Refuge Notebook

Article

July 17, 2009

Shantatalik Creek fire bodes well for wildlife
By Ed Berg

It’s fire time once again on the Kenai. There is smoke in the air and the sound of whirring helicopters. The Shantatalik Creek fire has burned approximately 14,000 acres since starting from a lightning strike on June 29th.

Fire is a vital part of the forest cycle on the Kenai. Spruce bark beetles are the primary disturbance agent in the upland white spruce forests, and fire is the most effective way to prepare a seedbed for restarting the forest cycle after a period of heavy beetle kill, such as we experienced in the 1990s.

Our fire history studies indicate that the area north of Tustumena Lake, including Shantatalik Creek, burned in the 1870s. Trapper Andrew Berg, who lived on Tustumena Lake from 1891 until his death in 1939 believed that there had been burns in 1871, 1891 and a partial re-burn in 1910. He reported that the 1910 re-burn removed much of the dead and down wood from the previous burns and made the country easily accessible to moose. These fires produced abundant willow browse and ultimately attracted international hunters seeking the “Giant Kenai Moose” in the period of 1898 through the 1920s.

We know the spruce bark beetles hit the area lightly in the 1970s and then heavily starting in 1992.

The present fire is a mid-season fire during a dry summer, so there will likely be good consumption of the organic layer and bare mineral soil will be exposed, at least in patches. There is plenty of down spruce on the ground that could burn for days, further consuming the organic layer.

Bare mineral soil provides the best seedbed for seed germination and seedling establishment. We like to see fires that are rated “severe” in terms of their fuel consumption, because these fires quickly promote new hardwood browse for moose and hares, as well as providing a nursery for spruce seedlings, which grow more slowly than hardwoods like birch, aspen, cottonwood, and willow.

The most productive areas for wildlife on the Refuge are the areas that have been most severely burned. The large (79,000 acre) 1969 Swanson River Burn northwest of Sterling, for example, re-grew with profuse birch browse and has been a favorite moose hunting area since the 1970s. By now however much of the birch has grown too tall to be browsed effectively by moose and certainly by hares.

Currently, the 1987 prescribed burn in Skilak Loop and the 1994 Windy Point burn on the southwest end of Tustumena Lake are severe burn areas that have dense “dog hair” birch regeneration and abundant moose herds in the winter. The somewhat older 1974 Pipeline Road burn in the Mystery Creek – Chickaloon River area is a similar young birch forest on a severe burn with abundant winter moose.

On the opposite end of the burn severity scale, we have the early season grass-fed fires which typically kill the trees but don’t consume the organic mat because it is too wet or frozen. The 1994 Crooked Creek burn southwest of Tustumena Lake, for example, occurred in early June and had mineral soil exposure of only 1-2%. Much of the burn regenerated as thick bluejoint (Calamagrostis) grass, some of which torched in the June 2007 Caribou Hills fire east of Ninilchik, another early season burn with poor mineral soil exposure. These flashy early season fires are basically an ecological waste, because they produce little browse for the moose and hares, little spruce regeneration, and lots of grass for future early season fires.

Early season grass fires are typically a legacy of logging, because removal of the trees opens up the ground to sunlight. Bluejoint grass is usually always present on the forest floor, but in small amounts above ground, whereas its rhizomes (underground stems) are everywhere, and generate new above-ground shoots as soon as sunlight arrives.

Bluejoint grass is slow to establish from seeds on bare mineral soil, so it can’t out-compete birch and other hardwoods after a severe mineral soil exposing fire. Logging however doesn’t disturb the rhizomes, so bluejoint grass soon converts logged areas into grassy savannas. The sunlit grass forms a dense sod which lowers soil temperatures and inhibits seedling germination.

Before European settlement there were probably no grassy savannas on the Kenai. Grass is always a minor component in our pollen profiles from lake sediment cores, which record as much as 13,000 years of postglacial vegetation history. The dense white/Lutz spruce forests of the southern Kenai burned only every 400 to 600 years, according to our fire history studies. On average, the mixed spruce and hardwood forests of the central Kenai burned every 130 years, whereas spruce bark beetles thinned these stands every 50 years. White/Lutz and Sitka spruce in the pre-Settlement era regenerated mostly on rotten nurse logs, as shown by the stilted roots of older trees. When these species germinate on mineral soil they extend their roots straight out, perpendicular to the trunk, as can be seen in the many post-Settlement burn areas on the Kenai.

With land clearing and logging, bluejoint grass has flourished, so we now have grassy savannas and flashy grass fires as another expression of the human footprint on the landscape.

The Shantatalik Creek fire is, blessedly, an example of the older style of pre-Settlement fire, unsupported by grassy savannas. It will likely create a mosaic pattern, consisting of hardwoods in the more severely burned patches, spruce in the more lightly burned areas, with some muskeg pockets remaining more or less unchanged in the wet areas.

The fire is burning in an area classified as “Wilderness” and “Limited” fire suppression. Firefighters have successfully used direct attack on the western and northwestern flanks to limit the possibility of the fire moving off the Refuge toward human habitation. If the fire burns east to Benchlands and/or south to Tustumena Lake, we would welcome this as an opportunity to rejuvenate a lot of beetle-killed forest which would reduce the risk of a future, more dangerous fire under drier and windier conditions.

You can see photos and videos of the fire on our website http://kenai.fws.gov/ (click on Shanta Creek Fire Updates).

Ed Berg has been the ecologist at the Kenai National Wildlife Refuge since 1993. Ed will be teaching his 5-week 1-credit “Geology of Kachemak Bay” course at the Kenai Peninsula College in Soldotna and Homer, beginning Sept 8 and 10, respectively. You can check on new bird arrivals or report your bird sighting on the Kenai National Wildlife Refuge Birding Hotline (907) 262-2300.