Dissertations / Theses: 'Habitat modelling'

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MacDonald, Jane Shaw. "Modelling a Population in a Moving Habitat." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36701.

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The earth’s climate is increasing in temperature and as a result many species’ habitat ranges are shifting. The shift in habitat ranges threatens the local persistence of many species. Mathematical models that capture this phenomena of range shift do so by considering a bounded domain that has a time dependant location on the real line. The analysis on persistence conditions has been considered in both continuous-time and -space, and discrete-time, continuous-space settings. In both model types density was considered to be continuous across the boundaries. However it has been shown that many species exhibit particular behaviour at habitat edges, such as biased movement towards the more suitable habitat. This behaviour should be incorporated into the analysis to obtain more accurate persistence conditions. In this thesis persistence conditions are obtained for generalized boundary conditions with a continuous-time and -space model for a range-shifting habitat. It is shown that a high preference for the suitable habitat at the trailing edge can greatly reduce the size of suitable habitat required for species persistence. As well, for fast shifting ranges, a high preference at the trailing edge is crucial for persistence.

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Van, Ael Susan M. "Modelling barred owl habitat in northwestern Ontario." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/MQ33461.pdf.

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Johansson, Maya. "Modelling habitat suitability index for golden eagle." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-197086.

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The aim in this study was to develop a model for the probability of finding active golden eagle nests during their breeding season. It was done by using environmental variables derived from expert models which were tested against empirical data. This resulted in a habitat suitability index (HSI), which in this case is assumed to indicate the probability of active nests of golden eagles. The study was conducted together with the County Administrative Board of Västernorrland with the purpose to improve golden eagle’s ecological status.To develop the model, different combinations of several explanatory variables were tested in a model selection process, where the most optimal and parsimonious model was chosen. The tested variables have earlier been shown to affect golden eagles, as slope, aspect, forest age, foraging habitat, suitable flight routes, human population density, roads, railways, power lines, wind power plants, hiking trails and clear cuts. The variables where applied in in ArcMAP at three different scales: nest scale (25 x 25 meter), proximate scale (a circle with the radius of 500 meter) and home range scale (a circle with the radius of 8253 meter). A preliminary test of the variables showed that all golden eagle nests were found in slopes with at least 5֯ degreesas well as in home ranges with human population density not more than 8 people/km2. Due to that a stratified analysis wasperformed. The variables where analysed by multiple logistic regression in R, where the occurrence of golden eagles’ nestswas compared towards random points in the landscape. All variables were also tested one by one by logistic regression. Afterperforming the multiple logistic regression, it was possible to apply its equation into ArcMap to obtain suitability maps withHSI values over Västernorrland’s county.The comparisons of different models show that it is better to combine different spatial scales in the model than only using one spatial scale. The result indicate that three different models might be the best, which all had different combinations of slope and aspect at nest scale and power lines at the proximate scale. Two of these models also include hiking trails and human population density, both at home range scale, in their equation. Since it was some unclarity about the causality between hiking trails and human population density, the conclusion was not to choose any of these as the final model. The final model was more parsimonious and had an additive effect from slope and southern aspect at the nest scale and an antagonistic effect from power lines at the proximate scale.This study clarifies that golden eagles’ habitat preferences for nesting sites during their breeding period is steep slopes (at minimum 5֯ degrees) in more southern aspects with few power lines in the proximate area surrounding the nest. Their homeranges are also situated in areas with less than 8 people/km2. The study also pinpoints a potential conflict between golden eagleand wind power planning, as golden eagles prefer steep slopes and remote areas, which also are valuable areas for wind powerplants. Golden eagles’ preference of remote areas also indicate that they might be affected by human persecution, why certainconservation effort should be focused into this issue. Out from the final model, you can find cluster in the landscape where youcan focus conservation management and restrict exploitation. Due to low number of wind power plants in the landscape, nothingcould be concluded about their effect on golden eagle in this study. An advice from the golden eagle’s perspective is to use theprecautionary principle and further plan wind power plants in areas which already have high disturbance, as for example closeto power lines or roads. The result also indicates that forest age from SLU Forest Map is not suitable for telling where to findgolden eagle nests. GIS-data over forest age would facilitate conservation management for plenty of species connected to theforest.Although good statistical results for the final model, cautions need to be taken in general, since neither population viability analysis have been included, nor changes over time in the landscape. Another issue is the low sample size, where a larger sample size would make it possible to perform profound calibration and validation of the data. To develop a more robust model, the advice is to include these into the model and use a larger sample size.

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Parsapour, Moghaddam Parna. "3D Hydro-Morphodynamic and Fish Habitat Modelling." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38586.

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Meandering rivers provide fresh water and important aquatic ecosystem services, yet at the same time induce flood and erosion hazards. In the face of ongoing development pressure and changing climate, growing concern for meandering rivers has increased the demand to model accurately the flow and predict the sediment transport in a meandering river channel. Calibration and validation of these models based on comparable field-based data, as opposed to laboratory-scale experimental data, may decrease uncertainty and improve understanding of complex flow structures in natural meandering rivers. In this thesis, spatially intensive field data are utilized to develop appropriate calibration and validation methods for 3D meandering river models. Validated models are then applied to the study of morphodynamic processes and the influence of channel change on fish habitat availability in meandering rivers. This study presents a novel methodology for use of three-dimensional (3D) velocity for improved calibration of a 3D hydro-morphodynamic model. A natural tortuously meandering river was simulated using the Delft3D hydrodynamic model. A spatially intensive acoustic Doppler current profiler (ADCP) survey was conducted throughout the study river, providing fully 3D distributed velocities for model calibration. For accurate and realistic comparison of the fully 3D predicted and measured velocities, an algorithm was developed to match the location of each ADCP bin with 3D model grid points. The results suggest that different calibration approaches can result in different calibration parameterizations whose simulated results can differ significantly. It is shown that the model which was calibrated based on the proposed 3D calibration approach had the best model performance. Depending upon the nature and objectives of the numerical modelling exercise, the results demonstrate the importance of model calibration with spatially intensive field data. Given the importance of pressure gradients in driving secondary flow, it is worth studying how the modelled flow structures in a natural river bend can be impacted by the assumption of hydrodynamic pressure. Accordingly, the performance of hydrostatic versus non-hydrostatic pressure assumption in the Delft3D hydrodynamic modelling of a tortuously meandering river was studied. An Acoustic Doppler Velocimeter (ADV) was employed to measure the 3D flow field at a section in a sharp bend of the simulated river at two different flow stages. The field-based ADV data were employed to validate the simulated hydrodynamic models. The results indicate the surprisingly superior performance of the hydrostatic over non-hydrostatic Delft3D modelling of the secondary flow. It was determined that the non-hydrostatic routine employed in Delft3D was not mass conservative, which diminished model accuracy. Despite several decades of intensive study of the morphological changes in meandering rivers, less attention has been paid to confined meanders. This thesis includes a study of the meandering behavior of a semi-alluvial cohesive bed river over a 10-year period. We employed a paired sub-reach study approach, wherein one sub-reach is freely meandering and the second adjacent sub-reach is confined by a railway embankment. Channel migration and morphological changes of the channel banks along each of these sub-reaches were analyzed by comparing the historical aerial photography, light detection and ranging (LIDAR) data, bathymetric data obtained from a total station survey, and field examination. Moreover, two different spatially intensive ADCP surveys were conducted in the study area to find the linkage between the hydrodynamics and morphological changes in the two different sub-reaches. The unconfined sub-reach displayed a typical channel migration pattern with deposition on the inner bank and erosion on the outer bank of the meander bend. On the other hand, the confined sub-reach showed greater bank instabilities than the unconfined sub-reach. In the confined sub-reach, an irregular meandering pattern occurred by the evolution of a concave-bank bench, which was caused by reverse flow eddies. The results of this study could shed light on the potential impacts of channel confinement on bank retreat and river migration in comparable case studies. It is reasonable to expect that hydro-morphodynamic processes in rivers can affect fish habitat availability and quality, but the impact of river morphological changes on fish habitat is not well studied. Herein, we investigate the impact of morphological development of a cohesive meandering creek on the quality of fish habitat available for juvenile yellow perch (Perca flavescens) and white sucker (Catostomus commersonii). A 3D morphodynamic model was first developed to simulate the hydro-morphodynamics of the study creek over a 1-year period. Total station topographic surveys were conducted to provide bathymetric change data for calibration of the morphodynamic module. Successful calibration efforts indicated that the developed model could be reasonably employed to predict the hydro-morphodynamics of the study creek. Two fish sampling surveys were carried out at the beginning and the end of the study period to determine habitat utilization of each fish species in the study reach. ANOVA multiple comparison tests indicate that morphological development of the river was a significant factor for the habitat utilization of juvenile yellow perch, whereas juvenile white sucker habitat utilization was not significantly impacted by the changes in the creek morphology. It is shown that flow depth, depth-averaged velocity, and suspended sediment transport also significantly influenced presence of the juvenile yellow perch at the 5% significant level. As for the juvenile white sucker, the only significant factor was the depth-averaged velocity. The results of the developed 3D hydro-morphodynamic model were fed into a fish habitat model. Comparison of the predicted fish habitat map of the juvenile yellow perch with the results of fish sampling surveys confirms that the habitat quality was better predicted when the impact of morphological changes was taken into account in the fish habitat modelling. The results of the proposed methodology could provide some insights into the impact of sediment transport processes on the fish community. This has important implications for effective river management.

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Sánchez-Ordoñez, Andrés E. "A Markov random fields approach to modelling habitat." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54553.

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Habitat modelling presents a challenge due to the variety of data available and their corresponding accuracy. One option is to use Markov random fields as a way to incorporate these distinct types of data for habitat modelling. In this work, I provide a brief overview of the intuition, mathematical theory, and application considerations behind modelling habitat under this framework. In particular, an auto-logistic model is built and applied to modelling sea lion habitat using synthetic data. First, we explore modelling one sample of data. Afterwards, the framework is extended to the multi-sample scenario. Finally, the theory for the methodology is presented, the results of the applied implementation are presented.
Science, Faculty of
Statistics, Department of
Graduate

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Rose, Craig. "Modelling and measuring the habitat of artificial reefs." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417518.

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Douglas, Sarah Jane. "Habitat suitablity modelling in the New Forest National Park." Thesis, Bournemouth University, 2009. http://eprints.bournemouth.ac.uk/15295/.

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The New Forest National Park is a unique semi-natural landscape which contains many species and habitats which are rare and/or threatened. In order to effectively aid in the conservation of these species, particularly in the face of climate change, there is a requirement to know their habitat requirements and distributions within the New Forest. However, due to limited resources there are gaps in knowledge about this for many of these species. Habitat suitability modelling was carried out to suggest unsurveyed sites of potentially suitable habitat (and consequently higher likelihood of species occurrence) for selected species of high conservation concern (Chamaemelum nobile, Galium constrictum, Gladiolus illyricus, Hipparchia semele, Nemobius sylvestris, Pilularia globulifera, Plebejus argus and Poronia punctata). The performance of several modelling approaches was compared. Of the models based on the use of GIS spatial data, an approach requiring only species presence data (Ecological Niche Factor Analysis (ENFA)) was compared to approaches additionally requiring absence or pseudo-absence data (Generalised Linear Models (GLMs) and Generalised Additive Models (GAMs)). An additional approach that did not require GIS data, Bayesian Belief Network (BBN) modelling, was also used to incorporate finer-scale variables not available in GIS format. This relatively new approach to habitat suitability modelling was also used to predict the potential impact of climate change on the suitability of the habitats for the selected species. The evaluation results showed that the presence-absence GLM and GAM models out-performed the presence-only ENFA method, and that the use of pseudo-absences and automated stepwise variable selection proved effective for developing these models. Species with specialist habitat requirements tended to be modelled more accurately than more generalist species. The BBN models also achieved high evaluation values, and were particularly valuable in being able to provide a quantitative assessment of the potential impact of climate change on the selected species. Habitat suitability modelling at the scale of an individual predicted area of the size of the New Forest has so far been rare, as have predictions of climate change on specific species at this scale. However, the results of this research show that this can be a valuable approach to aid in management and conservation of species and their habitats in protected areas.

