Fraser Fir Research Articles

Extraction of Maltol from Fraser Fir: A Comparison of Microwave-Assisted Extraction and Conventional Heating Protocols for the Organic Chemistry Laboratory

Two methods for the extraction of maltol from Fraser fir needles are performed and compared in this two-week experiment. A traditional benchtop extraction using dichloromethane is compared to a microwave-assisted extraction using aqueous ethanol. Students perform both procedures and weigh the merits of each technique. In doing so, students see a trade-off between the ease of working with a highly volatile organic solvent and the selectivity that can be achieved with the greener solvent combination. This experiment combines multiple lab techniques, highlights the connections between chemistry and biology, and provides straightforward 1H NMR spectra to support the introduction of spectroscopy in first-semester organic chemistry.

Diversity and density of the EM fungal community present in high elevation Fraser fir forests of Great Smoky Mountains National Park

A study of the diversity and density of ectomycorrhizal (EM) fungi in two Fraser fir stands near Clingmans Dome, Great Smoky Mountains National Park was conducted over a period of three years. Plots were established in three naturally occurring age class treatments including mature tree, sapling, and low regeneration (no trees) sites. Lesser vegetation data were determined for nine plant species within all plots including two ferns and two grasses that impeded survival of Fraser fir seedlings. Diversity and densities of vegetation were significantly greater in low regeneration plots as compared to other treatments. For each plot bryophyte mat forest floor percent occurrence/cover was obtained and percent root colonization/sclerotia of the EM fungus taxa were collected from the three management treatments including 11 decomposers and 33 ectomycorrhizal species. Clavulina cristata occurred in 22.5% of all plots and had a frequency of 1.7% in low regeneration treatments. Four species of Laccaria occurred in 17.3% of all plots, and Laccaria laccata and L. laccata var. pallidifolia were the most common of these species, the former having the highest frequency of occurrence (1.9%) in low regeneration treatments. Four species of Cortinarius occurred in 10.3% of the plots, and Cortinarius anomalus s.l., the most common Cortinarius , occurred in 4.4% of all plots. Seven of the 44 species had significantly greater percent frequency among the three treatments, and six of those were the most frequent in sapling plot treatments at the two locations. Species found at the two locations were similar, although in 2009 their frequency values were greater than in 2010 and 2011 due to greater total precipitation. Mature and sapling plot frequency values were significantly greater than those for low regeneration sites due to the low establishment of Fraser fir. Significant results for species richness, diversity and evenness between years, locations and treatments are present below. Based on percent frequency values, Laccaria could be used in reforestation of Fraser firs in all plots. A project is underway to evaluate seedling establishment and survival following inoculation with Laccaria spp. on a low regeneration site at Mount Buckley.

Foliar uptake, carbon fluxes and water status are affected by the timing of daily fog in saplings from a threatened cloud forest

In cloud forests, foliar uptake (FU) of water has been reported for numerous species, possibly acting to relieve daily water and carbon stress. While the prevalence of FU seems common, how daily variation in fog timing may affect this process has not been studied. We examined the quantity of FU, water potentials, gas exchange and abiotic variation at the beginning and end of a 9-day exposure to fog in a glasshouse setting. Saplings of Abies fraseri (Pursh) Poir. and Picea rubens Sarg. were exposed to morning (MF), afternoon (AF) or evening fog (EF) regimes to assess the ability to utilize fog water at different times of day and after sustained exposure to simulated fog. The greatest amount of FU occurred during MF (up to 50%), followed by AF (up to 23%) and then EF, which surprisingly had no FU. There was also a positive relationship between leaf conductance and FU, suggesting a role of stomata in FU. Moreover, MF and AF lead to the greatest improvements in daily water balance and carbon gain, respectively. Foliar uptake was important for improving plant ecophysiology but was influenced by diurnal variation in fog. With climate change scenarios predicting changes to cloud patterns and frequency that will likely alter diurnal patterns, cloud forests that rely on this water subsidy could be affected.

