下一步研究
中, 除了加强对生长季生态系统NEE以及环境因子
长期的、连续观测外, 增加植被光合作用的探讨有
助于深刻理解分析PAR变化对黄河三角洲芦苇湿地
生态系统碳收支过程产生的影响。
基金项目 国家自然科学基金(41301083)和国家科
技支撑计划项目(2011BAC02-B01)。
致谢 感谢中国科学院黄河三角洲滨海湿地生态试
验站杨长利、马秀枝在野外监测工作中给予的帮助。
参考文献
Aires LMI, Pio CA, Pereira JS (2008). Carbon dioxide ex-
change above a Mediterranean C3/C4 grassland during two
climatologically contrasting years. Global Change Biol-
ogy, 14, 539–555.
Alton PB (2008). Reduced carbon sequestration in terrestrial
ecosystems under overcast skies compared to clear skies.
Agricultural and Forest Meteorology, 148, 1641–1653.
Alton PB, North PR, Los SO (2007). The impact of diffuse
sunlight on canopy light-use efficiency, gross photosyn-
thetic product and net ecosystem exchange in three forest
biomes. Global Change Biology, 13, 776–787.
Bai YF, Wang J, Zhang BC, Zhang ZH, Liang J (2012). Com-
paring the impact of cloudiness on carbon dioxide ex-
change in a grassland and a maize cropland in northwest-
ern China. Ecological Research, 27, 615–623.
Baldocchi D (1997). Measuring and modelling carbon dioxide
and water vapour exchange over a temperate broad-leaved
forest during the 1995 summer drought. Plant, Cell & En-
vironment, 20, 1108–1122.
Baldocchi D, Tang JW, Xu LK (2006). How switches and lags
in biophysical regulators affect spatial-temporal variation
of soil respiration in an oak-grass savanna. Journal of
Geophysical Research: Biogeosciences, 111, G02008.
Bar-Or RZ, Koren I, Altaratz O (2010). Estimating cloud field
coverage using morphological analysis. Environmental
Research Letters, 5, 123–129.
Berry ZC, Smith WK (2012). Cloud pattern and water relations
in Picea rubens and Abies fraseri, southern Appalachian
Mountains, USA. Agricultural and Forest Meteorology,
162–163, 27–34.
Bonneville MC, Strachan IB, Humphreys ER, Roulet NT
(2008). Net ecosystem CO2 exchange in a temperate cattail
marsh in relation to biophysical properties. Agricultural
and Forest Meteorology, 148, 69–81.
Bu RC, Wang XL, Xiao DN (1999). Analysis on landscape
elements and fragmentation of Yellow River delta. Chinese
Journal of Applied Ecology, 10, 321–324. (in Chinese with
English abstract) [布仁仓, 王宪礼, 肖笃宁 (1999). 黄
河三角洲景观组分判定与景观破碎化分析. 应用生态
学报, 10, 321–324.]
Chapman SJ, Thurlow M (1996). The influence of climate on
CO2 and CH4 emissions from organic soils. Agricultural
670 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
and Forest Meteorology, 79, 205–217.
Cui SQ (2002). Influence of water discharge cut-off of Huanghe
on environment of its delta. Marine Sciences, 26(7),
42–46. (in Chinese with English abstract) [崔树强 (2002).
黄河断流对黄河三角洲生态环境的影响. 海洋科学,
26(7), 42–46.]
Curiel Yuste J, Baldocchi DD, Gershenson A, Goldstein A,
Misson L, Wong S (2007). Microbial soil respiration and
its dependency on carbon inputs, soil temperature and
moisture. Global Change Biology, 13, 2018–2035.
Davidson EA, Janssens IA (2006). Temperature sensitivity of
soil carbon decomposition and feedbacks to climate
change. Nature, 440, 165–173.
Dengel S, Grace J (2010). Carbon dioxide exchange and canopy
conductance of two coniferous forests under various sky
conditions. Oecologia, 164, 797–808.
