The US’s biggest cactus is the Saguaro Cactus, towering at 40 feet and weighing up to 2 tons. These cacti are branch-like and covered in spines and can exclusively be found in the Sonoran Desert, which stretches across parts of southern Arizona, southeast California, and Western Sonora, Mexico. These plants serve as a keystone species and desert indicator, offering food and shelter for countless animals.
Back in 1994, the Saguaro National Park was created to protect the beautiful landscapes of the Sonoran Desert, found in Tucson, Arizona. This park is crucial for the growth of the iconic Saguaro Cactus. It is divided into two districts, located in the eastern and western regions of Tucson, and together, they span across 91,327 acres.
When Saguaro cacti first begin to grow, they have a clever strategy for protecting themselves. They use what’s called “nurse trees” to provide shelter. These trees – usually fast-growing types like palo verde, ironwood, and mesquite – give the slower-growing cacti a chance to get established. But as the cactus grows larger, it starts to compete with the nurse tree for resources like water and nutrients. Eventually, the nurse tree will die off, but by then the Saguaro cactus will be strong enough to survive on its own.
The Saguaro Cactus is a plant that grows slowly and can take many years to reach its towering height. It usually takes about 70 long years for the cactus to grow to a height of six feet. Interestingly, the iconic branches of the cactus only begin to appear when it’s approximately 95-100 years old and about 15-16 feet tall. Upon reaching 125 years, the Saguaro Cactus is considered an adult and can have multiple or no branches at all. While experts suggest that these cacti can live for about 150-175 years on average, some may even live up to 200 years.
Although the Saguaro Cactus’s taproot extends around five feet into the soil, the plant’s root system is quite shallow. The roots are only 3-5 inches deep, but they spread out wide in a radius as long as the plant is tall. The taproot’s primary function is to access underground water that sustains the plant in the desert. The cactus’s main roots are covered with specialized hairs that can collect up to 200 gallons of water during a single rainfall. The summer monsoons in the Sonoran Desert are generally brief, so the widespread network of the Saguaro’s root system helps absorb water quickly, preventing any runoff. The stored water is then used to keep the plant hydrated during dry periods in the desert. Additionally, the extended root system also helps support the cactus, keeping it upright during windy rainstorms.
The Saguaro Cactus blooms during late spring to early summer, producing white flowers that attract multiple bat species that serve as pollinators. These bats feed on the nectar produced by the flowers and also eat the fruit, thus dispersing the seeds.
The Saguaro Cactus serves as both a plant and a sanctuary for various animals. Among these animals is the Gila Woodpecker, which creates holes in the cactus to make nesting sites. Other birds such as elf owls, screech owls, purple martins, finches, and sparrows also inhabit abandoned cavities within the cactus. Moreover, Harris’s Hawk constructs its nests in the arms of the Saguaro Cactus. Bobcats, also known as Lynx rufus, have padded paws that allow them to climb the cactus without getting hurt by the spiky spines that can grow up to three inches long. The height of the cactus also provides an advantageous vantage point for bobcats to observe the surrounding terrain.
The Saguaro Cactus is more than just a plant, it’s a sanctuary for various animals. One of them being the Gila Woodpecker, who excavates holes in the cactus for nesting sites. These cavities provide a safe haven from predators and shelter during colder times. Additionally, other birds such as elf owls, screech owls, purple martins, finches, and sparrows also use these empty cavities within the cactus. Moreover, the Harris’s Hawk constructs its nests on the arms of the Saguaro Cactus.
The saguaro cactus is not only a natural wonder, but also a safe haven for bobcats looking to escape predators. Bobcats, or Lynx rufus, have unique padded paws that allow them to climb the cactus without getting pricked by the three-inch-long spines. Furthermore, the towering height of the cactus gives the bobcat an excellent vantage point to observe its surroundings.
