Rozprawy doktorskie: „Habitat suitability model”

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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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Kearns, Amy E. "Verifying Manitoba's 1994 draft barred owl habitat suitability index model". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ41660.pdf.

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Dine, James. "A habitat suitability model for Ricord's iguana in the Dominican Republic". Connect to resource online, 2009. http://hdl.handle.net/1805/1889.

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Thesis (M.S.)--Indiana University, 2009.
Title from screen (viewed on August 27, 2009). Department of Geography, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Jan Ramer, Aniruddha Banergee, Jeffery Wilson. Includes vita. Includes bibliographical references (leaves 47-52).

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Burroughs, Virginia. "An Assessment of Habitat Suitability for Pronghorn Populations of the Central Valley Region of California". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1142.

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Efforts to reintroduce and maintain populations of pronghorn (Antilocapra americana) to the California Central Valley, specifically the Carrizo Plain National Monument (CPNM) and the Mojave Desert (Antelope Valley) portion of Tejon Ranch, have largely been unsuccessful due to dwindling numbers of translocated animals. The objective of this study was to improve upon previous models for the CPNM using aerial survey data and then apply the model to the Tejon Ranch. Aerial survey data collected from 2000-2010 on the CPNM was used to establish “use” and “non-use” areas in the model. Model variables included vegetation type (forest, shrub, grassland, semi-desert scrub, crops, and bare areas), slope, and road density. Vegetation and road density variables were treated categorically and slope as a continuous variable. Kernel density estimation (KDE) was used to estimate utilization distributions and home ranges (Fieberg 2007). An 80% isopleth was used to define “used” and “unused” habitat areas within the study site. Binary logistic regression was used to detect correlations between habitat variables and habitat use by pronghorn. Results of the regression analysis indicated overall significance with a p-value of < 0.0001 (testing that all slopes = 0). Each habitat variable comparison was made after adjusting for the other variables (e.g., slope effects were evaluated after adjusting for road density and vegetation type) and was found to be significant. Each variable coefficient was then included in a predictive equation and entered into GIS to generate a map to predict where pronghorn would likely be observed. Similar layers were created for the Tejon Ranch and the predictive equation was run with the CPNM statistical analysis. Limited conclusions about habitat suitability on the CPNM or the Tejon Ranch can be made based on the habitat data available for this model. While slope, road density, and vegetation type are all significant habitat variables influencing pronghorn habitat use, further study is needed to understand the mechanisms driving these relationships. With additional data expansion of the current habitat suitability model would help to further define pronghorn habitat use, specifically the creation of a focused model of a particular season, life history period, or individual animal use to identify more detailed habitat use patterns.

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Gallien, Laure. "Comprendre et prédire l'expansion géographique des espèces végétales invasives dans les Alpes". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENV062/document.

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Les invasions biologiques, deuxième menace majeure de la biodiversité, pose d'important défis pour la conservation de la biodiversité, et la recherche en éco-évolution. Les espèces invasives ont en effet été étudiées depuis plus de 150 ans, mais nos capacités à prédire leurs présences aujourd'hui et dans le futur reste rudimentaire. Ce problème est principalement dû à la difficulté d'estimer à la fois les composantes biotiques et abiotiques de la niche des espèces invasives, ainsi que leur évolution dans le temps et l'espace. L'objectif de ma thèse a été de travailler sur ces défis en améliorant les méthodes d'estimation de niche, en enrichissant notre compréhension du rôle des interactions biotiques dans le processus d'invasion, et en étudiant en détail comment les processus évolutifs peuvent affecter la dynamique spatio-temporelle des niches. Plus précisément, (1) à l'aide d'une revue de la littérature, j'ai commencé par décrire les limites des différentes approches de modélisation utilisées pour prédire la distribution des espèces invasives. (2) Ensuite, j'ai proposé un cadre de modélisation permettant d'améliorer l'estimation des niches abiotiques régionales. (3) Puis, je me suis intéressée à la caractérisation des interactions biotiques, et aux méthodes communément utilisées pour identifier les patrons de compétition symétrique en écologie des communautés. J'ai également implémenté un modèle de simulation d'assemblage de communautés pour tester la performance de ces méthodes. (4) Ces premières études m'ont permis d'étudier à la fois les composantes biotiques et abiotiques des communautés de plantes envahies dans les Alpes. (5) Finalement, j'ai étudié l'évolution de la niche environnementale chez une espèce invasive des Alpes françaises Ambrosia artemisiifolia L, à travers une approche reliant niche-trait-génétique. Dans l'ensemble, les résultats de ces études montrent à quel point les différentes facettes de l'écologie et l'évolution en invasion sont fortement intriquées. De plus, ils soulignent la nécessité d'une modélisation intégrant les processus écologiques et évolutifs pour pouvoir comprendre la dynamique des invasions et proposer des outils de protection de la biodiversité efficaces
Biological invasions, the second major threat to biodiversity, pose significant challenges to conservation management and eco-evolutionary research. Even though invasion processes have been studied for more than 150 years, our capacity to predict their presence today and in the future is still rudimentary. This deficiency stems mainly from the difficulty involved in reliably assessing the ecological niche of an invader, i.e. those environmental and biotic conditions that allow the species to maintain viable populations. In particular, disentangling the abiotic and biotic components of the ecological niche and accounting for their changing over space and time due to evolutionary dynamics is difficult, albeit crucial for the quality of predictions. The main objective of my PhD has been to address these challenges by improving methodological approaches of niche estimation, advancing our understanding of the role of biotic interactions for invasion processes and studying in greater detail how evolution may affect spatio-temporal niche dynamics. More precisely, (1) with a comprehensive literature review, I started by describing the limits of the different modelling approaches usually applied to predict invasive species distributions. (2) Then, I provided a modelling framework for improving regional environmental niche estimations. (3) Thirdly, I focused on the identification of biotic interactions, and the methods commonly used to identify patterns of symmetric competition in ecological communities. I also implemented a simulation model of community assembly to test the efficiency of these methods. (4) In a fourth part, I studied invaded alpine plant communities and showed that characteristics of the biotic environment in these communities (e.g. symmetric vs. asymmetric competition) were good predictors of invaders' presence. (5) Finally, I provided a first example of a genetic-based, climatic niche expansion of the invasive weed Ambrosia artemisiifolia L. in the French Alps by combining information on its environmental niche, genetic structure and functional traits. Taken together, the results of these studies highlight how tightly the different facets of invasion ecology and evolution are interrelated and open the way to an integrated modelling approach that would advance both eco-evolutionary research on invasion dynamics and applied tools for biodiversity protection

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Thomasson, Victor. "Habitat Suitability Modeling for the Eastern Hog-nosed Snake, 'Heterodon platirhinos', in Ontario". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23322.

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With exploding human populations and landscapes that are changing, an increasing number of wildlife species are brought to the brink of extinction. In Canada, the eastern hog-nosed snake, 'Heterodon platirhinos', is found in a limited portion of southern Ontario. Designated as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), this reptile has been losing its habitat at an alarming rate. Due to the increase in development of southern Ontario, it is crucial to document what limits the snake’s habitat to direct conservation efforts better, for the long-term survival of this species. The goals of this study are: 1) to examine what environmental parameters are linked to the presence of the species at a landscape scale; 2) to predict where the snakes can be found in Ontario through GIS-based habitat suitability models (HSMs); and 3) to assess the role of biotic interactions in HSMs. Three models with high predictive power were employed: Maxent, Boosted Regression Trees (BRTs), and the Genetic Algorithm for Rule-set Production (GARP). Habitat suitability maps were constructed for the eastern hog-nosed snake for its entire Canadian distribution and models were validated with both threshold dependent and independent metrics. Maxent and BRT performed better than GARP and all models predict fewer areas of high suitability when landscape variables are used with current occurrences. Forest density and maximum temperature during the active season were the two variables that contributed the most to models predicting the current distribution of the species. Biotic variables increased the performance of models not by representing a limiting resource, but by representing the inequality of sampling and areas where forest remains. Although habitat suitability models rely on many assumptions, they remain useful in the fields of conservation and landscape management. In addition to help identify critical habitat, HSMs may be used as a tool to better manage land to allow for the survival of species at risk.

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Alizadeh, Shabani Afshin, i afshin alizadeh@rmit edu au. "Identifying bird species as biodiversity indicators for terrestrial ecosystem management". RMIT University. Mathematical and Geospatial Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20061116.161912.

