The vegetation of the sand dunes on Long Beach, Vancouver Island, was studied on 116 sample plots. The purpose of this study was to describe the floristic and edaphic characteristics of the plant associations, to determine the major environmental factors controlling the distribution of the plant communities and to study the successional trends of the vegetation. The vegetation was described using the analytical and synthetical methods of the Zurich-Montpellier school of phyto-sociology. This thesis describes seven plant associations and four variants. The vegetation units are as follow: A. Foreshore habitats 1. Cakiletum edentulae B. Blowout habitats 2. Poetum macranthae a. poosum macranthae , b. abroniosum latifoliae 3. Arctostaphyleto-Rhacomitrietum canescentis C. Habitats of the mobile dune ridge 4. Elymetum vancouverensis a. ammophilosum arenariae b. elymosum vancouverensis D. Habitats of the dune slack and stable dune ridge 5. Aireto-Ceratodontetum purpurei 6. Arctostaphyleto-Eurhynchietum oregani 7. Hetergenous communities i n moist dune slack habitats E. The dune forest habitat 8. Piceeto-Gaultherieto-Maianthemetum dilatati Important environmental factors which control the distribution of these associations are the level of winter and storm tides, wind, the amount of sand burial and blowout that occurs in the habitat and the amount of available soil water. The first stages of succession begins in the unstable habitats of the Elymetum vancouverensis and Poetum macranthae. With stabilization of the habitat, these associations are succeeded by the Aireto-Ceratodontetum purpurei and the Arctostaphyletum-Eurhynchietum oregani in exposed habitats and the Arctostaphyleto-Rhacomitrietum canescentis in habitats well protected from wind. All vegetation eventually reaches the climax Piceeto-Gaultherieto-Maianthemetum dilatati. / Science, Faculty of / Botany, Department of / Graduate

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1981. / Microfiche copy available in Archives and Science / Vita. / Bibliography: leaves 170-178. / by Kevin Michael Bohacs. / Sc.D.

Call number: LD2668 .T4 1965 A67 / Master of Science

Inland sand dunes supporting Grey Hair-grass Corynephorus canescens are a declining European habitat designated for conservation under the EU’s Habitats Directive. In Britain they are confined to a handful of sites in East Anglia and the West Midlands. This study investigated the relationships of the British populations to each other and to populations on five sites in Poland, where C. canescens is still widespread. It also conducted exploratory investigations into factors relevant to the conservation of this ecosystem, particularly in the West Midlands. Data were collected chiefly from 1m2 quadrat samples and direct sampling, which recorded the plants and animals present together with parameters such as vigour and fecundity in C. canescens, amounts of bare sand and litter, and measures of erosion and grazing. These data were variously analysed including by CANOCO multivariate analysis and, for the vegetation, TWINSPAN analysis. 153 taxa of plants and 251 of invertebrates were identified. Though strongly distributed on a regional basis, both flora and invertebrate fauna showed relationships particularly between Polish and West Midlands sites. Analysis of the vegetation suggested that West Midlands vegetation had some associations with C. canescens habitats in Europe and that East Anglian vegetation had links with British coastal C. canescens habitats. The invertebrate fauna showed some complex community relationships in Poland and the West Midlands but less so in East Anglia, while assemblages of invertebrates were associated with various vegetational and abiotic factors. Rabbits and hares were the only vertebrates regularly exploiting C. canescens habitats, which they grazed and, in the former case, produced sand disturbances for colonisation by C. canescens. Ants and to a lesser degree some other invertebrates also produced sand disturbances. Observations made in a preliminary cultivation study in the West Midlands suggested that C. canescens may have a biennial phenology, high fecundity, low germination rates and limited dispersal powers in that region. A trampling investigation suggested that C. canescens may be very sensitive to heavy uncontrolled trampling and to vegetational succession under protection. Stages in succession of the C. canescens community were identified, and suggestions for further study and the conservation of C. canescens were drawn up.

Sand dune erosion is highly episodic occurring only when storm waves coincide with high tides generating swash that impacts the toe of the dune. Owing to the episodic nature of sand dune erosion, it is difficult to observe in nature. The removal of a structure and rip-rap sea-wall from the Stilwell Hall site located in southern Monterey Bay provided a unique opportunity to study erosion processes at an accelerated rate. A 1-D wave impact line erosion model (Larson et al., 2004) was tested against data acquired at this site between April, 2004 and April 2005. The model was optimally tuned to the data by a dimensionless coefficient that relates the impact force to the rate of recession. The coefficient values ranged from 0.7-1.3x10-3, for this field data, compared with values of 1.0-2.5x10-3 previously obtained for lab and field data. Migrating rip currents create a system of mega-cusps, which are nominally 10m in width and 200m in alongshore wavelength (Thornton, 2005). The presence of megacusps is hypothesized to accelerate sand dune erosion at their embayments where the beach is steeper and narrowest (Short, 1979;Shih and Komar, 1984;Revell, et al., 2002). It was determined that the highest recession occurred at the location of the rip current/mega-cusp embayment. Changes in the surf climate are of great interest to Naval Special Warfare (NSW) and U.S. Marine Corps (USMC) forces tasked with planning and executing operations in littoral areas. Naval history is replete with operations highlighting the importance of understanding and accurate prediction of nearshore dynamics. Without the ability to predict nearshore morphologic processes, providing such support is impossible.

