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Remote sensing offers major contributions to the understanding of northern landscapes and vegetation patterns. Recently available instrumentation and analytic techniques, yielding new types of data and new approaches to longstanding problems, are demonstrated in this analysis of terrain conditions and vegetation distributions in the Caribou Hills, N.W.T. The analysis of landform was based on field data, image interpretation and photogrammetric elevation model data. Slope angles and aspects were computed and trend surfaces, residuals and contour maps produced for model areas. Within sampled areas, surface roughness, the degree of dissection and the apparent dominance of either fluvial or mass wasting processes were found to be controlled by slope aspect, snow drifting patterns and the nival melt schedule. Patterns of active layer depth and details of surface materials, morphology and processes were derived from stereoscopic analysis of photographs through linkages with plant associations. Twelve plant associations, defined by field survey, provided a basis for differentiating photographic signatures and vegetation mapping classes. The character and separability of the spectral signatures were reviewed using ratioed and clustered optical film density data. The major advantages of remote sensing as an analytic tool were demonstrated. Remote sensing provides a vast array of geographic data and a unique synthesis of terrain and vegetation conditions offering the researcher key information that is otherwise unavailable.

As part of a vegetation survey program for the newly acquired farms incorporated into the Loskop Dam Nature Reserve, the vegetation of the Hondekraal Section was investigated. The study provides an ecological basis for establishing an efficient wildlife management plan for the Reserve. From a TWINSPAN classification, refined by Braun-Blanquet procedures, 12 plant communities, which can be grouped into eight major plant communities, were identified. A classification and description of the major plant communities are presented as well as a management plan. Descriptions of the plant communities include characteristic species as well as prominent and less conspicuous species of the tree, shrub, herb and grass strata. This study proves that the extended land incorporated into the Reserve contributes to the biological diversity of the Reserve. / Environmental Sciences / M. Tech. (Nature Conservation)

The natural vegetation of the Cradle of Humankind World Heritage Site (COH WHS) was classified using Braun-blanquet methodology. This identified 22 distinct plant communities and 2 variants. Sampling took place over two growing seasons with a total of 91 releves being compiled. A stratified random approach to sampling used Land Types as a means of primary area stratification, with terrain position providing the means for further refinement. The grassland comprised of 12 plant communities and 2 variants and the woodland comprised of 10 plant communities. The classification of the woodland areas included some bush clumps associated with the entrances of caves which were also described independently in which seven distinct plant communities were identified A positive linear correlation exists between the size of the cave entrances and the extent to which the surrounding woody vegetation extends. This suggests the likelihood of cave entrance size influencing the surrounding vegetation. / Environmental Sciences / M. Tech. (Nature Conservation)

Desertification is the diminution or destruction of the biological potential of land, and can lead ultimately to desert-like conditions. The vegetation of southern Africa is claimed to have altered over the past 100 years and much of the change is attributed to pastoral practice. In recent years however there has been much debate around the issue of the deterioration and loss of productivity of the natural rangelands, specifically those under communal management. It is one thing to claim that the vegetation has changed but quite another to produce data and analyses to show this unequivocally. Furthermore it is generally difficult to determine the nature and extent of change in natural ecosystems, as one does not know what the optimal base-line conditions should be. For this reason emphasis has been placed on developing models of potential or expected vegetation. By comparing a model of potential or expected vegetation with that of the contemporary vegetation, areas that deviate from expectation can be identified, in so doing providing evidence of the direction of change in the rangelands under various management treatments. The objective of this study was to determine shifts in the vegetation under different land-use treatments, by developing a technique to predict the potential vegetation of an area. In order to explore the nature and extent of degradation at the landscape scale a study site was selected where a range of land-use and rangeland management practices could be studied in parallel. The mid-Fish River valley consists of three markedly different units of land management, namely commercial rangelands, communal rangelands and nature conservation areas. The vegetation within the mid-Fish River valley falls within the Thicket biome and consists of three main vegetation types namely, Short Succulent Thicket, Medium Succulent Thicket and Mesic Bushclump Savanna. The creation of this potential vegetation model was dependent on the direct gradient analysis approach of relating the community patterns with environmental variables. To achieve this, floristic information was collected at sites along a topographical-moisture gradient. A Canonical Correspondence Analysis (CCA) between the environmental variables and the plant communities produced a classification from which the conditions normally associated with the major plant communities were predicted. When projected as a digital map, the qualifying sites provided a testable hypothesis of the potential vegetation. The results of this study showed a definite grazing gradient, which reflects a change from a more mesic environment towards a more arid environment with an increase in utilisation pressure. The predictive vegetation model proved to be useful for predicting the occurrence of the valley thicket communities within the Eastern Cape.

