Southern Appalachian Mountain Region Research Articles

Seasonal Climate Trends, the North Atlantic Oscillation, and Salamander Abundance in the Southern Appalachian Mountain Region

Abstract The North Atlantic Oscillation (NAO) is a large-scale climate teleconnection that coincides with worldwide changes in weather. Its impacts have been documented at large scales, particularly in Europe, but not as much at regional scales. Furthermore, despite documented impacts on ecological dynamics in Europe, the NAO’s influence on North American biota has been somewhat overlooked. This paper examines long-term temperature and precipitation trends in the southern Appalachian Mountain region—a region well known for its biotic diversity, particularly in salamander species—and examines the connections between these trends and NAO cycles. To connect the NAO phase shifts with southern Appalachian ecology, trends in stream salamander abundance are also examined as a function of the NAO index. The results reported here indicate no substantial long-term warming or precipitation trends in the southern Appalachians and suggest a strong relationship between cool season (November–April) temperature and precipitation and the NAO. More importantly, trends in stream salamander abundance are best explained by variation in the NAO as salamanders are most plentiful during the warmer, wetter phases.

A taxonomic reassessment of theDrunella lata(Morgan) species complex (Ephemeroptera:Ephemerellidae) in northeastern North America

For many years the Drunella lata complex of eastern North America consisted of 4 recognized species: 3 described from the Northeast, Drunella lata (Morgan), Drunella cornuta (Morgan), and Drunella cornutella (McDunnough), and 1, Drunella longicornis (Traver), from the southern Appalachian Mountains region. Recently, all 4 were synonymized to a single species (D. lata [Morgan], by priority) because morphological variation was perceived to be continuous and historical characterizations of species were viewed as arbitrary. We used genetic, morphometric, and life-history data to reevaluate D. lata, D. cornuta, and D. cornutella in northeastern North America, where all 3 morphotypes coexist in certain catchments and often in the same reach of stream. Pairwise genetic comparisons of coexisting morphotypes revealed fixed allelic differences at 6 to 10 of 19 allozyme loci, showing reproductive isolation among D. cornuta, D. cornutella, and D. lata even within the same reach of stream. Morphometric studies confirmed their distinction by uncovering significant differences in a suite of characters, some with nonoverlapping ranges (i.e., diagnostic). The 3 taxa also were shown to be segregated ecologically by consistent differences in seasonality, thermal requirements, and spatial distribution. We conclude that D. cornuta, D. cornutella, and D. lata are all worthy of full species status, and so reinstate D. cornuta and D. cornutella. Diagnostic descriptions are provided and existing keys emended.

Determining the Extent of Market and Extent of Resource for Stated Preference Survey Design Using Mapping Methods

Determining the appropriate survey population and the commodity to be valued are among the most fundamental design decisions for stated preference (SP) surveys. However, often little information is available about who in the population holds measurable value for the resource (the extent of the market) and their perceptions regarding the scope of the resource to be valued (the extent of the resource). In this paper, we present a novel approach using cognitive mapping interview techniques to shed light on these design questions. The method also provides ancillary information that assists in the interpretation of information collected during focus groups and through SP survey administration. The approach was developed and tested as part of an ongoing study on environmental degradation associated with acidification in the Southern Appalachian Mountain region. Although damage from acidification in the study region is broad, it is not clear whether residents of this region care, in both a use and nonuse sense, about resources in their states of residence, in neighboring states, on public lands, or more broadly across the region. From a pilot study, we found that participants show a significant home-state preference in the number and size of natural areas that they value within the larger Southern Appalachian Mountain region. However, this preference is not strong enough to suggest that the market for improving these resources is solely constrained to residents of the state in which the resource is located.

Fuels on disturbed and undisturbed sites in the southern Appalachian Mountains, USA

Fuel distribution in the southern Appalachian Mountain region was measured in over 1000 study plots that were stratified by topographic position (aspect and slope position) and disturbance history. Few fuel differences occurred among topographic positions for undisturbed plots, indicating that fuel accumulation is no greater on highly productive sites than on less productive sites. Litter was slightly higher on undisturbed upper slopes (4.2 t/ha) than on lower slopes (3.7 t/ha) but woody fuels showed no significant differences. Rhododendron ( Rhododendron spp.) and mountain laurel ( Kalmia latifolia L.) were less common than expected, occurring on 25% and 42% of sampled plots, respectively. Disturbance history and type played a greater role in determining fuel loads than did topographic position. Disturbances had occurred on 30% of sample plots within the past 10 years and were most common on exposed slopes. Litter was significantly lower in burned plots (3.5 t/ha vs. 4.0 t/ha in undisturbed plots). One-hour fuels (1.0 t/ha) were significantly higher on beetle-killed plots than on undisturbed plots (0.7 t/ha) while larger woody fuels tended to be greater in plots subjected to beetle attack, fire, and wind.