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It is widely known that the world is losing biodiversity and primarily it is thought to be caused by anthropogenic activities. Many of these activities have been identified. However, we still lack a clear understanding of the causal relationships between human activities and the pressures they place on the environment and biodiversity. We need to know how ecosystems and individual species respond to changes in human activities and therefore how best to moderate our actions and reduce the rate of loss of biodiversity. One of the ways to detect these changes is to use indicators of ecosystem conditions. Indicators are statistics following changes in a particular factor usually over time. These indicators are used to summarise a complex set of data, and are seen as being representative of the wider situation in that field. So it can be assumed that if that particular factor is declining or improving, then the situation in general is also declining or improving. They are used to check the status and trends of biodiversity by both the public and policy makers. Indicators are also used to assess national performance and can be used to identify the actions required at the policy level. In this manner, they provide an important link between policy-makers and scientists collecting the data. The current thesis investigates the possibility of using bird species as indicators of biodiversity for better management of natural terrestrial ecosystems, by identifying their habitats according to various environmental factors. The study is established by drawing upon three main scientific areas: ecology, geographical information system (GIS), and statistical modelling. The Mornington Peninsula and Western Port Biosphere Reserve (MPWPBR) (Victoria, Australia) was chosen for the study area because of the combination of suburban and natural environments that made it optimum for this type of study. Once the study area was defined, the necessary data for the research were obtained from various sources. Birds Australia provided data on recorded observation of 271 bird species within the study area. Based on the nature of this study, seven species were selected for the study. The criteria for this selection are discussed in Chapter 3. Most literature state that the primary determinant for bird abundance is vegetation and land cover. Because of this, Ecological Vegetation Class (EVC) layer was used to determine which type(s) of vegetation have the greatest impact on habitat selection. Each species showed a relationship to a number of v vegetation types. These EVCs were combined to produce vegetation patches, and were considered as potentially suitable habitats of corresponding bird species. For each of the species, these habitat patches were analysed for the different aspects of patch characteristics (such as the level of patchiness, connectivity, size, shape, weighted distance between patches, etc.) by using the Landscape Context Tool (a GIS add-on). This process assisted the understanding of the importance of patch quality in habitat selection among different bird species by analysing the location of bird observation sites relative to habitat patches. In this way, the association between bird presence and the conditions of a habitat patch was identified by performing a discriminant function analysis. To investigate the probability of a species presence according to different environmental factors, a model of species distribution was created. Binary logistic regression was used to indicate the level of effect of each variable. The model was then successfully validated in the field. To define the indicators of environmental factors, it was essential to separate bird species based on their dependency on one or more of the studied variables. For this purpose, One-Way ANOVA was used. This analysis showed that some bird species can be considered as indicators of urban areas, while others could be good indicators of wellpreserved large forests. Finally, it must be mentioned that the type and quality of the datasets are crucial to this type of study, because some species have a higher degree of sensitivity to certain types of vegetation or land cover. Therefore, the vegetation data must be produced as detailed as possible. At the same time, the species data needs to be collected based on the presence and absence (versus presence-only) of the birds.

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Correa-Berger, Bryan P. "Developing a habitat suitability model for the spotted turtle using a hybrid-deductive approach /". Online version of thesis, 2007. http://hdl.handle.net/1850/4494.

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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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Uhmann, Tanys V. "The development of a habitat suitability index model for burrowing owls in southwestern Manitoba and southeastern Saskatchewan". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62861.pdf.

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Tonkovich, Michael Joseph. "Field evaluation of the northern bobwhite habitat suitability index model with implications for the conservation reserve program /". This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-162348/.

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Tonkovich, Michael J. "Field evaluation of the northern bobwhite habitat suitability index model with implications for the conservation reserve program". Diss., Virginia Tech, 1995. http://hdl.handle.net/10919/38183.

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Buck, Courtney E. "Habitat Suitability Index Model of the Florida Sandhill Crane (Grus canadensis pratensis) in West-Central Florida". Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7752.

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The Florida Sandhill Crane (Grus canadensis pratensis) is a state threatened endemic subspecies of the Sandhill Crane (Nesbitt & Tacha, 1997). With a population that was estimated at a maximum of 5,000 individuals in 2003 (Nesbitt & Hatchitt, 2008), it is imperative to identify potentially viable habitats, as Florida is rapidly developing. This research develops a Habitat Suitability Index model to determine unsuitable to optimally suitable habitat locations throughout west-central Florida. To do so, six suitability variables based on the crane’s life history were evaluated: Potential nesting area, immediate nesting area, wetland coverage, foraging area, brooding area, and road proximity. The results were compiled into a map, which showcased a gradient of habitat suitability within the Southwest Florida Water Management District boundary. Validation of this model included assessing the 2013-2017 stop data obtained from the North American Breeding Bird Survey for two routes in the project area. However, this data proved to be insufficient and unreliable, resulting in insignificance. The intention of this research was to prioritize those areas that are of optimal suitability to assist on conservation management of this threatened species. However, it highlighted the necessity for updated research, data, and population information for the Florida Sandhill Crane.

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Collier, Jessica J. "Creating a Spatially-Explicit Habitat Suitability Index Model for Lake Sturgeon (Acipenser fulvescens) in the Maumee River, Ohio". University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525350340081516.

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Smith, Richardt John. "Development of a habitat suitability model to determine the potential distribution of Klipspringer (Oreotragus Oreotragus subsp. Oreotragus) in Table Mountain National Park". Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2028.

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Thesis (MTech (Nature Conservation))--Cape Peninsula University of Technology, 2015.
The klipspringer (Oreotragus oreotragus subsp. oreotragus) population became extinct on the Cape Peninsula in 1930. Being re-introduced into Table Mountain National Park (TMNP) in 1999 it became one of the species of special conservation concern to monitor in the Park. Most klipspringer territories are known by Park management but the distribution of all potentially suitable habitats for this species in the Park is not known. The main aim of this study is to produce a distribution range map that is representative of all potentially suitable habitats for the klipspringer within TMNP, through the use of a species distribution modelling tool. Since only presence data were available for this study, a popular presence-only modelling tool namely maximum entropy (MaxEnt) was used. The use of MaxEnt in species distribution modelling has become popular as it has proven to provide robust predictions of a species’ geographic distribution. Klipspringer occurrence data and five environmental variables namely altitude, slope, aspect, vegetation, and distance to urban edge were used as model input. Occurrence data were sourced through existing databases and employing a stratified random sampling technique of dividing the Park into different habitat subtypes to survey the Park for more klipspringer occurrences. These habitat subtypes consisted of a variety of vegetation communities or vegetation types and altitudinal and slope ranges available in the Park. Grid size for all the raster layers used was 10x10 m. Spatial filtering of one point per 100 m² grid was used to eliminate clumping of points. Six models were run at different regularisation multiplier (RM) values namely 0.25, 0.5, default (1), 2, 4 and 7. To assist in better understanding of the spatial extent of the occurrence data and the areas inhabited by the klipspringer, home range analyses were carried out. This was done through kernel density estimation in the Geospatial Modelling Environment (GME). All six bandwidth parameters in GME namely smoothed cross validation (SCV), biased cross-validation (BCV), a second BCV algorithm, plug-in estimator, least squares cross validation and the likelihood cross validation (CVh) were tested. The smoothed cross validation and likelihood cross validation bandwidth algorithms provided the best visual output of klipspringer home ranges and territories. Home range sizes from the SCV output ranged from about 3 – 11 ha across the study area, and home range size for the CVh output ranged from 0.6 – 2.5 ha. The output from the CVh algorithm was interpreted as territories rather than home ranges, as it is based on a univariate kernel unlike, the SCV algorithm that produces rotated bivariate kernels. iv The default regularisation multiplier of 1 provided the best probability distribution output, whilst values lower than the default tended to underestimate the prediction and those values higher than the default were tending towards overestimations. Response curves for the default RM also gave the most ecologically meaningful responses of the klipspringer to each environmental variable. Model evaluation in the form of area under the receiver operating characteristic curve (ROC AUC) showed that all models performed well. Therefore, the choice of the “best” model was based on the ability to provide ecological interpretation, on the shape of the response curve and the probability distribution maps. Consequently, the default RM model was considered the best, with an AUC score of 0.903. Altitude and vegetation contributed the most to suitable habitat and therefore indicates that klipspringer in the Park do prefer high altitudinal areas with the right vegetation to feed on. Suitable altitudinal ranges are from 400 m.a.s.l. and higher and ericaceous fynbos is the most preferred vegetation community. Slope, aspect and distance to urban edge played a less important role in suitable klipspringer habitat. The probability map and an additional binary map produced at the 10 percentile training logistic presence threshold showed that suitable habitat for the klipspringer occurs in all three sections of the Park in different proportions. These maps can be used by Park management to prioritise conservation efforts and future re-introductions.
National Research Foundation

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Losee, Michele J. "Habitat Characteristics and Nesting Ecology of Golden Eagles in Arizona". Antioch University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1563035697672681.

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Meyer, Cynthia A. "Evaluating Habitat Vulnerability and Sustainability of Urban Seagrass Resources to Sea Level Rise". Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4918.

