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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

Modelling Jack Pine (Pinus banksiana Lamb) and Black Spruce [Picea mariana (Mill.) BSP] growth and yield in Manitoba

XU, WENLI 19 September 2012 (has links)
This study develops forestry growth and yield models for two economically important tree species in Manitoba, black spruce [Picea mariana (Mill.) BSP] and jack pine [Pinus banksiana Lamb]. The growth and yield models developed include regression-based individual tree height growth and site index, tree diameter (basal area) growth, tree bole taper, and individual tree mortality models. These regression-based models were developed empirically, using stem analysis, growth and mortality data from 80 permanent sample plots located within the commercially important boreal forests of Manitoba. Model development involved the exploration, comparison and testing of numerous potential regression models and predictor variables. Statistical issues commonly encountered in forest growth and yield modeling, particularly data autocorrelation and variable multicollinearity, were addressed using nonlinear least squares (NLS), generalized nonlinear least squares (GNLS), and nonlinear mixed-effects model regression (NLMM) approaches. Height growth and site index of black spruce and jack pine was modelled using a three-parameter generalized logistic function. NLMM regression was used since the data were spatially autocorrelated. The inclusion of prior measures from individual trees produced more accurate predictions. In the tree diameter (basal area) growth models, tree size variables were significant predictors for black spruce and managed jack pine stands. Site index (a measure of site productivity) was positively correlated, and basal area of trees larger than the target tree (a relative measure of competition) negatively correlated, with diameter increment. Thiessen polygon area, a spatial measure of competition, was a significant predictor for natural jack pine and upland black spruce stands. Tree bole taper was modeled by NLMM approach using a five-parameter equation based on dimensional analysis, with breast height diameter, total height and relative height as predictor variables. The inclusion of a single prior measure from each tree improved model prediction. Black spruce and jack pine mortality was modeled using logistic regression. The black spruce models predicted high survivorship for larger, fast-growing trees in less crowded stands. In the jack pine model, highest survivorship was predicted for larger, less locally crowded trees.
12

Modelling Jack Pine (Pinus banksiana Lamb) and Black Spruce [Picea mariana (Mill.) BSP] growth and yield in Manitoba

XU, WENLI 19 September 2012 (has links)
This study develops forestry growth and yield models for two economically important tree species in Manitoba, black spruce [Picea mariana (Mill.) BSP] and jack pine [Pinus banksiana Lamb]. The growth and yield models developed include regression-based individual tree height growth and site index, tree diameter (basal area) growth, tree bole taper, and individual tree mortality models. These regression-based models were developed empirically, using stem analysis, growth and mortality data from 80 permanent sample plots located within the commercially important boreal forests of Manitoba. Model development involved the exploration, comparison and testing of numerous potential regression models and predictor variables. Statistical issues commonly encountered in forest growth and yield modeling, particularly data autocorrelation and variable multicollinearity, were addressed using nonlinear least squares (NLS), generalized nonlinear least squares (GNLS), and nonlinear mixed-effects model regression (NLMM) approaches. Height growth and site index of black spruce and jack pine was modelled using a three-parameter generalized logistic function. NLMM regression was used since the data were spatially autocorrelated. The inclusion of prior measures from individual trees produced more accurate predictions. In the tree diameter (basal area) growth models, tree size variables were significant predictors for black spruce and managed jack pine stands. Site index (a measure of site productivity) was positively correlated, and basal area of trees larger than the target tree (a relative measure of competition) negatively correlated, with diameter increment. Thiessen polygon area, a spatial measure of competition, was a significant predictor for natural jack pine and upland black spruce stands. Tree bole taper was modeled by NLMM approach using a five-parameter equation based on dimensional analysis, with breast height diameter, total height and relative height as predictor variables. The inclusion of a single prior measure from each tree improved model prediction. Black spruce and jack pine mortality was modeled using logistic regression. The black spruce models predicted high survivorship for larger, fast-growing trees in less crowded stands. In the jack pine model, highest survivorship was predicted for larger, less locally crowded trees.
13

Infection of jack pine in Wisconsin by Cronartium quercuum and Peridermium harknessii

McGrath, William Thomas, January 1967 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
14

Studies relating to the chemical control of Hylobius radicis BUCH. in young jack pine plantations in northern Wisconsin

Pickens, Lawrence G. January 1966 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
15

Preliminary investigation of the influence of photoperiod and temperature on the development of multivoltine populations of Neodiprion rugifrons Middleton

King, Lonn Louis, January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 43-44.
16

Jack Pine Signalling and Responses to Herbivory

Lazebnik, Jenny Unknown Date
No description available.
17

Induced monoterpene responses in jack pine: defence against jack pine budworm and a fungal associate of the mountain pine beetle

Colgan, Lindsay Jessica Unknown Date
No description available.
18

Induced monoterpene responses in jack pine: defence against jack pine budworm and a fungal associate of the mountain pine beetle

Colgan, Lindsay Jessica 11 1900 (has links)
My thesis research investigated monoterpene responses in jack pine (Pinus banksiana Lamb.) to different agents to better understand how these responses may influence the spread of the mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) in the boreal forest. The results support that monoterpenes are inducible responses in jack pine. In the first study, methyl jasmonate application elicited the greatest response in juvenile and mature trees suggesting that jasmonic acid plays a role in jack pine defence responses. In the cross-induction study, I found evidence of an increase in resistance to Grosmannia clavigera with prior jack pine budworm defoliation (Choristoneura pinus pinus Freeman; JPBW). In contrast, needle monoterpenes greatly increased after G. clavigera inoculation and continued to increase during JPBW defoliation; however, JPBW increased its feeding rate to compensate for a change in host quality. Overall, monoterpene induction in jack pine depended on the agent(s) involved and their order. The systemic responses that were observed may have implications for MPB spread in the boreal forest. / Forest Biology and Managment
19

Factors governing the strength development of kraft pulps

Baker, Raymond E. (Raymond Emerson) 01 January 1940 (has links)
No description available.
20

Interactions Between Host Trees, Bacteria, and Fungi: Impacts on Mountain Pine Beetle (Dendroctonus ponderosae) Reproduction

Therrien, Janet FCA Unknown Date
No description available.

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