- Fresh Air
- Natural Background Visibility
- Cove Hardwoods
- Water and Streams
- Floral Diversity and Vegetation
- Geologic Features
- AQRV Type VISIBILITY
- AQRV Type WATER
- Pollutant Exposure Concern Thresholds
- General Information
The Sipsey Wilderness is located in northwest Alabama at the juncture of three separate geologic areas: the Appalachian Plateau, the Cumberland Plateau and the Coastal Plain. The vegetation from these three unique environments blend into a remarkable diversity of species, with overlapping ranges creating many unusual plant associations. The Sipsey is a 12,726 acre area of swift streams, waterfalls, sandstone cliffs, undisturbed gorges, majestic hardwood forests, wildflowers, birds and animals.
Air Quality Related Values
For many visitors, the lack of odors is an important part of the wilderness experience. The air in the Sipsey is odorless, except for brief encounters with natural scents such as: springtime honeysuckle, the fragrance from a distant cookfire or the fresh smell of a cascading stream.
Scents such as the occasional whiff of honeysuckle convey a sense of pleasant surprise. The absence of odors in general portrays cleanness, healthfulness and wholesomeness; feelings which are prerequisite to enjoying most other wilderness values.
|Natural Background Visibility|
|Site Specific Rayleigh scattering coefficient:||Clearest 20% Natural||Clearest 20% 2000-2004 Baseline||Haziest 20% Natural||Haziest 20% 2000-2004 Baseline||Average Annual Natural||Annual Average 2000-2004 Baseline|
|Standard Visual Range (km)||252||84||135||22||188||44|
|Haze Index (dv)||5.02||15.57||10.99||29.03||7.79||21.96|
The Sipsey Wilderness lies in the southern extremity of the Cumberland Plateau. The bluffy nature of this topography has limited access for logging since the area was settled. Because of this inaccessibility, some 120 acres of old-growth forest remains within the Sipsey. Also, some stands of the second growth forest have reached sufficient size to convey the perception of old-growth forest.
Species associated with these cove hardwood stands include: hemlock, a variety of oaks, hickory, beech and yellow poplar. Alabama's largest tree, a yellow poplar, is a well known focal point within the Sipsey. This tree is approximately 150 feet tall and over 500 years old.
When viewed, these stands of large cove hardwoods convey feelings of magnificence and primeval simplicity. There is also a sense of timelessness, a connection to past and future generations, which is confirmed by the knowledge that these areas lie within a protected wilderness.
Water and Streams
The Sipsey Wilderness has many perennial springs and creeks which collect, eventually, into the Sipsey Fork. As they follow their course through the landscape, these waters flow through numerous riffles, pools and cascades. Hikers find the pools and cascades to be convenient places to rest. A notable feature of the water is its turquoise tint which persists long after storms and showers have departed.
Due to a lack of certain minerals, these waters have a relatively low productivity. Nevertheless, they provide habitat for a variety of aquatic and littoral flora and fauna. Particular species of interest include: the southern cave fish, the flattened musk turtle (T&E) and the lush green moss that covers the rocks along the channel.
These water features convey a variety of feelings to the visitor. There is curiosity at the 'turquoise' tint and intrigue as minnows and crayfish rush for cover. Although the endangered flattened musk turtle is rarely seen, there is satisfaction in knowing that it will always have a home. The urgent rush of spring runoff changes to a peaceful trickle through moss covered rocks in the summer. While the deeper pools are forbiddingly cold in March, they are invitingly cool in August. These feelings are amplified through the knowledge that the nature of this wilderness will persist.
Floral diversity and Vegetation
The Sipsey Wilderness is well known throughout the State for its spring wildflower display. Several species of sensitive plants exist within the Sipsey and on adjacent portions of the National Forest. One species of fern is currently being classified, as it may already be on the T&E plant list. During the spring, many botanical clubs visit the Sipsey on plant identification trips.
The Sipsey's floral display generates a variety of feelings. The casual hiker experiences a sense of serendipity. There is an appreciation that nature can provide such delicate beauty in a harsh environment, also a sense of primeval simplicity. The botanist comes to the Sipsey confident that last year's display will again be available for observation and instruction. He departs with anticipation of next year's spring renewal.
Vegetation in general makes up a large part of a visitor's experience in the Sipsey. That the vegetation portrays an overall image of health and vigor is a prerequisite to a visitor's enjoyment of other wilderness values.
The caves, cliffs, bluffs and gorges cut out of the sandstone bedrock are distinct features of the Sipsey Wilderness. In the lower portions of the watershed, streams have cut deep enough (300 to 500 feet) to reveal a limestone formation. These geologic features, along with the fossils captured in them, portray the timeless and intractable side of nature.
When viewed close-up however, these sandstone surfaces display something else. Observers wonder at how the lichens and mosses thereon cling so persistently and patiently to life.