Forest Response to the US 1990 Clean Air Act: The Southern Spruce-Fir Ecosystem

The history of the Black Mountains in North Carolina and the southern Spruce-Fir ecosystem has been fraught with widespread forest decline since the mid 1960’s. Balsam Woolly Adelgid attacks and acidic deposition were two of the most recognized causes of decline. Uncertainty arose about the future of these forests, and projections were made regarding the endangerment or extinction of the endemic Fraser fir ([Pursh] Poiret). This study analyzed data sets from a permanent plot network in the Black Mountains dating 1985, 2002, and 2012. Indications that the Fraser fir population is stabilizing from a “boom-bust” cycle of population growth and has entered the stem exclusion stage of forest stand development are evident. Fir live stem density increased more than 250% from 1985 to 2002, and then declined 40% by 2012 at the highest elevations in the forest. Overall, fir appeared to be more impacted on western facing slopes than eastern ones. The population of red spruce experienced a steady decrease in live stem counts, but an increase in live basal area through all years, and at all elevation classes (1675 m, 1830 m, and 1980 m), indicating a normal progression through stand development. Red spruce was also most negatively impacted on western facing slopes. Live stem density was significantly higher (P 0.001) than eastern plots, but live basal area was similar between the two aspects. Atmospheric deposition concentrations of the four main acidic molecules at Mt. Mitchell all peaked in 1998, but decreased by 2012. These reductions, occurring shortly after tightened regulations in the 1990 amendments to the Clean Air Act may have potential implications for increased forest resilience.

Impacts of human disturbance on the temporal stability of climate–growth relationships in a red spruce forest, southern Appalachian Mountains, USA

We used dendrochronological techniques to develop a tree-ring chronology (AD 1874–2009) from live trees and investigated the temporal stability of regional climate signals in the heavily disturbed red spruce (Picea rubens Sarg.) and Fraser fir [Abies fraseri (Pursh) Poir.] forest of Roan Mountain, Tennessee and North Carolina, USA. We performed bootstrapped correlation analyses in split data sets and moving intervals analyses to detect shifts in climatic sensitivity during periods of changing forest structure following disturbances. Most notably, a significant shift in red spruce temperature sensitivity occurred post-1930s, where positive growth responses to warm temperatures shifted to negative responses, and this shift coincided with a period of clearcut harvesting. As exogenous disturbances (i.e. ice storms, wind throw, and acidic deposition) are expected to continue altering the structure of this forest throughout the region, the climatic sensitivity of these species may become increasingly unstable.

Cloud immersion: an important water source for spruce and fir saplings in the southern Appalachian Mountains

Cloud immersion can provide a potentially important moisture subsidy to plants in areas of frequent fog including the threatened spruce-fir communities of the southern Appalachian Mountains (USA). These mountaintop communities grow only above ~1,500 m elevation, harbor the endemic Abies fraseri, and have been proposed to exist because of frequent cloud immersion. While several studies have demonstrated the importance of cloud immersion to plant water balance, no study has evaluated the proportion of plant water derived from cloud moisture in this ecosystem. Using the isotopic mixing model, IsoSource, we analyzed the isotopic composition of hydrogen and oxygen for water extracted from ground water, deep soil, shallow soil, fog, and plant xylem at the upper and lower elevational limits both in May (beginning of the growing season) and October (end of the growing season). Cloud-immersion water contributed up to 31% of plant water at the upper elevation sites in May. High-elevation plants of both species also experienced greater cloud immersion and had greater cloud water absorption (14-31%) compared to low-elevation plants (4-17%). Greater cloud water uptake occurred in May compared to October, despite similar rainfall and cloud-immersion frequencies. These results demonstrate the important water subsidy that cloud-immersion water can provide. With a warming climate leading potentially to increases in the ceiling of the cloud base and, thus, less frequent cloud immersion, persistence of these relic mountaintop forests may depend on the magnitude of these changes and the compensating capabilities of other water sources.

