I am drawn to wild places, like a moth to a flame. Like so many, my heart beats for the beautiful landscapes of my home in Oregon. The mountains call out to me; the forests whisper their welcome; the rivers run deep in my heart. I have spent a lot of time hiking in the Pacific Northwest, sweating it out on the trails.
While I love the lushness of the Pacific Northwest, I am also drawn to alien landscapes. Visiting places that are new to me awakens my mind and body to new sensations and curiosities.
A Foreign Land
The Sonoran desert of Southern Arizona is about as foreign to western Oregon as it gets. So, for a couple of weeks in March, I traded my muddy forest trails filled with towering conifers for the dusty desert of the Southwest in hopes of discovering a new place to love.
The sun hung low in the sky, when I met up with environmental scientist and Parsons Field Institute Coordinator, Mary Fastiggi and her colleague, Director of Development and Marketing, Adele Dietrich, for a hike in the McDowell Sonoran Preserve in Scottsdale, AZ. Our plan was to hike a small three-mile loop starting on the turpentine trail, and along the way, for Mary to show Adele and me a bit of the scientific work the Conservancy was invested in.
The Hike
- Trailhead: Granite Mountain Trailhead, McDowell Sonoran Preserve, Scottsdale, AZ
- Distance: 3 miles+
- Elevation Gain: 200 to 400 feet
- Details: There is ample parking at the trailhead and restroom facilities at the trailhead, but no water available. Educational signs and placards are available to read and learn more about the preserve. The preserve is open from sunrise to sunset. Automatic gates close off the preserve at this time.
Orientation
Before we set off, Mary oriented me to the Conservancy as a whole. “We are a stewardship organization that works in the Preserve,” explained Mary; the land itself is owned by the City of Scottsdale.
Started by local citizens, passionate about the land and concerned about land development; over the last 30 years, the McDowell Sonoran Conservancy has advocated for the care of the preserve, with the City of Scottsdale now owning roughly 30,500 acres of land in the Sonoran desert. That is ⅓ of the land area of the City of Scottsdale, and the equivalent of about 36 Central Parks.
Though the original focus of the McDowell Sonoran Conservancy was land preservation, its mission has “shifted from advocating for land preservation and then expanded to education and science.” Here is where Mary’s work really comes in. She is part of the science pillar of Stewardship at the Conservancy, with a goal of conducting ecological research in order to inform and inspire a deeper understanding of the Sonoran desert.
Urbanization
And there is a lot to be learned! One of the biggest threats to the Preserve and also a priority of the Parsons Field Institute, where the Science pillar is housed, are the impacts of urban stressors. The Phoenix area is the second-fastest-growing area in the U.S. so this is a major focus for the Institute.
Mary pointed to a map of the preserve found at the trailhead: “This is the Preserve in green,” she said. Though there was a lot of green on the map, you could also see that there was also a lot of land that was not protected, and thus open for development.
Connectivity
“Wildlife corridors are really really important for wildlife,” remarked Mary. With the Preserve adjacent to the Tonto National Forest and other protected land, the function of the Preserve for creating connectivity is paramount. “We want to make sure that connectivity stays connected,” expressed Mary.
With that in mind, there has been ongoing research on the use of the Preserve as a wildlife corridor and the impacts of nearby urbanization on wildlife. One break in the connectivity that is a concern is a road, Rio Verde Drive, that cuts across the Preserve.”
“We have done a Mule Deer telemetry study,” said Mary, to see how the road impacted migration. The study revealed different patterns of behavior between the sexes of the deer when it came to crossing the road, confirming that the road does pose a challenge.
However, one of the projects Mary was most excited about was a new Sonoran Desert Tortoise study, funded by the Arizona Game and Fish Department’s Heritage Grant. Mary directed my attention out past the map toward an open expanse of land. “It all looks like a desert,” she said, “but all this land can be developed and will be.”
The plan is to use telemetry to track the tortoises over time. By following the movement of tortoises, the Conservancy hopes to gain a better understanding of the impact of urbanization and other pressures on desert life.
Native Plants
After my orientation, Mary, Adele, and I all decided to head out on the trail. Enthusiasm was high as we began our walk along a dusty desert trail heading west.
