Controlled burn considered to increase moose forage

State game managers hope to conduct a 6,000-acre "research burn" about 70 miles south of Fairbanks in Game Management Unit 20A sometime in the next month.

Three burn units of about 2,000 acres each have been selected in the West Fork of the Little Delta River.

Moose congregate in the Alaska Range foothills during the winter months and the growing number of moose in unit 20A have taken a toll on the forage. It has caused nutritional stress in moose, especially cows, said Fairbanks area biologist Don Young.

"We don't think the summer range is limiting the population in 20A at all -- it's winter range," he said. "What we really need in 20A is provide more or higher quality winter range."

Natural fires do not usually start in the foothills, Young said.

"If we can get a fire to carry in there we feel we can improve the range," he said.

It's a new strategy the department hatched after watching a proposed burn for 75,000 acres of winter range in the western Tanana Flats sit on the books for 15 years because of poor weather or a lack of available firefighters to keep the blaze within bounds.

The window for the research burn is May 15 to June 15.

"It's a whole different approach," Young said. "We never explored burning in the foothills and then we got to thinking if we can't pull off these big burns on the flats because they put up a lot of smoke, maybe a better alternative would be small-scale fire in the southern foothills that will put up less smoke coming into Fairbanks and still improve winter range for moose."

Unit 20A is designated as an intensive management area because of its high moose harvest by hunters. It has one of the highest moose densities in the state with about 12,500 moose over 5,000 square miles.

Last year, the reported harvest was 850 moose. The average harvest during the past five years is more than 1,000 moose per year.

However, cows are having their first calves at an older age. They are producing smaller calves and giving birth to fewer twins, all signs that they are nutritionally challenged, Young said.

The burn plan calls for firefighters from the state Division of Forestry to drop fire-starting incendiary balls from a helicopter to ignite and burn only the above-ground portions of browse, such as dead grass, leaves and twigs, which will stimulate new sprouting from the root system.

The burns are similar to prescribed burns the department has done in the Nenana Ruffed Grouse Enhancement Project on Nenana Ridge.

The two agencies conducted a one-acre test burn in the same area last year to see how vegetation would respond.

"By fall there were willows that had sprouted and were grown up to a height that would be utilized by moose that winter," said Tom Paragi, intensive management coordinator for the Department of Fish and Game in Fairbanks.

The burn areas are predominantly willow shrubs with some birch and aspen trees. The burns will be focused in small creek drainages where moose forage is concentrated, Paragi said.

Biologists conducted browse surveys in March to quantify how much browse was being produced and how much was being removed by moose so they can track the results of the burns.

"We want to document if there's an increase in the amount of browse produced and the degree to which moose are utilizing it," Paragi said. "We're hoping if we burn this by late May, then by September there could be some browse as high as 3 feet up there if we get growth like we did at lower elevations."

Browse must be at least 18 inches high for moose to use it, he said.