Green Jersey

Two years after a tundra fire

Cottongrass now blankets a swath of Alaskan land burned badly in 2007. That year, lightning struck and started what became the biggest tundra fire on record here in the north, burning an area about the size of Cape Cod for three straight months.

Yesterday, I rode in a helicopter to a a section that was severely damaged. Much of the ground is black two years later, though the white puffs of cottongrass have returned along with other green plants. Tundra, being cold and often wet, doesn’t normally burn like this — but 2007 was uncharacteristically dry and lightning struck more than 20,000 times on the North Slope (how odd is this? In the late ’80s, a year with less than 5,000 lightning strikes was normal).

With the fire, scientists gained a rare chance to study how an ecosystem reacts to this kind of event. Some of what they know: The fire decreased the amount of sunlight the ground reflects and the thaw depth, leaving long-frozen permafrost more vulnerable to melting. Melting permafrost releases carbon dioxide and methane and can send nutrients into nearby streams, affecting plant and insect life.

Warming is linked to more storms, and increased storm severity, so more fires are expected here in the years to come.

– Jennifer Weiss