Biologists and Foresters Come Together to Manage Carolina Northern Flying Squirrel Habitat

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There’s a fungus that grows amidst the roots of high-elevation conifer trees – largely red spruce and Fraser fir - in the southern Appalachians. This fungus is a primary food for endangered Carolina northern flying squirrels. The problem is, these conifer trees have taken a beating – from unsustainable, industrial logging and subsequent wildfire a hundred years ago, to acid precipitation, to the arrival of the balsam woolly adelgid, an invasive insect that kills Fraser fir trees. Fewer conifer trees, less fungus. Less fungus, fewer Carolina northern flying squirrels.

The Southern Appalachian Spruce Restoration Initiative, which includes the Service, is working to restore red spruce to these areas – via planting nursery-raised trees, and knocking-back competition to existing spruce so they may grow into cone-bearing trees. However, controlling that competition requires a gentle touch – while red spruce supports the food the squirrels need, the yellow birch that can compete with spruce for nutrients, water, and sunlight, often provides shelter to the squirrels.

A team of wildlife biologists and foresters from the Service, Appalachian Trail Conservancy, Forest Stewards Guild, N.C. State Parks, N.C. Wildlife Resources Commission, and U.S. Forest Service recently visited a site in North Carolina’s Black Mountains to develop an understanding of how best to release existing red spruce from competition, while ensuring there are still plenty of large yellow birch that are valuable to the squirrel.

A team working to restore red spruce in North Carolina's Black Mountains gather before heading into the backcountry.
Service biologist Sue Cameron and Joe Franklin, N.C. Wildlife Resources Commission forester, head into the backcountry of North Carolina's Black Mountains.
Before beginning work, biologists and foresters open digital maps on their phones and talk through where they'll be working.
Joe Franklin, forester with the N.C. Wildlife Resources Commission, provides input on how best to release red spruce trees so they can grow into the forest canopy, while ensuring sufficient yellow birch for imperiled Carolina northern flying squirrels, which use them as nesting trees.
Service biologist Sue Cameron (L) and N.C. Wildlife Resources Commission biologist Chris Kelly examine the canopy of a high-elevation southern Appalachian forest, considering which trees are receiving most of the sunlight, and while trees are getting shaded.
Biologists and foresters come together in North Carolina's Black Mountains to discuss how best to release red spruce trees, while leaving yellow birch trees that may be important for the Carolina northern flying squirrel.
Forester Shawn Swarts measures the diameter of a spruce tree targeted for release. Once competing trees are killed, the expectation is this tree will use the additional food, water, and light to grow larger.