摘要
人工林蒸散的影响机制研究对指导我国林业生态工程建设有重要意义。基于涡度相关技术,对华北低丘山区30年生栓皮栎-刺槐-侧柏人工混交林进行了连续2a的观测,以探讨蒸散的控制因子。结果表明:退耦系数(Ω)与冠层导度的季节动态有很好的一致性。2007、2008年的快速生长季Ω变化范围分别为0.12—0.62、0.08—0.54,平均值分别为0.37、0.23,快速生长季蒸散主要受气孔控制。2008年比2007年偏旱,该年快速生长季的退耦系数、冠层导度和蒸散低于2007年,发生干旱时蒸散主要受气孔限制。气孔对蒸散的限制作用在大气湿度较低时较高,并且这种限制作用在发生干旱时会进一步加剧。快速生长季内辐射是影响蒸散的主要环境因子,辐射资源丰富的年份气孔对蒸散的控制程度更高。
Water flux was measured continuously in fast growing season （ from June to August） in 2007 and 2008 using the eddy covariance technique in a 30-year-old mixed plantation （ Quercus variabilis, Robinia pseudoacacia and Platycladus orientalis） in a hilly area of the North China. The results showed that seasonal variation of decoupling coefficient （Ω） and canopy conductance （ gc ） had a similar pattern. Range of /2 in 2007 and 2008 were 0.12-0. 62 and 0.08-0. 54 respectively. Average values of/2 in these two years were 0.37 and 0.23. Evapotranspiration （ET） was mainly controlled by stomatal movement in fast growing season. It was dryer in 2008 than in 2007, and the averages of/2, gc and ET in 2008 were also lower than those in 2007. Stomatal control was the main impact factor on ET in drought. The restriction from stomata on ET was higher in lower atmosphere humidity, and the restriction was aggravated in drought. Radiation was the main environmental factor that affects ET in fast growing season, and drought enhanced the control of radiation on ET. Stomatal control was stronger in the year with higher radiation.
出处
《生态学报》
CAS
CSCD
北大核心
2014年第3期667-673,共7页
Acta Ecologica Sinica
基金
国家自然科学基金青年基金项目(31100321)
林业公益性行业科研专项课题(201104009-04)
关键词
蒸散
退耦系数
气孔运动
干旱
辐射
evapotranspiration
decoupling coefficient
stomatal movement
drought
radiation
