"How will a harvest effect wildlife in general?"
In a mature woods, there is very little forage in the under-story for any critters. It just won't hold animals. By creating sunlight gaps after a harvest deer and other animals browse on the fresh tops. They also have new places to shelter in and around the top wood. Once the sunlight gets in and the forest begins to grow again, it starts to thicken up and create more shelter after the tops have rotted away. The wood left after logging also protects young trees from deer being able to browse on them. The branches from the fallen top allow sunlight to filter thru, but the deer can not reach them. The rotting top wood also creates food and homes for smaller organisms that the larger animals eat. Worms and insects that break down the tops thrive and are eaten by mice, whom are eaten by hawks and owls, etc. The life cycle flourishes and continues.