Devices that are attached to boots and used by tree workers to aid in tree climbing
Tree spiking involves hammering a metal rod, nail, or other material into a tree trunk, either inserting it at the base of the trunk where a logger might be expected to cut into the tree, or higher up where it would affect the sawmill later processing the wood. It is used to prevent logging by risking damage to saws, in the forest or at the mill, if the tree is cut. The spike reduces the commercial value of the wood by causing discoloration, thereby reducing the economic viability of logging in the long term, without threatening the life of the tree.
It is believed that tree spiking originated in timber logging labor disputes in the Pacific Northwest of the United States in the late 19th century. It came to prominence as a contentious tactic within unconventional environmentalist circles during the 1980s, after it was advocated by Earth First! co-founder Dave Foreman in his book Ecodefense. In the book, he discusses how to do it and how to avoid risks to the activist and the logger.
In 1987, California mill worker George Alexander was seriously injured when the bandsaw he was operating hit an 11-inch spike embedded in a 12-inch trunk with a worn-out blade he had earlier requested to be replaced. This event led the leader of Earth First! to denounce tree spiking.
Other activists were led to either reject this form of sabotage entirely, or take some precautions, such as putting warning signs in the area where the trees are being spiked. Tree spiking is labeled as eco-terrorism by logging advocates who claim it is potentially dangerous to loggers or mill-workers, although only this one injury resulting from tree spiking has been reported.