• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 98
  • 23
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 139
  • 139
  • 28
  • 24
  • 18
  • 16
  • 15
  • 14
  • 14
  • 13
  • 13
  • 10
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

An evaluation of the Riparian Vegetation Index (RVI) in KwaZulu-Natal.

Clarke, Simon. January 2003 (has links)
No abstract available. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
52

Assessing riparian habitat : an approach for planning rehabilitation.

Challen, Duncan Nicholas Rance. January 2001 (has links)
Riparian systems perform many critical ecological functions and services. Riparian areas are in urgent need of rehabilitation to restore their natural functioning. In order to successfully implement rehabilitation efforts in riparian areas, a management plan for rehabilitation is required. An important facet of a management plan would be the assessment of riparian habitat quality. The aim of this study is to produce a riparian habitat assessment approach that would be helpful in developing a rehabilitation management plan. The approach needs to assess habitat from a landscape scale through to a site scale, be concise, user friendly, effective and be able to be used by all land managers. It must also allow for the identification of areas of high asset value that will be prioritised for rehabilitation efforts. Existing local and international habitat assessment methodologies reviewed did not satisfactorily meet all the above objectives. Accordingly, a new methodology for riparian habitat assessment was developed, consisting of a 3-leve1 approach which assesses habitat from a landscape scale (macroscale assessment), a reach scale (intermediate-scale assessment) and at a site scale (microscale assessment). The approach was tested in a case study of the Rivers Bend farm in the Nkwaleni Valley, KwaZulu-Natal, South Africa. The developed methodology allows for an assessment technique of riparian areas that now explicitly includes landscape attributes, local characteristics of the river system (reach scale) and site scale level of assessment. Both the macroscale and the microscale assessments produced spatial representations of asset values within the study area. These areas were prioritised for rehabilitation efforts. Although these assessments produced results for identifying asset sites, the scoring· systems did not reflect the changes in habitat quality with enough detail. It is recommended that the characteristics determining the quality ratings and the scoring systems of these assessments be reassessed. The intermediate-scale assessment produced relevant stream profiles and gradient classes, but the application of the assessment did not successful1y delineate the river into homogenous segments. Further study is required to better integrate the 3-levels of the developed methodology. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2001.
53

River and wetland conservation and preservation issues in Arizona : a study of agenda building

Wilkosz, Mary Elizabeth. January 1989 (has links)
Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1989. / Includes bibliographical references (leaves 183-193).
54

A comparative study of small mammal communities in riparian and upland mixed-conifer forest habitats /

Mamone, Mario Salvatore. January 1994 (has links) (PDF)
Thesis (M.S.)--Southern Oregon State College, 1994. / Typescript. Includes bibliographical references (leaves 73-80). Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.
55

The land-water interface : patterns of riparian vegetation and channel morphology in the Oregon Coast Range system /

Takahashi, Mayumi. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references (leaves 70-73). Also available on the World Wide Web.
56

Riparian vegetation and larval Pacific Giant (Dicamptodon tenebrosus) and adult Western Redback (Plethodon vehiculum) salamanders in the Oregon Coast Range /

Graff, Paula January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.
57

River and riparian dynamics and black cottonwoods in the Kootenay River Basin, British Columbia and Montana

