Aso-Kuju National Park
Grasslands
The Aso Caldera is one of the largest calderas in the world. Covering a total area of 380 km², the unique landscape is characterized by mountains and grasslands. The grasslands of the Aso Caldera make up approximately 200 km² of the total area. These grasslands are a unique feature of the caldera, with native, semi-natural areas including meadows, pasture land, reed fields (for thatching), marshes, and areas where grasses and plants have been introduced and cultivated.
Due to the geographical location and climate of the park, the grasslands support a diverse range of plants and animals. The Aso grassland area is home to over 600 species of plants, successful livestock and agricultural crop industries, and an invaluable source of water. The area is known as “the thousand-year-old grassland,” but geological evidence in the soil indicates that the grasslands have been cultivated and maintained by humans for at least 10,000 years.
The Kuju Plateau, lying at the foot of the Kuju mountain range, is also known for its broad grassland landscape. The local soil contains pyroclastic sediments deposited by past volcanic activity. The soils here favor the growth of pampas and other tall grasses.
The grasslands are managed as cattle pastures, by mowing, and by controlled springtime burnings called noyaki. Without these methods, trees and shrubs would invade, turning the land into forest, and the natural wealth of the grasslands would be lost.