Thesis (M.S.), Natural Resources, Environmental Education, University of Wisconsin--Stevens Point, 2004. / Includes bibliographical references (p. 109-112).

Thesis (MFA)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Ronald Tobias. Includes bibliographical references (leaves 30-31).

Thesis (Ph. D.)--University of Chicago, Dept. of History, Dec. 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 29, 2006) Vita. Includes bibliographical references.

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Freshwater ostracods are potentially useful for environmental monitoring and, since their calcified valves may be preserved in lake sediments, are also valuable in palaeolimnological studies of environmental pollution such as eutrophication and surface water acidification. To establish a data-base of ostracod ecology, biannual survey work in 1989-1990 was performed in 75 lakes and tarns of a wide range of physico-chemical characteristics in the Lake District in Cumbria, ranging from large eutrophic lakes such as Windermere and Ullswater to tiny, upland acidic tarns. pH ranged from 4.3 (Black Pool) to 8.0 (Browns Tarn). Littoral margin samples were taken from all 75 sites and yielded 31 ostracod species, of which 8 were new to the Lake District fauna. The collection of multiple littoral samples from two sites demonstrated that a single sample produced an adequate faunal representation if it encompassed a variety of microhabitats. Statistical analysis, incorporating a multistage, multivariate technique, has shown that 18 species make up over 99% of the data set, and that 5 species, Cvpria ophthalmica, Cvclocypris ovum. Metacvpris cordata. Candona Candida and Cvpridopsis vidua. dominate the community in 71% of the sites containing ostracods, forming eight distinct assemblage groups. No ostracods were found in 13 of the 75 sites, 11 of which were acidic, having a pH of below 5.7. Equations were derived to predict both species distribution and diversity. Important predictors of community structures were shown to be pH, [Ca] 2+ , [Mg] 2+ , substrate, lake size and altitude. The equations were tested by further sampling of additional sites in the Lake District. Predictions of total species number and density generally provided an excellent fit to the observed data, although individual species predictions were poorer, especially in alkaline conditions. Substrate was not included in the analysis, due to quantitative difficulties, but this factor must be included in future predictive models as it was shown to be an important parameter in determining distribution. Deep-water sampling was carried out in 6 lakes. 10 species were collected, including Candona necrlecta, which was absent in the littoral samples. 9 species contributed to over 99% of the data set, and 2, Cypria ophthalmica and Candona Candida dominated the community in 75% of the sites containing ostracods. Community structure was predominantly determined by water depth (together with the associated temperature effect) and substrate. The sex ratio of Cyclocvpris ovum was shown be biased towards the female only at high alkalinities. Other species had sex ratios biased towards the male or female, the values independent of water quality. Large, swimming ostracod species were absent in sites containing fish. A series of laboratory experiments using three species of Ostracoda, (Cvpria ophthalmica. Cvpricercus fuscatus. and Eucvpris virens), and a predator (Gasterosteus aculeatus) correlated increasing ostracod size with an increased rate of predation, suggesting that predation could limit ostracod distribution. From the results of principal component analysis, it was concluded that the main characteristics that chemically differentiate the sites are calcium, magnesium, hydrogen and sodium ion concentrations. Toxicity tests were used to expose selected species to a wide range of calcium, magnesium, sodium and aluminium concentrations, at both neutral and acidic pH levels. Aluminium was selected as it has been highlighted as a major factor in the toxicity of acid waters. All species tolerated a wider spectrum of ionic concentrations than those in which they were recorded in the field, although the order of species survival in the experiments was similar to that found in the Lake District. It is suggested that whilst adult Ostracoda do not suffer from the acute toxicity of pH or aluminium, they may be unable to successfully reproduce in harsh environmental conditions. The waters of the English Lake District are not particularly species-rich due primarily to low alkalinity and low levels of dissolved cations, but also because they are cold. Only in small, ion-enriched pools is ostracod density sufficiently high to warrant their consideration as important detritivorous contributors in the cycling of nutrients. The Lake District fauna is compared with those recorded in other parts of Britain and Europe.

