The analyses of trends in vegetation dynamics require a profound knowledge of its seasonality. For the determination of the seasonality conventional methods of time series analyses often use a simple averaging of measured values of the identical time in different cycle of the whole time series (e.g. bfast). Then it is assumed that the resulting seasonal portion of a time series is constant and stable for the entire time series. However, analyses of vegetation time series show that trends in vegetation dynamics do not always run steadily, but show structural breaks, especially in regions with high potential for possible landscape changes. For such conversion areas, the assumption of a constant seasonality is not always ensured. The dynamic or variability of the seasonality can have temporal effects by a shift of the start of the season (SOS) or the end of the season (EOS) and therefore also on the length of the vegetation period. To show whether seasonal dynamics can be detected in vegetation time series, two requirements must be fulfilled. (1) High-temporal resolution vegetation information provided for example as MODIS-NDVI. (2) Indicators are needed which allows the description of the variability of seasonality. As a result these metrics allow a better modeling of long-term vegetation dynamics in the trend, taking into account the variability of the seasonality. But at the same time the metrics itself serve as indicators for long term vegetation dynamics. The aim of the present study is to analyse phenological and greenness metrics for the modelling of vegetation dynamics in the nature reserve Königsbrücker Heide. Detailed analyses of key metrics like SOS and EOS using different metric approaches and interpolation methods are applied and compared. The results show that it is dificult to determine consistent information for example for the trend of single phenology metrics.

MEVNSC / Department of Geography and Geo-Information Sciences / Vegetation is one of the most important renewable natural resources to play a role in the preservation of the environment and biodiversity. Various land use activities such as urbanization, population growth and other anthropogenic activities, as well as climate change have been some of the major drivers which alter vegetation cover and contribute to biodiversity loss. This research study uses remote sensing and Geographical Information System to quantify vegetation and land cover change in Makhado over a five-year period (2007 - 2012). This study used multi-temporal satellite image data to identify the dynamic pattern of vegetation change and the negative impacts it has on the environment. The research uses remote sensing techniques and GIS software to analyse data. In addition, satellite imageries were used to study the spatial and temporal distribution of vegetation. The results of the study show that settlement areas have been on a stable positive and mostly uncontrolled expansion from 17.73% of the study area in 2007 to 30.52% in 2012. Vegetation on the other hand, has been on a steady decline, from 10.65% in 2007 to 5.92% in 2012, as well as the ecosystems quality on which biodiversity depends for their existence and to a greater extent the climate conditions, with an increase in temperature, methane, nitrous oxide and carbon dioxide. The monitoring of vegetation change can play a vital role in knowledge generation, best practices and as well as Environmental Monitoring and Evaluation which can be abated in the near future. This study recommends that the South Africa Government and public agencies concerned develop policies and strategies to bring about balanced, coordinated and sustainable development in the municipality and its district.

Orientador: Veridiana de Lara Weiser Bramante / Resumo: O Cerrado é considerado um dos 25 hotspots mundiais, uma das áreas prioritárias para a conservação da biodiversidade mundial, por apresentar uma alta biodiversidade, um alto grau de endemismo e suas espécies estarem ameaçadas de extinção. Sendo assim, é fundamental o desenvolvimento de estudos na vegetação de cerrado para subsidiar trabalhos de conservação, manejo e restauração ecológica. O presente estudo visou conhecer as espécies que constituem o estrato de regeneração natural de uma área de cerradão na Gleba II do Refúgio de Vida Florestal Aimorés, em Bauru, centro-oeste do estado de São Paulo, sudeste do Brasil. Por meio do método de parcelas, realizamos o inventário da regeneração natural em duas classes de altura. A classe I (H ≤ 50 cm), chamamos de banco de plântulas e amostramos em subparcelas de 2 m x 2 m e a classe II (50 cm < H ≤ 1 m) chamamos de jovens regenerantes, amostramos em subparcelas de 5 m x 5 m. Alocamos as duas subparcelas no canto inferior esquerdo de 25 parcelas permanentes de 10 m x 10 m. Para cada classe de altura da regeneração natural analisamos os parâmetros de riqueza e abundância, calculamos o índice de diversidade de Shannon (H’) e equabilidade (J), os índices de regeneração natural por classe (RNC) e total (RNT).Utilizamos o índice de Sorensen para avaliar a similaridade florística entre as classes de altura da regeneração natural e entre a regeneração natural como um todo e o estrato arbóreo amostrado em dois períodos, 2005 e 2019. Amostram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cerrado is considered one of the 25 hotspots, one of the priority areas for the conservation of global biodiversity, as it presents a high biodiversity, a high degree of endemism and its species are threatened with extinction. Therefore, it is essential to develop studies in the cerrado vegetation to support conservation, management and ecological restoration work. The present study aimed to know the species that constitute the natural regeneration stratum of woodland cerrado area in the Wildlife Refuge Aimorés, in Bauru, middle west of the state of São Paulo, southeastern Brazil. Using the plot method, we carried out the inventory of natural regeneration in two height classes. Class I (H ≤ 50 cm), we call the seedling bank and sample in subplots of 2 m x 2 m and class II (50 cm <H ≤ 1 m), young regenerators, we sample in sub plots of 5 m x 5 m. We allocated the two subplots in the lower left corner of 25 permanent plots of 10 m x 10 m. For each height class of natural regeneration, we analyzed the parameters of species richness and abundance, calculating the Shannon diversity index (H') and equability (J), the natural regeneration indices by class (RNC) and total (RNT). We used the Sorensen index to assess the floristic similarity between the height classes of natural regeneration and between natural regeneration and the tree strata sampled in two periods, 2005 and 2019. We sampled 617 individuals from the seedling bank, belonging to 44 species and 680 young regenerating... (Complete abstract click electronic access below) / Mestre