Seasonal Occurrence of Phytoseiid Mites (Acari: Phytoseiidae) in North Carolina Fraser Fir (Abies fraseri [Pursh] Poiret) Christmas Tree Plantations

The overwintering sites and seasonal abundance of phytoseiid mites were determined in North Carolina Fraser fir Christmas tree plantations. Potential overwintering sites for the mites include Fraser fir branches, Fraser fir bark, surface litter composed of Fraser fir needles, a mixture of fescue grass (Festuca spp.) and nimblewill (Mhlenbergia schreberi J.F. Gmelin.), mixed herbaceous debris from the previous growing season, and a monocultural cover crop of white clover (Trifolium repens L.). Twelve species of mites (n = 414) in the family Phytoseiidae were collected. Arrenoseius morgani (Chant) (n = 160), Typhlodromips sessor (DeLeon) (n = 156), and Typhlodromalus peregrinus (Muma) (n = 34) were the most abundant. During the spring and summer Fraser fir plantations with a ground cover consisting of white clover were compared with plantations with bare ground to assess the abundance and species composition of phytoseiid mites. A total of 512 phytoseiids representing 8 species was collected. Phytoseiid mite abundance was not significantly different between clover ground cover and bare ground plantations. Typhlodromips sessor (DeLeon), Typhlodromalus peregrinus (Muma), and Arrenoseius morgani (Chant) were the most abundant species in both plantation types.

Experimental cloud immersion and foliar water uptake in saplings of Abies fraseri and Picea rubens

Frequent cloud immersion events result in direct uptake of cloud water and improve plant water potentials during daylight hours in saplings of two dominant cloud forest species. In ecosystems with frequent cloud immersion, the influence on plant water balance can be important. While cloud immersion can reduce plant water loss via transpiration, recent advances in methodology have suggested that many species also absorb water directly into leaves (foliar water uptake). The current study examines foliar water uptake and its influence on daily plant water balance in tree species of the endangered spruce–fir forest of the southern Appalachian Mountains, USA. These mountain-top communities are considered relic, boreal forests that may have persisted because of the benefits of frequent cloud immersion. We examined changes in needle water content, xylem water potentials, and stable isotope values in saplings of the two dominant tree species, Abies fraseri and Picea rubens before and after a 24 h period of experimental cloud immersion. Both species exhibited foliar water uptake following immersion, evidenced by substantial changes in stable isotope values of extracted needle water that reflected the composition of the fog water. In addition, total needle water content improved 3.7–6.4 % following experimental submersion and xylem water potentials were significantly greater (up to 0.33 MPa) in cloud-immersed plants over control plants. These results indicate that foliar water uptake may be an adaptive strategy for utilizing cloud water and improving overall tree vigor in these most southerly distributed boreal species.

Carbon Isotope Discrimination, Gas Exchange, and Growth of Container-grown Conifers Under Cyclic Irrigation

The objective of this study was to quantify the effects of cyclic irrigation on growth and physiology of container-grown conifer species in pot-in-pot (PIP) production in the upper Midwest. Trees of four conifer species (Picea glauca var. densata, Picea pungens, Abies fraseri, and Pinus strobus) were grown in 25-L containers and assigned to one of four combinations of irrigation rate (low or high) and daily irrigation cycle frequency (one or four). Irrigation rates were based on common nursery practice in the region (2 cm rainfall equivalent/day) and one-half the standard rate (1 cm rainfall equivalent/day). Cyclic irrigation increased relative height growth and relative caliper growth of Pinus strobus by over 80% and 35%, respectively, compared with once-daily irrigation. The high-rate irrigation increased relative caliper growth of Picea pungens by 40% compared with the low rate. The effects of irrigation regime on needle- or shoot-level gas exchange varied by species and date of measurement. Carbon isotope discrimination (Δ13C) of needle and wood tissue was positively correlated (r ≥ 0.64, P < 0.001) with needle conductance to water vapor (gwv) and negatively correlated (r ≤ −0.60, P< 0.001) with intrinsic water use efficiency (WUEi). Carbon isotope discrimination of wood and needle tissue decreased with the low irrigation rate, indicating increased WUEi associated with reduced gwv. Cyclic irrigation had relatively little effect on Δ13C except for Pinus strobus. Our findings suggest that carbon isotope composition of wood and needle tissue provides a sensitive and accurate representation of plant response to varying moisture availability. From a water management perspective, identifying optimal irrigation rates appears to be more important than number of daily cycles for these crops grown in the midwestern United States.

