With recent advances in artificial intelligence, new methods are being developed that provide faster, and more consistent predictions for data in complex environments. In the field of landscape assessment, where an array of physical variables effect environmental perception, natural resource managers need tools to assist them in isolating the significant predictors critical for the protection and management of these resources. Recent studies that have utilized neural networks to assist in developing predictive models of scenic beauty that have typically utilized linear regression techniques have found limited success. The goal of this research is to compare NN's with linear regression models to determine their efficiency predictive capability for assessing near view scenic beauty in the Cedar City District of the Dixie National forest (DNF). Results of this study strongly conclude that neural networks are consistently better predictors of near view scenic beauty in spruce/fir dominated forests than hierarchical linear regression models.

In some cases, preservation priorities and recommendations are based on specific vegetation communities. One example is Fremont Cottonwood-Goodding Willow forests within Pima County, Arizona, which are regarded as critical habitat and protected by the Sonoran Desert Conservation Plan. However, a prioritized system based on conditions within Fremont Cottonwood-Goodding Willow patches may afford greater flexibility to land managers, including selective or incremental preservation, which could accommodate funding challenges. This investigation assessed patches in three watercourses within Tucson, Arizona, and addressed the following questions: Are Fremont Cottonwood-Goodding Willow patches exhibiting characteristics related to vigor or decline? Are there significant relationships between patch vigor and channel variables? On-site assessment addressed Fremont Cottonwood-Goodding Willow patch characteristics and channel variables. Significant relationships were found between vigor and proximity of primary flow, channel width, and bank treatment. Vigor results were employed to develop recommendations designed to facilitate preservation decisions.

<p> Hybrid poplars are a short rotation woody crop grown for a variety of target markets including paper pulp, saw timber, and biofuels in the Pacific Northwest. Development of pest control strategies within hybrid poplar plantations over the last several decades has focused on controlling foliar feeding herbivores and wood boring pests, and has overlooked the epigeal arthropod community. Understanding this unstudied suite of organisms would allow pest managers to better evaluate the impact their management strategies have on the poplar agroecosystem. Qualitative surveys of the arthropod communities in hybrid poplar plantations and nearby native habitats demonstrated that a greater arthropod diversity persists in the surrounding native areas. Additionally, the poplar plantation's epigeal arthropod community was composed of species found within sampled native areas. </p><p> Historically poplar research focused on protecting trees in the years following establishment through harvest from emerging pests while discounting cutting mortality by replanting areas of failure. Describing unrooted cutting transplant morality and distribution within newly established planting block could provide a risk assessment tool that growers could utilize to evaluate their potential crop loss. It was determined through the examination of damaged cuttings that several pests were responsible for diminishing establishment success. Identification of these risks led to the development of a management strategy to reduce mortality in newly planted areas. Soaking cuttings in imidacloprid for 48 hrs provided superior herbivore protection for unrooted cuttings until root formation allowed for uptake from chemigation treatments. </p><p> An additional study was motivated by the increased concern in growing `clear wood' as poplar has migrated from pulp to saw timber. The accompanying renewed interest in reducing insect galleries in mature trees led to the exploration of deploying a mass trapping, or trap out, effort to reduce populations of <i> Prionoxystus robiniae</i> (Lepidoptera Cossidae) in specific areas of a hybrid poplar plantation. We show that a trap out effort of roughly 5 pheromone-baited traps/ha decimated <i>P. robiniae</i> populations in treated areas throughout the trap out effort and three years post application.</p>

Increasing levels of atmospheric CO2 threaten to change the earth's climate and diversity in numerous adverse ways. This thesis explores aspects of two potential types of terrestrial sinks in East Texas, plantation rotation management and reforestation. I used a simple method of employing government GIS and tabular data for calculating and visualizing the size of those sinks, which could store an additional 2.3 to 98 million Mg C aboveground. The uncertainty of these values is high because of data inadequacies and also uncertainty about future land use trends. The mitigative powers of these sinks are discussed, as is their potential application in newly forming carbon credit programs such as the Chicago Climate Exchange.