Doughty CE, Flanner MG, Goulden ML (2010). Effect of
smoke on subcanopy shaded light, canopy temperature,
and carbon dioxide uptake in an Amazon rainforest.
Global Biogeochemical Cycles, 24, GB3015.
Edwards EJ, Benham DG, Marland LA, Fitter AH (2004). Root
production is determined by radiation flux in a temperate
grassland community. Global Change Biology, 10,
209–227.
Falge E, Baldocchi D, Olson R, Anthoni P, Aubinet M, Bern-
hofer C, Burba G, Clement R, Dolman H, Granier A,
Gross P, Grünwald T, Hollinger D, Jensen NO, Katul G,
Keronen P, Kowalski A, Lai CT, Law BE, Meyers T,
Moncrieff J, Moors E, Munger JW, Pilegaard K, Rannik
Ü, Rebmann C, Suyker A, Tenhunen J, Tu K, Verma S,
Vesala T, Wilson K, Wofsy S (2001). Gap filling strate-
gies for defensible annual sums of net ecosystem ex-
change. Agricultural and Forest Meteorology, 107, 43–69.
Fan YZ, Zhang XZ, Shi PL (2009). Influence of diffuse radia-
tion on the net CO2 exchange of alpine meadow ecosystem
on Tibet Plateau. Geographical Research, 28, 1673–1681.
(in Chinese with English abstract) [范玉枝, 张宪洲, 石培
礼 (2009). 散射辐射对西藏高原高寒草甸净生态系统
CO2交换的影响. 地理研究, 28, 1673–1681.]
Flanagan LB, Johnson BG (2005). Interacting effects of tem-
perature, soil moisture and plant biomass production on
ecosystem respiration in a northern temperate grassland.
Agricultural and Forest Meteorology, 130, 237–253.
Freedman JM, Fitzjarrald DR, Moore KE, Sakai RK (2001).
Boundary layer clouds and vegetation-atmosphere feed-
backs. Journal of Climate, 14, 180–197.
Gershenson A, Bader NE, Cheng WX (2009). Effects of sub-
strate availability on the temperature sensitivity of soil or-
ganic matter decomposition. Global Change Biology, 15,
176–183.
Glenn AJ, Flanagan LB, Syed KH, Carlson PJ (2006). Com-
parison of net ecosystem CO2 exchange in two peatlands
in western Canada with contrasting dominant vegetation,
Sphagnum and Carex. Agricultural and Forest Meteorol-
ogy, 140, 115–135.
Graham EA, Mulkey SS, Kitajima K, Phillips NG, Wright SJ
(2003). Cloud cover limits net CO2 uptake and growth of a
rainforest tree during tropical rainy seasons. Proceedings
of the National Academy of Sciences of the United States
of America, 100, 572–576.
Gu LH, Baldocchi D, Verma SB, Black TA, Vesala T, Falge
EM, Dowty PR (2002). Advantages of diffuse radiation for
terrestrial ecosystem productivity. Journal of Geophysical
Research, 107, ACL 2-1-ACL 2-23 D6, doi: 10.1029/2001
JD001242.
Gu LH, Fuentes JD, Shugart HH, Staebler RM, Black TA
(1999). Responses of net ecosystem exchanges of carbon
dioxide to changes in cloudiness: Results from two North
American deciduous forests. Journal of Geophysical Re-
search, 104, 31421–31434.
Gu S, Tang YH, Du MY, Kato T, Li YN, Cui XY, Zhao XQ
(2003). Short-term variation of CO2 flux in relation to en-
vironmental controls in an alpine meadow on the Qinghai-
Tibetan Plateau. Journal of Geophysical Research, 108,
4670.
Han GX, Luo YQ, Li DJ, Xia JY, Xing QH, Yu JB (2014a).
Ecosystem photosynthesis regulates soil respiration on a
diurnal scale with a short-term time lag in a coastal wet-
land. Soil Biology & Biochemistry, 68, 85–94.
