Dave Demers: Hell strips, designed ecologies, and supercharged Nature—more tools to fight climate crisis

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      By Dave Demers

      As our city misses the mark of becoming the greenest, the park board plows ahead. Recent initiatives—planting tens of thousands of trees, swapping gas-guzzling for emission-free landscape equipment, restoring our coastline—are direct ways we are tackling the environmental crisis that’s been building for decades.

      The plantsman and commissioner in me wonders: what other biocentric, parks-driven means do we have to help make this a healthier city, a richer biosphere?

      Here I propose we investigate ways to upgrade some of our marginal landscape in order to optimize its biological output and overall connectivity. Simply put: strip some of that little-used grass and replace it with smart, high-impact plantings.

      Let’s be warned though, for this city is quite the artificial system, which forces us to look beyond our eco-nostalgic ideals and onto complex "designed ecologies". Copy-pasting a chunk of geographically-specific plant communities onto our urban fabric, as per the conventional attitude toward habitat restoration, is in many instances an oversimplification of a complex undertaking.

      Here I wish to make the case for a fuller ‘toolbox’, one that contains native plants as well as some "near-natives" and exotic species. Let’s dig in.

      Marginal landscape reclaimed

      Marginal landscape is defined as the byproduct generated by urban development: that city-owned space along roads, the right-of-ways, the tree pits, and the roundabouts. From the scenic median of the Cambie corridor to the most widespread grass strips wedged between sidewalk and curb, such space is as high-profile as it is ubiquitous, and mostly underused. These skinniest of fingers form a far-reaching network, like a web of capillaries feeding an organism.

      The idea of putting this "left-over space" to greater work isn’t new. The Seattle-based Pollinator Pathway did well in promoting habitat connectivity through the greening of such land, loosely connecting pocket oases to allow wildlife to hopscotch through the city.

      In Vancouver, similar work is accomplished through volunteer-based programs such as the Butterflyway Project and various neighbourhood stewardship associations. Seeing these independent initiatives, I here contend that we need an overarching modus operandi that would allow us to scale up and facilitate long-term management of this hands-on grassroots energy.

      Imposed in some of the most unforgiving growing conditions, plants in this reclaimed space must meet and maintain socially acceptable cosmetic standards, despite the ebb and flow of public resources.

      Given this challenge, the sheer scale, and the very public nature of the undertaking, a solid game plan is strongly mandated.

      Vegetation on New York City's High Line was chosen with a view to what had colonized the former rail line before it was repurposed into a park.
      Beyond My Ken

      The case for designed ecologies

      First, and before any shovels hit the ground, it is important to move the dial of our expectations somewhere between traditional horticulture and conventional rewilding, onto the sweet but elusive spot where greater sustainability, maximum ecological output, and generalized public adoption all overlap.

      With the peculiarities of our urban marginal land in mind, I am suggesting we look at natural flowering meadows for inspiration. (As many have suggested elsewhere: the uncontested leader in this field is the Department of Landscape Architecture of the University of Sheffield.) 

      Many man-made versions of this grass-based plant community have become wildly popular recently, and rightfully so: this particular type of landscape is particularly well-suited to urban greening. Yes, I must name-drop New York’s High Line here, but also Chicago’s Lurie’s Garden and London’s Olympic Park.

      Recent British studies have qualified—and detailed—the aesthetics-based acceptance of such designed ecologies with these results: meadows have a higher preference score than traditional formal bedding and mowed grass; and the tolerance for downtime in cosmetic appeal (a.k.a winter) improved when information on benefits and savings were provided.

      A most interesting finding in here is the correlation between richness and fullness of a studied meadow and increased appreciation by respondents of lower socioeconomics status.

      Another study confirms that more natural-looking plantings are perceived as "significantly more restorative", further corroborating a growing acceptance for a "messier" aesthetic in urban settings.