The Influence of Woody Encroachment Upon Herbaceous Vegetation in a Southern Appalachian Wetland Complex

Small isolated wetlands in the southern Appalachian mountain region contain a disproportionate amount of the region's rare and uncommon herbaceous species. Many of these herbaceous communities may be threatened by invading trees and shrubs. We investigated changes in vegetative communities between 1994 and 2001 and the impact of woody encroachment upon herbaceous wetland communities in a southern Appalachian wetland complex in western North Carolina. We conducted a quantitative investigation of herbaceous, shrub and tree vegetation in forested and unforested fen and floodplain wetland sites. Additionally, soil chemistry, water level and precipitation data were collected. We found that woody encroachment was the strongest predictor of diminished herbaceous wetland communities, while water levels had the strongest positive relationship with herbaceous coverage.

Spatial Distribution of Acid-sensitive and Acid-impacted Streams in Relation to Watershed Features in the Southern Appalachian Mountains

A geologic classification scheme was combined with elevation to test hypotheses regarding watershed sensitivity to acidic deposition using available regional spatial data and to delimit a high-interest area for streamwater acidification sensitivity within the Southern Appalachian Mountains region. It covered only 28% of the region, and yet included almost all known streams that have low acid neutralizing capacity (ANC ≤20 μeq l−1) or that are acidic (ANC ≤0). The five-class geologic classification scheme was developed based on recent lithologic maps and streamwater chemistry data for 909 sites. The vast majority of the sampled streams that had ANC ≤20 μeq l−1 and that were totally underlainby a single geologic sensitivity class occurred in the siliceous class, which is represented by such lithologies as sandstone and quartzite. Streamwater acid-base chemistry throughout the region was also found to be associated with a number of watershed features that were mapped for the entire region, in addition to lithology and elevation, including ecoregion, physiographic province, soils type, forest type and watershed area. Logistic regression was used to model the presence/absence of acid-sensitive streams throughout the region.

Relationships between NW flow snowfall and topography in the Southern Appalachians, USA

NW flow snowfall (NWFS) events are common occurrences at higher elevations (1500 to >2000 m a.s.l.) and on windward slopes in the Southern Appalachian Mountain region of the south- eastern USA. The spatial patterns of NWFS are strongly controlled by topography, resulting in pro- nounced spatial variability. The strong topographic and low-level convective forcing, coupled with low temperatures and strong winds, increases societal impacts. This paper analyzes the relationships between NWFS and various topographic and geographic (TOPO/GEOG) variables in the Southern Appalachians. We identified NWFS events on the basis of low-level wind direction, extracted values for the TOPO/GEOG variables from Digital Elevation Models (DEMs), and developed statistical rela- tionships between NWFS and the TOPO/GEOG variables. Using a multivariate regression model and GIS techniques, we also mapped mean annual NWFS across the region. Results indicate that eleva- tion and NW exposure are most strongly correlated with NWFS; however, the strength of these rela- tionships is mediated by temperature. In the colder NWFS events, the relative importance of eleva- tion is diminished, while NW exposure and distance to a NW slope are relatively more important. Additionally, we demonstrate that multivariate regression modeling in conjunction with GIS tech- niques can be an effective way to map snowfall patterns associated with specific wind directions, particularly when a strong topographic control is evident.

Trends in cloud water sulfate and nitrate as measured at two mountain sites in the Eastern United States:: Regional contributions and temporal changes compared with regional changes in emissions, 1986–1999

