Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 73-74). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 2005. / 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 (November 14, 2006) Vita. Includes bibliographical references.

No description available.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 153-168).

Thesis (Ph. D.)--Washington State University, May 2009. / Title from PDF title page (viewed on Apr. 20, 2010). "School of Biological Sciences." Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references (leaves 108-112). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 135-152). Also available on the World Wide Web.

Water is one of our key and indispensable natural resources. It plays a fundamental part in life (and the quality thereof), the environment, food production, hygiene, industry and power generation. Water is one of the major limiting factors in South Africa when it comes to economical growth and social development. In our country water is a scarce resource which is unevenly distributed both geographically and through time. As the demand for water increases, with increasing human populations and economic development, so to does the pollution of our river ecosystems.The Elands River is one of these natural resources that is under constant threat. It falls within the Incomati Water Management Area and is further sub divided into the Crocodile River sub area. This sub area is highly stressed, as it provides water for several human activities. The Elands River is a major tributary of the Crocodile River. The Crocodile River is a source of fresh water for several towns and is used by industry, rural and the agricultural communities (including tobacco farms). The Elands River in turn, is used for irrigation of vegetables. Both these rivers support a rich diversity of aquatic life. Along with its social and economical importance, the Elands River has immense ecological importance, as it holds great biodiversity including critically endangered biota. The main anthropogenic impacts on the Elands and Crocodile rivers include: · The Sappi Ngodwana Mill and the associated pulp and paper activities · The influence of the Ngodwana dam wall on the flow and water quality within the lower Ngodwana River · Nutrient loading taking place due to the treated sewage that is released into the river in the upper reaches and in the vicinity of the Mill · Sedimentation and flow regulation that is taking place in the Crocodile River, upstream of the confluence with the Elands River · And the agricultural activities within the Elands River system. The activities related to the Mill are the major concern in the study. The Sappi Ngodwana Mill is situated at the confluence of the Elands and Ngodwana rivers. The mill does not discharge effluent directly into the river. The effluent is however, irrigated onto the 514 hectares of farmlands adjacent to the Mill. The irrigated effluent has contaminated the groundwater in this area and the primary influence of this groundwater contamination is the deterioration of the surface water quality as well as, negatively impacts the quantity of water in the Elands River. The groundwater enters the Elands River through three springs near Ngodwana namely Fraser’s eye, Northern eye and Eye X. The groundwater from both Fraser’s eye and Eye X has been contaminated with calcium, potassium, magnesium, sulphates and most importantly chlorides. All these substances contribute to the increase in conductivity in the Elands River, which in turn may have a possible impact on the ecological integrity of the system. The pulp and paper industry is a large consumer of water and few regrettable incidents over the years have given the industry a reputation as a major water polluter. The industry’s management of water is,however, of world class and every attempted is made to manage the environment in a sustainable manner. This study aims to assess the impact of these anthropogenic activities on the associated aquatic ecosystems. Assessing the impact of anthropogenic activities on the aquatic environments, like the Elands River, has in the past been based mainly on the assessment of water quality. Earlier management of water resources has thus been based on the potability of water. Over the last decade management initiatives have expanded to include domestic, agricultural, recreational and most importantly instream (fish, invertebrates etc.) users. It has become common practise to use aquatic biota to assess the impacts of human activities of freshwater resources. The reason for this is that animals and plants can provide a long–term integrated reflection of water quality, quantity, habitat quality and other environmental conditions. Water and sediment quality was assessed by applying standard techniques and protocols. Additionally historical water quality data was obtained from the Sappi Ngodwana Mill and the Department of Water Affairs and Forestry. Habitat quality was assessed by implementation of habitat quality indices. This included that Integrated Habitat Assessment Index and the Habitat Quality Index. The vegetation at each site was identified in the field with the assistance provided by the members of the Elands River Valley Conservancy and using various field guides and the riparian zone was then demarked. The integrity of the fish community was assessed by implementing the Fish Assemblage Integrity Index and the Fish Response Assessment Index. The integrity of the aquatic macro invertebrate communities was also assessed. This was achieved through use of the South African Scoring System and the Macro Invertebrate Response Assessment Index. Finally, spatial and/or temporal trends were assessed by implementation of various multi variate statistical procedures. / Prof. J.H.J. Van Vuren Prof. V. Wepene

Thesis (M.S.)--University of Puerto Rico, Mayagüez Campus, 2004. / Tables. Printout. Abstract in English and Spanish. Includes bibliographical references (leaves 30-38).

This study was conducted in the Afram Headwaters, Tain Tributaries Block II and Worobong South Forest Reserves. Satellite record of fire incidence for the country over 11 years (1997 to 2007) was modelled via binary logistic regression analysis, and correlations between fire incidence and the correlates of fire used to explain the observed trends. Fire incidence was found to be correlated with multiple variables which probably covary. Rainfall, vegetation type and geology showed the strongest correlations with fire incidence. Recurrent fire has impacted negatively on forest structure, ground cover biomass and species composition in two forest reserves, but more marked in the wetter Worobong South Forest Reserve than the drier Tain II Forest Reserve. Basal area has reduced from 40 m²ha^-1 in least-degraded to <1 m²ha^-1 in heavily-degraded stand in Worobong South Forest Reserve, along with tree density, whereas canopy openness has increased from 6% in least-degraded to 83% in heavily-degraded forest. In Tain II Forest Reserve, however, the heavily-degraded forest has lost close to 50% of its maximum value in terms of basal area, tree density and canopy cover, all in approximately 20 years. Early-burning, with maximum seedling height growth rates of 130 cm yr^-1 and 40 cm yr^-1 for Worobong South and Tain II Forest Reserves respectively, might help control the fires, and restore forest canopy in about 10 to 20 years if regularly maintained, but must be accompanied by green firebreaks. Complete protection from fire (during convalescence), on the other hand, would take between five and 15 years to restore forest canopy, but at huge resource cost. Implications for sustainable forest management are discussed.