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Watkins, Angela. "Spatially-explicit modelling of habitat permeability for mammalian wildlife." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/375423/.

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Least-cost and agent-based models present alternative approaches to modelling animal movements, at the population level and individual level respectively. This study introduces and tests a novel integration of adapted least-cost methods into agent-based simulations, in order to analyse connectivity and habitat preferences in two species of mammal. An initial proof-of-concept study built a set of empirically validated least-cost models of European hedgehogs (Erinaceus europaeus) into a simple agent based model. Agents most closely simulated natural behaviours of dispersing hedgehogs when their movements accounted for temporally-dependent habitat preferences in addition to least-cost pathways informed by the connectivity map. The fitness of these agents increased in more highly fragmented landscapes, in contrast to agents that took least-cost pathways without time-specific preferences. The integration of functional connectivity with individual behaviour combined the advantages of both modelling techniques. Quantitative analysis of the individual-level consequences of moving within different landscape scenarios provides a unique way of applying model outcomes to direct conservation action. A second conceptual study applied integrative methods to the construction of an agent-based simulation scaled for jaguars (Panthera onca) occupying fragmented landscape in Belize. This simulation tested alternative configurations of a wildlife corridor currently under development in Central Belize as part of the intercontinental Mesoamerican Biological Corridor. Six alternative corridor configurations and three control conditions differed substantially in their effectiveness at mixing agents across the environment, despite relatively little difference in individual welfare. Best estimates of jaguar movement behaviours suggested that a set of five narrow corridors may out perform one wide corridor of the same overall area. The first two studies set the framework for developing a detailed simulation of jaguar behaviour and population dynamics in a mixed forest and farmland landscape in the south of Belize. This more complex model drew on empirical data on resident jaguars in the region to simulate typical movement, feeding, reproduction and mortality events within a stable natural population. An overview of the construction and application of the model precedes detailed descriptions of its calibration, sensitivity analysis and validation with empirical data. Agents located inside protected forest reserves exhibited higher fitness, expressed in higher fecundity and lower energy- and habitat-related mortality, than agents located outside these reserves. Model validation showed similar patterns to field data in landscape utilisation and the spatial distribution of individuals. This approach to spatial modelling of population dynamics can provide novel insights into effective conservation strategies for large carnivores. Application of the model to the fragmented central corridor region of Belize sets the context for real-world conservation planning. Under current conditions, simulated jaguars formed a small but stable population with various levels of immigration. Implementation of wildlife corridors showed the largest tracts of physically connected reserves increased connectivity between spatially disconnected habitat patches but also increased vulnerability to environmental degradation.

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Aarts, Geert. "Modelling space-use and habitat preference from wildlife telemetry data." Thesis, St Andrews, 2007. http://hdl.handle.net/10023/327.

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Bellamy, Chloe Charlotte. "Predictive modelling of bat-habitat relationships on different spatial scales." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.550267.

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To develop effective conservation strategies we need to know the ecological drivers of species' distributions at different spatial scales. Geographic Information Systems (GIS) and habitat suitability modelling technology provide us with the tools to examine multiscale, species-habitat relationships. We collected data on the presence of foraging bats from thirty 1 km2 field sites in the south of the Lake District National Park and used the presence-only modelling software MaxEnt to predict foraging habitat suitability across the entire Park (rv3,300 km') for seven species/species groups. Museum records of species' roosts were also used to investigate roost-habitat relationships. Using a moving window analysis we were able to assess the impact of habitat composition and structure over a range of extents (100 m - 6 km). This revealed species- and scale-specific habitat effects. The presence of foraging bats was best predicted by small scale habitat variables, which may reflect the high mobility of these mammals. The strength of roost-habitat associations tended to be more consistent across the range of scales, suggesting that bats may be sensitive to considerable landscape modification's made at great distances from the roost. Each species presence was best predicted by a unique set of enviro-geographic variables. Of the sibling Pipistre//us species, P. pygmaeus had a more narrow niche breadth because of its dependence on high water cover at large spatial scales (1 - 1.5 km) for foraging. Negative impacts of large scale urban cover were detected for P. euntos. Myotis nattereri and M. brandtiijmystacinus, whereas Pipistre//us avoided roosting within large coniferous plantations. Predictions were mapped at a fine resolution across the Park and validated with independent data, revealing that the high density of deciduous and ancient woodland across the southern Low Fells provided good foraging and roosting habitat for all species. This bat "hotspot" should be of high conservation priority.

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Heng, Hannah Yik Siew. "Water quality and habitat modelling in the urban River Tame." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398888.

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Urban river research is scarce. This thesis improves aspects of water quality and physical habitat modelling for sustainable urban river environment management using the highly urbanised River Tame in the West Midlands, UK as study catchment. Specifically, it focuses on modelling at the catchment scale and during high flow discharges. The River Tame system response to rainfall precipitation is complex, with influences from the wastewater treatment acting concurrently with the intricate combined sewer system. The complexity of the system response results in disassociation of critical flows with critical water quality such as biological oxygen demand and ammonium, reinforcing the belief that a design event approach for wet weather flow water quality modelling is impractical. Modelling intermittent discharges on a catchment scale basis through utilisation of a simple water quality model as opposed to sophisticated commercial tools achieved an acceptable level of success. The same order of high flow load magnitudes as field observations was found. Modelling physical habitat availability using a catchment scale methodology, which eliminates the need for intensive field data collection was also demonstrated, suitable for use particularly when water quality and flow regimes are the overriding factors in urban river health. Here, habitat suitability observations from high-resolution simulations over short distances were found to replicate lower resolution simulations over longer distances where cross-sectional shape and channel slope of study reaches are similar. However, with the knowledge of inter-relationships between the flow, water quality and physical habitat remains limited, the development of an integrated management between these different fields is still immature.

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Kopecki, Ianina. "Calculational approach to FST-hemispheres for multiparametrical Benthos Habitat modelling." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-38677.

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Bult, Tammo Peter. "Distribution and habitat use by juvenile Atlantic salmon (Salmo salar) at multiple spatial scales, and implications for habitat modelling and fish-habitat management." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ47493.pdf.

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Stevenson, Claire Denice. "Modelling habitat networks and dispersal in the grey sqirrel Sciurus carolinensis." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582585.

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Broughton, Richard K. "Habitat modelling and the ecology of the marsh tit (Poecile palustris)." Thesis, Bournemouth University, 2012. http://eprints.bournemouth.ac.uk/20768/.

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Among British birds, a number of woodland specialists have undergone a serious population decline in recent decades, for reasons that are poorly understood. The Marsh Tit is one such species, experiencing a 71% decline in abundance between 1967 and 2009, and a 17% range contraction between 1968 and 1991. The factors driving this decline are uncertain, but hypotheses include a reduction in breeding success and annual survival, increased inter-specific competition, and deteriorating habitat quality. Despite recent work investigating some of these elements, knowledge of the Marsh Tit’s behaviour, landscape ecology and habitat selection remains incomplete, limiting the understanding of the species’ decline. This thesis provides additional key information on the ecology of the Marsh Tit with which to test and review leading hypotheses for the species’ decline. Using novel analytical methods, comprehensive high-resolution models of woodland habitat derived from airborne remote sensing were combined with extensive datasets of Marsh Tit territory and nest-site locations to describe habitat selection in unprecedented detail. Further fieldwork established the causes and frequency of breeding failure at the local population scale, and dispersal distances and success were quantified. Information from these studies was used to inform national-scale spatial analyses of habitat distribution in relation to the pattern of range contraction for the Marsh Tit and two other woodland bird species. The combined results indicate that Marsh Tits require extensive areas of mature woodland in order to accommodate large territories and short dispersal distances, with greatest selection for a woodland structure encompassing a tall, near-closed tree canopy and extensive understorey. The evidence suggests that nest-site competition, nest predation or deteriorating habitat quality have not driven the population decline. However, reduced connectivity between woodlands in the landscape, possibly due to hedgerow loss, may have interacted with increased mortality to precipitate population declines and local extinctions where habitat fragmentation was relatively high. The potential causes of increased mortality are discussed, along with priority areas for future research and the wider possible applications of remote sensing techniques in the field of woodland bird research.

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Kynn, Mary. "Eliciting Expert Knowledge for Bayesian Logistic Regression in Species Habitat Modelling." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16041/1/Mary_Kynn_Thesis.pdf.

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This research aims to develop a process for eliciting expert knowledge and incorporating this knowledge as prior distributions for a Bayesian logistic regression model. This work was motivated by the need for less data reliant methods of modelling species habitat distributions. A comprehensive review of the research from both cognitive psychology and the statistical literature provided specific recommendations for the creation of an elicitation scheme. These were incorporated into the design of a Bayesian logistic regression model and accompanying elicitation scheme. This model and scheme were then implemented as interactive, graphical software called ELICITOR created within the BlackBox Component Pascal environment. This software was specifically written to be compatible with existing Bayesian analysis software, winBUGS as an odd-on component. The model, elicitation scheme and software were evaluated through five case studies of various fauna and flora species. For two of these there were sufficient data for a comparison of expert and data-driven models. The case studies confirmed that expert knowledge can be quantified and formally incorporated into a logistic regression model. Finally, they provide a basis for a thorough discussion of the model, scheme and software extensions and lead to recommendations for elicitation research.

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Kynn, Mary. "Eliciting Expert Knowledge for Bayesian Logistic Regression in Species Habitat Modelling." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16041/.

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This research aims to develop a process for eliciting expert knowledge and incorporating this knowledge as prior distributions for a Bayesian logistic regression model. This work was motivated by the need for less data reliant methods of modelling species habitat distributions. A comprehensive review of the research from both cognitive psychology and the statistical literature provided specific recommendations for the creation of an elicitation scheme. These were incorporated into the design of a Bayesian logistic regression model and accompanying elicitation scheme. This model and scheme were then implemented as interactive, graphical software called ELICITOR created within the BlackBox Component Pascal environment. This software was specifically written to be compatible with existing Bayesian analysis software, winBUGS as an odd-on component. The model, elicitation scheme and software were evaluated through five case studies of various fauna and flora species. For two of these there were sufficient data for a comparison of expert and data-driven models. The case studies confirmed that expert knowledge can be quantified and formally incorporated into a logistic regression model. Finally, they provide a basis for a thorough discussion of the model, scheme and software extensions and lead to recommendations for elicitation research.

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O'Leary, Rebecca A. "Informed statistical modelling of habitat suitability for rare and threatened species." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/17779/1/Rebecca_O%27Leary_Thesis.pdf.

