Fire in Ecosystems: Arctic Tundra

Tussock cottongrass flowering in Noatak National Preserve one year after fire.

NPS/J BARNES

Distribution and General Characteristics

Arctic tundra plants and shrubs live across northern and far western areas in Alaska. Forests typically do not grow well in these areas. Hiking in the tundra can feel like walking on a sponge between large, grassy bowling balls - tussocks. Tussock-forming sedges, like cottongrass and Bigleow’s sedge grow mixed with low-growing shrubs like willow and dwarf birch. Mosses and lichens cover the ground and form a deep organic mat, or duff, made of decomposing plant material. This protects the soil and permafrost below.

: Historic fires from 1940 through2020 located within the arctic and subarctic tundra of Alaska.

NPS/J HROBAK

Historic Role of Fire

Fires in the tundra happen less often than in the boreal forest. Fires can be sporadic and widely distributed. The years between fire events, called fire return intervals, vary widely from 30 years to over 1,000 years in the tundra. In the past, fires have burned more frequently on the Seward Peninsula and in the Noatak Valley than in other tundra regions. This is due to slightly warmer and drier conditions and higher amounts of plants and shrubs above ground such as tussock cottongrass.

Tussock cottongrass (Eriophorum vaginatum) burns easily yet is very hardy. It grows quickly and is very productive, forming a tussock made of fine dead fuels from the previous year. These fine fuels burn quickly and easily. Tundra fires are usually wind driven and move rapidly, burning through years of accumulated tussock grass thatch. The tussock growth protects the cottongrass roots and plant tissues from fire. These plants and shrubs recover and grow vigorously after fire, benefitting from nutrients and warmer soils after a fire.

Left image
Tussocks resprout very quickly after fire. This vegetation plot shows plant recovery only one month after a fire in 1982.
Credit: NPS/C RACINE

Right image
: The same vegetation plot burned again in 2012. Notice how much larger and greener the tussocks are one year after the second fire (2013). Fires can stimulate tussock growth and increase plant productivity.
Credit: NPS/J BARNES

Current State and Management Actions

There are over 143 million acres of arctic & subarctic tundra in Alaska, most of which is designated in a Limited Fire Management Option. In these areas, fires function in their natural ecological role. The number of fires that start in tundra are limited by the source of ignitions (like lightning), moisture conditions, and the amount of burnable vegetation present... Scientists have observed warmer temperatures and an increase in fire activity over the past twenty years in tundra where fires were previously less common.

Climate model forecasts show more warming in the future, particularly in the high northern areas. This could affect the length of the growing season, how well plants and shrubs grow, and rain and snowfall. With this, scientists expect to see more fires. How this will impact the arctic tundra ecosystem is still unknown.

Scientists observe plant life and fire over time to learn about changes happening in the national parks. National Park Service fire managers use this information to make decisions. Their goal is to protect resources and help ecosystems stay in balance.

Links for further reading

• The Burning Tundra: A Look Back at the last 6,000 Years of Fire in the Noatak National Preserve, Northwestern Alaska
• Long-term Monitoring of Vegetation Change Following Tundra Fires in Noatak National Preserve, Alaska