Chaparral shrubs are known for their abilities to withstand dry environments. Both the California native C3 plant, Heteromeles arbutifolia, also known as Hollywood, and the CAM plant, Crassula ovata, also know as a Jade plant, have the ability to thrive under a Mediterranean-like climate region. However, during severe cases of drought one plant may better adapted than the other. The purpose of this experiment is to determine whether Heteromeles arbutifolia or Crassula ovata is better able to withstand drought by measuring the dehydration rate. We calculated the leaf-area to mass ratio and the change in water potential of each species by the use of a Scholander-Hammel Pressure Chamber and Leaf Area Meter. The Crassula ovata has a lower leaf area to mass ratio in comparison to Heteromeles arbutifolia, which demonstrates it can hold a greater volume of water. A Student paired T-test with a 95% confidence level was used to determine the significant difference between the dehydration rate of the Crassula ovata and Heteromeles arbutifolia. Based on our results, the dehydration rate per was higher for the Crassula ovata. This supports our initial hypothesis that the CAM plant is more drought tolerant than the C3 plant because the CAM plant had a lower change in water potential as a result of nocturnal stomata opening.
McNally, Monét; Yakupitiyage, Stephanie; and Lockhart, Jamille, "Measuring Water Potential Among Crassula ovata and Heteromeles arbutifolia" (2014). Pepperdine University, All Undergraduate Student Research. Paper 115.