Fraser Fir Tolerance and Weed Control with Hexazinone + Sulfometuron-methyl

Experiments were conducted to test a new herbicide for posttransplant application in Christmas trees. A premix containing 68.6% hexazinone and 6.5% sulfometuron-methyl was applied at 3.0, 4.5, 6.0, 7.5, and 9.0 oz/acre plus 0.25% v/v nonionic surfactant (NIS) to recently transplanted fraser fir (Abies fraseri) Christmas trees and trees transplanted for 1 year in Spring 2008. The treatments were repeated on the same plots in 2009 and 2010. At Gobles, MI, trees treated with 7.5 oz/acre of hexazinone plus sulfometuron had increased stem diameter, after one growing season, and trees treated with 9.0 oz/acre had reduced leader length the second year. After 3 years, fraser fir trees treated with hexazinone plus sulfometuron at 9.0 oz/acre had reduced tree height. Stem diameter, leader length, and number of leader buds were not statistically different from the untreated control. At Horton, MI, trees treated with 9.0 oz/acre of hexazinone plus sulfometuron had reduced leader length after 1, 2, and 3 years. After 3 years, trees treated with hexazinone plus sulfometuron at 6.0, 7.5, and 9.0 oz/acre were shorter than the untreated controls. There were no differences from the untreated trees in stem diameter of trees treated with hexazinone plus sulfometuron after 3 years.

Ecophysiological importance of cloud immersion in a relic spruce–fir forest at elevational limits, southern Appalachian Mountains, USA

Climate warming predicts changes to the frequency and height of cloud-immersion events in mountain communities. Threatened southern Appalachian spruce-fir forests have been suggested to persist because of frequent periods of cloud immersion. These relic forests exist on only seven mountaintop areas, grow only above ca. 1,500 m elevation (maximum 2,037 m), and harbor the endemic Abies fraseri. To predict future distribution, we examined the ecophysiological effects of cloud immersion on saplings of A. fraseri and Picea rubens at their upper and lower elevational limits. Leaf photosynthesis, conductance, transpiration, xylem water potentials, and general abiotic variables were measured simultaneously on individuals at the top (1,960 m) and bottom (1,510 m) of their elevation limits on numerous clear and cloud-immersed days throughout the growing season. The high elevation sites had 1.5 as many cloud-immersed days (75 % of days) as the low elevation sites (56 % of days). Cloud immersion resulted in higher photosynthesis, leaf conductance, and xylem water potentials, particularly during afternoon measurements. Leaf conductance remained higher throughout the day with corresponding increases in photosynthesis and transpiration, despite low photon flux density levels, leading to an increase in water potentials from morning to afternoon. The endemic A. fraseri had a greater response in carbon gain and water balance in response to cloud immersion. Climate models predict warmer temperatures with a decrease in the frequency of cloud immersion for this region, leading to an environment on these peaks similar to elevations where spruce-fir communities currently do not exist. Because spruce-fir communities may rely on cloud immersion for improved carbon gain and water conservation, an upslope shift is likely if cloud ceilings rise. Their ultimate survival will likely depend on the magnitude of changes in cloud regimes.

