A commentary by a professional urban forester who works frequently around trees and development in Victoria.
The analysis mentioned in the Dec. 29 commentary “Density can mean more homes, more trees, more parks” highlights how simplistic urban forest measurements can lead us all astray.
Conclusions that urban forest canopy growth and increasing building density are proven to be harmonious are to be expected, as those same conclusions were originally produced in a 2021 City of Victoria media release.
For the 60 soccer field (111 acre) urban forest canopy area increase referenced to illustrate the sustainability of development in Victoria, the devil is in the details.
City of Victoria requested and received third-party technical reports that measured urban forest canopy change over two sample periods.
In 2007-2013 and again in 2013-2019, high accuracy aerial remote sensing imagery was analyzed to produce an urban forest canopy baseline for managers to understand tree density at the neighbourhood and city scale. This also enabled managers to interpret how new building development was changing tree canopy density over the sample period. The detailed measurements and methods used in those two canopy analysis reports have not been made public by the city.
Those details revealed in a freedom of information request include numerous measurements which should give an urban forest manager reason to pause pending the analysis of future sample periods.
The decision to produce a statement on the canopy gains in 2013-2019 in what can only be described as a mission-accomplished media release has now backed city staff into a corner.
Distant early warning indicators of deteriorating distributional access to urban trees (and the benefits derived from those trees) are illustrated in the technical report. For example, downtown and Harris Green saw their plantable space area reduced by 15 and 21 per cent respectively. These are areas that are already disproportionately characterized by heat-absorbing concrete, which is a matter of concern for public health as severe heat days are increasingly likely in the region.
This is not to suggest that building density be avoided, but that we build intentionally with long-term public health outcomes in a changing climate as a guiding principle.
The author of the technical report provides a more cautious outlook on the city-wide canopy growth: “It will be of importance to monitor the continual changes in the city’s vegetation canopy to assess whether the fill in growth of existing and new plantings will continue to outstrip the vegetation loss.”
A commitment to fund ongoing canopy analysis using similar methods from the baseline study, and making the full scope of measurements publicly accessible could be valuable gestures on the city’s part recognizing canopy measurement is not a single event but an ongoing pulse check.
The hyper-local distributional benefits delivered through urban trees are persuasively illustrated in research, so much so that in 2023 the Biden government signed into law $1.5 billion in funding for U.S. urban and community forestry initiatives that are equitably focused.
Local-level health and wellness issues for people systemically and chronically exposed to severe heat, noise, pollution, and feeling unsafe being outdoors near their home are problems that carbon storage and greenhouse gas reduction equations are not equipped to solve.
Efficiency and cost savings in the production of new housing come through decisions to innovate and by practising and refining those innovations. The same way innovations might benefit the safety of workers on the jobsite and produce fewer injuries combined with windfalls of savings, we might also learn that housing affordability is directly tied to urban forest enhancement.
Those innovations require early adopters and ongoing patience and have the possibility to provide enormous community benefit at a relatively low cost.
The ongoing appetite to capitalize and politicize low-hanging urban forest fruit is a missed opportunity to move the needle on housing shortages and costs, and for the overall sustainability of Victoria’s urban forest.
The complex systems at work in housing and urban forests are not ones that benefit from simplified measurements and rushed interpretations.
What gets measured in 20 years from today by City of Victoria in terms of urban forest canopy will have a distinct relationship with how the whole of the community, developers, and urban foresters collaborate, innovate, and plan in the months ahead.
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