      Such meadows have the advantage of handling drier and poorer soils with brio, and of climaxing at easily manageable heights. When engineered with a deep understanding of ecological dynamics, such mixed plantings may welcome a staggering diversity of plants, resulting in a prolonged visual feast.

      Furthermore, the functionality and vigour of such precisely crafted plant communities can resist some external disruptions such as weeds and accidental traffic, hence alleviating some of the maintenance burden.

      Unfortunately, there is no one single recipe to ensure success here. This desired outcome requires a remarkable knowledge of plants and their habits, and a precise tailoring to the realities of Vancouver. For this, planners, landscape architects, ecologists, and gardeners are all needed for the job.

      Dave Demers

      Supercharged Nature at work

      As design progresses, most people involved will naturally focus on our native plants. Indeed, natives are the best match to our bugs, bees and butterflies—they have, after all, evolved for each other. The reality is, however, somewhat more nuanced.

      For this city is a far cry from any natural place. Here, abiotic conditions can be harsh: serious heat-island effect, soils spiked with road salts and concrete, hydrology skewed by endless impervious surfaces, air polluted by incessant traffic, and so on. Furthermore, the physicality of whatever space is left for planting has little in common with that of the coastal B.C. of yore. Tight planting areas of limited soil depth are rarely conducive to the full deployment of the oversized generosity of our native flora.

      And in the city, we set the bar high. Most urbanites share a certain conditional biophilic attitude: we expect beautification from our plantings, but never to the detriment of cleanliness, visibility, and safety.

      Plants equipped to perform in such taxing and unnatural conditions may happen to be native, but may just as well be from close-by (near-native) or even from the other side of the planet. Life conditions on skinny boulevards and in tree pits should only worsen as the effects of climate change intensify. So when choosing plants, I strongly believe one should first and foremost have ‘fitness’ in mind.

      Yet what about the fitness of non-native plants to host and feed pollinators and such? A British study from 2015 "identifies that a mix of plants from around the world may be the most effective way to sustain pollinators", adding that "non-native plants can prolong the flowering season providing an additional food source." In short: the greater the diversity and the longer-lasting the flowering, the better the outcome.

      This by no means downplays the primacy of natives, nor the risk of invasion by exotics: each plant addition must be considered and judged with utmost care. It’s about these plants getting along, not overtaking each other. Alien species aren’t all evil: English ivy definitely is, but the Anna’s hummingbird? Far from it.

      Nigel Dunnet

      Packed with benefits

      As we have seen, such novel, supercharged, meadow-inspired plantings are packed with benefits, and two more stand out:

      First, each bit of such planting could become a plank in our own Noah’s ark, to sail through this ever-growing concrete jungle. As per the most recent media shockers, there are reasons to worry for the world’s insect population: 40 percent of all species at risk of functional extinction, due in great part to habitat destruction and pollution (fertilizer and pesticides).

      One of the most alarming facts is that the 40 percent of insects at risk include both "specialist" and "generalist" species. Even more so, certain regions of the world have showed an overall decline in insect biomass of more than 75 percent over three decades. Such a decline is worse than that affecting most vertebrae but one can deduct that it is only a matter of time before full cascading effects kick in. Who remembers those car windshields plastered in bugs of all sorts?

      Second, the omnipresence and approachable scale of these pockets of designed ecologies makes for a perfect introduction to citizen science and hands-on public engagement. Let’s note that the study on insect population decline mentioned above was performed by...a group of amateurs and citizen scientists!

      At the Vancouver park board, "access to nature" is one of our founding principles, and increasing stewardship opportunities are a key priority. From students to retirees, these volunteer gardeners and guardians could be important building blocks in the edification of this project, thus casting deep in its foundation buy-in and support from the community.

      Replacing the dullness of low-use, city-owned lawns with intricate plantings full of life is a potent idea. If at one point the said lawn stood as a democratized signifier of our dominion over nature, the type of plantings I suggest we replace it with could become a token of a solution, a bit of balm accessible to all to help assuage our qualms about this mess we’ve put this planet in.