Recent results of Czech-American fir hybridization research

Fraser fir (Abies fraseri) Christmas tree plantations in North Carolina are infested by root rot caused by Phytophthora cinnamomi. This disease kills almost 100% of Fraser fir material and leaves the soil permanently infested. Control crossings of Mediterranean fir hybrids Abies cilicica × Abies cephalonica with Abies fraseri were performed to ensure possibly resistant hybrid material of desired Christmas tree parameters. Pollen of various clones of A. fraseri was shipped to the Czech Republic by NCSU. Control pollinations were performed in April/May 2010 and 2011 in our hybridization seed orchards. Female strobili were isolated in the period of their highest receptibility. Cones were collected during September. Cones were dried and completely disintegrated. Basic parameters of cones and seeds were assessed for each seed lot. Seed samples of the individual seed lots were X-rayed for assessment of the final share of full seeds. In 2010, the most successful combination CZ2 × NC81 brought 7% of viable seeds. In 2011 the most successful combination was CZ2 × NC26 with 18% of viable seeds.

Susceptibility of Fraser, Canaan, and Nordmann Fir to Root Rot Incited by Phytophthora cactorum and Phytophthora drechsleri

The susceptibility of fraser fir (Abies fraseri), canaan fir (A. balsamea var. phanerolepis), and nordmann fir (A. nordmanniana) to phytophthora root rot (PRR) incited by Phytophthora cactorum or P. drechsleri was assessed in two experiments in central Pennsylvania. In an 8-week greenhouse study, seedlings and transplants growing in soilless substrate were inoculated with Phytophthora in flooded and non-flooded settings. In an 8-week outdoor study conducted in raised planting boxes filled with soil, transplants were inoculated with Phytophthora species in well-drained and poorly drained soil. Based on foliar disease ratings, mortality rates, and dry shoot and root weights, differences in susceptibility to P. cactorum and P. drechsleri existed between these true fir (Abies) species. Fraser fir was very susceptible to P. cactorum and P. drechsleri. Canaan fir had strong resistance to P. cactorum and P. drechsleri in well-drained settings but was susceptible in poorly drained settings. Nordmann fir had very strong resistance to P. cactorum and P. drechsleri in both well-drained and poorly drained settings.

Regeneration responses to exogenous disturbance gradients in southern Appalachian Picea-Abies forests

Because of the devastation caused by the combined impacts of the balsam woolly adelgid (Adelges piceae; BWA, a non-native insect) and chronic acid deposition, Picea-Abies (spruce-fir) forests are one of the most threatened vegetation communities in North America. Endemic Abies fraseri (Fraser fir), the dominant overstory species in these forests, has experienced near complete overstory mortality as result of the adelgid. Observed forest regeneration patterns suggest high spatial variability, with dense patches of Rubus spp. (blackberry), A. fraseri, and deciduous regeneration repeating across the landscape. To quantify the spatial variability and density of A. fraseri, Picea rubens (red spruce), and deciduous regeneration in these forests, we sampled 60 randomly selected plots within Picea-Abies forests of Great Smoky Mountains National Park (GSMNP). As a measure of local variability in regeneration, we used regeneration density within 30 1×1m subplots per plot to calculate a coefficient of within-plot variation for each species. Despite the impacts of the BWA and chronic acid deposition, A. fraseri remained an important component of southern Appalachian Picea-Abies forests at elevations above 1750m. Density of A. fraseri in all size classes was associated with time since disturbance by BWA infestation. On plots where A. fraseri regeneration occurred, its local variability (among 30 subplots) was significantly greater than that of P. rubens or deciduous species. Regression models attributed this local-scale variability in A. fraseri regeneration to the influence of elevation, Rubus spp. cover, B-horizon nitrogen concentration, and O-horizon calcium to aluminum ratio. We propose that co-occurring gradients of BWA-induced mortality and acid deposition have created patches of increased light and nitrogen availability, which have increased competition from ruderal species such as Rubus spp. Additionally, our results suggest that high soil aluminum content relative to calcium may exclude A. fraseri from certain locations, further contributing to the local variability of A. fraseri regeneration.