Sand movement is one of the many environmental problems facing humans in the dry and semi-dry areas of the world. This study has investigated the observed changes in sand dune coverage compared to predictions, and has also assessed the impact of sand movement on human activity in the north western coastal region of Libya. The study used three methods. The first was a statistical model proposed by Bagnold, which correlates wind shear velocity with particle size, in order to predict likely sand movement. It was found that 60% of sand grains within the study area have a diameter of less than 0.25 mm, making them liable to be moved by the wind speeds recorded, particularly from March until September, and mostly in a northerly direction. The sand in the western part of the study area had a greater predicted rate of sand transport compared with the sand in the eastern part, which was related to its origin. The second method involved the analysis of satellite images for four different years; from 1986 to 2003. The land cover in the study area was found to have changed over this time. Sand dune area cover had increased, and there were other changes particularly a decline in forest. The third method was the use of a questionnaire (the respondents being land owners), which showed that there was notable loss of crop production (by about a quarter) due to sand movement, and that land owners mostly used afforestation to help control the sand movement in the region. The observed sand movement did not match the predictions based solely on sand grain size and wind speed, and climatic analyses showed no convincing trends which could explain increased sand movement except perhaps an increase in wind gusts. The thesis concludes that the overriding determinant in greater sand movement over the period studied was the loss of forest from the area due to human impacts, which farmers are having to compensate for by planting trees locally to reduce sand movement.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the Degree of Master of Science. Johannesburg, 20 January 2017. / Sand dune movements can be effectively monitored through the comparison of multitemporal satellite images. However, not all remote sensing platforms are suitable to study sand dunes. This study compares coarse (Landsat 7 and 8) and fine (Worldview 2) resolution platforms, specifically focussing on sand dunes within the Ubārī Sand Sea (Libya), and identified the average migration rate and direction for the linear dunes within a section of the Ubārī sand sea for the time period from 2002-2015 with the use of Landsat imagery. Two band combinations were compared with the use of two supervised classifications. The best combination was found to be red, green, blue and near-infrared band combination and the maximum likelihood classifier. The dune features, namely the crest, slope and interdunal areas were successfully classified based on both the coarse and fine resolution imagery, but the accuracy with which it can be classified are different between the two resolutions. The classifications based on the Worldview 2 imagery had overall accuracies ranging from 55.43 - 60.83% with kappa values of 0.3486 – 0.4225 compared to the overall accuracies and kappa values of the classifications based on the Landsat 8 imagery ranging from 52.11 – 64.67% and 0.3878 – 0.4927 respectively. An average migration rate of 8.64 (± 4.65) m/yr in a generally north western direction was calculated based on the analysis of remote sensing data with some variations in this rate and the size and shape of the dunes. It was found that although Worldview 2 imagery provides more accurate and precise mensuration data, and smaller dunes identified from Worldview data were not delineated clearly on the Landsat imagery. Landsat imagery is sufficient for the studying of dunes at a regional scale. This means that for studies concerned with the dune patterns and movements within sand seas, Landsat is sufficient. In studies where the specific dynamics of specific dunes are to be selected, a finer resolution is required; platforms such as Worldview are needed in order to gain more detailed insight and to link the past and present day climate and environmental change. / MT2017

No description available.

Outer Cape Cod (Massachusetts) is dominated by active and stabilizing parabolic and transverse dunes interspersed with numerous inter-dune wetlands. Dune migration has been significantly affected by human activities; conversely, current dune movements are affecting local populations. The objective of the reported research was to assess, using remote sensing and geographic information systems (GIS) technologies, migration of the Cape Cod dunes and the effect of dune movement on distribution of associated wetlands. Aerial photographs from 1938 through 2003 were analyzed to track individual dune movements and subsequent wetland propagation and expansion. Absolute dune movement rates during this period were computed, with a plot of dune movement as a cumulative function. One sub-problem of this study was to quantify `white' areas of active moving sand and `dark' areas of vegetation, in order to quantify changes in vegetative cover with wetland propagation and, conversely, vegetative disappearance with dune movement. Attempts were made to correlate the Palmer Drought Severity Index (PDSI) with dune migration. Based on review of aerial photographs, parabolic dunes have migrated 150 to 250 m since 1938, with 60% of the movement occurring between 1938 and 1977. The relation between absolute parabolic dune migration and corresponding PDSI is approximately logarithmic. Maximum dune migration is associated with PDSI values lower than -2 and reflects moderate drought conditions. Wetlands consistently trailed the dunes, and the distance of wetland movement was related to dune movement distances. Wetland migration was particularly marked from the 1950s to the 1980s. Based on review of georeferenced aerial photographs, it is concluded that marked stabilization of Cape Cod dunes occurred in the 1980s and 1990s, with renewed movement in the 21st Century. This study provides a practical application for assessment of dune migration and vegetative transformations over time using remote sensing and GIS technologies. / Department of Natural Resources and Environmental Management

This study focuses on the ecological restoration of a coastal dune ecosystem on the east coast of Vancouver Island that supports bird migration. The area is also a part of the traditional homelands of the Tsawout First Nation. Because environmental degradation has impaired the functioning of both ecological and cultural systems, the restoration of this ecosystem requires a distinctive approach. An “ethnoecological” approach to restoration is presented that seeks collaboration between ecological science and traditional ecological knowledge in order to restore the ecological integrity and human connection to this culturally significant landscape. Guided by the values of the Tsawout community, and the practice of good ecological restoration, I make recommendations for short and long term restoration actions. A set of ethnoecological restoration guidelines are presented to help guide future projects with the dual mandate of ecology and culture. Finally, opportunities for making connections between this project and other regional initiatives are explored in an attempt to restore links in the migratory habitat chain.