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In this thesis a number of statistical methods have been developed and applied to habitat suitability modelling for rare and threatened species. Data available on these species are typically limited. Therefore, developing these models from these data can be problematic and may produce prediction biases. To address these problems there are three aims of this thesis. The _rst aim is to develop and implement frequentist and Bayesian statistical modelling approaches for these types of data. The second aim is develop and implement expert elicitation methods. The third aim is to apply these novel approaches to Australian rare and threatened species case studies with the intention of habitat suitability modelling. The _rst aim is ful_lled by investigating two innovative approaches for habitat suitability modelling and sensitivity analysis of the second approach to priors. The _rst approach is a new multilevel framework developed to model the species distribution at multiple scales and identify excess zeros (absences outside the species range). Applying a statistical modelling approach to the identi_cation of excess zeros has not previously been conducted. The second approach is an extension and application of Bayesian classi_cation trees to modelling the habitat suitability of a threatened species. This is the _rst `real' application of this approach in ecology. Lastly, sensitivity analysis of the priors in Bayesian classi_cation trees are examined for a real case study. Previously, sensitivity analysis of this approach to priors has not been examined. To address the second aim, expert elicitation methods are developed, extended and compared in this thesis. In particular, one elicitation approach is extended from previous research, there is a comparison of three elicitation methods, and one new elicitation approach is proposed. These approaches are illustrated for habitat suitability modelling of a rare species and the opinions of one or two experts are elicited. The _rst approach utilises a simple questionnaire, in which expert opinion is elicited on whether increasing values of a covariate either increases, decreases or does not substantively impact on a response. This approach is extended to express this information as a mixture of three normally distributed prior distributions, which are then combined with available presence/absence data in a logistic regression. This is one of the _rst elicitation approaches within the habitat suitability modelling literature that is appropriate for experts with limited statistical knowledge and can be used to elicit information from single or multiple experts. Three relatively new approaches to eliciting expert knowledge in a form suitable for Bayesian logistic regression are compared, one of which is the questionnaire approach. Included in this comparison of three elicitation methods are a summary of the advantages and disadvantages of these three methods, the results from elicitations and comparison of the prior and posterior distributions. An expert elicitation approach is developed for classi_cation trees, in which the size and structure of the tree is elicited. There have been numerous elicitation approaches proposed for logistic regression, however no approaches have been suggested for classi_cation trees. The last aim of this thesis is addressed in all chapters, since the statistical approaches proposed and extended in this thesis have been applied to real case studies. Two case studies have been examined in this thesis. The _rst is the rare native Australian thistle (Stemmacantha australis), in which the dataset contains a large number of absences distributed over the majority of Queensland, and a small number of presence sites that are only within South-East Queensland. This case study motivated the multilevel modelling framework. The second case study is the threatened Australian brush-tailed rock-wallaby (Petrogale penicillata). The application and sensitivity analysis of Bayesian classi_cation trees, and all expert elicitation approaches investigated in this thesis are applied to this case study. This work has several implications for conservation and management of rare and threatened species. Novel statistical approaches addressing the _rst aim provide extensions to currently existing methods, or propose a new approach, for identi _cation of current and potential habitat. We demonstrate that better model predictions can be achieved using each method, compared to standard techniques. Elicitation approaches addressing the second aim ensure expert knowledge in various forms can be harnessed for habitat modelling, a particular bene_t for rare and threatened species which typically have limited data. Throughout, innovations in statistical methodology are both motivated and illustrated via habitat modelling for two rare and threatened species: the native thistle Stemmacantha australis and the brush-tailed rock wallaby Petrogale penicillata.

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O'Leary, Rebecca A. "Informed statistical modelling of habitat suitability for rare and threatened species." Queensland University of Technology, 2008. http://eprints.qut.edu.au/17779/.

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In this thesis a number of statistical methods have been developed and applied to habitat suitability modelling for rare and threatened species. Data available on these species are typically limited. Therefore, developing these models from these data can be problematic and may produce prediction biases. To address these problems there are three aims of this thesis. The _rst aim is to develop and implement frequentist and Bayesian statistical modelling approaches for these types of data. The second aim is develop and implement expert elicitation methods. The third aim is to apply these novel approaches to Australian rare and threatened species case studies with the intention of habitat suitability modelling. The _rst aim is ful_lled by investigating two innovative approaches for habitat suitability modelling and sensitivity analysis of the second approach to priors. The _rst approach is a new multilevel framework developed to model the species distribution at multiple scales and identify excess zeros (absences outside the species range). Applying a statistical modelling approach to the identi_cation of excess zeros has not previously been conducted. The second approach is an extension and application of Bayesian classi_cation trees to modelling the habitat suitability of a threatened species. This is the _rst `real' application of this approach in ecology. Lastly, sensitivity analysis of the priors in Bayesian classi_cation trees are examined for a real case study. Previously, sensitivity analysis of this approach to priors has not been examined. To address the second aim, expert elicitation methods are developed, extended and compared in this thesis. In particular, one elicitation approach is extended from previous research, there is a comparison of three elicitation methods, and one new elicitation approach is proposed. These approaches are illustrated for habitat suitability modelling of a rare species and the opinions of one or two experts are elicited. The _rst approach utilises a simple questionnaire, in which expert opinion is elicited on whether increasing values of a covariate either increases, decreases or does not substantively impact on a response. This approach is extended to express this information as a mixture of three normally distributed prior distributions, which are then combined with available presence/absence data in a logistic regression. This is one of the _rst elicitation approaches within the habitat suitability modelling literature that is appropriate for experts with limited statistical knowledge and can be used to elicit information from single or multiple experts. Three relatively new approaches to eliciting expert knowledge in a form suitable for Bayesian logistic regression are compared, one of which is the questionnaire approach. Included in this comparison of three elicitation methods are a summary of the advantages and disadvantages of these three methods, the results from elicitations and comparison of the prior and posterior distributions. An expert elicitation approach is developed for classi_cation trees, in which the size and structure of the tree is elicited. There have been numerous elicitation approaches proposed for logistic regression, however no approaches have been suggested for classi_cation trees. The last aim of this thesis is addressed in all chapters, since the statistical approaches proposed and extended in this thesis have been applied to real case studies. Two case studies have been examined in this thesis. The _rst is the rare native Australian thistle (Stemmacantha australis), in which the dataset contains a large number of absences distributed over the majority of Queensland, and a small number of presence sites that are only within South-East Queensland. This case study motivated the multilevel modelling framework. The second case study is the threatened Australian brush-tailed rock-wallaby (Petrogale penicillata). The application and sensitivity analysis of Bayesian classi_cation trees, and all expert elicitation approaches investigated in this thesis are applied to this case study. This work has several implications for conservation and management of rare and threatened species. Novel statistical approaches addressing the _rst aim provide extensions to currently existing methods, or propose a new approach, for identi _cation of current and potential habitat. We demonstrate that better model predictions can be achieved using each method, compared to standard techniques. Elicitation approaches addressing the second aim ensure expert knowledge in various forms can be harnessed for habitat modelling, a particular bene_t for rare and threatened species which typically have limited data. Throughout, innovations in statistical methodology are both motivated and illustrated via habitat modelling for two rare and threatened species: the native thistle Stemmacantha australis and the brush-tailed rock wallaby Petrogale penicillata.

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Sheu, Jia-En. "Modelling habitat preference of corvids (family: corvidae) in Scotland : a landscape perspective." Thesis, University of Aberdeen, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274845.

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Understanding landscape function is one of the core research topics in landscape ecology. Establishing the relative importance of landscape factors and other environmental factors is a key issue. Six members of crow family (Corvidae: jay, Garrulus glandarius; magpie, Pica pica; jackdaw Corvus monedula; rook, Corvus frugilegus; Eurasian crow, Corvus corone; raven, Corvus corax) in Scotland are used to examine these factors. The approach explores the value of the concept of multi-dimensional space in studying habitat. The proportions of different land cover types, the woodland landscape and entire landscape patterns are quantified and tested against the distribution and abundance of corvids. In a specific case study, other environmental factors (elevation, rainfall and temperature) are introduced to help identify the main factors determining the geographic location of the hybrid zone of carrion and hooded crows (Corvus corone corone and C. c. cornix). Finally, a hierarchical model based on path analysis is used to rank environmental variables in terms of their relative influence on species abundance, richness and diversity. The results show that while the diversity of corvid species is strongly correlated with landscape patchiness, the associations between corvid abundance and environmental factors are species specific. The climatic factors are shown to be significant factors in explaining the westward shift of the hybrid zone of carrion and hooded crows over the last 70 years. The habitat requirements of corvids revealed in this study demonstrate a marked contrast with those revealed by studies in continental Europe. These differences are interpreted in terms of the mechanism of habitat shifting.

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Kopecki, Ianina [Verfasser]. "Calculational approach to FST-hemispheres for multiparametrical benthos habitat modelling / von Ianina Kopecki." Stuttgart : Inst. für Wasserbau, 2008. http://d-nb.info/99679557X/34.

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Linstead, Conor. "The influences of large woody debris on British headwater streams." Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368996.

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This thesis examines the influence of large woody debris (LWD) on the physical habitat of British headwater streams. The distribution and density of LWD accumulations throughout catchments is considered using data from the River Habitat Survey (RHS) and more detailed catchment scale surveys. The effect of accumulations of LWD on stream hydraulics and physical habitat at a reach scale is examined using transect based measurements of depth and velocity over a range of discharges before and after LWD removal for two reaches, measurement of reach average hydraulic parameters for 25 reaches with differing levels of LWD and the application of the Aggregated Dead Zone (ADZ) and Physical Habitat Simulation (PHABSIM) models. The RHS and catchment scale surveys showed that LWD accumulations exhibit systematic patterns in abundance within catchments, smaller streams having a higher density of LWD and a greater number of LWD accumulations. The most hydraulically active type of LWD accumulations were found to reduce flow velocity by an average of 55%, increase channel roughness by 149% and increase depth by 165%. This impact was, however, found to vary with discharge. Application of the Aggregated Dead Zone (ADZ) model showed that LWD increases the volume of ADZ, which may indicate greater ecological refuge potential. Using the Physical Habitat Simulation (PHABSIM) model, it was found that LWD improved habitat quality and overall habitat diversity.

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Simpson, Nicola Jane. "Carbon isotopes and the plant fossil record : taphonomic and diagenetic controls." Thesis, Open University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301876.

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Matthews, Thomas James. "Analysing and modelling the impact of habitat fragmentation on species diversity : a macroecological perspective." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:1d71c6fe-06eb-4135-bdb3-874bb273bcb1.

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The destruction and fragmentation of natural habitat is the leading driver of the current extinction crisis. As a result, a research area has emerged focused on studying ecology in islands of natural habitat surrounded by a sea of anthropogenic land uses, so called ‘habitat islands’. However, this research has largely been undertaken on small-medium scales, generally in single systems. Furthermore, many habitat island studies have used previous results and theory derived in the context of oceanic island research. Thus, this thesis aims to examine a variety of macroecological and biogeographical patterns using a large number of purely habitat datasets sourced from both the literature and my own sampling, with the objective of teasing out any general statistical patterns. The various macroecological and biogeographical patterns can be grouped under four broad headings: 1) species–area relationships (SAR), 2) nestedness, 3) species abundance distributions (SADs), and 4) species incidence functions (function of area). Overall, it was found that there were few hard macroecological generalities that hold in all cases across habitat island systems. This is because most habitat island systems are highly disturbed environments, with a variety of confounding variables and undesirable species (e.g. species associated with human land uses) acting to modulate the patterns of interest. Nonetheless, some clear patterns did emerge. In particular, it was found that the power model was by the far the best general SAR model for habitat islands. The slope of the island species–area relationship (ISAR) was related to the matrix type surrounding archipelagos, such that habitat island ISARs were shallower than true island ISARs. Significant compositional and functional nestedness was rare in habitat island datasets, although island area was seemingly responsible for what nestedness was observed. Species abundance distribution models were found to provide useful information for conservation in fragmented landscape, but the presence of undesirable species substantially affected the shape of the SAD. Species incidence function curves were found to vary across space for a given species, but not in any systematic manner. In conclusion, this thesis finds that the application of standard island biogeography theory to habitat islands is too simplistic. It is hoped that the results of this thesis will act as a catalyst for a more macroecological approach to habitat island research, and a starting point for the development of an integrated theory of habitat islands.

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Scales, Kylie Lisa. "The application of ocean front metrics for understanding habitat selection by marine predators." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3319.

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Marine predators such as seabirds, cetaceans, turtles, pinnipeds, sharks and large teleost fish are essential components of healthy, biologically diverse marine ecosystems. However, intense anthropogenic pressure on the global ocean is causing rapid and widespread change, and many predator populations are in decline. Conservation solutions are urgently required, yet only recently have we begun to comprehend how these animals interact with the vast and dynamic oceans that they inhabit. A better understanding of the mechanisms that underlie habitat selection at sea is critical to our knowledge of marine ecosystem functioning, and to ecologically-sensitive marine spatial planning. The collection of studies presented in this thesis aims to elucidate the influence of biophysical coupling at oceanographic fronts – physical interfaces at the transitions between water masses – on habitat selection by marine predators. High-resolution composite front mapping via Earth Observation remote sensing is used to provide oceanographic context to several biologging datasets describing the movements and behaviours of animals at sea. A series of species-habitat models reveal the influence of mesoscale (10s to 100s of kilometres) thermal and chlorophyll-a fronts on habitat selection by taxonomically diverse species inhabiting contrasting ocean regions; northern gannets (Morus bassanus; Celtic Sea), basking sharks (Cetorhinus maximus; north-east Atlantic), loggerhead turtles (Caretta caretta; Canary Current), and grey-headed albatrosses (Thalassarche chrysostoma; Southern Ocean). Original aspects of this work include an exploration of quantitative approaches to understanding habitat selection using remotely-sensed front metrics; and explicit investigation of how the biophysical properties of fronts and species-specific foraging ecology interact to influence associations. Main findings indicate that front metrics, particularly seasonal indices, are useful predictors of habitat preference across taxa. Moreover, frontal persistence and spatiotemporal predictability appear to mediate the use of front-associated foraging habitats, both in shelf seas and in the open oceans. These findings have implications for marine spatial planning and the design of protected area networks, and may prove useful in the development of tools supporting spatially dynamic ocean management.

