Creating a Healthier, More Livable and Prosperous Phoenix

Phoenix is poised to become the next great American City. The Tree and Shade Master Plan presents Phoenix’s leaders and residents a roadmap to creating a 21st Century desert city. The urban forest is a keystone to creating a sustainable city because it solves many problems with one single solution. By investing in trees and the urban forest, the city can reduce its carbon footprint, decrease energy costs, reduce storm water runoff, increase biodiversity, address the urban heat island effect, clean the air, and increase property values. In addition, trees can help to create walkable streets and vibrant pedestrian places. More trees will not solve all the problems, but it is known that for every dollar invested in the urban forest results in an impressive return of $2.23 in benefits.

Phoenix has a strong foundation on which to build the future. Phoenix residents value natural resources and have voted repeatedly to invest in the living infrastructure. For instance, the Phoenix Parks and Preserve Initiative was passed twice with over 75 percent voter approval. This modest sales tax has purchased land for the Sonoran Preserve, funded habitat restoration efforts along Rio Salado, built new parks and planted hundreds of new trees. These projects and others like it provide the base for a healthy urban forest. Trees and engineered shade have the potential to be one of the city’s greatest assets and the Tree and Shade Master Plan provides the framework for creating a healthier, more livable and prosperous Phoenix.

The Urban Forest – Trees for People

The urban forest is a critical component of the living infrastructure. It benefits and attracts residents and tourists alike to live, work, shop and play in the city. Phoenix’s urban forest is a diverse ecosystem of soils, vegetation, trees, associated organisms, air, water, wildlife and people. The urban forest is found not only in parks, mountain preserves and native desert areas, but also in neighborhoods, commercial corridors, industrial parks and along streets. The urban forest is made up of a rich mosaic of private and public property that surrounds the city and provides many environmental, economic, and social benefits.

In order for the urban forest to be a profitable investment, Phoenix must do more than just plant trees. The entire lifecycle of the tree must be addressed because the current planting, maintenance, and irrigation practices are preventing many trees from providing their maximum return on investment. The Tree and Shade Master Plan provides a detailed roadmap to address these issues, as well as many others, with realistic and incremental steps. To succeed, this plan requires a long-term investment from the residents and leaders of Phoenix.

Trees are Solution Multipliers

Solution multipliers solve numerous problems simultaneously. Trees are a perfect example of a solution multiplier because when planted and maintained correctly, they can provide many economic, environmental, and social benefits. According to the US Forest Service, trees benefit the community by: providing a cooling effect that reduces energy costs; improving air quality; strengthening quality of place and the local economy; reducing storm water runoff; improving social connections; promoting smart growth and compact development; and creating walkable communities (US Forest Service and Urban & Community Forestry). Trees are high-yield assets; for example, the City of Chicago values its trees at $2.3 billion dollars. Trees have a documented return on investment (ROI) in Arizona of $2.23 for every $1 invested (US Department of Agriculture Forest Service). This demonstrates the important role that trees have within the city's economy. This is why it is critical to manage and invest in the urban forest; the health of the urban forest is closely linked to the economic health of the city.

Maintainable Infrastructure

Phoenix is a desert city that has a history of several decades of drought. In order to achieve a healthy urban forest we must use water wisely. Currently, 60 percent of Phoenix’s water is used outdoors, mainly for landscape irrigation. According to the City of Phoenix’s Water Services Department, Phoenix has an adequate sustainable water supply to meet the State of Arizona’s 100-year assured water supply standard. This includes growth in Phoenix’s system water demand over the next 20 years or more. Nonetheless, to achieve a maintainable urban forest, water must be used more efficiently. This is done with high-efficiency irrigation systems, use of drought-tolerant plant material, strategic placement of shade corridors and continued education. In order for a healthy urban forest to exist, it must be coupled with strong water management.

Implementation

The Urban Forest Infrastructure Team and the Parks and Recreation Department are charged with coordinating and maintaining the Tree and Shade Master Plan. Many City departments will implement the plan as they work to fulfill their own missions. The Tree and Shade Master Plan will not only provide a framework to achieve an average 25 percent tree canopy coverage by 2030 but will also help to achieve many goals and policies from the Green Phoenix Initiative and the voter ratified General Plan.

The plan proposes incremental steps to achieve the 2030 vision and canopy goal. The City of Phoenix is beginning to put a process in place to preserve, maintain, and redevelop the urban forest. This plan intends to increase the quality of life and economic vitality of the city by recommending ways to create a sustainable urban forest for future generations.

Ozone is a highly reactive compound that is harmful at very low concentrations as compared to other pollutants. One method of pollution control is the use of photocatalysis, specifically with titanium dioxide to induce ozone decomposition. An experiment was designed and executed in order to determine the rate of decomposition by coating concrete in 5% by weight titanium dioxide mixed with paint. The experiment was unsuccessful in inducing decomposition but gave important insight into the adsorptive properties of ozone over surfaces, particularly with bare concrete that had an adsorption of 22.51 ± 2.457 ppbv, which was much better than the coated samples. Further studies into the development of photocatalytic paint is needed in order to develop an effective urban ozone pollution control method to be implemented in major cities, particularly in the most polluted such as Los Angeles, California.

In the early 2000s, Richard S. Legro, Mark V. Sauer, Gilbert L. Mottla, Kevin S. Richter, William C. Dodson, and Duanping Liao studied the relationship between air pollution and reproductive complications. In the United States, Legro’s team tracked thousands of women undergoing in vitro fertilization, or IVF, along with the air quality of both the IVF clinics and patients’ home locations. IVF is a reproductive technology during which a physician obtains mature eggs from a patient’s ovaries and fertilizes them with sperm in a lab setting outside of the body, after which the physician transfers the fertilized eggs into the patient’s uterus. As stated in Legro’s publication, Legro suspected that poor air quality would adversely affect live birth rates during IVF, so he compiled and analyzed the various types of pollutants that IVF patients were naturally exposed to in their homes and clinics. Legro’s experiment led to an increased awareness among patients about the dangers of conceiving via IVF in highly polluted areas.

In 1999, researcher Radim Srám, sometimes spelled Radim Šrám, published his article “Impact of Air Pollution on Reproductive Health” in the journal Environmental Health Perspectives. In the article, Srám analyzes the effects of exposure to air pollution, which can include harmful chemicals, on fetal growth and development. Srám discusses how industrialized countries such as the US and China have led to an increase in the global amount of respirable air pollutants. He mentions the influence that air pollution may have on the development of several birth defects, as well as the death of fetuses in the womb and infants after birth. Throughout his article, Srám summarizes the findings of several studies, and he describes the harmful developmental effects of common air pollutants, which has prompted further research in developed and developing countries into how air pollutants can cause birth defects and other diseases.

Many would contend that the United States healthcare system should be moving towards a state of health equity. Here, every individual is not disadvantaged from achieving their true health potential. However, a variety of barriers currently exist that restrict individuals across the country from attaining equitable health outcomes; one of these is the social determinants of health (SDOH). The SDOH are non-medical factors that influence the health outcomes of an individual such as air pollution, food insecurity, and transportation accessibility. Each of these factors can influence the critical illnesses and health outcomes of individuals and, in turn, diminish the level of health equity in affected areas. Further, the SDOH have a strong correlation with lower levels of health outcomes such as life expectancy, physical health, and mental health. Despite having influenced the United States health care system for decades, the industry has only begun to address its influences within the past few years. Through exploration between the associations of the SDOH and health outcomes, programming and policy-making can begin to address the barrier to health equity that the SDOH create.