The use of transfer function models to describe the relationship between pollutant exposure and leaf stomatal opening

Abstract

Gas flux into plant leaves is regulated, in part, by stomatal opening and closing. Research has shown that stomatal responses can be influenced by exposure to gaseous pollutants. Measurements of stomatal response at a few fixed times have been tabulated, but models of stomatal response to pollutants over time have not been fully developed. Box-Jenkins time series models may be useful in describing the relationship between pollutant flux and stomatal aperture over time. Transfer function models (multivariate time series) can be used to relate input time series (pollutant load) and output time series (stomatal response). A basic description of time series and transfer function analysis is presented. Experimental considerations are also discussed. An example is presented using transfer function models to relate ozone fumigation of sunflower to changes in leaf temperature, used as a surrogate for stomatal responses to ozone.