Made available in DSpace on 2015-04-09T12:28:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-01Bitstream added on 2015-04-09T12:48:23Z : No. of bitstreams: 1 000814063.pdf: 1739194 bytes, checksum: 5c8305af26fb9bea8982272f23f1a178 (MD5) / A detecção de grandes carnívoros, como as onças - pardas ( Puma concolor) , é dificultada por apresentar em baixa densidade de indivíduos, além dos hábitos elusivos e de difícil observação. A técnica de amostragem através de métodos não invasivos, como as fezes, podem permitir acessar várias informações incluindo a identificação do animal, área de vida e comp osição da dieta , entre outras , usando técnicas moleculares. A possibilidade de utilizar as fezes como medida indireta para estudos de populações em projetos de gerenciamento e conservação de vida selvagem depende do sucesso da coleta das amostras orgânicas . Frente a isso, foi analisado o esforço amostral para a coleta das fezes de onça - parda com intuito de otimizar o tempo e custos no planejamento das ações em campo. F oram analisadas variáveis de cunho antrópico e abi ótico da área de estudo: distâ ncias en tre os locais de coleta de amostras com as lagoas, sedes e estradas; a pluviosi dade média do período de coleta; os intervalos de dias da última precipitação ; o intervalo entre as visitas e intervalos desde a última amostra encontrada. Em todas as trilhas percorridas houve a presença d e pegadas de onças - pardas, poré m em apenas algumas delas foram encontradas fezes. Dessa forma a marcação territorial desses animais pode estar relacionada aos fatores autoecológicos da própria onça - parda através das marcações químicas e físicas, além de fatores antrópicos e abióticos indicando preferência por locais próximos à s lagoas e mais isolados de grande movimentação humana. Foi possível , também , estimar um intervalo de dias que otimize as visitas a campo, com a média do número de dias do intervalo entre as visitas indicando entre 7 – 9 dias como um intervalo ótimo para visita s ao campo, com fins de encontrar fezes de onças - pardas e com a última amostra encontrada por volta de 20 dias antes. / TThe detection of large carnivores such as the Puma ( Puma concolor ) , is hindered by the fact that they show low density, elusive habits and are hard to be seen. Sampling procedures via noninvasive methods, like using feces, can allow the access to a number of information regarding the behavioral ecology of the species, including the identity of each i ndividual – using DNA extraction - home range and diet . The use of feces as an indirect population measurement in wildlife management and conservation depends on the successful collection of them . Faced with this, we analyzed th e sampling effort to collect Pumas’ feces in order to optimize time and cost in planning field actions . A nthropic and abiotic variables of the study area were analyzed: dista nces between sampling sites to ponds, farmhouse and roads; the average rainfall in the gathering period; time p eriod from the last rainfall; the period between visits and time interval from the last sample found. In all pathways there were trails of footprints from pumas , but feces were found only in specific spots. Thus, territorial marking by these animals, using chemical and physical patterns, may be due to ecological causes from the species itself , and anthropogenic and abiotic factors . This study indicat ed puma preference for locations close to ponds and those more isolated from human activity . It was also pos sible to estimate a range of days that optimizes the field visits, with the average number of days in the period between visits being 7 - 9 days as the optimal interval for field visits in the aim of finding puma feces. And it was establish ed that is most pr obable to find a sample when the last one has been found around 20 days before.