Polzin, Mary Louise, University of Lethbridge. Faculty of Arts and Science January 1998 (has links)
The black cottonwood, Populus trichocarpa, provides the foundtaion for the riparian woodlands throughout southern British Columbia (B.C.) and western Montana (MT). To study the interaction of riparian dynamics and cottonwood ecology, the present study investigated the influence of the extreme 1995 Elk River flood on the riparian zone and cottonwood ecology, and the effects of flood flow attenuation by the Libby Dam on riparian processess and cottonwoodland ecology of the Kootenai(y) River. Four river reaches were studied: the free-flowing Elk River near Fernie, B.C., the free-flowing Upper Kootenay River, B.C., upstream from the Koocanusa Reservoir, the free-flowing Fisher River, MT, near the Kootenai junction, and the flow-attenuated Lower Kootenai River near Libby, MT. Air photos from 1930, 1962, 1992 and/or 1994 revealed substantial channel change and the development of barren point bars that served as recruitment sites for willos and cottonwoods along the free-flowing reaches. Conversely, the Lower Kootenai had a relatively static channel after damming. In total, thirty-five transects were studied in 1996 and 1997 at 3 sites along each river reach to assess elevation profiles, substrate composition, scour and deposition, vegatation patterns, and aspects of cottonwood reproduction. Abundant cottonwood recruitment occurred in 1996 and even more so in 1997, producing mean densities of 153, 536, and 142 seedlings/m2 along the Elk, Upper Kootenay, and Fisher river transects, respectively. In marked contrast, no seedlings were successful along the Lower Kootenai River, downstream from the Libby Dam. The free-flowing river reaches experienced extensive sediment deposition in the riparian zone after the 1997 high water, whereas the Lower Kootenai experienced little change in stream bank configuration. The Elk River study revealed that the 1995 flood caused considerate geomorphic change and the resultant unconsolidated deposits were easily scoured and transported during the subsequent two years providing abundant sites for new cottonwoods. The Kootenay River study revealed limited meandering and deposition along the flow-attenuated Lower Kootenai River compared to the hydrologically, geomorphologically, and ecologically dynamic, free-flowing upstream reach. Along the Lower Kootenai River, there was a deficiency in black cottonwood population age structure due to limited recruitment. Flood-intolerant, upland plants have encroached to the river's edge, further eliminating cottonwood recruitment opportunities along the Lower Kootenai River. The vegetation encroachment, the static channel configuration, the minimal scour and sediment deposition and the lack of the essential stream stage pattern, combine to underlie the lack of seedling recruitment and the consequent deficiency in cottonwood population structure along the Lower Kootenai River. The studies demonstrate that black cottonwoods require a dynamic hydrologic and geomorphic system with periodic flood events for continued replenishment. The observed loss of cottonwood recruitment along the Lower Kootenai River is thus the consequence of the flood flow attenuation due to the operation of the Libby Dam. The restoration of the Lower Kootenai cottonwoods will probably rely on a partial recovery of more natural and more dynamic instream flow patterns that include occasional high flows in late spring followed by gradual stage recession. Such flows would exclude upland vegetation, recover more dynamic geomorphic processes and provide the stream stage patterns that are directly essential for cottonwood seedling recruitment. / 1 v. (various pagings) : ill. (some col.), maps ; 28 cm.
58

Conditions that define a riparian zone in southeastern Arizona

Jemison, Roy Leonard,1952- January 1989 (has links)
Riparian areas in Arizona have been centers for man's activities such as farming, cattle grazing, recreation, wildlife habitat, water, and cities, since the early 1800's. Representing less than one percent of Arizona's land resource base, riparian areas have received a disproportionately high amount of use and abuse. Public and private awareness of the necessity to preserve and manage riparian areas was aroused in the late 1960's by the Arizona Fish and Game Department and United States Forest Service with a study documenting that clearing of riparian areas was detrimental to wildlife habitats. Since the early 1970's national conferences, studies, and legislation concerning protection, preservation, and management of riparian areas have demonstrated the increasing public interest for riparian areas. Proper management of riparian areas requires land managers to have information on the environmental parameters active in these areas. Riparian areas have been studied since the 1930's, but early studies looked mainly at how to increase water yields from riparian areas through vegetation management. It has only been since the 1970's that studies have been aimed at protection and preservation of riparian areas. This dissertation documents an added effort to broaden the existing knowledge on riparian areas in the southwest. A riparian area bordering Paige Creek in southeastern Arizona was monitored for 24 months. Environmental data (e.g. precipitation, streamflow, watertable levels, soils, soil water status, and vegetation) were collected and analyzed with the objective, to determine if soil moisture content could be used as an indicator of a riparian area in the absence of typical riparian vegetation. Statistical tests indicated soil moisture in the upper 48 inches of soil could not be used to indicate the riparian area. The position of existing riparian vegetation was controlled by the location of the watertable. Unless the location of the free water supply is known, soil moisture readings alone could prove misleading.
59

Site design for xeroriparian wildlife habitats in urbanizing areas of Eastern Pima County, Arizona

Burns, Jennifer M. January 1988 (has links)
This thesis integrates wildlife management and biology, urban residential development, and the hydrology of desert watercourses. Literature is surveyed within each area and information is applied to the issue of wildlife conservation in urbanizing areas of Eastern Pima County. It is recognized that some natural wildlife habitats and wildlife species are valued by urban residents. Valuable areas of wildlife habitat are being lose due to conventional residential development strategies. This paper discusses the impact of typical residential development on native Southwestern wildlife species and habitat. Alternative development design guidelines are proposed which would provide viable wildlife habitat within developed areas. Design guidelines which are presented in this paper are applicable to low elevation arid areas in the Southwest where developers are seeking to integrate natural wildlife habitat within residential areas.
60

Pre-harvest water quality of ephemeral streams in Missouri Ozark forests

Smith, Abraham J. January 2006 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2006. / 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 (February 23, 2006) Includes bibliographical references.

Page generated in 0.0621 seconds