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The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource. Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive seagrass resource map (SGRM). The mesoscale field survey was designed and conducted in St. Joseph Sound (STJS) and Clearwater Harbor North (CLWN), Pinellas County, Florida from 2006-2010 to determine the seagrass species composition and spatial distribution for the resource. The seagrass species found in the study area consisted of Syringodium filiforme Kützing (Syringodium), Thalassia testudinum Banks ex König (Thalassia), and Halodule wrightii Ascherson (Halodule). These seagrass species occurred in monospecific and mixed beds in all combinations throughout the study area. Spatially, Thalassia was the dominant nearshore in STJS and Halodule in CLWN. Syringodium was most frequently found in STJS in the mid to deep depths. The SGRM was mapped from satellite remote sensing imagery with training information from the mesoscale field survey data. Landsat 5 Thematic Mapper (TM) and Earth Observing-1 Hyperion (HYP) were processed to map the seagrass resource in the study area in a nearshore shallow coastal area of Pinellas County, FL, USA. A maximum likelihood classification (MLC) was used to classify both TM and HYP imagery into three classes (seagrass estimated coverage) of the seagrass resource. The overall accuracy for the TM MLC map was 91% (kappa = 0.85) and the HYP was 95% (kappa = 0.92). Due to areas of cloud cover in the HYP image, it was necessary to composite the classification values from the TM MLC to accurately define these areas. The validation accuracy (n=72) of the composite seagrass resource map was 81% which was much more rigorous than the previous accuracy estimates. These results support the application of remote sensing methods to analyze the spatial extent of the seagrass resource. The development of a spatial habitat suitability model (HSM) for the seagrass resource provided a management tool to better understand the relationship between seagrass, water quality, and other environmental factors. The motivation to develop the spatial HSM was to provide a spatial modeling tool to simulate changes in the water quality environment and evaluate the potential impact on the seagrass resource. High resolution bathymetry and field survey water quality data were used to fit general additive models (GAM) to the STJS (Adjusted R2= 0.72, n=134) and CLWN (Adjusted R2= 0.75, n=138) seagrass resource. The final GAMs included water quality variables including salinity, chlorophyll-a concentration, total suspended solids, turbidity, and light. The only significant variable was the light metric in STJS (p-value= 0.001) and CLWN (p-value= 0.006). The light metric was the logarithmic light attenuation calculated from the water quality field survey transmittance (660nm) data and the high resolution bathymetry. The overall accuracy (OA) of the predictive GAM rasters was higher in CLWN (95%, kappa =0.88) than in STJS (82%, kappa = 0.40). The increased prediction error in STJS was spatially correlated with the areas of lower density seagrass along the deep edge of the bed. While there may be a plethora of factors contributing to the decreased density of the seagrass, this may indicate these seagrass were already living at the edge of the suitable habitat. Factors threatening the sustainability of the seagrass resource included those related to water quality and environmental changes. Knowledge of these relationships was essential to develop a predictive spatial HSM to simulate responses of the seagrass to changes in the water quality and the environment. Historically, environmental management strategies focused on water quality targets, but have not considered mitigation for climate change impacts, specifically sea level rise (SLR). This study utilized the HSM for the seagrass resource as a management tool to better understand the relationship between seagrass, water quality, and sea level rise scenarios. Based on SLR scenarios for 1ft-6ft (0.305m-1.83m) from 2010 to 2100, the potential seagrass habitat loss and gain was analyzed. From the current 60 km2 of seagrass habitat in St. Joseph Sound (STJS) and Clearwater Harbor North (CLWN), the predicted seagrass habitat loss based on the HSM which focused on light availability for photosynthesis ranged from 14 km2 (SLR 1ft) to 26 km2 (SLR 2ft) to the entire 60 km2 (SLR 6ft). The potential seagrass habitat gain based on the coastal flooding model (NOAA, 2012) ranged from 4 km2 (SLR 1ft) to 19 km2 (SLR 6ft). However, based on the spatial distribution of the seagrass and the proximity of the seagrass to the new habitat, the potential viable habitat based on the mean seagrass growth rates (horizontal rhizome elongation) only ranged from 2 km2 (SLR 1ft) to 9 km2 (SLR 6ft). An additional complexity to the gain of seagrass habitat was the effect of the anthropogenically altered shorelines, seawalls, which covered 47% of the shoreline. These seawalls potentially could impede the inundation of the seawater and the seagrass colonization of these areas by creating a vertical boundary for seagrass growth. The mitigation of the potential effects of SLR on the seagrass resource may require ecosystem level management. While management of water quality would continue to benefit the seagrass resource, additional management strategies would be necessary to mitigate for potential decrease in suitable seagrass habitat related to the effects of SLR. A discussion of potential management approaches suggested that the integration of coastal shoreline management strategies and seagrass resource management would be essential to insure the sustainability of the resource.

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González-Andrés, Cristina. "The role of marine offshore protected areas in protecting large pelagics. Practical case: Cocos Island National Park (Costa Rica)". Doctoral thesis, Universidad de Alicante, 2020. http://hdl.handle.net/10045/115291.

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Subalusky, Amanda Lee. "The role of seasonal wetlands in the ecology of the American alligator". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1640.

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Mainella, Alexa Marie. "Comparison of MaxEnt and boosted regression tree model performance in predicting the spatial distribution of threatened plant, Telephus spurge (Euphorbia telephioides)". Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1461880521.

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Williams, Alison Kay. "The influence of probability of detection when modeling species occurrence using GIS and survey data". Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/11129.

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I compared the performance of habitat models created from data of differing reliability. Because the reliability is dependent on the probability of detecting the species, I experimented to estimate detectability for a salamander species. Based on these estimates, I investigated the sensitivity of habitat models to varying detectability. Models were created using a database of amphibian and reptile observations at Fort A.P. Hill, Virginia, USA. Performance was compared among modeling methods, taxa, life histories, and sample sizes. Model performance was poor for all methods and species, except for the carpenter frog (Rana virgatipes). Discriminant function analysis and ecological niche factor analysis (ENFA) predicted presence better than logistic regression and Bayesian logistic regression models. Database collections of observations have limited value as input for modeling because of the lack of absence data. Without knowledge of detectability, it is unknown whether non-detection represents absence. To estimate detectability, I experimented with red-backed salamanders (Plethodon cinereus) using daytime, cover-object searches and nighttime, visual surveys. Salamanders were maintained in enclosures (n = 124) assigned to four treatments, daytime__low density, daytime__high density, nighttime__low density, and nighttime__high density. Multiple observations of each enclosure were made. Detectability was higher using daytime, cover-object searches (64%) than nighttime, visual surveys (20%). Detection was also higher in high-density (49%) versus low-density enclosures (35%). Because of variation in detectability, I tested model sensitivity to the probability of detection. A simulated distribution was created using functions relating habitat suitability to environmental variables from a landscape. Surveys were replicated by randomly selecting locations (n = 50, 100, 200, or 500) and determining whether the species was observed, based on the probability of detection (p = 40%, 60%, 80%, or 100%). Bayesian logistic regression and ENFA models were created for each sample. When detection was 80 __ 100%, Bayesian predictions were more correlated with the known suitability and identified presence more accurately than ENFA. Probability of detection was variable among sampling methods and effort. Models created from presence/absence data were sensitive to the probability of detection in the input data. This stresses the importance of quantifying detectability and using presence-only modeling methods when detectability is low. If planning for sampling as an input for suitability modeling, it is important to choose sampling methods to ensure that detection is 80% or higher.
Ph. D.

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McClafferty, Julie A. "An Assessment of the Biological and Socioeconomic Feasibility of Elk Restoration in Virginia". Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31295.

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The biological and socioeconomic feasibility of restoring elk (Cervus elaphus) to Virginia was assessed. Biological feasibility was determined by evaluating habitat suitability for elk while considering potential impacts of elk on existing fauna and flora in Virginia. Suitability was assessed by creating a habitat suitability index (HSI) model that measured the availability and accessibility of open foraging areas and forested cover areas, the availability of permanent water sources, and the degree of fragmentation by roads. Eight areas were identified as potential elk habitat: 1 in Southwest Virginia, 4 in the Shenandoah Mountains (Shenandoah, Highland, Big Meadows, Peaks of Otter), and 3 in the Southern Piedmont (Danville, Brookneal, Rehobeth). The highest potentials for supporting an elk herd were found in the Highland and Big Meadows study areas, medium biological feasibilities were found in the Southwest, Shenandoah, and Brookneal study areas, and low biological feasibilities were found in the Peaks of Otter, Danville, and Rehobeth study areas. A restored elk herd could negatively affect indigenous fauna and flora by changing the structure and diversity of existing forested ecosystems, but impacts can be minimized by maintaining elk populations at or below cultural carrying capacity. The introduction of diseases during restoration and possible transmission of those diseases from elk to humans, livestock, and other wildlife also are concerns, but these issues can be addressed by following a risk minimization protocol.

Socioeconomic feasibility was assessed with a statewide mail survey of Virginia residents, 4 regional stakeholder workshops, an analysis of economic costs and benefits associated with elk restoration, and an assessment of the risks of elk-human conflicts in each of the 8 study areas. Overall, most (61%) respondents agreed that elk restoration would be good for Virginia. However, the low response rate (30%) and low confidence among respondents (49%) in their knowledge about elk indicated that most residents do not have the interest and/or necessary information to form a definitive opinion. Residents believe that the greatest benefits of restoration would be the value-based and indirect ecological benefits, such as returning an extirpated species to its native range, whereas the greatest perceived costs were the economic impacts to property, crop depredation, and public safety hazards. In contrast, local stakeholder representatives identified economic returns from increased tourism due to the presence of elk and the creation of new recreational opportunities as the most anticipated benefits; important concerns were the potential for property damage by elk, the potential impacts on local ecosystems, and the costs of implementing and administering an elk restoration program and subsequent elk management. Proposed resolutions for these issues varied by region. Representatives from the Southwest and northern Shenandoah Mountain (Shenandoah and Big Meadows study site) Regions preferred not to restore elk, whereas those from the southern Shenandoah Mountain (Highland and Peaks of Otter study site) and the Southern Piedmont Regions preferred to start out small with a carefully controlled and monitored â experimentalâ population.

