Public lands are facing new problems as a result of the changing population and economic dynamics in the four corner states, according to a report.

The report, released Thursday by the Washington-based Wilderness Society, said the growth of Arizona, Colorado, New Mexico and Utah "pose new tests for the millions of acres of ecological treasures found on public lands throughout the region, much of it still at risk from commodity development."The report said while the region's population increased 19 percent between 1980 and 1988, the contribution of natural resource industries declined.

It said newcomers to the area face conflicts with environmental concerns and oldline mining and ranching interests.

"Demands for water, land and energy by a larger, increasingly urbanized population threaten the very quality of life that attracts newcomers in the first place," said Thomas Goerold, the Denver-based author of the report.

The report also said declining commodity prices and the growth of service sector industries are among the factors that have contributed to the region's decreasing dependence on commodity production as a key element in the economy.