How can a timber harvest improve wildlife habitat?

ArrayJune 16, 2020 at 3:12 pm

By Natural Resource Manager Jack Chappen

 Here at MDIFW's Lands Program, we are tasked with creating, maintaining, and improving wildlife habitat on the state-owned Wildlife Management Areas for the benefit of Maine’s fish and wildlife populations. One of the most effective tools we have to accomplish this is a conventional timber harvest.  It may seem contradictory in a state that is naturally almost completely forest, that cutting trees would create or improve wildlife habitat.  However, it is a common misconception that all wildlife species need old-growth forest, or even forest at all, to survive. Different animals prefer different forest and vegetative conditions to survive. You wouldn’t find American woodcock seeking shelter in a mature hemlock forest or white-tailed deer overwintering in dense shrubby fields.  Keeping habitat diversity in mind, we make sure to provide habitats as young as grassland fields, as old as mature hemlock forests, and every condition in between on our land base so as many different wildlife species can thrive as possible.

Dense, shrubby field for woodcock
Mature softwood forest for deer wintering

Much like any other living organism, forests grow and develop in distinct stages as well.  Each stage is defined by age, the type of vegetation and tree species present, and the physical structure of the forest itself.  Naturally, ecological disturbances such as wind, fire, or pest outbreaks can set a forest back to an earlier stage, or even the beginning of the forest succession cycle, depending on the severity.  However, we can’t always wait for these disturbances to occur on our land base to create the habitat we need.  Instead, we can utilize timber harvesting as a mock disturbance to set the forest back to an earlier stage or improve the habitat within a stage of forest development.

Mature aspen and birch
When mature aspen and birch is cleared it creates dense young hardwood forest ideal for grouse and woodcock

To best provide the wildlife habitat needed on the landscape, we carefully choose where to employ certain timber harvesting techniques based upon the forest conditions we find on the ground.  For example, areas with patches of mature aspen nearing the end of their lifespan, and no longer ideal ruffed grouse or woodcock habitat, would be cleared to create the dense young hardwood forest they prefer to use for protective cover.  This harvest technique is also useful in areas of mature balsam fir that are beginning to die.  Removing them releases the sapling sized trees below to become the thick softwood cover ideal for snowshoe hare and Canada lynx.

More selective harvesting techniques, like single tree selection, allow us to keep the forest in the same age stage but give more growing space to trees that we leave behind to grow bigger faster.  Selectively removing trees around ones that produce nuts, like oak and beech, increases the amount of available food for wildlife due to the larger crowns they’ll be able to grow.  A selective technique is also useful to reduce the amount of hardwood trees from softwood forests to improve winter habitat for deer.  Removing some hardwood trees allows the crowns of the remaining softwood trees to expand and close canopy gaps to prevent deep snow depths. Meanwhile, the hardwood stump will sprout new shoots, providing a winter food source.  This provides deer with safe winter cover and food in the same location, so they don’t have to expend precious energy searching for both.

Selectively removing hardwoods, like this paper birch, from softwood forests helps improve winter deer habitat.

When used thoughtfully, timber harvesting gives us the ability to create, maintain, and improve wildlife habitat in a sustainable fashion. Additionally, using a variety of different harvesting techniques will result in a diversity of different forest stages and conditions, not only within the same forest, but on our whole land base, providing habitat opportunities for all kinds of wildlife species across the state.