Economic benefits of elk restoration, as determined through analysis of data from other eastern states currently managing elk populations, are associated with tourism and the revenues brought to the community during elk hunting seasons, whereas economic costs are associated with crop damage, elk-vehicle collisions, and the administrative costs of managing an elk herd. Although the initial costs of transporting, releasing, and monitoring a founder population likely will exceed immediate benefits, once an elk population is established, benefits likely will exceed costs. However, an equitable distribution of costs and benefits must be devised so that the individuals who bear the costs are afforded a comparable or greater set of benefits.

Risk of landowner elk-conflicts was examined by comparing human population densities and growth rates, percent private versus public land, and agricultural trends across the 8 study areas. Highest risk for elk-human conflicts was identified in the Southern Piedmont Region and in the Shenandoah study site, risk was moderate in the Southwest, Big Meadows, and Peaks of Otter study sites, and risk in the Highland study site was low.

Overall, the Highland study site had the highest feasibility for elk restoration of all study areas examined; the Big Meadows and Southwest study sites both demonstrated moderate feasibility. Restoration in these areas is possible so long as management objectives remain flexible, plans are made in advance to address potential concerns, and the public is involved in the decision-making processes both before and after elk are released.
Master of Science

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Potter, Douglass W. "A GIS MODEL FOR APIARY SITE SELECTION BASED ON PROXIMITY TO NECTAR SOURCES UTILIZED IN VARIETAL HONEY PRODUCTION ON FORMER MINE SITES IN APPALACHIA". UKnowledge, 2019. https://uknowledge.uky.edu/forestry_etds/46.

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Beekeepers in Appalachia market varietal honeys derived from particular species of deciduous trees; however, finding places in a mountainous landscape to locate new beeyards is difficult. Site selection is hindered by the high up-front costs of negotiating access to remote areas with limited knowledge of the available forage. Remotely sensed data and species distribution modeling (SDM) of trees important to beekeepers could aid in locating apiary sites at the landscape scale. The objectives of this study are i) using publicly available forest inventory data, to model the spatial distribution of three native tree species that are important to honey producers in eastern Kentucky: American Basswood, Sourwood and Tulip Poplar, and to assess the accuracy of the models, ii) to incorporate a method for discounting the value of a nectar resource as a function of distance based on an energetic model of honeybee foraging, and iii) to provide an example by ranking potential apiary locations around the perimeter of a mine site in the study area based on their proximity to probable species habitat using a GIS model. Logistic regression models were trained using presence-absence records from 1,059 USFS Forest Inventory and Analysis (FIA) sub-plots distributed throughout a 9,000 km2 portion of the Kentucky River watershed. The models were evaluated by applying them to a separate dataset, 950 forest inventory sub-plots distributed over a 40.5 km2 research forest maintained by the University of Kentucky. Weights derived from an energic model of honeybee foraging were then applied to the probabilities of tree species occurrence predicted by the SDM. As an example, 24 potential apiary locations around the perimeter of a reclaimed mine site were selected and then ranked according to a site suitability index. Three tributary areas corresponding to different honeybee flight ranges were considered: 500m, 700m, and 1,200m. Results confirm that rankings are dependent on the foraging range considered, suggesting that the number of colonies at an apiary location would be an important factor to consider when choosing a site. However, the methodology makes assumptions that are only anecdotally supported, notably i) that colonies will forage preferentially at the target species when it is in bloom and, ii) that foragers will exhaust resources closest to the hive first, regardless of patch size. Additional study of how bees deplete the nectar resources surrounding an apiary is needed to verify the usefulness of SDM in site selection for varietal honey production.

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Jacobs, Teri A. "Putting the Wild Back into Wilderness: GIS Analysis of the Daniel Boone National Forest for Potential Red Wolf Reintroduction". University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1248796842.

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Hohler, Deborah Dorothea. "Evaluation of habitat suitability models for elk and cattle". Thesis, Connect to this title online, 2004. http://bibpurl.oclc.org/web/9208.

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Bravo, Vinaja Maria Guadalupe. "Evaluation of landscape level habitat characteristics of golden eagle habitat in Northwestern Mexico". Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/39683.

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Golden eagles (Aquila chrysaetos canadensis Linnaeus 1758) are declining in some areas throughout their Nearctic range (Sauer et al. 2011). This reduction is linked to changes in their habitat caused by human activities. Golden eagles inhabit an extensive range of environments (Watson 1997, Kochert et al. 2002). In the American Continent, the golden eagleâ s range encompasses Alaska, Canada, the United States and the Northern and Central portions of Mexico. Northern golden eagle populations migrate during winter to southern grounds, crossing international boundaries of Canada, the US and Mexico and therefore, their conservation is of trilateral concern. Golden eagles are protected by domestic laws in the three North American countries where they occur (FWCA 1997, BGEPA 1940, MBTA 1918, Lacey Act 1900, DOF 2002) and although the IUCN list the species as Least Concern, the A. c. canadensis subspecies has been protected by CITES since 1975 (Birdlife International 2012). While intensively studied in the United States, very little is known in Mexico about golden eagle ecology and their populations. As the national bird of Mexico, its conservation has been a priority for the Mexican government since its inclusion in the Endangered Species List in 1994 (SEDESOL 1994). Several threats jeopardize golden eagle populations throughout their range in North America: habitat alteration and fragmentation, electrocution, collisions with vehicles, collision with windmills and wires, poisoning from lead ingestion, drowning, shooting and trapping, and poaching for illegal wildlife trade. Mexican experts believe that a dramatic decline occurred over recent decades and that the remaining pairs have been restricted to remnant suitable habitat patches (SEMARNAP-INE 1999). Long-term survival of golden eagles largely depends on the effectiveness of current conservation efforts of habitat at a landscape level. Successful conservation and management requires accurate information on ecology of the species upon which decisions can be based. This study investigated habitat characteristics of the areas occupied by golden eagles and developed strategies for habitat management and protection to improve golden eagle viability in Chihuahua State. I surveyed a portion of Chihuahuan Desert Ecoregion in Mexico to locate golden eagle territories during 2009 and 2010. I located 30 golden eagle nesting territories and found similar composition of cover type, vegetation structure and prey indices between the territory cores and their buffer zones. Distance to most anthropogenic disturbance sources was similar between golden eagle sites and random areas (n=60). Grassland was the most common cover type, occurring in 100% of the nesting territories, and comprising 58% of the territoriesâ area, suggesting a disproportionate use of this cover type compared to its overall availability (25% of the state area). I used landscape attributes such as topographic characteristics and human disturbances to model the probability of occurrence of golden eagles across the landscape. I used logistic regression to model the occurrence of golden eagles at two different landscape scales and selected the best model at a home range scale based on AIC values to develop a predictive map of golden eagle distribution in Chihuahua, Mexico. I found that at a home range scale, golden eaglesâ occurrence was positively related to open areas and terrain ruggedness and negatively to human settlements, while at a larger scale it was positively related to open areas and negatively related to forested areas. The results confirm that golden eagles are dependent on grasslands and rugged terrain. I developed predictive maps of golden eagle occurrence using a logistic regression and a Mahalanobis distance approach using the variables from the model chosen to compare the performance and output with logistic regression modeling. I analyzed the Mexican National Plan for Golden Eagle Recovery (PACE - Ã guila Real) and proposed a conservation strategy oriented to protect golden eagle populations and their habitat in Chihuahua, Mexico. This strategy integrates ecologic knowledge developed in the first two chapters and incorporates social participation of all stakeholders. The strategy recognizes the potential limitations of conservation implementation programs in Mexico and explores the potential opportunities to protect golden eagles populations and their habitat.
Ph. D.

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27

Pereira, Jose Miguel Oliveira Cardoso. "A spatial approach to statistical habitat suitability modeling: The Mt. Graham red squirrel case study". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184821.

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Multivariate statistical techniques were applied to the development of habitat suitability models for the Mt. Graham red squirrel, an endangered species. A digital map data base and a geographic information system (GIS) were used to support the analysis and provide input for two logistic multiple regression models. Squirrel presence/absence is the dichotomous dependent variable whose probability the models pretend to predict. Independent variables are a set of environmental factors in the first model, and locational variables in the second case, where a logistic trend surface was developed. Bayesian statistics were then used to integrate the models into a combined model. Potential habitat losses resulting from the development of an astronomical observatory were assessed using the environmental model and are found to represent about 3% of currently available habitat.

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Ciocheti, Giordano. "Spatial and temporal influences of road duplication on wildlife road kill using habitat suitability models". Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/1835.