<p> Butternut (<i>Juglans cinerea</i> L.), or white walnut, has suffered large population declines in the past half-century due to poor regeneration and mortality caused by an introduced fungus, <i>Ophiognomonia clavigignenti-juglandacearum </i> (Nair, Kostichka &amp; Kuntz) Broders &amp; Boland. This fungus causes branch and trunk cankers that can coalesce to girdle adult trees. Chapter 1 provides background information on butternut and butternut canker. We used next-generation sequencing to identify new nuclear DNA markers for butternut and Japanese walnut, a congener with which butternut readily hybridizes. We also examined the alignment of SSR repeat sequences in butternut and Japanese walnut with similar sequences from other angiosperms in public sequence databases. The methods used and results obtained in this process are detailed in Chapter 2. Chapter 3 summarizes an investigation of the environmental and genetic factors contributing to canker disease incidence, severity, and mortality in a large (n=113) population of butternut in southern Wisconsin and two other populations of butternut, one near the main study site in southern Wisconsin and another in the Great Smoky Mountains National Park. We present evidence for weak correlations of genetic similarity and phenotypic similarity for several disease traits, parentage analysis of regeneration in the smaller Wisconsin population, and evidence for significant microsite influences on butternut mortality over an 11-year period in the large Slocum's Woods butternut population.</p>

<p> What drives invasive species success? My research consists of four studies aiming to answer this question for <i>Ligustrum sinense</i>. The four projects are: (1) Synthesis of invasion literature within passenger-driver-backseat driver frameworks; (2) hydrochory investigation of water as a dispersal mechanism for invasion; (3) ecohydrology investigation of inundation effects on seed viability of <i>L. sinense</i>; (4) dendrochronology study of the effects of stream channelization and <i>L. sinense</i> invasion on bottomland oak tree growth. Results suggest that <i>L. sinense</i> initially invaded habitats that were hydrologically altered, resulting in drier conditions and a "novel niche." Dispersal <i>via</i> hydrochory allowed <i>L. sinense</i> to quickly colonize the novel niches. Once established, <i>L. sinense</i> competed with native oak species contributing to reduced growth rates, an "invasion meltdown." Control strategies should aim to remove <i>L. sinense</i> and return natural hydrologic regimes, or should consist of human-assisted re-establishment of native species that can thrive in altered conditions.</p>

<p> Physical evidence of past fires, left in the form of cambial scars, suggests that low and moderate intensity fires have burned periodically for centuries in the coast redwood (<i>Sequoia sempervirens</i>) forest in California's central coast bioregion. These fires may have played an important role in shaping stand age structure and composition. Nonetheless, the ecological role of fire in shaping successional processes in the redwood ecosystem is not well understood. The extent to which both aboriginal and more recent burning practices have affected the central coast landscape is also uncertain. Standard dendrochronology techniques were used to reconstruct and analyze the fire history of the coast redwood forest in the Santa Cruz Mountains based on the fire scar record. Three hundred and seventy-three fire scars were identified in 70 cross-sections that were removed from redwood stumps, downed logs, and trees in select locations between Davenport and A&ntilde;o Nuevo, California. The earliest recorded fire occurred in 1352 and the most recent in 2009. The grand mean fire return interval (FRI) for single trees (point) was 60.6 years, and the median FRI was 40.1 years. Fire scars were found most frequently in the dormant and latewood portions of the annual growth rings, signifying that fires tended to occur in the late summer and fall. A high degree of variability in the data set suggests that cultural burning practices occurred on fluctuating temporal and spatial scales.</p>

<p> This study characterizes the experience of five states that have chosen to pursue third party sustainable forest certification of publicly owned lands using the principles and criteria of the Forest Stewardship Council (FSC). Studying the impact of FSC certification on Minnesota, Wisconsin, Michigan, Ohio, and Pennsylvania may provide the Colorado State Forest Service and other forest stakeholders with an improved understanding of the potential impact of FSC certification of Colorado's public forests. This issue is especially pertinent to Colorado green builders who are attempting to acquire structural lumber from sustainably managed forests within a 500 mile (805 km) area of the construction site, as prescribed by US Green Build Council's (USGBC) Leadership in Environmental and Energy Design (LEED) standards. As there are no FSC certified forests in Colorado or neighboring states, sustainable builders cannot comply with some pertinent green building standards. Additionally, It is intended that this study will support sustainable forest policy studies and facilitate continuing research on the impact of FSC certification of Colorado public forests.</p>

Thesis (Ph.D.)--Indiana University, School of Public Environmental Affairs and Dept. of Political Science, 2007. / Source: Dissertation Abstracts International, Volume: 68-05, Section: A, page: 2152. Adviser: Elinor Ostrom. "Title from dissertation home page (viewed Jan. 12, 2008)."

Thesis (Ph.D.)--Indiana University, School of Public and Environmental Affairs and the Dept. of Political Science, 2008. / Title from PDF t.p. (viewed on Oct. 6, 2009). Source: Dissertation Abstracts International, Volume: 70-02, Section: B, page: 0760. Adviser: Elinor Ostrom.