Generally it is put there to keep animals from climbing up the trees. Squirrels for example, will eat all of the nuts and fruit out of a tree. If you put up sheets of metal about 4 feet off the ground, it will keep them from being able to climb up.
steel
Iron
because its a strong metal
Any metal that isn't too soft can be used. Stainless steel, regular steels, brass. Even aluminium. Titanium can be used as well.
Metal plastic and all sorts of manufacture
the native Americans used trees to make canoes. but trees were also used to make ships, houses, and used as fire wood
Approximately 100 trees are typically used to make a cord of wood.
Trees make paper when they are cut down and processed into sheets. This process involves bleaching the wooden sheets white.
penis metal
wood from the acacia and date palm trees made into charcoal. Charcoal can be made to burn hot enough to smelt metals, including iron, from their ores and to work the finished metal.
Silicon is the non-metal used to make micro-chips for computers/electronics.
Metal rust will not harm trees. There are a number of fungus rusts that can harm plants but they are not metal rusts.
Drills, metal tubes and buckets.
They are used to make furniture, make money and stuff.
All satelites are made of metal.
Yes trees are used to make diapers, as well as crude oil for the plastics that are in them. glue and elastic are also found in diapers.
Epsom salt is also known as magnesium sulfate. The metal that is used to make these salts is magnesium. Magnesium is an earthy alkaline metal.