O conhecimento e compreensão dos processos que regem a dinâmica das comunidades são alguns dos objetivos da ecologia. Com o crescente impacto gerado pelas ações antrópicas e em particular a existência de mudanças climáticas globais, estudos para entender a distribuição de comunidades se tornam mais necessários. Especialmente no Brasil, que mesmo com o aumento considerável de pesquisas, os costões rochosos ainda são ambientes pouco investigados, o que dificulta a detecção de mudanças na estrutura dessas comunidades devido a ausência de observações prévias. No entanto, poucos são os projetos em costões rochosos que visam detectar estas alterações ao longo do tempo e estão ainda em sua fase inicial. Como alternativa, estudos descritivos realizados em décadas prévias se constituem em uma linha de base e fonte de comparação para que seja determinado o status atual da comunidade. Com base em dados pretéritos da década de 1980, esse estudo tem como objetivo a comparação temporal da estrutura da comunidade bentônica do costão à direita da Praia de Itaguá em Ubatuba, município do litoral norte do Estado de São Paulo. As coletas foram feitas no mesmo local e utilizando o mesmo delineamento experimental durante o inverno de 2017. Foram utilizadas duas estratégias: a primeira para determinação do padrão de zonação, com amostragens ao longo de transecção vertical desde o supralitoral até a parte inferior do médiolitoral, utilizando-se elementos amostrais quadrados de 50 x 50cm. Para determinar a composição de espécies e repartição espacial na faixa inferior do mediolitoral, foram aleatorizados elementos amostrais quadrados de 20 x 20cm. Em ambos os casos foram avaliados o recobrimento percentual das espécies dominantes e no primeiro, a largura das faixas de organismos dominantes. ANOVA one-way foi aplicada, sendo os dados considerados paramétricos, de forma a sustentar a hipótese estabelecida de que houve alterações significativas na estrutura da comunidade. Além disto, foi acrescentada ao estudo uma estação de monitoramento de longo prazo seguindo as diretrizes do protocolo da Rede de Monitoramento de Habitats Bentônicos (ReBentos) no mesmo local onde a transecção vertical foi amostrada para comparação. As amostragens foram realizadas durante o verão e inverno de 2017, com 3 réplicas por período, onde os elementos amostrais foram distribuídos em 3 faixas (superior, intermediária e inferior) do mediolitoral, com 5 elementos amostrais de 10 x 10cm na faixa superior e 5 elementos amostrais de 20 x 20cm nas faixas intermediária e inferior, além de 5 transectos verticais para medir a largura de faixa horizontal dos organimos. Análises multivariadas (PERMANOVA two-way, PCA, Cluster e nMDS) foram aplicadas para os dados, considerados não paramétricos. Tanto os dados de comparação quanto os da estação de monitoramento apontaram uma alteração principalmente na distribuição e percentual de cobertura de Pterocladiella capilácea que aparentemente diminuiu, enquanto a alga Aglaothamnion uruguayense apresenta um aumento considerável desses parâmetros se comparado aos dados encontrados em trabalhos anteriores / To know and understand the processes that rule community dynamics are some of the Ecology objectives. As the impacts caused by anthropic activities are increasing, particularly the global climate changes, studies about the distribution of communities have become important. In Brazil, even though the increase of researches, rocky shores are still little studied, impairing the detection of changes in communities´ structure due to the lack of previous observations. However, there are few rocky shores projects aiming to detect those changes in communities through the time and they are still at an early stage. As an alternative, descriptive studies from past decades are a good baseline and source of comparison to establish the actual stage of a community. In this sense, according to data from the 80s, we aim to make a temporal comparison of the benthic community of the right rocky shore of the Itaguá Beach in Ubatuba city in the north coast of São Paulo State. We collected data during the winter of 2017 in the same place and using the same sample design of the comparative study. In this study, we used two strategies: (1) square samples of 50 x 50 cm were placed along the vertical transection from the upper intertidal to the inferior part of the middle intertidal to determine the zonation pattern, and (2) square samples of 20 x 20 cm were randomized to determine the species composition and the spatial division in the inferior part of the middle intertidal. In both cases, the percentage coating of dominant species was evaluated, as well as the band width of dominant organisms of the first strategy. We used ANOVA one-way for data analysis (parametric data), testing the hypothesis that there are significant changes in the community´s structure. Moreover, a long-term monitoring station, following the protocol guidelines of Benthic Habitats Monitoring Net (ReBentos) in the same place of the vertical transection sampled for comparison. We sampled during the summer and winter of 2017, with three replicas by period and distributed along three bands (superior, middle and inferior) of middle intertidal. We distributed 5 samples of 10 x 10 cm in the superior band and 5 of 20 x 20 cm in the middle and inferior bands, as well as 5 vertical transects to measure the width of the horizontal band of organisms. We considered non-parametric data and used multivariate (PERMANOVA two-way, PCA, Cluster and nMDS) analysis. The findings highlight an alteration, mainly in the distribution and percentage coating of Pterocladiella capillacea that apparently decreased while Aglaothamnion uruguayense showed a great increase of those parameters, according to the comparison with previous data

Thesis (D. Min.)--McCormick Theological Seminary, 2002. / Includes bibliographical references (leaves 41-43).

