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Full-Text Articles in Forest Sciences

Leaf Area, Stemwood Volume Growth, And Stand Structure In A Mixed-Species, Multi-Aged Northern Conifer Forest, Laura Kenefic Dec 2000

Leaf Area, Stemwood Volume Growth, And Stand Structure In A Mixed-Species, Multi-Aged Northern Conifer Forest, Laura Kenefic

Electronic Theses and Dissertations

Tree- and stand-level leaf area (LA) - stemwood volume growth relationships were explored in mixed-species, multi-aged northern conifer stands dominated by Tsuga canadensis (L.) Carr. (eastern hemlock), Abies balsameu (L.) Mill. (balsam fir), and Piceu rubens Sarg. (red spruce). A T. cunudensis LA model was developed to supplement published equations for A. bulsumeu and P. rubens. Sapwood area was an effective T. cunudensis LA surrogate, though nonsapwood-based models using stem cross-sectional area and modified live crown ratio produced results comparable to sapwood-based models. Equations for predicting tree-level stemwood volume increment (AVINC) were derived, and implied growth efficiencies (GE) were …


Factors Influencing Net Primary Production In Red Spruce, Michael Day Dec 2000

Factors Influencing Net Primary Production In Red Spruce, Michael Day

Electronic Theses and Dissertations

Management of forest resources, even when practiced at the scale of ecosystems, is implicitly based on managing photosynthetic acquisition of carbon by trees. This thesis examines several aspects of carbon balance at the scale of individual trees, using red spruce (Picea rubens Sarg.) as a model species. Age-related declines in net primary productivity have been described for many species, including red spruce. A potential explanation is that ontogenetic changes in meristems lead to lower photosynthetic rates, which was confirmed here for red spruce. A grafting study used scions from juvenile, 6Oy, and 120~ trees to demonstrate that age-related morphological …


Creating Virtual Wood Particulate Composites, Huaijun Wang Dec 2000

Creating Virtual Wood Particulate Composites, Huaijun Wang

Electronic Theses and Dissertations

Wood particulate composites are inhomogeneous, short fiber materials. The behavior of such materials depends on the properties of the constituent elements (wood particles, fibers, and adhesives) and the manner in which they are organized (the microstructure). Research on the microstructure of these composites has been carried out for several decades. However, due to the complexity of the engineered structures, most existing works are either over-simplified or lacking in general representations. While experimental approaches to improve material performance are necessary, this thesis presents another approach for better depictions of such complex systems. In this research project, digital surrogates of the composite …


Does Elevated Nitrogen And Sulfur Deposition Lead To Net Base Cation Losses In Northern New England Forest Soils?, Ivan J. Fernandez, Stephen A. Norton, Jeffrey Kahl, Lindsey E. Rustad Aug 2000

Does Elevated Nitrogen And Sulfur Deposition Lead To Net Base Cation Losses In Northern New England Forest Soils?, Ivan J. Fernandez, Stephen A. Norton, Jeffrey Kahl, Lindsey E. Rustad

University of Maine Office of Research Administration: Grant Reports

The aims of this research are to continue treatment and monitoring of a paired watershed experiment at Bear Brook in northern Maine, with an emphasis on changes in soil base cations, particularly calcium. Base cation depletion is well-recognised as a potential problem in soils that have been subjected to acidic N deposition but few data exist from well-controlled, long-term experiments. The Bear Brook watershed has been periodically treated with ammonium sulfate since the fall of 1989 and is believed to be approaching N saturation. Since 1993 the relationship between base cations and strong acid anions has changed, such that labile …


Mp742: 4th Annual Munsungan Conference Proceedings: Forest Health, William D. Ostrofsky, T. J. Dragon Mar 2000

Mp742: 4th Annual Munsungan Conference Proceedings: Forest Health, William D. Ostrofsky, T. J. Dragon

Miscellaneous Publications

These conference proceedings provide viewpoints on a variety of important and defining aspects of forest health. Forest managers, landowners, and scientists have long appreciated the direct effects that insects, diseases and damaging weather can have on forests. Over the past fifty years the Maine landscape has been affected by numerous outbreaks of defoliators such as the gypsy moth and the spruce budworm, by white pine blister rust and beech bark disease, and most recently by severe ice storm damage, along with countless other pests and catastrophic storms. During the past several years, the public also has become increasingly aware of …


Maine Forests: A Century Of Change, 1900-2000…And Elements Of Policy Change For A New Century, Lloyd Irland Jan 2000

Maine Forests: A Century Of Change, 1900-2000…And Elements Of Policy Change For A New Century, Lloyd Irland

Maine Policy Review

At the close of the 19th century, the state’s forest area was at an all time low; land ownership was changing rapidly with the emergence of new paper companies; a growing number of wildlife species were threatened; and widespread unease over the future of Maine’s forests was evident. Today a similar unease is evident. Many believe the state’s spruce-fir forest is being overcut; land ownership is changing rapidly; fear exists that the sustainability of Maine’s forests; and wildlife populations have been severely compromised. Given the similarity in circumstance, one might ask whether there has been any change over the past …


Evaluating The Durability Of Wood/Frp Bonds Through Chemical Kinetics Using A Range Of Mechanical Test Methods, Jonathan Philip Alexander Jan 2000

Evaluating The Durability Of Wood/Frp Bonds Through Chemical Kinetics Using A Range Of Mechanical Test Methods, Jonathan Philip Alexander

Electronic Theses and Dissertations

Hybrid composites of wood and fiber reinforced polymers (FRP) exhibit a flexibility of design properties through choices in fiber type, amount, orientation and resin type. With this flexibility comes the need to measure the durability of the composite material system, especially the bond between these two materials due to their markedly different responses to moisture. This study is two-fold; the first section examines methods for the mechanical testing and durability of wood/FRP laminations. Six mechanical tests were evaluated and a modified block shear method was identified as the most suitable due to its ability to provide representative results independent of …