Celtis occidentalis might work.
Manitoba Maple sprouts like crazy. You might have trouble keeping that under control.
Get some Basswood in there for the
bees. Caragana (I mentioned it earlier) is a nitrogen fixer that
bees will also love. There are wild plums but maybe better to do your homework on them because I hear that many animals will ignore them because they are too bitter. If it were my land, I would plant some wild blueberries near the Caragana. Not for the deer, for me.
I think leaf mulch is better when it has a variety of different leaves. Here are some
trees native to Manitoba:
Manitoba Mapble, Black
Ash, Green Ash (especially good for leaf mulch, drops first), Tamarack, Showy Mountain Ash, Eastern Cottonwood, Balsam Poplar, Hop-Hornbeam, Wild Plum, Bur Oak, Basswood, Hackberry, White Birch, White Elm, Largetooth Aspen, Peachleaf Willow, Trembling Aspen.
Consider black-summer truffle innoculation while planting trees, especially the burr oak. And the bark of oak is also used for cork. And make sure you have a
mushroom you like.
Perennials for the field: Goldenrod, oats, mullein (can this kill
voles?), barley (also use it on algae problems), perennial wheats, comfrey, yarrow, clover (nitrogen), purslane (omega 3/6 fatty acids), calendula.
Wild rice if you have a shallow
pond. Cattail for the muskrats.