Fire Suppression in Central Oregon and the Expansion of the Western juniper

I grew up in Bend, Oregon and have always been associated with the rangelands of the High Desert. Central Oregon has a diversity of ecotypes, such as sagebrush steppe, grasslands, juniper woodlands, Ponderosa/Lodgepole Pine forests, and the higher elevation coniferous forests. All of these ecosystems have evolved with and adapted to fire, especially the Pine forests. However, most of my experiences have been in the Juniper woodlands and sagebrush steppe. The history of the expansion of the Western Juniper (Juniperus occidentalis) throughout central Oregon is of much interest to me. Fire suppression became quite common as the West was settled. It was feared by settlers and thus had to be controlled. Juniper is very adaptive to the drought conditions of the high desert with its long taproot and extensive lateral root system. However, juniper is not resistant to fire. Historically, the western juniper was only found in the higher elevation rocky outcroppings, where it could escape the impacts of fire. As wildfires were controlled across the western U.S., the distribution of juniper trees increased rapidly. They encroached into sagebrush steppe and grasslands communities, outcompeting for resources. The western juniper is so competitive, vast oceans of sagebrush were eventually converted to juniper woodlands. Thick stands of juniper can now be found throughout central Oregon, creating fire hazards. Changed fire regimes have changed the vegetation composition of the high desert, and where historic fire were more common but with less intensity, current wild fires are typically less common but with high intensity, further changing plant communities and disturbance regimes.

The Keystone Ranch is located outside of Prineville, Oregon, approximately 45 miles east of Bend, Oregon. This image illustrates the magnitude of western juniper expansion due to fire suppression. http://www.conifers.org/cu/Juniperus_occidentalis_occidentalis.php