It often seems that even in very small groves of aspen, there are several hundred trees, but this is not necessarily the case. The roots of quaking aspen may spread themselves from the stem of a tree more than 60 feet. Across this distance, they often grow only slightly below the soil surface. After a fire or other aboveground disturbance it may appear that all the aspens have been killed. In fact, only the fire-sensitive aboveground stems have been damaged, the roots below remaining unharmed. Before long, thousands of sprouts will arise from previously dormant buds underground, quickly colonizing the newly opened stand.