It is prohibited to bring birch mushrooms. According to the query "People's Republic of China *** and the State prohibited to carry, postal entry of animals and plants and their product catalog" that the birch mushrooms are "People's Republic of China *** and the State prohibited to carry, postal entry of animals and plants and their product catalog" in the prohibited items, if you carry will be detained and destroyed. So the airplane is prohibited to bring birch mushrooms.