Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.
(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)
Characterization of ambient ozone uptake and development of foliar injury models from a plant physiological ecology perspective
Abstract
A biologically-based secondary ambient air quality standard for vegetation in the U.S. is presently lacking. Analyses sensitive to the physiological conductivity of exposed plants as well as atmospheric and soil conditions were used here to predict the signature response of plants to ozone, foliar injury. Bel-W3 tobacco (Nicotiana tabacum L. cv. Bel-W3) was used as an acute-response model while Asclepias syriaca L. was used as a chronic-response model to identify important controlling factors involved in foliar injury response to ambient ozone. Temperature, RH, PAR, wind velocity, soil moisture, soil matric potential, and vapor pressure deficit were investigated relative to their influence on injury development during simultaneous exposure to ozone. Several important factors were found to lead to overestimation of vegetation exposure to ambient ozone. These included use of a standard ozone measurement height, soil moisture deficits, asynchrony between diurnal stomatal conductance and peak ozone concentration, episodic exposures to elevated ozone concentrations during late-day weak sunlight (PAR < 500), and seasonal decline of gas exchange and ozone uptake in herbaceous plants. These results indicate the need for refinement of current indices to protect vegetation, which, if based solely on ozone concentration, e.g. AOT40, SUM06, W126, will continue to lead to overestimation of ozone exposure.
Subject Area
Environmental science|Ecology|Botany
Recommended Citation
Bergweiler, Christopher James, "Characterization of ambient ozone uptake and development of foliar injury models from a plant physiological ecology perspective" (2001). Doctoral Dissertations Available from Proquest. AAI3012114.
https://scholarworks.umass.edu/dissertations/AAI3012114