Han GX, Xing QH, Yu JB, Luo YQ, Li DJ, Yang LQ, Wang
GM, Mao PL, Xie BH, Mikle N (2014b). Agricultural rec-
lamation effects on ecosystem CO2 exchange of a coastal
wetland in the Yellow River Delta. Agriculture, Ecosys-
tems and Environment, 196, 187–198.
Han GX, Yang LQ, Yu JB, Wang GM, Mao PL, Gao YJ
(2013). Environmental controls on net ecosystem CO2 ex-
change over a reed (Phragmites australis) wetland in the
Yellow River Delta, China. Estuaries and Coasts, 36,
401–413.
Han GX, Yu JB, Li HB, Yang LQ, Wang GM, Mao PL, Gao
YJ (2012). Winter soil respiration from different vegeta-
tion patches in the Yellow River Delta, China. Environ-
mental Management, 50, 39–49.
Hao YB, Cui XY, Wang YF, Mei XR, Kang XM, Wu N, Luo
P, Zhu D (2011). Predominance of precipitation and tem-
perature controls on ecosystem CO2 exchange in Zoige al-
pine wetlands of southwest China. Wetlands, 31, 413–422.
Heinemeyer A, Ineson P, Ostle N, Fitter AH (2006). Respira-
tion of the external mycelium in the arbuscular mycorrhi-
zal symbiosis shows strong dependence on recent photo-
synthates and acclimation to temperature. New Phytolo-
gist, 171, 159–170.
Janssens IA, Pilegaard K (2003). Large seasonal changes in Q10
of soil respiration in a beech forest. Global Change Biol-
ogy, 9, 911–918.
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 671
doi: 10.17521/cjpe.2015.0063
Jassal RS, Black TA, Novak MD, Gaumont-Guay D, Nesic Z
(2008). Effect of soil water stress on soil respiration and its
temperature sensitivity in an 18-year-old temperate Douglas-
fir stand. Global Change Biology, 14, 1305–1318.
Jia X, Wang WC, Chen YH, Huang JP, Chen JM, Zhang H, Bai
HT, Zhang P (2010). Influence of dust aerosols on cloud
radiative forcing over Northern China. China Environ-
mental Science, 30, 1009–1014. (in Chinese with English
abstract) [贾漩, 王文彩, 陈勇航, 黄建平, 陈建民, 张
华, 白鸿涛, 张萍 (2010). 华北地区沙尘气溶胶对云辐
射强迫的影响. 中国环境科学, 30, 1009–1014.]
Jiang CD, Wang X, Gao HY, Shi L, Chow WS (2011). Sys-
temic regulation of leaf anatomical structure, photosyn-
thetic performance, and high-light tolerance in Sorghum.
Plant Physiology, 155, 1416–1424.
Jiang Y, Hu HB, Zhang XS, Xue JH (2011). The carbon flux
and its environmental factors in a north subtropical secon-
dary oak forest ecosystem. Journal of Nanjing Forestry
University (Natural Science Edition), 35(3), 38–42. (in
Chinese with English abstract) [蒋琰, 胡海波, 张学仕,
薛建辉 (2011). 北亚热带次生栎林碳通量及其影响因
子研究. 南京林业大学学报(自然科学版), 35(3), 38–42.]
Karhu K, Fritze H, Tuomi M, Vanhala P, Spetz P, Kitunen V,
Liski J (2010). Temperature sensitivity of organic matter
decomposition in two boreal forest soil profiles. Soil Biol-
ogy & Biochemistry, 42, 72–82.
Kirschbaum MUF (1995). The temperature dependence of soil
organic-matter decomposition, and the effect of global
warming on soil organic C storage. Soil Biology & Bio-
chemistry, 27, 753–760.
