So the people deliberately burned the food supplying hazelnuts etc. to farm? Hazel's are in the birch family, and are fire resistant. They will reproduce through rhizomes in the root system, becoming the dominant species with repeated burning over a long period of time. With very significant hazel and acorn processing spreads across mesolithic Europe, it seems likely such trees would be protected if not deliberately propagated. They would be important for food, fuel, and crafts. Domesticated animals could be run in between trees, fed by them, or communities could grow other plants in between trees. I would love to hear a lecture on the topic for or against!