Spruce-Fir Forest
The 2015 North Carolina Wildlife Action Plan defines 41 priority habitats for the state. More information about this habitat can be found in Section 4.4.2.
Contents
Habitat Priorities
Surveys
- Determine the distribution, relative abundance, and status of all wildlife species associated with spruce–fir forests. (Surveys Priority)
- Focus survey priorities on species believed to be declining, at risk, or exclusively dependent on spruce–fir forest communities (e.g., the Red Crossbill, Brown Creeper, Black-capped Chickadee, Rock Vole, Rock Shrew, Carolina Northern Flying Squirrel, Weller's Salamander, Northern and Southern Pigmy Salamanders, etc.). (Surveys Priority)
- Collect baseline microhabitat and microclimate characteristics in spruce–fir salamander communities. (Surveys Priority)
Monitoring
- Expand and/or target monitoring systems to assess current population status and trend information for all wildlife species associated with spruce–fir forests.
- Establish mechanisms for monitoring the distribution and condition of spruce–fir habitats over time.
- Monitor phenology of priority species and spruce–fir communities in relation to climate change.
- Monitor microhabitat and microclimate characteristics in spruce–fir salamander communities in relation to climate change.
Research
- Conduct studies to explore the degree of endemism of southern Appalachian populations (e.g., Pine Siskins, Red Crossbills, Northern Saw-whet Owls, Black-capped Chickadees, etc.).
- Conduct studies to explore the degree of genetic isolation of species restricted to high elevations (e.g., Carolina Northern Flying Squirrels, Rock Voles, Rock Shrews, Weller's Salamanders, Northern Saw-whet Owls, etc.).
- Conduct research on population demographics including trends, population structure, survivorship, reproduction, and population viability for all spruce–fir associated species/groups.
- Species phenology needs to be investigated, especially where there are endemic populations.
Management Practices
- Develop and/or implement techniques for managing pure spruce stands to include habitat components of the entire spruce–fir/northern hardwood community (i.e., thinning).
- Test silvicultural techniques to reintroduce spruce into formerly disturbed areas that have regenerated in northern hardwood or Northern Red Oak communities (i.e., thinning and underplanting).
- Protect spruce–fir communities from wildfire, as this is an important action that can be taken to save the remnants of these communities.
Conservation Programs and Partnerships
Description
Red Spruce−Fraser Fir forests are considered an endangered community in North Carolina and are ranked the second most endangered ecosystem in the United States (White et al. 2012; Noss et al. 1995, Christensen NL et al. 1996; Rentch et al. 2007). These forests are dominated by Red Spruce and Fraser Fir and occur on the high mountain tops in western North Carolina, generally over 5,500 feet in elevation. The cold climate of the high elevations is equivalent in some ways to the boreal forests of Canada. However, the climate differs from the north in that it is less continuously cold and much wetter, with both rain and fog tending to concentrate on the mountain tops.
Spruce−fir forests are divided into two natural community types: Fraser Fir forest and Red Spruce−Fraser Fir forest, each with several variants (Schafale 2012). Both communities tend to have dense canopies under natural conditions. A variety of distinctive shrubs and herbs, many of them more common in the northern United States, but some endemic to the southern Appalachians, occur beneath the canopy. Lush beds of moss and ferns cover the rocky soil and abundant fallen logs in some areas.
- Fraser Fir forests occur on the highest mountain tops, where the Fraser Fir is the only tree species able to survive the cold, wind, ice, and storms in large numbers. Most Fraser Fir forests now exist as patches of dense young trees due to infestations of Balsam Wooly Adelgid, an introduced insect pest that kills adult Fraser Firs.
- Red Spruce−Fraser Fir forests occur in slightly less hostile environments where Red Spruce and Yellow Birch can also persist in large numbers. Red Spruce−Fraser Fir forests have canopies of remnant spruce trees, many of which are also dying. The least affected sites are the lowest elevation examples, which have relatively little fir.
Estimates of the amount of spruce–fir habitat are quite variable depending upon a number of factors including the estimation methods and habitat definition. The Partners in Flight Bird Conservation Plan for the Southern Blue Ridge (Hunter et al. 1999) identifies over 66,000 acres of spruce−fir forest in the southern Blue Ridge physiographic province and the Southern Appalachian Assessment (SAMAB 1996) identifies over 75,000 acres in North Carolina and Tennessee. The vast majority of these areas occur in North Carolina.
The 2005 WAP described Southern Blue Ridge Mountain spruce–fir forests as a priority habitat (see Chapter 5) (NCWRC 2005).
Location of Habitat
Spruce−fir habitats in North Carolina are now found within a narrow range of suitable conditions, isolated from each other and the rest of their range. There are currently six significant areas of spruce−fir habitats in western North Carolina, including portions of Grandfather Mountain, Roan Mountain, the Black/Craggy Mountains, the Great Balsam Mountains, the Plott Balsam Mountains, and the Great Smoky Mountains.
Most of the spruce−fir habitat in North Carolina is located on public land, or private lands with permanent conservation easements, with estimates of 90%–95% in conservation ownership in the southern Blue Ridge physiographic province including North Carolina, Tennessee, and Virginia (Hunter et al. 1999; SAMAB 1996). However, significant private ownership of spruce−fir habitat occurs in the Plott Balsams and Black/Craggy Mountains, and to lesser extents in several other ranges.