Orientador: Carlos Camargo Alberts / Banca: Sérgio Nascimento Stampar / Banca: Gelson Genaro / Resumo: A detecção de grandes carnívoros, como as onças - pardas ( Puma concolor) , é dificultada por apresentar em baixa densidade de indivíduos, além dos hábitos elusivos e de difícil observação. A técnica de amostragem através de métodos não invasivos, como as fezes, podem permitir acessar várias informações incluindo a identificação do animal, área de vida e comp osição da dieta , entre outras , usando técnicas moleculares. A possibilidade de utilizar as fezes como medida indireta para estudos de populações em projetos de gerenciamento e conservação de vida selvagem depende do sucesso da coleta das amostras orgânicas . Frente a isso, foi analisado o esforço amostral para a coleta das fezes de onça - parda com intuito de otimizar o tempo e custos no planejamento das ações em campo. F oram analisadas variáveis de cunho antrópico e abi ótico da área de estudo: distâ ncias en tre os locais de coleta de amostras com as lagoas, sedes e estradas; a pluviosi dade média do período de coleta; os intervalos de dias da última precipitação ; o intervalo entre as visitas e intervalos desde a última amostra encontrada. Em todas as trilhas percorridas houve a presença d e pegadas de onças - pardas, poré m em apenas algumas delas foram encontradas fezes. Dessa forma a marcação territorial desses animais pode estar relacionada aos fatores autoecológicos da própria onça - parda através das marcações químicas e físicas, além de fatores antrópicos e abióticos indicando preferência por locais próximos à s lagoas e mais isolados de grande movimentação humana. Foi possível , também , estimar um intervalo de dias que otimize as visitas a campo, com a média do número de dias do intervalo entre as visitas indicando entre 7 - 9 dias como um intervalo ótimo para visita s ao campo, com fins de encontrar fezes de onças - pardas e com a última amostra encontrada por volta de 20 dias antes. / Abstract: TThe detection of large carnivores such as the Puma ( Puma concolor ) , is hindered by the fact that they show low density, elusive habits and are hard to be seen. Sampling procedures via noninvasive methods, like using feces, can allow the access to a number of information regarding the behavioral ecology of the species, including the identity of each i ndividual - using DNA extraction - home range and diet . The use of feces as an indirect population measurement in wildlife management and conservation depends on the successful collection of them . Faced with this, we analyzed th e sampling effort to collect Pumas' feces in order to optimize time and cost in planning field actions . A nthropic and abiotic variables of the study area were analyzed: dista nces between sampling sites to ponds, farmhouse and roads; the average rainfall in the gathering period; time p eriod from the last rainfall; the period between visits and time interval from the last sample found. In all pathways there were trails of footprints from pumas , but feces were found only in specific spots. Thus, territorial marking by these animals, using chemical and physical patterns, may be due to ecological causes from the species itself , and anthropogenic and abiotic factors . This study indicat ed puma preference for locations close to ponds and those more isolated from human activity . It was also pos sible to estimate a range of days that optimizes the field visits, with the average number of days in the period between visits being 7 - 9 days as the optimal interval for field visits in the aim of finding puma feces. And it was establish ed that is most pr obable to find a sample when the last one has been found around 20 days before. / Mestre

Doctor of Philosophy / Division of Biology / Martha E. Mather / Understanding the complex relationship between organismal distribution and spatial heterogeneity is central to many ecological questions. This challenge of identifying the biodiversity consequences of spatial patterns is especially critical for resource conservation at the larger riverscape scale because climate- and human-related impacts often act through intricate and spatially-connected organismal-habitat relationships. Specifically, resource managers cannot manage the adverse effects of common disturbances on aquatic ecosystems (e.g. water-withdrawal, dams, urbanization) if the influence of spatial heterogeneity is not recognized and understood. Towards this larger goal, I examined the role of spatial heterogeneity on stream fish biodiversity in the Upper Neosho River, KS in three ways. First, I used a mosaic approach (in which connected, interacting collections of juxtaposed habitat patches were examined) to build the scientific foundation for a general model that aids in the understanding and environmental management of disturbance-related, ecologically-based conservation problems. Second, I examined landscape metrics to quantify the impact of low-head dams on stream habitat and fish diversity. Third, I evaluated multiple quantitative approaches to develop a fuller understanding of how the arrangement of habitats across the riverscape influenced stream fish biodiversity. Related to these questions, the dissertation research provided four key take-home messages that advanced science-based conservation related to stream fish habitat and biodiversity. First, mapping larger-scale patterns of heterogeneity showed that quantitatively-different, physically-distinct pool, riffle, run, and glide habitats were arranged in unique combinations created diverse habitat mosaics across sites. Second, riffles, which comprised < 5% of all habitat patches, acted as keystone habitats that disproportionately increased fish biodiversity (i.e., species richness was significantly higher in mosaics with higher numbers of riffles). Third, mosaic approach metrics provided new insights into the influence of low-head dams on stream fish biodiversity that were not detected with traditional approaches to habitat sampling and statistical analysis. For example, low-head dams dampened the natural habitat diversity that is needed for the maintenance of resilient communities. Furthermore, using path analysis, I found that species richness was higher immediately below low-head dams as mediated through an increase in the proportion of riffle habitat, but this higher species richness was offset by a greater decrease in species richness in the impoundment habitat above low-head dams. Thus, the choice of scale influenced the interpretation of how dams affected habitat heterogeneity and resultant organismal patterns. Finally, landscape approaches to examining compositional and configurational heterogeneity provided new insights about stream fish habitat-biodiversity relationships. For example, riffle patch density had a positive effect on species richness, species richness was higher within shallow, slow flowing riffles, and adjacent neighbor habitats affected riffle species richness as mediated through alterations to within-habitat characteristics. In summary, quantifying the complex patterns of spatial heterogeneity in a range of ways can aid in the understanding of habitat-biodiversity patterns and help conserve stream fishes at a variety of scales.

