The Effect of Riparian and Arid Environments on Stomatal Conductance in Baccharis salicifolia and Heteromeles arbutifolia

A riparian environment is characterized by higher moisture levels than an arid environment; therefore they have different species of plants that can adapt to their natural habitats. It is critical that we explore the characteristics plants have in relation to their native environments. We propose to test the hypothesis that Baccharis salicifolia would have a higher stomatal conductance rate to water vapor loss compared to Heteromeles arbutifolia because Baccharis salicifolia thrives in a riparian environment in which water abundance would increase stomatal opening thereby contributing to the greater conductance. Using the LI-6400, we measured the conductance rate, photosynthetic rate, CO2 levels internally, CO2 levels of the air, fluorescence, phi PSII, electron transport rate, and qP of Baccharis salicifolia and Heteromeles arbutifolia. Baccharis salicifolia is a riparian species found on the Pepperdine campus, while Heteromeles arbutifolia is an arid species also found on the Pepperdine campus. By comparing the parameters we measured, we were able to observe that Baccharis salicifolia does have a higher photosynthetic rate, conductance, fluorescence yield, electron transport rate, quantum yield, and photosynthetic quenching than Heteromeles arbutifolia because of the riparian habitat that it is found in