However, we hadn’t made it more than a few yards when a colorful red color caught our eyes. According to Mary, it was a Hummingbird or Chuparosa plant! The Chuparosa is a beauty! Not just to me, but to hummingbirds, as well, who are attracted to the vibrant red blossoms of the plant. It is also “promoted for yards,” said Mary.
Surrounding the Chuparosa was a lot of golden-colored dry grass. “Red Brome,” stated Mary, “does pretty well and is naturalized across the Preserve.” This non-native grass was one of many we saw through the Preserve during our hike.
Tens of feet beyond the Chuparosa and grasses stood a shrubby plant. Mary grabbed a few leaves and held them to her nose and inhaled deeply. Invited to do the same, a sweet earthy, smell filled my senses. It was a Creosote bush. Apparently, the smell emanates from a waxy coating that protects the leaves from losing moisture during drought.
Interestingly, after a rainfall, the desert takes on the “fresh smell” of creosote, explained Mary. A reality I can corroborate, as the next week, following a rainy night, I went backpacking in the Superstition Wilderness and was enraptured by the earthy scent of what I could only assume was the creosote. It smelt like a fresh start.
Different Communities
We also saw some Yucca. Though not in bloom during our hike, in the spring, the Yucca grows clusters of flowers on stocks up to 6 feet high. These flowers are pollinated by the yucca moth which also depends on the yucca fruit seeds during their larval stage—an interesting mutualistic interaction.
We also saw the narrow-leaved turpentine bush. Though also not in flower, its leaves gave off a sweet smell, which is also an attractant for birds and insects that use the bush for food and shelter. Contrarily, it also attracts botanizing humans as well.
“You won’t find as much of these in the southern part of the Preserve,” Mary stated, referring to the Yucca.
“You don’t really see this one a lot lower either,” Mary pointed out, referring to the Turpentine bush.
Within the preserve elevation changes, as well as differences in rainfall and temperature, have resulted in many different community types or subtypes. “There is about a 700-foot difference in elevation from the lower parts of the Preserve,” explained Mary. Thus, depending on where you are in the Preserve, you will see a different mix of plants and animals.
Defining a Desert
So with all these differences, what exactly defines the Sonoran Desert? And why should I care?
At this point, we were nearing one of Mary’s Field Sites, but before I could focus my mind on what I was about to see, I just had to know—Why the Sonoran?
Mary stopped to answer my question: “The Sonoran desert is one of the most biodiverse deserts in the world,” said Mary. “It is also the only desert with saguaro cactus,” an indicator species, found consistently across the Sonoran desert.
“It is fascinating,” Mary went on, “it gets quite a bit of rain in some areas compared to other deserts.” It also has two rainy seasons—the winter rains and the monsoon rains. These rains bring about changes in the vegetation.
“Rainfall is very localized,” said Mary, contributing to habitat biodiversity, and ultimately, species diversity. Annually, you might get only 3 inches in one location and 20 inches in another.
Thus, though some things are consistent across the Sonoran Desert, like the Saguaro, it is the differences across its range that make the Sonoran Desert a spectacularly special place.
Desert Crust
Satisfied for the moment, Mary brought my attention to a checkerboard pattern of nail heads sticking up out of the soil. Behold—the soil crust experiment.
“Soil crust, which is a community of living things that are very very small and usually slow-growing, covers a lot of the Sonoran Desert,” Mary shared as we looked out on the microcosm. “In an untouched area you will find a lot of soil crust, but with human impact it is one of the first things eliminated.”
Despite the smallness of the community of microbes that create the soil crust, loss of soil crust is a huge deal in the Sonoran Desert! Not only is soil crust incredibly slow-growing (once it is gone it is gone), but soil crust retains water, aids in nutrient cycling, and stabilizes the desert soil.
“Have you heard of the Haboobs?” Mary asked. I hadn’t. “The haboobs are giant clouds of dust— a wall of dust—and they take over the city.” They literally “stop traffic” Adele offered. Why do these dust storms occur? Lack of soil crust.
So again, soil crust is small stuff, but kinda a big deal. As Mary puts it: “soil crust is the skin on the desert.”
Growing Soil Crust
In any event, the “nailhead” soil crust study is an attempt to better understand how soil crusts form. “To see if we can make soil crust faster,” said Mary.
