Beijing, Aug. 12 - China's environmental watchdog has called for the establishment of a national ecological reserve in Dunhuang, northwest China's Gansu Province, to prevent further environmental deterioration there.An official with the State Environmental Protection Administration(SEPA) made the appeal after news reports uncovered that the ecological environment in Dunhuang continuously deteriorated.Dunhuang was once an important site on the ancient Silk Road, a 2,000-year-old trade route that linked Asia and Europe, starting in Xi'an, capital of northwest China's Shaanxi Province, and ending in Europe after passing through southern and central Asian countries.In 1987, the Dunhuang Mogao Grottoes, also known as the Caves of 1,000 Buddhas, were inscribed on the UNESCO World Heritage List.Surrounded by a desert, Dunhuang has an extremely arid climate and a very fragile ecosystem. Global climate change and human activities have made vegetation decrease there.The official admitted that major rivers in Dunhuang have run dry and lakes are disappearing. Underground water level has dropped sharply and natural disasters such as sandstorm frequently occurred.The deteriorated ecosystem in Dunhuang has threatened the local cultural relics and natural scenery, the official said.Besides the natural factors, defects in the administration of Dunhuang also add difficulties to the protection of the ecosystem there, according to the official.He said that the current administrative system fails to have overall planning for balance among economic development, social development and environmental protection.The SEPA called for local departments of environmental protection to improve environment impact assessment and take measures to restrict consumption of natural resources.A national ecological reserve is urgently needed in Dunhuang to protect its civilization and heritage that has a history of more than one thousand years, the official said.