Aspen and Succession
July 31, 2009
The photo above shows a clump of aspens sheltering a lone conifer tree near Steamboat Springs, Colorado. Moreover, it demonstrates an interesting ecological succession taking place between North American Aspen (Populus tremuloides) and conifers. Aspen are widely distributed across the U.S., and are especially notable in the West, where their brilliant fall colors are a popular tourist draw. They grow in stands of identical clones, each tree growing from an underground root system that originated from a single seedling. Individual trees may live 40-150 years, while the underground root system may actually persist for thousands of years. Aspen are not shade tolerant. Conversely, many young conifers thrive in the shade provided by a grove of aspen. As the conifers grow, they may eventually crowd out and shade the aspens that provided protection to them in their younger years. Aspen are important in other ways as well, having highly nutritious bark used by many herbivores such as beaver and elk. Photo taken on July 31, 2004.