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Financiadora de Estudos e Projetos
Urban growth and population growth led to the construction of a gigantic road network around the world. This network is responsible for several impacts on fauna, flora and the environment, such as road kill, isolation of populations, facilitating the establishment of invasive species, river siltation, among others. However, although road ecology has advanced recently, there are still many gaps on how roads affect fauna, as little is known about how effects of changing the structure of highways can modify animal-vehicle collisions. This study aims to evaluate some of the impacts of roads on species of medium and large mammals in fragmented and naturally heterogeneous landscapes. Using a functional group approach based on animal sensitivity to disturbance and displacement capacity, I set out to answer three questions, one in each chapter: 1) the contribution of various landscape indices to predict wildlife road kill; 2) highway duplication and the implementation of wildlife crossing structures alter animal road kill; 3) duplication of roads change the way fauna road kill is correlated with the landscape metrics. To answer the first and third questions, we have developed innovative methods combining road kill data with a multi-scale approach with landscape metrics involving quantity and distance of various landscape elements, such as natural vegetation, cerrado, water, forestry and sugar cane. This method proposed was derived from habitat suitability model, and proved very promising for estimating the probability of animal road kill. Each functional group of species responded differently to landscape elements. Distance and amount of vegetation has been more important to estimate road kill probability of more sensitive mammals, but the amount of sugar cane also contributed to these results. The proposed method is highly replicable and can be easily applied in other regions with other taxa. The second question was addressed in an analytical way, with a conventional hypothesis testing approach. We found that, in general, there was no significant difference between road kill before and after road duplication. However, when considering the functional groups, and even species, some changes were significant for both increasing and reducing road kill. We also found that the proximity of wildlife crossing structures to road kill records did not reduce the frequency of animal-vehicle collision, indicating that such mitigation measures may not have been appropriate to reduce animal road mortality. Finally, in the third chapter we have proposed a new approach to estimate the changes in animal road kill probability before and after duplication of highways. In this chapter we recorded an increase in the probability of road kill after duplication for generalist species with high mobility. The methods proposed here are easy to implement in several actions related to roads, both for seeking their structural improvement and for making them more sustainable for biodiversity.
O crescimento urbano e o aumento populacional levaram a construção de uma gigantesca malha rodoviária ao redor do mundo. Essa malha é responsável por diversos impactos causados sobre a fauna, meio físico e flora, tais como: atropelamentos, isolamento de populações, facilitação no estabelecimento de espécies invasoras, assoreamento de rios, entre outros. Entretanto, embora a ecologia de estradas tenha avançado recentemente, ainda existem muitas lacunas sobre como elas afetam a fauna, da mesma forma que pouco se sabe sobre como os efeitos da mudança na estrutura das rodovias podem modificar o atropelamento de animais. Este estudo tem como objetivo avaliar alguns dos impactos das rodovias sobre espécies de mamíferos de médio e grande porte em paisagens fragmentadas e naturalmente heterogêneas. Utilizando uma abordagem de grupos funcionais baseados na sensibilidade à perturbação e na capacidade de deslocamento, me propus a responder três perguntas, sendo cada uma um capítulo: 1) qual a contribuição de diversos índices de paisagem para prever o atropelamento de fauna; 2) a duplicação das rodovias e a implementação de passagens de fauna alteram a taxa de atropelamentos dos animais; 3) a duplicação das rodovias altera a maneira que os atropelamentos de fauna são correlacionados com as métricas da paisagem. Para responder a primeira e terceira perguntas, desenvolvemos métodos inovadores combinando aos dados de atropelamentos, uma abordagem multi-escala de métricas da paisagem envolvendo quantidade e distância de diversos elementos da paisagem, como vegetação natural, cerrado, água, silvicultura e cana-de-açúcar. O método proposto no primeiro capítulo, derivado do modelo de adequabilidade de habitat, se mostrou bastante promissor para estimar a probabilidade de atropelamentos. Cada grupo funcional de espécies respondeu de forma diferente aos elementos da paisagem. Distância e quantidade de vegetação foram mais importantes para prever o atropelamento de mamíferos mais sensíveis, mas quantidade de cana de açúcar também contribuiu para os resultados. O método proposto apresenta alta replicabilidade e pode ser utilizado facilmente em outras regiões e para outros táxons. A segunda pergunta foi abordada de forma mais analítica, com uma abordagem de teste de hipótese convencional. Verificamos que, de modo geral, não houve diferença significativa entre os atropelamentos antes e depois da duplicação da estrada. Entretanto, ao se considerar os grupos funcionais, e mesmo as espécies, algumas alterações foram significativas tanto para o aumento e redução de atropelamentos, conforme o foco da análise. Ainda neste capítulo verificamos que a proximidade das passagens de fauna aos atropelamentos não reduziu a taxa de atropelamento, indicando que tais medidas de mitigação podem não estar sendo apropriadas para reduzir a mortalidade por atropelamentos. Por fim, no terceiro capítulo propusemos uma nova abordagem para estimar as mudanças dos atropelamentos antes e depois da duplicação das rodovias. Neste capítulo registramos um aumento na probabilidade de atropelamento de espécies depois da duplicação para espécies generalistas e com maior mobilidade. O uso dos métodos propostos neste trabalho são de fácil implementação em diversas ações relacionadas a estradas, tanto visando sua melhoria estrutural quanto para torná-las mais sustentáveis para a biodiversidade.

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Reid, Caroline. "Habitat suitability and behaviour of springbok (Antidorcas marsupialis) at Augrabies Falls National Park, South Africa". Thesis, University of Port Elizabeth, 2005. http://hdl.handle.net/10948/362.

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Habitat selection may be considered a behavioural consequence of an individual actively selecting where it lives or passively persisting in a certain habitat. There are a variety of approaches to assessing habitat selection, including relating densities to predefined habitats and the characteristics of these habitats, measuring the behaviour of animals within predefined habitats in order to assess the relative benefits to the animal and comparing these between habitats, and using optimality theory to allow the animal to provide measures of its preference for particular habitats or patches. Each approach provides different perspectives on an animal’s choice and use of habitat, with some approaches working more effectively with certain species or habitats than others. There have, however, been no attempts to apply all these approaches to a single species at a single site. The objective of this study was therefore to apply the three above-mentioned approaches to assess habitat use and quality to a single species, the springbok (Antidorcas marsupialis) at the Augrabies Falls National Park (AFNP), on the northern bank of the Orange River, in order to provide the basis for further work on comparing and integrating these approaches. The relative abundance of springbok in Augrabies Falls National park was used to develop a habitat suitability model for the park, and thus determine the habitat variables that influenced habitat suitability. Isodar analysis revealed information on the mechanisms underlying habitat preference. Behavioural models were developed to improve our understanding of how springbok behaviour changes in relation to the habitat, and incorporated the variables identified in the habitat suitability model. The different spatial and temporal scales influencing springbok habitat selection were determined using optimal foraging theory and giving-up densities. Springbok preferred open habitats providing high food quality. Springbok behaviour was related to the foraging and predation risk characteristics of the habitat, and springbok varied their temporal and spatial utilisation so as to minimise their risk of predation and maximise their food intake. The habitat suitability model, behaviour models and giving-up densities were compared for ease of use and applicability. Using giving-up densities to reveal habitat suitability had greater applicability and was both efficient and objective.

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Aletrari, Elina. "Beyond 2010 : use of habitat suitability models in the re-assessment of the 2010 Biodiversity Target for plant species". Thesis, King's College London (University of London), 2016. http://kclpure.kcl.ac.uk/portal/en/theses/beyond-2010(a77e5ffa-8c5e-413d-9c9b-c4bd1e4a9eb1).html.

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Human activities are placing unprecedented pressure on natural ecosystems, threatening to push many species into extinction. In response to this, a call for a reduction in the current rate of biodiversity loss by 2010 was made and global biodiversity indicators were adopted to monitor progress. Perhaps the best known of these are the Red List Indices, which are based on temporal changes in extinction risk of species assessed for the International Union for Conservation of Nature (IUCN) Red List. In the case of plants, conservation assessments for globally-representative samples of species have been carried out mainly utilising comprehensive worldwide herbarium resources, and have shown that more than 1 in 5 plant species is threatened with extinction under IUCN Red List Criteria. The aim of this thesis was to provide the scientific bases for an automated procedure to re-assess plant species pan-tropically on a 5-year time frame in order to calculate the change in the IUCN Sampled Red List Index (SRLI) for Plants as a measure of global trends in plants extinction risk. This study has focused first on improving the method used for calculating species ranges using the available IUCN SRLI for Plants data and to develop a new measure of species range, the Extent of Suitable Habitat (ESH). The results show that this new calculation method is effective at reflecting a closer reality of plant distributions on the ground, and that such a simple method can be used to predict the current distribution of species globally. The species ESHs were then assessed through time against the degree of human impact using data from a global monitoring system for deforestation and from a future land use change scenario applied by the Co$ting Nature tool. On the basis that land cover change can be used as a proxy for local extinction risk and that a species’ ESH can be re-calculated to factor in the impact of land cover change (habitat loss), this thesis showed that a species’ ESH could be used for re-assessing the conservation status of plant species under IUCN Criterion B sub-criterion b(iii). This way, more dynamic, comparable and spatially-detailed Red List Index updates could be provided. To test the ESH range calculation this method was also compared with a widely accepted species distribution modelling approach and validated using new species occurrence points. Additionally, ESH derived species richness maps were produced for conservation prioritisation, validated using fieldwork data from previous studies and compared with existing species richness maps for plants.

