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Impacts Of The Hemlock Woolly Adelgid Adelges Tsugae On Headwater Stream Wood Loads In The Southern Appalachian Mountains
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Book Synopsis Impacts of the Hemlock Woolly Adelgid (Adelges Tsugae) on Headwater Stream Wood Loads in the Southern Appalachian Mountains by : Burke Alexander McDade
Download or read book Impacts of the Hemlock Woolly Adelgid (Adelges Tsugae) on Headwater Stream Wood Loads in the Southern Appalachian Mountains written by Burke Alexander McDade and published by . This book was released on 2018 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Aquatic Effects of the Hemlock Woolly Adelgid (Adelges Tsugae) on Headwater Streams in South-central Pennsylvania by : Alicia R. Helfrick
Download or read book The Aquatic Effects of the Hemlock Woolly Adelgid (Adelges Tsugae) on Headwater Streams in South-central Pennsylvania written by Alicia R. Helfrick and published by . This book was released on 2015 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Riparian Ecosystem Response to Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality in the Great Smoky Mountains National Park, USA by : Misty Dawn Huddleston
Download or read book Riparian Ecosystem Response to Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality in the Great Smoky Mountains National Park, USA written by Misty Dawn Huddleston and published by . This book was released on 2011 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: An invasive insect, hemlock woolly adelgid (HWA), has initiated widespread hemlock decline and mortality in the Great Smoky Mountains National Park (GSMNP). Riparian hemlock mortality impacts on vegetative and aquatic systems of first-order, headwater streams were evaluated. Reference sites for this study were representative of the best available conditions within the GSMNP, with initial stages of HWA presence. Impacted sites were defined as areas with over 90 percent hemlock mortality. Impacted streams had decreased canopy coverage and increased light availability. Residual red maple, yellow birch, and sweet birch capitalized on the loss of hemlock, with increases in relative basal area and species importance values. Rosebay rhododendron responded with increased density and height at impacted sites, thereby preventing woody regeneration. Since long-term regeneration and post-mortality canopy recruitment are limited, alterations of vegetative composition and structure in the stream riparian zone are expected. A seasonal assessment (Sept. 2009 -- March 2010) of aquatic impacts revealed increased diurnal variation in stream temperature and exhibited cooler temperatures during the colder months than reference streams. Impacted streams exhibited greater amounts and larger size classes of large woody debris (LWD). Higher concentrations for several nutrients, including silicon, sodium, potassium, magnesium, chlorine, and copper were detected in impacted streams than detected in reference streams. Impacted streams were characterized by higher pH and increased acid neutralization capacity, while reference streams exhibited nitrate concentrations three times higher than impacted stream concentrations. Reference streams were experiencing the initial stage of HWA-induced defoliations, increasing stream nitrate concentrations, while impacted sites had levels suggesting nitrate concentrations have returned to pre-infestation levels. A seasonal assessment of macroinvertebrates found species diversity, abundance, and taxa richness were not affected by hemlock mortality. Impacted streams had a lower density of Chironomidae and Ephemeroptera when compared to reference streams, while Pleuroceridae snails were virtually eliminated at impacted stream sites. Reference streams were dominated by the collector/filter functional feeding group (FFG), while impacted streams were dominated by the scraper FFG. Hemlock mortality induced by the presence of HWA has resulted in short-term impacts to vegetative and aquatic dynamics in stream riparian areas of the Great Smoky Mountain National Park.
Book Synopsis Spatial Tools for Managing the Hemlock Woolly Adelgid in the Southern Appalachians by :
Download or read book Spatial Tools for Managing the Hemlock Woolly Adelgid in the Southern Appalachians written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Native to Asia, the hemlock woolly adelgid (Adelges tsugae) has recently spread into parts of the southern Appalachian region. This insect pest attacks both native hemlock species (Tsuga canadensis and T. caroliniana), has no natural enemies, and can kill hemlock trees within just a few years. While biological control displays promise for combating the pest, such counter-measures are significantly hampered because neither adelgid nor hemlock distribution patterns have been detailed explicitly. We developed a spatial management system to better target control efforts. The system has two components: (1) a protocol for mapping hemlock stands, and (2) a technique to map areas at risk of imminent hemlock woolly adelgid infestation. To map hemlock stands, we utilized topographically normalized satellite imagery from Great Smoky Mountains National Park. Because hemlocks are difficult to distinguish using just satellite data, we constructed a decision tree classifier that supplemented the imagery with a suite of topographic, environmental, and proximity variables. We then implemented the classifier in a geographic information system and generated hemlock distribution maps. Our final decision tree had 27 terminal nodes and nine variables, with elevation, image band ratios, topographic relative moisture index, and distance to the closest stream among the most important variables. Accuracy assessment--based on field data and aerial photos--of the maps resulting from this tree yielded an overall thematic accuracy of 90% for one study area and 75% accuracy in capturing hemlocks in a second study area. To map areas at risk, we combined known first-year infestation locations from Great Smoky Mountains National Park and the Blue Ridge Parkway with points from uninfested hemlock stands, recording a suite of environmental variables for each point. We applied four different techniques (discriminant analysis, k-nearest neighbor, logistic regression, and decision tree) to gene.
