Do Models Established In The 1980S Accurately Predict Flowering For Five Sonoran Plant Species Under Current Conditions Of Drought And Warmer Average Temperatures?
Presenter: Dylan Girone1
Co-Author(s): Ava Lasater, Nick McFarlin, Brandolyn Baeza, Eden Harper, James O’Neil, Dylan Simpson, Cassidy Chang
Advisor(s): Dr. Martha Whitaker and Dr. Theresa Crimmins
1Department of Hydrology and Atmospheric Sciences, University of Arizona
Arizona is currently the fourth-fastest warming state in the country based on warming rates observed since 1970 (States at Risk). There is also a very intense trend toward increased drought in the US Southwest, which may already have drifted into a drier climate state (Prein et al., 2016). Given the conditions of ongoing drought and warmer temperatures over the past few decades, we intend to document the flowering behavior of five Sonoran Desert plants and assess whether drought and warming trends might be affecting the timing of flowering. These five plants are: Larrea (creosote); F. splendens (ocotillo); E. farinosa (brittlebush); A. constricta (whitethorn acacia); and Cercidium microphyllum (yellow palo verde). We used gridded precipitation and temperature data from the PRISM Climate database to define pre-determined models (Bowers and Dimmitt (B&D), 1994) of flowering triggers for the five species. Observations of flowering timing were obtained from the USA National Phenology Network’s (NPN) database for numerous Arizona locations. We recreated the Bowers and Dimmitt models in Python to evaluate how well the models predicted NPN’s Nature’s Notebook flowering onset data. Preliminary results indicate that flowering occurred earlier than predicted by B&D’s model: brittlebush by ~90 days; creosote by 42 days; acacia by 26 days; and ocotillo by 12 days. Further results from our comparison studies will be presented in our poster.