Lafleur PM, Roulet NT, Admiral SW (2001). Annual cycle of
CO2 exchange at a bog peatland. Journal of Geophysical
Research: Atmospheres, 106, 3071–3081.
Law BE, Falge E, Gu L, Baldocchi DD, Bakwin P, Berbigier P,
Davis K, Dolman AJ, Falk M, Fuentes JD, Goldstein A,
Granier A, Grelle A, Hollinger D, Janssens IA, Jarvis P,
Jensen NO, Katul G, Mahli Y, Matteucci G, Meyers T,
Monson R, Munger W, Oechel W, Olson R, Pilegaard K,
Paw U KT, Thorgeirsson H, Valentini R, Verma S, Vesala
T, Wilson K, Wofsy S (2002). Environmental controls
over carbon dioxide and water vapor exchange of terres-
trial vegetation. Agricultural and Forest Meteorology, 113,
97–120.
Letts MG, Lafleur PM, Roulet NT (2005). On the relationship
between cloudiness and net ecosystem carbon dioxide ex-
change in a peatland ecosystem. Ecoscience, 12, 53–59.
Liu J, Tong XJ, Zhang JS, Meng P, Li J, Zheng N (2014). Im-
pacts of solar radiation on net ecosystem carbon exchange
in a mixed plantation in the Xiaolangdi Area. Acta
Ecologica Sinica, 34, 2118–2127. (in Chinese with Eng-
lish abstract) [刘佳, 同小娟, 张劲松, 孟平, 李俊, 郑宁
(2014). 太阳辐射对黄河小浪底人工混交林净生态系统
碳交换的影响. 生态学报, 34, 2118–2127.]
Liu YF, Yu GR, Wen XF, Wang YH, Song X, Li J, Sun XM,
Yang FT, Chen YR, Liu QJ (2006). Seasonal dynamics of
CO2 fluxes from subtropical plantation coniferous ecosys-
tem. Science in China Series D: Earth Sciences, 49,
99–109.
Lloyd J, Taylor JA (1994). On the temperature dependence of
soil respiration. Functional Ecology, 8, 315–323.
Ma JY, Liang H, Luo Y, Li SK (2011). Variation trend of direct
and diffuse radiation in China over recent 50 years. Acta
Physica Sinica, 60, 859–872. (in Chinese with English ab-
stract) [马金玉, 梁宏, 罗勇, 李世奎 (2011). 中国近50
年太阳直接辐射和散射辐射变化趋势特征. 物理学报,
60, 859–872.]
Min QL (2005). Impacts of aerosols and clouds on forest-
atmosphere carbon exchange. Journal of Geophysical Re-
search: Atmospheres, 110, D06203. doi: 10.1029/2004
JD004858.
Monson RK, Turnipseed AA, Sparks JP, Harley PC,
Scott-Denton LE, Sparks K, Huxman TE (2002). Carbon
sequestration in a high-elevation, subalpine forest. Global
Change Biology, 8, 459–478.
Moyano FE, Kutsch WL, Rebmann C (2008). Soil respiration
fluxes in relation to photosynthetic activity in broad-leaf
and needle-leaf forest stands. Agricultural and Forest Me-
teorology, 148, 135–143.
Mu CC, Shi LY, Sun XX (2009). Fluxes and controls of CO2,
CH4 and N2O in a marsh wetland of Xiaoxing’an Moun-
tains, northeastern China. Chinese Journal of Plant Ecol-
ogy, 33, 617–623. (in Chinese with English abstract) [牟长
城, 石兰英, 孙晓新 (2009). 小兴安岭典型草丛沼泽湿
地CO2、CH4和N2O的排放动态及其影响因素. 植物生态
学报, 33, 617–623.]
Niyogi D, Chang HI, Saxena VK, Holt T, Alapaty K, Booker F,
Chen F, Davis KJ, Holben B, Matsui T, Meyers T, Oechel
WC, Peilke RA, Well R, Wilson K, Xue YK (2004). Di-
rect observations of the effects of aerosol loading on net
ecosystem CO2 exchanges over different landscapes.
