D. Ground squirrels and kangaroo rats aerate the soil for the cacti by digging elaborate networks of tunnels and chambers in the ground. Cacti serve the desert and its living organisms even in death. A. Withered stems of dead cacti fall and enrich the desert soil. B. Large skeletons of dead saguaros shade new cacti growth. C. Dead saguaros are homes to termites, scorpions, spiders, and Gila monsters.
People have many uses for cacti of their own.
A. Nourishing opuntia fruits are a staple food of Indians in North and South America. B. Mexicans make preserves and alcoholic beverages out of cacti's fruit and berries. C. Indians of the Southwest produce sweet candy from cacti juice. D. Cacti stems are used as lumber to make floors, walls, beams, furniture, and doorsills in Central and South America. E. Papago people of the Southwest use the ribs of giant cacti for making roofs, cradles, and small items for tourist trade.