Air pollutant emissions in the US generally peaked in 1970, the year that the Clean Air Act was passed, and have declined since, except for oxides of nitrogen (NO x ), which have remained steady or slowly increased. In 1995 Phase 1 of the Clean Air Act Amendments (CAAA) of 1990 went into effect resulting in a sharp drop in sulfur dioxide (SO 2) emissions in most areas. Pollutant concentrations measured in precipitation and ambient air generally reflected the changes in emissions in most areas of the eastern US. Only the southern Appalachian Mountain region did not see an appreciable improvement in precipitation acidity over the last decade. Previous studies of cloud chemistry in the eastern US found no pattern of temporal trends, possibly because of large year-to-year variation in meteorology. In this paper, we present spatial and temporal trends in SO 4 2− and NO 3 − concentrations of cloud water samples collected in warm seasons only at two mountain sites (Whiteface Mountain, NY and Whitetop Mountain, VA). This analysis is based on a combined cloud chemistry data-set collected by EPA's Mountain Cloud Chemistry Program (MCCP) (1986–1989) and Mountain Acid Deposition Program (MADPro) (1994–1999). Sample concentrations were (1) normalized by liquid water content (to reduce within-cloud variation) and (2) segregated into 90° arrival quadrants based on 36 h back trajectory analysis (to diminish between-cloud or meteorological variation). For each quadrant at the two sites, annual (12 month) county emissions of SO 2 and NO x were compiled out to 600, 1000, and1600 km, and these values were compared with the annual means (warm season only) of normalized SO 4 2− and NO 3 − concentrations in hourly samples of cloud water (segregated by back-trajectory) collected at each site. For the period 1987–1999, Quadrant 3 (SW) for Whiteface Mt. and Quadrants 3 (SW) and 4 (NW) for Whitetop Mt. had the highest SO 2 emissions and showed the largest decline in SO 2 emissions after the CAAA was implemented. These same quadrants which had the largest decrease in emissions showed significant declines in cloud water SO 4 2− over the time period. NO x emissions were highest in Quadrant 3 for Whiteface Mt. and in Quadrants 1 and 4 for Whitetop Mt. Only in Quadrant 1 at Whitetop Mt. did NO x emissions decrease during the study period (1987–1999). Cloud water NO 3 − showed no consistent pattern at either mountain site with some quadrants having higher cloud water NO 3 − values after Phase 1 of the CAAA and other quadrants having little change in cloud water NO 3 − values.

Landscape distribution and characteristics of large hurricane-related canopy gaps in a southern Appalachian watershed

Hurricane-related winds are a major source of disturbance in coastal ecosystems of the southern United States, but their effects on forests in the southern Appalachian Mountains, >400 km inland, have seldom been documented. In October 1995, remnant winds of Hurricane Opal caused windthrow of individual and patches of trees throughout the mountainous region of western North Carolina, USA. The 2-day storm event was accompanied by over 150 mm of precipitation and gusty, predominantly southeasterly winds with peak velocities at low elevations of up to 26 m/s; peak velocities were over 40% greater at high elevations. In a landscape-scale case study, we spatially located the population of large canopy gaps (groups of ≥10 windthrown trees) within a 2400 ha watershed to determine frequency of occurrence on basin and highland landscape types, dimensions, association with topographic features, and direction of treefall as a measure of wind vectors. The distribution of large gaps was not random within the watershed and occurred at an average density of 1 per 39 ha in the basin (elevation <700 m), which is characterized by hills of low relief and soils with high clay content. In comparison, gap density averaged 1 per 192 ha on the surrounding highlands (elevation >700 m) of high relief and soils with low clay content. Gaps on both landscape types occurred with greater frequency on sites of southeasterly aspect. Sizes of large canopy gaps ranged from 0.1 to 3.9 ha (average 0.7 ha) and were not correlated with landscape type or topography. Gap shape tended to be linear and averaged 2.3 times longer than wide. Direction of mean treefall among gaps was predominantly northwesterly and was strongly associated with aspect on highland, but less so in basin landscape types. Variation in mean treefall direction among gaps suggests that gaps were created by individual gusts of high-velocity, linear winds. A logistic discriminant model based on elevation, azimuth, and slope gradient correctly classified 78% of the study sites. However, gap size and association with topographic features were similar between basin and highland landscapes. Although the southern Appalachian Mountain region is over 400 km from the Gulf of Mexico and the Atlantic Ocean, results from our study suggest that strong winds from hurricane remnants can influence forest structure, with greater impacts on basin than highland landscapes.

