A high forest, or tall forest, is the spontaneous development of natural woods, in which plants reproduce from the seeds produced by adult trees, growing in openings such as those left by the collapse of large trees. In particular, the seed of a beech tree is contained in a spiny husk and takes the name of beech nut. These fruits have a high content of oil and are also used as food. A high forest is natural if it develops from seeds produced by the plants surrounding it. On the other hand, a high forest is artificial if it is man-made by sowing seeds produced from forest nurseries. A high forest supplies lumber, wood as an energy resource, fruit, mushrooms and game, as well as material for the so-called "environmental services". By cutting forest trees down, men artificially create the light conditions for the development of a new generation of trees produced from seeds.