DO3SE modelling of soil moisture to determine ozone flux to forest trees
Journal article, 2012

The DO3SE (Deposition of O-3 for Stomatal Exchange) model is an established tool for estimating ozone (O-3) deposition, stomatal flux and impacts to a variety of vegetation types across Europe. It has been embedded within the EMEP (European Monitoring and Evaluation Programme) photochemical model to provide a policy tool capable of relating the flux-based risk of vegetation damage to O-3 precursor emission scenarios for use in policy formulation. A key limitation of regional flux-based risk assessments has been the assumption that soil water deficits are not limiting O-3 flux due to the unavailability of evaluated methods for modelling soil water deficits and their influence on stomatal conductance (g(sto)), and subsequent O-3 flux. This paper describes the development and evaluation of a method to estimate soil moisture status and its influence on g(sto) for a variety of forest tree species. This DO3SE soil moisture module uses the Penman-Monteith energy balance method to drive water cycling through the soil-plant-atmosphere system and empirical data describing g(sto) relationships with pre-dawn leaf water status to estimate the biological control of transpiration. We trial four different methods to estimate this biological control of the transpiration stream, which vary from simple methods that relate soil water content or potential directly to g(sto), to more complex methods that incorporate hydraulic resistance and plant capacitance that control water flow through the plant system. These methods are evaluated against field data describing a variety of soil water variables, g(sto) and transpiration data for Norway spruce (Picea abies), Scots pine (Pinus sylvestris), birch (Betula pendula), aspen (Populus tremuloides), beech (Fagus sylvatica) and holm oak (Quercus ilex) collected from ten sites across Europe and North America. Modelled estimates of these variables show consistency with observed data when applying the simple empirical methods, with the timing and magnitude of soil drying events being captured well across all sites and reductions in transpiration with the onset of drought being predicted with reasonable accuracy. The more complex methods, which incorporate hydraulic resistance and plant capacitance, perform less well, with predicted drying cycles consistently underestimating the rate and magnitude of water loss from the soil. A sensitivity analysis showed that model performance was strongly dependent upon the local parameterisation of key model drivers such as the maximum g(sto), soil texture, root depth and leaf area index. The results suggest that the simple modelling methods that relate g(sto) directly to soil water content and potential provide adequate estimates of soil moisture and influence on g(sto) such that they are suitable to be used to assess the potential risk posed by O-3 to forest trees across Europe.

plant-atmosphere interaction

holm oak forest

stomatal conductance

picea-abies l

free-air fumigation

southern appalachian forest

quercus-ilex l

leaf gas-exchange

beech fagus-sylvatica

forests

aspen-birch

Author

P. Buker

University of York

T. Morrissey

University of York

A. Briolat

University of York

R. Falk

University of York

David Simpson

Chalmers, Earth and Space Sciences, Onsala Space Observatory

J. P. Tuovinen

Finnish Meteorological Institute (FMI)

R. Alonso

Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (Ciemat)

Sabine Barth

University of Gothenburg

M. Baumgarten

Technical University of Munich

N. Grulke

USDA Forest Service Pacific Northwest Research Station

P. E. Karlsson

IVL Swedish Environmental Research Institute

J. King

University of Antwerp

North Carolina State University

F. Lagergren

Lund University

R. Matyssek

Technical University of Munich

A. Nunn

Technical University of Munich

R. Ogaya

CREAF - Centre de Recerca Ecològica i Aplicacions Forestals

J. Penuelas

CREAF - Centre de Recerca Ecològica i Aplicacions Forestals

L. Rhea

North Carolina State University

M. Schaub

Eidgenossische Forschungsanstalt fur Wald, Schnee Und Landschaft Eth-Bereichs

Johan Uddling

University of Gothenburg

W. Werner

University of Trier

L. Emberson

University of York

Atmospheric Chemistry and Physics

1680-7316 (ISSN) 1680-7324 (eISSN)

Vol. 12 12 5537-5562

Driving Forces

Sustainable development

Subject Categories

Meteorology and Atmospheric Sciences

Biological Sciences

Earth and Related Environmental Sciences

Climate Research

Roots

Basic sciences

DOI

10.5194/acp-12-5537-2012

More information

Latest update

7/29/2019