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FREE Regional Tree & Shade Summit in Downtown Phoenix on Wednesday

Growing Connections: Roots to Branches

Arizona and its communities face challenging problems with diminishing resources. How do communities do more with less? Green Infrastructure is a solution multiplier that provides cost effective solutions to many economic, social and environmental problems. All Arizona communities and businesses have a role in cultivating a healthier, more livable and prosperous future.

Presentations and a Discussion on Cultivating Green Infrastructure

The Regional Tree & Shade Summit will bring together municipal and private sector professionals for a one-day meeting to address the growing importance of regional tree and shade plans and green infrastructure to the long-term sustainability and success of our communities.



Wednesday, March 9, 2011
8:30am – 5:00pm


A.E. England Building @ Civic Space Park
424 N. Central Ave, Downtown Phoenix

Adjacent to Downtown Phoenix Central Station. Light Rail Use Strongly Encouraged


Space is Limited: Register at

More information

If you have any questions, please contact Anne Reichman at or call 480-965-2168.


This event is brought to you by: 

  • Arizona Forestry
  • ASU Global Institute of Sustainability
  • City of Glendale
  • City of Phoenix
  • City of Mesa
  • US Department of Agriculture Forestry Service

The Centennial Way project and the issues of shade in downtown Phoenix

The DVC will be dealing with issues of the City of Phoenix‘s proposed “Washington Street Centennial Way Project and Shade Aspect Recommendations” at tomorrow’s meeting. Local architect Taz Loomans’ column blow is directly related to this initiative.  In it, she makes the case for NATURAL shade in the urban core.

[Source: Blooming Rock]

A great example of engineered shade used in conjunction with trees at the Civic Space Park. Shade structure designed by Architekton. Photo from Arch Daily.

As I’ve discussed in the previous weeks on the Wednesday Phoenix Tree and Shade Masterplan series, the first step outlined in the Masterplan to restore our urban forest is Raising Awareness.  The second is Preserve, Protect and Increase.  Today I’ll be talking about the third and final step towards the Masterplan’s 2030 goal of a 25% canopy coverage in Phoenix – Sustainable, Maintainable Infrastructure.

The goal of this step, according to the Masterplan, is to “Treat the urban forest as infrastructure to ensure that trees and engineered shade are an integral part of the city’s planning and development process”.  When I think of infrastructure, I think of roads, storm water drains, and power lines, but I’ve never thought of trees and engineered shade as infrastructure.  But the definition of infrastructure, according to Wikipedia is:

Infrastructure is the basic physical and organizational structure needed for the operation of a society or the services and facilities necessary for an economy to function.

As I discussed in a previous post, a healthy urban forest is essential to the well-being of our city.  It is, indeed, essential for our society and economy.  And therefore, it’s not a leap to consider our urban forest and engineered shade as part of our city’s infrastructure.

Today is the first day I’m mentioning engineered shade in this Wednesday series on the urban forest.  Engineered shade is basically a man-made shade structure.  When it is not possible to put shade trees in an area, engineered shade becomes a good option.  Engineered shade can be attractive, artistic, and of course, it helps shade the city which adds comfort to being outdoors and also mitigates the heat island effect.  It can also act as a substructure for solar panels.  Certainly engineered shade is a solution multiplier.

However, I think it is important to note that engineered shade does not solve as many problems as trees do.  In fact, it is a poor substitute to nature’s solution to shade, improving the air quality, and reducing storm water runoff.  So whenever possible, it is best to plant a shade tree instead of building engineered shade, which does consume energy and resources in its manufacturing, whereas trees immediately contribute to the environment without ever asking for much in return.  Don’t get me wrong, engineered shade on and around buildings is appropriate whereas trees are not, and in that case, it is beneficial and necessary.

This brings me to the point of why people would opt for engineered shade, a more expensive up-front cost, over planting shade trees in open areas.  The first and foremost reason is that they might be afraid that they can’t maintain those trees over time.  That perhaps trees do ask too much in return.  This is where the final recommendation of Sustainable, Maintainable Infrastructure comes in.

Here are the challenges cited in the Masterplan with the current system in terms of maintenance:

  1. Currently, regulations in the City Code and Zoning Ordinance pertaining to vegetation maintenance in city right-of-way are difficult to enforce, and do not have any tree protection/preservation requirements following Certification of Occupancy.
  2. The city has generic tree inventory and salvage standards that are unclear and difficult to implement.
  3. There is a lack of consistent maintenance standards, as well as new tree planting specifications. Several valuable mature trees are lost each year due to improper planting and maintenance.

Some solutions to the maintenance challenge are:

  1. Tree Permitting – this would insure the tree is planted correctly in the first place, insuring its survival
  2. Planting and Irrigation Standards
  3. Landscape standards based on concepts of Right Tree, Right Place

Another reason one might opt for engineered shade over planting a shade tree is that a shade tree will consume too much water, a precious resource in the desert.

