干旱区生态环境知识资源中心(Arid): Radial profile of sap flow velocity in mature Xinjiang poplar(Populus alba L. var. pyramidalis) in Northwest China

Arid

	Radial profile of sap flow velocity in mature Xinjiang poplar(Populus alba L. var. pyramidalis) in Northwest China
	Dang Hongzhong; Zha Tianshan; Zhang Jinsong; Li Wei; Liu Shizeng
来源期刊	Journal of Arid Land
ISSN	1674-6767
出版年	2014
卷号	6 期号:5 页码:612-627
英文摘要	Estimation of the transpiration rate for a tree is generally based on sap flow measurements within the hydro-active stem xylem. In this study, radial variation of sap flow velocity(J_s) was investigated at five depths of the xylem(1, 2, 3, 5 and 8 cm under the cambium) in three mature Xinjiang poplar(Populus alba L. var. pyramidalis) trees grown at the Gansu Minqin National Studies Station for Desert Steppe Ecosystem from May to October 2011. Thermal dissipation probes of various lengths manufactured according to the Granier's design were installed into each tree for simultaneous observation of the radial patterns of J_s through the xylem. The radial patterns were found to fit the four-parameter GaussAmp equation. The peak J_s was about 27.020.95 kg/(dm~2·d) at approximately 3 to 5 cm deep from the cambium of the three trees,and the lowest J_s appeared at 1 cm deep in most of the time. Approximately 50% of the total sap flow in Xinjiang poplar occurred within one-third of the xylem from its outer radius, whereas 90% of the total sap flow occurred within two-fifth of the xylem. In addition, the innermost point of the xylem(at 8-cm depth), which appeared as the penultimate sap flow in most cases during the study period, was hydro-active with J_s,8 of 7.553.83 kg/(dm~2·d). The radial pattern of J_s was found to be steeper in midday than in other time of the day, and steeper diurnal fluctuations were recorded in June, July and August(the mid-growing season). Maximum differences between the lowest J_s(J_(s,1) or J_(s,8)) and the highest J_s(J_(s,3) or J_(s,5)) from May through October were 12.41, 17.35, 16.30, 18.52, 12.60 and 16.04 g/(cm~2·h), respectively. The time-dependent changes of J_s along the radial profile(except at 1-cm depth) were strongly related to the reference evapotranspiration(ET_0). Due to significant radial variability of J_s, the mean daily sap flow at the whole-tree level could be over-estimated by up to 29.69% when only a single probe at depth of 2 cm was used. However, the accuracy of the estimation of sap flow in Xinjiang poplar could be significantly improved using a correction coefficient of 0.885.
英文关键词	sap flow radial pattern Populus alba L.var.pyramidalis reference evapotranspiration(ET_0) Granier method
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	CSCD
WOS研究方向	Forestry
CSCD记录号	CSCD:5203532
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335395
作者单位	Dang Hongzhong, Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China.; Li Wei, Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China.; Zha Tianshan, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.; Zhang Jinsong, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.; Liu Shizeng, Gansu Desert Control Research Institute, Lanzhou, Gansu 730070, China.
推荐引用方式 GB/T 7714	Dang Hongzhong,Zha Tianshan,Zhang Jinsong,et al. Radial profile of sap flow velocity in mature Xinjiang poplar(Populus alba L. var. pyramidalis) in Northwest China[J],2014,6(5):612-627.
APA	Dang Hongzhong,Zha Tianshan,Zhang Jinsong,Li Wei,&Liu Shizeng.(2014).Radial profile of sap flow velocity in mature Xinjiang poplar(Populus alba L. var. pyramidalis) in Northwest China.Journal of Arid Land,6(5),612-627.
MLA	Dang Hongzhong,et al."Radial profile of sap flow velocity in mature Xinjiang poplar(Populus alba L. var. pyramidalis) in Northwest China".Journal of Arid Land 6.5(2014):612-627.