32.6 Major Types of Analysis
els. Common sources of particulate matter are stationary sources, such as power plants or unpaved
roads, but there is considerable interest in the potential effects that prescribed fire might have on local conditions.
The Southeast has the poorest visibility in the
Eastern United States, and it is usually worst in the
summer months when the greatest numbers of people are viewing scenery in the mountains. Haziness
has intensified since the 1940s, and sulphur dioxide emissions are believed to be primarily responsible.
In addition to being an important component of
the recreation experience, visibility is specifically
addressed in the CAA. The CAA established a national goal of "prevention of any future, and the
remedying of any existing, impairment of visibility in mandatory Class 1 federal areas where impairment results from man-made pollution." The
majority of the visibility data used in the assessment was obtained in the seven Class 1 areas within
the assessment area. A description of current conditions was based on data collected through the
Interagency Monitoring of Protected Visual Environments (IMPROVE) network. Historical visibility data were based on information collected at airports since the 1950s.
Acid deposition has been the cause for great concern in the assessment area since the early 1980s
when some scientists began to attribute the death
of high-elevation spruce and fir forests to the effects of air pollution. Moreover, media reports repeatedly proclaimed that acid rain was killing lakes
and streams in the area. During the 1980s, the National Acid Precipitation Assessment Program
(NAPAP) carried out the National Stream Survey
to estimate the extent of stream resources affected.
The assessment team used these databases and
model results, together with site-specific investigations, to describe the acid-deposition threats to
aquatic resources. The assessment also reviewed
the EPA's findings to estimate stream reaches sensitive to acid deposition.
Ozone is potentially the most significant pollutant affecting forests in North America. Numerous
surveys within the Southern Appalachians have
reported ozone symptoms on sensitive plants.
Whether growth loss actually occurs depends on
the sensitivity of the plant species and environmental conditions such as soil moisture that affect
the plants' vulnerability to ozone.
32.6.2 Terrestrial Analysis
The Southern Appalachians are a diverse and complex region. The terrestrial resources are affected
481
by topography, geology, climate, soils, and the history of human use. The questions arising from public discussion and planning needs fell mainly into
two groups: What are the status and condition of
plant and animal resources, and what is the general
health of the forests?
Plant and Animal Resources
To address questions that dealt with species occurrence and frequency, it was first necessary to
narrow the species of concern down to a manageable number. More than 25,000 species are known
to inhabit the assessment area, but 472 were selected for study based on a number of selection criteria (Figure 32.5). Slightly more than half were
animals. Most of these species could be separated
into 19 groups based on similar habitat requirements (associations). Species associations helped
define the habitat characteristics that would be of
interest in the descriptive inventory.
Many characteristics of the landscape are useful
for describing habitat condition and suitability. The
terrestrial team gathered data and described habitat features as part of their analysis and in response
to the questions. In addition to the usual features
that include land use and land cover, forest type,
ownership, and ecological units, special emphasis
was given to the successional stages of vegetation
because of its significance for animal habitat.
About 84% of the terrestrial threatened and endangered species and 74% of the viability concern
species are associated with rare communities and
streamside habitats. These rare communities represent less than 3% of the assessment area, and 1 %
is high-quality habitat. Thus the future management
for species diversity will depend on managing these
habitats. Almost two-thirds is in private ownership.
The remaining small area is managed under federal
or state direction.
Forest Health
Forest health can be defined in many ways, but the
purpose of the assessment was to give an overview
of the most important factors that are affecting forest condition. These include natural and humaninduced disturbance, native and exotic pests, air
pollution, and changes in land use.
Historically, the most significant event affecting
the Southern Appalachians was the initial logging.
By 190 I, the condition of the region's forests and
streams had reached such a degraded state that the
secretary of agriculture was asked to make an assessment of their condition. This assessment ultimately led to passing the Weeks Act, which authorized establishing the National Forests in the
els. Common sources of particulate matter are stationary sources, such as power plants or unpaved
roads, but there is considerable interest in the potential effects that prescribed fire might have on local conditions.
The Southeast has the poorest visibility in the
Eastern United States, and it is usually worst in the
summer months when the greatest numbers of people are viewing scenery in the mountains. Haziness
has intensified since the 1940s, and sulphur dioxide emissions are believed to be primarily responsible.
In addition to being an important component of
the recreation experience, visibility is specifically
addressed in the CAA. The CAA established a national goal of "prevention of any future, and the
remedying of any existing, impairment of visibility in mandatory Class 1 federal areas where impairment results from man-made pollution." The
majority of the visibility data used in the assessment was obtained in the seven Class 1 areas within
the assessment area. A description of current conditions was based on data collected through the
Interagency Monitoring of Protected Visual Environments (IMPROVE) network. Historical visibility data were based on information collected at airports since the 1950s.
Acid deposition has been the cause for great concern in the assessment area since the early 1980s
when some scientists began to attribute the death
of high-elevation spruce and fir forests to the effects of air pollution. Moreover, media reports repeatedly proclaimed that acid rain was killing lakes
and streams in the area. During the 1980s, the National Acid Precipitation Assessment Program
(NAPAP) carried out the National Stream Survey
to estimate the extent of stream resources affected.
The assessment team used these databases and
model results, together with site-specific investigations, to describe the acid-deposition threats to
aquatic resources. The assessment also reviewed
the EPA's findings to estimate stream reaches sensitive to acid deposition.
Ozone is potentially the most significant pollutant affecting forests in North America. Numerous
surveys within the Southern Appalachians have
reported ozone symptoms on sensitive plants.
Whether growth loss actually occurs depends on
the sensitivity of the plant species and environmental conditions such as soil moisture that affect
the plants' vulnerability to ozone.
32.6.2 Terrestrial Analysis
The Southern Appalachians are a diverse and complex region. The terrestrial resources are affected
481
by topography, geology, climate, soils, and the history of human use. The questions arising from public discussion and planning needs fell mainly into
two groups: What are the status and condition of
plant and animal resources, and what is the general
health of the forests?
Plant and Animal Resources
To address questions that dealt with species occurrence and frequency, it was first necessary to
narrow the species of concern down to a manageable number. More than 25,000 species are known
to inhabit the assessment area, but 472 were selected for study based on a number of selection criteria (Figure 32.5). Slightly more than half were
animals. Most of these species could be separated
into 19 groups based on similar habitat requirements (associations). Species associations helped
define the habitat characteristics that would be of
interest in the descriptive inventory.
Many characteristics of the landscape are useful
for describing habitat condition and suitability. The
terrestrial team gathered data and described habitat features as part of their analysis and in response
to the questions. In addition to the usual features
that include land use and land cover, forest type,
ownership, and ecological units, special emphasis
was given to the successional stages of vegetation
because of its significance for animal habitat.
About 84% of the terrestrial threatened and endangered species and 74% of the viability concern
species are associated with rare communities and
streamside habitats. These rare communities represent less than 3% of the assessment area, and 1 %
is high-quality habitat. Thus the future management
for species diversity will depend on managing these
habitats. Almost two-thirds is in private ownership.
The remaining small area is managed under federal
or state direction.
Forest Health
Forest health can be defined in many ways, but the
purpose of the assessment was to give an overview
of the most important factors that are affecting forest condition. These include natural and humaninduced disturbance, native and exotic pests, air
pollution, and changes in land use.
Historically, the most significant event affecting
the Southern Appalachians was the initial logging.
By 190 I, the condition of the region's forests and
streams had reached such a degraded state that the
secretary of agriculture was asked to make an assessment of their condition. This assessment ultimately led to passing the Weeks Act, which authorized establishing the National Forests in the