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Dornelles, Sidnei da Silva. "Impactos da duplicação de rodovias : variação da mortalidade de fauna na BR 101 Sul". Universidade Federal de São Carlos, 2015. https://repositorio.ufscar.br/handle/ufscar/7129.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Roadkill and isolation of populations due to the barrier effect can be considered the main direct impacts of roads on wildlife. Mammals by behavioral, size and charisma features are one of the groups of vertebrates that require mitigation for mortality, as they are also among the most seriously injured on roads. An important approach to effectively mitigate roadkill on highways is to locate the points where roadkill are concentrated. The objective of this study was to evaluate the variation in mortality of mammals due to the duplication of the BR 101 highway south. In addition to the K Ripley aggregation analysis, were generated habitat suitability models (MAH) to identify favorable locations roadkill species, using the model functional groups for prediction of highway stretches with more chances to roadkill. It was recorded 21 taxa of mammals get hit, being the most abundant gender Didelphis (n = 721), followed by Cerdocyon thous (n = 108). The abundance of carcasses decreases between before and after the duplication (F 18.04 p = <0.001). Hotspots were not overlapped between the periods analyzed, indicating that some explanatory factor has changed over the work. Observing the variables that contributed most to the models for each functional group, we noted that there were differences in the most influential variables for each functional group in different periods. Of the nine generated models, we note that six variables contributed more than 20% in different models. There were differences between the periods before, during and after the duplication of the variables that contributed most or contribution value in functional groups. These differences may reflect the change in the distribution of roadkill among highway doubling periods. Both approaches demonstrated that there have been changes in the magnitude and distribution of roadkill in the period prior to the period after duplication. So a highway with two paviments differ from a highway with four paviments about how the mammals react in terms of movement and relationship to landscape.
A morte por atropelamentos e o isolamento de populações devido ao efeito de barreira podem ser considerados os principais impactos diretos das rodovias sobre a fauna silvestre. Os mamíferos pelas características comportamentais, tamanho e carisma são um dos grupos de vertebrados que necessitam mitigações para a mortalidade, visto que também estão entre os que mais morrem em rodovias. Uma abordagem importante para mitigar efetivamente os atropelamentos em rodovias é localizar os pontos onde os atropelamentos estão concentrados. O objetivo deste trabalho foi avaliar a variação da mortalidade de mamíferos em função da duplicação da rodovia BR 101 sul. Além da análise de agregação de K de Ripley, foram gerados modelos de adequabilidade de habitat (MAH) para identificar locais favoráveis a atropelamentos de espécies, usando no modelo grupos funcionais para a predição de trechos da rodovia com mais chances de atropelamento. Registrou-se 21 taxóns de mamíferos atropelados, sendo o mais abundante o gênero Didelphis (n=721), seguido de Cerdocyon thous (n=108). A abundância de carcaças diminui entre o antes e o depois da duplicação (F=18,04; p<0,001). Os hotspots não foram sobrepostos entre os períodos analisados, indicando que algum fator explicativo mudou ao longo da obra. Observando as variáveis que mais contribuíram com os modelos para cada grupo funcional, notamos que houve diferença nas variáveis mais influentes para cada grupo funcional nos diferentes períodos. Dos nove modelos gerados, notamos que seis variáveis contribuíram em mais de 20% em diferentes modelos. Houve diferença entre os períodos de antes, durante e depois da duplicação das variáveis que mais contribuíram ou do valor de contribuição nos grupos funcionais. Estas diferenças podem ser reflexo da mudança na distribuição dos atropelamentos entre os períodos da duplicação da rodovia. As duas abordagens demonstraram que houveram mudanças na magnitude e distribuição dos atropelamentos no período antes em relação ao período após a duplicação. Portanto uma rodovia com dois pavimentos funciona diferente de uma rodovia de quatro pavimentos em relação a como a mastofauna reage em termos de movimentação e relação com paisagem.

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Adamatti, Daniela Santini. "Contribuições da incorporação de movimentação à modelagem ecológica da distribuição espacial de grupos funcionais de peixes em lago raso subtropical". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/147043.

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A distribuição espacial dos peixes em ecossistemas aquáticos é dependente de diversos fatores físicos, químicos e biológicos. Os peixes jovens e adultos podem direcionar seu movimento seguindo condições favoráveis no que concerne às condições ambientais e de biomassa de presas e predadores. Dentro desse contexto, o presente trabalho visou analisar as contribuições da incorporação da movimentação à modelagem ecológica baseada em processos, quando estimada a distribuição espacial da biomassa de grupos funcionais de peixes em lago raso subtropical. O movimento é representado através do efeito combinado entre os movimentos passivo, em função da hidrodinâmica da lagoa, e comportamental, baseado na capacidade dos peixes de buscar ambiente mais adequado. A cada intervalo de tempo, a velocidade e a direção da corrente, calculadas no módulo hidrodinâmico do modelo IPH-ECO, são utilizadas juntamente com a velocidade e direção obtidos para o movimento comportamental de cada grupo funcional de peixes, para atualizar a biomassa íctica. O movimento comportamental é determinado através da utilização de um índice de adequabilidade do habitat (HSI), considerando as respostas funcionais a fatores tais como biomassa de presas, biomassa de predadores, luz, temperatura e oxigênio dissolvido. O modelo sem a rotina de movimentação dos peixes resultou na estimativa de biomassas homogêneas de todos os grupos funcionais ao longo da lagoa. Com a incorporação da movimentação observaram-se diferenças significativas na dinâmicas das biomassas dos grupos funcionais de peixes tanto entre regiões geográficas quando entre regiões biológicas da lagoa. As biomassas de omnívoros e planctívoros adultos apresentaram forte relação com as biomassas de alimento, em especial com os zoobentos. A biomassa de piscívoros, além da biomassa de alimento, teve dependência de fatores físicos, tais como o coeficiente de atenuação da luz e temperatura. O modelo com movimentação beneficia o modelo ecológico ao representar a possibilidade dos peixes de escolher o habitat, no entanto, adiciona complexidade em função da inserção de parâmetros relacionados às respostas funcionais e aos pesos de cada resposta na formação do índice. Os movimentos comportamental e passivo podem ter importâncias relativas diferentes na definição da movimentação das biomassas dos grupos funcionais de peixes. O equacionamento e os parâmetros existentes no módulo de peixes no modelo IPH-ECO podem não estar representando de forma suficientemente adequada as comunidades de peixes de ecossistemas subtropicais.
The spatial distribution of fish in aquatic ecosystems is dependent on various physical, chemical and biological factors. Unlike early life stages, young and adult fish can direct their movement following favorable environmental and biomass of prey and predators conditions. This study aimed to analyze the contribution of fish movement incorporation in a process-based ecological modeling, when estimating the spatial distribution of fish functional groups biomass in a subtropical shallow lake. Fish movement is represented by the combined effect of passive movement, due to lake hydrodynamics, and behavioral movement, based on the ability of fish to seek more suitable environments. At each time step, the flow speed and direction estimated on IPH-ECO’s hydrodynamic module are used along with the speed and direction estimated for behavioral movement to update each fish’s functional group biomass position. The behavioral movement is determined using a habitat suitability index (HSI) considering the functional responses to factors such as prey and predator biomass, light, temperature and dissolved oxygen. Process-based modeling, without fish movement, resulted in homogeneous biomass estimatives along the lake when analizing all functional groups. Significant differences in fish biomass between geographical regions as well as between biological regions were observed when movement was incorporated. There is a strong relationship between adult omnivorous and planktivorous distribution and food biomass. Besides food biomass, piscivorous distribution did show dependence on physical factors such as the extinction coefficient of light and temperature. The opportunity of moving improves fish dynamics representation. Nonetheless, movement adds complexity to ecological modeling since there is the inclusion of parameters related to functional responses and the need of defining each ones weight when calculating the index. Behavioral and passive movements may have distinct relative importance to the biomass movement definition. Existing equations and parameters used to describe fish processes in the model might not be representing properly fish communities from subtropical ecosystems.

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Voogt, Nina Margaret. "Dietary aspects of establishing a mainland-based colony of the endangered African Penguin (Spheniscus demersus) in St Francis Bay, South Africa". Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1013115.

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Cape St Francis, Eastern Cape, has been identified as one of four potential sites for establishing a mainland-based African penguin (Spheniscus demersus) colony. This thesis comprises three main components: a verification of a preparation method for stable isotope samples from penguin feathers; a dietary analysis of the penguins on Bird Island, Algoa Bay, though stable isotope analysis of whole blood and feathers (2012 and 2013); and an estimation of available fish surplus that could potentially support a colony of penguins at Cape St Francis. Each component contributes towards the next, all building towards answering the main research question: Will there be enough food around St Francis Bay to support a colony of penguins and sustain the already established fisheries industry within the bay? Stable isotope analysis of whole blood and feathers from breeding adults and whole blood from juveniles provided insight into the variability of African penguins’ diets at different stages in their life history. Stable isotope mixing models indicated that the predicted proportions that each prey species could potentially contribute to diet conflicted with published stomach sample data. This might arise from inaccurate trophic enrichment factors used in the model, or from systematic biases in the published stomach sampling techniques, or both. Dietary sexual dimorphism was not demonstrated by the isotope signatures of breeding penguins. Based on official catch data, the fisheries activity on the south coast, and especially around the potential colony site at St Francis, is much lower than around the west coast’s penguin colonies. The model provided a first-order estimate for fish supply around the potential colony site at St Francis both at a large coastal scale and a local small scale. At both scales the estimate indicated an ample availability of fish at current fishing levels. The model in Chapter 4 can also be applied to refining the assessments of other potential colony sites on the south coast. In conclusion, the south coast is a promising area for a new colony of penguins in terms of food availability. There is relatively low fishing activity in the area and, as suggested by the large-scale model in Chapter 4, an ample fish resource. The final chapter briefly discusses factors that need to be considered before attempting to establish a mainland-based colony of African penguins.