The number of people on our planet is projected to rise to between 9.4 and 10 billion by 2050. Some estimates suggest that current levels of food production will need to double to feed this population. Increasing the intensity of food production on existing agricultural land will be a crucial element in meeting this goal, but practices associated with intensive management can cause biodiversity declines and erode the ecosystem functions that underpin production. My work explores agricultural intensification within the context of pasture-based cattle production. I focus on a variety of ecosystem functions supported by dung beetles (Coleoptera: Scarabaeoidea) and other dung-associated invertebrates. I investigate how variations in diversity, and chemical perturbations of veterinary anthelmintics affect the delivery of multiple ecosystem functions. I show that maintaining species-rich dung beetle assemblages has inconsistent benefits in providing multiple ecosystem functions. While dung beetles play an important role in supporting functioning in the short term, my work also reveals that their contributions may be less evident when considered over longer periods. Chemical perturbations caused by anthelmintic residues represent a significant threat to some invertebrate groups, but my experiments show that exposure does not always translate into an immediate reduction in ecosystem functioning. While use of anthelmintic products with relatively low toxicological risk did not cause obvious reductions in function, my work shows exposure can have significant consequences for the conservation of sensitive species. Overall, my work highlights the need for multigenerational studies, mathematical modelling, and careful consideration of sublethal effects to assess fully the risks of anthelmintic residues in the pasture environment. Furthermore, the emphasis on dung beetles (rather than other dung-associated invertebrates) in the existing literature neglects potentially important functional benefits provided by other taxa, such as earthworms. As the global human population continues to expand, it is important that we find sustainable ways to produce food while simultaneously conserving biodiversity. As loss of biodiversity in agricultural ecosystems does not always have functional consequences, it is important that wider justifications for conservation remain integrated into agricultural policy and practice.

This thesis investigates the influence of nonrandom species loss on the structure and functioning of trophic floodplain lagoons. Two experiments were conducted based on different realistic scenarios of biodiversity loss using multitrophic fish assemblages derived from long-term survey data. Loss of fish diversity influenced overall ecosystem multifunctionality of these lagoons through complex multitrophic interactions throughout the aquatic food web. These results indicate that biodiversity loss from diverse multitrophic ecosystems can influence ecosystem structure and function and likely deviate from simplified food chain dynamics or patterns that emerged from single trophic level studies.

Abiotic and top down control hypotheses do not adequately explain the fine scale distribution patterns of shrub and tree Colophospermum mopane (Caesalpinioideae). Genetic distinctiveness between growth forms is investigated as an alternative hypothesis. Tree and shrub C. mopane from the riparian and inland savanna zones were sampled at four sites in the northern Kruger National Park. Molecular DNA sequences were obtained for four plastid and one nuclear region, and the inter simple sequence repeat (ISSR) technique used to fingerprint individuals. Very low levels of sequence divergence were observed. The ISSR technique revealed no genetic structure between plants when grouped by growth form or by habitat in an analysis of molecular variance (AMOV A). Soil profile and xylem pressure potential data also did not explain the distribution of growth forms. A principle component analysis and a discriminant analysis of five leaf and branching characters identified a significant difference in the shape of shrub and tree C. mopane leaves. It is concluded that the C. mopane growth forms are not genetically distinct and that their fine scale distributions may be due to top down controls such as large mammals and fire.

