Seattle leads the nation in sustainable urban forestry!

The Emerald City remains true to its name. The City of Seattle’s Parks and Recreation was awarded the distinction of Forest Stewardship Certification, the highest international certification for sustainable maintenance of forests. While FSC has become a standard for sustainability for timber forests, Seattle is the first metropolitan area in the country to receive this certification for urban forestry!

As the first Green City Partnership, Seattle represents the realization of a public-private model to bring the community together to promote healthy forests and sustainable ecosystems. We’re pleased to have been able to participate and share in Seattle’s success!

Currently, the Green Seattle Partnership estimates that 23 percent of the entire city is covered by tree canopy – but the goal is much greater: “We have a goal for our forest of 30 percent canopy for the entire city” says Mark Mead, senior urban forester for Seattle Parks and Recreation. Considering that the potential loss of urban forests in just 20 years without active stewardship is 70 percent, this 7 percent increase will take lots of work. But, we know Seattle is tackling this challenge in with the highest sustainability standards!

Congratulations Seattle!

How are you helping our city and region to expand the tree canopy …and all of the benefits that come with it?


New research estimates the value of Seattle’s urban forest!

Forterra has long recognized the importance of Seattle’s urban forests, parks and green spaces. They provide amazing access to nature for the city’s residents, help curb pollution, cool the city, absorb carbon dioxide, and much more. It was because we recognized the significance of these trees that we helped launch the Green Seattle Partnership in 2004 with the City of Seattle and other local nonprofit partners. But, until recently, much of that value was derived from research on non-urban forests or anecdotal understandings of the contributions trees provide.

Now, thanks to the publication of Seattle’s Forest Ecosystem Values: Analysis of the Structure, Function, and Economic Values, which documents the findings of a multi-year research effort by the Green Cities Research Alliance (GCRA), Seattle has hard science about the monetary value of their trees and the impact they have on carbon sequestration, energy, pollution and more.

Data in the report was compiled using the USDA Forest Service’s i-Tree Eco tool, the first use in Seattle. Given the Pacific Northwest’s unique climate, ecosystem and tree species, Seattle was previously not well served by similar urban forestry research from other parts of the country.

Some of the most exciting findings from the report include:

  • Seattle trees and shrubs are worth roughly $4.9 billion dollars (that’s what it would cost to replace them all)
  • They save the city around $23 million annually in carbon storage, pollution removal and residential energy savings, establishing Seattle’s urban forest as an irreplaceable capital asset
  • There are an estimated 4.35 million trees and tree-like shrubs in Seattle, which equates to a density of nearly 80 trees per acre
  • The three most common species measured were red alder, big leaf maple, and beaked hazelnut, all of which are native to this region.

This research is based on field data collection from 2011 and 2012 in 223 1/10-acre research plots distributed on both public and private property throughout the City of Seattle. Crews recorded size and species information for trees and tree-like shrubs, as well as land use and ground cover information.

The Green Cities Research Alliance is comprised of people from Forterra, USDA Forest Service, University of Washington, King County, and the City of Seattle, all of whom contributed to the research. GCRA was initiated by the USDA Forest Service Pacific Northwest Research Station in 2009 to build a program of research about urban ecosystems in the Puget Sound region. GCRA pairs scientists with practitioners and local decision makers to co-design and implement research efforts that provide relevant and practical information.

Download a copy of the 26-page report to read about all of GCRA’s fascinating findings, our research methodology and more!

The Art of Tree Management

“We managed light, we paint with light, and we paint with shade in our trees.”

A couple walks through the light and shadows created by an urban forest. Photo credit to Natalie Cheel

This is how Dr. Kim Coder begins his recent discussion of tree management on Arbor Views, the podcast for the International Society of Arboriculture.

What a unique way to describe how arborists integrate trees into our environment! They work with the absence and presence of light yet, their art sets its course in a potential stage, and arborists must continue to negotiate with the trees themselves in order to manipulate their benefits and obstacles.

“All the benefits we derive from trees, many of those things actually are a proxy for how healthy the crown is, how healthy the green stuff is. We can make bigger stronger trees …which is what arbor care is all about”

Several simple models help us develop each tree’s potential growth. This gives us better clues to evaluate how our own trees are doing. In fact, 78-82% of the weight mass of a tree is from water:

“If you look at a tree, if we had infrared vision, we could see that in a nice sunny day, it’s a fountain of water … below the leaves, coming from that crown is just a bubbling cauldron of water vapor.”

That description illustrates how Dr. Coder found that about 80% of all variation in tree development is due to water – whether there’s too much or too little or how the aeration process for the water vapor is managed.

This type of research demonstrates the greatest tool we have to manipulate the soil or the branches, and guide the tree as our paintbrush. But also, this research teaches us that more patience is necessary for letting the tree figure out its issues.

Who knew tree scientists are artists painting the canvas of our cities with light!

What do all these great streets have in common?

The website Better! Cities and Towns recently posted an article about what makes great city streets great. There are a lot of things at play in the examples they give from cities around the world, including multi-modal transportation, safe sidewalks, restaurants, and trees. I couldn’t help but notice that this was a common thread throughout all of the examples, and I was excited to see a portion of the article dedicated to the value of trees in urban areas and the effect they have on making city streets great. There was even a specific reference to green infrastructure benefits.

Here’s to green streets!