It’s common for Northwest residents to spend some time in the Southwest during the winter to get away from the rain. Ruth and I have, as a result, spent a couple of weeks each year in Arizona, Nevada, etc. We have used the opportunity to learn about deserts and now love them. If you had asked me about desert U.S.A. (excluding Alaska) before we moved to Washington, I could have told you what I knew about our 4 desert systems in about 10 minutes. That has changed. As 2014 began, Ruth and I were filling in gaps in our knowledge about the desert we least knew–Great Basin.
The Mojave, the smallest of the 4, is mostly in California but spills into southern Nevada. It ranges from 282 feet below sea level to almost 12,000 feet at the top of Mount Charleston, Las Vegas’ cool playground. But the general Mojave, which contains the U.S.’s lowest and hottest places, has an elevation range of, say, 2,000 to 5,000 feet. Each of our 4 deserts has what is called an indicator species, and the Mojave’s is the Joshua tree. Not actually trees, these yuccas can grow 40 feet tall and so are mistaken for trees. I love the drive up Mount Charleston because it passes through several ecosystems and one of them contains Joshuas that decorate the landscape like cheerleaders with pom pons. The Joshua is only one of the approximately 2,000 plant species in the Mojave including lots of the familiar prickly pear. This desert has become a center for alfalfa production. One of its more interesting residents is the pinacate beetle that gets all of its moisture from vegetation and never drinks water. The Mojave gets less than 13 inches of rain a year which hasn’t kept it from containing a huge city, Las Vegas. If you want to learn about the Mojave, I’d recommend separate visits to Joshua Tree and Death Valley National Parks…in the winter. They are very different experiences because Joshua Tree is upper desert and Death Valley is lower.
The 100,000 to 120,000 square mile (estimates vary) Sonoran Desert abuts the Mojave in both California and Arizona and stretches south several hundred miles into Mexico including a big chunk of Baja California. The Sonoran is more than twice the size of the Mojave and the lushest of the four deserts with about 2,000 plant species in the agave, palm, legume, and cactus families. The indicator species, at least for me, is saguaro cactus, but creosote bushes are bountiful in its valleys. Part of the reason for the Sonoran’s relative lushness is a 2 season rain pattern. From December to March Pacific Ocean storms sometimes make their way here. From July to September monsoons bring tropical air to the desert in the form of brief, usually violent thunderstorms. Fairly dependable moisture supports 60 mammals, 100 reptiles, 350 birds, etc. My favorite Sonoran birds are several species of hummingbirds best seen in Ramsey Canyon. My favorite mammal is the javelina, which looks rather cuddly but doesn’t have a cuddly disposition. The Sonoran’s megacity is Phoenix, which has a great botanical garden. But if you really want to understand The Sonoran, go to Tucson where there are at least 4 outstanding teachers–the 2 sections of Saguaro National Park on either side of the city, The Arizona-Sonora Museum, and the lesser known to outsiders Tohono Chul Park, my favorite.
The other 2 tomorrow.