Here is a story that links events in World War 2 to impacts on tree rings in Norway. According to the story, a German dendrochronologist noted that many trees along the Norwegian coast near Kåfjord. In 1945, the Germans were hiding their battleship the Tirpitz there using chlorosulphuric acid as a sort of “chemical fog” to try to cloak it from aerial enemy forces. The acid destroyed the trees’ needles, shutting down photosynthesis until the needles could grow back. Trees can be affected by this for several years, during which time the growth of the tree, as evidenced in its tree rings, almost stops. The farther away from the hiding place of the Tirpitz, the less the trees were affected. You can read the story at Newser here.
