A Broader PerspectiveĪ slew of studies have been written on the detrimental effects of sika deer, linking them to crop damage, bark stripping, soil erosion, car accidents, and reduced tree diversity. The estimated population now exceeds three million, according to Japan's Ministry of the Environment. Sika deer expanded their range by 70 percent from the 1990s to 2009. "The management and production in these plantation forests had become too expensive to compete with the costs of imported timber," explained Sándor Tóth, a forest scientist at the University of Washington who has researched extensively in Japan. But in 1964, restrictions on lumber imports were lifted. Rebuilding after World War II, the nation embarked on a program of replanting native forests with commercially valuable Japanese cedar, cypress, and larch trees to create a self-sufficient timber industry. The remaining 40 percent are plantation forests. About 60 percent are considered natural forests, left mostly for nature to manage. Nambu and other wolf supporters see predator reintroduction as a solution to the overpopulation of deer.įorests cover fully two-thirds of Japan but they have a complex history. "You're up to your waist in this stuff and the trees just can't regenerate through that," Abrams said. Marc Abrams, a forest ecologist at Penn State University, explained that deer browsing prevents young seedlings from taking hold, and has allowed strong, resilient sasa bamboo to take over the forest floor.