A vegetation survey, on the plant community level of organization, was conducted on the Mfabeni swamp on the eastern shores of Lake St Lucia. The survey included both the sedge/grass swamp and the swamp forest. Mfabeni swamp is a peatland with peat up to 10m in depth. Except for limited studies in Lesotho and KwaZulu-Natal, this is a first vegetation survey on the plant community level of peatland vegetation in southern Africa. Total floristic composition and habitat information were recorded in 214 sample plots, fully referenced by GPS for GIS mapping. The data were captured in the TURBOVEG data base for vegetation data, classified using the TWINSPAN numerical classification algorithm and phytosociological tables were compiled using the MEGATAB computerized table management program. Fourteen plant communities were identified, characterized by diagnostic and dominant species, described, and the localities noted by GIS. The data were also processed by the PCOrd numerical ordination program and the axes of the resulting ordination diagrams were related to environmental conditions. This gave an indication of the environmental factors controlling the existence and distribution patterns of the different plant communities. An ordination was run on the habitat data collected to further illustrate the relationship between the plant communities and environmental variables. It seems that water depth, seasonality of the water depth and certain water chemical properties, such as pH conductivity and dissolved oxygen content of the water play an important role in determining floristic composition and therefore plant community type in the Mfabeni swamp. / Dissertation (MSc(Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

Includes bibliographical references (p. 301-319). Palaeoecological records, documented historical records and remnant vegetation were investigated in order to construct a multi-scaled history of vegetation pattern and change in the Fleurieu Peninsula, South Australia over the last c. 8000 years. Aims to better understand post-European landscape transformation and address the inherently historical components of the problems of regional biodiversity loss, land sustainability and the cumulative contribution to global climatic change.

Includes bibliographical references (p. 301-319). / xx, 319, [30] leaves : ill. (some col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Palaeoecological records, documented historical records and remnant vegetation were investigated in order to construct a multi-scaled history of vegetation pattern and change in the Fleurieu Peninsula, South Australia over the last c. 8000 years. Aims to better understand post-European landscape transformation and address the inherently historical components of the problems of regional biodiversity loss, land sustainability and the cumulative contribution to global climatic change. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geographical and Environmental Studies, 2001

The Ngorongoro Crater is a volcanic caldera located within the Ngorongoro Conservation Area in Tanzania. The Crater comprises a flat grassland plain surrounded by steep, bushy walls. It contains extremely high densities of animals and is ecologically the central feature of Ngorongoro Conservation Area. The management of the Ngorongoro Crater has changed significantly in recent times, with cattle being removed and fire excluded about 30 years ago. A detailed vegetation assessment was carried out in the Crater floor by Herlocker & Dirschl in 1972. Since then noticeable changes in vegetation structure and composition, with associated changes in wild herbivore numbers have occurred. The original vegetation survey was repeated in this study as accurately as possible using similar point-based techniques in order to quartify changes and form a baseline for management decision-making and future monitoring. In addition to repeating the vegetation survey, the standing biomass was estimated using a Pasture Disc Meter with associated calibration equations. Data were summarised using multivariate classification and ordination techniques in order to delineate six Homogenous Vegetation Units (HVUs) which can be used for management and management planning purposes, define transects and HVUs in terms of dominant species, describe the main species in relation to their occurrence in different associations and determine the fuel load of the standing crop. A key grass species technique was developed for rapid assessment of the Crater rangeland by the Ngorongoro Conservation Area staff who only need to be familiar with the dominant species. Bush surveys using a point centred quarter technique were conducted along transects in two distinct vegetation types, namely the Lerai Forest and Ngoitokitok Acacia xanthophloea forests and the lower caldera scrub vegetation. The data collected from these transacts were analysed to determine density and composition of the vegetation in the various height classes and the overall structure of the vegetation communities, A range monitoring system in conjunction with a controlled burning programme has been developed to provide an objective means of managing the- rangeland of the Ngorongoro Crater. Data revealed that changes have taken place in the vegetation, with a trend towards dominance by taller grasses and dominance by fewer species. Lack of fire has probably contributed to these changes. Reincorporating fire in the crater is recommended. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

Pine plantations have been established on secondary grassland on the dune systems of the Eastern Shores of Lake St Lucia, KwaZulu-Natal, South Africa for the past 40 years. These plantations have been progressively felled for the past six years, and will continue to be felled until the year 2011, by which time they will be eliminated. Space-for-time substitution was used to determine the direction of both woody and herbaceous vegetation succession and to predict possible future management implications for the Eastern Shores. Soil samples were taken from undisturbed grassland, grassland with trees, dune forest, pine plantations, and clearfelled areas at various successional stages. To determine the effects of the pine plantations on the soils of the area, soils were subjected to particle size analysis, and determination of pH, organic carbon, phosphorus, exchangeable bases, iron and aluminium. Minimal modification of the sandy soils by the pine plantations was found to have occurred. That which did occur was shown to be short-term, and to be ameliorated by the establishment of an indigenous woody understorey, resembling pioneer dune forest. Soil under plantations was shown to have a lower pH and cation exchange capacity than under opposite indigenous vegetation but no other direct effects were observed. The direction of succession was determined by the nature of the indigenous vegetation adjacent to the plantation. Pine plantations were shown to facilitate succession towards dune forest by the exclusion of fire, provision of perches and refugia for forest-dwelling animals, and creation of a forest environment for the establishment of trees. However, the extent of re-establishment of indigenous dune forest under pine plantations was shown to be directly related to the nature of the adjacent indigenous vegetation, be it grassland, grassland with trees or dune forest. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.