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Showing 1 to 20 of 41 for “"Tsuga"”.
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The effect of forest fertilization on the ectomycorrhizae of western hemlock (tsuga heterophylla)
… composed almost exclusively of western hemlock [Tsuga heterophylla (Rafn.)Sarg.], located in the Mount Seymour Demonstration Forest, North Vancouver, British Columbia. Changes in the abundance of 10mycorrhizal types (Cenococcum geophilum Fr., Lactarius scrobiculatus (Scop.) ex. Fr., Mycelium …
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A Phylogenetic Analysis of Species Relationships in Hemlocks, the Genus <em>Tsuga</em> (Pinaceae).
<p>The genus <em>Tsuga</em> is comprised of eight extant species found in North America and East Asia and four species represented by fossils from Europe and Japan. This study presents the first phylogenetic analysis based on structural, biochemical, and molecular sequence data. Characters obtained …
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Development and properties of tracheids and their cell wall layers in eastern hemlock (Tsuga canadensis L.)
Changes in anatomical, physical and chemical properties within developing and one-year-old increments were investigated in a 52-year old eastern hemlock tree, felled in the latter part of July, 1968. Based on available previous knowledge, the zones of xylem maturation stages were determined by the …
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Fitness and Physiology of the Hemlock Woolly Adelgid, Adelges tsugae, in Relation to the Health of the Eastern Hemlock, Tsuga canadensis
The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Sternorrhyncha: Adelgidae) is a small invasive insect that frequently causes hemlock (Tsugae spp.) mortality in the eastern United States. Studies have shown that once healthy hemlocks become infested by the adelgid, nutrients are …
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Impact of predation by Laricobius nigrinus (Coleoptera: Derodontidae) and Leucotaraxis spp. (Diptera: Chamaemyiidae) on Adelges tsugae (Hemiptera: Adelgidae) and Tsuga canadensis (Pinales: Pinaceae) tree health
The hemlock woolly adelgid (HWA), Adelges tsugae Annand, (Hemiptera: Adelgidae) is an invasive species in the eastern United States and Canada. This scale-like insect feeds on the xylem ray parenchyma cells of eastern hemlock, Tsuga canadensis (L.) Carrière, (Pinales: Pinaceae) and Carolina …
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The Role of Fire in Montane Forest Environments in the Willamette National Forest, Oregon
… the dominant vegetation, along with <em>Pseudotsuga </em>and <em>Alnus</em>, suggesting that an open-canopy conifer forest developed soon after the area was glacier free. Fire frequency increased during the early Holocene. Warmer and drier conditions are reflected in the herbaceous vegetation, …
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Biological Studies and Evaluation of Scymnus Coniferarum, a Predator of Hemlock Woolly Adelgid from Western North America
The hemlock woolly adelgid (HWA), Adelges tsugae Annand, is an invasive pest of eastern hemlock, Tsuga canadensis (L.) Carriere and Carolina hemlock Tsuga caroliniana Englem. in the eastern United States. A newly reported beetle predator for HWA, Scymnus (Pullus) coniferarum Crotch (Coleoptera: …
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High-Resolution Record of Vegetation and Climate Change During the Holocene in Southwestern Québec
… variability during the Holocene. The well known Tsuga decline at Lac Noir lasted 500 years starting at 5.5 ka and it took 1 460 years for hemlock to recover. The highest frequency of fire activity occurred during the early Holocene, and the lowest in the mid-Holocene. The late Holocene saw an …
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Studies on the Subterranean Activity of Laricobius spp. (Coleoptera: Derodontidae) using 3D X-ray Analysis and Three Imidacloprid Soil Application Techniques
The hemlock woolly adelgid (HWA) Adelges tsugae (Annand) (Hemiptera: Adelgidae), has spread throughout most of the range of eastern hemlocks, Tsuga canadensis (L.) and the entire range of Carolina hemlocks, Tsuga caroliniana (Engelman) in eastern North America. Forest managers often implement an …
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Laboratory rearing, establishment, subterranean survivorship, and thermal requirements of Laricobius spp. (Coleoptera: Derodontidae), biological control agents released for Adelges tsugae (Hemiptera: Adelgidae)
