I have actually started responding to a few posts in this thread but ended up deleting what I started to write, because trying to explain forestry and spraying to non-forestry people is like trying to tell an anti-gunner why we need to own handguns, there are lots of good reasons but they refuse to acknowledge any argument but the ones they believe to be true.
First and foremost I am speaking from an Ontario foresters perspective, NB probably has different policies but I am sure they are similar to Ontario's in the most significant ways.
On Crownland foresters manage the forest to grow a variety of habitats, we don't manage the forest to grow the deer herd. The video with the biologist above seems accurate, what he fails to mention is that much of the failure on crown land to manage for wildlife was his responsibility back when he was a government biologist. Perhaps he did fight hard as a civil servant for the deer herd, but was ignored, because we do not manage forests for one wildlife species.
Past logging practices were basically cut and run, there was always more timber over the next hill to cut. As a result forests were left to naturally renew, conifer forests moved to more mixed woods, mixed woods become more hardwood dominated and hardwood forests stayed hardwoods. While clearcuts do remove trees similar to a forest fire there are big differences, one of the main ones being that fire can effectively kill hardwood and give conifer species a big advantage at regenerating. So if a jack pine stand burns you are pretty much guaranteed a fully stocked jack pine stand, spruce is similar. When you clearcut a similar forest stand any hardwood in the block will generally survive and become a significant component of the next stand.
Historical inventories show northern forests were largely conifer dominated, government policy is to move back to that historical condition. In the 80s we did manage forests to increase moose habitat to make hunters happy, which worked, however it has driven woodland caribou from much of it historic range. So with this change in policy, if we cut a relatively pure conifer stand we try to get it to come back as conifer, if we have a mixed wood we try to bump it back towards more conifer, if we have a pure hardwood stand it is left to come back as hardwood or we may try some interventions to increase the conifer component by a few percentage points. We manage the forest composition. Spraying is one tool that is used to manage the composition. Generally we spray to slow down competing species so the conifers can get established. Depending on a lot of factors, sometimes the spray just slows down the hardwoods which allows the conifer to grow, other times it nukes all the hardwoods.
On private land there is generally no government oversight so it can be managed to the landowners desires. If they want to manage for deer they can. Private land forestry is usually very similar to the old cut and run practices of the past on crown land. Not much thought or effort is put into forest renewal, as a result lots of hardwood and woody shrub species comes back. Hardwood makes very good habitat for deer during the growing season and in moderate winters. In hard winters conifer provides important cover, which hardwood does not, and can make the difference between survival or decimation of a deer herd.
