Cactus of South Mountain Park

Parts of a Saguaro Cactus

Quantitative Observations Temperature of Cacti in South Mountain Park 5:30 p.m.

Cactus #1 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 103.2 SPINE IN SUN 92.9 PLEAT IN SHADE 86.0 SPINE IN SHADE 83.1

Cactus #1

Cactus #2 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 98.2 SPINE IN SUN 92.1 PLEAT IN SHADE 88.0 SPINE IN SHADE 84.6

Cactus #3 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 101.9 SPINE IN SUN 96.45 PLEAT IN SHADE 86.1 SPINE IN SHADE 85.7

Cactus #4 83.3 F° LOCATION ON CACTUS TEMP F° PLEAT IN SUN 104.4 SPINE IN SUN 102.7 PLEAT IN SHADE 85.3 SPINE IN SHADE 83.6 83.3 F°

Cactus #5 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 98.5 SPINE IN SUN 93.9 PLEAT IN SHADE 93.3 SPINE IN SHADE 90.5

Cactus #6 83.3 F° LOCATION ON CACTUS TEMP F° PLEAT IN SUN 101.5 SPINE IN SUN 99.7 PLEAT IN SHADE 83.5 SPINE IN SHADE 83.1 83.3 F°

Cactus #7 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 99.5 SPINE IN SUN 97.4 PLEAT IN SHADE 83.3 SPINE IN SHADE 81.7

Cactus #8 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 104.0 SPINE IN SUN 97.9 PLEAT IN SHADE 101.5 SPINE IN SHADE 93.9 LOCATION ON CACTUS TEMP F° PLEAT IN SUN SPINE IN SUN PLEAT IN SHADE SPINE IN SHADE

Cactus #9 LOCATION ON CACTUS TEMP F° PLEAT IN SUN 112.4 SPINE IN SUN 104.4 PLEAT IN SHADE 100.5 SPINE IN SHADE 97.2

Qualitative Observations The cacti do not grow close to each other The pleats were closer together on the west and east sides of the cactus; the pleats were farther apart on the north and south side Barrel cactus that were in the sun were almost completely covered in spines Barrel cactus that were in the shade had very few spines

Observing Sketch 3 different cacti from today. Use color. Notice the differences as you sketch. Write notes as you sketch. Think as you sketch – Why are the cacti in the shape that they are? Use the flashlights to model the sun’s rays throughout the day. What do you notice as the sun moves? Why are they designed that way? Where do cacti live?

Questions to answer on poster: What are some of the adaptations that the saguaro cactus has to help it survive the desert heat and low water supply? What are the 2 functions of the pleats? What are the 2 functions of the spines? How does the temperature of the cactus vary when in the shade and in the sun? How much of the cactus is in the shade at any given time? Do you think saguaro cacti could live somewhere other than the desert? Why or why not? Design Challenge: Sketch a bioengineered structure inspired by the cactus that would keep cool in the desert heat.