by Jess Riddle : Forest Ecologist
If you want to see a classic Southern Appalachian spring wildflower display, the rich soils on the north side of Duncan Ridge support large populations of spring ephemerals and several rare species. If you want to catch Georgia trout, Cooper Creek is one of the state’s largest trout streams and the tributaries support native brook trout. If you want to go on a multi-day backpacking trip, the Duncan Ridge Trail offers a quiet alternative to the Appalachian Trail.
In May 2014, the Blue Ridge Ranger District proposed a prescribed burning and silviculture project that will impact all of these areas. That initial scoping for the project, located between Blairsville and Suches, generated 585 public comments. Since then, Georgia ForestWatch staff and volunteer District Leaders have visited dozens of stands in the project area, and recently met with the Forest Service, Southern Environmental Law Center (SELC), and the Sierra Club to hear about possible changes to the project and discuss in the field potentially problematic treatments.
The Forest Service states that the goals of the Cooper Creek Watershed Project are “to: (1) restore native plant communities, (2) enhance wildlife habitat conditions, and (3) improve forest health.” The scoping notice also lists several more specific forest plan goals that the project would ideally contribute to, such as “reduce stem density on 5,500 acres” of oak and oak-pine forest and create “canopy gaps within closed-canopied mid- and late-successional mesic deciduous forest” on 10,800 acres. To achieve those goals, the Forest Service has proposed supplementing existing prescribed burning with a wide variety of silvicultural treatments that fall into two general classes: commercial treatments, which remove cut trees from the site; and non-commercial treatments, which leave the cut trees. Commercial treatments in the project include regeneration harvests and various forms of thinning. Noncommercial treatments include midstory removal, release treatments, and the cut and leave versions of woodland thinning and canopy gap creation.
As planned in the most recent version of this still evolving project, woodland treatments make up the single largest proportion of the project at 764 acres, with over 500 of those acres in commercial treatments. All of the woodland thinning is planned on the Cooper Creek side of the project. Woodlands provide unique habitat where individual and clumps of trees have large, open, sunny areas between them. They naturally occur in areas where the balance between growth, related to soil fertility, and disturbance, such as fire, is such that trees have difficulty establishing and growing to maturity. In this region, moist sites support high rates of growth and have relatively few disturbances that affect seedlings and saplings. Hence, moist sites support forest, but questions remain around how many and which dry sites would naturally support woodland rather than forest. The Forest Service has presented these treatments as “restoration,” indicating they believe these stands were once woodlands. Restoration inherently includes the idea of a reference condition, which provides both a goal for restoration and a means for evaluating restoration success. The lack of good reference conditions complicates restoration of dry sites in the mountains. The Southern Appalachians have gone through periods of both fire suppression and European burning. Consequently, we do not have sites today that show what dry sites would look like under a natural fire regime, and early European fire use influences much of our historical information. Due to the generally fertile soils and high precipitation this region receives, we believe that woodland is naturally scarce in the region and that many fairly dry sites would naturally be forest.
Pine/pine-oak thinning makes up nearly as much of the project, 740 acres. Like woodland thinning, pine thinning is heavily concentrated in the Cooper Creek watershed part of the project area, and is often directly downslope of the woodland thinnings. The Forest Service suggests white pine, the only pine of any abundance in the project area, is “off-site” and removing it will improve forest health. White pine can tolerate a wide variety of soil moisture levels, but fire easily kills saplings. Industrial logging of the early 20th century produced high-light environments that the extremely fast growing species could take advantage of, and the Forest Service experimented with white pine plantations in the area. Hence, those factors have likely allowed white pine to increase in abundance in the Cooper Creek area over the past 100 years, particularly on drier sites. However, white pine was a component of pre-settlement forests, and moist, well-drained areas in the Cooper Creek watershed provide excellent white pine habitat. The Forest Service will also target tuliptree and red maple for removal using a similar rationale, though the same caveats apply.
Regeneration harvests on average remove 80 to 90% of the canopy to produce habitat for wildlife that benefit from very young forest. The roughly 250 acres proposed for this treatment include both stands that the Forest Service clearcut in recent decades and stands that have not been cut since the era of broad-scale industrial logging.
Many wildlife species make use of the areas where the fall of one or a few trees produces a patch of higher light and rampant growth of plants that require high light conditions. The commercial canopy gap thinning aims to artificially produce habitat for those wildlife species by combining a general thinning, where roughly every other canopy tree would be removed, with half-acre clearcuts (i.e. gaps). Natural canopy disturbances such as wind storms differ from this treatment in that they typically produce smaller gaps within an otherwise closed canopy, and fallen trees are left as a resource for fungi, insects, and animals that feed on them. The non-commercial canopy gap treatment more closely resembles natural disturbance because cut trees will be left and no thinning will occur outside the canopy gaps. However, those gaps will be relatively large, about half an acre.
