Forest Sciences Commons^™

Towards Greater Accuracy In Individual-Tree Mortality Regression, Clara Antón Fernández

Dissertations, Master's Theses and Master's Reports - Open

Background mortality is an essential component of any forest growth and yield model. Forecasts of mortality contribute largely to the variability and accuracy of model predictions at the tree, stand and forest level. In the present study, I implement and evaluate state-of-the-art techniques to increase the accuracy of individual tree mortality models, similar to those used in many of the current variants of the Forest Vegetation Simulator, using data from North Idaho and Montana. The first technique addresses methods to correct for bias induced by measurement error typically present in competition variables. The second implements survival regression and evaluates its …

Risk Assessment For Invasive Exotic Plants Using Multi-Criteria Risk Models, Lindsey Marie Shartell

Dissertations, Master's Theses and Master's Reports - Open

Invasive exotic plants have altered natural ecosystems across much of North America. In the Midwest, the presence of invasive plants is increasing rapidly, causing changes in ecosystem patterns and processes. Early detection has become a key component in invasive plant management and in the detection of ecosystem change. Risk assessment through predictive modeling has been a useful resource for monitoring and assisting with treatment decisions for invasive plants.

Predictive models were developed to assist with early detection of ten target invasive plants in the Great Lakes Network of the National Park Service and for garlic mustard throughout the Upper Peninsula …

System For And Method Of Performing Evaluation Techniques On A Log Or Round Timber, Xiping Wang, Robert J. Ross, James A. Mattson, John Erickson, John W. Forsman, Earl A. Geske, Michael A. Wehr

Michigan Tech Patents

A system for and method of evaluating a log. The system includes an analysis module having at least one input terminal connectable to the at least one input device. The at least one input terminal is operable to receive at least one signal representing at least one measured property of the log and at least one determined parameter of the log determined in response to an energy being applied to the log. The analysis module further includes a processor coupled to the at least one input terminal. The processor determines a predictive modulus of elasticity (MOE) of the log based …

Ecological Studies Of Wolves On Isle Royale, 2004-2005, Rolf O. Peterson, John A. Vucetich

Ecological Studies of Wolves on Isle Royale

Annual Report 2004-2005

Vegetation And Hydrologic Influences On Carbon And Nitrogen In Subsurface Water Of A Forested Riparian Wetland, Emily B. W. Calhoon

Dissertations, Master's Theses and Master's Reports - Open

Vegetation communities affect carbon and nitrogen dynamics in the subsurface water of mineral wetlands through the quality of their litter, their uptake of nutrients, root exudation and their effects on redox potential. However, vegetation influence on subsurface nutrient dynamics is often overshadowed by the influences of hydrology, soils and geology on nutrient dynamics. The effects of vegetation communities on carbon and nitrogen dynamics are important to consider when managing land that may change vegetation type or quantity so that wetland ecosystem functions can be retained. This study was established to determine the magnitude of the influences and interaction of vegetation …

Effectiveness Of A Nondestructive Evaluation Technique For Assessing Standing Timber Quality, Crystal L. Pilon

Dissertations, Master's Theses and Master's Reports - Open

The research presented in this thesis was conducted to further the development of the stress wave method of nondestructively assessing the quality of wood in standing trees. The specific objective of this research was to examine, in the field, use of two stress wave nondestructive assessment techniques.

The first technique examined utilizes a laboratory-built measurement system consisting of commercially available accelerometers and a digital storage oscilloscope. The second technique uses a commercially available tool that incorporates several technologies to determine speed of stress wave propagation in standing trees.

Field measurements using both techniques were conducted on sixty red pine trees …

Riparian Buffer Zones Of The Ybytyruzu Mountain Range, Paraguay, Wendy A. Owens

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.

Genetic Diversity Of Annona Cherimola Mill In South Central Bolivia, Kristina J. Owens

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.

Photodegradation And Photostabilization Of Weathered Wood Flour Filled Polyethylene Composites, Nicole M. Stark

Dissertations, Master's Theses and Master's Reports - Open

Wood plastic composites (WPCs) have gained popularity as building materials because of their usefulness in replacing solid wood in a variety of applications. These composites are promoted as being low-maintenance, high-durability products. However, it has been shown that WPCs exposed to weathering may experience a color change and/or loss in mechanical properties. An important requirement for building materials used in outdoor applications is the retention of their aesthetic qualities and mechanical properties during service life. Therefore, it is critical to understand the photodegradation mechanisms of WPCs exposed to UV radiation and to develop approaches to stabilize these composites (both unstabilized …