Environmental pressures on the world's most populous mountains may be turning them into deserts, scientists and planners warned last week. Overuse of the forests and croplands and attendant erosion in the Himalayan countries of South Asia and in northeast Africa are causing the mountains to lose their ability to support life.
The warnings were heard at the first meeting of the International Mountain Society (IMS), an international organization of scientists, planners, and representatives of national and international organizations who work in development issues affecting mountain environments worldwide. They met last week in New Paltz, N.Y.
Nepal, situated in the Himalayas, is in danger of losing all its forests by the end of this century, and Ethiopia will be in similar straits within 20 years , the scientists said. Farmers in these and other countries are ''clinging to the hillsides with their fingernails, trying to make sense of a harsh environment,'' said John Cool, an associate with the Agricultural Development Council in Katmandu, Nepal.
''Mountain people are isolated. They have no access to markets, to technology , education, or political power. They're often a religious minority or speak a different language,'' said Mr. Cool. The Peruvian alpaca herders speak Quechua, their native language. The Ladakhis, natives of Ladakh, an area of northern India often called ''Little Tibet,'' are a Buddhist minority in a predominantly Muslim Indian state. Their communication with the political majority often founders upon misunderstanding. Yet, said Mr. Cool, ''the future of the mountains depends upon these people. The control of mountains resources is ultimately in their hands.''
''The magnitude of the environmental and economic problems has reached beyond the local peoples' capacity to respond,'' said Jack Ives, president of the IMS.
The group cited some important progress in local resource management. In the village of Thokarpa, in Nepal, the village leader started a tree nursery to grow seedlings in order to reforest dangerously unstable slopes. This was done ''just before too late,'' said K. K. Pandey, a development specialist in Katmandu. Thokarpa is now the model for a nationwide community forestry program in Nepal, sponsored partially by the Food and Agriculture Organization of the United Nations. In parts of Pakistan and India, a voluntary shift from agriculture to tree crops is taking place among the farmers. In the hills of Himachal Pradesh in India, said B. C. Negi, a forestry department official in that district, cultivation of apple trees has superseded grain farming, providing a cash crop and protecting the hills from erosion.
But while some resource management plans succeed, many more fail, and while local people get organized, the forces of gravity and water are taking their toll on the slopes. IMS president Ives said research into the economic, anthropological, and social issues of mountain locales, in addition to and combined with research into the natural sciences, can help circumvent many problems, and he offered the IMS as an ''information broker'' to achieve that end. He says he hopes that by working with organizations at all levels from local to international, the IMS will have a role in helping to stay the ecological disaster that he sees evolving in the mountains.
The mountains of Asia and Africa are the most intensively farmed in the world. There increasing population pressures have pushed farmers up increasingly steep slopes into landscapes that cannot tolerate farming. The soil of their terraced fields can be lost in a single rainy season to erosion or landslide. This causes hunger and deprivation among the people who depend solely upon their hillside farms for food. In addition, the increasing demand for firewood for cooking and household heating has led to mass deforestation of the mountains, leaving the barren slopes more susceptible to landslide and erosion.
The difficulties of development emerged in other mountainous areas as well. Both Ladakh, and Bhutan, in the eastern Himalayas, were opened to Western tourists within the last eight years. Leh, Ladakh's tiny capital at 10,000 feet in altitude, had no hotels and no tourists in 1974. Today 10,000 tourists visit yearly and stay in dozens of hotels. Integrating these isolated and deeply traditional people with the modern world without ruining their unique culture will be difficult. ''The Ladakhis are beginning to think that to be modern, you don't work, and you travel to places to take pictures of other people working,'' said Helena Norberg Hodge, who has been working with the Ladakhis in alternative energy since 1976.
Nor are the temperate mountain ranges of the more developed world immune to difficulties. In the high altiplano of the Peruvian Andes, the people now depend upon world markets to sell their alpacas' wool. Overgrazing is the issue there. In the Piztal, a valley in Austria's Tyrol, three-quarters of the forest cover has been lost in the last 200 years, with frequent and highly destructive avalanches the result. ''We are still paying for this mistake today, and the same mistakes are still happening,'' said Bruno Messerli, a Swiss scientist and counselor to the IMS.
The ties that bind the study of mountains into a coherent science are the simple geo-ecological characteristics of the world's mountain and upland areas. High-altitude areas, with their short seasons and high climatic stress, are biologically fragile zones. Slope and gravity make them highly prone to erosion, and climatic stress makes their recovery more chancy. Upland areas comprise about a quarter of the earth's land surface, and provide the life support for about 400 million people. When the downslope effects of upland erosion are factored in - the devastating floods of India's Gangetic plain that have killed thousands and left thousands more homeless are an example - many more millions of people are affected by mountain environments.
A single event can upset the vulnerable ecological balance of an entire mountain range. After the 1815 eruption of the volcano Tamboro in Indonesia, the European Alps stayed snow-covered for two years, temporarily but decisively ruining the farmer's livelihoods there. Most of the cattle died, and families migrated to the lowlands. But in spite of the broad similarities, the serious problems in these remote and isolated areas require pinpointed solutions, IMS members agreed. Massive development programs imposed upon mountain people by outsiders and lowlanders are not the solution, they said. The variation of mountain climate and culture areas, is too great.