Ключевые слова: agriculture, annual, bio, biological, botanical, branch, cracks, disc, economics, energy, firewood, flora, forest, forestry, grain, knothole, live, nachhaltige, old, older, plant, ring, rings, strains, structure, surface, sustained, time, tree, trees, trunk, trunks, vegetation, wood, woodgrain, work, working, year, zwerger,