More than 70 years ago, Austrian-American scholar, Joseph F. Rock set out to explore southwest China's Yunnan Province. There he took some 3,000 photographs documenting the local people, their culture and the geography of the province at the time.

Some 70 years later, Bob Moseley, an American biologist supported by The Nature Conservancy, a leading organization in the field, has once again framed the very same mountains and villages in his lens.

The pictures serve to reflect the ecological changes in the northwest part of Yunnan in the intervening 70 years and were the subject of a recent exhibition staged in the province.

Bob Moseley took the Chinese name Mu Bao Shan on coming in China. As chief scientist for The Nature Conservancy's preservation program in Yunnan, his work is to set up a collaborative program with the local government to investigate the natural resources of the area. This is known as the "Action Plan for the Protection and Development of Northwest Yunnan."

Following in Rock's footsteps, Moseley has visited more than 40 villages in Yunnan. He has digitized 50 separate sets of comparative photographs to be displayed in the exhibition. Moseley said "The landscape in Deqine has changed little over the 70 years or so. The forest cover has only decreased slightly and in some areas the vegetation has actually increased. Areas of devastation are rare." Moseley was surprised at this finding as it runs counter to claims he has heard of so called devastating development in western China.

Referring to one particular photograph of the "Tea and Horse Road," an ancient trade route, he explained, "You can see in this picture that the vegetation coverage on the mountain side has changed little." He pointed out the line of the ancient path running covered by greenery alongside the modern road zigzagging its way up the contours of the mountain.

The records show Rock was acting in the capacity of an agricultural commissioner of the United States. He arrived in northwest Yunnan sitting in a sedan chair carried by four people. His party traveled many km on rugged mountain roads. During his 27 years in Yunnan, Rock wrote a number of articles on his travels and took many photos. His work aroused much interest in the West and may even have helped inspire the famous novel Lost Horizon by British writer James Hilton with its wonderful tales of Shangri-La.

Its special geography and climate give rise to a relatively closed ecological environment in northwest Yunnan. Biologists around the world have recognized that its abundance of ancient species, a sparse human population and a general absence of outside impact on the environment have endowed the area with a rich gene bank.

"Twenty years ago when I was at university, my tutor told me of the great importance of the northwestern area of Yunnan to the worldwide ecological balance. So naturally, I opted to work in Yunnan when I got the chance. I think this is a place where biologists might realize their dreams," said Moseley.

Bob Moseley came to Yunnan for the first time at the beginning of 2001. He felt a strong sense of belonging when he found the green mountains, valleys and grassland here are so similar to those to be found around his hometown. And so he settled in well on broad pastureland at the foot of snowcapped mountains.

Photos are commonly used for comparison purposes ecological survey work. The pictures taken by Rock all these years ago have become important reference documents for today's scientists engaged in ecological research.

At first Moseley went out at weekends like a tourist. He took along Rock's pictures, which had been published in National Geography in the United States in August 1926. He tried to seek out the actual places in the photographs.

"I had been going to these places and taking photographs for about a year when I suddenly realized that what I was doing was actually creating a program in its own right," said Moseley. He then sought and obtained the support of The Nature Conservancy for this work.

Using Rock's map of 1946, Moseley looked for elderly local people who can speak Tibetan, Chinese and English to help him find the exact places where Rock had been. He even tried to rediscover the same camera angles.

"The local people have been a great help. They have kindly told me of the geographic changes in the villages, valleys and roads and any changed names in both Chinese and Tibetan," he said.

Moseley spoke particularly highly of the help he had received from Cili Nongbu, a Tibetan who had always accompanied him.

They had followed the old "Tea and Horse Road" beside the Jincha River to the Yongming glacier and even into the remote parts of Dengqin and Weixi. When they went deep into the mountains they would often spent the night in local Tibetan houses. Sometimes they camped in the fields. For Moseley and his guide, dangers such as landslide and even just plain getting lost were to become commonplace.

Some photos show a rapid retreat of snowcaps and glaciers. Moseley is opposed to attributing this to the local impact of tourism. He said, "In my opinion this has been caused by global warming. There is evidence to support this view in the rich vegetation in Kawagebo Mountain. In addition some glaciers have retreated where there have never been any tourists."

Some of Moseley's ideas differ from the views traditionally held by his Chinese counterparts. Chinese scientists have held that the valleys of the Lancang and Jinsha Rivers are not suitable for forestry due to their dry and warm river-valley climates. They view is that the timber resources there are not abundant and so there is little felling. Moseley has pointed instead to the influence of the good practice of the Tibetan farmers. Despite the needs of an increasing local population they have not over-exploited the timber resources.

Moseley said, "The media can be quick to make claims of excessive tree felling in western China but this is not borne out by what I have found. Local government has an interest in developing the economy through tourism and will work to take care of the environment. The importance of ecological protection to the long-term future of tourism is well understood and the work of local government is very important." He added that he also had confidence in the cooperation of central government.

The people of Tibet; the Naxi and Lisu ethnic groups; their homes, villages and places of worship; all these have attracted Moseley's attention. In the eyes of an ecologist, the cultural practices of an ethnic minority can bring important influences to bear on the social ecology. So Moseley's photographs are not only of the natural environment but also include the people.

"Rock took pictures of three young people in a Tibetan village," said Moseley speaking at the exhibition. Pointing to one group of photos he said, "I have included three young people from the same village in my pictures. There is little difference in the past and present photographs. The old tree at the entrance to the village is still there. The only change is that the young people of today are dressed in Chinese tunic suits and yellow sweaters. Their smiles can be seen to be as sincere as always. The only difference might be a sense of curiosity which can be seen in their eyes, while the smile of their predecessors of 70 years ago radiated with a greater health and confidence."

Moseley now spends most of his time in Yunnan. Besides his dedication to taking photographs and researching the flora of Yunnan, he is an enthusiastic rock-climber. During his vacations he likes to go climbing with like-minded friends on the Sleeping Beauty Mountain near Kunming, the capital city of Yunnan Province.

However, his biggest hope is to trace all the places where Rock had been and so complete his "photographic exhibition of ecological change in northwest Yunnan."

(china.org.cn translated by Zhang Tingting, October 30, 2002 )