https://www.qdma.com/dont-fear-reaper-timber-harvest-good-deer/

Specifically this section:

When a clearcut or opening is first planted in pines for timber production, quality deer habitat is the result – for a few years. Unless herbicides are used to prevent them, early successional plants will produce dense cover and forage among the young pine seedlings. Then the pine trees meet, darkening the ground, and soon nothing is being produced in this stand except pine straw and shade. In this stage between planting and timber harvest, many landowners turn the pine straw into cash, but if your goal is producing high-quality wildlife habitat, dense mature pine plantations are mostly wildlife voids. They are empty zones that deer and turkeys sometimes pass through but do not use (see the photo above, taken at our farm, to see what I’m talking about). - See more at: https://www.qdma.com/dont-fear-reaper-timber-harvest-good-deer/#sthash.K5MsLbry.dpu

Things that grow in the ground are good for deer. Herbicide treatment prevents that growth. I guess it's a "weigh your options" type deal, whether you want good initial timber growth or good initial natural browse for deer and that comes up in a clear cut.