Red Spruce habitats of lesser size or with somewhat different ecological community associates occur in a few other locations, including Long Hope Valley, Beech Mountain, Unaka Mountain, Unicoi Mountains, and Alarka Laurel.
Problems Affecting Habitats
Given the high number of endemic and disjunct species that use the spruce−fir habitat, it is the one community where threats to biodiversity are the greatest. Much of the spruce−fir habitat in North Carolina and throughout the southern Appalachians has been significantly altered due to a number of factors including historic logging, fire, exotic insects, historic grazing, and recreational development. Much of the spruce was logged in the early 20th century and in some areas (notably the Great Balsams) slash fires burned not only the coarse woody debris, but also the organic soil, which has subsequently inhibited the redevelopment of spruce and fir forests over large areas (Schafale and Weakley 1990).
The removal of mature Fraser Fir from the canopy has profound implications for the spruce–fir ecosystem and the continued existence of several unique plants and animals (Nicholas et al. 1999). Following extensive logging during the last century, it is estimated that as much as 50% of all Appalachian spruce−fir forests were replaced through successional growth of hardwood species (White et al. 2012; Pyle 1984). Several of the species face outright extinction and others, if lost, are unlikely to ever recover within the region.
The Blue Ridge Parkway was completed through western North Carolina during the latter part of the 20th century. The Parkway traverses most of the high-elevation islands of spruce−fir habitat. The Parkway and its associated development (the motor road, vistas, and visitor facilities) have contributed to fragmentation and had a significant impact on the amount of spruce−fir habitat available.
In the latter part of the 20th century, the Balsam Wooly Adelgid (Adelges piceae) began to have severe negative impacts on Fraser Firs throughout the region, resulting in the death of most of the mature fir of the high-elevation forests (White et al. 2012). Recent negative impacts include insect outbreaks in several areas including Roan Mountain, the Black Mountains, and the Great Balsam Mountains.
Some research has shown that recent increases in acid precipitation in the Mountains of western North Carolina may have impacts on forest health and productivity, particularly in the high Mountains (Schafale and Weakley 1990; Hunter et al. 1999). While some Fraser Firs remain in certain locations, the majority of late successional fir has been killed and often replaced by young fir, mixed northern hardwoods, and open, herbaceous habitats.
Climate Change Compared to Other Threats
Comparing climate change to other ecosystem threats can help define shortand long-term conservation actions and recommendations. Balsam Woolly Adelgid, air pollution, and climate change are all major threats; however, this habitat is among the most vulnerable to climate change.
Many species are currently excluded from these high-elevation communities because of the extreme climate, with winter cold the most likely cause. Mild winters presumably will lead to invasion by species from lower elevations. This will eventually lead to competitive exclusion of distinctive spruce−fir species from the lower parts of their elevational range (DeWan et al. 2010). The fact that these habitats are so small and isolated from each other could have a negative impact upon genetic health of individual populations, as well as demographic effects upon populations.
Impacts to Wildlife
Spruce−fir provides critical habitat for numerous plant and animal species found nowhere else in North Carolina. Twenty species or subspecies of invertebrates are endemic to spruce−fir forests in the southern Appalachians. Another nine are highly disjunct within this region, with their next nearest populations located in New England or Canada (some may turn out to be distinct species once genetic studies are done). Still more such species exist within other insect orders and in other invertebrate taxa such as myriapods, Tardigrades, and land snails. For terrestrial animals, this level of endemism/disjunction is unmatched by any other habitat group in the state.
Carolina Northern Flying Squirrel, a federal listed endangered subspecies, forages on conifers and fungi found in high-elevation spruce−fir and hardwood forests. The moist, boreal conditions support the mycorrhizal fungi that grow in association with the tree roots. Habitat destruction and fragmentation from development, as well as alteration from logging, mineral extraction, pollution, and pest species, has reduced available habitat for the Carolina Northern Flying Squirrel. The highest quality habitat for the squirrel is the transition zone between spruce–fir forest and the northern hardwood forest, a mix of Red Spruce, Fraser Fir, Yellow Birch, Buckeye, Sugar Maple, and even some beech at elevations above 4,000 feet. Information about Carolina Northern Flying Squirrel can be found in Chapter 3.7 of this document.
Spruce–fir communities provide critical breeding habitat for many landbirds of conservation concern according to Partners in Flight (Brown Creeper, Northern Saw-whet Owl, Black-capped Chickadee) that are likely endemic to these high peaks (Pashley et al. 2000; Rich et al. 2004; Johns 2004). Local relative abundance of many birds and mammals (e.g., the Red Crossbill, Brown Creeper, Pine Siskin, Black-capped Chickadee, Northern Saw-whet Owl, Northern Flying Squirrel) has decreased as the availability of spruce–fir habitats has declined. The fact that these habitats are so small and isolated from each other could have a negative impact upon genetic health of individual populations, as well as demographic effects upon populations.
Many species using spruce–fir forests are flightless, including salamanders and eight species of ground beetles (Trechus sp.). Weller’s Salamander is at the highest risk of being pushed off the top of the mountain because of climate change. As is generally true for “sky island” species, even those capable of flight (or ballooning in the possible case of the Spruce–fir Moss Spider), they rarely disperse out of their habitat, if at all.
All of these species depend on cool, moist microclimates, but the Spruce–fir Moss Spider, ground beetles, and salamanders are particularly susceptible to desiccation and are among the species most likely to be affected by climate change of any in the state.