Forest Sciences Commons^™

Implementing Complex Partial Harvests In Central Maine: Is Tree Marking Necessary?, Sam Grimm

Electronic Theses and Dissertations

Recent trends in forest management regimes seek to strike a balance between a multitude of ecologic and economic values at multiple scales. Whether the objectives are traditional (timber production), or contemporary (ecological sustainability), the fundamental, practical question of “how” the forester implements a silvicultural prescription remains relatively unaddressed by research. Forest managers must consider: what good are carefully designed landscape plans and stand-level prescriptions if the treatments are not executed accurately? In northeastern North America, tree marking -- the simple designation of cut or leave trees to implement a given silvicultural prescription -- has declined, in favor of reliance on …

Forest Harvesting Productivity And Cost In Maine: New Tools And Processes, Patrick Hiesl

Electronic Theses and Dissertations

Computer simulations have been used in forestry and forest operations since around 1960. In many cases such simulations can be used to answer questions that would be time consuming and expensive to investigate in a real-life environment. This dissertation focuses on the use of computer simulation in forest operations to answer questions regarding the profitability of technological advancements, investments in precommercial thinning (PCT), and the use of different harvesting systems. To explore the benefits of decoupling a harvesting system, a new simulation method, called agent based modeling was used. Agent based modeling is primarily used in social sciences but now …

Survival And Growth Of Reserve Trees In An Expanding-Gap Silvicultural System 20 Years After Establishment, David R. Carter

Electronic Theses and Dissertations

Land managers today are increasingly called upon to retain and restore late-successional features on harvested landscapes in order to reverse the current global decline of large, old trees and their associated elevated levels of biodiversity and ecosystem function. Such retention practices are commonly thought to result in increased rates of mortality as a result of exposure to wind, thus compromising management objectives. This study investigated the survival and growth dynamics of the reserve trees retained in harvested gaps (n=787) established 20 years prior in the Acadian Forest Ecosystem Research Project (AFERP) in east-central Maine.

A high (relative to similar treatments …

Individual Tree Measurements From Three-Dimensional Point Clouds, Elias Ayrey

Electronic Theses and Dissertations

This study develops and tests novel methodologies for measuring the attributes of individual trees from three-dimensional point clouds generated from an aerial platform. Recently, advancements in technology have allowed for the acquisition of very high resolution three-dimensional point clouds that can be used to map the forest in a virtual environment. These point clouds can be interpreted to produce valuable forest attributes across entire landscapes with minimal field labor, which can then aid forest managers in their planning and decision making.

Biometrics derived from point clouds are often generated on a plot level, with estimates spanning many meters (rather than …

Seasonal Influences On Habitat Use By Snowshoe Hares: Implications For Canada Lynx In Northern Maine, Sheryn J. Olson

Electronic Theses and Dissertations

Snowshoe hares (Lepus americanus) respond to seasonal changes in vegetation in the northern and western portions of their range. During winter, hares use dense conifer stands that may provide thermal and predatory refugia, then during summer move to areas with more herbaceous food and cover. These movements influence hare demographics, with greater survival rates corresponding to seasonal use of dense, primarily coniferous stands. Different harvesting practices in commercial forests produce vegetative communities that may support differing hare densities among forest stand- types between seasons, but seasonal use of habitat had not been documented in northern Maine on a large spatial …