Sap flow response of Eucaylyptus (Eucalyptus urophylla) to environmental stress in South China |
| ------------------------------------------------------------------------------------------ |
|
出 版 社：Journal of Zhejiang University Science |
|
发表时间：2004 |
|
台 站：鼎湖山森林生态系统定位研究站 |
|
作 者：Yin Guangcai，Zhou Guoyi，Jim Morris，Huang Zhihong，Chu Guowei，Zhou guangyi
|
|
点 击 率：588564 |
| ------------------------------------------------------------------------------------------ |
|
关 键 字(英文)：Sap flow,Environmental stress, Eucalyptus plantations, Water conductivity |
| 摘 要(英文)：Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2=0.76, P=0.01 at Hetou and R2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X3+15147X2-1250.7X+2278.4 (R2=0.68; P=0.01) at Hetou and Y=-101.67X3-1.65X2-376.4X+1914.8 (R2=0.40,P=0.05) at Jijia, where Y was daily SFD,X was daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa, within which daily SFD varied from 540±70 L/(m2·d) to 4739±115 L/(m2·d) at Hetou site, from 397±26 L/(m2·d) to 3414±191 L/(m2·d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity(<30%)and slightly lower under high relative humidity(>80%)compared with those at the Jijia site;(3)The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18±2.7 and 2±1 MJ/(m2•d),669 and 0 J/(cm2•h) during the observation period. |
| ------------------------------------------------------------------------------------------ |
 Sap flow response of Eucaylyptus （Eucalyptusurophylla） to environmental stress in South China. pdf |