Brook trout invasion into bull trout streams is variable, and likely influenced by a suite of biotic and abiotic factors. Field observations revealed that brook trout dominated the fish community over bull trout in warmer sites that had undercut banks; in contrast, bull trout dominated in colder sites that had a high amount of large substrate cover, and where alternate non-native species were present. Laboratory studies of competition between the two species revealed that bull trout use a scramble foraging tactic, whereas brook trout use a territorial tactic. Bull trout outcompeted brook trout when fish density was low and habitat complexity was high, as this scenario reduced the effectiveness of the aggressive territorial foraging strategy of brook trout. Bull trout from a migratory population competed more successfully against brook trout and had higher rates of oxygen consumption than those from a resident population. This combined field-lab study points to some of the abiotic and biotic factors that affect competition between the two species, and may influence the outcome of brook trout invasion into bull trout streams. / xiv, 184 leaves : ill. ; 29 cm

A modelling approach focused on snow hydrology was developed and applied to project future changes in spring streamflow volumes in the St. Mary River headwaters basin, Montana. A spatially distributed, physically-based, hydrometeorological and snow mass balance model was refined and used to produce snow water equivalent (SWE) and rainfall surfaces for the study watershed. Snowmelt runoff (SR) and effective rainfall runoff (RR) volumes were compiled for the 1961-2004 historical period. A statistical regression model was developed linking spring streamflow volume (QS) at Babb, Montana to the SR and RR modelled data. The modelling results indicated that SR explained 70% of the variability in QS while RR explained another 9%. The model was applied to climate change scenarios representing the expected range of future change to produce annual QS for the period 2010-2099. Compared to the base period (1961-1990), average QS change ranged from -3% to -12% for the 2020s period. Percent changes increased to between -25% and -32% for the 2050s, and -38% and -55% for the 2080s. Decreases in QS also accompanied substantial advances in the onset of spring snowmelt. Whereas the spring pulse onset on average occurred on April 8 for the base period, it occurred 36 to 50 days earlier during the 2080s. The findings suggest that increasing precipitation will not compensate for the effects of increasing temperature in watershed SWE and associated spring runoff generation. There are implications for stakeholder interests related to ecosystems, the irrigation industry, and recreation. / xii, 136 leaves : ill. ; 28 cm. --

Thesis (M.S.)--University of Montana, 2004. / Typescript. Additional information available on author's web site. Includes bibliographical references (leaves 138-142).

Plant macrofossils and pollen from six small basins in western Colorado are used to trace the history of vegetation and climate over the last 15,000 years. The late-glacial upper timberline was 2800 m, and sparse krummholz Picea grew up to 3200 m. Summer temperatures were 3° to 5°C cooler than today. The late Pleistocene climate was influenced by winter storms from the Pacific. Precipitation shifted to a summer-dominated pattern by at least 9000 yr B.P. with the development of the summer monsoon. Plant fossils from bogs and lakes located near modern ecotones track the elevations of the temperature-controlled upper timberline and the moisture-controlled lower forest through the Holocene. Between 9000 and 4000 yr B.P., the Picea engelmannii-Abies lasiocarpa forest covered a broader elevational range, with upper timberline 200-300 m higher than today. Mean annual temperatures were 1.8°C warmer, and mean summer temperatures were 2.1°C warmer, than today. Temperatures were still about 1°C warmer prior to 2000 yr B.P. The lower limits of the montane and subalpine forests were 100-200 m below their modern elevations from 9000-4000 yr B.P. Mean annual precipitation was 50-100 mm greater. By 2600 yr B.P. the modern lower forest borders were established. Modern pollen dispersal, transportation, and deposition was sampled in atmospheric collectors, moss polsters, and surface lake sediments. Annual accumulation rates range between 1000 and 5000 grains cm⁻²yr⁻¹. Modern influx (grains cm⁻²yr⁻¹)averages: 1100 in alpine tundra, 2700 in the subalpine forest, 3400 in the montane forest, and 200 in shrub steppe. Pollen spectra in atmospheric traps and moss polsters reflect local vegetation, and provide effective modern analogs for pollen accumulation in peat bogs. In forested environments 80-90% of the pollen deposition in small lakes (< 5 ha) with no inflowing streams comes from atmospheric input. Pollen spectra in open vegetation are distorted by pollen from other vegetation types. At least half of the pollen deposition in small alpine lakes comes from taxa growing up to 1500 m lower in elevation.

