A global shortage of wood and soaring prices are threatening Japan’s lumber industry and has business operators fearing serious damage to the domestic market. With demand rising in the United States and China, where the national economies are picking up, lumber prices have skyrocketed and Japanese firms are struggling to procure material.   “I am not sure how long this is going to go on and how it will affect wood demand in Japan,” said Katsumi Tannaka, president of Butsurin Co., a Tokyo-based trading firm specializing in lumber.  “The next thing we know, people may ...