It absolutely takes decades for trees to decompose. This is just one study of many: > In woods stretching from Minnesota to Maine in the north and from Louisia

It absolutely takes decades for trees to decompose. This is just one study of many: > In woods stretching from Minnesota to Maine in the north and from Louisiana to Georgia in the south, technicians catalogued every downed log they found. They ranked each log on a scale of one to five, from freshly fallen to badly decomposed, and then returned to the same forests five years later to revisit and reassess. Using these figures, the researchers were able to create a model of decay for 36 different species of trees. “Some people said it couldn’t be done,” said Woodall, “but we did it.” > The computer model calculates that the “residence times” (how long a tree will take to completely decompose) for conifer species range from 57 to 124 years, while hardwood species are typically around on the forest floor for 46 to 71 years. https://northernwoodlands.org/knots_and_bolts/tree-falls-in-a-forest https://northernwoodlands.org/knots_and_bolts/tree-falls-in-... Note that these estimates are for trees that have already fallen to the forest floor. It's common for trees to stand for decades after death, especially in dense forests where they have other trees to lean on.