Physical and Environmental Geography Commons^™

Nurse Rock Microclimates Significantly Buffer Exposure To Freezing T Temperature And Moderate Summer Temperature, Joshua L. Conver, Elliott Yarwood, Lucas D. Hetherington, Don E. Swann

United States National Park Service: Publications

Nurse tree canopies mitigate exposure to freezing temperatures that could result in injury or mortality to the saguaro cactus (Carnegiea gigantea). Abiotic objects have been hypothesized to provide similar beneficial microclimates. We used data loggers at 11 nurse rock sites to record daily daytime summer maximum and winter nighttime minimum temperatures at Saguaro National Park, Arizona, to examine the effectiveness of rocks to moderate seasonal temperature extremes in the microclimate. Temperatures at rock sites averaged 2 °C warmer than exposed open control sites in winter. We found that the efficiency of rocks to act as insulators significantly increased as temperature …