The effectiveness of the structural defences of Acacias vary within and between species as a result of differences in thorn type (hooks versus spines) and branching architecture. This study aims to develop methods for quantifying the effectiveness of defences, thereby allowing for comparisons between individuals and localities. Measurements of a range of thorn and branching parameters of eight Acacia species were used to calculate three indices (stripping, biting and branching) describing different components of Acacia structural defences. These were combined to form an overall defence index that was tested against the results of three feeding simulation tests as well as actual animal feeding rates obtained from trials using nyala held in bomas. The stripping, biting and branching indices were shown to provide a good measure of the different components of a structural defence, although the scaling of their contribution to an overall defence index is complicated by variation in the suite of browsers and the resources available at a locality. The indices developed in this study provide a useful tool for assessing the role of large mammal herbivory in different environments when attempting to understand variation in the life history strategies of Acacias.

A one-year experimental fishery for P. delagoae was established in April 2004 to determine the frequency and magnitude at which pulse fishing may be sustainable (Government Gazette 2004). Determining the extent of recovery after fishing is one aim of the experimental fishery. Assessments of the growth rate, size at sex maturity and natural mortality of P. delagoae were performed in 2000 (Groeneveld et al) and can be supplemented by the results of this study, which assess the reproductive biology of the East Coast spiny lobster in order to address this aim. A recent study (Groeneveld in press) assessed fecundity, egg loss during gestation, relative reproductive potential and lifetime egg production per recruit for P. gilchristii from three areas along the South African south coast. A general east-west trend of increasing fecundity, size at sexual maturity, and lifetime egg production per recruit was found for P. gilchristii. Examining egg-loss through the first four ( of six) developmental stages of gestation showed significant loss of around 15 % by stage four, irrespective of lobster size (Groeneveld in press). The study of fecundity in P. gilchristii ( Groeneveld in press) was used as a framework for assessing the fecundity of P. delagoae in this study.

Zandvlei is a system that has been highly modified by the urban environment of Cape Town. Salinity is a major driver determining the physical environment of estuaries. The macroalgal community of estuaries forms an important part of the ecology of these systems as primary producers. The salinity of this environment is an important parameter determining the composition, abundance and diversity of these communities. Patterns of salinity fluctuations in the long term (1978-2003) and annually are described in order to establish how communities may vary. Zandvlei is in a Mediterranean climate and salinity was found to vary seasonally and monthly with fluctuations in rainfall. Historical records of macroalgae identified in the estuary were summarized and no record of the Polysiphonia sp., now dominant in the estuary, was found. Dominant macroalgae in the estuary were identified and grown under a range of salinities (0, 1, 5, 10, 20, 29 ppt). Dominant macroalgae included Cladophora sp., Polysiphonia sp. and Enteromorpha prolifera. None of these algae survived at O ppt. In 1 ppt E. prolifera survived but growth was retarded, Polysiphonia sp. survived but did not grow and Cladophora sp. grew successfully at this salinity. All three species have different optimum ranges for growth with E. prolifera preferring higher salinities, Cladophora sp. grew similarly across the range from 1 to 29 ppt and Polysiphonia sp. grew most rapidly at 5 ppt. Depending on the salinity range in the estuary different macroalgae will be dominant. This makes the macroalgae community quite resilient to fluctuating salinities. There should therefore always be estuarine macroalgae present in the estuary provided salinity does not drop below 1 ppt for an extended period. If salinities did drop below 1 ppt there could be an increase in freshwater algae.

The biophysical drivers of fire; ignition, fire weather conditions, fuel biomass, and flammability, differ in varying ecosystems. The rates of occurrence of these factors influence fire regimes. This study investigated the causes and consequences of a severe wildfire that swept through the Hluhluwe Game Reserve, KwaZulu-Natal South Africa in September 2008. This fire was an extreme event that seems only to have been possible due to the combination of circumstances that occurred in the days prior to and during the 14th/15th September 2008. The event was considered extreme because it burnt from savanna into thicket and forest patches, which is atypical of fires. The fire caused large structural change in tree demography, however, not much change in densities. The results of this study indicate that coupled weather conditions conducive to fire; namely low relative humidity, high temperatures and high wind speeds, occurred at the time of the fire. The synergistic influences of fire weather conditions and the state of available fuel caused this severe fire. The fire continued to bum for 48 hours before weather conditions relaxed and became less dangerous. These data suggest extreme fires such as the September 2008 event may be exploited by managers to reclaim former grasslands and savannas that have suffered the effects of bush encroachment and/or create open areas allowing grasslands to develop. However, severe fires run the risk of leading to the loss of forests and the biodiversity that they support. This study has identified the conditions likely to promote such severe fires.