The long, hot, humid summer is favorable for the development of extensive and varied vegetation. Some 4,500 plant species are known. Forests once covered about two-thirds of the total land area, but, because of fuel needs during the long, cold winter and the country’s high population density, the original forest has almost disappeared. Except for evergreen broad-leaved forests in the narrow subtropical belt along the southern coast and on Jeju Island, most areas contain deciduous broad-leaved and coniferous trees. Typical evergreen broad-leaved species include camellias and camphor trees, while deciduous forests include oaks, maples, alders, zelkovas, and birches. Species of pine are the most representative in the country; other conifers include spruces, larches, and yews. Among indigenous species are the Abeliophyllum distichum (white forsythia or Korean abelia), a shrub of the olive family, and the Korean fir (Abies koreana).
Wild animal life is similar to that of northern and northeastern China. The most numerous larger mammals are deer. Tigers, leopards, lynx, and bears, formerly abundant, have almost disappeared, even in remote areas. Some 380 species of birds are found in the country, most of which are seasonal migrants. Many of South Korea’s fish, reptile, and amphibian species are threatened by intensive cultivation and environmental pollution except in the DMZ between North and South Korea, which has become a de facto nature preserve. Once farmland, and subsequently a devastated battleground, the DMZ has lain almost untouched since the end of hostilities and has reverted to nature to a large extent, making it one of the most pristine undeveloped areas in Asia. It contains many ecosystems including forests, estuaries, and wetlands frequented by migratory birds. The zone serves as a sanctuary for hundreds of bird species, among them the endangered white-naped and red-crowned cranes, and is home to dozens of fish species and Asiatic black bears, lynxes, and other mammals.