A stomatal ozone flux model

 

Assessment of a stomatal ozone flux model in Astronium graveolens Jacq

by Cassimiro J. C. (2015)

Instituto de Botânica. Secretaria do Meio Ambiente (São Paulo – Estado). São Paulo, SP, Brazil

Abstract
The concentrations of ozone (O3) have increased annually in both urban and rural areas, which can result in reduced agricultural productivity and damage to plant species, communities and ecosystems. It is necessary to know the O3-induced effects on plants to determine the concentration threshold that should not be overcome to ensure the protection of species and vegetation.

In Brazil there is no vegetation index of protection against the effects of this pollutant. The first indices used were based on averages of concentration or the sum of hourly concentrations and showed poor correlation with the plant responses. Currently the research has been focus on indices based on stomatal conductance.

This study aims to obtain data with Astronium graveolens Jacq., an O3-sensitive species to insert in a model of stomatal conductance flux of O3 and evaluate their applicability in our country. Seedlings of A. graveolens will be exposed for four three-month periods in contaminated site by O3. The weather conditions and the concentration of pollutants in the study area will be monitored continuously. Daily courses of stomatal conductance under various environmental conditions will be done weekly. The results will be applied to the model in which stomatal conductance is multiplied by the relative values of factors that modulate such as temperature, vapor pressure deficit, photosynthetically active radiation, ozone concentration and water content of the soil. The presence of foliar injury induced by O3 is used as the response variable. This study will obtain data that could support proposals for an index of tropical species protection against the effects of O3. (AU)