Ask most deer hunters about what sorts of forests and woodlots are best for white-tailed deer and many immediately will zoom in on those that produce food: oaks and other mast-producing trees.

Others, with a little better understanding of the creature's year-round needs, will talk about early successional forests -- aspen and the associated understory, where forbs and shrubs provide browse when mast isn't available.

But only a few understand the importance of conifers to deer.

In short, northern Michigan whitetails would struggle mightily without the hemlock, cedar and other conifers that help get them through the winter.

"Stands of hemlock and northern white cedar intercept snow and make travel by deer much easier," said Craig Albright, Department of Natural Resources wildlife biologist at Escanaba. "Though the harvested tops of timber species, such as sugar maple, red maple and aspen, are important food sources, the food and cover must be in close proximity."

Albright explains it another way: If the tops of harvested timber are the "kitchens" for wintering whitetails, the conifer stands are the "bedrooms."

"These complexes house deer for up to four months each year," Albright continued. "A productive wintering complex must have a balance of food and cover in a mosaic of different forest types. Removal or imbalance of either of these two components leads to reduced capability of the wintering complex to support deer."

Western Upper Peninsula Wildlife Supervisor Bob Doepker agrees.

"The absence of logging leads to decreased amounts of food available from harvested tops and also a reduction in the regeneration that deer will be able to feed upon in future winters," Doepker said. "However, the indiscriminate harvest of conifer cover leads to a loss of shelter and the decreased ability of deer to conserve energy, a loss they can ill afford during stressful winters."

Annual snow depths are relatively low in the south-central Upper Peninsula, so deer in that area are more loosely associated with conifer cover than those that "yard up" near the Lake Superior shoreline. Cedar is the predominant cover in the central and eastern U.P., but deer are strongly associated with Eastern hemlock in the northwestern U.P.

Hemlock is a slow-growing species that may take 200 to 300 years to reach maturity and can live to be 400 years old. Unfortunately, the cumulative loss of hemlock across the U.P. landscape is approximately 80 percent since pre-settlement times.

Terry McFadden, a DNR wildlife biologist in Marquette, is particularly concerned about the loss of wintering habitat along the Lake Superior shoreline in northern Marquette County.

"Stands of hemlock are perhaps the most valuable of all conifers in terms of providing shelter from snow, wind and cold temperatures," McFadden said. "The very small and dense needles intercept snow and serve as a sort of roof that creates a microclimate of warmer temperatures below the forest canopy. This protection also allows deer to move more freely, while expending less energy, as they travel to and from local food sources within wintering complexes."

The loss of conifer cover in deer wintering complexes is a major concern to Kevin Swanson, the biologist responsible for the DNR's Landowner Incentive Program in the U.P., who concentrates much of his efforts on reestablishing mesic conifer habitat on private land.

"In the mixed hardwood/hemlock stands located within yarding complexes in the northern portions of Marquette and Baraga counties, traditional management involves harvesting a portion of the hemlock during each 15-year rotation," Swanson said. "But, because sugar maple is more aggressive in becoming established after a harvest, each subsequent harvest rotation leads to a more pronounced loss of hemlock, further deteriorating the area's ability to sustain deer through the winter."

Hemlock does not regenerate as easily as sugar maple or aspen. Many of the hemlock stands that exist today were established after large-scale natural disturbances including wind events and forest fires. In most cases, hemlock seed will germinate only if the soil is thoroughly disturbed, and the low-impact logging equipment used today normally does not achieve such scarification.

The problem is intensified because deer are highly concentrated during winter months and will readily browse any seedlings that are established after a harvest.

"The situation is critical because the reduction in hemlock has resulted in deer being concentrated in fewer and smaller wintering complexes in the U.P.," said Doug Wagner, wildlife biologist at Crystal Falls. "The removal of hemlock in these areas leads to a permanent decline in snow-interception and wind-blocking values, cumulatively reducing the capability of these complexes to winter deer."

In many places, Wagner said wintering yards are in rough shape.

"There no longer is a balance," he said. "Although ample food is present in the form of hardwood regeneration and harvested tops, the complex now is capable of holding far fewer deer as a result of the removal of hemlock and other conifers."

This loss of conifer cover is a concern not only to wildlife biologists, but also to most loggers, land managers and foresters in the western U.P.

"The problem is going to be difficult to reverse due to the lack of large-scale natural disturbances and the inability of hemlock to compete with sugar maple following traditional harvest treatments in wintering complexes," Wagner said. "I'm afraid it's going to take a concerted effort by a lot of parties to reverse the trend."