<p>The Table Mountain Group (TMG) Aquifer is the second largest aquifer system in South Africa, after dolomites. This aquifer has the potential to be a signinficant source of water for the people of the Western Cape. The occurrence of hot water springs in the TMG in relation with the main geological fault systems in SOuth Africa shows that deep flow systmes do exist. Little is known about these deep aquifer systems in South Africa (i.e. flow mechanisms). To close the above-mentioned knowledge gap, this study was initiated. The current study gave a review of some of the aspects that needs to be considered when distinguishing deep groundwater from shallow groundwater.</p>

<p>Understanding of Groundwater Dependent Ecosystems (GDEs) and their extent within the Table Mountain Group (TMG) aquifer is poor. To understand the dependence to basic ecological and hydrogeological concepts need explanation. The use of current literature aided in identification and classification. From the literature it has come clear that groundwater dependence centers around two issues, water source and water use determination. The use of Geographical Information System (GIS) showed its potential in proof of water sources. Rainfall data and a Digital Elevation Model (DEM) for the Uniondale area have been used to do watershed delineation, which is in line with locating GDEs on a landscape. Thus the conceptual approach should be a broad one that sets a basis for both investigation (scientific research) and institutional arrangements (management).</p>

Benthic algal species receive elevated nitrogen (N) and phosphorus (P) availability as anthropogenic activities increase the loading of nutrients into coastal waters. Pelagic species could also be responding to this nutrient enrichment. This study compared the tissue nutrient content and productivity of three benthic and two pelagic species of Sargassum. We hypothesized that the benthic species would have a higher tissue nutrient content and productivity than the pelagic species and the pelagic species would have a higher tissue nutrient content and productivity than historic data. The tissue nutrient content and net productivity of the benthic and pelagic species were not significantly different indicating that the pelagic species are receiving high levels of nutrient availability comparable to that of the benthic species. Pelagic species in the current study exhibited significantly higher N:P ratios and net productivity than the historic data, suggesting a shift from N to P limitation and increased productivity. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

The focus of my thesis research is on the interplay between individual behavior, population dynamics and community-level processes within zooplankton communities in coastal Maine. The target organisms of my thesis work are marine copepods. Copepods are small (1-10 mm) crustaceans that perform the essential ecosystem function of consuming and assimilating primary production (phytoplankton) making it available to higher trophic levels such as commercially important fishes. Therefore, copepod population growth is of critical importance to marine food webs. Fertilization limitation has been suggested as a constraint on copepod population growth but field surveys describing the prevalence of fertilization limitation are lacking. During my doctoral research, I explored the in situ fertilization success of two marine copepod species, Temora longicornis and Eurytemora herdmani in coastal Maine. I collected monthly zooplankton samples and analyzed clutches from field-caught females using an egg-staining technique. My results indicate that both species exhibit fertilization limitation in nature and the factors correlated with their fertilization span population, community and ecosystem level factors. To determine a causal relationship between predator density and copepod mating success, I conducted laboratory experiments to assess the effects of a common mysid shrimp predator, Neomysis americana on Eurytemora herdmani mating success. I subjected males and females to predators or predator cues. I found that the presence of a mysid predator, or only a predator cue, reduced copulation frequency and spermatophore transfer leading to a 38-61% decrease in E. herdmani nauplii production. These results suggest that mysid predators can constrain copepod population growth through non-consumptive processes. To determine the effects that resources can impose on copepod behavior, I explored the behavioral and fitness consequences of Temora longicornis ingesting Alexandrium fundyense, a phytoplankton species that forms harmful algal blooms in coastal Maine. My results suggest that ingesting A. fundyense causes copepods to swim faster and with more directional persistence compared to control algae. Temora longicornis increased their average swimming velocity by 24%, which leads to a 24-54% increase in their theoretical encounter rate with predators. Therefore, these findings suggest behaviorally mediated copepod-algal interactions may have significant impacts on harmful algal bloom dynamics and the fate of toxins in marine food webs.

No description available.

Forest fragmentation is caused by the clearing of patches of indigenous vegetation for agriculture, urban development, and other human land uses. Such action results in patches of remnant natural vegetation being surrounded by altered vegetation. I investigate the effects of forest fragmentation and matrix type on avian diversity and assemblage structure in forest patches of the historically fragmented Karkloof / Balgowan forest range, KwaZulu-Natal, South Africa. This study compares the bird assemblage diversity and composition of indigenous forest patches surrounded by commercial forestry (Gilboa complex) with that surrounded by natural grassland matrix (Balgowan complex). Insularisation of Afromontane Mistbelt forest in KwaZulu-Natal has led to loss of species where forest fragments support fewer bird species than comparably sized patches of mainland forest. Small fragments within natural grassland have fewer bird species per unit area than larger fragments. Forest patch area-dependent density compensation is evident and bird assemblages appear saturated. Bird assemblages are characterised by a non-random species distribution pattern where area-dependent processes are dominant, and the loss of species from fragments follows a deterministic sequence. In forests in the plantation-dominated matrix no island-effect is detectable and it appears that forest patches are converging on the same bird species richness, regardless of forest size. No density compensation is evident and bird assemblages are not saturated. The sequence of species loss from forest patches is not as predictable, where a random yet prominent colonisation process exists. As commercial plantations provide suitable habitat cover for movement of forest birds, colonisation of both distant and small indigenous forest patches has been possible, reducing the effects of area-dependent extinction in the forest patches but also resulting in lower species richness in larger patches. Bird species of the Karkloof / Balgowan forest range appear to be fragmentation adapted, and most species are resilient to further landscape change. Certain species are however more prone to local extinction than others. The major predictors of extinction risk are body size, abundance status, and feeding guild. Patch area is the dominant force governing traits in the natural Balgowan complex where larger species with low natural abundance and an insectivorous diet are most prone to local extinction. In the Gilboa complex the nature of the plantation matrix appears to be masking the species natural responses to fragmentation making it difficult to predict which species are most at risk. In order to preserve maximum bird diversity, including high-risk species, the largest intact forest units (≥302ha) must be conserved. Evidently, the nature of the matrix affects avifaunal diversity and distribution in forest patches, and plantations have the capacity to significantly alter bird assemblage structure and composition in indigenous forest patches. Forest fragments must be considered as integrated parts of a complex landscape mosaic, and this study emphasises the importance of understanding landscape-scale processes. Knowledge of ecological and life history traits proves valuable for predicting community level response to landscape change. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