Basically, the Conservancy, with the aid of volunteers, and in partnership with Northern Arizona University and the City of Scottsdale, collected soil crust from a city excavation site. Then took that material and treated it in a variety of ways. And now are watching to see how the microbiota of the soil crust will respond. Some examples of treatments include:1) seeded the soil crust with native seeds, 2) soil crust rolled out on burlap material with minimal disturbance, and 3) crushed and spread soil crust.
We got up as close as possible to see if we could see any developed soil crust but were unsuccessful. Normally the soil crust in the Sonoran Desert is thick and black with microbial growth. At this stage in the study, there was still not a lot to see.
Mary also mentioned that other scientists are trying to characterize the biota of soil crust in various deserts around the country. There is still a lot we don’t know about soil crust communities and how interchangeable, if at all, they are from region to region.
Restore a Desert
We continued on past the sparkling nail-heads of the soil crust experiment, tracing the path of power lines overhead. We even passed a pool of water along the trail, an unusual site to see in the desert.
Eventually, we made it to the next destination on our Preserve tour—the RestoreNet plots. This was the last major site Mary planned to show Adele and me. The RestoreNet site is an old camping and recreation area from before it was part of the Preserve. It was chosen from 67 sites identified via satellite imagery because it was impacted.
Mary explained the purpose of the experiment. “A lot of restoration projects are very localized. Most don’t go very well. There is a lot of seeding failure.” RestoreNet is an answer to this problem. By involving a “network of sites” across the country, the project hopes to provide land managers with more comprehensive information regarding restoration site treatments.
Treatments
“We are in charge of four RestoreNet sites in the Sonoran Desert,” said Mary. Each is different in terms of type and degree of impact, but each received the same treatments. At each site, “we have 36 different plots,” said Mary. Half are seeded with a warm mix and half a cool mix, with the exception of four untreated plots.
Mary took us around the site showing off the different treatment plots. There were mulched plots, plots with connectivity modifiers (basically metal stood up on end), seed-only plots, and pit plots.
Though it is still too early to tell what the RestoreNet results will ultimately suggest, there is preliminary data that is interesting. The first year of data gathered on the Colorado Plateau, for example, showed the use of pits did the best.
Though there wasn’t a lot of growth at the RestoreNet site we visited, we did see a few different lupine species in one plot, one of which is part of the cool species seed mix (Lupine sparsiflora or Coulter’s lupine). Mary said she would return in a week to conduct the spring plant monitoring, collecting data at all four sites.
Dry Winter
With an overall drier winter, the lack of plant emergence in the RestorNet site wasn’t necessarily surprising. The plots are not watered, so just like in a normal situation, the plants are relying on the weather for water.
Thus in addition to the plots, a rain gauge is set up on-site. The rain gauge was a simple plastic gauge holding an inch of water in the center with the ability to collect water beyond this capacity. Adele took a measurement that day and recorded it for the site: “0.57 inches.” “We have had rain here,” said Mary pointedly, so hopefully in a week, the plots will be in bloom.
Desert “Old Growth”
After visiting the RestoreNet site, Mary, Adele, and I took a right onto a trail heading toward Granite Mountain. The path was lined with cactuses, including Buckhorn Cholla and, of course, Saguaro.
I was especially enchanted by the Saguaro cactuses that stood proudly around us. There were so many of different sizes and shapes; many had several arms, the older Saguaro had cavities, and a few were in various states of decay. It reminded me a bit of the old-growth forests of Oregon and I asked Mary to talk more about the significance of Saguaro to the Sonoran Desert ecosystem.
Habitat
Saguaros provide excellent habitat for a variety of animals: from Gilded Flicker and Gila Woodpecker who build their homes in its flesh, to Owls and Martins who take advantage of empty cavities. Bats consume the pollen and nectar of the saguaro blossoms and many species eat the moisture-rich fruits of Saguaro in the summer months. A decaying saguaro reveals its internal woody skeleton; this becomes home for other desert species, including insects, snakes, and rodents.
When other sources become scarce, home animals rely on Saguaro for a freshwater source. The Saguaro’s pleated stems allow for expansion and contraction depending on the state of hydration. By feeding off the flesh of the Saguaro, animals like pack rats and mule deer take advantage of the Saguaro’s adaptation to drought.
Saguaro Life
The life of a Saguaro is long and requires certain conditions for success. According to Mary, Saguaros rely on nurse plants for successful germination. Without this protection, their chances of survival are slim.
