Divergences in hydraulic conductance and anatomical traits of stems and leaves in three temperate tree species coping with drought, N addition and their interactions. (20th December 2019)

• Record Type: Journal Article
• Authors: Zhang, Hongxia; McDowell, Nate G; Adams, Henry D; Wang, Anzhi; Wu, Jiabing; Jin, Changjie; Tian, Jinyuan; Zhu, Kai; Li, Weibin; Zhang, Yushu; Yuan, Fenghui; Guan, Dexin
• Is Part Of: Tree physiology. Volume 40:Number 2(2020)
• Page Start: 230
• Page End: 244
• Publication Date: 2019-12-20
• Subjects: drought stress -- hydraulic architecture -- hydraulic conductance -- N fertilization -- woody plants -- xylem embolism; Trees -- Physiology -- Periodicals; 582.16
• DOI: 10.1093/treephys/tpz135
• Languages: English
• ISSNs: 0829-318X

Abstract

Abstract: Drought and nitrogen (N) addition have been shown to affect tree hydraulic traits, but few studies have been made on their interactions across species with different wood types or leaf forms. We examined the responses of hydraulic conductance and xylem anatomical traits of Quercus mongolica (ring porous with simple leaves), Fraxinus mandshurica (ring porous with compound leaves) and Tilia amurensis (diffuse porous with simple leaves) to drought, N addition and their interactions. Drought stress decreased current-year xylem-specific conductivity in stems ( K sx ) and leaf hydraulic conductance ( K leaf ), but N addition affected K sx and K leaf differently among species and watering regimes. These divergent effects were associated with different responses of anatomical traits and leaf forms. Higher mean vessel diameter in stems and lower vessel density in leaves were observed with N addition. The three-way interactive effects of drought, N addition and tree species were significant for most values of anatomical traits. These results were also reflected in large differences in vessel diameter and density among species with different wood types or leaf forms. The two-way interactive effects of drought and N addition were significant on K leaf and predawn water potential, but not K sx, indicating that leaves were more sensitive than stems to a combination of drought stress and N addition. Our results provide mechanistic insight into the variable responses of xylem water transport to the interactions of drought and N availability.