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Syu, Jia-Wen, i 許嘉文. "Study on the Habitat Suitability of River Cross Section via Physical Habitat Simulation Model". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/25618152309842485614.

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碩士
義守大學
土木與生態工程學系
104
Due to the effect of climate change and uneven rainfall, main issues of river management focused on the flood control and water resources distribution. There are some weirs or dams built across the river bank without any consideration on the aqua-habitat properties that affected by various factors, such as velocity, depth or river bed materials. Ecological engineering and river ecology conservation became the hot study topics since 2000. In order to meet the requirement of aqua-habitat, “base flow” or “ecological base flow” is proposed as the guidelines during river management or water resources planning. One of the distinguished studies on river habitat conservation or restoration, weighted usable area (WUA) concept, was initiated by USGS. WUA considers the combination of velocity, depth, bed-materials and water temperature to simulate suitable area for the specific aqua-species in stream. Case study used in this paper is the reaches along Qishan River. Section properties (sectional profile, velocity, and discharge) from Bin-chiao to Chia-sian-chiao were collected. The suitable curve of red-trout and rainbow-trout were obtained from previous research report of Qishan River. Physical Habitat Simulation model (PHABSIM) developed by USGS is used in this paper to calculate the WUA under different flow rate and modification of cross section by groundsill works. Discharges from 30cms to 60cms are assumed as flow conditions, and grand sill raised river bed around 50cm~100cm are aligned as the river bed modification case. Results of the simulation show the WUA increased gradually by the increasing river flow. WUA is decreased due to groundsill at low flow, but increased rapidly at high flow. Since groundsill thwarts the river flow at high flow that makes more suitable zone for aqua-habitat. When the river flow depletes, some of habitat are replaced by concrete groundsill, and suitable area decreased.

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Dine, James. "A Habitat Suitability Model for Ricord’s Iguana in the Dominican Republic". Thesis, 2009. http://hdl.handle.net/1805/1889.

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Indiana University-Purdue University Indianapolis (IUPUI)
The West Indian iguanas of the genus Cyclura are the most endangered group of lizards in the world (Burton & Bloxam, 2002). The Ricord’s iguana, Cyclura ricordii, is listed as critically endangered by the International Union for Conservation of Nature (IUCN) (Ramer, 2004). This species is endemic to the island of Hispaniola (Figure 1), and can only be found in limited geographic areas (Burton & Bloxam, 2002). The range of this species is estimated to be only 60% of historical levels, with most areas being affected by some level of disturbance (Ottenwalder, 1996). The most recent population estimation is between 2,000 and 4,000 individuals (Burton & Bloxam, 2002). Information on potentially suitable habitat can help the conservation efforts for Ricord’s iguana. However, intensive ground surveys are not always feasible or cost effective, and cannot easily provide continuous coverage over a large area. This paper presents results from a pilot study that evaluated variables extracted from satellite imagery and digitally mapped data layers to map the probability of suitable Ricord’s iguana habitat. Bayesian methods were used to determine the probability that each pixel in the study areas is suitable habitat for Ricord’s iguanas by evaluating relevant environmental attributes. This model predicts the probability that an area is suitable habitat based on the values of the environmental attributes including landscape biophysical characteristics, terrain data, and bioclimatic variables.

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Yu, Yi-Yin, i 尤薏茵. "Habitat suitability empirical model ofalbacore tuna in the South Atlantic Ocean". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/sef4zs.

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碩士
國立臺灣海洋大學
環境生物與漁業科學學系
107
This study developed an empirical habitat suitability model for identifying the optimal habitat of albacore tuna in the South Atlantic Ocean (SAO) by using multisatellite remote sensing data and Taiwanese longline fisheries data between 2009 and 2015. Ageometric mean model with three environmental variables is suggested to be appropriate for explaining the habitat variance of albacore in the SAO. A monthly albacore mean catch per unit effort (CPUE) of larger than 35 individuals/1,000 hooks occurred from April to August and was distributed over 30–40°S. The optimal range of environmental variables in the sea surface temperature, sea surface salinity, and sea surface chlorophyll-a concentrationfor the habitat of albacore are suggested to be approximately 15-20°C, 33.8-35.6 psu, and 0.31-0.61mg/m3, respectively. We discovered a significant positive relationship between the suitable habitat area and nominal CPUE of albacore in the SAO (r = 0.912). Overall, frontal structures play a major role in the stimulation of potential albacore habitats.

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Yen, Kuo-Wei, i 嚴國維. "Establish GIS-based empirical model of habitat suitability for yellowfin tuna in the Western and Central Pacific Ocean". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/51104712429945967204.

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碩士
國立臺灣海洋大學
環境生物與漁業科學學系
98
Empirical Habitat Suitability index (HSI) has been widely used to examine the quality of terrestrial animal, but rarely used in highly migratory fish like tuna. In this study, we used GIS technique to establish empirical models of HSI for yellowfin tuna (YFT) in the Western and Central Pacific Ocean (WCPO). Daily catch data from Taiwanese purse seiner fishery during 2003-2007 were aggregated monthly into 1 by 1 degree and then conduct data match process to obtain monthly average values for the multi-environmental factors, including sea surface temperature (SST), chlorophyll-a (SSC), height (SSH) and salinity (SSS). According to the frequency distribution of each factor on which YFT were caught, we transformed the values of the 4 factors into suitability index (SI) ranged from low to high (0-100%). These SI values were then combined into different empirical HSI models and the optimum one were selected by General Linear model. With the HSI, we have the major results of the analysis are as follows: 1. The optimum ranges of SST, SSC, SSH and SSS for YFT are 27.2～32.5 ℃, 0.02-0.18 mg/m3, 1.51～2.23 m and 34.22-35.25psu. 2. The optimum empirical HSI for TFT’s in the study area is converting the for SI (SST, SSH, SSC and SSS) by arithmetic mean model, by which the correct prediction rate is 71.97%. 3. The HSI began to increase and expand eastwards in March to April and rapid declined in November to next February in the study area. There was an agreement between the average HSI and total YFT catch. Also the high HSI area synchronized with the displacement of CPUE. In this study, we used 4 kinds of surface variables derived from satellite to develop HSI for YFT in the WCPO. The HSI has been proved to a valid index for YFT habitat suitability in large-scale ocean and should be useful to measure the overall habitat able trend for YFT under future climate change in the region. However, the HSI is still unable to be used for fishing ground search due to the limitation of remote sensing data in temporal scale and the lack of subsurface information. There are more effort need to be further inserted for a more applicable HSI in operational level.

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HUNG, I.-CHENG, i 洪懿成. "Habitat suitability empirical model of albacore tuna in the North Pacific Ocean using multi-satellite remote sensing data". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/pumcq4.

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碩士
國立臺灣海洋大學
環境生物與漁業科學學系
105
Empirical habitat suitability index was widely used to detect the habitat variance of marine species in last two decades. Albacore, Thunnus alalunga, is a highly migratory species of important commercial value and widely distribution in three oceans. In this study, the satellite-derived environmental variables, including sea surface temperature (SST), sea surface height anomaly (SSHA), mixed layer depth (MLD), sea surface chlorophyll-a (SSC), eddy kinetic energy (EKE), were used to combine with catch data collecting from Taiwanese longline fisheries during 1998~2012 for establishing five kinds of empirical habitat suitability index, and identifying the optimal habitat of albacore in the North Pacific Ocean. Our results revealed that the high CPUE occurred in November to March in time and distributed over 25~40°N in space. The optimal range of hydrological variables in SST, SSHA, MLD, SSC, EKE, respectively, for the habitat of albacore are 19~22.5°C, 0.3~0.55m, 40~150m, 0.08~ 0.14mg/m3, 0.025~0.15 cm/s2. The Maximum Entropy model (MaxEnt) with five environmental variables was found to be the most appropriate model explaining the habitat variance of albacore in the North Pacific Ocean. The geographic information system maps of fishing period of the predicted HSI values were overlapped by the observed CPUE, suggesting that the model can be used as a tool for reliable prediction of potential fishing grounds with the development of management regulations.

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Wang, Gene-Long, i 王駿穠. "Development and Application of Habitat Suitability Index Model for Avian Commmunity -- An application example of avian community from Huisun Experimentation Forest Station". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/48460468831335205291.

