Elevation-mediated effects of balsam woolly adelgid on southern Appalachian spruce–fir forests

1991 ◽  
Vol 21 (11) ◽  
pp. 1639-1648 ◽  
Author(s):  
V. H. Dale ◽  
R. H. Gardner ◽  
D. L. DeAngelis ◽  
C. C. Eagar ◽  
J. W. Webb
Keyword(s):  
Elevation Gradient ◽  
Ecological Interactions ◽  
Fraser Fir ◽  
Physical Conditions ◽  
Mediated Effects ◽  
Southern Appalachian ◽  
Forest Region ◽  
Balsam Woolly Adelgid ◽  
Survival And Development ◽  
Initial Infestation

The pattern of distribution of endemic Fraser fir (Abiesfraseri (Pursh) Poir.) in the southern Appalachian Mountains is being affected by infestation of the exotic balsam woolly adelgid (BWA) (Adelgespiceae (Ratz.)). BWA kill mature fir trees in about 3–9 years after initial infestation. Prediction of the effects of BWA in a forest region requires an assessment of (i) the population dynamics of the BWA and the fir, (ii) the prevailing physical conditions that affect the spread of BWA, and (iii) the subsequent pattern of fir mortality. This paper predicts the patterns of fir mortality and recovery on an elevation gradient by using a population model with site-specific environmental conditions and ecological interactions. The model shows that temperature range and amplitude, which affect the survival and development rates of BWA, can have an indirect influence on the spatial pattern of living trees. The model results suggest that persistence of both species, with oscillations in numbers over time and space, is probable.

Effect of drought stress and infestation by the balsam woolly adelgid (Homoptera: Adelgidae) on abnormal wood production in Fraser fir

1994 ◽  
Vol 24 (11) ◽  
pp. 2295-2297 ◽  
Author(s):  
Robert G. Hollingsworth ◽  
Fred P. Hain
Keyword(s):  
Drought Stress ◽  
Tree Mortality ◽  
Main Stem ◽  
Diameter Growth ◽  
Wood Production ◽  
Fraser Fir ◽  
Southern Appalachian ◽  
Balsam Woolly Adelgid ◽  
Periods Of Stress ◽  
Wood Increment

Fraser fir (Abiesfraseri (Pursh) Poir.) seedlings were artificially infested with balsam woolly adelgid, Adelgespiceae (Ratz.), then subjected to drought-stress treatments. Infestation caused a distinct swelling in the main stem, caused by the accumulation of abnormal wood (i.e., "rotholz"). As expected, drought stress reduced diameter growth in the main stem. However, the reduction in wood increment caused by drought stress was relatively small for infested seedlings as compared with uninfested seedlings, owing to the production of rotholz. This implies that infested trees expend considerable energy and nutrients for the production of poorly functioning wood even during periods of stress. The implications of this research for interpreting patterns of tree mortality in the southern Appalachian Mountains are discussed.

NMR studies on Fraser fir Abies fraseri (Pursh) Poir. lignins

Holzforschung ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 488-496 ◽  
Author(s):  
Mikhail Yu. Balakshin ◽  
Ewellyn A. Capanema ◽  
Barry Goldfarb ◽  
John Frampton ◽  
John F. Kadla
Keyword(s):  
Quantum Coherence ◽  
Lignin Content ◽  
Lower Amount ◽  
Multiple Quantum ◽  
Normal Wood ◽  
Nmr Studies ◽  
Oh Groups ◽  
Fraser Fir ◽  
Heteronuclear Multiple Quantum Coherence ◽  
Balsam Woolly Adelgid

Abstract The composition of mature, juvenile uninfested and juvenile infested Fraser fir wood (Rotholz) and the structures of lignins isolated from these woods were elucidated to verify differences between juvenile and mature wood and the effect of balsam woolly adelgid (BWA) infestation. Milled wood lignin (MWL) isolated from mature, juvenile and Rotholz wood were comprehensively characterized using heteronuclear multiple quantum coherence (HMQC) and quantitative 13C NMR techniques. The Rotholz wood was found to have ∼13% higher lignin content and more than five-fold the amount of galactans than that of the uninfested wood. Rotholz lignin possesses higher amounts of p-hydroxyphenyl units and aliphatic OH groups and a lower amount of alkyl-O-alkyl linkages and dibenzodioxocin moieties. The degree of condensation of the Rotholz lignin was rather similar to that of normal wood. Only small differences in the structure of mature and juvenile wood components were found.

scholarly journals Well-Aerated Southern Appalachian Forest Soils Demonstrate Significant Potential for Gaseous Nitrogen Loss

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1155
Author(s):  
Peter Baas ◽  
Jennifer D. Knoepp ◽  
Jacqueline E. Mohan
Keyword(s):  
Forest Soils ◽  
Nitrogen Loss ◽  
Elevation Gradient ◽  
High Elevation ◽  
N Cycling ◽  
N Losses ◽  
Northern Hardwood ◽  
Southern Appalachian ◽  
Nitrifier Denitrification ◽  
Gaseous N Losses

Understanding the dominant soil nitrogen (N) cycling processes in southern Appalachian forests is crucial for predicting ecosystem responses to changing N deposition and climate. The role of anaerobic nitrogen cycling processes in well-aerated soils has long been questioned, and recent N cycling research suggests it needs to be re-evaluated. We assessed gross and potential rates of soil N cycling processes, including mineralization, nitrification, denitrification, nitrifier denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) in sites representing a vegetation and elevation gradient in the U.S. Department of Agriculture (USDA) Forest Service Experimental Forest, Coweeta Hydrologic Laboratory in southwestern North Carolina, USA. N cycling processes varied among sites, with gross mineralization and nitrification being greatest in high-elevation northern hardwood forests. Gaseous N losses via nitrifier denitrification were common in all ecosystems but were greatest in northern hardwood. Ecosystem N retention via DNRA (nitrification-produced NO3 reduced to NH4) ranged from 2% to 20% of the total nitrification and was highest in the mixed-oak forest. Our results suggest the potential for gaseous N losses through anaerobic processes (nitrifier denitrification) are prevalent in well-aerated forest soils and may play a key role in ecosystem N cycling.