Protecting these rock surfaces from air pollution effects will have an additional value. Petroglyphs, the art forms that prehistoric man carved in the rocks, have been documented on the walls of a bluff shelter just outside the Wilderness boundary. Although no petroglyphs have yet been inventoried in the Wilderness, it is probable that some exist and require protection.
Resource Concern Thresholds
|AQRV Type: VISIBILITY|
|Sensitive Receptor||Sensitive Receptor Indicator||Thresholds|
|Natural Visibility||Light Extinction||In specific Class I areas to maintain consistency with Regional Haze implementation plans or BART, the visibility threshold for concern is not exceeded if the 98th percentile change in light extinction is <5% for each year modeled, when compared to the 20% best natural background values.|
|Natural Visibility||Light Extinction||For sources generally further than 50 km from a Class I area, the visibility threshold for concern is not exceeded if the 98th percentile change in light extinction is <5% for each year modeled, when compared to the annual average natural condition value for that Class I area.|
|Plume Blight||Absolute Contrast||Screening Analysis: For near field sources (within 50 km of a Class I area), no additional analysis will be requested if screening analysis of a new or modified source can demonstrate that its emissions will not cause a plume with hourly estimates of DeltaE (color difference index) greater than or equal to 2.0 or the absolute value of the contrast greater than or equal to 0.05 when modeled against natural conditions.|
|Plume Blight||Absolute Contrast||Refined Analysis: No further analysis will likely be requested if a new or modified source can show that impacts from a new or modified source will stay with the threshold of DeltaE <1.0 and |C| <0.02 modeled against natural conditions.|
|Plume Blight||Color Difference Index||Screening Analysis: For near field sources (within 50 km of a Class I area), no additional analysis will be requested If screening analysis of a new or modified source can demonstrate that its emissions will not cause a plume with hourly estimates of DeltaE (color difference index) greater than or equal to 2.0 or the absolute value of the contrast greater than or equal to 0.05 when modeled against natural conditions.|
|Plume Blight||Color Difference Index||Refined Analysis: No further analysis will likely be requested if a new or modified source can show that impacts from a new or modified source will stay with the threshold of DeltaE <1.0 and |C| <0.02 when modeled against natural conditions.|
|AQRV Type: WATER|
|Sensitive Receptor||Sensitive Receptor Indicator||Thresholds|
|Perennial Streams||Acid Neutralizing Capacity||In perennial streams, no more than 0.1 microequivalent/liter measurable decrease in acid neutralizaing capacity is acceptable|
|Perennial Streams||Chronic Acid Neutralizing Capacity||To maintain healthy biological functioning in perennial streams, the chronic acid neutralizing capacity must be >= 25 ueq/l.|
|Perennial Streams||Chronic pH||To maintain healthy biological functioning, the chronic pH of perennial streams must be >= 6.0.|
|Perennial Streams||Episodic Acid Neutralizing Capacity||To maintain healthy biological functioning in perennial streams, the episodic acid neutralizing capacity must be >= 0 ueq/l.|
|Perennial Streams||Episodic pH||To maintain healthy biological functioning, the episodic pH of perennial streams must be >= 5.5.|
|Perennial Streams||pH||In perennial streams, no more than 0.1 measurable decrease in pH is acceptable|
|Pollutant Exposure Concern Thresholds|
|Pollutant Exposures||Level Name||Thresholds|
|Nitrogen||DEPOSITION||Nitrogen deposition may be expected to cause cation leaching in soils when N levels are greater than 12 kg/ha/yr. Below 5 kg/ha/yr, negative effects to soil and vegetation are not expected|
|Nitrogen||EXCEEDANCE||The Deposition Analysis Threshold for nitrogen deposition below which estimated impacts from a source are considered negligible is 0.010. kilograms/hectare/year.|
|Ozone||W126||Biomass reduction of ozone sensitive species may occur when the W126 ozone metric (for April-September) is ≥ 14.5 ppm-hours. This should be evaluated in conjunction with the N100 value.|
|Ozone||N100||Biomass reduction of ozone sensitive species may occur when the number of hours from APRIL-SEPTEMBER with an ozone concentration greater than or equal to 0.100ppm equals or exceeds 4. This should be evaluated in conjunction with the W126 value.|
|Sulfur||DEPOSITION||Sulfur deposition may be expected to cause cation leaching and increased aluminum toxicity in soils when levels are greater than 20 kg/ha/yr. At 5 kg/ha/yr or below, sulfur negative effects to soil and vegetation are not expected.|
|Sulfur||EXCEEDANCE||The Deposition Analysis Threshold for sulfur deposition below which estimated impacts from a source are considered negligible is 0.010 kg/ha/yr.|
|Forest Service Administrative Unit(s):||Southern Region (Region 8) -- National Forests in Alabama|
|Elevation Range:||580 - 1,001 feet|
|Detailed wilderness information:||https://www.wilderness.net|
|GIS Map/Official Boundary:||https://www.wilderness.net/NWPS/|