Camp and cook fires constructed of wood are no longer a recommended practice. It has been discovered that the over gathering of wood from the ground is detrimental to the environment, that the increased burning of wood fires adds to the pollution of the air, and that scars left from burning fires directly on the ground or in the ground can have lasting effects for more than decades. Many parts of the world restrict the types, locations, and general use of an open-flame on their outdoor recreational lands.