Book Synopsis Large Wood Dynamics in Central Appalachian Hemlock Headwater Ravines by : Paul Joseph Soltesz
Download or read book Large Wood Dynamics in Central Appalachian Hemlock Headwater Ravines written by Paul Joseph Soltesz and published by . This book was released on 2014 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large wood (LW) is a critical component of forested mountain headwater streams that significantly contributes to geomorphic and ecological processes including channel structure, sediment and nutrient dynamics, flow regimes, and habitat formation for fish and aquatic macroinvertebrates. The character of LW is a function of valley recruitment processes that influence LW entering the channel and instream retention processes that influence LW transport through the channel reach. In the central Appalachian Mountains, US, LW dynamics in eastern hemlock-dominated ravines may change due to the invasive insect Hemlock Wooly Adelgid (HWA). However, quantitative LW studies are lacking for this region, yet are necessary for effective management of ecosystem health and processes regarding projected HWA-associated change. We examined LW dynamics across central Appalachian headwater streams (drainage area 20 km2) to identify: 1) the current state of LW loading, 2) the environmental factors that influence LW loading, 3) potential signs of HWA impact on LW dynamics, and 4) functional grouping patterns of LW pieces in these systems. A field study was conducted in 24 streams across southeastern Ohio, West Virginia, and western Virginia that represent a gradient of HWA infestation from 0 (uninfested) to 23 years. At each site, channel morphology, in-stream wood load, and wood recruitment potential were recorded. Mean wood density was 36 pieces/100m ± 21 and mean wood volume was 5.6 m3/100m ± 3.5. Most pieces were less than bankfull width suggesting high transportability, but large pieces (10m) contributed significantly to wood volume, jam formation (>3 LW pieces touching), and geomorphic function. Central Appalachian LW loading was on the lower end of mountain headwater streams reported elsewhere in the world, although comparable to similar stream types in the northeastern US. A mixture of recruitment and retention processes influenced LW dynamics, but channel retention processes better explained LW jam dynamics. Specifically, higher LW load was associated with lower forest basal area, smaller channel dimensions, and lower hydraulic driving forces, which is consistent with other studies. We did not detect a significant influence of HWA infestation even in moderately advanced infestation (e.g., ~20 years) on LW load, which may reflect a lag period between tree mortality, toppling, and LW load. Pieces clustered in three functional groups of: 1) larger, stable pieces that store sediment, stabilize the bank, and create pools, 2) relatively stable pieces that deflect flow and dissipate energy, and 3) smaller pieces associated with flow deflection and energy dissipation composed of mixed stability. This study provides quantitative information on LW dynamics in the central Appalachian region prior to expected environmental change associated with HWA. This information may aid land managers in regulating LW loads and environmental processes influenced by LW including sediment dynamics, aquatic habitat creation, and flow regimes.
Book Synopsis Eastern Hemlock Forests by : Jeffrey S. Ward
Download or read book Eastern Hemlock Forests written by Jeffrey S. Ward and published by . This book was released on 2004 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Impacts of Hemlock Woolly Adelgid on Tsuga Canadensis Forest Communities in Great Smoky Mountains National Park, USA by : Kurt J. Krapfl
Download or read book Impacts of Hemlock Woolly Adelgid on Tsuga Canadensis Forest Communities in Great Smoky Mountains National Park, USA written by Kurt J. Krapfl and published by . This book was released on 2010 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tsuga canadensis (L.) Carr. (eastern hemlock), a long lived and shade tolerant coniferous tree species native to eastern North America, is currently threatened by the hemlock woolly adelgid ( Adelges tsugae Annand, HWA). This exotic, invasive insect poses a serious threat to T. canadensis stands throughout their native range. The loss of this unique tree species is often coupled with numerous ecological consequences. HWA-induced mortality has exceeded 95% in some forest types, and will likely continue to decimate T. canadensis populations in the coming years. Shortly after HWA was found in Great Smoky Mountains National Park (GSMNP), long-term monitoring plots were established across a gradient of T. canadensis associated forest communities to monitor HWA impacts and stand decline. Our objectives were to (1) determine how T. canadensis populations have changed in conjunction with HWA infestation, and (2) document how HWA has affected vegetative community dynamics following five to six years of infestation in GSMNP.
