Hazelnut american, witchazel, pagoda dogwood, depending on how much shade some of the transitional woodland species that you would find in woodland clearings mixed light/ shade/ virginia creeper , vitis grape sp.

talk to a native tree nusery they could give you further info

look @ "acorus restoration" for starters they are in southern ontario near simcoe many, many species.

if you want more links to native nurseries just email me

jeff

The fibrous roots of the silver maple that suck up all moisture and nutrients are a major problem. You might get virginia creeper or grape established, but I doubt witchazel or dogwood would survive. I once got Liriope spicata established under a silver maple, but it took a long long time.

I've actually got a huge red-osier dogwood under one of the maples already. It's been doing great for about 25 years. But it went in around the same time the maples did.
Virginia creeper and grape are no problem...but I'm hoping to establish some shrubs to form a bit of a windbreak to protect the rest of the area.
I've had some success with snowberry (Symphoricarpos albus) so far, but I'd like to get a bit more variety going.

My understanding is that you will have to take some care not to kill the tree with too much soil and root disturbance. So I am not sure if is is feasible to plant large shrubs for a windbreak. That said, aucubas,nandinas, mahonia all survive in my zone (7) under a silver maple but I don't know if you would have to start with very young shrubs (suited to your zone) and wait a long time for them to grow up.

By only adding a couple inches of compost and mulch I have been able to grow vinca groundcover, daylilies and small low-spreading nandina shrubs, and a few other tough perennials, under my silver maple. Because I'm not ready for it to keel over yet I have been trying not to go wild with planting large or deep things since they would require more soil. I also am using a couple of large planters under the tree. This is easier in my zone because many trees and shrubs are winter-hardy in containers here, but containers are one way to get instant height under a tree.

I may be being overly cautious but have been warned that the tree may suffer but I may not know it until some years later.