Since European American settlement of the Intermountain Region, dramatic changes in vegetation composition and structure have occurred in the sagebrush steppe ecosystem. Western juniper (Juniperus occidentalis spp. occidentalis Vasek), although indigenous to the Intermountain Region, has increased since the late 1800s. Considerable work has been done documenting juniper woodland expansion in the Intermountain West, however, little is known about the environmental variables that influence rates of tree establishment and structural attributes of woodlands across landscapes. Most studies of western juniper have addressed site-specific questions at limited spatial scales. Consequently, there is a lack of research on broader scale patterns of woodland development occurring across heterogeneous landscapes. In addition, changes in the amount, composition, and structure of fuels during the transition from open sagebrush steppe communities to closed juniper woodlands have profound influences on the size, intensity, frequency, and behavior of fire. However, limited data exist quantifying changes in fuels during this transition, thus, consequences to fire behavior have been difficult to predict. The major impetus for the study was to determine the influence of environmental variables on rates and structural attributes of woodland development and associated changes in fuel loading characteristics during the transition from sagebrush steppe communities to closed juniper woodlands in the High Desert and Humboldt ecological provinces. The proportion of trees greater than 150 years old relative to trees less than 150 years suggest western juniper has greatly expanded in the Owyhee Mountains and on Steens Mountain since settlement of the areas. Ninety-five percent of the trees established after the 1850s. As evidenced by the presence of western juniper in 96% of plots sampled in this study, juniper is able to encroach upon a variety of plant alliances and under a broad range of environmental conditions over diverse landscapes. Although it appears the occurrence of western juniper within the woodland belt is not spatially limited by environmental or vegetative conditions, stand structural and fuel loading characteristics do vary considerably across heterogeneous landscapes. Total juniper density, density of dominant trees comprising the primary canopy, and certain live and dead fuels biomass very substantially with site potential. Spatial variation in stand structure and fuels may have significant implications to management of juniper at the landscape scale. / Graduation date: 2005

Multispectral video (MSV) images were used to measure phenological changes in cultivated and uncultivated vegetation communities surrounding the Palo Verde Nuclear Generating Station (PVNGS). Multispectral video imagery was acquired from aircraft on seven dates between the middle of June and the end of September, 1986. Images representing three sites near the PVNGS were selected to calculate Ratio Vegetation Index (RVI) values for seven surface cover types. Mean RVI values were tested sequentially for change, plotted as a function of time, and then compared to a moisture index and the crop calendar. MSV detected changes in cultivated vegetation corresponding to the crop calendar. Changes in natural vegetation and the non-vegetated cover types were also detected, but did not correlate to the moisture index. There is insufficient evidence to determine if detected changes in uncultivated vegetation were the result of phenological changes or electronic noise.

