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Wildfires are a natural part of ecosystems. In the cycle of life, wildfires are harbingers of destruction but also ushers of new growth. In the boreal forests and tundras of Alaska, the wildfire cycle frees up nutrients in the soil, renews the areas for the various flora to flourish and recreates new habitats for the different animals that call Alaska home.  

So, yes, wildfires do claim Alaska’s forests as it’s a natural part of life in The Last Frontier. 

Alaska Wildfire Season

The wildfire season in Alaska lasts for about two months. It typically begins in late May and lasts until late July. However, since 2006, fire managers in the state have changed the start date to April 1. The burned area varies, but it can range from a few thousand acres to several million acres. On average, wildfire in the state burns one million acres annually. 

Phases of the Alaska Wildfire Season

The International Arctic Research Center of the University of Alaska Fairbanks divides the wildfire season in Alaska into four phases. These phases are especially pronounced in the interior parts of the state and are driven by wind, drought, duff or the diurnal effect. 

Early wildfire season

The first phase is the early wildfire season, which occurs just after the snow melts in April. Dead grass and surface litter are the common fuels, and these are typically ignited by human activities, such as outdoor recreation and burning of debris. As such, these early season wildfires happen close to human communities.

Because fuel in the spring is limited, wildfire activity is mostly driven by the wind, that is, wildfires are carried across a vast expanse by the wind. However, because the ground is still moist and frozen, any wildfires that happen during this phase have low severity.

Thanks to their proximity to human communities and low severity, along with firefighters’ aggressive suppression response, early season wildfires are typically extinguished quickly. 

Peak wildfire season

The wildfire season in Alaska begins to peak around solstice. Thanks to long warm days, subsurface fuels called duff dry out. 

Duff is composed of litter, moss and lichen, which runs about a foot deep from the surface. These materials decompose slowly and become a fuel bed for wildfires that easily spread and are difficult to control. 

Because of this unique fuel condition, wildfires during this season can burn deep and linger on for days or weeks. What’s worse, the surface of the duff layer can be reignited when favorable weather comes around. This is typically in June when days are long and sunny. 

Most commonly, however, duff becomes fuel for wildfires that are ignited by lightning, which burns more acres than human-ignited fires each year. Common from mid-June to early July, these lightning-ignited duff-driven wildfires typically occur in remote locations. Often, these fires are left alone because of their role in the ecology — as long as they are not impacting any property or people.  

Drought-induced wildfire season

Droughts toward the end of July can extend and expand the wildfire season in Alaska. High temperatures and low precipitation in the late summer leave vegetation dry, which means they can be easily ignited by lightning or human activities. 

While there are fewer wildfire incidences during this season, wildfires can grow and become difficult to extinguish in extreme drought. So much so that wildfires might continue burning underground through winter. 

According to the International Arctic Research Center, while annual precipitation in the state has risen in recent years, it would still need to climb by about 7 to 10% per degree of temperature increase. This is because of the higher fire risk brought about by warming temperatures.  

Slow wildfire season

The last phase of the Alaskan wildfire season occurs during the fall. Typically, because of cooler nighttime temperatures and increasing relative humidity, wildfire incidence begins to slow down. 

However, Alaska has recorded many more warm nights, especially in the interior, today than in the early part of the 20th century. For instance, some wildfires caused by high temperatures and low precipitation have occurred in August in the past two decades. So, the risk of wildfires late in the season still looms.

Climate Change and Wildfires in Alaska

Speaking of warming temperatures, the U.S. Department of Agriculture (USDA) warns that the state could see an increase in the risk of large, frequent and severe wildfires due to climate change. 

“By 2050, burned area is projected to increase by 24 to 169% in Alaska,” the USDA states. “Changes in climate will cause longer wildfire seasons, increased fire frequency, size, and total area burned, and possibly increased wildfire severity.” This means that wildfires can start and spread more easily. 

These changes in wildfire patterns are brought about by various factors. A big contributor is the rising temperature in the Arctic, which is now twice the average global rate. From 1971 to 2017, the annual average Arctic surface air temperature climbed by 4.9°F, according to the International Arctic Research Center.

Other factors include warmer nights, drought, and a shortening snow season or earlier snow melt. In addition, Alaskan winters that have been coming later and later, changing vegetation and more frequent lightning strikes have all been contributing to the changing fire environment in the state.

In fact, Alaskans are already starting to see these effects now, with wildfire frequency and burned area having exceeded historical figures. The USDA reports that three of the four highest-acreage fire years happened since 2000. For instance, the largest wildfire in the state occurred in 2004 (Taylor Complex), and the largest tundra wildfire, the Anaktuvuk River Fire, happened just three years later in 2007. 

Does Alaska have wildfires?

In conclusion Alaska has also seen 2.5 times more acres burned from 2000 to 2020 than in the previous 20 years, states the USDA. Most of these areas are tundra and boreal forest, which are more at risk of wildfires than Alaska’s temperate rainforests that rarely experience the natural event. The state’s rainforests have also not seen an increase in the number, size or severity in the wildfires that do engulf the ecosystem.

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