Geophysical Research Letters, 31, L20506.
Pingintha N, Leclerc MY, Beasley JP, Durden D, Zhang G,
Senthong C, Rowland D (2010). Hysteresis response of
daytime net ecosystem exchange during drought. Biogeo-
sciences, 7, 1159–1170.
Qi Y, Fang SB, Zhou WZ (2014). Variation and spatial distri-
bution of surface solar radiation in China over recent 50
years. Acta Ecologica Sinica, 34, 7444–7453. (in Chinese
with English abstract) [齐月, 房世波, 周文佐 (2014).
近50年来中国地面太阳辐射变化及其空间分布. 生态
学报, 34, 7444–7453.]
Reichstein M, Fagle E, Baldocchi D, Palale D, Aubinet M,
Berbigier P, Bernhofer C, Buchmann N, Gilmanov T,
672 植物生态学报 Chinese Journal of Plant Ecology 2015, 39 (7): 661–673
www.plant-ecology.com
Granier A, Grünwald T, Havránková K, Ilvesniemi H, Ja-
nous D, Knohl A, Laurila T, Lohila A, Loustau D, Mat-
teucci G, Meyer T, Migiletta F, Ourcival JM, Pumpaney J,
Rambal S, Rotenberg E, Sanz M, Tenhunen J, Seufert G,
Vaccari F, Vesala T, Yakir D, Valentini R (2005). On the
separation of net ecosystem exchange into assimilation and
ecosystem respiration: Review and improved algorithm.
Global Change Biology, 11, 1424–1439.
Roderick ML, Farquhar GD, Berry SL, Noble IR (2001). On
the direct effect of clouds and atmospheric particles on the
productivity and structure of vegetation. Oecologia, 129,
21–30.
Ruimy A, Jarvis PG, Baldocchi DD, Saugier B (1995). CO2
fluxes over plant canopies and solar radiation: A review.
Advances in Ecological Research, 26, 1–68.
Sasaki A, Hagimori Y, Nakatubo T, Hoshika A (2009). Tidal
effects on the organic carbon mineralization rate under
aerobic conditions in sediments of an intertidal estuary.
Ecological Research, 24, 723–729.
Shi PL, Sun XM, Xu LL, Zhang XZ, He YT, Zhang DQ, Yu
GR (2006). The net ecosystem CO2 exchange and its in-
fluence factor in pole grass meadow, Tibet Plateau. Sci-
ence in China Series D: Earth Sciences, 36, 194–203. (in
Chinese) [石培礼, 孙晓敏, 徐玲玲, 张宪洲, 何永涛,
张东秋, 于贵瑞 (2006). 西藏高原草原化嵩草草甸生态
系统CO2净交换及其影响因子. 中国科学D辑: 地球科
学, 36, 194–203.]
Silvola J, Alm J, Ahlholm U, Nykanen H, Martikainen PJ
(1996). CO2 fluxes from peat in boreal mires under vary-
ing temperature and moisture conditions. Journal of Ecol-
ogy, 84, 219–228.
Still CJ, Riley WJ, Biraud SC, Noone DC, Buenning NH,
Randerson JT, Torn MS, Welker J, White JWC, Vachon
R, Farquhar GD, Berry JA (2009). Influence of clouds and
diffuse radiation on ecosystem-atmosphere CO2 and
CO18O exchanges. Journal of Geophysical Research Bio-
geosciences, 114, G01018. doi: 10.1029/2007JG000675.
Syed KH, Flanagen LB, Carlson PJ, Glenn AJ, van Gaalen KE
(2006). Environmental control of net ecosystem CO2 ex-
change in a treed, moderately rich fen in northern Alberta.
Agricultural and Forest Meteorology, 140, 97–114.
Tang JW, Baldocchi DD, Xu LK (2005). Tree photosynthesis
modulates soil respiration on a diurnal time scale. Global
Change Biology, 11, 1298–1304.
