Some of the only intact urban habitat is where it is literally too hard to build

An accidental ecosystem: Willamette Bluffs    

Here intact woodlands can be seen snaking around the contours of the steep willamette bluffs in North Portland. Photo courtesy Google Earth

A greenway containing some of the healthiest intact Oak woodlands in the metro area and home to birds of prey, deer, coyotes, and bobcats frames north portland’s western edge from St Johns to the Fremont Bridge, and yet most Portlanders are unaware of its scope or diversity. The Willamette Bluffs are an expression of passive sustainability for the extreme incline of the cliffs has made development of them all but impossible since Portland’s inception.

A typical section of the bluffs, illustrating the steep gradient that is conducive to dry forests and not human development.

It was no act of altruism that preserved this treasure, just man’s inclination to take the path of least resistance. The result of this is an 11 mile long, incredibly thin slice of the ecosystems that once covered the area. Like all cities Portland lacks connectivity corridors between its parks, but due to the continuity of the bluffs steep grade, they remain incredibly un bisected by roads and trails given their position between industrial swan island and heavily developed north portland. Having an intact migratory corridor was definitely not on the minds of city planners and developers during portland’s turn of the century growth, but were simply created through omission.

The section of the bluffs I’m not considering in my analysis is the portion north of University of Portland known as Baltimore woods. This section is less steep and therefore has seen development, bisection by roads and railways and as a result a more aggressive incursion of invasive species. Active sustainability can be witness taking place here as the community has rallied to preserve and restore this section. I mention it because It is an interesting contrast to the main southern portion encircling swan island, where human degradation and disturbance never really took place on the same level, and where the ecological health will probably forever be superior to Baltimore woods regardless of  how intensive and scientifically sound their restoration efforts may be.

Restoration taking place in the Baltimore woods section of the bluffs. With a few recent exceptions the majority of the bluffs have not needed or warranted human intervention on this scale, which would be more of a disturbance than a help. Photo Courtesy Port of Portland.    

Owens would be particularly keen on this model of sustainability as it aligns with his own borderline misanthropic view. Owens believes sustainability needs to be thrust on humans through circumstance, a worldview I don’t always agree with, but in this case it holds true. I couldn’t help think of him describing Manhattan's green infrastructure being the result of a series of circumstantial factors like the geography of the island and the ease of walking relative to driving, and not tied to smart planning or morality. I believe Owens would find the accidental success of the bluffs to be ideologically affirming.

Can this model be replicated in other parks in the city, the short answer is not where development has already taken place. Connectivity on this level in an urban area could only be achieved by bulldozing houses between existing parks, and even then newly planted restoration projects can never approach the ecological viability of an area that has been left alone. We can look at these unbroken urban green corridors as we grow outward. We must resist the urge to exploit every parcel of land that is deemed easiest to develop. If we plan a new community, instead of razing everything then building disjointed smaller parks from the ground up, look at what greenways and habitats already exist and weave them into the fabric of the new community in a way that is good for people and wildlife.

View of the bluffs looking south from University of Portland with Swan Island industry in stark contrast to the greenery.

Extreme gradient of the bluffs, taken from the Waud Bluff trail. The newly constructed trail connects University of Portland with Swan Island, cutting the commute of many swan island workers who live in North Portland who formerly had to circumvent the bluffs for miles and now can bike or walk to work. The trail may actuate more recreational development and community interest in the bluffs, perhaps to the detriment of the formerly undisturbed ecology.

Healthy Oak Savannah like this were once extensive in the easily developable and farmable land in the Willamette Valley and have seen a 95% decline in Oregon. As a result they essentially only remains in hard to exploit places like the steep Willamette bluffs.