<p> This study of the vegetation of the 100,000-acre Connecticut Tract in western New York examines the presettlement characteristics of the forest, including the tree species composition, tree density, and wetland extent. Presettlement vegetation studies add to what is known about the forests of this region before European settlement in the early 1800s brought widespread changes to these forests. The ecological data in original private land surveys from 1811 were transcribed and then analyzed using ArcGIS and IDRISI GIS software. The surveys contained both witness tree data and line descriptions, which were analyzed for species composition and community type and were compared with Forest Inventory and Analysis (FIA) data about the contemporary forest in the study area. The community type results together with surveyor notes were used to extrapolate wetland coverage, which was compared with the 2006 National Wetlands Inventory Database.</p><p> This study fills in missing historical data between the two largest land purchases in western New York and examines forest composition at a finer-grained scale than surveys of those land purchases. Comparing past and present vegetation clarifies past causes of temporal and spatial variability and provides a reference point for land managers who need to understand the effects of land-use history for ongoing restoration efforts.</p>

Thesis (M.A.) - Carleton University, 2009. / Includes bibliographical references (p.122-129). Also available in electronic format on the Internet.

Thesis (M.A.) - Carleton University, 2009. / Includes bibliographical references (p. 125-137). Also available in electronic format on the Internet.

<p>Necessary for the diversity and survival of most terrestrial plants, arbuscular mycorrhizae (AMF) are fungi that form mutualistic symbiotic relationships with approximately 90 percent of terrestrial plant families. While the biodiversity and abundance of plants and animals have received much attention, these patterns for the belowground organisms on which they rely, such as AMF, remain poorly understood. While studies have found indications that AMF are fundamental to ecosystem structure and function, relatively few of these studies have been conducted in situ. In their ability to accommodate the complexity found in natural ecosystems, in situ studies may be vital in providing information relevant to the restoration and conservation of ecosystems. This thesis sought to explore in situ how AMF diversity and root colonization changed across ecosystems along an elevation gradient in Southern California. The findings indicate that certain soil parameters may be especially influential and that intra-species competition may play a role in AMF root colonization.

Thesis (Ed. D.)--University of Kentucky, 1992. / Abstract ([2] leaves) bound with copy. Vita. Includes bibliographical references (leaves 145-162).

Thesis (Ph. D.)--Syracuse University, 2005. / "Publication number AAT 3186475."

The objective of this study is to test the hypothesis that the Hazen Plateau and North Coast of Ellesmere Island, Nunavut, Canada are two environmentally-sensitive area where relatively slight changes in meteorological conditions can lead to dramatic changes in snow and firn extent in the short-term, and to a systematic shift in the regional glaciation level in the long-term. The study represents an integrated program of field measurements, data analysis, and data modeling to determine the nature of the land-atmosphere-snow and ice interactions and to quantify the sensitivity of snow and ice cover on the Hazen Plateau and along the North Coast to climate change. The glaciers along the northern coast of Ellesmere Island, specifically the Ward Hunt Ice Rise and Ice Shelf, are today not in equilibrium with climatic conditions and will disappear at some point in the near future unless climatic conditions deteriorate dramatically. Dynamical stresses related to wind, wave, and tidal action may further accelerate this process, as open water conditions on the Arctic Ocean become more prevalent. Mass losses occurring at the bottom of the floating ice shelf are more significant in terms of its stability than the associated surface mass losses. The Hazen Plateau ice caps have experienced considerable marginal recession and significant overall mass loss since at least 1959. The sensitivity of these ice caps to changes in climate is enhanced by the low amounts of winter snow accumulation, the absence of iceflow, and their small vertical relief. They are also out-of-equilibrium with modern climate and considered to be relicts of past climatic conditions with reduced summer melt and/or increased snowfall.

