seem to support much in the way of flowers. The bush around me contains wild roses and some wild clover.
My question is this, how do I know if this type of environment contains sufficient flora to support one or more bee colonies? .
You are in Canada. It has true winter and cold spring.
A couple of acres means nothing to bees. They fly at the distance of 1-3 kilometres. When you calculate how many acres that radius has you see the meaning.
But at spring bees need willows. Often they are not able to fly long distances. Some huge willow trees gives a lot of pollen. We have Salix caprea. It is a tree and the first one to give pollen. Some willow trees are 10 meters tall and even more.
There are too many better willows to flower. When you give fertilization to willow it flowers 3-4 fold more.http://www.bioresurs.uu.se/myller/skog/skog_bild/hansalg.jpg
Weepy willow in Canada, but does it flower a month later than the early ones? http://www.treecanada.ca/images/tree_images/large/Weeping%20Willow%20at%20sunset.jpg