Category Archives: Alien ornamentals

Portland: A New Kind of City II

In Portland: A New Kind of City I, I argued that if Portland is to achieve some of its other policies in the Watershed Health and Environment chapter of Working Draft 1, Portland Comprehensive Plan, policies such as Biodiversity and Habitat Corridors, it is important for any policy on Vegetation to stress the importance of NATIVE vegetation–in part, because native species of insects, the base of the food chain, need native plants to survive.

I want to now draw your attention to policies under the “Design With Nature” section of the Urban Design and Development chapter–one of the sections with the greatest potential to lead to transformational design and a new kind of city.

Policy 5.45 Greening the built environment. Encourage the incorporation and preservation of large healthy trees, native trees, and other vegetation in development. 5.45.a. Prioritize integrating natural elements and systems, including trees, green spaces, and vegetated stormwater management systems, into centers. 

Change Policy 5.45 and 5.45.a. to:  5.45 Encourage the preservation of existing large healthy trees and encourage the incorporation of native trees and other native vegetation into development.  5.45.a. Prioritize integrating natural elements and systems, including native trees, natural areas, and stormwater management systems utilizing native vegetation into centers.

Invasive English ivy and Himalayan blackberry growing along the Willamette River in February. Green is not always "green"!

Invasive English ivy and Himalayan blackberry growing along the Willamette River in February this content. Green is not always “green”!

My further comments on Policy 5.45: “Greening the built environment” should make clear that green is not always “green”. We have a number of trees and vegetation that actually threaten watershed health and community livability rather than benefit it.  This policy needs to be more explicit on what is green.

I realize that with global warming, plant zones are changing. That doesn’t mean that we should be welcoming more alien ornamentals from all over the world. Rather, we might monitor the robustness of our native species and possibly look to bring in more species from areas of southern Oregon or northern California. 

Policy 5.46 Commentary: (Policies in the Working Draft have commentaries on the left pages) Habitat and wildlife‐friendly design, promotes development that integrates green infrastructure, habitat‐and bird‐friendly design, and the use of appropriate, NON-INVASIVE PLANTS (emphasis mine) for pollinators. . .

Change to:  Habitat and wildlife‐friendly design, promotes development that integrates green infrastructure, habitat‐and bird‐friendly design,and the use of native plants for pollinators and other native wildlife species.

My comments on Policy 5.46 Commentary: In Bringing Nature Home, Doug Tallamy cites numerous

Photo by Clay RuthThe larvae of native insects need native plants to survive.

Photo by Clay Ruth
The larvae of native insects need native plants to survive.

scientific studies (including his own) to show that even if some of our adult native insect species can use alien ornamental plants, their larvae cannot. Insects need NATIVE plant species to procreate the web of life. Since our native insects are the base of the food chain for birds and many other species of wildlife, they need native plants too. You need to define habitat, at least in part, as native vegetation—in both the commentary and the policies.

Policy 5.46. Habitat and wildlife-friendly design. Encourage habitat and wildlife-friendly neighborhood, site, and building design.

. . . 5.46.b. Encourage the incorporation of habitat into landscaping, sustainable stormwater facilities, and other features of the built environment.

Change 5.46.b to:  In order to provide habitat, encourage the incorporation native vegetation into landscaping, sustainable stormwater facilities, and other features of the built environment.

The Nature PrincipleCov

Louv points out that all plants are not the same in their ability to support food webs.

I’ll rest my comments on Policy 5.46 with a quote from Richard Louv in his book The Nature Principle:

All plants are not the same.  Unfortunately, all plants are not equal in their ability to support food webs.  Food webs develop locally over thousands of generations, with each member of the web adapting to the particular traits of the other members of the web.

I also request that Portland add a definition of habitat in the Glossary that includes native vegetation. 

I’m really not a one horse planner.  I really care about so many other aspects of urban design and development. But I feel that it is so vitally important that Portland planners and designers recognize the importance of native vegetation in achieving the City’s  goals. Unfortunately, such recognition does not appear to be the case at present.  The landscape features along central Portland’s portion of the Willamette River are currently filled with alien ornamentals and its sustainable storm water facilities continue to be filled with them too. Portland has many LEED-rated buildings, but native plants are rare in their landscapes as well. And yet this Comprehensive Plan foresees far more landscape integrated into our built environment.  It is critical to get the policy right and work with landscape architectural professionals and their schools so that we’ll have people competent to implement the policy.