The flora of Crete in its multifarious micro-landscapes offers the possibility of selecting native species with high ornamental value for use in urban landscapes and commercial horticulture. To assess this potential eight species were selected: Staehelina petiolata, Ptilostemon chamaepence, Otanthus maritimus, Prasium majus, Convolvulus dorycnium, Campanula pelviformis, Sternbergia sicula and Colchicum macrophyllum. The biological cycle in situ, sexual and asexual propagation as well as their cultural requirements and adaptability in urban landscape were studied. In addition to identifying the light and temperature requirements for seed germination of the species, Other factors were important including after-ripening for P. chamaepence and S. petiolata, scarification for P. majus and C. dorycnium and imbibition in 20°C for C macrophyllum and S. sicula. Propagation by stem cuttings was influenced by mist, addition of IBA, the season and the substrates. IBA solutions at 4000, 2000 ppm and 2000 ppm in powder promoted on rooting of S. petiolata, P. chamaepence and P. majus stem tip cuttings with the highest rooting level of 50, 70 and 72%, respectively, while both IBA at 0 or 2000 ppm on Otanthus maritimus produced 100% rooting. Best substrates were peat-moss+vermiculite, vermiculite, sand and vermiculite and best seasons autumn, spring or late autumn, early summer, and spring for Staehelina. Ptilostemon, Otanthus and Prasium, respectively. Cross-cutting and BA on the base of Sternbergia sicula increased the bulblets from 1-3.5 to 12.8 and 13.5 per bulb yearly, respectively. Colchicum macrophyllum had a very low asexual reproductive activity producing one corn per year. The wounding of the replacement bud stimulated development of the reserve bud so that each corm could produce two or more cormlets. Morphogenesis was achieved in vitro by the affect of BA; callogenesis and rhizogenesis by NAA, and rhizogenesis by IBA on S. petiolata and P. chamaepence seedlings. Adventitious bulblets and plantlets formed on scales and clumps of shoots of S. sicula by the addition of BA and NAA producing over 20 bulblets per bulb. 2,4-D, BA, NAA and combinations produced callus, shoots and new corms on buds of C. macrophyllum. All studied species were established successfully in pots and in an urban landscape. The ornamental characteristics and use of eight species was determined and a master plan was designed using indigenous plants of Crete.

Widely distributed species typically exhibit variation in various aspects of their ecology throughout their range. Such variation offers opportunities for fundamental studies in evolution, including local adaptation, biogeographic rules, distributional limits, and speciation. Geographic variation also limits our ability to extrapolate from one population to another, making site-specific knowledge of ecology essential for wildlife management and conservation. I studied the natural history of Common Gartersnakes (Thamnophis sirtalis) at two sites in east-central British Columbia, where active seasons are short and cool. I used opportunistic sampling of snakes to study general features of their ecology and radiotelemetry to study movements and habitat selection, including hibernating sites. In September, snakes move from summer habitats to hibernating sites and then emerge from hibernation in April or May. Adult female T. sirtalis overwintered with 0 to 16 other adults in inconspicuous underground hollows, typically in forested habitats, near water and/or coarse woody debris; this is distinct from the large-scale communal hibernation seen in other northern populations. Hibernacula were typically distant from summer habitat (mean = 1485 ± 937 m SD, n = 8, range = 148-2657 m). Under the assumption that snakes exhibit site fidelity to hibernacula in consecutive years, I estimated the cumulative distance moved over the entire active season to be 7011 ± 3756 m SD (n = 9, range = 3510-15015 m). Gravid female snakes moved at significantly lower rates, followed more tortuous paths, and inhabited areas that were more open-canopied than their nongravid counterparts (n = 13). Nongravid snakes used locations with a higher percentage of ground cover than gravid snakes. Mating occurred in early spring near the hibernacula and parturition in early to mid August in summer habitat; litter size ranged from 3 to 25 and was not significantly correlated with the size of the female. Adult snakes preyed exclusively on adult Western Toads (Anaxyrus boreas) and juvenile snakes fed on leeches and metamorphosing toads. Through the identification of migratory routes, relevant summer and winter habitat characteristics, and hibernation sites, my study contributes to the protection and conservation of northern reptiles, which are particularly vulnerable to population declines compared to southern populations due to the restrictive cold climate. / Graduate

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