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Dias, Verónica Raquel Barroso. "Modelação bidimensional de habitats fluviais para espécies piscícolas. Aplicação do Modelo CasimirFish2D." Master's thesis, ISA, 2013. http://hdl.handle.net/10400.5/6119.

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Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia
Habitat degradation associated with river regulation, consequence increasing human demands on water resources, and result is changed richness and diversity fish species. Projects ecological habitat to improve becomes a priority for authorities in many countries. In the present study, a methodology based on the relationship between fish habitat and stream flows, is applied in order to determine impact the regulate flows to species. A new approach based on fuzzy sets and rules, linguistic rules describe the imprecise information which often characterizing ecological data and enable implementing the interactions between physical variables. The habitat selection of several species can be predicted adequately based on expert knowledge. Analyzed the Odelouca River, in the south-west of Portugal, when applied the CasimirFish2D model habitat to a stream downstream Odelouca Dam and the fish habitat was determined for two endemic cyprinids species, Iberian chub (Squalius aradensis) and Iberian nase (Iberochondrostoma almacai). The results validated that decrease in availability habitat exists, and changes according to ontogeny. Casimir is a good alternative to others habitat models and may be having a good applicability in fluvial restoration studies.

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Perich, Brad C. "Angiostrongylus cantonensis| Epidemiologic Review, Location-Specific Habitat Modelling, and Surveillance in Hillsborough County, Florida, U.S.A." Thesis, University of South Florida, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10748579.

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Angiostrongylus cantonensis is a parasitic nematode endemic to tropical and subtropical regions and is the leading cause of human eosinophilic meningitis. The parasite is commonly known as rat lungworm because the primary host in its lifecycle is the rat. A clinical overview of rat lungworm infection is presented, followed by a literature review of rat lungworm epidemiology, risk factors, and surveillance projects. Data collected from previous snail surveys in Florida was considered alongside elevation, population per square kilometer, median household income by zip code territory, and normalized difference vegetation index specific to the geographic coordinates from which the snail samples were retrieved. The parameters of interest were incorporated as possible predictor variables in a Poisson probability regression model and a negative binomial regression model. NDVI and population density were determined to be positively associated with number of snail samples positive for A. cantonensis in a given Miami-based location. A surveillance project was conducted in Hillsborough County, Florida, U.S.A.. Snail samples were collected and tested for A. cantonensis DNA via polymerase chain reaction (PCR) and gel electrophoresis. None of the samples tested positive for A. cantonensis.

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Perich, Brad Christian. "Angiostrongylus cantonensis: Epidemiologic Review, Location-Specific Habitat Modelling, and Surveillance in Hillsborough County, Florida, U.S.A." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7216.

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Angiostrongylus cantonensis is a parasitic nematode endemic to tropical and subtropical regions and is the leading cause of human eosinophilic meningitis. The parasite is commonly known as rat lungworm because the primary host in its lifecycle is the rat. A clinical overview of rat lungworm infection is presented, followed by a literature review of rat lungworm epidemiology, risk factors, and surveillance projects. Data collected from previous snail surveys in Florida was considered alongside elevation, population per square kilometer, median household income by zip code territory, and normalized difference vegetation index specific to the geographic coordinates from which the snail samples were retrieved. The parameters of interest were incorporated as possible predictor variables in a Poisson probability regression model and a negative binomial regression model. NDVI and population density were determined to be positively associated with number of snail samples positive for A. cantonensis in a given Miami-based location. A surveillance project was conducted in Hillsborough County, Florida, U.S.A.. Snail samples were collected and tested for A. cantonensis DNA via polymerase chain reaction (PCR) and gel electrophoresis. None of the samples tested positive for A. cantonensis.

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Randall, Joanne. "Estimating productivity in habitat-forming seaweeds." Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/271489.

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Macroalgal beds provide the ecological foundations for most shallow reef ecosystems in temperate environments. With distinctive canopies primarily of brown laminarian algae (northern hemisphere), or laminarian or fucalean algae (southern hemisphere), in many areas these habitats are at risk from human activity. Overexploitation, pollution, and other effects of coastal activities have resulted in significant habitat loss in coastal ecosystems, and human-induced climate change is now seen as a major threat to ecosystem health in marine systems. Understanding the impact of climate change is particularly important for habitat-forming ecosystem engineers like kelps, as these species form the basis of hierarchically organised communities and play a fundamental role in determining community structure and ecological processes. South eastern Australia has experienced increases in marine temperatures at nearly four times the global average, and there is now evidence that, in some locations, macroalgae communities are retreating in a manner consistent with ocean warming. Successful management of marine systems requires understanding ecosystem processes, particularly the patterns and magnitude of production. Macroalgal communities often show relatively low resistance to disturbance, yet rapid recovery once disturbances are removed, hence they are generally highly dynamic in response to environmental perturbations. As a result, macroalgae are likely to play an increasingly important role in buffering the short term/dynamic effects of climate change on temperate reef communities.Knowledge of the productivity of seaweed-dominated temperate reef systems is largely a synthesis from studies conducted over small spatial scales utilising a variety of methods that generally measure different characteristics of both individual seaweeds and collectively. As a result of the diversity of measurement methods, estimates of gross primary productivity (GPP), production potential, and macroalgal biomass for temperate reefs are numerous and variable. This can lead to challenges for ecologists attempting to amalgamate research findings to facilitate long-term, broad-scale perspectives or compare short-term research between spatially separated communities. However, to date there has been relatively little research to compare measurement approaches and quantify differences in productivity estimates across the different techniques.The present research provides a unique investigation into some of the techniques and methodology involved in measuring primary productivity in marine systems, particularly kelp forests, using the macroalgae Ecklonia radiata, Phyllospora comosa and Macrocystis pyrifera as study species. The work is based on both field and laboratory exploration of productivity measurements and associated parameters. In situ measurements of primary productivity (diel oxygen modelling, benthic oxygen exchange chambers) or PSII electron transport (PAM fluorometry) are compared, and the possibility of using acoustics as a means of quantifying oxygen production at large scales is explored, as has already been applied in seagrass beds. This thesis also provides an in depth investigation of the effect of variability in sampling methodology with regards to interpretation of PAM fluorometry-derived parameters. Chapter 2 investigates the acoustic properties of Ecklonia radiata. The density, sound speed and resulting adabiatic compressibility of E. radiata tissue were investigated in the laboratory. Four methods were developed and trialled to determine the intrinsic sound speed of Ecklonia radiata tissue based on measurement of the time of flight of an ultrasonic pulse, while compressibility was calculated from density measurements. The results show that Ecklonia radiata sound speed and density are higher, and compressibility lower, than that of seawater. Properties varied according to size and tissue type and the variation likely reflected differences in cell type, packing and structure as well as the concentrations of alginates and other carbohydrates. These are important considerations for acoustic propagation and the results provide valuable inputs for future acoustic work. Chapter 3 focuses on the acoustic modelling of different scenarios of primary production in a shallow water rocky reef environment of Fortescue Bay (Canoe Bay), Tasmania, where E. radiata dominates the canopy. In February 2012, the environment was continuously probed by acoustic signal transmission and monitored by a comprehensive set of oceanographic sensors with the aim to assess the potential for acoustics to quantify excess oxygen production in bubble form. Ray-theory acoustic modelling results indicate that ecologically-significant void fractions of oxygen in the canopy layer from production would be clearly seen in diel variation of propagation features such as the energy decay rate of the medium impulse response. The model can then be used to invert empirical data for retrieving void fraction. However, comparative analysis of part of FORTES 12 data and model suggests that no large excess of bubbles was produced by photosynthesis under the present environmental conditions, in contrast to earlier observations made in seagrasses. As a result, the use of acoustics as a means of measuring primary productivity in kelp could not be further explored during the course of this research.Chapter 4 provides a unique comparison of the estimates of photosynthetic O2 production rates in an Ecklonia radiata dominated community using three different measurement methods: diel oxygen GPP models, benthic oxygen exchange chambers, and electron transport rate from PAM fluorometry which is usually interpreted as a measure of production potential. All three methods were run concurrently in situ in Fortescue Bay, Tasmania. The first diel oxygen model was fitted to in situ measures of dissolved oxygen (DO) in the environment and demonstrated a good fit, however, a consequence of this approach is that large variation in oxygen production was predicted at low PAR levels. A second model was created which utilised an explicit relationship between DO production and PAR, but it didn’t represent DO at the surface as well as the first model. Importantly, the two models indicate similar daily production rates of the seaweed bed (all species combined) that are ~ 2 times that predicted for the kelp alone based on incubations in the benthic chambers and scaling for the average size of adult kelp sporophytes and their population density. Oxygen evolution from incubation of sporophytes in benthic chambers and PAM fluorometry derived electron transport rates showed similar patterns, but the results indicate that the latter method may overestimate potential photosynthesis. The results suggest that diel oxygen modelling, benthic oxygen exchange chambers and PAM fluorescence can all provide good indications of productivity in shallow water marine environments. However, care must be taken in interpretation of results as each method differs in the type of productivity estimates it provides. As a direct measure of total seaweed production per unit area of reef, estimates from models based on empirical measures of environmental DO have much to recommend them.Chapter 5 details a final analysis investigating the effects of diurnal, seasonal and latitudinal variability in ambient light on PAM-derived parameters, as well as possible effects associated with depth, within- and between-alga variation in PSII performance, and latitudinal effects unrelated to the light climate. This research was based on field measurements undertaken in Tasmania, Western Australia and New South Wales, Australia in both summer and winter during 2012 and 2013, focussing on Ecklonia radiata, Macrocystis pyrifera and Phyllospora comosa. Photosynthetic characteristics of all species were highly dependent on the time of day, depth, latitude/region, season, and part of the thallus from which measurements were taken. Patterns dependent on time-of-day, depth and thalli placement varied with season and/or geographic region, and the nature of these patterns varied between species. It is clear from this work that efforts to standardise approaches to taking measurements of seaweeds using PAM fluorometry will be essential if measurements are to be compared meaningfully across studies.The key findings of this thesis are: (1) a first determination of the acoustic properties of E. radiata tissue which enable the development of scattering models to interpret scientific echosounder data collected in kelp beds; (2) a Gaussian beam/finite element beam code (Bellhop) with detailed environmental input and a huge number of beams can predict the acoustic character of a shallow water rocky reef and bubble layers with low-frequency effective sound speed; (3) the model allows prediction of the acoustic energy decay rates due to various scenarios of ecologically-relevant photosynthetic O2 production rates; (4) day vs night acoustic measurement and model data comparisons challenge void fraction predictions made from well established measurements and methods; (5) diel oxygen modelling, benthic oxygen exchange chambers and PAM fluorescence can all provide good indications of productivity, however, understanding the limitations of each method is essential when interpreting the results as the measurements they provide are not directly comparable; and (6) applying a consistent sampling methodology is a key consideration when planning research utilising PAM fluorometry as diurnal, seasonal, and latitudinal variability, as well as effects associated with depth and within- and between-alga variation in PSII performance will have significant impact on PAM-derived parameters. The results of this work give valuable insight into the advantages and disadvantages involved with several main techniques currently utilised to measure production of macroalgal/seagrass beds, and the challenges faced by ecologists attempting to interpret results and compare research between methods and across studies. Last but not least, this study provides important and relevant information on the potential use of acoustics as a future means of determining productivity of benthic habitat on large scales in marine environments. The work presented herein will assist in both development and interpretation of future study of productivity in marine systems.
Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished

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Gkaraveli, Anthi G. "Forest conservation, expansion, restoration and management in a National Park : modelling ecology, suitability, biodiversity priorities, temporal and climate change using GIS and spatial data." Thesis, Bangor University, 2002. https://research.bangor.ac.uk/portal/en/theses/forest-conservation-expansion-restoration-and-management-in-a-national-park--modelling-ecology-suitability-biodiversity-priorities-temporal-and-climate-change-using-gis-and-spatial-data(76501537-4b60-449a-98a0-24a08d971599).html.

