In fact, I recently passedd the same spot and was taught a lesson in regeneration. The seeds from this tall grass may blow away with March winds if the blades remains standing tall. While it is good for some of it to blow away and disburse to start new colonies of grass, there is the risk that none of the seeds will land on a spot that suits them so perfectly as does this small spot in the woods. The grass needs to have a way to be sure that most of its seeds will land close by where it has already been proven to have good growing conditions. A good way to assure that is snow, snow and more snow.
Snow is a good gentle weight on the grass. This year it was a consistent weight also. We had snow on the ground every day but one in February, resulting in the grass being bent as seeds were pressed into the earth below. The dirt turned to mud under the snow as the ground changed from frozen to thawed and back to frozen. The weight of the snow assured that many of the seeds would stay close to the parent plant. The spot was barely recognizable as I walked past. It looked more like a home for a small tribe of people living in brown teepees scattered across the ground under giant trees. As I walked across the area, my feet pressed seeds into the mud under my shoes.