scholarly journals Oligodendrocytes Are Targets of HIV-1 Tat: NMDA and AMPA Receptor-Mediated Effects on Survival and Development

2015 ◽  
Vol 35 (32) ◽  
pp. 11384-11398 ◽  
Author(s):  
S. Zou ◽  
B. Fuss ◽  
S. Fitting ◽  
Y. K. Hahn ◽  
K. F. Hauser ◽  
...  
Keyword(s):  
Ampa Receptor ◽  
Mediated Effects ◽  
Survival And Development ◽  
Hiv 1

Size- and age-class distributions of Fraser fir following balsam woolly adelgid infestation

2000 ◽  
Vol 30 (6) ◽  
pp. 948-957 ◽  
Author(s):  
George F Smith ◽  
N S Nicholas
Keyword(s):  
Permanent Plots ◽  
Seedling Mortality ◽  
Regeneration Potential ◽  
Abies Fraseri ◽  
Great Smoky Mountains ◽  
Fraser Fir ◽  
Advance Regeneration ◽  
Size And Age Structure ◽  
Smoky Mountains ◽  
Balsam Woolly Adelgid

Fraser fir (Abies fraseri (Pursh) Poir.) has suffered catastrophic mortality throughout most of its native range from an exotic insect, the balsam woolly adelgid (Adelges piceae Ratz.). To assess the regeneration potential and viability of fir populations, overstory and understory Fraser fir size and age structure were analyzed. The data were collected from thirty-six 400-m2 permanent plots, stratified into four stand canopy composition types, established near the summits of five mountains in the Great Smoky Mountains. We found that, where canopy mortality was severe, fir advance regeneration was re-entering the overstory. In seriously impacted stands, mortality of large fir and increased recruitment have produced distributions characterized by few large fir and relatively high densities of small fir. Densities of 0- to 10-year-old fir seedlings and fir seedlings [Formula: see text]0.25 m tall were much lower in stands dominated by dead fir than in mostly intact fir stands. While the lack of reproducing adults appears to be the main cause, competition with invasive species and higher seedling mortality from environmental factors probably contribute. These results lead to a hypothesis that Fraser fir will undergo a regeneration-mortality cycle with a decrease in the numbers of each successive generation.

Physico-Chemical Responses of Fraser Fir Induced by Balsam Woolly Adelgid (Homoptera: Adelgidae) Infestation

2016 ◽  
Vol 51 (1) ◽  
pp. 94-97
Author(s):  
Erin C. Mester ◽  
Lucian Lucia ◽  
John Frampton ◽  
Fred P. Hain
Keyword(s):  
Fraser Fir ◽  
Physico Chemical ◽  
Balsam Woolly Adelgid

The Effect of Adelgid-Altered Wood On Sapwood Conductance of Fraser Fir Christmas Trees

IAWA Journal ◽  
1991 ◽  
Vol 12 (3) ◽  
pp. 235-239 ◽  
Author(s):  
Robert G. Hollingsworth ◽  
Udo Blum ◽  
Fred P. Hain
Keyword(s):  
Water Stress ◽  
Flow Rate ◽  
Wood Production ◽  
Flow Rates ◽  
Fraser Fir ◽  
Christmas Trees ◽  
Balsam Woolly Adelgid

Potential sapwood flow rates were measured for Fraser fir sterns that previously had been infested by the balsam woolly adelgid. The amount of abnormal wood produced during infestation was inversely related to the flow rate and linearly related to the amount of heartwood area. These results support the hypothesis that abnormal wood production associated with adelgid infestation can lead to water stress in the crowns of infested trees. The data also suggest that adelgid infestation accelerates the formation of heartwood.

scholarly journals Recovery trends and predictions of Fraser fir (Abies fraseri) dynamics in the Southern Appalachian Mountains

2017 ◽  
Vol 47 (1) ◽  
pp. 125-133 ◽  
Author(s):  
S. Douglas Kaylor ◽  
M. Joseph Hughes ◽  
Jennifer A. Franklin
Keyword(s):  
Census Data ◽  
Population Data ◽  
Abies Fraseri ◽  
Great Smoky Mountains ◽  
Fraser Fir ◽  
Balsam Woolly Adelgid ◽  
Hierarchical Bayesian Inference ◽  
Local Extirpation ◽  
Term Monitoring

The endemic Fraser fir (Abies fraseri (Pursh) Poir.) is found in only seven montane regions in the southern Appalachians above ca. 1500 m elevation. Due to widespread insect-caused mortality from the invasive balsam woolly adelgid (Adelges piceae Ratzeburg), as well as possible impacts from climate change and atmospheric pollution, the future of Fraser fir populations remains uncertain. Long-term monitoring programs have been in place since the 1980s, and here we present the first predictive population models for endemic Fraser fir populations using the inventory data from Great Smoky Mountains National Park, which contains 74% of extant Fraser fir forests. Using two kinds of population data (understory density counts and overstory census data), we model Fraser fir population dynamics on five different mountaintops as a stage-structured matrix model with transition parameters estimated using hierarchical Bayesian inference. We predict robust recovery over the next several decades for some Fraser fir populations, particularly where mature overstory fir has persisted throughout the last two decades, and continued decline for populations at the lowest elevations. Fraser fir densities are already low at these lower elevations, suggesting that this population is vulnerable to local extirpation.

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