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ארועים עתידיים

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סמינר צמח - דר יאיר מאו

תאריך: 
ד', 07/11/2018 - 12:00

מיקום: 
חדר 3114 בנין הדסה

 

Dr. Yair Mau

Department of Soil and Water sciences,
The Robert H Smith Faculty of Agriculture, Food and Environment

על

Plant hydraulics and the electric circuit analogue: modeling pitfalls and opportunities

כיבוד קל יוגש כרבע שעה לפני הסמינר

חברי סגל וסטודנטים המעוניינים להיפגש עם המרצה מתבקשים להתקשר עם תמר או שילה

ההרצאה תינתן באנגלית

Given in English

Plant hydraulics and the electric circuit analogue: modeling pitfalls and opportunities

Yair Mau, Gabriele Manoli and Avigail Kaner

We investigated the hydraulics of trees that rely on their internal water storage to maintain transpiration under high evaporative demand and dry soil conditions. Paying careful attention to commonly used hydraulic-based and electric-based modeling approaches, we found two main discrepancies in the way models based on the electric-circuit analogue describe plant hydraulics. First, the capacitor that represents the internal water storage should be grounded, instead of being connected in parallel with the xylem resistance (as often reported in the existing literature). Secondly, the water potential at the two extremes of the tree, e.g. soil and leaf water potentials ψS and ψL, should not be clustered as an effective difference water potentialΔψ=ψS-ψL, since that entails equal water fluxes at these two extremes (an assumption which is violated in the case of water storage). We present a minimal model that overcomes these limitations and, using the tools of system dynamics and simulations, analyze the different predictions it gives with respect to the traditional circuit model. The main differences are in thetree capabilities of filtering high-frequency external variations in water potential, and the time lag between the driving evaporative demand and the water fluxes. Our description of plant hydraulics is corroborated by measurements of tree water fluxes under varying levels of water stress. We show how this modeling framework can be easily extended to account for various tree branching architectures.