Bamboo holds topsoil very tenaciously, preventing soil erosion on hillsides and riverbanks. With more than 1,500 species, bamboo is the oldest grass in the world, dating back nearly 60 million years.Liana trees grow rapidly wrapping around any vertical or horizontal support base such as takian or "rain trees". Thus it is dangerous to simply cut a tree in the jungle because it can pull connected liana vines with it creating a cascade of damage.