Balancing increasing elephant numbers with biodiversity conservation in small reserves has become a concern for many protected area managers. Elephants are considered important agents of disturbance creating heterogeneity and thus contributing to the maintenance of biodiversity. However elephants also damage vegetation through their destructive feeding habits, and this has led to pressure to reduce elephant populations in many reserves. Quantitative data on the impact of elephants on invertebrates, the main component of biodiversity at the species level, are lacking. The aim of this project was to assess the effect that habitat alteration by elephants has on the diversity of selected ground-dwelling invertebrates (ants, centipedes, millipedes, spiders, scorpions and termites) through the provision of logs and dung as a potential refuge niche for these invertebrate communities, and to determine the effect of spatial (vegetation types) and temporal (season and age of dung) variation on the invertebrates using these refugia. Variation in impacts was considered important because savanna is not homogenous and the impact of the refugia is likely to be dynamic in terms of seasonal trends in invertebrate populations, and in terms of changes in the environmental conditions offered by the refugia. Elephant impact on vegetation, quantity of refugia (logs and dung) produced and invertebrate diversity associated with refugia were determined for 115 transects within Madikwe Game Reserve in the North Western Province, South Africa. Invertebrate abundance, species richness and diversity were always higher under refugia than in areas without refugia. Vegetation utilisation, frequency of refugia production and invertebrate diversity showed strong temporal variation (seasonal); elephant impact and production of logs were higher in winter than in summer because elephants are more likely to feed on woody vegetation in winter when grass nutrient levels are low. Invertebrate diversity under the logs was higher in summer than in winter, and this probably reflected the higher abundance and diversity of invertebrates that are usually associated with the warmer, wetter summer months. The effect of adding refugia to three vegetation types on invertebrate diversity was tested experimentally at Makalali Private Game Reserve in the Limpopo Province, South Africa. Logs and elephant dung were set out in five plots each measuring 20m x 20m within Govender - iii mixed bushveld, riverine and mopane woodland. Significant differences were observed in invertebrate abundance, species richness and diversity between the refugia and control plots that lacked refugia and between the three vegetation types sampled. Similarity between invertebrate communities utilising the different refugia types and between the three different vegetation types were tested using the Jaccard similarity coefficient. The three vegetation types shared fewer than 50% of their species, as did the logs, dung and control sites. However the results obtained do illustrate a higher degree of similarity between the refugia substrates (logs and dung) than the control sites and between the more heterogeneous vegetation types (mixed bushveld and riverine) than the mopane veld. This indicated that invertebrate communities associated with refugia were not uniform, but were influenced by vegetation type. An experimental test of temporal changes in invertebrate community composition illustrated the importance of elephant dung as a microhabitat for different invertebrate groups over different ages of dung (three days, two, four, 12 and 32 weeks old). Colonisation of the dung, by dung beetles was immediate but as the microclimate of the dung changed with time, the new conditions were ideal for other invertebrate taxa. Over a period of eight months, the change of invertebrate communities utilising the dung included dung beetles, followed by millipedes and [mally ant and termite communities. The results of this study illustrated the importance of refugia (logs and dung) produced by elephants for ground-dwelling invertebrate species in the savanna environment. The extent of the influence of the refugia varied both spatially and temporally and this should be considered in future monitoring or in measuring impacts. While further research on a broader range of organisms and at larger scales is necessary, elephants do have a positive impact on at least some components of biodiversity, through the process of facilitation of refugia. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

A dissertation Submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science. . / The cyclone Domoina floods of 1984 were responsible for the large scale destruction and devastation of riverine vegetation in the Umfolozi Game Reserve. This event highlighted the need to gain an understanding af the structure and dynamics of riverine vegetation and to use this knowledge to develop a management strategy directed at the future recovery and maintenance of riverine vegetation in the Umfolozi Game Reserve. (Abbreviation abstract) / Andrew Chakane 2018

