Seasonal contribution and interannual variation of evapotranspiration over a reed marsh (Phragmites australis) in Northeast China from 3‐year eddy covariance data
Seasonal contribution and interannual variation of evapotranspiration over a reed marsh (Phragmites australis) in Northeast China from 3‐year eddy covariance data
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DOI：
10.1002/hyp.7545
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发表时间：
2010-04
影响因子：
3.2
通讯作者：
Li Zhou;Guangsheng Zhou;Shuhua Liu;Xinghua Sui
中科院分区：
文献类型：
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作者：
Li Zhou;Guangsheng Zhou;Shuhua Liu;Xinghua Sui
目前，与气候变化相关的一个尚未解决的关键问题是蒸散量（ET）是否随着全球变暖而增加或减少。因此，人们对研究各种生态系统中的ET产生了极大的兴趣，以更好地了解控制相互作用的性质以及ET与其他生态系统过程之间的联系。特别是在湿地环境中，对ET的研究相对较少。利用涡度相关法对辽河三角洲芦苇湿地进行了3年（2005-2007年）的蒸散观测。分析了日蒸散量及其主要控制因子的季节和年际变化。2005年、2006年和2007年芦苇沼泽的年蒸散量分别为432、480和445 mm。非生长季的ET贡献不可忽略;在调查年份，其范围为年ET的13%至16%。在年度过程中，ET增加与温度升高和芦苇植物生长在4月下旬和5月上旬，并在快速生长季节达到峰值，每周平均速率为3.7 mm day−1（2005），3.7 mm day−1（2006）和3.4 mm day−1（2007）。解耦因子（Ω）也存在季节性变化，其最小值出现在非生长季，最大值出现在快速生长季，尤其是在7月。在生长旺盛期，解耦因子（Ω）一般在0.5 ~ 0.8之间，表明太阳辐射是影响蒸散的主要因子，而不是水汽压亏缺（VPD）。此外，生物因子和冠层传导也控制着芦苇沼泽蒸散量的年际变化。研究结果将有助于更好地了解这一特殊的芦苇沼泽的ET。版权所有© 2009约翰威利父子有限公司。
At present, one of unresolved critical issues relating to climate change is whether evapotranspiration (ET) is increasing or decreasing with global warming. There has been great interest, therefore, in studying ET in a variety of ecosystems to better understand the nature of the controlling interactions and the links between ET and other ecosystem processes. Especially, relatively few studies on ET have been conducted in wetland environments. In this paper, we present the results from 3 years (2005–2007) of direct ET measurements, using eddy covariance method, over a reed (Phragmites australis) marsh in Liaohe Delta, Northeast China. The seasonal and interannual variation of daily ET and its main controls were analysed. Annual ET for the reed marsh was 432, 480, and 445 mm in 2005, 2006 and 2007, respectively. The contribution of ET during non‐growing season was not negligible; it ranged from 13% to 16% of the annual ET for the investigated years. On annual course, ET increased associating with increasing temperature and reed plant growth in late‐April and early‐May, and peaked in the rapid growing season with weekly mean rates of 3·7 mm day−1 (2005), 3·7 mm day−1 (2006), and 3·4 mm day−1 (2007). Decoupling factor (Ω) also varied seasonally, with its minimum values occurred in the non‐growing season and the maximum values in the rapid growing season, especially in July. During the rapid growing season, the values of decoupling factor (Ω) were generally between 0·5 and 0·8, indicating that solar radiation was main factor affecting ET other than vapour pressure deficit (VPD). Moreover, biological factor and canopy conduction also controlled the interannual ET variation in the reed marsh. The results would be helpful to better understand ET for this particular reed marsh. Copyright © 2009 John Wiley & Sons, Ltd.