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When maintaining the biodiversity and ecological integrity of forests is a goal of management, a primary requirement is to assess the status, condition, conservation value of each forest, and change in forest conditions over time. GIS procedures were used here to compare different map-based surveys and look in detail at changes in woodlands of the Snowdonia National Park, North Wales, from 1970 to 2000. The maps from the 1970s and 1980s generated by Silsoe College did not compare well with the map from the 1990s produced by the Forestry Commission and no meaningful changes could be measured. This was attributed to difficulties with comparison of different interpretations and classification schemes used by the two organisations. A series of landscape surveys using the same minimum mapping unit, classification scheme, and methodology in general is needed. The potential changes in broadleaved and scrub woodland area were modelled based on the two most extreme climate change scenarios, termed the Low and High scenarios. Temperature and rainfall models formed the basis for logistic regressions of woodland type and distribution. A declining trend in probability of presence for both woodland types from the present sites was shown under the UKCIP98 High climate change scenario. The results emphasized the conceptual difficulties in using fragments of woodland within the realised niche rather than the fundamental niche as the basis for environmental modelling of plant community distributions. GIS based models were generated to address the key question in the biodiversity action plan process of where should new woodland be created or plantations restored. Ecological criteria were developed to identify the priority areas for native woodland expansion taking into account of the requirements for successful woodland expansion from the nature point of view and specific policy aims. The results were interesting and suggested that there is ample land potentially suitable in Snowdonia for new native woodland. The models could be used to aid decision-making for new native woodland in the National Park. A further extension of GIS-based modelling was developed for the prediction of individual NVC types and BAP priority woodland types. The environmental spaces occupied by the fragments of NVC woodland types currently present in Snowdonia were defined and used as templates to produce maps of potentially suitable sites for the occurrence of each NVC type. The results were not as clear-cut as had been hoped because of overlaps in the predicted occurrences of various woodland types. Independent verification of the predictions using non-spatial data for 24 sites revealed that the model produced was very poor. This was not, however, a fault of the modelling but a reflection of the fact that some of the environmental data were at too coarse a scale and that NVC types are not solely determined by environmental factors. In spite of some weaknesses in the data, the use of GIS for modelling these scenarios proved useful. Nowadays, forest policies in Wales, Europe and elsewhere are changing rapidly to meet modified global, national, and local objectives. GIS is, and will increasingly be so, proving to be a useful and flexible tool for translating forest policy into practical application on the ground.

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Williams, Matthew R. "Diversity of butterflies and day-flying moths in urban habitat fragments, south-western Australia." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/1757.

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This study adapted and developed methods of assessing and modelling biodiversity of butterflies and day-flying moths in habitat fragments, and determined those factors affecting their presence, abundance and species richness in a sample of 46 isolated urban remnants in south-west Western Australia. The specific objectives were to: (i) assess the effectiveness of transect–based sampling to quantify the species richness of habitat fragments; (ii) examine patterns of species richness in habitat fragments and quantify the detectability of each species recorded; (iii) review and rationalize the methods used to fit species–area–habitat models; and (iv) model species incidence, abundance and total richness of butterflies in urban habitat fragments and determine implications and priorities for their conservation.These objectives were achieved and the principal findings of the research are: (i) The transect method provides an accurate assessment of butterfly species richness in isolates provided that the level of sampling (proportion of area surveyed) is adequate, that sufficient surveys are conducted during the flight season to ensure high levels of detectability, and that surveys are conducted at appropriate times and during suitable weather conditions. Although randomly placed transects are preferable, logistic constraints often dictate the use of existing pathways, roadsides or management tracks – which requires the use of longer transects but is more practical in urban remnants.(i) The transect method provides an accurate assessment of butterfly species richness in isolates provided that the level of sampling (proportion of area surveyed) is adequate, that sufficient surveys are conducted during the flight season to ensure high levels of detectability, and that surveys are conducted at appropriate times and during suitable weather conditions. Although randomly placed transects are preferable, logistic constraints often dictate the use of existing pathways, roadsides or management tracks – which requires the use of longer transects but is more practical in urban remnants.(iii) Almost a century of fitting species–area curves has failed to produce agreement on which function is the best model of the relationship. Many of the proposed functions are identical, special cases of others or have arisen from transcription errors. Empirical comparison of these functions requires methods suited to the distribution of species number such as the generalized linear model, method of maximum likelihood and the information-theoretic approach, and proper attention to covariates and their interactions.(iv) Site area and vegetation condition were the dominant determinants of the presence, abundance and total species richness of resident butterflies and day-active moths in 46 urban habitat fragments in south-west Western Australia. Larger sites with more high quality (undisturbed) vegetation favoured 16 of 20 native species and only one benefited from disturbance. A further nine species not sufficiently widespread or abundant to enable individual analysis were collectively more prevalent in larger sites. Resource quality and quantity dominated the patterns of site occupancy, and increased site connectivity did not favour any species – results consistent with habitat resources, not metapopulation effects, determining current distribution patterns. As expected, the presence of non-resident species was unaffected by site area. The total number of resident species at each site reflected the collective responses of the individual species: increasing with area and declining with vegetation disturbance. The effects of area and vegetation quality were not simply additive: disturbance had a far greater impact on small remnants. This interaction is inconsistent with the area per se hypothesis: in the absence of disturbance there was no evidence of a species–area effect.This study is the first comprehensive, quantitative assessment of the distribution and ecology of butterflies and day-flying moths in Australian urban habitat fragments and provides a baseline against which future changes in species distributions may be measured. The results have important implications for the conservation of butterflies and day-flying moths in the region. Maintenance of vegetation quality is of paramount importance and is vital in smaller remnants. Large remnants, being less susceptible to local extinctions, will be essential for the persistence of many species. Many functions have been proposed to model the species–area relationship but empirical comparisons have been hindered by methodological problems – this study conducted a re-examination of the relationship and presents an appropriate framework to compare functions. This study is also one of few to demonstrate and quantify the importance of interactions in explaining patterns of species richness and should stimulate future research into the importance of these effects.

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Tourne, Daiana Carolina Monteiro. "Combining species distribution modelling and environmental perceptions to support sustainable strategies for Amazon-nut (Bertholletia excelsa Bonpl.) planting and conservation." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-14032019-160707/.

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The amazon ecosystems have been compromised by historical forms of occupation and land-use causing habitat loss and forest fragmentation. These anthropogenic disturbances associated to climate changes have direct consequences on the distribution of species and their in situ persistence. Currently, 76 of 14.003 plants taxonomically identified in the Amazon have been listed by the Brasilian Ministry of the Environment as threatened species, though we believe this number to be much bigger in the reality. Among them, Amazon-nut (Bertholletia excelsa), a native tree species, national and internationally known for its cultural, social-economic and nutritional value has been classified as vulnerable. For developping of public policy turned to its management and conservation is fundamental to know the percentage of habitat available, as well as the nature and scale of threats to this environments. Species distribution modelling is an increasingly important tool for predicting habitat suitability and for understanding species environmental tolerances, but has been rarely used in Brazil, especially for Amazonian species. This study aimed to model the potential distribution of B. excelsa in the Amazon biome and to know the factors that control its distribution. To enhance our analysis, case studies were carried out with stakeholders aiming to know their perceptions about the main threats to the species and potential solutions.This research project was based on two hypotheses: (i) There is a suitable habitat to Amazon-nut which require different objectives for conservation and planting; (ii) If the local people are aware of the species vulnerability, they are able to point out the factors that cause this condition. In the chapter 1, habitat was investigated using MAXENT algoritm. We collected 3,325 Amazon-nut records and organized one hundred-and-two environmental variables into climatic, edaphic and geophysical categories at a spatial resolution of 30 arcs-second (~1km). Multi-colinearity between variables was dealt with multivariate statistics associated to expert\'s knowledge, and presence data biased with the spatial filtering. The best model was selected adopting quantitative metrics and visual examination. The most importante biophysic variables we identified were: altitude (m), coarse soil fragments (<2mm) and clay (%). Finaly, the best model indicated 2.3 million km2 i.e., 32% of the Amazon basin has potential for B. excelsa to grow. In the chapter 2, the factors that affect Amazon-nut conservation and planting were discussed with local communities, public managers and researchers, totalyzing 203 participants. Focus groups, individual interviews and questionaire techniques were used to gather information. Data were categorized and the perceptions among stakeholders compared using quali-quantitative analyses. We found that there are currently 36 problems responsible for the species vulnerability and 72% of them belong to environmental and political contexts. Deforestation was the main problem mentioned, followed by fruit depreciation, control failures and lack of organization in the communities. For three groups of stakeholders, the main solutions were related to political context. The results obtained in this study contribute to increase ecological knowledge on the species, to demonstrate the complexity of sustainable use in the Amazon and to guide decisions makers in the selection of priority areas for conservation and potential planting.
Os ecossistemas amazônicos vêm sendo impactados ao longo dos anos por diversos processos de uso e ocupação do território, os quais têm resultado em perdas de habitats e na fragmentação da paisagem nativa. Essas perturbações antrópicas, associadas às mudanças climáticas, têm consequências diretas sobre a distribuição e persistência das espécies in situ. Das 14.003 plantas da Amazônia reconhecidas taxonomicamente, somente 76 estão atualmente listadas pelo Ministério do Meio Ambiente brasileiro como espécies ameaçadas, embora acredita-se que esse número seja muito maior. Entre elas, a Castanha-da-Amazônia (Bertholletia excelsa), uma espécie de árvore nativa, reconhecida nacional e internacionalmente pela sua importância cultural, socioeconômica e nutricional, encontra-se classificada como vulnerável. Para nortear políticas públicas na conservação e no plantio dessa espécie, um profundo entendimento sobre o habitat disponível para ela, bem como a origem e escala das ameaças à esse ambiente, é necessário. A modelagem de distribuição de espécies é uma ferramenta que oferece predições espaciais robustas sobre a adequabilidade de habitat e tolerância das espécies, mas tem sido pouco utilizada no Brasil, sobretudo para espécies Amazônicas. Nesse contexto, esse estudo objetivou modelar a distribuição potencial da B. excelsa no bioma Amazônia, bem como conhecer os fatores que controlam sua distribuição. Para aprofundar essas análises, estudos de caso foram realizados com o objetivo de conhecer a percepção de atores sociais envolvidos com a espécie sobre as principais ameaças e potenciais soluções. Essa tese baseou-se em duas hipóteses: (i) existem áreas com maior adequabilidade para a ocorrência da Castanha-da-Amazônia que demandam diferentes objetivos, para conservação e para o plantio; (ii) se a população local é conciente da vulnerabilidade da espécie, ela pode indicar os fatores que geram essa condição. No capítulo 1, o habitat foi investigado por meio de simulações usando o algoritmo MAXENT. Um total de 3.325 ocorrências e 102 variáveis ambientais foram obtidas, e posteriormente organizadas por categorias climática, edáfica e geofísica. A resolução espacial escolhida foi de 30 arc-segundo (~1km). A multi-colinearidade entre as variáveis foi reduzida por meio da estatística multivariada associada ao conhecimento de especialistas, e as tendências nas ocorrência foram tratadas através da filtragem espacial. O melhor modelo foi selecionado usando métricas quantitativas e examinações visuais. As variáveis biofísicas mais importantes encontradas foram altitude (m), solos com fragmentos grosseiros (<2mm) e argila (%). Por fim, o modelo indicou que 2.3 million km2 i.e., 32% da região amazônica é apropriado para B. excelsa crescer. No capítulo 2, os fatores que afetam a conservação e o plantio da espécie foram discutidos com comunidades, gestores e pesquisadores locais, totalizando 203 participantes. As técnicas de discussão em grupo focal, entrevistas individuais e questionários foram utilizadas para a coleta das informações. Os dados foram categorizados e as opiniões entre os diferentes grupos comparadas utilizando análises quali-quantitativas. Concluiu-se que atualmente existem 36 problemas responsáveis pela vulnerabilidade da espécie, dos quais 72% encontram-se no contexto ambiental e político. O desmatamento foi a principal forçante apontada, seguida pela desvalorização do fruto, falhas na fiscalização e falta de organização nas comunidades. Para os três grupos, as principais soluções foram voltadas para o contexto político. Os resultados obtidos nesse estudo contribuiem para aumentar o conhecimento ecológico da espécie, para demostrar a complexidade do uso sustentável na Amazônia, e orientar tomadores de decisão na seleção de áreas prioritárias para conservação e potenciais para o plantio.

