<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>

<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.

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.

<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>

This ethnographic case study of eight environmental teacher educators who collaborated in a four-state watershed education partnership was focused on processes of social constructions of region and regional partnership. Participant observation in meetings, interviews, and spatial representations were used as data for the eleven-month study. Spatial representations at two intervals were analyzed for documentation of conceptual change. A metaphorical model was used as the interpretive frame for analysis of interview and partnership meeting discourse features. Participants identified central features of place, diversity, and scale as they elaborated upon their sub-watershed valley regions as "home." Participants identified experiential learning as the foundation for watershed education, and reported that grounded experience was their own most essential way of knowing the watershed. The participants valued collaboration, networking, learning about one another's work, and the opportunity to make professional connections as benefits of partnership. In an examination of discourses of "self" and "the environment," analysis of partnership discourse strategies yielded evidence of prosodic phenomena such as raising questions and laughter as means of maintaining synchrony and coherence in meetings. Over the study period, the participants' spatial representations demonstrated tensions between political and bioregional boundaries and growing similarity across representations of the partnership. Issues of support for multistate regional partnerships were considered. Conclusions were that cultural and folk concepts of region are useful in determining scale to inform watershed education policy initiatives and implementation. In partnership meetings, democratic practices were considered most practical for "getting something done." Implications for education included expanding applications of metacognitive approaches, a focus on experiential learning in watershed education, and the place of "place" as an interdisciplinary educational focus. Finding a cultural taboo on conflict, the researcher recommends further development of curriculum environmental conflict resolution, and calls for intergenerational community watershed councils trained in conflict resolution and mediation as foci for regional watershed education efforts.

The socio-spatial distribution of hazardous waste sites in the United States closely resembles the distribution of industry more generally. An understanding of these spatial patterns requires considering the positive and negative externalities of residence near noxious industrial locations and variations across social groups in the ability to externalize costs. In contrast to the central thesis of the environmental justice framework, there is no evidence of a widespread, inequitable distribution of hazardous waste sites that disproportionately burdens poor and minority neighborhoods. Tract level analysis of national data and data on large metropolitan areas for various types of industrial and environmentally sensitive land uses provides consistent evidence that hazardous waste sites are located in industrial areas. As a general trend, hazardous waste sites tend to be located in white, working class neighborhoods in which larger percentages of persons with lower skills and persons employed in industrial jobs and industries reside, and in which access to modes of mass transportation is readily available. Differences between Hispanics and blacks in the empirical findings in which Hispanics are disproportionately represented in tracts hosting certain types of hazardous waste sites, particularly in metropolitan settings, are attributed to their different migratory histories and experiences with residential segregation and labor market discrimination. The dense residential concentration of blacks in areas with little or diminishing economic activity and blacks' less successful competition with Hispanics over the shrinking base of manufacturing jobs are factors considered to contribute to the lower representation of blacks in noxious industrial locations. The more frequent incidence of Hispanic proximity to noxious industrial locations is described as being reflective of the greater integration of Hispanics in the industrial labor market. The heterogeneity of sites proved to be a salient factor with distributional effects across regions and across different racial and ethnic categories. Older abandoned sites were found in larger numbers in older Northern MSAs. Abandoned sites appeared to be more readily avoided by non-minority whites, particularly when these sites were not the only locations of industrial employment in the larger area.