From Sedona, we travelled about 240 miles south to Tucson and stayed there in a very nice campground in the Catalina State Park. Driving off the Colorado Plateau in southern direction, both climate and vegetation change slowly. Here is where the Sonoran Desert begins that extends over a large area in the southeast corner of the US and into northeastern Mexico. But only in a very limited part of the Sonoran – around Tucson – do the majestic Saguaro cacti grow (pronounced like ‘Swhaaro’), namesake of a national park that is located to the east and west of Tucson. This national park was the main reason why we came to the area.
North of Tucson is Biosphere 2, an Earth system science research facility that was constructed in the late 70s as a large, enclosed “greenhouse” to study the feasibility of humans living off of farming without exchanging food, oxygen, carbon dioxide and waste with the external world. From 1981 to 1983, 8 people lived here in complete encapsulation (heating and cooling was accomplished from the outside by heat exchangers without cross-exchange of any matter). Oxygen production (and carbon dioxide consumption) was handled by plants that grew in five different “bioms”: rain forest, ocean, mangrove wetland, savannah, and fog desert, in addition to the agricultural area that provided food for the inhabitants. The enclosed area of Biosphere 2 is over 3 acres (12.000 qm).
The ‘pyramid’ on the right picture houses the rain forest, pictured below.
The rain forest
The fog desert
The “landmark” of the Sonoran Desert:
…and up to 200 years old.
Saguaros can be 40-50 ft (12-15 m) tall…
Another beautiful cactus is the Fish Hook Barrel (also dubbed “mother-in-law seat”)
A fruit bearing mother-in-law seat
The Sonoran Desert is one of my most favorite landscapes