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Bellu, Annalisa. "Phytosociology applied to wildlife management - a study on the potentiality for the reintroduction of cervids in the Montemuro-Freita-Arada mountain range." Doctoral thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5215.

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Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia
The aim of the present thesis was to assess the use of phytosociology in wildlife management. In Section II, as a case study, I investigated red deer (Cervus elaphus hispanicus) and roe deer (Capreolus capreolus) free ranging populations occurring in the Natural Park of Montesinho, northeast Portugal, using faecal-pellet counts to assess deer use of semi-natural meadows (lameiros) and forest communities. Phytosociological classification contributed to explain red deer spring selective use of meadows at finer scales and performed better than other clustering criteria for classifying vegetation patches. At the landscape level, composition of the neighbouring vegetation mosaic, topography, and meadow’s characteristics, as management status and dominant phytosociology, produced the best models for deer seasonal use of meadows. The forest use analysis revealed red and roe deer preference for oak forests over pine plantations, and habitat use overlapping between red and roe deer all year round. In Section III, I extrapolated the information gathered in Section II on deer use to build, for the Montemuro-Freita-Arada massif, a predictive map for roe deer use of meadows, showing a generally low use, with exception of isolated meadows closer to oak forest patches

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Antonia, Galanaki. "Modelling the breeding habitat of the lesser kestrel falco naumanni in an agricultural landscape in Central Greece." Thesis, Manchester Metropolitan University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533357.

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The lesser kestrel Falco naumanni is a globally threatened falcon which, in Europe, is mainly restricted to the Mediterranean Basin. Its populations in Western Europe have undergone a rapid decline by ca. 95% since the 1950s and although it used to be one of the most abundant falcons in Europe in the 1970s, it is now extinct from central Europe and very rare in many other countries. The current European breeding population of the lesser kestrel is estimated at 25,000-42,000 breeding pairs, with Spain, Italy and Greece supporting the largest populations. It breeds in colonies in towns and villages and forages in steppe-like habitats, such as grasslands and plains with low-intensity cultivation. The main cause of its decline in Europe has been habitat loss and degradation, primarily as a result of agricultural intensification and other land use changes. The main aim of the present study, conducted during the years 2005-2007, was to identify environmental attributes related to lesser kestrel occurrence and abundance in agricultural areas in Central Greece. A second aim was to detect land cover changes and evaluate their impact on lesser kestrel breeding grounds, following the implementation of the Common Agricultural Policy (CAP) of the European Union (EU). Species Distribution Models (SDMs) were used to understand and predict the spatial distributions of lesser kestrels. These models have become a fundamental component in ecology and conservation biology and have been used to examine the occurrence and abundance of species, to forecast how species would respond to land use changes and to select areas for conservation planning. The study area is located in the plain of Thessaly, in Central Greece which holds the main breeding populations of lesser kestrels in the country. It consists of agricultural land dominated by irrigated cotton and dry cereal fields, open hilly areas with grasslands and is surrounded by mountains. The lesser kestrel breeding distribution was mapped during the years 2005-2007. Predictive spatial distribution models were developed from the species presence/absence data and environmental information including land cover, topography, landscape structure and human population. The performance of different statistical approaches, a parametric (Generalised Linear Model), a semi-parametric (Generalised Additive Model) and a non-parametric model (Random Forest) was also evaluated. The quality of agricultural areas as foraging habitats for the lesser kestrel during the chick rearing period was assessed using Multiple Regression & Poisson Regression Models and a habitat selection analysis (Neu's method). Satellite images were used to detect landscape changes over a period of 30 years (1977,1992,1999 and 2006). The results of the statistical models agree with the findings of previous habitat-based studies which highlight the importance of low input farming systems for the occurrence of lesser kestrel breeding colonies. The predicted probability of lesser kestrel occurrence at the large scale analysis is positively associated with farmed landscapes of both dry and wet arable cultivations. With respect to prediction accuracy, there is little to choose between the models and reduction in testing accuracy is relatively small suggesting that all models are robust. The foraging habitat analyses at the fine-scale reveal the importance of non-irrigated arable land, grassland, fallow land and pastures as optimal feeding sites for lesser kestrels in the study area. Abundance of foraging birds is negatively associated with irrigated farmland, scrubland and woodland. Electricity wires and poles, used as foraging perches, is a significant predictor for the species abundance in most models. The analysis of land-use changes showed that traditional cereal farming has been reduced, while cotton production has increased in the study area, particularly during the 1990s; a development driven by the farming practices implemented through CAP reforms of the EU. Agricultural areas, such as dry cereal cultivations, that support rare species are considered as `high-naturevalue (HNV) farmland' and are of great importance for the preservation of biodiversity in Europe. Overall, the main conservation priority for the conservation of lesser kestrel in the plain of Thessaly is the maintenance of low-input farming systems and the implementation of a greener CAP that would promote environmental-friendly farming practices and preserve wildlife in agricultural ecosystems

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Fabris, Luca. "Influence of hydrology, hydraulics and temperature on Atlantic salmon habitat : modelling-based approaches for sustainable river management." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239262.

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In this thesis, we improved our understanding of the effects of hydrology, stream hydraulics, and temperature on juvenile Atlantic salmon (Salmo salar L.) habitat. We demonstrated the key role played by stream morphology and flow regime on in-channel hydraulics and consequently on salmonid habitat. Additionally, we showed how riparian afforestation has potential to moderate climate change effects on stream temperature preserving freshwater ecosystems. The Girnock Burn is an upland Scottish river that has been intensively studied to investigate flow generation processes and stream temperature, and has served as a long-term monitoring site for Atlantic salmon population dynamics since 1966. The general approach applied consisted of combining different types of models including: hydraulic, fish habitat, hydrological and heat transfer models with long-term hydrological and climatic data sets, and digital terrain models (DTMs) at different spatio-temporal scales. Our results showed that the extensive presence of roughness elements (e.g. boulders and cobbles) is capable to provide some refuge areas for juvenile salmon fry for a wide range of flows. However, under extreme flow conditions, in-channel hydraulics might represent a limiting factor. Significant inter-site differences occurred and were consistent throughout the years. Evidence of long-term trend in fry habitat quality could be identified only in summer. Since more extreme flow regimes are expected in the future as a result of climate change, we also proposed a novel analytical approach that allowed us to assess the effects of hydroclimatic variation on fish populations outside the range of observations. Finally, we showed the potential of afforestation to reduce daily stream temperature range, moderating both low and high peaks of more than 2 ○C. This makes riparian shading a valuable mitigation strategy to contrast global warming effects on stream temperatures that should be considered for a sustainable catchment management.

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Nimick, Aileen Margaret. "Modelling Fishing Gear to Address "More than Minimal and Not Temporary" Fishing Effects to Essential Fish Habitat." Thesis, Alaska Pacific University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10845718.

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The Magnuson-Stevens Fishery Conservation and Management Act (MSA; Magnuson-Stevens Fishery Conservation and Management Act. 2014. (16 U.S.C. 1801–1891(d)) mandates that fisheries management councils in the United States prevent adverse, or “more than minimal and not temporary”, fishing effects to essential fish habitat (EFH) to the extent practicable. Councils were left to decide what effects qualified as “minimal” and “temporary”. The lack of explicit definition in the MSA and its accompanying Final Rule has resulted in inconsistent habitat management throughout the country. The EFH mandate was written under an implicit assumption that councils have the scientific information necessary to effectively manage EFH. Basic information is lacking, such as what type of habitat occurs where, and how fishing effects habitat features. Chapter 1 briefly reviews the history of EFH regulation, the consequences of regulatory ambiguities and information gaps, and highlights that high latitude fisheries management can be disproportionately affected by climate variability. Thus, requiring investment in baseline habitat assessment and monitoring and renewed focus on under developed areas of research e.g. Fishing effects and gear-habitat interactions.

Councils have attempting to quantitatively describe fishing effects to EFH through the use of mathematical models. The most recent of which, the Fishing Effects (FE) Model, was used in the North Pacific Fisheries Management Council 2015 EFH Review cycle. The FE Model uses discrete time steps (monthly) and spatially explicit fishing effort and sediment data to calculate an estimated habitat disturbance. The FE Model is calculated in two-dimensions and implicitly assumes that if fishing gear does not contact the seabed, then there is no gear-habitat interaction. Some features stand taller than raised gear (e.g. sea whips, Halipteris willemoesi, in the North Pacific can up to 2m tall) and may interact with fishing gear. The FE Model in two-dimensions does not account for this potential interaction and cannot effectively simulate gear modifications. Chapter 2 proposes an adapted version of the FE Model that accounts for the vertical interactions through the use of discrete height bins. To accurately estimate interactions on and above the seabed, fishing gear has to be recharacterized. To demonstrate this the Bering Sea flatfish trawl was recharacterized by calculating how much of the nominal gear width is present in each height bin. A detailed methodology is provided to allow this method to be applied to any fishing gear. The adapted FE Model can be used to simulate gear modifications, as is shown by simulating two modifications of the flatfish trawl. This chapter will inform the 2020 EFH Review cycle as the FE Model is improved.

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Williams, Matthew R. "Diversity of butterflies and day-flying moths in urban habitat fragments, south-western Australia." Curtin University of Technology, Department of Environmental Biology, 2009. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=129025.

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This study adapted and developed methods of assessing and modelling biodiversity of butterflies and day-flying moths in habitat fragments, and determined those factors affecting their presence, abundance and species richness in a sample of 46 isolated urban remnants in south-west Western Australia. The specific objectives were to: (i) assess the effectiveness of transect–based sampling to quantify the species richness of habitat fragments; (ii) examine patterns of species richness in habitat fragments and quantify the detectability of each species recorded; (iii) review and rationalize the methods used to fit species–area–habitat models; and (iv) model species incidence, abundance and total richness of butterflies in urban habitat fragments and determine implications and priorities for their conservation.
These objectives were achieved and the principal findings of the research are: (i) The transect method provides an accurate assessment of butterfly species richness in isolates provided that the level of sampling (proportion of area surveyed) is adequate, that sufficient surveys are conducted during the flight season to ensure high levels of detectability, and that surveys are conducted at appropriate times and during suitable weather conditions. Although randomly placed transects are preferable, logistic constraints often dictate the use of existing pathways, roadsides or management tracks – which requires the use of longer transects but is more practical in urban remnants.
(i) The transect method provides an accurate assessment of butterfly species richness in isolates provided that the level of sampling (proportion of area surveyed) is adequate, that sufficient surveys are conducted during the flight season to ensure high levels of detectability, and that surveys are conducted at appropriate times and during suitable weather conditions. Although randomly placed transects are preferable, logistic constraints often dictate the use of existing pathways, roadsides or management tracks – which requires the use of longer transects but is more practical in urban remnants.
(iii) Almost a century of fitting species–area curves has failed to produce agreement on which function is the best model of the relationship. Many of the proposed functions are identical, special cases of others or have arisen from transcription errors. Empirical comparison of these functions requires methods suited to the distribution of species number such as the generalized linear model, method of maximum likelihood and the information-theoretic approach, and proper attention to covariates and their interactions.
(iv) Site area and vegetation condition were the dominant determinants of the presence, abundance and total species richness of resident butterflies and day-active moths in 46 urban habitat fragments in south-west Western Australia. Larger sites with more high quality (undisturbed) vegetation favoured 16 of 20 native species and only one benefited from disturbance. A further nine species not sufficiently widespread or abundant to enable individual analysis were collectively more prevalent in larger sites. Resource quality and quantity dominated the patterns of site occupancy, and increased site connectivity did not favour any species – results consistent with habitat resources, not metapopulation effects, determining current distribution patterns. As expected, the presence of non-resident species was unaffected by site area. The total number of resident species at each site reflected the collective responses of the individual species: increasing with area and declining with vegetation disturbance. The effects of area and vegetation quality were not simply additive: disturbance had a far greater impact on small remnants. This interaction is inconsistent with the area per se hypothesis: in the absence of disturbance there was no evidence of a species–area effect.
This study is the first comprehensive, quantitative assessment of the distribution and ecology of butterflies and day-flying moths in Australian urban habitat fragments and provides a baseline against which future changes in species distributions may be measured. The results have important implications for the conservation of butterflies and day-flying moths in the region. Maintenance of vegetation quality is of paramount importance and is vital in smaller remnants. Large remnants, being less susceptible to local extinctions, will be essential for the persistence of many species. Many functions have been proposed to model the species–area relationship but empirical comparisons have been hindered by methodological problems – this study conducted a re-examination of the relationship and presents an appropriate framework to compare functions. This study is also one of few to demonstrate and quantify the importance of interactions in explaining patterns of species richness and should stimulate future research into the importance of these effects.