Some solutions to the water challenge are:

  1. high-efficiency irrigation systems
  2. use of drought-tolerant plant material
  3. strategic placement of shade corridors
  4. continued education

Remember that there are 30 to 40 trees available to us that are appropriate to our climate that would not consume an inordinate amount of water.  So let’s not use water consumption by trees as an excuse to deplete our urban forest.

Understandably the City might be shy about adding trees to their load at the moment, considering their slashed budgets.  They may be tempted to suggested engineered shade over shade trees for fear that they can’t maintain them.  But the City must first and foremost lead by example.  If the City expects private property owners to take care of their trees and plant new ones, the City itself must do so first, especially on showcase projects like Centennial Way, a State-funded project involving improvements on Washington Street between Central and and the State Capitol.  Installing engineered shade in lieu of shade trees, as suggested by some in the City, would be a very short-sighted, knee-jerk reaction to solving a problem that needs level-headed creative thinking.  Shade trees on Washington will become a long-term legacy to the City of Phoenix in a way that engineered shade alone will not.

As I mentioned in last Wednesday’s post, we can establish something like a Tree Fund or  tap into other community-based resources to help plant and maintain new shade trees along Washington and we will be giving a tremendous gift to future generations of Phoenicians.  Engineered shade should be used in conjunction with shade trees, not instead of them, as there is a need and a place for both types of solutions on the project.  Let’s not be blinded by the urgency of balancing the current Parks and Recreation budget and make rash decisions that will effect generations to come.

Note:  Don’t forget, there is a Tree Planting event this coming Saturday morning (the 11th)!  Click here for more details.

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Tree Planting at Steele Indian School Park

[Source: HandsOn Greater Phoenix]

Photo credite: Daniel Greene on Flickr

Calling all green thumbs and tree-huggers! Join us for a morning of environmental action as we plant trees and revitalize one of Phoenix’s best-known parks. Please wear clothing you don’t mind getting dirty and closed-toed shoes. Remember to bring a water bottle and sunscreen!

The minimum age for this project is 8 with an accompanying adult. Volunteers ages 16 and 17 who wish to participate without an accompanying adult must bring a signed Youth Volunteer Waiver. Please download the waiver from the “Youth Volunteer” link on the website’s menu.

By signing up for projects and not attending, you may be depriving someone else of the opportunity to participate and the project of much-needed support.

Please note that in an effort to accommodate volunteers who sign up for projects by choice, HandsOn does not accept court ordered volunteers and will not sign off on any court-related documents.

You must register to participate.


Saturday, September 11, 2010
7:00AM – 10:00AM
Location: Phoenix, AZ 85015
The full project address and directions will be sent to you by e-mail after you sign up.
Accommodations for volunteers with disabilities:You will have the opportunity to request accommodations after you sign up for this project.

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ASU researcher outlines strategies to curb urban heat island (downtown Phoenix cited)

[Source: EurekaAlert] — Protect yourself from the summer sun is good advice to children who want to play outside on a hot summer day and it is good advice to cities as a way to mitigate the phenomenon known as urban heat island.  For children, a hat, long sleeves and sun block provide protection.  For cities, it might be canopies, additives to construction materials and smarter use of landscaping that helps protect it from the sun, said Harvey Bryan, an ASU professor of architecture.  Bryan presented several possible strategies a city could use to help it fight urban heat island (UHI) in a presentation he made at the annual meeting of the American Association for the Advancement of Science, held in San Diego, Feb. 18 – 22.  Bryan’s presentation, “Digital Simulations and Zoning Codes: To Mitigate Urban Heat Island,” was presented on Feb. 21 in a session on Urban Design and Energy Demand: Transforming Cities for an Eco-Energy Future.

Urban heat island is a phenomenon experienced by large cities, especially those located in desert areas, where the constant heat of the day is absorbed by the buildings, pavement and concrete.  The result is a rise in nighttime low temperature for a city’s core from the stored heat of the day.  The higher nighttime temperatures mean more cooling is required for residents’ comfort, resulting in increased power demand and potentially more greenhouse gases emitted.  Phoenix, where summer nighttime temperatures often do not go below 90 F, is a classic example of the UHI, Bryan said.

Citing work he participated in about a year ago – with Daniel Hoffman, an ASU professor of architecture and Akram Rosheidat, an ASU doctoral student – which focused on ways of improving pedestrian comfort in downtown Phoenix, Bryan outlined several methods a city can employ that will help alleviate the UHI.  Shade, not surprisingly, is one of the prime tools.  “Canopies to shade streets and sidewalks keep the concrete and asphalt cooler,” Bryan explained.  “Interestingly, sidewalks in downtown Phoenix during the early 1900s were canopied.”

Bryan said another key aspect is being smart on material choices for the canopies.  “In addition to shading devices, color and thermal properties are also important considerations,” Bryan said.  “Lighter colors are best for any surface in the Valley. You also have to consider the heat capacity of the materials – denser material will absorb heat during the day and are slow at re-emitting at night.”