Soil Carbon Stability Responds to Land‐Use and Groundcover Management in Southern Appalachian Agroecosystems

Soil C storage can be altered by land‐use conversion and by agroforestry management techniques such as weed management and fertilization. The Southern Appalachian Mountains have a mosaic of land uses, including Christmas tree [Abies fraseri (Pursh) Poir] farms, pastures, and unmanaged forests. We contrasted Christmas tree farm soil C pools with those of adjacent pastures and forests to estimate C storage differences due to land use. We partitioned soil C into fractions delineated by stability, an important determinant of long‐term C sequestration potential. Soil C pools were quantified across a chronosequence of tree farms that varied in cultivation duration (3–51 yr) and interspace groundcover. We found that the duration of tree cultivation did not alter tree farm soil C pools; however, recalcitrant C pools were twice as high when interspace groundcover increased from 35 to 70%. Total, active, slow, and recalcitrant soil C pools were highest in forests compared with pastures and tree farms. Tree farm soils had about 25% lower C concentration than the adjacent forest soils, but because there was no downward trend with duration of cultivation, the reduction probably occurred rapidly following initial clearing. Tree farms and forests had longer mean residence times for active and slow C than pastures, potentially indicating an influence of woody root production. Our findings suggest that maintaining tree farm interspace vegetation, possibly through reduced herbicide use, can enhance soil C sequestration.

Growth and Physiological Response of Fraser Fir [Abies fraseri (Pursh) Poir.] Seedlings to Water Stress: Seasonal and Diurnal Variations in Photosynthetic Pigments and Carbohydrate Concentration

Four-year-old seedlings of Abies fraseri [(Pursh) Poir] (fraser fir) were grown in semicontrolled conditions in hoop houses with five watering regimes (0.00, 0.62, 1.25, 2.50, and 3.70 cm/week) with the goal of determining the seasonal variation in the physiological response to drought stress. Drought stress was monitored by measuring predawn (Ψpd) and midday (Ψmd) potentials in a subset of plants from each treatment. Physiological variables monitored were chlorophyll fluorescence (Fv/Fm), Chl a, Chl b, total carotenes, and total carbohydrate concentrations. Morphological characteristics including height growth, root collar diameter, and terminal shoot growth were also measured. Predawn stem water potential values were generally higher (–0.8 to –1.9 Mpa) than midday values (–1.3 to –2.9 Mpa). Irrigation consistently increased Ψpd and Ψmd compared with non-irrigated treatments. Photosynthetic pigments (Chl a, Chl b, and carotenes) decreased midseason (14 July) and increased toward the end of the season (25 Aug.) in predawn and midday measurements. There was a significant effect (P < 0.05) of drought stress on photosynthetic pigment concentrations in predawn and midday samples in the late-season measurements (25 Aug.). These results were accompanied with a similar significant difference in Fv/Fm between non-irrigated and irrigated trees. We concluded that significant effects observed on photosynthetic pigment concentrations in some of the treatments did not affect carbohydrate concentrations. Exposure of A. fraseri to water stress did not cause a reduction in supply of metabolic carbohydrates; consequently, the decline and mortality in water-stressed plants can only be the result of hydraulic failure caused by xylem cavitation leading to cessation of water flow in tissues, desiccation, and cellular death. Further studies are needed to confirm these preliminary conclusions.

