TOTTORI -- A huge glass dome structure near Japan's largest sand dune houses a research institution to combat desertification -- a serious threat to the global environment. Tottori University's Arid Land Research Center is also developing ways to promote sustainable agriculture in arid areas.

Officials say it is the only such research institution in Japan and one of the largest of its kind in the world.

Desertification is spreading worldwide due to population growth, exploitation of farmland and an increase in livestock. According to the United Nations, 87 percent of desertification is induced by humans and 13 percent by climate change.

About one-third of the world's land surface is covered by arid land, U.N. figures show. Since Japan ratified the United Nations convention on combating desertification in September 1998, the center's role has become more important, says Shinobu Inanaga, director of the center.

The U.N. convention took effect in December 1996, calling for global cooperation to provide financial and technological help to countries fighting desertification, mostly in Africa.

"Many people from those countries which are experiencing problems stemming from desertification have contacted us," Inanaga said. "We would like more people to know about our research."

The center was established in June 1990 as an independent research center of Tottori University. It also serves as a national research institute of the Education Ministry.

Its research ranges from analysis of ground surface information and the response of plants to environmental stress in arid and semiarid regions to measurement and prediction of water and salt movement in soil.

The center upgraded its facilities in 1998 by building a dome-shaped glass house where the temperature is controlled to simulate the climate of arid regions and laboratories that include a specimen display room.

The dome, which is 15 meters high and 36 meters wide, is divided into three sections: a cold desert section, a subtropical desert section and a soil analysis and plant conservation section.

In the subtropical desert section, for example, where studies on the ecology, physiology and production of plants indigenous to subtropical deserts are being conducted, about 70 kinds of trees, plants and crops are planted. The daytime temperature is 35 degrees; at night it is 25 degrees.

A sapling of a baobab tree, native to Africa, was grown from a seed at the center and is now 50 cm tall, according to Tomohide Shimotashiro, a researcher at the center.

"Thanks to the large floor space allocated for this section, we can study the ecosystem of the comprehensive environment (of the subtropical desert), which is home to many kinds of plants, including trees and crops," Shimotashiro said of the 250 sq. meter space. "Before this dome was created, we could only conduct studies on individual plants."

However, the dome environment is not perfect, as humidity levels are much higher than those in actual subtropical desert regions, he said.

In order to inform more people about the center's research and meet public demand, the center has decided to open the facility to the public four times a year.

About 450 people visited the center at the first open house on April 24, officials said. The next open houses are scheduled for Aug. 28, Nov. 3 and Feb. 26.