Slower-growing trees, dying trees, forest fires, insect infestation, and big changes in where various tree species are dominant are part of a forecast being suggested for southwestern U.S. forests. That's if temperature and aridity rise as predicted by the U.S. Geological Survey and other federal researchers.

Southwestern forests, they say, may experience all of these changes since they are particularly sensitive to warmer temperatures and increased dryness. They report mountain forests across the Southwest are already experiencing forest die-offs and rapid shifts in the types of trees that live there.

From watershed protection and timber supplies to recreation, the researchers warn that such changes in Southwest forest vegetation could have significant effects on a wide range of goods and services.