At present, compared to our scientific knowledge of how natural biosystems function, we have practically no knowledge of how to engineer biosystems, i.e., how to design, build, repair, maintain, operate, and modify them in a rational and knowledgeable manner. Thus, the EcoCyborg research project was established with the basic intent of making a contribution to the science and engineering of biosystems. / This thesis covers three important arms of study within the overall framework of the EcoCyborg project. The first area is the development and implementation of a workbench for simulation based on composite models. The workbench was designed to accommodate easy integration, synchronization and communication of a number of independent modules. It was developed for use under OS/2 Warp, an operating system that supports multi-process simulation. The functionality of the workbench was tested with a composite model of an EcoCyborg. This composite model contained submodels of an ecosystem, two control systems, and several forcing functions. / The second area is the development and implementation of control systems for biosystems. The control system was intended to guide an ecosystem so that its behavior would best achieve the goals of the controllers which, in this case, were related to the populations of the ecosystem's species. The major part of the work on the control systems was focused on the Pavlovian controller. It mainly covered the investigation of the possibilities to develop and to implement a physiological-level Pavlovian controller. The thesis also presents results from a preliminary investigation on the design and implementation of a cognitive controller. From this, a relatively simple cognitive controller was developed to complement the action of the Pavlovian controller. / The third area is the experimental use of the workbench, and of the Pavlovian and cognitive controllers. For this, ecosystems having various constitutions and their forcing functions were modeled and used in the simulation. Pavlovian controllers with on-off, proportional and proportional plus integral mechanisms were used to control the populations. The cognitive controller was used to maintain minimum population of the various species in the ecosystem. / In general, the workbench that was developed was found suitable to accommodate the simulation of an EcoCyborg composite model. The tools that ware developed for constructing and implementing the Pavlovian controller were tested and found practical and effective for use in constructing Pavlovian controllers of various configurations. The results of the work on the cognitive controller provided useful information for its further development.

Fire has been an important influence on the structure and health of the North American grasslands for hundreds of years. In Jersey County Illinois, two natural loess hill prairies were studied to compare the effectiveness of varying management regimes. The purpose was to determine how a burn vs. a nonburn management regime enhances or hinders the establishment of the prairie grasses and forbs in a tallgrass hill prairie ecosystem. The variables studied included: the vegetational abundance, the frequency, and the biomass of the species that were present. In addition the soil's organic matter content and pH were measured. Overall, the Fire Road Prairie, or the unburned prairie, proved to be the community that was deteriorating and becoming unproductive. Whereas, the Osage Prairie contained a balance of grasses and forbs that were representative of a healthy and thriving community. The data supported the existing theory that a burn management plan does help the overall stability and productivity of a tallgrass ecosystem. / Department of Natural Resources and Environmental Management

<p>Understanding of Groundwater Dependent Ecosystems (GDEs) and their extent within the Table Mountain Group (TMG) aquifer is poor. To understand the dependence to basic ecological and hydrogeological concepts need explanation. The use of current literature aided in identification and classification. From the literature it has come clear that groundwater dependence centers around two issues, water source and water use determination. The use of Geographical Information System (GIS) showed its potential in proof of water sources. Rainfall data and a Digital Elevation Model (DEM) for the Uniondale area have been used to do watershed delineation, which is in line with locating GDEs on a landscape. Thus the conceptual approach should be a broad one that sets a basis for both investigation (scientific research) and institutional arrangements (management).</p>

<p>The Table Mountain Group (TMG) Aquifer is the second largest aquifer system in South Africa, after dolomites. This aquifer has the potential to be a signinficant source of water for the people of the Western Cape. The occurrence of hot water springs in the TMG in relation with the main geological fault systems in SOuth Africa shows that deep flow systmes do exist. Little is known about these deep aquifer systems in South Africa (i.e. flow mechanisms). To close the above-mentioned knowledge gap, this study was initiated. The current study gave a review of some of the aspects that needs to be considered when distinguishing deep groundwater from shallow groundwater.</p>