Research Interests-Southwestern Desert

Distribution of Saguaro cactus and their nurse plants 

Saguaro cactus and its creosote bush nurse plant.

Organ Pipe Cactus National Monument, AZ. May 2006 

My desert research centers on the distribution and composition of the Saguaro-nurse plant relationship. In the harsh desert climates, there need for protection against sun, wind, and drought. Nurse plants provide shade, nutrients, and water to emerging juvenile cacti. Over time, Saguaro will outcompete their nurses and eventually excluding their nurse. Students from my SLU Desert Ecology class  and I observed a trend of creosote bush and triangle-leaf bursage nursing Saguaros. In the early morning, these bushes create a  warming microclimate about the cactus, buffering them from the radiational cooling of the evening-early morning. As the daytime temperature increases, nurse plants shade the growing Saguaro protecting them from scorching UV rays. Currently, we are pursuing other metrics such as height and dbh as a function of nurse as well as angle of Saguaro to nurse.

Dayna Garneau en route to the nearest nursing Saguaro.

                                              Saguaro being nursed by an ironwood tree.

Nursing Saguaro under the shade of a Palo verde.

Gilbert Ray campground, Tucson, AZ. May 2006.