The Saguaro also takes a long time to grow to their natural height of 35-40 feet over their up to 200-year life spans. Signs posted at the park state that “At age 40, a saguaro is only 3 feet tall.” Arms don’t appear until around 75 to 80 years according to Mary. It is no wonder that Saguaro is a protected species in Arizona.
Notice and Wonder
As we continued up the trail, Mary, Adele, and I continued to observe and identify the plants around us. I asked what else we might notice and wonder about in the Sonoran desert.
“This is the green time of year,” said Mary. “It can be greener, but it is greener than it has been.”
Adele pointed out the small size of the flowers and leaves in the desert. One key way to appreciate the Sonoran Desert is “taking time to see the variety in what others might go by,” Adele suggested. You have to stop and take notice.
So that is what we did.
We saw fairy dusters with their pink and red blooms; Palo Verde trees with their bright green stems and mistletoe growing in their branches. We saw baby Saguaro and old saguaro pods littering the desert floor; ocotillo with their stiff, spindly branches fanning up toward the sky; and many other unidentified blossoms on the desert floor.
Burning Questions
As we continued our way along, making our loopback toward the parking lot, the conversation shifted back to the priorities of Parsons Field Institute. It was at this point that we noticed several large plots of non-native grasses along the trail.
“Typically in a non-infested area, you would have a lot of space between plants,” explained Mary, but “invasive grasses take over those spaces.”
However, this is only the beginning of the problem. Besides outcompeting many other native plants, invasive grasses “turn brown and catch fire.”
“The Sonoran Desert ecosystem is “not adapted to burn at that intensity and it allows the fire to spread,” said Mary. She added: “The problem is that it is a positive feedback loop,” Essentially, this means that fires promote more fires, as plants adapted to fire like the non-native grasses return following a fire in full force, while others, like Saguaro, take a long time to recover. The result: many areas of the Sonoran desert are shifting toward grassland habitat.
This is “a massive threat to the Sonoran Desert,” Mary stated grimly. Managing the problem is a challenge as well. With a seed bank already established in the park, removal by volunteers is possible, but a constant battle.
Climate Change
Shifts in climate change is another area of focus for Parsons Field Institute, but it is hard to say what the long-term impacts of climate change will be. The main focus at the moment is monitoring in order to gather long-term data sets. With the help of over 500 volunteers, Parson’s has been able to monitor butterflies, bats, birds, arthropods, and plant phenology.
Stewards
The sun had sunk lower in the sky, and the large granite boulders that lined the trail were casting long shadows, as we neared the end of our hike.
However, before parting ways, I asked Mary and Adele to tell me more about volunteer opportunities at the conservancy.
According to Mary and Adele, people are involved in the Conservancy in many different ways. Some Stewards learn about the park through educational experiences. Other Stewards participate in research or volunteer restoration hours. Whatever their involvement, the goal is still the same—connection.
Sometimes the connection is deep. Adele told me of instances where people whose experience as a Steward has “shaped their retirement.” While Mary spoke of Stewards that were so deeply involved in science projects, that they consequently were listed as authors on publications.
A big part of the Steward program is “getting people to have a relationship with the land,” said Adele, and there are a lot of different ways that can happen.
No Place Like Home
After parting ways with Mary and Adele, I wandered the trails of the Preserve for a bit longer on my own—opening up my eyes, ears, and nose to the sights, sounds, and smells of the desert. I pondered the outstretched arms of the saguaro and marveled at the rounded rocks that lay jumbled across the landscape.
I spent several more days exploring the Sonoran Desert acquainting myself with its various moods and rhythms.
Adele had mentioned during our hike how my blog post was providing “an outsider perspective.” I can appreciate that.
But, at the same time, when I think about the bold desert sunsets and the moonlit nights, or of early morning bird song and the afternoon drying heat—I don’t feel like an outsider. I feel like I belong —in the wild Sonoran Desert.
Mary Fastiggi is the Parsons Field Institute Coordinator for the McDowell Sonoran Preserve. She has a B.A. in Environmental Studies and History from the University of Michigan and an M.S. from Arizona State University in Sustainability.
Adele Dietrich holds an MBA from Alaska Pacific University, is a Certified Fundraising Executive (CFRE) and holds the Chartered Advisor in Philanthropy (CAP) designation. Her goal is to connect individuals with their philanthropic passion.