In areas that cannot be canopied, Bryan said material additives use could play an important role.  Phoenix, for example, has a large number of parking lots and streets that constantly absorb daytime heat. “Introducing additives, like crumb rubber to asphalt and concrete, are ways of reducing heat capacity at the surface and making for a better nighttime profile,” he said.  “The important part is to look at materials performance more than just during the daytime.  We need a 24-hour profile to see how materials absorb heat during the day and how they emit it during the evening.  We then look for materials that are reflective during the day and highly emitting during the evening.”

All of this points to modeling as an important tool in mitigating UHI.   “It comes down to how we model the downtown and how we look at various scenarios with different materials using models that accurately simulate the radiative phenomena,” Bryan explained.  “Most cities have never used such powerful tools to find solutions to UHI.”

Opinions vary on shade capabilities of Phoenix light rail stations

[Source: Ron Sanzone, Arizona Republic] — Valley Metro light rail is incorporating three elements into a shading system it hopes will keep light-rail passengers comfortable at its stations as they await trains.  But public opinion differs about the shading system.  Two individuals involved in downtown planning efforts provide their perspectives:

Mike James, architect involved in Metro’s station planning

Dan Hoffman, professor of architecture at Arizona State University

The three-layered shading system was the best of five designs presented by teams of architects to Metro, in part because it blocks reflective heat that comes off the asphalt on nearby streets.  Here’s how each system element works:


  • Canopies.  A series of angled overhead canopies made of tensile material will shade the waiting areas of station platforms throughout much of the day. Unlike most other materials, the temperature of the tensile fabric will not heat up beyond the surrounding air temperature, a key to keeping the areas underneath it cooler.  Aesthetically designed to resemble birds in flight, the canopies are “a signature look that is unique to Phoenix.”
  • Vertical shades.  Also referred to as louvers, these shades fill in the coverage gaps left by the canopies during early-morning and late-afternoon hours.  Slanted downward and upward at 30-degree angles, the shades have the appearance of open sets of blinds.  Metro decided against a solid opaque design because local businesses wanted to be fully visible from stations and neighbors wanted to be able to keep an eye on station platforms for security reasons.
  • Green screens.  Located at most stations, these trellises are vertical metal cages that will be covered with vines.  They will provide the station with additional shade and a small amount of moisture produced by plants.

 To provide additional relief, each station will feature a drinking fountain, a canopy of three to six trees, and paint that does not heat up covering the metal areas that might be touched by passengers.

Q: What do you think of the shading design Metro is using for its stations?  How effective will it be?

A: It’s not optimum, but it does perform at a basic level.  The canopies are made of white cloth, which is good because they reflect a lot of the heat, though the edge of cloth is up high and would provide more shade if it were lower.  Their solution was not optimal but was sufficient.

Q: Are there any problems you see or concerns you have with the design of the stations?

A: There are aspects that are good, such as the shade cloth.  I like the dynamic utilities.  I don’t think it’s the most efficient design possible.  It does provide the basics, but doesn’t provide the highest quality design-wise.  What was chosen was good, not great, and sufficient, not optimal.

Q: What could have been improved?

A: The actual steel structure, which is expensive, could have been done in a more elegant and simple way.  It’s flamboyant.  Moisture and plantings would improve it and cool it down more, but that would have required more money.

Can landscaping make Phoenix “walkable?”

[Source: Richard Nilsen, Arizona Republic] — The skyline may be interesting, but it is not where we live.  “We should not care about the skyline but the streetscape,” says Nancy Levinson, head of the Phoenix Urban Research Lab at Arizona State University.  “The skyline of Manhattan is something you appreciate in New Jersey.  In the thick of Manhattan, you’re excited about the streetscape. The skyline is something you see from a specific angle.  Many great cities don’t have a great skyline.”

And it is that street-level view that is lagging most in Phoenix.  “All good cities share a common quality,” Phoenix architect Eddie Jones says.  “They are walkable.”

Phoenix doesn’t make the grade.  “Downtown Phoenix is not a pleasant environment,” says Dean Brennan, a planner with the Urban Form Project, a city initiative to guide development. “People don’t come to downtown Phoenix to walk around — not like they do in downtown Tempe.  In Phoenix, we talk about shade.  That seems obvious.  But when a building is designed, you’d think shade would be a critical element of that design, but it’s not.  Shade isn’t provided.  Maybe some trees or a canopy, but it’s an afterthought.”

The question is: If the temperature is 105 degrees even in the shade, will landscaping be enough to turn Phoenix into a “walkable” city?  [Note: To read this article and online comments, click here.]

Internet mapping services work to lay out Phoenix walking routes

As noted in an Associated Press article reprinted in Sunday’s Arizona Republic, Internet mapping services are working to lay out the best biking and walking routes. 

For example, if you visit Google Maps, click on “Get Directions,” and type in a Start Address and End Address, up pops two alternatives: By Car and Walking.  Click on Walking and the “most direct” route (distance and time) will be shown.  It’s also noted that “Walking directions are in beta.  Use caution when walking in unfamiliar areas.” 

Okay, that’s a start.  Now if Google Mappers could only show where shade trees, awnings, and overhead misters are located in hot, hot, hot cities like Phoenix, that may adjust your route!