Impact of stem water storage on diurnal estimates of whole-tree transpiration and canopy conductance from sap flow measurements in Japanese cedar and Japanese cypress trees

<p>Trees in arid and semi-arid regions are faced with water shortages at most times, and the use of water storage in tree stem is an important mechanism and pathway for adaptation to drought. In this research, we have explored the tree saplings in semi-arid areas by continuous monitoring and analysis of the sap flux at stem top and stem breast, in the main growth season. A primary objective is to find out when and how trees use stem water storage as a reservoir, and more specifically if there is a difference in stem flow start time between stem top and stem breast. Our study shows that in sunny day of the growing season, the sap flow at stem top start time is later than the sap flow at stem breast, with the maximum of time lag about 60 mins, and the daily sap flow peak time of stem top is later than that of the stem breast by 1-2 hrs. The maximum daily flux at stem top is about 1.4-2.1 times greater than that at stem breast. Stem water storage increases the drought tolerance of trees. The depletion stage of stem water storage mainly occurs in early morning, and then enters the replenishing phase in the afternoon. In a sunny day, with the increase of soil water deficit with relative extractable water (REW) (or the relative effective soil water index) less than 0.43, demand for water storage of stem is more significant, and its role is mainly based on the depletion process. When the soil moisture condition is improved, the process is dominated by replenishing. From the results of continuous observations throughout the growing season, the depleting and replenishing processes can achieve equilibrium in a short period of time (like a few days). This research has advanced our understanding of the utilization mechanism of tree stem storage water in semi-arid areas.</p>

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Estimation of canopy water storage capacity from sap flow measurements in a Bornean tropical rainforest

Journal of Hydrology ◽

10.1016/j.jhydrol.2008.01.020 ◽

2008 ◽

Vol 352 (3-4) ◽

pp. 288-295 ◽

Cited By ~ 14

Author(s):

Tomonori Kume ◽

Odair J. Manfroi ◽

Koichiro Kuraji ◽

Nobuaki Tanaka ◽

Toshinobu Horiuchi ◽

...

Keyword(s):

Sap Flow ◽

Tropical Rainforest ◽

Storage Capacity ◽

Water Storage ◽

Flow Measurements ◽

Water Storage Capacity ◽

Sap Flow Measurements ◽

Canopy Water

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Sap flow index as an indicator of water storage use

Journal of Hydrology and Hydromechanics ◽

10.1515/johh-2015-0013 ◽

2015 ◽

Vol 63 (2) ◽

pp. 124-133 ◽

Cited By ~ 4

Author(s):

Nadezhda Nadezhdina ◽

Jan Čermák ◽

Alec Downey ◽

Valeriy Nadezhdin ◽

Martti Perämäki ◽

...

Keyword(s):

Sap Flow ◽

Water Storage ◽

Relative Magnitude ◽

Continuous Heating ◽

Flow Index ◽

Oak Trees ◽

Picea Omorika ◽

Stem Water ◽

Stem Water Storage ◽

Daily Transpiration

Abstract Symmetrical temperature difference also known as the sap flow index (SFI) forms the basis of the Heat Field Deformation sap flow measurement and is simultaneously collected whilst measuring the sap flow. SFI can also be measured by any sap flow method applying internal continuous heating through the additional installation of an axial differential thermocouple equidistantly around a heater. In earlier research on apple trees SFI was found to be an informative parameter for tree physiological studies, namely for assessing the contribution of stem water storage to daily transpiration. The studies presented in this work are based on the comparative monitoring of SFI and diameter in stems of different species (Pseudotsuga menziesii, Picea omorika, Pinus sylvestris) and tree sizes. The ability of SFI to follow the patterns of daily stem water storage use was empirically confirmed by our data. Additionally, as the HFD multipointsensors can measure sap flow at several stem sapwood depths, their use allowed to analyze the use of stored water in different xylem layers through SFI records. Radial and circumferential monitoring of SFI on large cork oak trees provided insight into the relative magnitude and timing of the contribution of water stored in different sapwood layers or stem sectors to transpiration.

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Observations of stem water storage in trees of opposing hydraulic strategies

Ecosphere ◽

10.1890/es15-00170.1 ◽

2015 ◽

Vol 6 (9) ◽

pp. art165 ◽

Cited By ~ 38

Author(s):

Ashley M. Matheny ◽

Gil Bohrer ◽

Steven R. Garrity ◽

Timothy H. Morin ◽

Cecil J. Howard ◽

...

Keyword(s):

Water Storage ◽

Stem Water ◽

Stem Water Storage

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Effects of size and microclimate on whole-tree water use and hydraulic regulation inSchima superbatrees

PeerJ ◽

10.7717/peerj.5164 ◽

2018 ◽

Vol 6 ◽

pp. e5164

Author(s):

Xiao-wei Zhao ◽

Lei Ouyang ◽

Ping Zhao ◽

Chun-fang Zhang

Keyword(s):

Water Use ◽

Water Consumption ◽

Large Scale ◽

Hydraulic Conductance ◽

Canopy Conductance ◽

Wet Season ◽

Sap Flux Density ◽

Tree Water Use ◽

Tree Transpiration ◽

Whole Tree

BackgroundPlant-water relations have been of significant concern in forestry and ecology studies in recent years, yet studies investigating the annual differences in the characteristics of inter-class water consumption in trees are scarce.MethodsWe classified 15 trees from aSchima superbaplantation in subtropical South China into four ranks using diameter at breast height (DBH). The inter-class and whole-tree water use were compared based on three parameters: sap flux density, whole-tree transpiration and canopy transpiration over two years. Inter-class hydraulic parameters, such as leaf water potential, stomatal conductance, hydraulic conductance, and canopy conductance were also compared.Results(1) Mean water consumption of the plantation was 287.6 mm over a year, 165.9 mm in the wet season, and 121.7 mm in the dry season. Annual mean daily water use was 0.79 mm d−1, with a maximum of 1.39 mm d−1. (2) Isohydrodynamic behavior were found inS. superba. (3) Transpiration was regulated via both hydraulic conductance and stoma; however, there was an annual difference in which predominantly regulated transpiration.DiscussionThis study quantified annual and seasonal water use of aS. superbaplantation and revealed the coordinated effect of stoma and hydraulic conductance on transpiration. These results provide information for large-scale afforestation and future water management.

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