This study sketches out the ways in which a candidate talks to voters. In modern presidential campaigning far too much of the focus is upon the broadcast media and their role in determining what gets filtered through to the citizenry. This is not a study of the effects of the mass media. No attempt is made here to dispute or confirm the effects of television upon the political process. Instead, this is a study of public speaking--the relatively direct interaction between the candidate and the potential voter. The work addresses a theoretical concern about creating a public space where political communication can occur. The study is divided into rhetorical analyses of key elements of the political arena that candidates from both parties constructed. The first chapter outlines the mythic rhetoric of citizen participation that characterizes this election in New Hampshire and outlines how the press attempts to locate representations of that participation. The following three chapters treat separately key elements of the public sphere by investigating where the candidates spoke and to whom, outlining the choices of formats for these appearances, and describing the sorts of language and image strategies employed by the candidates. A fifth major chapter depicts alternate constructions of public space that a handful of candidates used to deviate from the general patterns. Although this study is focused upon a single primary election and offers a clear historical record this is not the main purpose of the work. The analysis is spatially oriented and is meant to offer a geographic record of how the campaign was shaped by collective and individual conceptions of a public stage. To accomplish this purpose a rhetorical analysis of the political arena is used to create a "map" of the 1988 New Hampshire primary. This map details where the candidates chose to speak, to whom, in what manner, and with what language and images.

<p> Biological soil crusts are communities of bacteria, microfungi, algae, lichens, and/or bryophytes that colonize the surfaces of soils where other vegetation is sparse. Soil crust communities are best known from the world&rsquo;s arid and semiarid regions, including North America&rsquo;s hot and cool deserts, where they aid in soil stabilization and aggregation, reduce erosion, and contribute to nutrient inputs in the soil. Although a significant body of work has emerged on soil crust function in arid and semiarid environments, there is still much to be learned about their geographical distributions within and across different vegetation communities. Sagebrush shrublands and pinyon-juniper woodlands are common communities in the central Great Basin, but this region is under-studied with respect to biological crust composition and distribution. I collected data on soil pH and the cover of plant functional groups and biological soil crusts in sagebrush and pinyon-juniper zones in the Wassuk Range of western Nevada. Regression models revealed that in the shrublands, soil crusts associate negatively to rock cover and positively to moderately dense shrub canopy. In the woodlands, ground-cover of rocks and woody litter have a negative association with soil crusts. Sagebrush and pinyon-juniper communities are facing many stressors and undergoing changes in structure. My results offer a possible starting point for assessing how the biological crusts in these habitats might respond to these changes based on their current distributional controls. Future research should further explore the response of biological crusts to trajectories of change in the central Great Basin ecoregion.</p>

<p> Traditional spatial analysis and data mining methods fall short of extracting temporal information from data. This inability makes their use difficult to study changes and the associated mechanisms of many geographic phenomena of interest, for example, land-use. On the other hand, the growing availability of land-change data over multiple time intervals and longer time frames, often based on satellite imagery, presents to land-change study a great opportunity, given that this information can be effectively utilized. This methodological gap highlights the need to better understand the analytical challenges brought by temporal complexities, and to investigate alternative analytical frameworks that could handle those challenges. </p><p> This dissertation attempted to achieve three goals: 1) finding metrics to capture temporal trends, 2) dealing with temporally imprecise data due to constraints of frequency, duration, and starting time of data collection, and 3) handling variables with time-changing values. A simulated land-change dataset based on an agent-based model of residential development and an empirical dataset from two case study sites in San Diego and Tijuana were used for this investigation. </p><p> Results from the simulation dataset indicated that the survival function and the hazard function are important metrics to reveal temporal trends. In general the results of land-change analysis are sensitive to time frequency, in particular when time-dependent variables are also present. Longer duration benefits land-change analysis since longer durations contains more information. However, time-dependent variables with measures over a long period are more difficult for detection, which may pose a challenge. Starting time also affects the analytical results because the level of process uncertainty varies at different starting times. Findings from real world data mostly agree with those from computational data. Time dependent variables present a major challenge in land-change analysis, and survival analysis can better handle time-independent variables and thus better forecast urban growth.</p>