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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.
11

Structure of downed woody and vegetative debris in old-growth Sequoia sempervirens forests /

Graham, Bradley D. January 1900 (has links)
Thesis (M.S.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 71-82). Also available via Humboldt Digital Scholar.
12

Aquatic-terrestrial linkages in Appalachian streams influence of riparian inputs on stream habitat, brook trout populations, and trophic dynamics /

Sweka, John A. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 198 p. : ill., maps. Vita. Includes abstract. Includes bibliographical references.
13

Spatial organization, position, and source characteristics of large woody debris in natural systems /

Fox, Martin J. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 70-77).
14

An Analysis of the Ecology and Public Perception of Coarse Woody Debris in Virginia

Fuhrman, Nicholas E. 21 July 2004 (has links)
Coarse woody debris (CWD) is an important habitat component for wildlife, fish, and plants and is important in nutrient cycling and soil formation. Knowledge of the volume, distribution, and use of CWD across Virginia would be useful to forest managers modeling nutrient budgets in southeastern forests and is important to wildlife management efforts. Knowledge of the effectiveness of informational brochures and cooperative learning activities/presentations at influencing public perception of CWD is important to program design and evaluation efforts in teaching and extension. The objectives of this study were to quantify the relationship between forest cover type and CWD volume, correlate CWD volume with small mammal and bird activity, distribute information on the advantages and disadvantages of CWD using informational brochures and cooperative learning activities/presentations, and compare the effectiveness of such teaching techniques at influencing public perception of CWD. The volume and wildlife use of CWD was assessed within 12 mature second-growth stands in Virginia. Volume of CWD was measured using fixed-area plots. Use of CWD by small mammals and birds was assessed by noting bodily, foraging, or movement evidence. Pre- and post-survey instruments were used to evaluate how perceptions were altered in first year college students who either reviewed an informational brochure or participated in a cooperative learning activity/presentation. Results suggested that the management of CWD for wildlife was most needed in southeastern Virginia where CWD volumes were lowest and that the value of CWD for wildlife was best conveyed through cooperative learning activities/presentations and may be important to landowner education efforts. Results suggested that management efforts to increase CWD volumes in Virginia should focus on coniferous dominated stands where CWD volumes were lowest. Such a finding, combined with the knowledge that the value of CWD was best conveyed through presentations, suggests that landowners of coniferous woodlots could be effectively educated with presentations. Given that brochures were more effective for females than males, brochures addressing natural resource issues might be the most appropriate, cost effective method of education at events that target female audiences. Knowledge gained from this study that CWD management for wildlife would be most appropriate in western Virginia where CWD was most used by wildlife for travel and that presentations were most effective at reaching suburban participants may be important to outreach program design efforts. Regardless of academic major, presentations were more effective at generating positive attitudes toward CWD. The results of this study suggest that the choice between informational brochures and presentations for influencing public perceptions of CWD will likely be influenced by the demographics of the target audience and the relevance of the topic locally. / Master of Science
15

Coarse Woody Debris and the Carbon Balance of a Moderately Disturbed Forest

Schmid, Amy V 01 January 2015 (has links)
Landscapes are comprised of multiple ecosystems shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence, in contrast to severe disturbances that fell trees, may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (RE). However, woody debris dynamics are rarely examined following moderate disturbances that substantially increase standing dead wood stocks. We used an experimental manipulation of moderate disturbance in an upper Great Lakes forest to: 1) examine decadal changes in CWD stocks through a moderate disturbance; 2) quantify in situ CWD respiration during different stages of decay for downed and standing woody debris and; 3) estimate the annual contribution of CWD respiration to the ecosystem C balance through comparison with RE and net ecosystem production (NEP). We found that the standing dead wood mass of 24.5 Mg C ha-1 was an order of magnitude greater than downed woody debris stocks and a large source of ecosystem C flux six years following disturbance. Instantaneous in situ respiration rates from standing and downed woody debris in the earliest stages of decay were not significantly different from one another. Independently derived estimates of ecosystem CWD respiration of 1.1to 2.1 Mg C ha-1 yr-1 six years following disturbance were comparable in magnitude to NEP and 12.5 % to 23.8 % of RE, representing a substantial increase relative to pre-disturbance levels. Ecosystem respiration and NEP were stable following moderate disturbance even though ecosystem CWD respiration increased substantially, suggesting a reduction in the respiratory C contribution from other sources. We conclude that CWD is an essential component of the ecosystem C balance following a moderate forest disturbance.
16

The imprint of coarse woody debris on soil biological and chemical properties in the western Oregon Cascades

Spears, Julie D. H. 03 April 2002 (has links)
The abundance and spatial heterogeneity of coarse woody debris (CWD) on the forest floor is a prominent feature of Pacific Northwest (PNW) forest ecosystems. The effect of CWD on soil solution chemistry, nutrient cycling and availability, soil physical structure and formation of soil organic matter, however, remains unknown. Therefore, studies on the spatial and temporal imprint of CWD on forest soils are timely and can fill critical gaps in our understanding of the role of CWD in PNW forest ecosystems. I investigated the effect of CWD on soils and soil solution at the H.J. Andrews Experimental Forest in a two-part study. Mineral soils were sampled beneath CWD to a depth of 60 cm. The top 15 cm of soil was also repeatedly sampled for seasonal differences. Control leachate, CWD leachate and soil solution from control soils and from under CWD were collected from the fall of 1999 until the spring of 2001. Results indicated that CWD leachates were much more acidic than water leaching from the forest floor without CWD. Intermediate stages of CWD decomposition had the highest concentrations of hydrophobic compounds and polyphenols of all stages of decay. Correspondingly, surface soils sampled from under well-decayed CWD were more acidic and had more exchangeable acidity and aluminum, and a lower percent base saturation than soils under the forest floor. Nutrient pools were not different under CWD, although nitrogen fluxes were slower under CWD. Although we had hypothesized that the spatial variability of CWD inputs may affect forest soils under CWD, we found that the spatial variability is much more temporal than I had hypothesized and is limited to the top five centimeters of the underlying soil. / Graduation date: 2002
17

Measurement and modeling of the forest carbon resource in the Nothofagus forests of Tierra del Fuego, Chile /

Swanson, Mark Ellyson. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 124-142).
18

Recruitment trends and physical characteristics of course woody debris in Oregon Coast Range streams /

Heiman, David C. January 1988 (has links)
Thesis (M.S.)--Oregon State University, 1989. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
19

Dead wood dynamics and relationships to biophysical factors, forest history, ownership, and management practices in the Coastal Province of Oregon, USA /

Kennedy, Rebecca S. H. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 161-174). Also available on the World Wide Web.
20

Effects of fine woody debris on juvenile brown trout (Salmo trutta) and drifting invertebrates

Enefalk, Åsa January 2014 (has links)
In boreal forest streams, woody debris is an important habitat component. Stream invertebrates and salmonids such as brown trout benefit from in-stream wood. The studies presented in this thesis explore how drifting stream invertebrates respond to addition of fine woody debris, and how young-of-the-year (0+) brown trout behave in habitats with and without fine woody debris. The first paper reports results from a field experiment where fine woody debris was added to streams, and invertebrate drift was measured in order to detect impacts of the fine woody debris on drift density, biomass and taxon diversity. In the end of the season, the fine woody debris-affected drift samples showed higher density, biomass and taxon diversity than the control samples. In the second paper, I describe effects of fine woody debris on 0+ brown trout, studied in laboratory stream channels. Trout were tested in habitats without fine woody debris, with an intermediate fine woody debris density, and with a high fine woody debris density. Swimming activity and foraging time were significantly lower when fine woody debris was present than when it was absent. More time was spent sheltering at the high fine woody debris density than at the intermediate one. The increasing exploitation of fine woody debris for biofuel purposes should be considered in relation to the effects on brown trout and stream invertebrate habitat. / <p>Artikel 1 ingick i avhandlingen som manuskript med titeln "Effects of fine wood addition on invertebrate drift in boreal forest streams". Nu publicerad.</p>

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