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Blakely, Tanya Jillaine. "Tree holes as habitat for aquatic and terrestrial invertebrates in mixed broadleaf-podocarp rainforest, New Zealand." Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1698.

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Little is known about the spatial distribution and abundance of tree holes in New Zealand’s native forests, or the invertebrate communities that they support. I found that tree holes were common on five endemic tree species, belonging to the families Fagaceae and Podocarpaceae in the mixed broadleaf-podocarp rainforest of Orikaka Ecological Area, Buller District, New Zealand. However, tree holes were not uniformly distributed throughout the forest, with more holes found on the three podocarp species, Prumnopitys ferruginea, P. taxifolia and Dacrycarpus dacrydioides, than on Nothofagus fusca or N. menziesii. Nevertheless, Nothofagus fusca had the largest holes of any of the tree species sampled and larger trees generally had larger holes. Large, hole-bearing Nothofagus fusca trees support a specialist hole-dwelling vertebrate fauna in New Zealand and worldwide, tree holes provide habitat for a range of invertebrate species. Using specially-designed emergence traps, I collected invertebrates emerging from naturally-occurring dry tree holes and compared this assemblage with invertebrates inhabiting leaf litter on the forest floor and those dispersing aerially throughout the study area. At the higher taxonomic resolution (i.e., Order or Class), community composition within the tree holes was highly variable, and there was no strong distinction between invertebrates from tree holes, leaf litter or Malaise traps. Moreover, although some beetle species emerging from tree holes were found exclusively in tree holes, most of these were represented by a single individual. Consequently, only minor differences in species composition were detected between beetle assemblages from tree holes, leaf-litter and those aerially dispersing throughout the forest. In contrast, the aquatic invertebrate assemblage within water-filled tree holes was highly distinctive from that in ground-based freshwater ecosystems, with only six aquatic taxa in common between all freshwater habitats. Using experimental water-filled tree-hole microcosms, I found that species richness and community composition within these microcosms were primarily driven by resource concentration, although habitat quality (i.e., water chemistry parameters) was also an important determinant of the identity and composition of colonising species. Overall, my study has shown that tree holes are common in the study area, and are likely to be more abundant in New Zealand’s indigenous forests than previously thought. Moreover, these generally small, discrete forest ecosystems support a diverse array of terrestrial invertebrates as well as a distinctive aquatic invertebrate community that is primarily structured by organic matter resource availability. These findings not only represent an important advance in our knowledge of New Zealand’s freshwater invertebrate biodiversity, but also highlight the need for further investigation into these unique forest canopy habitats which may well be at risk from deforestation and land use change.

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Bayliss, Julian Luke. "Use of GIS, geostatistics, and multilevel modelling for biodiversity action planning : the use of habitat association models for multi-species habitat conservation in the Upper Thames Tributaries Environmentally Sensitive Area." Thesis, Oxford Brookes University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251377.

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Gontier, Mikael. "Spatial prediction tools for biodiversity in environmental assessment." Doctoral thesis, Stockholm : Land and Water Resource Engineering (Mark- och vattenteknik), Kungliga Tekniskan högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4775.

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Arso, Civil Mònica. "Population ecology of bottlenose dolphins (Tursiops truncatus) off the east coast of Scotland." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6543.

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The population of bottlenose dolphins off the east coast of Scotland has been studied since the late 1980s, initially focused on the inner Moray Firth, where a Special Area of Conservation (SAC) was designated under the EU Habitats Directive. The population has since expanded its distributional range and currently ranges from the Moray Firth to the Firth of Forth. The main aims of this thesis were: (1) to estimate population parameters for this population using a 25 year individual recognition dataset, and (2) to increase knowledge of the distribution and abundance of dolphins in areas outside the SAC, especially to investigate areas of high use in St Andrews Bay. Apparent survival rate for adults and sub–adult dolphins was estimated at 0.946 (SE=0.005) accounting for temporary emigration caused by the population's range expansion. Sex-specific survival was estimated for males (0.951, SE=0.013) and females (0.956, SE=0.011) using multistate models to minimize bias caused by individuals of unknown sex. Using a newly developed approach, fecundity rate was estimated at 0.222 (95% CI=0.218-0.253) from an expected mean inter-birth interval of 4.49 yrs (95% CI=3.94-4.93). Total population size was estimated as ~200 individuals, after accounting for temporary emigration and for heterogeneity in capture probabilities. In St Andrews Bay, an area used regularly in summer by approximately half the estimated population, habitat use modelling identified the entrance to the Firth of Tay and waters around Montrose as high use areas for dolphins, whose presence was influenced by tidal current speed and direction. The results suggest that the conservation and management plan for this small and isolated population of bottlenose dolphins should be reviewed to adapt it to current knowledge, especially regarding the uncertainty around the potential impacts of offshore renewable energy developments off the east coast of Scotland.

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Sundblad, Göran. "Spatial Modelling of Coastal Fish – Methods and Applications." Doctoral thesis, Uppsala universitet, Limnologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132620.

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Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. Information on the distribution of resources and conservation values are also highly needed in marine management as coastal areas are increasingly influenced by human activities. In this thesis, large-scale field data is used to explore how strong environmental gradients found on multiple scales in the coastal areas of the Baltic Sea influence fish habitats. The underlying concepts are based in the field of species distribution modelling, whereby habitat maps can be produced using environmental layers in a geographic information system. Distribution modelling is further used to address both ecological and applied questions by examining effects of habitat limitation on fish population sizes and to evaluate management actions aimed at habitat conservation. I show that specific habitat requirements for fish species of both freshwater and marine origin can be described using environmental variables and that species-environment relationships can be used to predict the distribution of early life-stages of fish in the Baltic Sea archipelagos. Further, predicted habitat availability of a specific life-stage was directly related to adult population size of Eurasian perch Perca fluviatilis, signifying that the abundance of large predatory fish can be limited by specific recruitment habitats. Lastly, by predicting the distribution of an assemblage of coastal fish species and their associated habitats, an assessment of a network of marine protected areas was performed. Results revealed large gaps in the current network and identified areas suitable for future protection. By demonstrating how current habitat protection can be improved by including critical habitats for coastal fish population sizes this thesis points to the benefits of integrating nature conservation and fisheries management. Based on these findings I conclude that species distribution modelling provides a suitable analytical framework for assessing the habitat requirements of organisms. An increased understanding of habitat-population relationships and an ability to accurately map ecologically important features will be of great value for an ecosystem-based marine management.
Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 709

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Creegan, Helen P. "Modelling the effects of changing habitat characteristics and spatial pattern on woodland songbird distributions in West and Central Scotland." Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/48.

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This study investigated bird distributions in relation to local habitat and landscape pattern and the implications which habitat fragmentation may have for woodland birds. There were two sections to the research: an experimental study investigating bird gap crossing behaviour across distances of five to 120m; and an observational study modelling woodland bird distributions in relation to local habitat and landscape scale variables in two study areas (East Loch Lomond and the Central Scotland Forest). In the experimental study it was hypothesised that bird willingness to cross gaps will decrease with increasing gap distance even at home-range scales and that the rate of decline will vary interspecifically in relation to bird morphology. Song thrush mobbing calls played at woodland edges in the West of Scotland were used to attract birds across gaps and results were compared with the response along woodland edges. Data were obtained for four species: chaffinch, coal tit, robin and goldcrest. The decline in response with distance across gaps and along woodland edge was modelled for each species using generalized linear modelling. Maximum gap crossing distances ranged from 46m (goldcrest) to 150m (extrapolated value for the chaffinch). Goldcrests responded more readily through woodlands. There was no difference between woodland edge and gap response for the coal tit. Robins and chaffinches however responded more readily across gaps than through woodland. When different response indices were plotted against bird mass and wing area, results suggested that larger birds with bigger wings responded more readily across gaps than through woodland. It is suggested that this relates to differences in bird manoeuvrability within woodlands and ability to evade a predator in gaps. Fragmentation indices were calculated for an area of the Central Scotland Forest to show how willingness to cross different gap distances influences perception of how fragmented the woodlands are in a region. Results are discussed in the context of the creation of Forest Habitat Networks. The data for the observational section of the work was from bird point counts for 200 sample points at East Loch Lomond in 1998 and 2000 and 267 sample points in the Central Scotland Forest in 1999. In addition a time series of point count data was available for 30 sample points at East Loch Lomond. Additional data was gathered for ten sample points (1998) and two sample points (2000) at East Loch Lomond to investigate effects of observer, time and weather on count data. Generalized linear and generalized additive modelling was carried out on these additional data. Results indicated that biases due to the variation in time and weather conditions between counts existed in the pure count data but that these were eliminated by reducing data to presence and absence form for analysis. Species accumulation curves indicated that two counts per sample point were insufficient to determine species richness. However a sufficiently large proportion of the species was being detected consistently in two counts of ten minutes duration for it to be valid to model them in relation to habitat and landscape variables. Point count data for East Loch Lomond in 1998 (ELL98) and the Central Scotland Forest in 1999 (CSF99) for the wren, treecreeper, garden warbler, robin, blue tit, blackbird, willow warbler, coal tit, goldcrest, great tit, and song thrush were analysed using generalized additive modelling. In addition models were built for the blackcap (CSF99) and the siskin, redstart and wood warbler (ELL98). Where all relationships were identified as linear, models were rebuilt as GLMs. Models were evaluated using the Area Under the Curve (AUC) of Receiver Operating Characteristic (ROC) plots. AUC values ranged from 0.84-0.99 for ELL98 and from 0.76-0.93 for CSF99 indicating high predictive accuracy. Habitat variables accounted for the largest proportion of explained variation in all models and could be interpreted in terms of bird nesting and feeding behaviour. However additional variation was explained by landscape scale and fragmentation related (especially edge) variables. ELL98 models were used to predict bird distributions for Loch Lomond in 2000 (ELL00) and for the CSF99. Likewise the CSF99 models were used to predict distributions for ELL98 and ELL00. Predicted distributions had useful application in many cases within the ELL site between years. Fewer cases of useful application arose for predicting distributions between sites. Results are discussed in the context of the generality of bird environment relationships and reasons for low predictive accuracy when models are applied between sites and years. Models which had useful application for ELL00 were used to predict bird distributions for 2025 and 2050 at East Loch Lomond. Habitat and landscape changes were projected based on the proposed management for the site. Since woodland regeneration rates are difficult to predict, two scenarios were modelled, one assuming a modest amount of regeneration and one assuming no regeneration. Predictions derived from the ELL98 models showed broad-leaved species increasing in distribution while coniferous species declined. This was in keeping with the expected changes in the relative extent of broad-leaved and coniferous habitat. However, predictions from the CSF99 models were often less readily explicable. The value of the modelling approach is discussed and suggestions are made for further study to improve confidence in the predictions.

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Kimanzi, Johnstone Kithiki. "Mapping and modelling the population and habitat of the roan antelope (Hippotragus equinus langheldi) in Ruma National Park, Kenya." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1095.