Regional model projections of future effects of sulfur and nitrogen deposition on streams in the southern Appalachian Mountains

We constructed a model‐based evaluation of current and future effects of atmospheric S and N deposition on aquatic resources in the eight‐state southern Appalachian Mountains region. Modeling was conducted with the MAGIC model for about 40 to 50 sites within each of three physiographic provinces, stratified by stream water acid neutralizing capacity (ANC) class. Simulations were based on assumed constant future atmospheric deposition at 1995 levels and on three regional strategies of emissions controls provided by the Southern Appalachian Mountains Initiative (SAMI), based on the Urban to Regional Multiscale One‐Atmosphere model. The National Stream Survey statistical frame was used to estimate the number and percentage of stream reaches in the region that were projected to change their chemistry in response to the emissions control strategies. There was a small decline in the estimated length of projected acidic (ANC ≤ 0) streams in 2040 from the least to the most restrictive emissions control strategy, but there was little difference in projected stream length in the other ANC classes as a consequence of adopting one or another strategy. However, projections of continued future acidification were substantially larger under a scenario in which S and N deposition were held constant into the future at 1995 levels. Model results suggested that the percent of potentially acid‐sensitive streams having chemistry that is chronically unsuitable for brook trout would increase slightly between 1995 and 2040 under all except the most restrictive emissions control strategy.

Regional-scale impacts of Phase I of the Clean Air Act Amendments in the USA: the relation between emissions and concentrations, both wet and dry

A comparison of data records in the 1990s, both before (1991–1994) and after (1995–1997) implementation of Phase I of the Clean Air Act Amendments (CAAA) of 1990 for the eastern US, shows a significant reduction in SO 2 emissions for most states, except for Texas, North Carolina, Illinois, Florida, and Alabama. However, of the major NO x emitting states, only two eastern states (New York and Pennsylvania) show significant declines in NO x . A pattern of large declines in SO 2 emissions (>20%) after CAAA implementation, and large declines in precipitation SO 4 2− and H +, as well as air concentrations of SO 2 and SO 4 2− (components of dry deposition), exists for most regions of the eastern US. In most cases, the emission/concentration relations are close to 1 : 1 when the source region based on 15-h back trajectories is used for the New England region, and source regions based on 9-h back trajectories are used for the six other eastern US regions that were studied. The southern Appalachian Mountain region, an acid-sensitive area receiving high levels of acidic deposition, has not seen an appreciable improvement in precipitation acidity. This area has also shown the least improvement in wet and dry sulfur concentrations, of the areas examined. Precipitation base cations (Ca 2+ and Mg 2+) show a pattern of either increasing or level concentrations when comparing 1990–1994 to 1995–1998 data, for six of the seven regions examined. Ammonium concentrations have generally changed <10%, except for the Illinois and southern Appalachian Mtn. regions, which increased >15%.

Modeling Pollutant Transport during High-Ozone Episodes in the Southern Appalachian Mountains

Abstract Airflow patterns and pollution transport in the southern Appalachian Mountains region of the southeastern United States are examined using mesoscale meteorological models and a Lagrangian particle dispersion model (LPDM). The two primary goals of this work are 1) to identify a meteorological modeling methodology that can be used in regional photochemical modeling, and 2) to identify large regional ozone precursor sources that may impact the southern Appalachians during periods having high ozone levels. Four episodes characterized by measured high levels of ozone (1-h average concentrations greater than 90 ppb) at remote monitoring sites are the focus of the modeling efforts. To address the first goal, several methods of airflow modeling involving varying degrees of complexity are examined to find one that reliably simulates the complex wind patterns that occur. A hydrostatic model with homogeneous initialization, a nonhydrostatic model with homogeneous initialization, and a nonhydrostatic model w...

Characterization of Ambient Ozone Levels in the Great Smoky Mountains National Park

Abstract Ambient ozone data collected at two sites in the Great Smoky Mountains National Park (GSMNP) are summarized and compared with data from an urban and a low-elevation rural site. The ozone climatology in the park is found to be similar to that of other remote sites in the southern Appalachian Mountain region. As expected, terrain elevation is identified as a major factor influencing local ozone levels. Episodes of high ozone concentrations (≥90 ppb) in the park are shown to be primarily attributable to the transport of ozone into the park from outside. Backward air trajectories computed for high-ozone episodes in the GSMNP reveal that no preferred source regions exist, although some episodes appear to be associated with transport from urban areas.

