Use of sap flow measurements to validate stomatal functions for mature beech (Fagus sylvatica) in view of ozone uptake calculations |
| |
Authors: | Sabine Braun Christian Schindler |
| |
Institution: | a Institute for Applied Plant Biology, Sangrubenstrasse 25, CH-4124 Schönenbuch, Switzerland b Swiss Tropical and Public Health Institute, University of Basel, Socinstrasse 57, CH-4051 Basel, Switzerland c Forest Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Universitätsstr. 16, 8092 Zürich, Switzerland |
| |
Abstract: | For a quantitative estimate of the ozone effect on vegetation reliable models for ozone uptake through the stomata are needed. Because of the analogy of ozone uptake and transpiration it is possible to utilize measurements of water loss such as sap flow for quantification of ozone uptake. This technique was applied in three beech (Fagus sylvatica) stands in Switzerland. A canopy conductance was calculated from sap flow velocity and normalized to values between 0 and 1. It represents mainly stomatal conductance as the boundary layer resistance in forests is usually small. Based on this relative conductance, stomatal functions to describe the dependence on light, temperature, vapour pressure deficit and soil moisture were derived using multivariate nonlinear regression. These functions were validated by comparison with conductance values directly estimated from sap flow. The results corroborate the current flux parameterization for beech used in the DO3SE model. |
| |
Keywords: | Ozone uptake Sap flow Stomatal conductance Fagus sylvatica DO3SE |
本文献已被 ScienceDirect 等数据库收录! |
|