About Us | Help Videos | Contact Us | Subscriptions
 

Vadose Zone Journal Abstract - Original Research

Macroscopic Modeling of Plant Water Uptake in a Forest Stand Involving Root-Mediated Soil Water Redistribution

  VZJ Banner

This article in VZJ

  1. Vol. 12 No. 1
     
    Received: Oct 16, 2012
    Published: February 15, 2013


    * Corresponding author(s): vogel@fsv.cvut.cz
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2136/vzj2012.0154
  1. Tomas Vogel ,
  2. Michal Dohnala,
  3. Jaromir Duseka,
  4. Jana Votrubovaa and
  5. Miroslav Tesarb
  1. Faculty of Civil Engineering, Czech Technical University in Prague, Prague, Czech Republic
    Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Abstract

A dual-continuum model of soil-moisture dynamics that incorporates water uptake by plants via a mechanism driven by a difference in water potential is presented. The model is used to predict the root-mediated redistribution of water in a forest soil and compared with extensive field measurements.

One of the principal components of mass exchange within the soil−plant−atmosphere system is soil water extraction by plant roots. Adequate evaluation of water extraction is a prerequisite for correct predictions of plant transpiration and soil water distribution in the root zone. The main objective of the present study is to contribute to the development of sufficiently realistic, yet algorithmically simple models of water exchange between soil and plant roots applicable for numerical simulation of soil water responses to atmospheric forcing. In our case, a simple macroscopic, vertically distributed plant root water uptake approximation based on a traditional water-potential-gradient (WPG) formulation was adopted and implemented in a one-dimensional dual-continuum model of soil water flow based on the Richards’ equation. This combined model was used to simulate soil water movement at a forested site. The results were compared with observations (sap flow, soil water pressure, and soil water content) as well as with simulations produced using the standard semi-empirical model of Feddes. Principal aspects of the WPG prediction, such as root-mediated soil water redistribution, compensation for local water scarcity, and transpiration reduction, are exposed and discussed.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2013. Copyright © by the Soil Science Society of America, Inc.