A trip to a tundra fire site, but not for Tom Options

[Tom_Crumrine]

29 June 2005

Today Donie and her team are headed out to a tundra fire site that burned last summer. I couldn't go because this had been planned long before I got involved in the program and they had already filled all of the seats on the helicopter. At $800 an hour I couldn't really ask them to make another flight just for me. I did go to the helicopter safety briefing and watch them all take off.

But don't feel bad for me dear reader, I have plenty of helicopter riding experience. The highlight of it was a 1992 aerial survey of Dollywood while on spring break in college. We soared high above Dollywood and Pigeon Forge, Tennessee. It was memorable for many reasons.


A common view of a non-tundra fire. This is the type of fire that filled Fairbanks with smoke for a good part of last summer.

Tundra Fires

Fires in Alaska are common, usually started by lightning, but tundra fires are very rare. The tundra is mainly small plants and much of it is very wet so even a lightning strike is not usually enough to ignite a fire. Last summer on June 13th Donie and her husband Peter were hiking Slope Mountain and a storm system moved in. They noticed plenty of lightning and on their way down thought that they saw some smoke close by. Returning to Toolik Camp they discovered that indeed a tundra fire had begun. The fire burned from June 13-June 15 and covered about 136 hectares. With the help of VECO Polar resources a group of 12 scientists was able to get some helicopter time and was able to sampe the site on July 2 and on August 15 of 2004.


Flying out to the site on the helicopter.

During those sampling trips the researchers looked at species characteristics, vegetation characteristics and soil characteristics. They divided the burn sight into transects of light burn, heavy burn and no burn and looked at the previously mentioned characteristics.


Heat killed betula nana (normally green leaves). This wasn't charred it was killed by the heat.

They came to the following conclusions:

1. tundra plants are better adapted to burning than they had hypothesized. since tundra fires are rare it was not expected that the plants would be pre-adapted to fire.
2. Soil moisture is higher in the burned areas possibly due to reduced transpiration in the site.
3. 2 months after the burn the plants were greener and the depth of thaw was larger than in control areas.

What does this possibly mean? Well, let's for a moment combine some of Donie et. al's. other work with the ideas about fires. If Betula begins to grow more as temperatures increase then there is much more fuel for fires. If temperatures are warmer then things will be more dry. If there is more fuel then when lightning strikes fires could more easily get going and could become more frequent.

A big concern that the scientist have is whether the permafrost will recover. A lot is known about permafrost but much about it remains a mystery. In 1977 a fire on the Seward Peninsula burned an area that had been previously surveyed in 1973. This set up a situation where pre-fire conditions were known and was ideal for studying the long term effects of a tundra fire. Charles Racine et. al. recently published their findings on 24 years of research at the site. They found that willows had grown much larger than pre-fire, that no moss or lichen recovery had occurred and that the permafrost depth is much greater or gone completely. Their conclusion,

"These changes in tundra vegetaion and permafrost following fire suggest that such fires could accelerate the predicted effects of climate warming on ecosystems in the Arctic." (Racine et. al. 2004)

Donie and her team will be looking at many of the same types of things as they continue to study this fire site. I hope to have more information for you tomorrow and maybe some pictures. My thanks go out to Donie Bret-Harte and Gus Shaver for helping explain this work for me, and to the scientists from the survey team from last year.