Fire is the major ecological process on the landscape in Yukon-Charley Rivers National Preserve. Episodic large and small-scale wildland fires burn across the preserve. The preserve lies within the northern boreal forest ecological zone and a climatic region known as the interior basin. Mountains to the north and south tend to block moderating oceanic air masses, resulting in high temperatures, low precipitation and frequent lightning occurrences in the summer months. Due to these factors, fire persists as an inextricable environmental factor and has been a constant force of change for thousands of years.
Yukon-Charley Rivers National Preserve reveals a history of fire on its landscape, burned and unburned islands of vegetation -- a fire mosaic. The aspen and birch reveal recent burns while spruce indicates a lack of fire activity for 100-200 years. Without the routine occurrence of fire, organic matter accumulates, the permafrost table rises, and ecosystem productivity declines. Fire, the agent of change, removes some of the insulating organic matter, elicits a warming of the soil, maintains and rejuvenates these systems. Wildfire plays an important role in maintaining a diversity of vegetation communities that is beneficial for wildlife habitat.
The preserve encompasses over 2.5 million acres, 95% of which is managed as a Limited Management Option. This category recognizes areas where the cost of suppression may exceed the value of the resources to be protected and the exclusion of fire may be detrimental to the fire dependent ecosystem. The primary management strategies protect human life and specific resources and allow fire to contribute its natural role on the ecosystem. National Park Service, Eastern Area Fire Management staff manages these fires through routine surveillance, assessment and monitoring.
Interior Alaska is a lightning fire region. Wildfire plays an important role in maintaining a variety of habitats. Successional plant communities, which are beneficial for wildlife habitat and diversity, are induced by fire. Fire also plays a role in recycling nutrients. The successional stages that follow a fire vary, depending primarily on topography, seed source, severity of the burn, and moisture. Generally, successional stages following a fire include pioneer species such as fireweed, Labrador tea, willows and alders, followed by quaking aspen on upland, south facing slopes, paper birch on east- or west-facing slopes, and balsam poplars on the river plain. Eventually the white or black spruce association will invade and begin to dominate. The recovery rate of the boreal forest zone is relatively slow, spruce and reindeer lichen may require 100-150 years to recover. The forests within the park boundaries are not considered commercially valuable. Trees are occasionally harvested under permit for house logs, and local residents cut firewood.