We stopped at the Rincon Mountain Visitor Center in the East Park first to pick up a map, view the movie about the park, and buy a patch (I still collect patches from the National Parks and plan to incorporate them into some project one day.)
Next, we followed the 8-mile Cactus Forest Drive through a dense cactus forest. It was surprisingly scenic, a landscape filled with a variety of cacti and desert shrubs, many in bloom. The tall stately saguaro dominated the landscape.
Saguaros are the symbol of the Sonoran Desert and inhabit only this desert. The Sonoran Desert covers 120,000 square miles (260,000 sq km), an area about the size of New Mexico, and is the most diverse desert in North America. Because winters are mostly frost-free, and there are two rainfall periods, one in winter and one in summer, it is home to over 4,000 species of plants and animals.
I learned that saguaros have been here for over 10,000 years and as some scientists suggest, either returned from an ice-age refuge or advanced as the climate warmed up. Although they have adapted well to their current conditions, saguaros still face many challenges. They must survive periods of cold and drought, and need to find nutrients to bear flowers and fruit with seeds for the next generation. Viable only for one summer, the seeds must have the summer rains and warm temperatures to germinate. These conditions need to continue for several consecutive years for the young saguaros to continue to establish and thrive. Ideally, a seed will begin life in good soil under the protection of a plant that can offer shade, protection from hard rain, and cover from being seen and eaten. It is quite common to see young saguaros growing up between branches of a palo verde tree, which in effect acts as a nurse tree to the growing cactus, just like like in the photo here. Eventually as the saguaro matures, a battle for the water source ensues between both plants, and typically the palo verde tree loses to the saguaro.
We learned from the movie that years ago when settlers began ranching here, the cattle trampled the new saguaro plants to the point where the population diminished greatly. Today, the saguaro is protected.
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| a young saguaro, surviving and thriving |
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| desert in bloom |
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| barrel cactus in bloom - these cacti always grow towards the sun, therefore lean towards the south, so are known as the "compass cactus" |
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| Tuscon Mountains in background, and me with a buckhorn cholla cactus |
The Saguaro is the tallest and largest cactus in the US, growing as high as 50 feet and weighing several tons. It can live to be 200 years old. I was surprised to see so many saguaro in the National Park without their recognizable iconic limbs, looking more like fuzzy, green branchless trunks. I found out that saguaro might produce their first arms at approximately 90 years of age. Growing arms is related to age but also dependent on water supply.
The following day we drove to the west park, which we toured 15 years ago. We stopped off at the Red Hills Visitor Center first, then continued along the scenic 5-mile Bajada Loop Drive along the Tuscon Mountain District foothills. These are some of the more memorable photos:
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| saguaro forest, a very different type of forest than what usually comes to mind |
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| these must be really old saguaros with so many limbs |
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| ocotillo in bloom |
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| it's not that Michael is short ... |
The saguaro flowers for the first time at approximately 65 years of age. The pretty white flowers appear in May and June, near the tops of the stems and arms. The blooms last less than 24 hours, open at night and remain open the next day. Bats pollinate the flowers at night while bees and birds, like the white-winged dove, pollinate them during the day.
Once the flowers are pollinated they mature into bright red fruit that ripens by July and is a source of nourishment for many birds and animals like coyote, javelina, and tortoise. Each fruit contains up to 2,000 small black seeds, which are spread by the birds and animals that have eaten the fruit. The seeds then take root, and if conditions are good, they eventually grow into mature cacti.
The Tohono O'odham have strong cultural ties to the saguaro. The first saguaro fruit harvest coincides with the Tohono O'odham New Year, when the summer monsoon rains fall on the parched desert floor. The O'odham use woody ribs of dead saguaros to create a tool, called a ku-pit, to reach the fruit clustered at the tops of the arms and crowns of the cacti.
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| the ribs of a dead saguaro |
At the Valley View Overlook, we walked the trail that climbed a ridge to a superb view of the Avra Valley below and Picacho Peak to the north.
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| Avra Valley and Picacho Peak, the same Picacho Peak where we watched the civil war reenactment |
On Signal Hill we viewed prehistoric rock art created by the prehistoric Hohokam people. These petroglyphs are more than a thousand years old, a legacy left in several areas of the desert by the ancient people living and passing through.
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| the petroglyphs |
In keeping with the cactus theme, tomorrow we will be off to Organ Pipe Cactus National Monument.