Tholen D, Boom C, Zhu XG (2012). Opinion: Prospects for
improving photosynthesis by altering leaf anatomy. Plant
Science, 197, 92–101.
Tong XJ, Li J, Liu D (2011). Characteristics and controlling
factors of photosynthesis in a maize ecosystem on the
North China Plain. Acta Ecologica Sinica, 31, 4889–4899.
(in Chinese with English abstract) [同小娟, 李俊, 刘渡
(2011). 华北平原玉米田生态系统光合作用特征及影响
因素. 生态学报, 31, 4889–4899.]
Urban O, Janouš D, Acosta M, Czerný R, Marková I, Navrátil
M, Pavelka M, Pokorný R, Šprtová M, Zhang R, Špunda
V, Grace J, Marek MV (2007). Ecophysiological controls
over the net ecosystem exchange of mountain spruce
stand. Comparison of the response in direct vs. diffuse so-
lar radiation. Global Change Biology, 13, 157–168.
Wingate L, Ogée J, Burlett R, Bosc A, Devaux M, Grace J,
Loustau D, Gessler A (2010). Photosynthetic carbon iso-
tope discrimination and its relationship to the carbon iso-
tope signals of stem, soil and ecosystem respiration. New
Phytologist, 188, 576–589.
Xiang W, Freeman C (2009). Annual variation of temperature
sensitivity of soil organic carbon decomposition in North
peatlands: Implications for thermal responses of carbon
cycling to global warming. Environmental Geology, 58,
499–508.
Xing QH, Han GX, Yu JB, Wu LX, Yang LQ, Mao PL, Wang
GM, Xie BH (2014). Net ecosystem CO2 exchange and its
controlling factors during the growing season in an
inter-tidal salt marsh in the Yellow River Estuary, China.
Acta Ecologica Sinica, 34, 4966–4979. (in Chinese with
English abstract) [邢庆会, 韩广轩, 于君宝, 吴立新, 杨
利琼, 毛培利, 王光美, 谢宝华 (2014). 黄河口潮间盐
沼湿地生长季净生态系统CO2交换特征及其影响因素.
生态学报, 34, 4966–4979.]
Xu M, Qi Y (2001). Spatial and seasonal variations of Q10 de-
termined by soil respiration measurements at a Sierra Ne-
vadan forest. Global Biogeochemical Cycles, 15, 687–696.
Xue HX, Li F, Li Q, Wang LX, Wang YL, Hu ZH (2012). Re-
search progress on carbon flux over agro-ecosystem based
on the eddy covariance method in China. Journal of Nan-
jing University of Information Science and Technology, 4,
226–232. (in Chinese with English abstract) [薛红喜, 李
峰, 李琪, 王连喜, 王云龙, 胡正华 (2012). 基于涡度
相关法的中国农田生态系统碳通量研究进展. 南京信
息工程大学学报, 4, 226–232.]
Yang LQ, Han GX, Yu JB, Wu LX, Zhu M, Xing QH, Wang
GM, Mao PL (2013). Effects of reclamation on net eco-
system CO2 exchange in wetland in the Yellow River
Delta, China. Chinese Journal of Plant Ecology, 37,
503–516. (in Chinese with English abstract) [杨利琼, 韩
广轩, 于君宝, 吴立新, 朱敏, 邢庆会, 王光美, 毛培利
(2013). 开垦对黄河三角洲湿地净生态系统CO2交换的
影响. 植物生态学报, 37, 503–516.]
Yang QP, Xu M, Liu HS, Wang JS, Liu LX, Chi YG, Zheng
YP (2011). Impact factors and uncertainties of the tem-
perature sensitivity of soil respiration. Acta Ecologica
Sinica, 31, 2301–2311. (in Chinese with English abstract)
[杨庆朋, 徐明, 刘洪升, 王劲松, 刘丽香, 迟永刚, 郑
云普 (2011). 土壤呼吸温度敏感性的影响因素和不确
初小静等: 阴天和晴天对黄河三角洲芦苇湿地净生态系统 CO2交换的影响 673
doi: 10.17521/cjpe.2015.0063
定性. 生态学报, 31, 2301–2311.]
