Explaining that it was a gradual process, the book says: “Man has persistently interfered with the natural vegetation, mainly in order to expand his farming and pasture area, but also to obtain building materials and fuel for his fire. ”
Menurut buku itu, prosesnya terjadi secara bertahap. ” Manusia terus menerus mengganggu kelangsungan hidup tanaman, terutama untuk memperluas lahan pertanian dan tempat ternak merumput, dan juga untuk mendapatkan bahan bangunan dan kayu bakar. ”