I'm going to page
@Northern Light for his insight here, but I think there should be some sort of City Planning policy that mandates many many more trees be planted in all developments along the 427 corridor than typical.
Would that be an effective measure to combat the air quality of the area?
So far as I know, currently, there are no municipal policies or provincial ones that target tree plantings (public or private) based on combating pollution/particulate matter or the urban heat island. (or that matter even augmenting biodiversity). By and large planting policies, where they exist, are opportunistic, rather than strategic.
The province does have a policy of planting trees on rural farm area 400-series highways ever since the big snow-out on 403 a few years ago near Sarnia.
They now have a policy to plant double-rows of White Spruce to create a barrier to drifting snow.
But no similar mandate exists for urban highways for that or any other reason.
The MTO used to have a mandate to consider pollution and aesthetics when re-doing interchanges. You can see a few that got fairly dense forest treatments in past years.
That policy was canned almost 2 decades ago during a round of provincial cutbacks.
In respect of private development, the City's base-level policies are focused on retaining or replacing trees removed for development (3 for 1), protecting and enhancing ravine areas, stream bank stability protection, and meeting
targets for storm-water run off and permeability.
There aren't, for the most part, tree planting targets for any given development (though, streetscape plans may dictate this in some cases).
There is certainly no geography based idea of requiring greater tree planting of a developer because of greater need in a given area, nor is there any similar focus/target on public sector lands.
In terms of gaining a critical mass of trees in this section of the City, the best opportunity lies in Centennial Park in Etobicoke; and Clairville Conservation area by Brampton.
Both could easily supports several hectares and more than 100ha respectively of additional forest without removing any existing community amenities. Though I'm all for targeting redevelopment or existing parking areas in big box land and at Sherway; but you won't get as many trees on those sites as the parklands I noted and costs will be greater.
