Mixed deciduous and coniferous forests cover about three-quarters of the land. Most of the country’s old-growth forests were cleared over many centuries for use as firewood and building materials, but they have rebounded since the 1970s as the result of intensive reforestation efforts. The country’s few remaining old-growth forests are protected in nature reserves.

Protected areas make up about 4 percent of South Korea and include more than a dozen national parks. One of the world’s most interesting wildlife sanctuaries has developed in the Demilitarized Zone (DMZ), a border zone that has separated South Korea and North Korea since 1953. The uninhabited zone, about 4 km (about 2.5 mi) wide for most of its length, has become a haven for many kinds of wildlife, particularly migrating birds.

Principal species of trees in South Korea include pine, acacia, maple, elm, poplar, fir, and aspen. Bamboo, laurel, and evergreen oak are found in the mild southern coastal areas. Fruit trees include apple, pear, and persimmon. Woody, evergreen shrubs such as azaleas and rhododendrons are found throughout the peninsula. Another shrub, rose of Sharon, is a hardy species of hibiscus that blooms continually from July through October. It is the national flower of South Korea, where it is known as mugunghwa (Korean for “eternal flower”).

Large mammals such as tigers, bears, and lynx were once abundant throughout the Korea Peninsula but have virtually disappeared due to human settlement, loss of forest habitat, and overhunting. The Siberian tiger has not been sighted in the wild in South Korea since the 1920s; the Asiatic black bear can still be found in some remote mountain areas. Several species of deer are indigenous to the peninsula, including the roe deer, water deer, and Siberian musk deer. The musk deer, which has been overhunted for its musk glands, is legally protected as a threatened species. Smaller mammals indigenous to the peninsula include the wild boar, red fox, badger, rabbit, squirrel, and chipmunk.

Many species of birds inhabit South Korea. The crested lark and several types of woodpecker are found only on the Korea Peninsula. The black-billed magpie is the national bird and commonly sighted. Other common birds include the jay, sparrow, robin, cuckoo, dove, pheasant, snowy egret, sea hawk, and seagull. The country is located on the migratory routes of birds such as geese, ducks, and swans that summer in northern China and Siberia and winter in warm southern climates. Most of these birds stop in South Korea on their way to or from more southern destinations, but the red-crowned crane (also known as the Siberian crane) winters in South Korea’s rice-paddy fields and grassy tidal flats from November or December through March. (Some of these birds also winter in China.) The crane is classified as endangered and is strictly protected.