Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"snag"”.
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Understory Composition, Seedling Growth, and Snag Frequency Across a Water-Limited Forest Landscape
… of my fourth chapter was to determine how snag (standing dead tree) distribution is affected by individual- and stand-level biotic and abiotic variables. I used an unmanned aerial vehicle to collect images of forest canopies and determine the position and characteristics of individual live …
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Experimental study of an avian cavity-nesting community: nest webs, nesting ecology, and interspecific interactions
… within this community. In chapter 3, I describe snag densities and nest-site selection of the cavity-nesting bird community at Eglin. Large, mature pine snags were abundant, exceeding other reported densities for southern pine forests. Pine snags were heavily-used, despite the abundance of …
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Woodpecker Nesting Habitat in a Prairie River Woodland
… nested in American elm (Ulmus americana) snag stands with an open canopy and sparse woody understory. Functions involving common clickers or downy woodpeckers were relatively less effective at separating groups because they were more versatile in site selection. Common flickers utilized …
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Bats and trees in a managed forest
… historical roost trees and the probability of a snag roost falling. I found we were more likely to detect larger trees with taller surrounding vegetation and that tree species resistant to decay were more likely to remain standing, providing potentially usable habitat for bats. My results …
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NEST SITE CHARACTERISTICS OF LEWIS’S WOODPECKER (MELANERPES LEWIS) IN RIPARIAN SYSTEMS OF WESTERN MONTANA
… showed that Lewis’s Woodpeckers used larger snags in areas with relatively high percent shrub cover and relatively high snag density per hectare. Snags provide perches to forage from, cavities for nesting, and an open canopy, while the shrub understory supports arthropod prey. From a …
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NEST SITE CHARACTERISTICS OF LEWIS’S WOODPECKER (MELANERPES LEWIS) IN RIPARIAN SYSTEMS OF WESTERN MONTANA
… showed that Lewis’s Woodpeckers used larger snags in areas with relatively high percent shrub cover and relatively high snag density per hectare. Snags provide perches to forage from, cavities for nesting, and an open canopy, while the shrub understory supports arthropod prey. From a …
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Aquatic Macroinvertebrate Production in Predominant Habitats of a Warmwater Stream: The James River, South Dakota
… for macroinvertebrate colonization were sampled: snags (fallen trees and woody debris), rock (areas of stony substrata), and mud (areas lacking instream features with streambeds consisting of fine unconsolidated sediments). Sampling stations were established in areas where instream habitat was …
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Differences in Fish Abundance Among Habitat Types in a Warmwater Stream; The James River, South Dakota
… (areas of gravel or rubble substrate), snags (woody debris), low-head dams and rock-crossings, and tributary confluences. River reaches lacking instream features (i.e. physically simple habitats) served as references. Fish were sampled with double-wing trap nets and beach seines from May …
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Evaluation of kickback energies in abrasive chain saws and cut-off saws: a theoretical and experimental study
… far more dangerous than a tip-engagement or snag type kickback for abrasive saws.
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Chinese Tallow Long-Term Impact on Stand Dynamics in a Bottomland Hardwood Forest Following Vegetation Management
… were observed having sprouts growing out of the snag. There was no correlation between snag diameter at breast height and maximum sprout height (<em>p</em> = 0.172). I found no support for my hypotheses that Chinese tallow and native tree densities responded to herbicide application. Overall …
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PILOT STUDY ON THE PREDICTION OF HEART ROT IN APPARENTLY SOUND WESTERN LARCH
… routinely emphasize decayed trees in their snag retention prescriptions. Where too few trees are present with obvious indicators of decay, apparently sound trees are left to meet retention objectives. These trees may also contain decay, and may offer advantages in longevity and protection …
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PILOT STUDY ON THE PREDICTION OF HEART ROT IN APPARENTLY SOUND WESTERN LARCH
… routinely emphasize decayed trees in their snag retention prescriptions. Where too few trees are present with obvious indicators of decay, apparently sound trees are left to meet retention objectives. These trees may also contain decay, and may offer advantages in longevity and protection …
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An investigation of the stickinness mechanism and the role of nodes in cribellar spider capture thread
… produce fibrils with nodes. Cribellar fibrils snag and hold rough surfaces, but other forces are required to explain their adherence to smooth surfaces. Threads of Hypochilus pococki (Hypochilidae) that are formed of non-noded fibrils hold to a smooth acetate surface with the same force under …
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Habitat use by fishes of the New River, West Virginia
… than densities in middle pool and run habitats. Snag and edge riffie habitats supported the highest densities of fish. Habitat use and activity shifts between daytime and nighttime were found for many species. Fish species and lifestage composition and densities differed among the habitat types, …
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Avian population densities, habitat use, and foraging ecology in thinned and unthinned hardwood forests in Southwestern Virginia
… Densities of shrubs, saplings, trees, and snags, canopy and ground cover, and foliage volume were the structural variables most influenced by thinning. Populations of shrub/understory birds were higher in thinned stands than unthinned stands. Canopy-dwelling species showed variable …
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Submerged wood inhabiting macoinvertebrates of the Elm Fork of the Trinity River, Texas: Assemblage analyses, comparisons to the benthic fauna, and a study of Cyrnellus fraternus (Trichoptera: Polycentropodidae)
… variability of macroinvertebrates inhabiting snags were examined from an 8-km segment of the Elm Fork of the Trinity River. Seventy-seven macroinvertebrate taxa were collected from submerged wood during the study. Assemblages were highly variable spatially and temporally, especially among …
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Life history and secondary production of Cheumatopsyche spp. in a small Appalachian stream with two different land uses on its watershed
… below food-enriched reservoir releases or from snag habitat in southeastern, coastal-plain rivers. Detritus was the greatest component of the diet of Cheumatopsyche at the two sites, but detritus and animal food had similar contribution to production downstream. The adjustment in life history …
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The 2006 Warm Fire: effects on habitat and prey species of the northern goshawk
… Forest habitat metrics such as live tree and snag densities, cone production, canopy and ground cover estimates were collected from 2007-2010 on 60 0.5km transects to compare the effects of high- and low-severity fire and no fire on a suite of 13 important prey species of the goshawk. I …
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Caracterización funcional de Snail2 como represor de cadherina- E y como regulador del proceso de carcinogenésis química
… studies showed that Snail2 required the SNAG (Snail common domain and Gfi-1) and SLUG domains for the recruitment of different co-repressors, such as mSin3A, NCoR and CtBP1, and that these co-repressors functionally interact during transcriptional repression -E-cadherin. We have also …
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Temporal Change in Fish Communities and Modification of the Index of Biotic Integrity for the James River of the Dakotas
… abundance of fish among four major habitats (snag, low head dam. rocky bottom. and simple) following a wet I dry hydrologic cycle. Comparison of species richness data for the entire James River basin in North and South Dakota revealed 41 species being collected during 1975 while 50 species …
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