DETERMINATION OF ALUMINUM, CALCIUM, AND MAGNESIUM IN FRASER FIR (ABIES FOLIAGE) FOLIAGE AND SURROUNDING SOIL IN THE SOUTHERN APPALACHIANS

Located at high elevation sites in the Southern Appalachians, the Fraser fir (Abies fraseri) has suffered visible decline in recent years. This study involved the measurement of concentration levels of aluminum, calcium, and magnesium by inductively coupled plasma optical emission spectrometry to determine the contribution of acidic deposition to this decline. Calcium and magnesium are nutrients, and hence one would anticipate relatively high foliar concentrations of these elements in the absence of pollution. Conversely, aluminum is toxic to the trees, and one would expect higher foliar concentrations in polluted locations. Statistical comparisons of the metal concentrations did not demonstrate a causal relationship between the location or elevation of Fraser fir stands. However, compared to previous studies, the foliar concentrations of calcium and magnesium were higher than concentrations previously reported in the 1990s, suggesting pollution controls may have reduced atmospheric deposition.

Fungicide Efficacy in Prevention of Root Rot Incited by Phytophthora cactorum and Phytophthora drechsleri in Fraser Fir Seedlings

The most serious disease problem in fraser fir (Abies fraseri) Christmas tree production is phytophthora root rot (PRR). The efficacies of six fungicide treatments in preventing PRR incited by Phytophthora cactorum and P. drechsleri in 2-year-old fraser fir seedlings were evaluated in 2010 and 2011 in central Pennsylvania. The study examined five fungicide drench treatments [dimethomorph, fosetyl-aluminum (fosetyl-Al), hydrogen dioxide, mefenoxam, propamocarb hydrochloride] and one soil spray treatment (mefenoxam) in raised planting boxes. Dimethomorph applied on 14-day intervals prevented foliar disease symptoms and mortality in fraser fir seedlings exposed to either P. cactorum or P. drechsleri. One-time application of fosetyl-Al or mefenoxam were effective at times in preventing foliar disease symptoms and mortality in fraser fir seedlings exposed to P. drechsleri but were not as effective against P. cactorum.

Succession and disturbance in an endangered red spruce−Fraser fir forest in the southern Appalachian Mountains, North Carolina, USA

Red spruce-Fraser fir forests are geographically limited to high elevations in the Appalachian Mountains (USA) and are considered to be endangered in the USA. We investigated the successional status and radial growth patterns in the heavily disturbed red spruce Picea rubens Sarg. and Fraser fir Abies fraseri (Pursh) Poir. forest of Roan Mountain, Tennessee and North Carolina. This study elucidates the complexity of second-growth red spruce development after logging and disturbances by balsam woolly adelgid Adelges piceae Ratz. We documented precise temporal information of stand age, disturbance regimes, recruitment patterns, and the successional trajectory of the spruce-fir forest community. We used radial growth patterns of red spruce samples to detect the frequency and magnitude of disturbance. Red spruce was the oldest dominant canopy species, although Fraser fir had high recruitment rates over the past 80 yr. Changes in forest structure and species richness coincided with stand-wide disturbance events such as balsam woolly adelgid infestation and widespread early twentieth-century logging. The competitive advantage of Fraser fir over red spruce has resulted in an even-aged Fraser fir-dominant forest that occupies a relatively early stage of successional development. This study provides a 130 yr environmental history to assist land managers in the southern Appalachian Mountains as they develop long-term restoration plans for this unique ecosystem.

Adelges piceae . [Distribution map

Abstract A new distribution map is provided for Adelges piceae (Ratzeburg) [ Dreyfusia piceae ]. Hemiptera: Adelgidae. Hosts: balsam fir ( Abies balsamea ), Fraser fir ( Abies fraseri ), and other Abies spp. Information is given on the geographical distribution in Europe (Albania, Austria, Bosnia-Hercegovina, Bulgaria, Czechoslovakia, Denmark, France, Germany, Greece, Ireland, Italy (Sicily), Lithuania, Macedonia, Netherlands, Norway, Poland, Portugal, Romania, Russia, Serbia, Sweden, Switzerland, UK), Asia (Turkey), North America (Canada (British Columbia, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec), USA (California, Idaho, Maine, New York, North Carolina, Oregon, Tennessee, Virginia, Washington, West Virginia)), South America (Chile).