Aspen trees could provide a natural buffer against wildfires, as new research shows that areas of forest where these trees dominate burn less intensely than those made of conifers. Individual aspen trees burn easily because of their thin bark, but large "stands" ‪—‬ contiguous communities of trees that are uniform in species, age and structure ‪—‬ of them are more resistant to fire than stands of conifers and can act like a firebreak. The reasons for aspen stands' resilience are not certain. She found that aspen trees were more than twice as common at the perimeters of fires than inside them, while conifers like spruce and pine were equally present in both locations. Aspen trees in Vail Colorado.