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Wildlife-based tourism, which is Kenya’s second largest economic sector, is threatened by the risk of extinction of many wildlife species in the country. The endemic roan antelope (Hippotragus equinus langheldi) now only survives in Ruma National Park (RNP) where its population has been declining continuously since 1976. This thesis investigates the roan’s habitat use and selection, causes of population decline and population viability in RNP with the aim of recommending scientifically-based management interventions for population recovery and sustainable conservation. Roan movement patterns and habitat use were investigated using 4 home range estimation techniques. Habitat selection was studied at multi-spatial scales using compositional analysis, logistic regression, and information-theoretic (IT) and multi-model inference (MMI) techniques. Data for this study consisted of population estimates for roans and other grazers, Landsat images, soil maps, digital terrain data, rainfall records, snare distribution records, and roan ground tracking data. Identification of causes of population decline was carried out using both multivariate and univariate techniques. A generic population viability analysis (PVA) package was used to (i) estimate the likelihood of roan extinction under various management options; and (2) rank the management alternatives for roan population recovery. All 4 home range estimators are useful in characterizing different aspects of the roan home range, but overall the local convex hull method produced the most realistic home ranges. The three habitat selection methods yielded similar results but the IT techniques demonstrated superior qualities as they identified important habitat variables and produced the most accurate model predictions. MMI averaged models coupled with GIS data developed very informative habitat suitability and poaching risk maps. Analysis of habitat selection indicated different usage in seasons and spatial scales depending on water availability, habitat composition and burned status, and distribution of eco-geographical features. High adult mortality due to poaching with snares was identified as the main cause of roan population decline. Other important factors included habitat change and rainfall variability with its associated droughts and floods. PVA showed that under the current conditions, the roan population cannot persist more than 3 decades. Several anti-poaching and prioritized management interventions to curb poaching and promote population recovery are described.

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Tetley, Michael J. "The distr9bution, ecological niche modelling and habitat suitability mapping of the minke whale (balaenoptera acutorostrata) within the North Atlantic." Thesis, Bangor University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531046.

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Eastwood, Paul D. "Habitat modelling for the common sole (Solea Solea L.) in the Dover Strait and surrounding seas using regression quantiles." Thesis, University of Kent, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246581.

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Udumyan, Narine. "Surexploitation des ressources halieutiques : habitat, récifs artificiels et apprentissage." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM1082/document.

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Cette thèse a pour thème central l'étude de deux problèmes soulevés dans les pêcheries modernes, la dégradation des habitats et le manque d'informations, qui comptent parmi les causes les importantes de la surexploitation des ressources halieutiques. Les deux premiers chapitres sont consacrés à l'examen du problème de la dégradation des habitats marins liée notamment aux activités de pêche destructrices. Le modèle de Gordon-Schaefer est prolongé afin de tenir compte de l'impact négatif de la pêche sur les habitats. Les conséquences pour la gestion sont analysées et l'importance de la prise en compte des habitats dans le développement des programmes de gestion des ressources halieutiques est mise en évidence. Le modèle élaboré est ensuite utilisé pour évaluer les bénéfices économiques des récifs artificiels, un outil de gestion auquel font de plus en plus appel les gestionnaires des pêcheries artisanales pour répondre à la dégradation des habitats. Enfin, dans le troisième chapitre, le rôle de l'information pour une pêche durable est examiné lorsque la ressource est en accès libre. Si, dans les deux premiers chapitres, il est supposé que les informations complètes sont disponibles pour l'élaboration des recommandations de gestion, dans la dernière étude, la décision concernant l'exploitation des ressources halieutiques est prise dans un contexte où aucune information sur la ressource n'est accessible. Cette décision est prise individuellement par chaque pêcheur qui opère dans la pêcherie. En développant un modèle multi-agents, nous montrons l'impact de l'apprentissage des pêcheurs sur la dynamique globale du système halieutique
This thesis focuses on two main problems posed in contemporary fisheries: habitat degradation and lack of information. They count among the most important causes of the overexploitation of marine resources. The first two chapters aim at examining the habitat degradation that is linked to destructive fishing activities. The Gordon-Schaefer model is extended to take account of the negative impact of fishing on the habitats. The consequences for fisheries management are analyzed and the importance of taking into account habitats in the development of fisheries management programs is highlighted. Then the extended model is used to evaluate the economic benefits of artificial reefs, a management tool to which frequently resort the managers of small-scale fisheries to mitigate the effects of habitat degradation. Finally, in the third chapter the role of information for sustainable fisheries is examined under open access. If in the first two chapters it is assumed that there is complete information, in the last study this assumption is relaxed - no information on the resource is known. The decision concerning the exploitation of marine resources is made individually by each fisherman that operates in the fishery. By developing an agent-based model, we show the impact of individual learning on the global dynamics of the system

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Robinson, Timothy P. "Modelling the seasonal distribution of habitat suitability for armyworm population development in East Afirca using GIS and remote sensing techniques." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306322.

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Roger, Erin Biological Earth &amp Environmental Sciences Faculty of Science UNSW. "The persistence of common wombats in road impacted environments." Awarded by:University of New South Wales. Biological, Earth & Environmental Sciences, 2009. http://handle.unsw.edu.au/1959.4/44530.

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There is growing global concern over the influence of road development on the conservation of biodiversity and on the functioning of ecosystems. Published reviews in the field of road ecology have identified that most research has examined the effects of roads linearly and have advocated for research at landscape scales. Among the many effects roads have, one of the most significant is the loss of animal life resulting from collisions with vehicles. Despite this, little is known of what toll this has on animal populations and how these impacts vary with scale. This stems from the perception that impacts are localised and that animals killed are typically considered common, and therefore not of great conservation concern. This thesis challenges this notion by showing that the impacts of fatalities can affect populations at landscape extents and that commonness is not a barrier to localised extinction risk. To achieve this I focus on the common wombat; an example of a common species for which road impacts have never been previously examined. Chapter 1 provides an overview of the importance of scale in quantifying road impacts and the debate surrounding common species persistence in road environments. Chapter 2 assesses habitat use of wombats in a road environment at a local scale. Results suggest that wombats select for roadside habitat and as a result populations could be under threat. Chapter 3 is a predictive model of wombat road fatalities which demonstrates the importance of incorporating habitat use in predictive fatality modelling. Through use of a spatially explicit population viability analysis, Chapter 4 demonstrates that roads, in conjunction with other threats can affect the persistence of a common species at a local scale. Chapter 5 is a landscape extent assessment of wombat habitat use, finding that increased effort should be employed in evaluating how reserves confer resilience to species from the impacts of roads and that habitat quality can dictate road-based fatality rates. Chapter 6 summarises the research presented in the thesis and suggests direction for future work, particularly the importance of evaluating the interplay between susceptibility and abundance on species vulnerability in road environments.

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Holloway, Simon, and n/a. "Survey protocols for the stream-breeding frogs of Far East Gippsland : the application of habitat modelling and an assessment of techniques." University of Canberra. Resource, Environmental & Heritage Sciences, 1997. http://erl.canberra.edu.au./public/adt-AUC20060725.150009.

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This study developed a heirarchical approach to improve the efficiency and reliability of surveys for stream-breeding frogs in the montane forests of south-eastern Australia. Areas with suitable climate for some of these species were first determined by bioclimatic modelling. Landscape and habitat preferences were then determined for the four species commonly found in far East Gippsland, along with an assessment of survey techniques from which effective survey protocols were developed. The climate of localities at which five stream-breeding species had been previously found was modelled using BIOCLIM, and maps of the predicted potential distributions having similar climate were developed. Litoria phyllochroa was found to occur in coastal to alpine areas from Melbourne to Nowra, and potentially further inland, in areas with relatively low temperatures and low summer rainfall. Litoria lesueuri had a slightly larger known and predicted distribution, covering a wide range of values for the temperature and precipitation parameters. Both species had predicted areas inland from Melbourne and the Blue Mountains where they had never been recorded, probably largely due to land clearing. The rare Heleioporus australiacus had a slightly more northerly distribution, closer to the coast and adjacent ranges from Central Gippsland to just north of Sydney, with a generally warmer climate and large range of average annual precipitation values. Litoria citropa occupies an even narrower area along the coast, extending slightly further north again, with a climatic profile of few extremes but with relatively high rainfall particularly in summer. The rare Mixophyes balbus had a more northerly known and predicted narrow range along the NSW coast, just extending into Victoria and Queensland, characterised by the subtropical influence of higher summer rainfall. The southern extension into far East Gippsland appears to have an extreme sub-climate, and is hence considered highly susceptible to climate change. Future monitoring sites for these species can now be systematically chosen to include their full climatic range, so that any negative effects of climate change on amphibian populations may have a greater chance of detection. Four species were found commonly enough in the far East Gippsland study area for more detailed study - the three stream-breeding specialist species, L. phyllochroa, L citropa, and L. lesueuri, along with Crinia signifera which was not restricted to streams but commonly found along them. Three species, L. phyllochroa, L citropa and L. lesueuri, were not found at the few higher altitudes sites on the Errinundra Plateau, however they may have been restricted by habitat requirements other than altitude. Litoria phyllochroa was otherwise widespread, but preferred larger in-stream pools and backwaters for breeding with overhanging vegetation for perch and call sites. The other three species preferred stream reaches characterised by wide bedrock outcrops and associated wide break in the tree canopy, which may allow their preferred perch sites on rocky substrates to retain heat after sunset. Litoria lesueuri tadpoles were found in both unconnected and connected pools, and the common association of this species with bedrock outcrops may explain its range being largely restricted to granitic substratum where these outcrops mostly occurred. Litoria citropa preferred reaches with bedrock and boulder outcrops, although frogs used both rocky and vegetative substrates as perch sites, with tadpoles caught in both unconnected pools and backwaters. Crinia signifera tadpoles were mostly restricted to unconnected pools, with frogs generally only detected within or very close beside these. Habitat models varied in their predictive ability, from 67.5% for L. phyllochroa frogs to 92.7% for L. lesueuri tadpoles. Models developed from normally-distributed habitat variables by discriminant function analysis were generally more predictive than those from logistic regression analysis. The occurrence of frogs and tadpoles of L. phyllochroa, L. citropa and L. lesueuri can be predicted by the measurement of five habitat variables along a 50m reach: average width between the banks, average channel width, an average of the maximum depth of channel cross-sections along the reach, channel slope, and proportion of the stream length as pools. The occurrence of C. signifera along reaches can be predicted with the additional measurement of the proportion of the banks covered in ferns, the maximum cross-sectional channel depth along the reach, and the number of unconnected pools. Several different techniques for surveying frogs were compared for the four species commonly found along the streams. Probability of detection models were derived for each species for each technique, which allowed calculation of the statistical confidence of detecting a species that actually occurred at a site for any given number of surveys. For transect-based techniques, models were also developed which allowed determination of the minimum number of surveys required without detecting a species to be 95 percent statistically confident that the species did not occur there, for various transect lengths. This level of confidence can be obtained for the four common species by four surveys using the reliable night encounter technique along 500m stream transects, during the period from Ocotber to March, with air temperatures above 10°C. The application of habitat models to select favourable 50m reaches for survey also generally improved the detectability of each species. Timer-activated tape recorders, which automatically recorded the calls of frogs for many consecutive nights at a site, were very efficient at detecting all species except the quietcalling L. lesueuri. Night encounter surveys along stream transects detected all species from a reasonable effort, and dip-netting for tadpoles was also effective for most species. Active visual encounter surveys were less reliable, and day encounter surveys detected few frogs but provided some additional data when other activities were being performed along the streams. The findings of this study have important implications for future amphibian surveys and monitoring undertaken in East Gippsland and the south coast of New South Wales. If the standardised survey techniques recommended by this study are used in Environmental Impact Assessments, their results can be objectively assessed and defended. The use of habitat modelling and improvement in survey reliability can also be used more efficiently to find sites with populations suitable for monitoring. The likely amount of effort required by a long-term monitoring program can also be determined so as to largely overcome daily variations in the detection of each species.

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Dissertations / Theses on the topic 'Habitat modelling'

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