College life can involve experimentation, but usually not of the scientific variety. Now, though, some ASU students will begin living an experiment, one designed by scientists in the Environmental Studies department to investigate ecological effects of landscaping, and to find out what people in the Valley really want in their yards.
Take a walk around North Desert Village, the former Williams Air Force Base housing that is now part of the University's family housing within ASU East. Rental houses, like any others, greet you in blocks mini-neighborhoods. While the "inside" lives of the tenants of 24 of these homes will go on as usual, scientists will be homing in on exactly what they do "outside" - how they use or transform their very different experimental yards.
"This is a new idea, to do an experiment where people are living. We then include also human ecology, how they behave and think as part of the experiment. It is rare to try to integrate all of these things at once," said field project manager Diane Hope, Ph.D.
The study, designed by Central Arizona Project-Long Term Ecological Research Program scientists, will involve planting four different landscapes. Four mini-neighborhoods (six houses organized around a common area) within the 152-house subdivision will be landscaped according to these four outdoor themes:
- Xeriscape with a variety of desert plants
- Xeriscape with trees and shrubs native to Arizona
- Mixed theme with some lawn and some desert
- Mesic: Full green lawn with trees and shrubs
The themes, of course, represent typical landscaping found in Phoenix. The experiment will measure the effects of these landscapes, not only on birds and insects, yard temperature and water use, but also on the humans who live there.
"Nobody's looked at, say, environmental values, recycling behavior and social networks - all three. So, we're trying to put all three together," said David Casagrande, Ph.D., cultural anthropologist and co-author of the study.
According to Graff, "One of the concerns was from the families with children; that if it was going to be desert plants, that it not be the prickly kind." The project designers quickly decided to put in similar, non-spiny plants in their place, with only a few prickly plants in protective cages. Graff was pleased that the researchers were taking into account the people in the experiment.
To understand urban ecology, people must be included the experiment. What is different about this experiment is that these residents are allowed to do exactly what they would normally do. They may even install grass in a "desert" yard or set out pots of geraniums if they so choose, a process Hope called "adaptive experimentation."
The people involved in the experiment are meant to reflect a typical mix of Phoenix-area citizens. Though some may argue that students are "all alike," so far, according to Casagrande, the participants represent a mix of ages, ethnic backgrounds and family sizes.
Parked outside one house is a semi truck. In other driveways are family cars, and pick-up trucks with business logos, along with bicycles. Christmas décor abounds, as do soccer balls and tricycles.
But they have this in common: All have agreed to be part of a trailblazing, long-term experiment. They will be interviewed about their environmental values, natural knowledge, social networks and landscape preferences. As time passes, they will be surveyed again to see if their opinions or their knowledge have changed.
New student families will be interviewed when they move in, and consent to be part of the experiment. Agreeing to be part of the experiment will be required of all adult members of families who rent those 24 houses for as long as the experiment is in place. Right now, the houses are nearly all occupied, and according to Casagrande, there has not been a problem finding residents to be part of the study.
Walking her dog in North Desert Village where she lives, Lynn Graff, student housing director at ASU East, spoke as she pointed to a common area laid out with landscaping stakes.
"They chose an area here that is enclosed with houses surrounding it so they can control and study everything in that little area. This will be a good chance for them to study the different kinds of landscape plants that will work in this environment, including the people in it ...We're very pleased to see them doing some things that will enhance it, and give us feedback about what works well."
The experiment is meant to be realistic. After the initial landscape installation, participants will choose the houses that they will move into, subject to availability, just as they would in other rental houses. One young student and her husband said they would really accept any landscaping that was put in, because they liked the house and location, and really don't use their yard.
A resident family may also occasionally be reminded that they are variables in a grand experiment. A technician may bicycle by every hour on a particular day for example, counting the number of people planting flowers and children playing. The intrusions into the life of the families in the housing are meant to be minimal. Much data will be collected with automatic sensors to measure water use, temperature and other variables within the yard.
In preparation for the study, Casagrande and other researchers conducted surveys of residents already living in the housing. Thankfully, they discovered and prevented several potential problems. Gravel should be too small to throw and too big to look like kitty litter, Casagrande said.
The scientist "principal investigators" of the project intend to continue this experiment for as many years, and through as many tenants as possible. They have announced the beginning of the National Science Foundation-funded study in November's Frontiers in Ecology and the Environment, and a sociology journal, Human Organization.
Casagrande stressed the importance of putting peoples' perceptions of landscaping to the test, along with the biological data that will be collected.
"What we're studying in this experiment, specifically, is that you go in, you put in a desert landscape here and you put in a grass landscape there, and you watch what happens. Do people get to like the desert landscape? Or do they continue to hate it, but accept it anyway? Why? Was it their environmental values? Was it their social networks? What was it that made them accept or not accept this imposition of a new landscape? This is very important for policy," Casagrande said.
Investigating peoples' perceptions of low-water-use landscaping is arguably critical to the future of a desert city. According to one estimate, a fourth of the drinking water for the city of Phoenix is used for landscape irrigation. Many policy makers already recognize the problem of an exploding population and a finite supply of water. They say that the way Phoenix will safely grow is by consistently and steadily reducing the per capita water use.
In Casagrande's interviews, desert landscaping was the most-mentioned idea for the community to reduce water use. Right now in Phoenix, it is a phenomenon cultivated by landscape architects.
Janet Rademacher, landscape architect liason at Mountain States Wholesale Nursery reports that about 90 percent of the projects that she assists with involve solely desert landscaping plants. "It has really become the norm as opposed to a specialty landscape... Landscape architects have been really open and progressive in using desert plants."
She said that since customers choose plants that look good, water-saving or not, she emphasizes the attractiveness and variety of these plants. "Rather than focus on water conservation, we show people the beauty of these plants," Rademacher said. "People want to do right thing and save water, but we want to use plants that give us a sense of place, so you know you're in the desert and not in New York or San Diego."
The North Desert Village Experiment researchers hope to answer questions like these:
- Do people with a full lawn actually use it more than people who have 15 square feet of grass?
- Do people who attend a certain church and share gardening tips tend to prefer certain landscapes?
- Do those born in Phoenix actually like the desert landscaping, or just want to spend less for water?
According to Casagrande, "Your perception of a landscape and the landscape you end up having in your yard is such a compromise of different needs in your life and different types of values that you have. It's really hard to predict. It's one thing to say, you just can't predict, and just throw up your hands and walk away. But it's another thing to hope to be able to say that if we're going to develop policy to conserve water, we need some better understanding than what we have now."
Sources
Dr. David Casagrande, Post-Doctoral Research Associate, Cultural Anthropology
Lynn Graff, Director of Student Housing, ASU East
Dr. Diane Hope, field project manager, CAP-LTER North Village Residential
Landscaping Experiment
Janet Rademacher, Landscape Architect Liason, Mountain States Wholesale Nursery
References
Frontiers in Ecology and the Environment, Nov. 2004 "Learning to Roll with the Punches: Adaptive Experimentation in Human-Dominated Ecosystems." Cooke et al.
