In the Spring Semesters of 2016 and 2017, research was conducted on the relative fitness of Stipa pulchra in the transplant garden on the Drescher campus at Pepperdine University. The first study in 2016 examined the fitness of Stipa pulchra and Avena fatua in the transplant and wild gardens after a five year drought in California. In the results of this experiment, the hypothesis was supported when observing that the wild S. pulchra depicted higher fitness that the transplant S. pulchra in areas of stomatal conductance, height, water potential, percent sun and dark-adapted fluorescence. The second study in 2017 investigated the fitness of Stipa pulchra and A. fatua in the transplant and wild gardens after abnormally high rainfall in the winter season. The research found that the hypothesis was correct in that all of the plants had higher fitness than the plants examined in the 2016 research and that A. fatua had higher fitness than S. pulchra in both gardens in areas of stomatal conductance, height, dark-adapted fluorescence, and water potential. To further this study, this research was conducted the spring semester of 2019 to measure the fitness of S. pulchra in the transplant and wild garden and compared to the fitness of the invasive weed, A. fatua, post the Woolsey Fire of 2018. As S. pulchra is the state grass of California, it is important to understand the factors that affect its fitness levels.
Similar to many perennial bunch grasses, There is a lack of historical context of S. pulchra fitness in the occurrence of fire. However, many suppose that fire exclusion results in a decline of S. pulchra. The regeneration of S. pulchra after fire is increased in the absence of other annual grasses and invasive species (Steinberg 2002). At Pepperdine University, S. pulchra is in visible decline due to competition with A. fatua and human interference. It is hypothesized that S. pulchra will display more significant declines in the transplant garden than in the wild garden and that the increased competition with A. fatua will negatively affect the fitness of S. pulchra in both gardens. The results of this study show that there was no significant difference in the fitness of S. pulchra in the transplant compared to the wild garden as well as no significant difference in the fitness of A. fatua compared to S. pulchra.
Bonin, Ashley; Cook, Madison; and Head, Sara, "Comparative Fitness of Post-Fire Transplant Stipa Pulchra and Wild Stipa Pulchra in Competition with Avena Fatua" (2019). Pepperdine University, Featured Research. Paper 166.