DUNHUANG, China — In the cool shadows of Cave 98, Li Lingzhi watched as workers in blue suits inspected the Buddhist frescoes commissioned in this Gobi Desert cliff grotto more than a millennium ago by a local ruling family.
It has taken a decade to restore the cave. Metal scaffolding still surrounds the central statue, a three-story seated Buddha with orange robes.
“We’re waiting for an expert to inspect this, and then we will discuss when we can open it to the public,” said Mr. Li, who works on conservation for the Dunhuang Research Academy, which has managed the Mogao Caves for the central government since 1944, even before the Communists took power. “We’re monitoring humidity and temperature now in this cave.”
Such is the delicate work that goes into preserving these small, centuries-old caves, with nearly 500 of them providing a time capsule of art along the Silk Road and ranking among the world’s greatest Buddhist treasures.
There are statues and figurines and frescoes of Buddha with curly hair and sharp noses, a style common in ancient Central Asian art; Tibetan-style bodhisattvas with a thousand arms drawn in the time of Mongol rule; and disciples wearing Indian dhotis. Most of the caves with art were paid for by royal families seeking a place for private worship. The oldest one dates back 1,600 years.
The caves marked the western frontier of Chinese empires and the eastern one of Central Asian kingdoms. Camel caravans crossed the Hexi Corridor here laden with spices, silks and scriptures, some of which were deposited in the famous library cave that drew the explorers Sir Aurel Stein and Paul Pelliot in the early 20th century. An entire school of scholarship called “Dunhuang Studies” has sprung up in the decades since, and the area has been designated a World Heritage Site by the United Nations.
这些洞窟曾处在历代中华帝国疆土和西方的中亚王国接壤的地方。当时穿梭于河西走廊的骆驼满载着香料、丝绸、经卷，有些经卷原先保存于著名的藏经洞里，正是这个洞窟吸引探险家奥雷尔·斯坦因爵士(Sir Aurel Stein)和保罗·伯希和(Paul Pelliot)在20世纪初来到敦煌。一大批被统称为“敦煌学”的学术研究在之后几十年陆续涌现。这个地区也被联合国列入世界遗产名录。
But the modern era’s threats to the art have been legion: sandstorms, rainwater, local tomb raiders, plundering foreign archaeologists (Messrs. Stein and Pelliot among them), and White Russian soldiers who once lived in the grottoes.
Scholars and preservationists now warn of an even greater looming threat: tourist hordes, even beyond the thousands of daily visitors who flood the area between May and October.
Officials in Gansu Province, which includes Dunhuang, and a company in Beijing have drawn up plans for a sprawling theme park connecting the caves with a separate area of sand dunes that already exists as a tourist playground (think dune buggies and camel rides). The connecting strip of desert would be filled with faux temples, folk villages and souvenir stands.
“We hope it won’t become reality,” said Fan Jinshi, 76, known as the “Daughter of Dunhuang,” who has worked at the academy since 1963 and directed it for 17 years, until March. “The Mogao Caves are irreplaceable and nonrenewable. Not only do the caves have to be respected, but the atmosphere around them must be protected, too. The atmosphere around them is part of their integrity.”
He Shuzhong, founder of the Beijing Cultural Heritage Protection Center, a nonprofit preservation group, expressed his concerns in an essay in the March issue of World Heritage Magazine, a publication of the Chinese Foreign Ministry.
“For 20 years, the city has never stopped trying to exploit the caves for money,” Mr. He said in an interview. “The plan would destroy the environment of the caves.”
The plan, requested by Gansu officials, was completed last October by the Boya Strategy Consultation Group, a Beijing-based company that develops commercial tourism sites across China. The proposal has circulated among Gansu officials and the Dunhuang Research Academy, but it has not been publicly released.
In the plan, Boya designers list various shortcomings in the area around the Mogao Caves, including a lack of hotels, live entertainment, large shopping areas and bus parking lots, according to a copy obtained by The New York Times.
The plan proposes building a trailer park and campground complete with a drive-in movie theater, a vineyard and wine cellar, and a “Silk Road Village” between the caves and the sand dunes with hotels, shopping malls, museums, performance halls, restaurants, bars and movie theaters.
Its authors give generous estimates of potential income. By 2017, it says, the main tourism zone will attract more than 2.13 million tourists a year, with revenue of 496 million renminbi, or $80 million. By 2020, the revenue will grow to $123 million.
“The concept of the tourism zone was suggested by the provincial government after it established a tourism industry leading group,” said Dou Wenzhang, a Peking University business scholar who founded Boya. “The goal is to establish 20 of these zones across Gansu Province.”
Jiang Jianhong, director of daily operations at the Dunhuang City Tourism Bureau, said, “There is no timeline as to when construction will start on the tourism zone.” He added, “Protection of the caves is of the highest importance.”
Perhaps most worrying to the Dunhuang Research Academy, the plan calls for the creation of a provincial government commission to oversee tourism, potentially stripping the academy of some or all of its authority. Mr. Dou argued that the academy would retain much of its power and that its rules on tourism would be respected.
In the eyes of Ms. Fan and her colleagues, the imperatives of preservation must be placed well above tourism. Already, the number of tourists generates anxiety at the academy. After 1979, when the caves were opened to the public, 10,000 to 20,000 people visited annually. In recent years, the crowds have sometimes reached that number in a single day in the peak season, with a total of 810,000 last year.
Ms. Fan and her colleagues worked for years on a plan to control tourism that is just now taking effect. The academy built a new visitors’ center about 10 miles north of the caves. People park there and are required to watch two 20-minute films about the caves before taking shuttle buses to the site. There, guides lead groups of 25 people in tours of one to two hours through about eight caves, with a limit of 6,000 visitors a day.
One of the films, in 3-D, is projected on the inside of a dome that brings the viewer into six caves, including one with an 85-foot-high sitting Buddha.
“The point is to have people look at the art but without going into the caves,” Ms. Fan said. “This is the first place in all of China to experiment with this method.”
About 80 percent of the caves are less than 85 square feet and cannot accommodate many visitors, yet 1,187 people bought tickets for the tour one recent day.
Their mere presence can be harmful, raising the temperature and levels of carbon dioxide and humidity. Sensors in the caves send readings to the academy’s control rooms. If those exceed recommended levels, the academy temporarily closes the cave.
“If there are too many tourists, the already existing conditions will worsen,” Ms. Fan said. “If you develop just the tourism industry and sacrifice cultural relics protection, the profit will run out quickly.”