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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effects of thinning intensity on snag and cavity tree abundance in an Appalachian hardwood stand

Graves, Aaron T. January 1999 (has links)
Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains viii, 75 p. : ill., map. Includes abstract. Includes bibliographical references (p. 33-41).
2

Conifer regeneration, understory vegetation and artificially topped conifer responses to alternative silvicultural treatments /

Huff, Tristan. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 73-77). Also available on the World Wide Web.
3

Snag longevity, bird use of cavities, and conifer response across three silvicultural treatments in the Oregon Coast Range /

Walter, Scott T. January 2003 (has links)
Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
4

Lavar på död ved : En jämförelse mellan död ved där det brunnit respektive inte brunnit i Tyresta nationalpark och naturreservat / Lichens on dead wood : A comparison between dead wood in burnt and unburnt areas of Tyresta National Park and nature reserve

Fältström, Leonora January 2019 (has links)
Burned forests provide plenty of dead wood that can host rare and threatened species, especially fire dependent species that need charred wood to survive. Few studies have investigated the difference in lichen assemblages on dead wood in forests that have burned with those that have not. In this study lichens on snags of Pinus sylvestris in burnt and unburnt areas of Tyresta national park and nature reserve were investigated, with the aim to assess differences in lichen diversity and richness. In total 42 trees were analysed, and 25 species were identified. No threatened or rare species were found in the burnt area, possibly as none of the snags were charred. There was no significant difference in diversity or richness between burnt and unburnt areas. However, lichens were generally more abundant in the burnt area where the light levels also were higher, especially on the northern sides of the snags. Only macrolichen species were significantly more abundant in the burnt area. The species composition in the areas differed slightly with a majority of microlichen species in the unburnt area while the burnt area had equally many macro- and microlichen species. However, several species of microlichen were missing in the burnt area. Together with previous studies this could indicate that microhabitats forming post-fire are favourable for some lichen but not for others. Further studies are needed to confirm which species are favoured by burning to optimize the restoration and managing of burned forests as well as the conservation of threatened species.
5

The relationships between snags and cavity-nesting birds in a gypsy moth impacted forest

Showalter, Christopher Ryan. January 2000 (has links)
Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains vii, 59 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references (p. 23-28).
6

Deadwood Dynamics: A Case Study at Prince William Forest Park, Virginia

Maslyukova, Daria Yurevna 25 April 2024 (has links)
Deadwood, characterized as both downed woody material (DWM) and standing and dead stems, i.e., snags, is a significant component of terrestrial forest ecosystems. Deadwood amount and structure may influence potential wildfire hazard by altering combustible DWM mass and creating fuel structures that increase fire intensity and spread. Deadwood is also critical to carbon storage and nutrient cycling and may vary based upon the size classes of individual deadwood pieces. Lastly, deadwood structural variability has been found to positively affect species richness in bees, salamanders, birds, and small mammals, such as shrews and woodland mice. However, in the Mid-Atlantic Piedmont, there are no accessible tools to rapidly estimate deadwood of long unmanaged second growth forests to help inform future management decisions. Management agencies within this region, such as the National Park Service, may benefit from a greater understanding of the potential factors that influence deadwood accumulation, retention, and decomposition. Therefore, a project was funded by the National Park Service to investigate deadwood dynamics at Prince William Forest Park (PRWI). From May to August 2023, a deadwood inventory was conducted using planar intercepts nested within fixed radius plots along the gradient of forest cover types, aspect, elevation, and soil orders found within PRWI. Forest cover type was significant in the generalized linear model for percent dead basal area, total DWM, fine woody material, litter, and duff mass. The Virginia pine (Pinus virginiana) forest cover type had the highest percent dead basal area and total DWM mass per hectare. Elevation, aspect, and soil order were not significantly related to percent dead basal area, total DWM, 1,000 hr, fine woody material, litter, and duff mass. Data from this study may serve as a baseline for similar second growth forests of the mid-Atlantic Piedmont. / Master of Science / Visitors to Prince William Forest Park (PRWI) in eastern Virginia have voiced concern about forest health within PRWI. The perception of a high number of standing and dead stems, or snags, and a high number of decaying logs, branches, and twigs on the ground has been a focal point for visitors. Some perceive the dead material on the ground as a potential source of fuel for wildfires. Others perceive the potential hazard to humans along trails and vistas if snags were to fall. However, snags and downed woody material, known as deadwood, are critical components of forests because they store carbon and nutrients long-term and may provide habitat and resources for many wildlife species. Many other heavily used recreation locations in the eastern US face similar deadwood and forest health challenges. To respond to this, we assessed deadwood in PRWI to determine how it may be distributed differently across the variety of landscape features that are present within the park. We found the amount of total downed and dead material on the forest floor increased as the percentage of trees that were standing and dead increased. The amount of dead material on the ground was greatest for the Virginia pine (Pinus virginiana) forest community type, whereby PRWI's stands have reached their life expectancy. Prince William Forest Park's managers and those elsewhere at similar locations throughout the eastern US may benefit from this information as they seek to evaluate the status of their resources, manage those resources, and provide thoughtful messaging to the public regarding the significance and maintenance of deadwood as an ecosystem resource.
7