I’ll have more comments on other sections of Working Draft 1, but for now I want to go out and promote this exciting document and get YOU to comment too! Thanks for doing such a great job on so many fronts, Portland planners!

Portland: A New Kind of City I

. . . As of 2008, more people now live in cities than in the countryside, worldwide. This is a huge moment in human history. This means one of two things: either human connection to nature will continue to disintegrate, or this will lead to the beginning of a new kind of city, one with new kinds of workplaces and homes that actually connect people to nature.         Richard Louv, Leaf Litter, Winter Solstice 2012

CompPlanGuideCov

The Portland Comp Plan Working Draft 1 released in January, 2013 begins to envision that new kind of city for this “huge moment in history.” It includes a transportation network that aspires to integrate nature into neighborhoods through civic corridors, neighborhood greenways and habitat connections. By doing that it seeks to: 1) increase people’s access to the outdoors, 2) provide corridors for wildlife movement, and 3) catch and treat stormwater.Its Watershed Health and the Environment chapter encourages the protection/enhancement of natural systems and their role in promoting public health—as you might expect from a chapter with that heading. However the emphasis on “designing with nature” in both its Design and Development chapter and its Transportation chapter is what really sets this plan apart and makes it transformational. It puts Portland ahead of the curve in creating Louv’s new kind of city!

The fact that we have such wise and forward-thinking planners and advisory groups to create such a draft plan does NOT mean that the work is over, however.  The devil is in the details!  So, I hope that you will review those details, attend a community workshop or two, and add your thoughts. Below, I’m sharing some of my own comments on the Comp Plan Working Draft 1 in hopes that you will voice your support for them as well as develop your own points.

I was excited to see the draft Comp Plan promise (p,14) “encouraging building and site designs that have native plants and more permeable surfaces and mimic nature, so that pollutants stay out of rivers and streams.” Only once in the actual policies, however, is there any mention of native vegetation. And that one citation is followed by an exception big enough to let an area that could be a haven for more native wildlife—the west side of the Willamette River from the Steel to the Ross Island Bridges—stand as is: largely bereft of native vegetation.

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It’s difficult to find native plants along the west side of the Willamette River from Steel Bridge to Ross Island Bridge

Policy 4.3 Vegetation. Protect, enhance and restore native AND OTHER BENEFICIAL (emphasis mine) vegetation in riparian corridors, wetlands, floodplains and upland areas.

Change to:

Policy 4.3 Vegetation. Protect, enhance and restore native vegetation throughout the landscape.

4.3a. Riparian Corridors, Wetlands, And Floodplains:  Protect, enhance and restore native vegetation in critical wildlife areas such as riparian corridors, wetlands, and floodplains.

4.3b. Upland Areas:  Protect and enhance native and other beneficial tree species. Restore the landscape with diverse native species including trees, shrubs and wildflowers.

My further comments on Policy 4.3: Since riparian corridors, wetlands, and floodplains are the most critical areas for wildlife they are the most important to be restored to predominantly native plants.  What we plant from here on out along our rivers, streams and wetlands should be native check over here. Remove “and other beneficial” vegetation from the policy.

Chair of the Department of Entomology at the University of Delaware, Douglas Tallamy, in his book Bringing Nature Home argues that if alien species were providing as many ecosystem services in their new homes as they did where they evolved, they would support about the same number of insect species in both areas—but they do not. He states:

For an alien species to contribute to the ecosystem it has invaded, it must interact with the other species in that ecosystem in the same ways that the species it has displaced interacted. . . This contribution is most likely when species have evolved together over long periods of time.

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Tallamy’s slide show at Oregon Community Trees conference left community foresters committed to using native trees.

Upland areas could be separate. I would not argue against enhancing the lives of some non-invasive, non-native trees (such as our large old elms) via treatment. I’m not yet ready to maintain that all of the street trees the city plants should be native—only that many, many more of them should be. Tallamy keynoted an Oregon Community Trees conference last year where he made the same point I’m making–as well as a lasting impression on attendees involved with community trees. “When I talk about the value of biodiversity, he said, I am talking about a natural resource that is critical to our long-term persistence in North America.”

 The Comp Plan needs to stress the need to plant more NATIVE trees and plants in upland areas too.  See my next blog, Portland: A New Kind of City II  for further comments on Working Draft 1 of the Portland Comp Plan.