I thought they would struggle to stay happy with so little light. Good for them.
Ah, light does matter for trees, more for some species than others..........but.........there's a couple of kickers here..........
Where does sunlight come from in Toronto, broadly speaking?
The south; with secondary sun from the east and the west.
So.....let's look at those trees on Lombard and see what their potential sun is, currently?
To the east:
Lots of sun from due east, very little from south-east......some, but not enough........
The West:
Pretty good from due west, but lousy from the south-west/north-west. Ok......
But wait....look at how robust those trees are on the north side............and how small they are on teh south side by comparison, in pretty similar planting conditions.........yet they get similar east/west light levels...........hmm
The south:
Aha! Look at that robust opening for southern sun almost due opposite the biggest trees.
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So sun does matter.
The trees further west on Lombard aren't opposite this opening, so they also get less sun. Improved planting conditions and correct species choice could help address this.
(Basswood and Sugar Maple both tolerate lower light levels well, not complete shadow by any means, but less sun than average, more ambient daylight vs full-sun. )
Sugar Maple, however, is very sensitive to road salt, and requires the appropriate planting conditions.
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In this case, the height of the new complex, being on the north side of Lombard would not affect tree health on Lombard except as it pertains to wind conditions.
It may, however, affect tree health on Richmond, where it would reduce southern sunlight.