A theoretical framework is developed for incorporating class conflict dynamics into accumulation theories of labor market segmentation by analyzing the transaction costs of conflict under varying conditions of economic structure and power resources. The theory has the "bottom up" perspective developed in the "new social history." Skill is treated as a status for which workers struggle and internal labor market hierarchies are considered products of the conflicting strategies between capital and labor. Split-labor market theory is also discussed as a method for explaining why workers discriminate. This theory is amended to distinguish between market and class interests of workers, and to take into account the self-perpetuating economic effects of racist discourse. My historical analysis of the metal-mining industry emphasizes the formation of ethnically stratified segments of the labor market in which Chinese and Mexican workers were denied access to the craft-internal labor market for skilled workers. Competition over mining claims under the threat of takeover by mining companies created ethnic antagonism between Chinese and white independent petty-commodity miners. Discrimination by the white independent miners crowded the Chinese into the labor market, which reduced Chinese wages, and induced conflict between white and Chinese wage workers in the company-mines. Ethnic antagonism in combination with intense class struggle produced a segregated labor market between Mexican miners and Anglo supervisors during the initial proletarianization of the mines. Mexican miners were later displaced by Cornish miners who developed a segregated craft-internal labor market. Analysis of the labor process shows that mechanization initially facilitated the struggle by Cornish miners for a skilled status, contrary to homogenization expectations. Mexican miners were relegated to unskilled manual positions.

Seventeen glacially sheared stumps in growth position and abundant detrital wood fragments were exposed by stream avulsion at the terminus of the Saskatchewan Glacier in 1999. The stumps lay buried beneath the glacier and over 5 m of glacial sediment until historical recession and stream incision exposed the 225- to 262-year-old stand of subalpine fir, Englemann spruce and whitebark pine trees. Crossdating and construction of two radiocarbon-controlled floating tree-ring chronologies showed that all the subfossil stumps and boles exposed at this location were killed during a Neoglacial advance of the Saskatchewan Glacier 2,910 ± 60 to 2,730 ± 60 ¹⁴C years B.P. These findings support the Peyto Advance as a regional glaciological response to changing mass balance conditions.

Increasing visitation to national parks and the resulting resource impact has caused many park administrators to implement restrictive use management strategies. Though it seems clear that the resource has benefited from these use restrictions, little research has been done to determine their effect on the visitor. The goal of this study was to provide information to help guide the administrators of Rocky Mountain National Park in evaluating current use management actions and developing new ones in the future to both satisfactorily meet the protection needs of the resource and protect the quality of the visitor experience. Frontcountry campers were surveyed to determine awareness and attitudes about current and possible use management actions, perceptions of national park management purpose and challenges, and socio-demographic information. Respondents favored the majority of current use management actions, but were opposed to strongly restrictive actions considered as a possibility in the future.

Weather, how we tangibly engage with climate in our everyday lives, is a central underpinning to life in Canada and around the world. This thesis investigates relating to weather through a focused exploration of wind in the everyday lives of fire lookout observers in the Canadian Rocky Mountains. Stitching together approaches from anthropology, phenomenology and mountain meteorology, it brings to bear insights on coexisting with weather changes through an understanding of lived mountain climates. Perched atop the front ranges of the Alberta Rocky Mountains are located a string of mountain fire lookouts. Tasked with discerning and detecting smoke plumes that may signal the start of a wildfire, lookout observers, who inhabit these remote lookout places for five to six months of the year, are attentive to the wind’s effect on visibility, its role in wildfire processes, and as a force to contend with in their daily lives on the lookout. Through participant observation, interviews and photo elicitation, I draw on fire lookout observers’ past and present experiences of wind, and its role in larger weather processes. With many lookout observers returning to their posts season after season, the breadth and depth of their experience stretches over three decades. Over the course of a summer’s fieldwork, I hiked in, and at times lived with, lookout observers. Walking, as a contemplative research practice, continued beyond the field and into analysis, engaging in a process I call ambulant listening as an alternative to transcribing interviews verbatim. This involved walking and listening to interviews multiple times, with notes later drawn out visually using mind maps. Through this process, I learned that wind stirs up much more than simply considering air in motion. Entwined in a variety of multi-sensory engagements, wind touches on broader themes of awareness, encounter and wonder that emerge as weather consciousness. This study offers a rare lens into a way of life that has been increasingly shuttered across Canada and around the world, while at the same time exemplifying ways of being and knowing weather inherent to coexisting with increasingly uncertain and unpredictable weather patterns in the midst of climate change. / Graduate / 0326, 0334,0314,0344 / kristen.walsh@hotmail.com