Zhang BC, Cao JJ, Bai YF, Yang SJ, Hu L, Ning ZG (2011).
Effects of cloudiness on carbon dioxide exchange over an
irrigated maize cropland in northwestern China. Biogeo-
sciences Discussions, 8, 1669–1691.
Zhang LM, Yu GR, Sun XM, Wen XF, Ren CY, Song X, Liu
YF, Guan DX, Yan JH, Zhang YP (2006). Seasonal varia-
tion of carbon exchange of typical forest ecosystems along
the eastern forest transect in China. Science in China Se-
ries D: Earth Sciences, 49, 47–62. (in Chinese) [张雷明,
于贵瑞, 孙晓敏, 温学发, 任传友, 宋霞, 刘允芬, 关德
新, 闫俊华, 张一平 (2006). 中国东部森林样带典型生
态系统碳收支的季节变化. 中国科学D辑: 地球科学,
36, 45–59.]
Zhang M, Yu GR, Zhang LM, Sun XM, Wen XF, Han SJ
(2009). Effects of solar radiation on net ecosystem ex-
change of broadleaved-korean pine mixed forest in
Changbai Mountain, China. Chinese Journal of Plant
Ecology, 33, 270–282. (in Chinese with English abstract)
[张弥 , 于贵瑞 , 张雷明 , 孙晓敏 , 温学发 , 韩士杰
(2009). 太阳辐射对长白山阔叶红松林净生态系统碳交
换的影响. 植物生态学报, 33, 270–282.]
Zhang M, Yu GR, Zhang LM, Sun XM, Wen XF, Han SJ, Yan
JH (2010). Impact of cloudiness on net ecosystem ex-
change of carbon dioxide in different types of forest eco-
systems in China. Biogeosciences Discussions, 6,
8215–8245.
Zhao L, Li J, Xu S, Zhou H, Li Y, Gu S, Zhao X (2010). Sea-
sonal variations in carbon dioxide exchange in an alpine
wetland meadow on the Qinghai-Tibetan Plateau. Biogeo-
sciences, 7, 1207–1221.
Zhao ZH, Zhang LP, Kang WX, Tian DL, Xiang WH, Yan
WD, Peng CH (2011). Characteristics of CO2 flux in a
Chinese fir plantation ecosystem in Huitong County, Hu-
nan Province. Scientia Silvae Sinicae, 47, 6–12.
Zheng Y, Zhao Z, Zhou H, Zhou JJ (2011). Effects of sunny
and cloudy days on photosynthetic and physiological
characteristics of Black Locust. Scientia Silvae Sinicae,
47(5), 60–67. (in Chinese with English abstract) [郑元, 赵
忠, 周慧, 周靖靖 (2011). 晴天和阴天对刺槐光合生理
特性的影响. 林业科学, 47(5), 60–67.]
Zhou L, Zhou GS, Jia QY (2009). Annual cycle of CO2 ex-
change over a reed (Phragmites australis) wetland in
Northeast China. Aquatic Botany, 91, 91–98.
Zhou LY, Jia BR, Zeng W, Wang Y, Zhou GS (2010). Net
ecosystem CO2 exchange of virgin Larix gmelinii forest
and its characteristics of light response. Acta Ecologica
Sinica, 30, 6919–6926. (in Chinese with English abstract)
[周丽艳, 贾丙瑞, 曾伟, 王宇, 周广胜 (2010). 原始兴
安落叶松林生长季净生态系统CO2交换及其光响应特
征. 生态学报, 30, 6919–6926.]
责任编委: 陈世苹 责任编辑: 王 葳