Book Synopsis The Effect of Hemlock Woolly Adelgid Infestation on Water Relations of Carolina and Eastern Hemlock by :
Download or read book The Effect of Hemlock Woolly Adelgid Infestation on Water Relations of Carolina and Eastern Hemlock written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In North America, hemlock woolly adelgid (HWA; Adelges tsugae Annand) is an exotic insect pest from Asia that is causing severe decimation of native eastern hemlock (Tsuga canadensis (L.) Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). Extensive research has been committed to the ecological impacts and potential control measures of HWA, but the exact physiological mechanisms that cause tree decline and mortality are not known. Eastern and Carolina hemlock may be reacting to infestation in a manner similar to the response of Fraser fir (Abies fraseri (Pursh.) Poir.) to infestation by balsam woolly adelgid (BWA; Adelges picea Ratz.). It is known that Fraser fir produces abnormal xylem in response to BWA feeding. This abnormal xylem obstructs water movement within the trees, causing Fraser fir to die of water-stress. In this study, water relations within 15 eastern and Carolina hemlock were evaluated to determine if infestation by HWA was causing water-stress. Water potential, carbon-13 isotope ratio, stem conductivity, and stomatal conductance measurements were conducted on samples derived from those trees. In addition, branch samples were analyzed for possible wood anatomy alterations as a result of infestation. Pre-dawn branch water potential (Î ̈) measurements were more negative in infested hemlock than in non-infested trees. Carbon isotope ratios (normalized Î ́13C vs. VPDB) of the branches were more positive for infested trees, while stomatal conductance (gs) was lower in infested trees. These results indicate that infested eastern and Carolina hemlock are experiencing drought-like symptoms. Wood anatomy of the branches provided evidence that infested hemlocks are experiencing abnormal wood production in the xylem.
Book Synopsis Impact of the Invasive Hemlock Woolly Adelgid on Headwater Stream Aquatic and Ground-dwelling Invertebrate Communities by : Joshua Keith Adkins
Download or read book Impact of the Invasive Hemlock Woolly Adelgid on Headwater Stream Aquatic and Ground-dwelling Invertebrate Communities written by Joshua Keith Adkins and published by . This book was released on 2012 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Preparing for the Onset of Hemlock Mortality in Great Smoky Mountains National Park by :
Download or read book Preparing for the Onset of Hemlock Mortality in Great Smoky Mountains National Park written by and published by . This book was released on 2006 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently the Hemlock Woolly Adelgid (Adelges tsuga) is spreading across forests in eastern North America, causing the decline and mortality of the eastern hemlock and the Carolina hemlock. Investigation into the impact of hemlock mortality on ecosystem processes has only recently begun and is not yet fully understood. The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) could reasonably be expected to result in significant alterations to stream environments. The goal of this study was to assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP. I paired hardwood-and hemlock-dominated streams that were similar in topography, geology, land use, and disturbance history using Geographic Information Systems (GIS) analysis and statistical techniques. I then monitored each stream pair for water temperature, nitrate concentrations, pH, and discharge over eleven months. I found that differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone; the presence of hemlock or hardwood riparian forest does not appear to exert a consistently dominant signal on measured conditions of headwater streams in GSMNP. The variability in the results suggests that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than differences between hemlock and hardwood canopies. For example, Rhododendron was found to reduce light levels reaching the forest floor and streambeds in both hemlock- and hardwood- dominated forest stands. Evidence from recent peer-reviewed literature suggests that short-term stream condition impacts from forest disturbances can be severe. However, research also indicates that conditions can return to pre-disturbance levels within five to ten years. In GSMNP, the return to long-term stability of stream conditions after hemlock mortality will depend on the type of replacement species and how quickly the replacement species can establish in disturbed sites. There is evidence that deciduous hardwood species are most likely to replace hemlock. The results of this study suggest that hemlock and hardwood stream conditions are similar in GSMNP. Therefore, if hardwood species are able to replace hemlock in GSMNP and streams are able to recover from short term impacts, the long term impacts from hemlock mortality on stream conditions will be minimal. However, the presence of Rhododendron in riparian hemlock forests in GSMNP may prevent hardwood species from effectively replacing hemlock, which could hinder the return to long-term stability.