Research into seed biology and restoration ecology of areas disturbed by mining is crucial to their revegetation. Shark Bay Salt, a solar salt facility in the Shark Bay World Heritage Area in Western Australia has several areas of disturbance as a result of 'soil borrowing'. Soil from these areas termed 'borrow pits' was used to create infrastructure such as the roads and embankments surrounding the evaporation ponds. Many of the pits contain little to no vegetation after >10 years since disturbance ceased, hence research into their restoration is now essential. A vegetation survey at the site established the key species in the undisturbed vegetation, and investigated the vegetation in borrow pits subject to natural migration and topsoil replacement. The vegetation communities in the borrow pits were vastly different to those in the undisturbed vegetation, highlighting the need for research into revegetation. An investigation into the use of 'borrowed' topsoil on a small scale showed that seedling recruitment from 'borrowed' topsoil was generally similar in the donor site (natural vegetation) and the borrow pits. Due to the absence of topsoil for further revegetation, it was necessary to understand seed germination and dormancy characteristics to establish seed pre-treatments prior to seed broadcasting and seedling (greenstock) planting. An investigation into seed germination and dormancy characteristics of 18 common species revealed that most species germinated equally well at 26/13oC and 33/18oC, however seven species had improved performance at 26/13oC. Untreated seeds of seven species exhibited high germination. Seeds of two species had low imbibition, which increased with hot-water treatment, and hence require scarification for germination. Germination of seeds of three species substantially increased with gibberellic acid (GA3), smoke water (SW) and karrikinolide (KAR1, a butenolide isolated from smoke). Seeds of the remaining six species had low germination regardless of treatment. As a result, species were classified as likely to be non-dormant (44%), physiologically dormant (44%) or physically dormant (11%). Physiological dormancy of three species was at least partly alleviated by dry afterripening, whereby moisture content of seeds was adjusted to 13% or 50% equilibrium relative humidity and seeds were stored at 30oC or 45oC for several months. All iv after-ripening conditions increased germination percentage and rate of two species with one only germinating when treated with GA3 or KAR1. The germination of the third species was dependent on after-ripening temperature and seed moisture content.

