Around here in NW Missouri, If the farmers hay the ground at the right time, in the regrowth, there is a lot of big Bluestem, and gamma grass. Had a conversation with a farmer just this week, he said 2 years ago, they cut hay, and round baled it, got busy with other things, and it sat in the pasture, awhile, killed the cool season sod underneath. After they moved them, pure stands of big bluestem came up, in all the spots. It remains that way today. Seed laid dormant for he estimates 40 years! Obviously the prairie is waiting us fools of the poor land management out, I'm comforted by the knowledge.