Hur påverkar naturvårdsåtgärder mängden av vedlevande insekter : Manuellt dödade träd vs självdöda / How conservation measures affect the standing crop of wood-living insects : Manually killed trees vs. snags

Persson, Andreas January 2012 (has links)
Today’s forest managers implement a large number of methods to increase the amount of dead wood in Swedish forests. They use everything from high cutting of trees to girdling trees and burning forests. However, implementation of these measures without proper knowledge of their consequences is a common problem. This study has been performed to increase knowledge about two of these measures, girdling and high cutting, and how these actions affect the number of wood-living insects living on dead trees. A total of 72 trees were randomly selected in four different locations in the municipality of Säffle. The trees, which were birch and alder, were all dead or dying and selected by three criteria, snags (as the reference tree type), girdling and high cut. A total of 15 trees of each type and measure were chosen. The trees which were either ring debarked or high cut were compared with snags to see if there were any differences in the number of wood-living insects. The collections of insects were made with so-called appropriate window traps. The traps were tied to the trees and left out for one week before emptying. The traps 2 were deployed on two separate occasions during June and July 2011. A total of 876 beetle individuals were captured during the study, including 13 longhorn beetles. There was a significantly smaller amount of families in high cut birch compared to the birch snags for the first period, but none for the second period. There were also a significantly smaller amount of families in the girdled birch than in the snags for the second period. There were no differences between the different types of dead trees when comparing insect species. There were no significant differences between the girdled alder and the alder snags, which indicate that girdling does not have a strong effect, although catches were greater for the girdled alder. High cut alder does not exist and therefore only girdled alder could be compared with the alder snags and no differences in insect catches were found. There were differences in sizes of the trees, with birch snags being larger than high cut and girdled birch and alder snags being smaller than debarked alder. There was also a significant difference in degradation rate of birch, with natural birch snags being less decayed than the high cut and girdled birch. There was no difference in the degree of decay for alder. 69 % of the trapped longhorn beetles were found in birch, 31 % on the alder, but this difference was not significant. The conclusion of the study was that high cutting birch leads to a smaller number of tree-living insects than found on natural snags and that the same applies to girdling. Alder requires further study.
8

Birds and small mammals, intensively established pine plantations, and landscape metrics of the Coastal Plain

Hanberry, Brice Bond 15 December 2007 (has links)
I evaluated effects of 5 treatments for pine plantation establishment on breeding and wintering birds and small mammals during years one through 5 post-treatment in the Lower Coastal Plain of Mississippi. I modeled relationships between 8 vegetation variables and avian abundance to identify influential habitat components in pine plantations. At the landscape scale, I compared avian abundance of regionally important species with land class variables in the Coastal Plain of Georgia. In pine plantations, species richness, total abundance, and 2 conservation bird metrics generally decreased with increasing intensity of stand establishment. Thus, this study suggests that increasing standmestablishment intensity can reduce avian habitat quality in Coastal Plain pine plantations. Presence of residual trees retained after timber harvest was the most influential variable related to avian abundance, and tree retention may reduce the negative impacts of intensive stand establishment on avian communities. There were minimal treatment effects on common small mammals of young pine plantations. For the Coastal Plain landscape, a mixture ofn area and edge variables were influential in avian models for 10 species, although area or edge each were important for 2 species. Hardwood forests were important vegetation types for all but one modeled species. Assessment of habitat conditions that affect avifauna and small mammals on managed timber production lands can assist natural resource managers with integration of timber production and conservation of biological diversity.
9

Naturhänsyn vid föryngringsavverkningar : En jämförelse mellan certifierade och o-certifierade hyggen / Nature conservation in regeneration fellings : A comparison between certified and non-certified forest clearings

Rylander, Anna January 2015 (has links)
A growing number of Swedish forest owners are choosing to certify their forestry. However, there appears to be a lack of field surveys which describe differences between certified and non-certified forests concerning the degree of completed environmental considerations. In order to know to what extent certified forests contribute towards improved environmental consideration, we need studies on how large the difference is in relation to non-certified forests. Differences between certified and non-certified forest clearings were quantified through an inventory of the number of retention trees, dead trees and snags. The result showed that the retained number of the investigated parameters varied greatly between individual clearings, regardless of certification status. However, the results suggested that the certified clearings had an average higher incidence ofthe investigated parameters. In comparison to statistics of southern Sweden's average, the results also suggested that the certified clearings (from the county “Blekinge”) most of the time had a higher incidence of the investigated parameters, while the non-certified clearings most of the time had a lower incidence of the investigated parameters. The environmental considerations on neither the certified nor the non-certified clearings were found to be near the highest amount that could be required by the Swedish forestry act. This observation is interesting, especially since the certified clearings would be expected to maintain a consistently high level in relation to the law requirement.
10

Presence, relative abundance, and resource selection of bats in managed forest landscapes in western Oregon /

Arnett, Edward B. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

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