Sap flow response of Eucaylyptus (Eucalyptus urophylla) to environmental stress in South China  

Sap flow response of Eucaylyptus （Eucalyptus urophyila） to environmental stress in South China

作　　者：尹光彩 周国逸 MORRISJim 黄志宏 褚国伟 周光益 

机构地区：[1]SouthChinaBotanicGarden,CAS,Guangzhou510650,China [2]CentreforForestTreeTechnology,Victoria3084,Australia [3]ResearchInstituteofTropicalForestry,CAF,Guangzhou510520,China

出　　处：《Journal of Zhejiang University Science》2004年第10期1218-1225,共8页浙江大学学报（自然科学英文版）

基　　金：Project supported by Knowledge Innovation Funds from Chinese Academy of Sciences (Nos. KSCX2-SW-120, KZCX1-SW-01-01A3);;the Key Project of Guangdong Natural Science Foundation (No. 010567), China Author for correspondence

摘　　要：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 (>%) 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 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) (R^2=0.76, P=0.01 at Hetou and R^2=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=-17585X^3+15147X^2-1250.7X+2278.4 (R^2=0.68; P=0.01) at Hetou and Y=-101.67X^3-1.65X^2-376.4X+1914.8(R^2=0.40, P=0.05) at Jijia, where Ywas daily SFD, Xwas daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2kPa, within which daily SFD varied from 540±70L/(m^2·d) to 4739±115L/(m^2·d) at Hetou site, from 397±26L/(m^2·d) to 3414±191L/(m^2·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±1MJ/(m^2·d), 669 and 0J/(cm^2·h) during the observation period.

关 键 词：Sap flow Environmental stress Eucalyptus plantations Water conductivity 

分 类 号：S792.390.2[农业科学—林木遗传育种] TH133.37[农业科学—林学]