Mid-Summer Night’s Dream
Patterns of Life in an Urban Sea
At midnight the heat radiates from the cement driveway under my feet. I stand in the white moonlight gazing up at twinkling stars. The dark outline of tall trees and roof tops form a stage-drop where city glow breaks the blackness of night.
This is my summer ritual – star-gazing in my pajamas. I wake out of some consciousness that tells my snoozing brain I can open the doors and go out to a cool 85ْ F!
It’s summertime in Phoenix, Arizona. Temperatures soar over 100. Yesterday was a crisp 116ْ. After June, the heat island effect kicks into gear. Buildings and streets – especially asphalt surfaces – absorb the day’s solar energy, then release it slowly through the night. Even though the sun goes down, the built environment is still hot. The hum of air conditioners is a constant auditory feature of summertime.
Here in Tempe there is humidity from the old irrigation system still in use. Once a week residents open aqueduct valves in their yards to allow water to flow. Encircled by raised earth berms, the water is held so it slowly soaks deep into the ground. This is an old way of life to support large trees and grass lawns from a time when Tempe was a tiny agricultural town in the early 1900’s.
People moved to Tempe to enjoy the dry, mild climate, and to escape allergy causing vegetation. However, the Eastern trees and plants people brought with them (mulberry and olive, for example), and their love of grass, resulted in Phoenix becoming the asthma capital of the west.
Nearby Arizona State University is our land-grant university. My little house sits behind a friend’s large art studio. It is a plum of a house and only a short walk or bike to my workplace at the Center for Environmental Studies at A.S.U. In the hot afternoons I swim in the Olympic-sized pool at the University along with bronze co-eds and swim team athletes.
My house is surrounded by large trees and a grass lawn maintained beautifully by grounds keepers. Old Tempe is a remnant of an outdated way of life in the desert: just add water and cultivate an oasis. It was a way that made sense to residents and developers when water was plentiful, and when temperatures were cooler, and summers only four months long.
Over the last 50 years the average low temperature has increased by 10ْ F. The city’s growth is exponential now. The population since 1990 increased by 59%! This is unsustainable with available water, even though theoretically there is much more desert to develop across the expansive valley floor.
City mothers and fathers are currently examining critical decisions Phoenix needs to make to sustain a live-able future. How and what they decide to do to shape the city’s growth will be an important example for metropolitan communities across the West.
In 1998 Arizona State University was awarded a major grant from the National Science Foundation (NSF) for a Long Term Ecological Research Study (LTER) as one of two urban sites. Phoenix and Baltimore were chosen as two urban cities to be studied. We are a city growing by the process of sprawl, and Baltimore is an older city that has filled in its borders, and now grows inward and up.
NSF wants to know what is happening to the ecology of living communities in cities – since nearly 80% of the world’s population now lives in or near an urban area. The study seeks to answer questions that indicate the health of ecosystem functions in urban areas. How are native animals and plants coping? How quickly is organic matter turned-over (decomposed to soil, elements in the air, and water again)? What is happening to water and air quality?
The Central Arizona Phoenix Long Term Ecological Research Study (CAPTLER) began a twenty-year study of these factors along with human behavior patterns such as where we choose to live in the city or how we use water among many others. The study recognizes that landscape affects human activity as much as humans impact landscape. These forces work together to shape urban environments.
The Greater Phoenix 2100 study initiated by Arizona State University collects and disseminates data for possible scenarios of growth and quality of life to be used by policymakers. It looks at trends over time. For example, three projections are made for population by 2050: at current annual growth rates (4.4%), the lowest annual growth rate in the last 50 years (3.4%), and the lowest annual growth rate in the last 100 years. Projected population in 2050 based on these three rates could result in 28.2, 17.4, or 10 million people respectively. Citizens and policy-makers looking at these numbers can make decisions now that will help them shape tomorrow.
The Long-Term Ecological Research Study is reporting loss of indigenous biodiversity on mountains in Phoenix surrounded by an urban sea of human activity. These habitats are essentially like islands. Isolated species that can not relocate represent small populations with consequent small gene pools. Inbreeding weakens the biological fitness of species if prolonged. Scientists believe this is happening to many species of plants and animals in the urban perimeters of Phoenix.
One of the most harmful assaults to native species diversity is the introduction of non-native plants and animals. Successful non-natives have no natural predators in the new environment. Thus they can out-compete native species for habitat and resources. On species of tree – the Tamarisk – has reduced native trees along Arizona’s already vulnerable riparian green belts (areas where the water table is close to or above the ground). Riparian habitat has been reduced by 90% in Arizona over the last century due to human activity.
For thousands of years these riparian habitats supported the greatest species diversity in our state. Beavers and otters abound in rivers and streams, and mega fauna like deer found sustenance there. Today one has to visit a museum or zoo to know what native species Arizona once supported. Many residents in Arizona are unaware of what is a native versus a non-native due to the importing of exotic species. In other words the cultural memory of the original landscape is being lost with each generation.
In many ways what Phoenix does over the next decade to slow and manage growth, and to clean up and use water more responsibly will be rich learning opportunities for cities across the Southwest facing similar issues. A profound shift is happening in the West where growth is out of control and the Earth is showing strains of overuse and over-harvesting.
Tucson, Arizona where I now reside is 100 miles south of Phoenix and higher in elevation. We are called the Upland Desert. Tucson currently follows the Sonoran Desert Conservation Plan, a multi-agency and community-based initiative, to shape its growth. Although Tucson has its own sprawl (it has reached nearly one million people in the metro area), it is still known for its open space and residential landscaping with native desert corridors. Native Tucsonans are desperately trying to hold onto this legacy. But many new residents who do not understand desert ecosystems, or appreciate the way of life necessary to protect water reserves, build huge homes with lawns and pools. They represent a threat to a way of life that has existed here for tens of thousands of years.
Since I moved here from Phoenix six years ago, I can still enjoy a cool summer night at the decent hour of 7 pm when desert soils release the heat of the day. This is the natural desert rhythm that Phoenix has lost by asphalting over much of the valley floor.
On morning walks in central Tucson, I enjoy a covey of Gamble’s quail running wildly through the native vegetation in alleyways and yards. Many people pride themselves on landscaping with desert trees like the graceful desert willow with its lavender throated blossoms and uniquely shaped cacti placed as you would sculpture. They tend gardens where heirloom vegetables conserved from the Americas grow with little water. The Tohono O’Odham still dry farm using only annual monsoon rains to grow corn, beans, melons, and greens of all kinds.
Striking the balance between natural communities and human communities makes sense. We are in a new period of understanding the intimate and wholly necessary relationships with nature that maintain us physically and economically, emotionally and spiritually.
It is an exciting time for Arizona, one filled with great potential to rework our plan for human habitation. How do we balance quality of life with quality of environment? How do we develop a way of life that is in sync with the natural communities that make this land such a fabulous place to live and work?
Gazing at the twinkling night sky above me at midnight, I wonder if Hohokam people also lay outside in the cool of moonlight thousands of years ago. A soft breeze moves across the yard as I doze off in my chaise lounge, in another desert town, in my pajamas on a summer’s night under the heavens.