Abstract
Bamboo species—the only herbaceous trees—have unique structural and physiological characteristics that differ from those of other tree taxa. However, the role of night-time water use in bamboo is poorly understood and has rarely been investigated. We studied the day- and night-time sap flow response to culm age and rhizome structure in three age levels (juvenile, mature, and senescent) of Phyllostachys pubescens growing in the Nankun Mountain Natural Reserve, South China. We found that sap flow density and whole-tree hydraulic conductance decreased with culm age. After cutting of rhizome, the day-time sap flow and night-time water recharge decreased obviously. In addition, night-time water recharge accounted for the largest proportion (up to 30%) of total daily transpiration in normal senescent bamboos. Therefore, our study indicates that the connected rhizome system and night-time water recharge played a significant role in water compensation during the day and at night in bamboos. Night-time water recharge is especially critical to senescent bamboos, given their weaker transpiration due to the lower whole-tree hydraulic conductance, and consequently, they are more dependent on night-time water recharge for fulfilling their whole-day water consumption needs.
Highlights
Night-time water recharge in tree trunks accounts for ∼10–50% of the total daily transpiration of a plant (Loustau et al, 1996; Goldstein et al, 1998; Steppe and Lemeur, 2004; Scholz et al, 2008; Carrasco et al, 2014)
Day- and night-time Js were higher in the wet season than in the dry season during both day and night (Figure 2)
Both day- and nighttime Js decreased with increasing culm age and after rhizome cutting in the wet season, which showed that the night-time water recharge is affected by culm age and rhizome
Summary
Night-time water recharge in tree trunks accounts for ∼10–50% of the total daily transpiration of a plant (Loustau et al, 1996; Goldstein et al, 1998; Steppe and Lemeur, 2004; Scholz et al, 2008; Carrasco et al, 2014) It plays an important role in relieving xylem hydraulic stress and controlling fluctuations in leaf water potential, in addition to regulating the stomatal openings and water status (Cermák et al, 2007; Meinzer et al, 2008). Nighttime sap flow ameliorates the water lost from water-storage tissues due to daily transpiration, and enhances nitrogen uptake (Kupper et al, 2012; Rohula et al, 2014).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
