For years, there have been conversations about what to do with the Norway maples that line SW Broadway Avenue through campus. While their foliage is beautiful, it’s a classic tale of monoculture; they were all planted at the same time, and now they are simultaneously aging, in poor health, and need to be replaced. PSU is using this as an opportunity to consider a new way to think about our relationship to ‘street trees.’ The result of these conversations is an exciting new project: the Broadway Arboretum. Just weeks ago, 15 trees were planted, marking the first key phase of making the Broadway Arboretum reality.
By replacing the old Norway maples with a variety of tree species, the Broadway Arboretum will offer a more diverse and resilient collection of trees along the busy thoroughfare of SW Broadway between SW Market and SW Jackson. Moving beyond a routine replacement of unhealthy trees, the Broadway Arboretum will maximize the benefits of trees to the PSU campus and region. These benefits include different and enhanced ecosystem services; a landscape that is more maintenance-friendly; and the creation of a destination in its own right, an arboretum that will flourish for many years to come, connecting visitors to the urban ecosystem.
Many stakeholders have played a role in the Broadway Arboretum so far, including those typically responsible for the planning and maintenance of outdoor spaces on campus. Several departments within Planning, Construction and Real Estate (PCRE) are involved, including the facilities landscaping team, the Campus Planning Office, Transportation & Parking Services, and Campus Sustainability Office. PSU stakeholders have also consulted the City of Portland, landscape architecture firm 2.ink Studio, and arborists from Bartlett Tree Experts. Laying the foundation for focusing on ecosystem services as part of the outcome of the Broadway Arboretum, Environmental Science & Management students and professor Jeff Gerwing used a tool called i-Tree in 2019 to determine the baseline ecosystem services provided by the Norway maples being replaced. All of these voices combine to create a tapestry of ideas and solutions for transforming a typical downtown landscape into an arboretum; a space for learning, exploration, and connection to the natural world.
This diverse team of professionals adds a lot of energy to the project. Furthermore, there is potential for research about the impact of these choices on campus and on the wider community. How will the new trees impact ecosystem services from PSU’s urban forest? Are there other benefits or consequences as a result of these choices that we can track over time? Core to the arboretum vision is using the opportunity to test and observe the varying tree species. What trees do best in front of retail spaces? Which ones can hold up to lots of foot traffic? Which trees support pollinator or native bird populations?
As the project evolves into a multi-year plan for a more resilient and diverse tree population on SW Broadway, the potential for the impact on the university and wider Portland community is exciting. With Phase I wrapping up with the trees recently planted in December, the hope is to keep momentum going and get Phase II underway. The outcomes of a project like this are wide-ranging and include a variety of opportunities for the community at large, for research and learning, for a tangible ecological impact, and for a lasting legacy for all to enjoy. We can’t wait for the day that taking a break on campus will become synonymous with saying, “I’m going for a walk in the arboretum."