This thesis examined vegetation change over the last 43 years in Australia's largest contiguous alpine area, the Kosciuszko alpine zone in south-eastern Australia. Using historical and current data about the state of the most common vegetation community, tall alpine herbfield, this thesis addressed the questions: (1) what were the patterns of change at the species/genera and life form levels during this time period; (2) what were the patterns of recovery, if recovery occurred, from anthropogenic disturbances such as livestock grazing or trampling by tourists; (3) what impacts did natural disturbances such as drought have on the vegetation and how does it compare to anthropogenic disturbances; and (4) What are the benefits, limitations and management considerations when using long-term data for assessing vegetation changes at the species/genera, life form and community levels? The Kosciuszko alpine zone has important economic, cultural and ecological values. It is of great scientific and biological importance, maintaining an assemblage of vegetation communities found nowhere else in the world. It is one of the few alpine regions in the world with deep loamy soils, and contains endemic flora and fauna and some of the few periglacial and glacial features in Australia. The area also forms the core of the Australian mainland's most important water catchment and is a popular tourist destination, offering a range of recreational opportunities. The vegetation of the Kosciuszko alpine zone is recovering from impacts of livestock grazing and is increasingly exposed to pressures from tourism and anthropogenic climate change. At the same time, natural disturbances such as drought and fire can influence the distribution, composition and diversity of plants. Thus, there is a need for detailed environmental data on this area in order to: (1) better understand ecological relationships; (2) understand existing and potential effects of recreational and management pressures on the region; (3) provide data against which future changes can be assessed; and (4) provide better information on many features of this area, including vegetation, for interpretation, education and management. The research in this thesis utilised three types of ecological information: (1) scientific long-term datasets; (2) photographic records; and (3) a comparison of disturbed and undisturbed vegetation. This research analysed data from one of the longest ongoing monitoring programs in the Australian Alps established by Alec Costin and Dane Wimbush in 1959. Permanent plots (6 transects and 30 photoquadrats) were established at two locations that differed in the time since grazing and have been repeatedly surveyed. Plots near Mt Kosciuszko had not been grazed for 15 years and had nearly complete vegetation cover in 1959, while plots near Mt Gungartan showed extensive impacts of grazing and associated activities which only ceased in 1958. Some transect data from 1959 to 1978 have been analysed by the original researchers. The research presented in this thesis extends this monitoring program with data from additional surveys in 1990, 1999 and 2002 and applies current methods of statistical evaluation, such as ordination techniques, to the whole data set for the first time. Results indicated that the recovery from livestock grazing and the effects of drought have been the main factors affecting vegetation. Recovery from livestock grazing at the three transects at Gungartan was slow and involved: (1) increasing genera diversity; (2) increasing vegetation cover; (3) decreasing amounts of bare ground; and (4) a directional change over time in species composition. Patterns of colonisation and species succession were also documented. In 2002, 44 years after the cessation of grazing, transects near Mt Gungartan had similar vegetation cover and genera diversity to the transects near Mt Kosciuszko, but cover by exposed rock remained higher. A drought in the 1960s resulted in a temporary increase of litter and a shift in the proportional cover of life forms, as grasses died and herb cover increased at both locations. Proportions of cover for life forms reverted to pre-drought levels within a few years. The results also highlighted the spatial variability of tall alpine herbfield. The photoquadrats were surveyed in the years 1959, 1964, 1968, 1978 and 2001 and are analysed for the first time in this thesis. After comparing a range of methods, visual assessment using a 130 point grid was found to be the most suitable technique to measure vegetation cover and genera diversity. At the 18 quadrats near Mt Gungartan, there was a pattern of increasing vegetation cover as bare areas were colonised by native cudweeds and the naturalized herb Acetosella vulgaris. Revegetation from within bare areas largely occurred by herb species, while graminoids and shrub species predominately colonised bare ground by lateral expansion from the edges, eventually replacing the colonising herbs. At the 12 quadrats near Mt Kosciuszko, vegetation cover was almost complete in all years surveyed except 1968, which was at the end of a six year drought. Similar to the results from the transect study, the drought caused an increase in litter at both locations as graminoid cover declined. Initially herb cover increased, potentially as a result of decreased competition from the graminoids and a nutrient spike from decaying litter, but as the drought became more severe, herb cover also declined. Graminoid cover rapidly recovered after the drought, reaching pre-drought levels by 1978, and was at similar levels in 2001. Herb cover continued to decline after peaking in 1964. The photoquadrat study also documented the longevity and growth rates of several species indicating that many taxa may persist for several decades. It further provided insights into replacement patterns amongst life forms. In addition to assessing vegetation change following livestock grazing and drought at the long-term plots, recovery from tourism impacts was examined by comparing vegetation and soils on a closed walking track, with that of adjacent undisturbed tall alpine herbfield at a series of 22 paired quadrats. Fifteen years after the track was closed there was limited success in restoration. Over a quarter of the closed track was still bare ground with non-native species the dominant vegetation. Plant species composition differed and vegetation height, soil nutrients and soil moisture were lower on the track which had a higher compaction level than adjacent natural vegetation. The results presented in this thesis highlight that tall alpine herbfield is characterised by nearly entire vegetation cover which is dominated by graminoids, followed by herbs and shrubs in the absence of disturbance by livestock grazing, trampling or drought. The studies also showed that under quot;average" conditions, the relative cover of herbs and graminoids remained fairly stable even though there can be considerable cycling between them. Spatial variability in terms of taxa composition was high. The only common introduced species in unrehabilitated sites was Acetosella vulgaris, which was effective at colonising bare ground but was eventually replaced by other native species. However, in areas actively rehabilitated, such as on the closed track, non-native species introduced during revegetation efforts still persist with high cover 15 years after their introduction. Monitoring of vegetation change is also important at the landscape scale. This thesis provides a review of the potential use, the limitations and the benefits of aerial photography to examine vegetation change in the Kosciuszko alpine zone. Numerous aerial photography runs have been flown over the area since the 1930s for government agencies, industry and the military. Some of these records have been used to map vegetation communities and eroding areas at a point in time. Other studies compared different types and scales of photographs, highlighting in particular the benefits and potential of large scale colour aerial photography to map alpine vegetation. However, despite their potential to assess vegetation change over time, a temporal comparison of vegetation in the Kosciuszko alpine zone from aerial photographs has not been completed to this date. Historical photographs may not be easy to locate or access and difficulties with vegetation classification may restrict the practicality of using historical aerial photographs to assess vegetation change. Despite these issues, aerial photography may provide a very useful and efficient tool to assess changes over time when applied appropriately, even in alpine environments. The development of digital classification techniques, the application of statistical measures of error to both methodology and data, and the application of geographic information systems are likely to further improve the practicality of historical aerial photographs for the detection of vegetation change and assist in overcoming some of the limitations. The results presented in this thesis highlight the need for limiting disturbance, for ongoing rehabilitation of disturbed areas and for long-term monitoring in the Kosciuszko alpine zone. The results contribute to our understanding of how vegetation may change in the future and may be affected by new land use activities and climate change. This type of information, which otherwise would require the establishment of long-term studies and years of monitoring, can assist land managers of this and other important protected areas. The study highlights how the use and expansion of already existing datasets to gather ecological information can save considerable money and time, providing valuable data for current and emerging issues.

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