Book Synopsis Modeling The Effects Of The Hemlock Woolly Adelgid On Carbon Storage In Northern New England Forests by : Jeffrey John Krebs
Download or read book Modeling The Effects Of The Hemlock Woolly Adelgid On Carbon Storage In Northern New England Forests written by Jeffrey John Krebs and published by . This book was released on 2014 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is an invasive insect that threatens to eradicate native eastern hemlock (Tsuga canadensis (L.) Carr.) across the eastern United States. In southern New England and southern Appalachian forests, HWA-induced hemlock mortality has impacted carbon (C) flux by altering stand age, litter composition, species composition, and coarse woody debris levels. However, no one has examined how total C storage and sequestration may be impacted by these changes. Further, while projections are that HWA will ultimately infest hemlock across its entire geographic range, the majority of studies have been limited to southern New England and Appalachian forests where HWA infestation has been ongoing. To address these gaps, we examined how HWA might alter C dynamics in northern New England forests using the Forest Vegetation Simulator (FVS) and Forest Inventory Analysis (FIA) data to model C storage and successional pathways under three different scenarios: preemptive harvesting of hemlock, HWA-induced hemlock mortality, and a control mimicking natural stand development absent of disturbance. Our 150 year simulation showed that, while all treatments differed significantly in C storage in the short term, there was no significant difference in total C stocks between HWA infestation and presalvage treatments by the 75th year. Compared to the control, both simulated treatments resulted in a significant decrease in total C storage, with greater impacts on stands with higher hemlock densities. However, net C losses over the 150 year simulation were significantly higher for the presalvage scenario, indicating that allowing HWA infestation to progress naturally through a stand may result in the least impact to long-term C sequestration for the region's forests.
Book Synopsis Standardized Sampling for Detection and Monitoring of Hemlock Woolly Adelgid in Eastern Hemlock Forests by : Scott Costa
Download or read book Standardized Sampling for Detection and Monitoring of Hemlock Woolly Adelgid in Eastern Hemlock Forests written by Scott Costa and published by . This book was released on 2006 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis City promenade Deventer, elke stap waard by :
Download or read book City promenade Deventer, elke stap waard written by and published by . This book was released on 1976 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Prioritizing Eastern Hemlock (Tsuga Canadensis) for Secondary Imidacloprid Treatment Against the Invasive Hemlock Woolly Adelgid (Adelges Tsugae) in Shenandoah National Park by :
Download or read book Prioritizing Eastern Hemlock (Tsuga Canadensis) for Secondary Imidacloprid Treatment Against the Invasive Hemlock Woolly Adelgid (Adelges Tsugae) in Shenandoah National Park written by and published by . This book was released on 2016 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shenandoah National Park (SNP) contains over 20,000 eastern hemlocks (Tsuga canadensis); a foundation species in the southern Appalachian Mountains. Hemlock is shade-tolerant and retains a dense needle canopy year-round, creating a unique microclimate providing habitat for many species. The decline in eastern hemlock from hemlock woolly adelgid (Adelges tsugae; HWA) infestation has negative implications for the overall function of forest ecosystems. The effect of slope aspect and time since imidacloprid insecticide treatment on crown health change and diameter growth of eastern hemlock in SNP was quantified. Data was compared from hemlock trees located on southeastern (SE) and northwestern (NW) aspects at sites that were either treated two, five or eight years ago. Trees at control sites received no treatment. Change in crown health was significantly affected by aspect and time since treatment (p
Book Synopsis Predicting Infestations of Hemlock Woolly Adelgid (Adelges Tsugae) in Great Smoky Mountains National Park, Tennessee/North Carolina, USA by : Snider Scott F.
Download or read book Predicting Infestations of Hemlock Woolly Adelgid (Adelges Tsugae) in Great Smoky Mountains National Park, Tennessee/North Carolina, USA written by Snider Scott F. and published by . This book was released on 2004 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Biological Control of Hemlock Woolly Adelgid by :
Download or read book Biological Control of Hemlock Woolly Adelgid written by and published by . This book was released on 2004 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Effect of Hemlock Woolly Adelgid Infestation on Water Relations of Carolina and Eastern Hemlock by : Laura Newman Walker-Lane
Download or read book The Effect of Hemlock Woolly Adelgid Infestation on Water Relations of Carolina and Eastern Hemlock written by Laura Newman Walker-Lane and published by . This book was released on 2009 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: introduced pest species, host response, tsuga canadensis, tsuga caroliniana, adelges tsugae.