Body Size and Metabolic Rate in Salamanders

Body Size and Metabolic Rate in Salamanders

The Decline of Fertility in the Southern Appalachian Mountain Region

This study investigates the decline of fertility in the Southern Appalachian Mountainl Region. Fertility rates of the white population were computed for each of the 190 counties included in the region for the years 1930, 1940, 1950, and 1960. Four measures of fertility were used: (1) the crude birth rate, (2) the child-woman ratio, (3) the general fertility rate, and (4) the general fertility rate indirectly standardized to the age distribution of U.S. white women 15 to 44 years of age in 1950. hypothesis was supported that the recent decline in fertility was associated with net out-mnigration, which is highly selective of young adults. Net out-migration did not, however, account for the greater part of the decline. ecological pattern of declining fertility showed the lowest rates to be in the metropolitan areas and in the more prosperous valley regions, while highest rates continued in the highland areas. T he people of the Southerni Appalachianl Mountains have had one of the higlhest reproduction rates of any major regioni of the United States during the present century.1 During the 1950-60 decade, however, birth rates in the Region dropped below the inatiolnal rate.2 decline was particularly marked in somle of the highly rural counties, most of which have also been characterized by heavy migration losses. As a consequence of the declining fertility combined with net-migration loss, the population of the region decreased between 1950 anid 1960 for the first time since census data have been available. In order to understand 1nore fully the forces. operatinlg to bring about the decline of fertility in the area, an investigation was made of white fertility rates in each of 190 counties included in the region for the years 1930, 1940, 1950 and 1960.3 This region has recently been the object of an extensive social and econiomic survey because it remains one of the largest economic problem areas in the nationi.4 economic difficulties of the regioln are traceable in large measure to anl imbalance of population and resources, a situation that was. clearly recognized in an earlier regionlal survey published in the 1930's.4 Although there has been a tremiendous outflow of migrants in recent decades, the 1960 population of the region was nearly a fifth greater than that of 1930, and only about three percent less than that of 1950. During the 1950-60 decade, according to Browvn and Hillery,6 the regionall rate of net migrationl loss was 19 percent of the 1950 pop* Paper presented at the annual meetings of the Rural Sociological Society, Washingtoni, D. C., August 1962. 1 National Resources Committee, Thle Problemsts of a Changing Populationb (Washington, D. C.: United States Government Printing Office, 1938), pp. 122-123; Carle C. Zimmerman and Richard F. DuWors, Gr-aphic Regiontal Sociology (Cambridge, Mass.: Phillips Book Store, 1952), pp. 45 and 53; L. C. Gray, et al., Eco-nonzic and Social Problems of the Southern Appalachians, Miscellaneous Publicationi No. 205, U. S. Department of Agriculture (Washington, D. C.: U. S. Government Printinig Office), p. 5; Gilbert W. Beebe, Conttraception anid Fertility in the Southern Appalachiants (Baltimore: Williams and Wilkins Company, 1942), pp. 18-19. 2 John C. Belcher, Population Growth and Characteristics, Chapter 3 in Thomas R. Ford (ed.), Thle Southern Appalachian RegioTn: A Survey (Lexington, Kentucky: University of Keintucky Press, 1962), pp. 43-44. 3The Southern Appalachiaii Region as defined for the present study includes 190 mountain-area counties in Kentucky, Tennessee, West Virginia, Virginiia, Alabama, Georgia, and Nortlh Carolina. 4 Thomas R. Ford (ed.), Soitthern Appalachian Regiont: A Sitrvey (Lexinigton, Kentucky: Uniiversity of Kentucky Press, 1962). 5 Gray, et al., op. cit., pp. 3-6. 6 James S. Brown and George A. Hillery, Jr., The Great Migration, 1940-1960. Chapter 4 in Ford (ed.), op. cit.. p. 59. This content downloaded from 157.55.39.124 on Wed, 20 Jul 2016 05:32:06 UTC All use subject to http://about.jstor.org/terms

Some Climate-Altitude Relationships in the Southern Appalachian Mountain Region

The variation of certain climatic elements with elevation is examined for Tennessee-North Carolina portions of the Southern Appalachian region. Regression equations relating elevation to annual, January, and July mean temperatures and mean daily temperature ranges and to length of growing season are derived. Early growing-season data for 15 mountain-valley systems in western North Carolina are examined and regression lines developed relating length of growing season to elevation for valley and summit locations. These regression lines adjusted for departure of early data from long-term averages appear applicable to recent long-term data and present a useful means of refining the growing season-elevation relationship. Although a satisfactory precipitation-elevation relationship is unattainable due presumably to slope and exposure effects, an estimate is given of the mean annual snowfall-elevation relationship. Graphs are presented showing the variation of potential evapotranspiration with elevation based on computations for selected locations from 1075 ft to 6684 ft; results are believed representative of the entire area under consideration.