The hemlock woolly adelgid (HWA) (Adelges tsugae [Annand]) (Hemiptera: Adelgidae) is a non-native lethal pest to eastern hemlock (Tsuga canadensis [L.] (Pinales: Pinaceae), and Carolina hemlock (Tsuga caroliniana [Engelmann]) (Pinales: Pinaceae). In the early 2000's, a robust biological control …
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In-Stream Hemlock Twig Breakdown and Effects of Reach-Scale Twig Additions on Appalachian Headwater Streams
Eastern hemlock (Tsuga canadensis) is a prominent tree in the forests of eastern North America, where it commonly grows along headwater streams. It is experiencing widespread mortality due to infestations of an introduced insect, the hemlock woolly adelgid (Adelges tsugae). Eliminations of tree …
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Release-Recovery in the Field and Reproductive Success in the Lab of Laricobius osakensis (Coleopera: Derodontidae) a Biological Control Agent for the Hemlock Woolly Adelgid, Adelges tsugae
The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae) is a small, non-native insect that feeds on hemlock (Tsuga spp.) species native to the eastern United States. One biological control agent, Laricobius osakensis, shows promise due to its voracious feeding on and …
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The Inhibitory Effect of Rhododendron maximum L. (Ericaceae) Thickets on Mycorrhizal Colonization of Canopy Tree Seedlings
… of red oak (Quercus rubra) and hemlock (Tsuga canadensis) were harvested at the end of the first and second growing seasons. Litter manipulation had no effect on total mycorrhizal colonization. Mycorrhizal colonization and ramification index (# mycorrhizae cm-1) were depressed and …
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Eastern Hemlock Needle Physiology as Impacted by Hemlock Wooly Adelgid and Treatment with Imidacloprid
Eastern hemlock (Tsuga canadensis [L.] Carr.) is a foundation species that occupies a unique niche in forest ecosystems and which often forms pure stands throughout the eastern United States. Throughout the last half of a century, widespread mortality of T. canadensis had been occurring with the …
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The influence of salal on planted hemlock and cedar saplings on northern Vancouver Island
… 4-year-old conifer performance (western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western red cedar (Thujaplicata Donn ex D. Don)) and salal (Gaultheria shallon Pursh) leaf area index, and the effect of salal leaf area index on the 2-year growth increment of western red cedar andwestern …
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Radial growth response of eastern hemlock to infestation of hemlock woolly adelgid
Hemlock woolly adelgid (Adelges tsugae Annand) is causing defoliation and mortality of eastern hemlock (Tsuga canadensis (L.) Carrière) in the eastern United States. The objectives of this study were to quantify changes in tree-ring width and wood anatomy for trees that survived adelgid …
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Differential Canopy Leaf Flushing and Site Nitrogen Status Facilitate Invasive Species Establishment in Temperate Deciduous Forest Understories
… (black locust), and <em>Pinus </em>spp<em>./Tsuga canadensis</em> (pine/hemlock). Measures of understory light availability post-leaf expansion were significantly higher under quaking aspen than other canopies with the exception of black locust and white ash. Significant differences in …
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Forest Dynamics Of Two Multi-Aged Hemlock-Mixed Mesophytic Forests In The Northern Cumberland Plateau, Kentucky
<p>Tsuga canadensis (eastern hemlock) is a foundation species that performs a unique ecological role within the Appalachian mixed mesophytic forest of the eastern United States. However, the non-native hemlock woolly adelgid (HWA; Adelges tsugae Annand), a novel invasive colonizer, is significantly …
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Soil Respiration and Related Abiotic and Remotely Sensed Variables in Different Overstories and Understories in a High Elevation Southern Appalachian Forest
… under consideration were an eastern hemlock (Tsuga canadensis L. Carriere) dominated overstory, a hardwood overstory with little to no understory, a mountain laurel (Kalmia latifolia L.) dominated understory, and a cinnamon fern (Osmundastrum cinnamomeum (L.) C.Presl) dominated understory. …
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