Finally, the release and midstory treatments differ from the other treatments in that they will not cut mature overstory trees. The release treatment focuses on stands that were clearcut within the last few decades and tries to increase the proportion of oak in the future stand by cutting other species currently surrounding young oaks in the canopy. The midstory treatment also tries to increase oak regeneration, but does so by focusing on oak seedlings and saplings in the understory of mature forests. This treatment removes competing trees growing below the main level of the canopy, which can provide enough light to increase growth and survival of oak seedlings and saplings but not so much light that tuliptree starts regenerating. The scoping notice implies the midstory treatment is intended to prepare for future “stand regeneration.”
We have recently learned of changes to the project that the Forest Service is considering in response to public scoping comments. These changes would address some of our concerns by dropping almost all treatments on the rich upper slopes on Duncan Ridge’s north side. That change will help protect most of the rare species in the area, protect the most diverse forests in the project, and drastically reduce soil erosion. Potential changes would also shift the regeneration harvests away from mature stands on the most fertile sites, stands of high biological value.
While these changes are a welcome improvement, the project could still result in significant ecological damage. A few of the most mature and rich stands are targeted for non-commercial canopy gap treatment. That treatment is not as damaging as regeneration harvests, but we believe healthy stands with significant wildlife value are not appropriate sites for silvicultural management. Instead, canopy gap treatments should target uniform stands with little structural diversity (i.e. little variety in tree size and few gaps), such as old-field tuliptree stands.
The overall shift in the location of regeneration stands is also an improvement, but some newly proposed regeneration harvests target mature forests, primarily oak stands. Regeneration harvests can be implemented immediately in literally any forest, but only long periods of time can produce mature forests. More appropriate stands that would benefit from management have also been selected for regeneration harvest, including recent clearcuts and white pine plantations with low diversity and wildlife value. We believe the project should focus all regeneration harvests in such stands.
The potential changes make much less progress in addressing other issues, such as the sheer scale of the timber harvests. The Forest Service plans to cut overstory trees on just over 2,000 acres, highly concentrated in the upper Cooper Creek watershed. Treatment stands form an irregular, contiguous swath over two miles on a side. To be fair, riparian corridors will split up the treatment areas and reduce the acreage somewhat. Conversely, the “high to moderate fire intensities” planned “for the south- and west-facing xeric ridges” will likely kill canopy trees in and adjacent to the silvicultural treatment areas, further opening the canopy. Natural disturbances, even hurricanes, rarely produce such concentrated blocks of canopy disturbance in the Southern Appalachians, and this approach differs from the more scattered cuts the Forest Service has used in past decades.
The location of specific treatments also raises concerns. The pine/pine-oak thinning on Bryant Creek, the largest tributary of Cooper Creek in the project area, encompass excellent white pine habitat. White pine is not “off-site” in these areas, and the forests are mature enough that natural canopy gaps are beginning to form on their own. Given the extent of other canopy disturbances elsewhere in this project, we believe these stands have their greatest value if simply left alone.
Similarly, most of the woodland thinning treatments seem a poor match for site conditions. In attempting to visit all of the stands where mature canopy trees would be cut, we have seen only two stands with stunted oak canopies where we believe an historic fire regime would be sufficient to maintain woodlands. The generally rich soils and high rainfall across the higher elevations of the project area mean tree growth rates are moderate to high in most stands targeted for woodland, and we believe enough trees could regenerate between historic disturbances to maintain a closed canopy. These treatments would also remove mature oaks, which would be a significant loss for wildlife, and appear to be woodland creation rather than restoration.
In addition to ecological issues, the current location of treatments appears to conflict with the 2004 Chattahoochee-Oconee National Forests Land and Resource Management Plan. The plan, which sets goals, objectives, and rules for managing the forest, describes management prescription 7.E.1 (dispersed recreation areas) as “unsuitable for timber production; not suitable” with a caveat for other plan goals and objectives. The entire project area north of Duncan Ridge is within a 7.E.1 prescription, and includes commercial treatments in 14 stands.
Cooper Creek and adjacent sections of Duncan Ridge provide both exceptional recreational opportunities and exceptional biological value. Past timber harvests, settlements, and altered disturbance regimes have changed this unique landscape and created forest health issues. The Forest Service’s goals in this project of improving wildlife habitat, improving forest health, and restoring ecosystems are certainly commendable goals. However, care must be taken to ensure that the restoration is truly restoration and that the scale of the treatment matches the scale of the problem.