California has been in a severe drought in recent years due to anthropogenic warming, and it has had a major effect on chemical and physical properties of native plants. Salvia leucophylla, a common plant in Southern California, has evolved an adaptation to water stress through losing its leaves, known as a drought deciduous plant. Considering the increase of CO2 in the atmosphere, it is absolutely essential for leaves to retain their ability to photosynthesize to maintain the health of the environment through CO2 sequestration. The objective of this experiment was to see how drought levels affect the physical and chemical properties of Salvia leucophylla, also known as purple sage. Our prediction is that drought conditions will compromise the plant’s photosynthetic rate and stomatal conductance. We investigated this issue by creating three treatments: a control watered every other day, and two manipulated groups watered weekly and none at all. After two weeks, we measured the photosynthetic rate, stomatal conductance, ETR, qN and qP, Fv’/Fm’, and leaf temperature. Our results showed that there was a significant decrease of photosynthetic rate (p<0.0001), stomatal conductance (p=0.00239), and electron transport rate (p<0.0001) in the experimental plants. Thus, we were able to demonstrate the detrimental effects of drought conditions on native plants, providing evidence to the harmful consequences of climate change on plant function.
Scott, Brianna; Ordog, Theadora; and Lordi, Alexis, "The Effect of Water Deficit on Photosynthetic Properties of Salvia leucophylla" (2016). Pepperdine University, Featured Research. Paper 197.