Download or read book Effects of Hemlock Woolly Adelgid on Ectomycorrhizal Fungi Associated with Tsuga Canadensis Eastern Hemlock in Central New York written by Matthew T. Amoia and published by . This book was released on 2017 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

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.

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.

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.

Download or read book A Quantitative Study of Nonstructural Carbohydrates in Eastern Hemlock Tsuga Canadensis and the Effects of Hemlock Woolly Adelgid Adelgis Tsugae and Elongate Hemlock Scale Fiorinia Externa Ferris Infestation written by Lora Schwartzberg and published by . This book was released on 2010 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

Download or read book Xylem Transport Models Optimize Effectiveness of Systemic Insecticide Applications for Controlling Hemlock Woolly Adelgid Adelges Tsugae written by Chelcy R. Ford and published by . This book was released on 2010 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is causing widespread decline and mortality of eastern hemlock trees (Tsuga canadensis (L.) Carr.). Stem injection of insecticide is widely used as a control measure, but its effectiveness depends on individual tree hydraulic characteristics. Recent work has shown that eastern hemlock daily water use is exponentially related to tree diameter, with smaller-diameter trees using significantly less water than largerdiameter trees. In this study we modeled daily water use for 20 eastern hemlock trees across a range of diameters. Based on expected daily water use and, thus, potential xylem transport of insecticide, we applied a dosage estimated to achieve a lethal and uniform xylem sap concentration of imidacloprid to half the trees (xylem transport treatment), and treated the remaining half based on the manufacturerrecommended dosage (MFR treatment), which is a linear function of tree diameter. At 4 and 56 weeks after treatment, we assessed all trees for the presence or absence of new shoot growth and live HWA population density. We found that both treatment dosages significantly reduced live HWA populations; however, 4 weeks after treatment, live HWA population density was 32 percent lower (LSMEANS) on xylem transport treatment trees compared with MFR treatment trees (treatment by time interaction, P = 0.006). Both treatment dosages also significantly increased the proportion of new shoot growth; however, over time xylem transport treatment trees had a significantly greater increase in new shoot production compared with MFR treatment trees. We conclude that dosages based on a xylem transport model not only significantly improved tree health more than the trees receiving the current recommended dosage, but also caused greater reductions in the live HWA population. Improving treatment dosages would reduce treatment cost, nontargeted effects, and would allow land managers to treat a greater number of trees.

Download or read book Impact of hemlock woolly adelgid on eastern hemlock stands in the Black Forest Cornwall New York written by Aaron Kimple and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technology Transfer Hemlock Woolly Adelgid written by S. M. Salom and published by . This book was released on 1996 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

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.

Download or read book Density dependent Survival of Hemlock Woolly Adelgid Life Stages written by Elizabeth M. Sussky and published by . This book was released on 2013 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: To investigate the density-dependent factors that may be partly responsible for the apparent stability of hemlock woolly adelgid (HWA; Adelges tsugae Annand) populations in central New England, we infested 64 eastern hemlock (Tsuga canadensis Carrière) trees with varying densities of HWA sistens ovisacs in a typical eastern hemlock forest in western Massachusetts. We subsequently documented HWA density, fecundity, and the amount of new growth on experimental trees over two consecutive years. We used a 2 x 2 randomized block design using previously and newly infested hemlocks divided into 1 m tall saplings and branches of mature trees. There was a density-dependent decline in the survival and fecundity of HWA in both the spring and winter generations. This response was a function of both previous infestation by HWA and current years crawler density in the spring generation. Additionally, the production of sexuparae in the spring generation played a key role in the overall density-dependent survival of HWA, suggesting that sexuparae production is strongly linked to developing crawler density. In Chapter 2, varying densities of HWA were manipulated on 16 previously uninfested eastern hemlocks in an open field plantation. In contrast to HWA populations in our forest experiment, there was no evidence of density-dependent survival on a tree-wide basis in the plantation in the springtime progrediens generation. However, there were comparable density-dependent survival of settled crawlers and sexuparae production when samples of the population were examined from branches with high density. Plantation hemlocks had 9.3 times more foliage and ten times lower HWA densities per cm than forest hemlocks. Despite the lack of density-dependence in the progrediens generation of this study, HWA populations of the subsequent sistens generation went extinct on 13 out of the 16 trees. These results show that density-dependent processes may only exist when HWA density/cm reaches a certain threshold, and that high mortality may occur during the late-summer aestivation phase at densities below this threshold, perhaps due to high summertime temperatures in HWAs sistens generation. These results may help explain the slow process of HWA establishment in our region.

Download or read book Spatial Temporal and Tri trophic Distribution of Imidacloprid Olefin and 5 hydroxy and Their Effect on Hemlock Woolly Adelgid Adelges Tsugae Annand Hemiptera Adelgidae written by Carla Irene Coots and published by . This book was released on 2012 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) (HWA), has occurred throughout the eastern United States. Imidacloprid, a systemic insecticide, is used to control hemlock woolly adelgid. The metabolism of imidacloprid in eastern hemlock produces two metabolites of toxicological interest, olefin and 5-hydroxy. The objectives of this study were to 1.) determine the distribution and persistence of the metabolites in eastern hemlock in the southern Appalachians, 2.) their effect on hemlock woolly adelgid mortality, 3.) assess the tri-trophic movement of these compounds, 4.) evaluate the effects of hemlock woolly adelgid infestation levels on water stress, and 5.) assess the use of near-infrared spectroscopy for predicting imidacloprid concentrations in needle tissue. Imidacloprid and 5-hydroxy concentrations in sap was highest at 12 months post-treatment and in twig and needle tissue was highest at 15 months post-treatment. Imidacloprid was detected through month 36 post-treatment and 5-hydroxy was detected through month 15 post-treatment. Olefin concentrations progressively increased in both sap and twig and needle tissue through month 36 post-treatment. Concentrations of imidacloprid were highest in the bottom stratum of the canopy and lowest in the top stratum. Concentrations of olefin and 5-hydroxy were highest in the top stratum and lowest in the bottom stratum. A significant relationship was found between imidacloprid concentrations > 158 ppb and olefin concentrations > 7 ppb and hemlock woolly adelgid mortality greater than 80% in field studies. In dose-response tests imidacloprid concentrations greater than 131 ppb and olefin concentration greater than 7 ppb were associated with high levels of hemlock woolly adelgid mortality (> 80%). Tri-trophic movement of imidacloprid and olefin was documented through 2 years post-treatment. The highest level of water stress was found in those trees with hemlock woolly adelgid infestation levels greater than 75%. The lowest level of water stress was found in those trees with less than 25% hemlock woolly adelgid infestation levels. Near-infrared spectroscopy results indicate that it can be used to predict concentrations of imidacloprid in needle tissue.

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:

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

Download or read book Effects of Eastern Hemlock Tsuga Canadensis Decline on Forest Floor Characteristics and Macrofungal Communities at Two Sites in Western Massachusetts written by Aliza M. Boles Fassler and published by . This book was released on 2017 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: