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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.
21

An assessment of the representation of fire severity and coarse woody debris dynamics in an ecosystem management model

Boldor, Irina Angelica 05 1900 (has links)
Fire is the most significant natural disturbance agent in the MSdm biogeoclimatic subzone and has a determinant role in the dynamics of lodgepole pine (Pinus contorta ssp. latifolia Engelm.ex S.Wats.) dominated forests. Fire severity is a controversial term that usually refers to a qualitative measure of the fire effects on soil and vegetation and ultimately on ecosystem sustainability. The main objective of the thesis was to evaluate methods for quantifying and modelling the effects of fire severity on live biomass and dead organic matter and post-fire coarse woody debris (CWD) dynamics. A review of the representation of fire in models was conducted and several of the most commonly used fire models in North America have been described in terms of fire severity representation. The potential for developing the fire severity concept as a fire effects descriptor in an ecosystem management model were assessed. Severity matrices summarizing the probabilities of occurrence for fires of varying severity were constructed for two sites in the MSdm biogeoclimatic subzone of British Columbia, using weather data and past fire records. These matrices provide information to improve fire representation in the ecosystem based model FORECAST by quantifying the effects of fire severity on dead and live biomass components. Although this represents only a preliminary step, the severity matrix approach appears toprovide a viable methodology for improving the representation of fire effects in FORECAST. Patterns of post-fire coarse woody debris (CWD) accumulation were also assessed in the context of model development. Data were collected from a chronosequence of fire affected sites in the MSdm subzone of the TFL 49 Kelowna. The ability of the FORECAST model to simulate accumulation patterns in CWD and soil organic matter and nitrogen following fire was tested by comparing model outputs with field data. The evaluation of the model against chronosequence-derived data highlighted the fact that caution needs to be taken when using such data for model testing. The very slow recruitment pattern for new CWD illustrates the need to retain sources of CWD recruitment following fire by not salvage logging all killed trees and/or surviving live trees.
22

An assessment of the representation of fire severity and coarse woody debris dynamics in an ecosystem management model

Boldor, Irina Angelica 05 1900 (has links)
Fire is the most significant natural disturbance agent in the MSdm biogeoclimatic subzone and has a determinant role in the dynamics of lodgepole pine (Pinus contorta ssp. latifolia Engelm.ex S.Wats.) dominated forests. Fire severity is a controversial term that usually refers to a qualitative measure of the fire effects on soil and vegetation and ultimately on ecosystem sustainability. The main objective of the thesis was to evaluate methods for quantifying and modelling the effects of fire severity on live biomass and dead organic matter and post-fire coarse woody debris (CWD) dynamics. A review of the representation of fire in models was conducted and several of the most commonly used fire models in North America have been described in terms of fire severity representation. The potential for developing the fire severity concept as a fire effects descriptor in an ecosystem management model were assessed. Severity matrices summarizing the probabilities of occurrence for fires of varying severity were constructed for two sites in the MSdm biogeoclimatic subzone of British Columbia, using weather data and past fire records. These matrices provide information to improve fire representation in the ecosystem based model FORECAST by quantifying the effects of fire severity on dead and live biomass components. Although this represents only a preliminary step, the severity matrix approach appears toprovide a viable methodology for improving the representation of fire effects in FORECAST. Patterns of post-fire coarse woody debris (CWD) accumulation were also assessed in the context of model development. Data were collected from a chronosequence of fire affected sites in the MSdm subzone of the TFL 49 Kelowna. The ability of the FORECAST model to simulate accumulation patterns in CWD and soil organic matter and nitrogen following fire was tested by comparing model outputs with field data. The evaluation of the model against chronosequence-derived data highlighted the fact that caution needs to be taken when using such data for model testing. The very slow recruitment pattern for new CWD illustrates the need to retain sources of CWD recruitment following fire by not salvage logging all killed trees and/or surviving live trees.
23

Woody plant adaptations to water stress in arid shrub communities

Jacobsen, Anna Linden. January 2008 (has links)
Thesis (Ph.D.)--Michigan State University. Plant Biology, 2008. / Title from PDF t.p. (viewed on Mar. 30, 2009) Includes bibliographical references (p.197-216). Also issued in print.
24

Woody species and forest structure in northern Missouri riparian forests with different ages and watershed sites

Faust, Thomas McCullough. January 2006 (has links)
Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 1, 2009) Vita. Includes bibliographical references.
25

Studies of water transport and water deficits in woody plants

Chaney, William R. January 1969 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
26

Direct seeding of native species for reforestation on degraded hillsides in Hong Kong

Chick, Hiu-lai. January 2004 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2004. / Title from PDF t.p. (viewed on Dec. 19, 2005). Includes bibliographical references (leaves 144-163). Also issued in print manuscript.
27

Brook trout response to canopy and large woody debris manipulations in Appalachian streams

Niles, Jonathan M. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vi, 200 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references.
28

The natural history and dynamics of large wood in the Queets River, Washington /

Latterell, Joshua J. January 2005 (has links)
Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 154-167).
29

Recruitment and abundance of large woody debris in an Oregon coastal stream system /

Long, Barry A. January 1987 (has links)
Thesis (M.S.)--Oregon State University, 1987. / Typescript (photocopy). Includes bibliographical references (leaves 60-65). Also available on the World Wide Web.
30

An assessment of the representation of fire severity and coarse woody debris dynamics in an ecosystem management model

Boldor, Irina Angelica 05 1900 (has links)
Fire is the most significant natural disturbance agent in the MSdm biogeoclimatic subzone and has a determinant role in the dynamics of lodgepole pine (Pinus contorta ssp. latifolia Engelm.ex S.Wats.) dominated forests. Fire severity is a controversial term that usually refers to a qualitative measure of the fire effects on soil and vegetation and ultimately on ecosystem sustainability. The main objective of the thesis was to evaluate methods for quantifying and modelling the effects of fire severity on live biomass and dead organic matter and post-fire coarse woody debris (CWD) dynamics. A review of the representation of fire in models was conducted and several of the most commonly used fire models in North America have been described in terms of fire severity representation. The potential for developing the fire severity concept as a fire effects descriptor in an ecosystem management model were assessed. Severity matrices summarizing the probabilities of occurrence for fires of varying severity were constructed for two sites in the MSdm biogeoclimatic subzone of British Columbia, using weather data and past fire records. These matrices provide information to improve fire representation in the ecosystem based model FORECAST by quantifying the effects of fire severity on dead and live biomass components. Although this represents only a preliminary step, the severity matrix approach appears toprovide a viable methodology for improving the representation of fire effects in FORECAST. Patterns of post-fire coarse woody debris (CWD) accumulation were also assessed in the context of model development. Data were collected from a chronosequence of fire affected sites in the MSdm subzone of the TFL 49 Kelowna. The ability of the FORECAST model to simulate accumulation patterns in CWD and soil organic matter and nitrogen following fire was tested by comparing model outputs with field data. The evaluation of the model against chronosequence-derived data highlighted the fact that caution needs to be taken when using such data for model testing. The very slow recruitment pattern for new CWD illustrates the need to retain sources of CWD recruitment following fire by not salvage logging all killed trees and/or surviving live trees. / Forestry, Faculty of / Graduate

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