We’ve been giving a lot of thought recently to the subject of our rapidly changing climate and the related crisis of the 6th mass extinction. As the scale of the problem comes into focus, we recognize our profession is well positioned to step into a leadership role. The American Society of Landscape Architects recently held a summit to redefine our professional mission and published this statement: ‘Climate change, rapid urbanization, loss of species diversity, and inequity make the need for sustainable landscapes greater than ever.’
Everything changes, nothing changes
That is not to say that the longstanding directives in landscape architecture don’t still hold: designing functional, durable, beautiful spaces that suit the needs of the users, and elevate their spirits is still the job. But we’re now tasking ourselves with layering more utility into every design: taking the same budget and space and program and achieving more with it. This strategy has been termed High Performance Landscapes. The parallel effort for the built environment, High Performance Buildings, has been advancing rapidly in recent decades, but to attain a livable future, High Performance Landscapes are a crucial part of the equation.
High Performance Landscapes as we define them produce net positive benefits and products beyond their primary use: benefits such as clean air, wildlife habitat, food, carbon storage, building materials, human mental and physical health and more, and they do this through integrating living natural systems.
Natural systems are best conceptualized by imagining what would have been happening on a site pre-development, including: how water would have been flowing, what plants and animals would have lived there, how soils would have been generated, and even what people might have used or contributed to the site. Natural systems provide services for the ecosystem through a combination of physical and biological processes – and it’s the biological part, the living system part, the self-perpetuating growth, decay, transformation and regenesis, that tends to be undervalued and yet is utterly crucial to life on earth.
Though landscape design has always had a role in the various sustainability rating systems and requirements set by agencies, etc., the potential of landscape architecture to contribute has been somewhat under exploited because of the dynamic, difficult to quantify natural elements in landscape design. For example, the contribution a tree may make to produce oxygen, hold water, provide habitat, sequester carbon, and ultimately provide useful building material is impossible to say when it’s planted. The growth of any one tree is unpredictable. The landscape is also an open system… you design one thing and changes on and off site create another thing. But the potential inherent in natural systems to produce a net positive is boundless… the built environment is at its best on the day it’s built, but landscapes with intact natural systems are perpetual.
We must all become ecologists
Traditional landscape design has often been asked to exclude this dynamic activity of natural systems. As the productive aspect of landscape declined with the move to a modern existence, a taste developed for a tidy sameness that could be easily controlled. Even when the aesthetic desire is more naturalistic, such as in the trend for meadow plantings, it is quite possible to choose plants that will look beautiful in a meadowy sort of way but not actually act as a living system.
There’s been even less tolerance for cyclical natural events like fire or flood. It’s understandable that people have wanted to avoid fire and flood and even maintenance hassles in their gardens, but now that the majority of the world’s landscape is changed by humans, we’re seeing the impact that preventing these processes has over time. From massive wildfires, to loss of pollinators, to silt filled rivers, human interruption of natural processes has gotten us to a place that is threatening our survival and we’ve got to evolve our thinking to allow these living systems room to exist alongside us.
As designers, we need to expand our conception of who we work for to include birds and bats and insects, as well as soil microbes and waterways, and we need to expand our knowledge to match. Designing for living systems in the built landscape requires a specific knowledge of local ecosystems and an appreciation of ourselves as part of it. Designers must be able to answer questions such as: Which native plants can survive in harsh urban conditions? How do we best care for soil? What tree will thrive here in 50 years? Where can I source rock most responsibly? What play experiences are best for children’s mental health?
Adapt or Die
Projections for the Portland area are that by 2080 we can expect a climate like Sacramento’s is today… Which is to say much hotter, drier summers. Already we’re seeing die off of a number of our iconic conifer tree species due to drought and related stressors. Most of the very large trees that we celebrate in Portland on bumper stickers and tattoos were planted a hundred years ago and are rarely planted today as concerns about maintenance, parking, and overhead lines cause people to opt for small ‘well behaved’ trees. But the small well behaved trees don’t offer near the ecosystem services that a large canopy tree does. If we’re smart we’ll follow in Sacramento’s footsteps since they’ve been down this road already. Several decades ago with the close of a power plant they were facing energy shortages and decided to essentially cool the whole city with a massive street tree planting campaign. The strategy worked and the city rebranded itself as the ‘City of Trees’.
When humans are pushed to adapt we can and right now we need to adapt fast, recruiting every idea and solution that we can. We need to push ourselves to consider how to spend precious resources and how to design living systems in between our transportation systems and on top of our buildings and in our parks because we can’t afford to sacrifice the free labor that all those systems do to clean our water, build soil, keep us sane, grow food, house insects… Just ask the Chinese workers who have the seemingly impossible job of hand pollinating fruit trees because the insects that used to do the job are gone.