1. Cactus of South Mountain Park

2. Parts of a Saguaro Cactus

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

4. 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

5. Cactus #1

6. 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

7. 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

8. 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°

9. 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

10. 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°

11. 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

12. 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

13. 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

14. 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

15. 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?

16. 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.