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No description available.

No description available.

No description available.

<p>In this project an aquatic field trip resource is developed for both elementary and secondary teachers to use in their classes and at a pond site. It uses the compulsory activity from the grade 11 general level environmental science course as a model. Abiotic factors are measured and water organisms are surveyed so that the water quality can be determined.</p> <p>This study evaluates the effectiveness of a field trip to a pond in meeting the Ministry of Education science course objectives and looks at evaluation methods for the purpose of improving the learning experience for students. A report is given of water quality parameters as presented to the community of teachers who would possibly be using the site and a questionnaire given to survey their reactions and ideas about this report. To assist teachers further, a list of resources to help with this unit was developed from material gathered as the project took form.</p> <p>To put the unit and its teaching into a provincial focus and to gain practical ideas that would make teaching and preparing for the field trip more successful, a survey was done outlining the programs of similar centres nearby. Unfortunately, low data sets of students in the course could not reliably yield any scientific conclusions. The reactions of students to the activity, the historical background to this type of educational activity, and the positive effect of this additional tool in teachers' professional toolkits (Miles, 1990, ), shows this a worthwhile activity to undertake.</p> <p>The project did allow development of a detailed guide to aquatic organisms that can be used by teachers wanting some assistance teaching this unit. With changes by the current government, this particular course will not be offered again after the '98/99 school year. Courses at the elementary level will find this information helpful. Courses at the secondary level are currently being developed that should include units where this resource could be used.</p> / Master's of Science in Teaching (MST)

<p>The acid-base and structural chemistry of freshwater dissolved organic matter (DOM) is known to vary with time and location. The purpose of this dissertation is to show how the chemical quality of DOM in temperate streams, wetlands and lakes of the Kejimkujik National Park area in central Nova Scotia varies over an annual cycle and how the changes in quality are related to DOM formation and diagenesis. New techniques were developed and used to better define the chemical quality DOM. A titration method described by Brassard et al. (1990) allowed the description of the acid-base characteristics of DOM. A reverse osmosis method is also described for the concentration of DOM without its fractionation to allow structural determination by ¹³C NMR of whole material. The results indicate that the chemical quality of DOM found in freshwaters is not similar to that found in soils. This difference suggests that interactions between soils, biology and hydrology modify the DOM in streams. A laboratory experiment suggests that the most likely pathway of DOM formation is the breakdown of plant structural material into aliphatic material with subsequent aromatic formation via semi-quinone and quinone. Comparison of incubation experiments with field results also shows that DOM acidity in natural water decreases with time caused by biological and chemical oxidative processes. Theoretical considerations indicate that the acidity of DOM does not follow the simple relationship suggested by Oliver et al. (1983) because of differences in source material and diagenetic processes, as well as the influence of inorganic cations and anions which until now have been assumed to be uncomplexed with organic matter.</p> / Doctor of Philosophy (PhD)

<p>A study evaluating the response of canopy transpiration (Ec) and growth rates to reduced water input, was conducted in a managed 70-year old planted temperate white pine (Pinus strobus L.) forest, in Southern Ontario, Canada from January to December 2009. In order to induce the drought, a 20m x 20m throughfall exclusion setup was established using interlocking aluminum troughs at a 3-inch slope. Throughfall was excluded from April 1st until July 3rd. During this period, 270mm of rainfall occurred (27% of annual precipitation) of which 90% was excluded. Sap flow velocity, soil moisture and soil temperature (at multiple depths) were measured continuously in both reference and drought plots. Dendrometer bands were also installed on all instrumented trees. Prior to enforced drought, adjacent plots showed slight variability in soil moisture while tree diameter and soil temperature did not show significant variability. Daily values of Ec from each plot ranged from 0 to 1.6 mm d-1 over the growing season (March-November) for the drought and reference plot respectively. The impact of the rainfall exclusion did not affect Ec until early June, 60 days after the drought was in place. Normalized values of Ec showed a 20% decrease from the drought trees compared to the reference. Cumulative growth rates between the two plots showed a net decrease in the drought trees of 42% from the reference and earlier termination of growth. However, the growing season Ec values were 174 mm y-l and 171 mm y-l for the drought and reference plot respectively. Currently, the effects of extreme drought<br />events on carbon and water balances in conifer forests are poorly understood, due<br />to their sporadic occurrence in natural ecosystems. The findings of this study help<br />to establish the impacts drought may have on these ecosystems and evaluate their<br />potential responses under predicted future climate regimes.</p> / Master of Science (MS)

Dissertation (doctoral)--Lüneburg Universität, 2009.

Thesis (Ph. D.)--Rugers, The State University of New Jersey, 1997. / Includes abstract and vita. Includes bibliographical references (p. 245-257).

Early literature in the field of environmental ethics suggests that environmental problems are not technological problems requiring technological solutions, but rather are problems deeply rooted in Western value systems calling for a reorientation of our values. This dissertation examines what resources are available to us in reorienting our values if this starting point is correct. Three positions can be observed in the environmental ethics literature on this issue: 1. We can go back and reinterpret our Western canonical texts and figures to determine if they can be useful in providing fresh insight on today's environmental challenges; 2. We abandon the traditional approaches, since these are what led to the crisis in the first place, and we seek to establish entirely new approaches and new environmental identities to face the environmental challenges of the 21st century; 3. We look outside of the Western tradition for guidance from other cultures to see how they inhabit and interact with the natural world. This dissertation presents and evaluates these three options and ultimately argues for an approach similar to the third option, suggesting that dialogue with indigenous cultures and traditions can help us to reorient our values and assist in developing more sustainable environmental identities.