Hydraulic resistance partitioning between shoot and root system and plant water status of Haloxyolon ammodendron growing at sites of contrasting soil texture
GuiQing XU, Yan LI, Ting ZOU
1 Fukang Station of Desert Ecology and Key Laboratory of Oasis Ecology and Desert Environment, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Hydraulic resistance partitioning between shoot and root system and plant water status of Haloxyolon ammodendron growing at sites of contrasting soil texture
GuiQing XU, Yan LI, Ting ZOU
1 Fukang Station of Desert Ecology and Key Laboratory of Oasis Ecology and Desert Environment, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
摘要 Hydraulic resistance components and water relations were studied on Haloxyolon ammodendron, a small xeric tree, growing at sites significantly differed in soil texture. Soil water content, leaf water potential (ψl), xylem water potential (ψx), root water potential (ψroot), leaf transpiration rate (TR) and stomatal conductance (gs) were measured at the two sites during the growing season of 2005 and 2006. Leaf specific hydraulic resistance (Rplant) during the whole growing season, hydraulic resistance of plants (Rp), shoots (Rshoot) and roots (Rroot) in the August of both years were calculated and expressed on leaf area basis. The results showed the proportion of the hydraulic resistance of the aerial part (Rshoot) to the Rp was the same to the proportion of the hydraulic resistance of the soil part (Rroot) to the Rp, indicating that both parts were equivalent important to plant water hydraulic system from soil to leaf. Positive significant correlations were found between Rp and Rroot, suggesting that root hydraulics resistance was a major determinant of plant hydraulic resistance (Rp) and transpiration rate. The integrated effect of stomatal control, hydraulic regulation and morphology adjustment enabled plants at heavy soil site surviving the extreme water deficit period.
Abstract: Hydraulic resistance components and water relations were studied on Haloxyolon ammodendron, a small xeric tree, growing at sites significantly differed in soil texture. Soil water content, leaf water potential (ψl), xylem water potential (ψx), root water potential (ψroot), leaf transpiration rate (TR) and stomatal conductance (gs) were measured at the two sites during the growing season of 2005 and 2006. Leaf specific hydraulic resistance (Rplant) during the whole growing season, hydraulic resistance of plants (Rp), shoots (Rshoot) and roots (Rroot) in the August of both years were calculated and expressed on leaf area basis. The results showed the proportion of the hydraulic resistance of the aerial part (Rshoot) to the Rp was the same to the proportion of the hydraulic resistance of the soil part (Rroot) to the Rp, indicating that both parts were equivalent important to plant water hydraulic system from soil to leaf. Positive significant correlations were found between Rp and Rroot, suggesting that root hydraulics resistance was a major determinant of plant hydraulic resistance (Rp) and transpiration rate. The integrated effect of stomatal control, hydraulic regulation and morphology adjustment enabled plants at heavy soil site surviving the extreme water deficit period.
基金资助: National Natural Science Foundation of China (40971042); Western Light project of the Chinese Academy of Sciences (XBBS 200808)
通讯作者:
Yan LI
E-mail: Liyan@ms.xjb.ac.cn
引用本文:
GuiQing XU, Yan LI, Ting ZOU. Hydraulic resistance partitioning between shoot and root system and plant water status of Haloxyolon ammodendron growing at sites of contrasting soil texture[J]. 干旱区科学, 10.3724/SP.J.1227.2010.00098.
GuiQing XU, Yan LI, Ting ZOU. Hydraulic resistance partitioning between shoot and root system and plant water status of Haloxyolon ammodendron growing at sites of contrasting soil texture. Journal of Arid Land, 2010, 2(2): 98-106.