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碩士
國立中興大學
森林學系
90
Abstract Species spatial distribution, species abundance and habitat suitable index are important information for managing wildlife populations and conserving biodiversity. Therefore, the techniques for evaluating wildlife habitats quantitatively are important tools for Ecosystem Management (EM). the main purpose of this study is to integrate the digital photogrammetry and geographic information system(GIS) technology to present the land-use pattern, digital surface model (DSM)、stand closure patterns of a forest ecosystem. GIS database information was used to generalize habitat characteristics of an avian community of Hwui-Sum forest ecosystem located in the center of Taiwan. Habitat Suitable Index model (HSI) was used to simulate the changes of an avian guild by following a typical forest management scenario. The main results of this study are summarized as follow: 1.The technique developed in this study including the application of digital colored aerial photos with forestation map and ground plot survey to generate the land- use map increased the accuracy of habitats interpretation than the photogrammary method used before. The technique generated map date at various precision scales according to the needs of a forest manager. 2.The technique of Integrate digital photogrammetry and GIS technology transformed various types of forest stand information into wildlife habit maps. The habitat maps then provided the basic spatial framework of relate information, which are required for wildlife management. 3.This study used guild concept to modify a single species HSI model to a multiple species HSI models. The multiple species model incorporated with abiotic and biotic environmental factors enhanced the power of predicting the distribution of a species. It can be used for studying the impact of a specific environmental environment change on a species. 4.The model developed in this study was used to simulate a typical forest management scenario in Taiwan.The impact of the forest management scenario on OU guild was demonstrated. This study indicates that the model can be widely applied on simulating the impacts of various forest management strategies on an avian community. The study suggests that: (1) the current forest survey data can be used to predict the distribution of a specific birds by using HSI model, (2) In order to improve power of predicting the distribution of a species, detailed avian and environment parameters are required. (3) Spatial analysis by using GIS technology can provides valuable insight of developing the potential distribution map for an avian community. The technique can be a valuable access for setting up a feasible wildlife management policy. Keyword： geographic information system、digital photogrammetry、guild、scenarios、habitat suitability index model

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Vaz, Leandro Alves. "Optimization of estuarine aquaculture exploitation: modelling approach". Doctoral thesis, 2020. http://hdl.handle.net/10773/30411.

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Aquaculture is one of the fastest growing activities worldwide. In 2006, it already accounted for around 40% of total fish consumption, and since 2012, aquaculture is the main source of marine food supplies. However, this strong and fast development of the sector tends to be reflected in significant environmental impacts and new challenges in the management and planning of the coastal areas. In this context, this work intends to contribute to the sustainability of the sector, by identifying preferential locations to ensure aquaculture expansion and proper operation in a sustainable manner and with minimal environmental impact under optimal hydrodynamic and water quality conditions in Ria de Aveiro (Portugal) and Rias Baixas (Spain). This study is particularly relevant because the mapping of the most suitable areas for aquaculture exploitation has never been performed in any of the study areas, proving to be crucial, not only to demonstrate the potential in this commercial activity and to encourage investment by companies, but mainly to enable an adequate targeting of investments. To achieve this objective, a multidisciplinary methodology was applied, which comprised the following steps: 1 - characterization of hydrodynamic, physical, chemical and biological variables governing aquaculture activities; 2 - implementation, calibration, validation and exploitation of hydrodynamic and water quality models; 3 - development of a habitat model integrating the numerical model results into an exploitation index; 4 - application of a habitat model and mapping of the suitable and unsuitable areas for fish and shellfish exploitation in Ria de Aveiro and Rias Baixas. The results show that 22% of Ria de Aveiro is suitable for fish production (axis of the main channels, from the inlet to the middle of the channels), while the production of pelagic fish in the Rias Baixas is not recommended due to vertical gradients of water temperature and dissolved oxygen. Concerning to bivalves, the habitat model predicts that 31% of Ria de Aveiro is suitable for production. In the Rias Baixas, except for some marginal areas and upstream areas, the suitability for bivalve production is almost complete, confirming the high exploitation of the region. The definition of suitable areas for aquaculture exploitation is highly related with the different geomorphological, hydrological and biogeochemical processes of Ria de Aveiro and Rias Baixas, but also with the vertical structure of the estuarine systems: homogeneous water column (Ria de Aveiro) in opposition to a partially mixed estuarine system (Rias Baixas). Results of Ria de Aveiro indicate that the upstream areas of the lagoon are the most vulnerable from the water quality point of view, highlighting the importance of the advective processes in the lagoon’s water quality, in opposition to Rias Baixas dynamics, where stratification is more relevant. In Rias Baixas, the strong vertical gradient of water temperature and dissolved oxygen disallows fish from having sustainable growth rates. The numerical modelling approach combined with a habitat model allowed to consider a large number of variables, integrating them in order to generate results that are very useful for coastal managers and investors. Therefore, this work shows that the methodology developed here is effective for the identification of favorable areas for the exploitation of species with economic interest, generating a tool that can be replicated and/or adapted in future studies in other coastal systems. Finally, this work demonstrated the potential of hydrodynamic and biogeochemical modelling to support the decision making process in future coastal plans.
A aquacultura é uma das atividades económicas com maior taxa de crescimento. Em 2006, já era responsável por cerca de 40% do consumo total de peixe, e em 2012, consolidou-se como a principal fonte de alimentos de origem marinha. Contudo, este forte e rápido desenvolvimento do setor tende a refletir-se em significativos impactos ambientais, e em novos desafios na gestão e planeamento das zonas costeiras. Neste contexto, este trabalho pretende contribuir para a sustentabilidade do sector, identificando locais preferenciais para a exploração aquícola de forma sustentável, com um impacto ambiental mínimo e um custo relativamente baixo, sob condições ideais de hidrodinâmica e qualidade da água na Ria de Aveiro (Portugal) e Rias Baixas (Espanha), os dois sistemas com maior exploração no NW da Península Ibérica. Este estudo torna-se particularmente relevante porque o mapeamento das localizações mais adequadas à exploração aquícola nunca foi efetuado em nenhuma das áreas de estudo, revelando-se fulcral, não só para demonstrar o potencial da atividade comercial e incentivar o investimento das empresas, mas principalmente para permitir um direcionamento adequado dos investimentos, e contribuir para a sustentabilidade do setor. Para alcançar este objetivo foi aplicada uma metodologia multidisciplinar que compreendeu a realização dos seguintes passos: 1 - caracterização das variáveis hidrodinâmicas, físicas, químicas e biológicas importantes para a aquacultura; 2 - implementação, calibração, validação e aplicação de modelos hidrodinâmicos e de qualidade da água; 3 - desenvolvimento de um modelo de habitat, para transformação dos resultados dos modelos numéricos, num índice de exploração; 4 - aplicação do modelo de habitat, e mapeamento das zonas mais adequados à exploração de peixes e bivalves na Ria de Aveiro e Rias Baixas. Os resultados evidenciam que 22% da Ria de Aveiro é adequada para a produção de peixes (eixo dos principais canais, desde a embocadura até à zona intermédia dos canais), enquanto que a produção de peixes pelágicos nas Rias Baixas não é aconselhável, devido aos gradientes verticais de temperatura da água e de oxigénio dissolvido. Relativamente aos bivalves, o modelo de habitat prevê que 31% da Ria de Aveiro é adequada à sua produção. Nas Rias Baixas, exceptuando algumas zonas marginais e perto das cabeceiras, a adequabilidade para a produção de bivalves é quase total, confirmando a elevada exploração que se verifica na região. A definição das áreas propícias para a exploração aquícola está altamente relacionada com os diferentes processos geomorfológicos, hidrológicos e biogeoquímicos que ocorrem na Ria de Aveiro e nas Rias Baixas, mas também com a estrutura vertical dos sistemas estuarinos: uma coluna de água homogénea (Ria de Aveiro) em oposição a um sistema estuarino parcialmente estratificado (Rias Baixas). Os resultados para a Ria de Aveiro indicam que as cabeceiras dos principais canais são as áreas mais vulneráveis do ponto de vista da qualidade da água, evidenciando a importância da adveção nos processos ecológicos, em oposição à dinâmica das Rias Baixas, onde a estratificação adquire maior relevância. Nestes estuários, o forte gradiente vertical da temperatura da água e do oxigénio dissolvido impede que os peixes possuam taxas de crescimento sustentáveis. A abordagem de modelação numérica combinada com um modelo de habitat permitiu considerar um elevado número de variáveis, integrando-as de forma a gerar resultados de grande utilidade para gestores e investidores do setor aquícola. Consequentemente, este trabalho mostra que a metodologia aqui desenvolvida é eficaz para a identificação de locais propícios para a exploração de espécies de interesse económico, gerando uma ferramenta que pode ser replicada e/ou adaptada em estudos futuros a realizar noutros sistemas costeiros. Finalmente, este trabalho demonstrou o potencial da modelação hidrodinâmica e biogeoquímica no suporte ao processo de tomada de decisão em futuros planos de ordenamento das zonas costeiras.
Programa Doutoral em Ciência, Tecnologia e Gestão do Mar

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Kennedy, Bradley. "The new invasive Odontites serotina: impacts, responses and predictive model". 2012. http://hdl.handle.net/1993/5031.

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Invasive alien species (IAS) pose a serious threat to ecosystems and societies worldwide. Local ecological knowledge (LEK) is increasingly valued as a means of understanding environmental issues; however, its application in the context of IAS research has been limited. The overall objective of this study was to document the LEK of farmers and Weed Supervisors to gain insight into a recent IAS, Odontites serotina. I conducted semi-structured interviews with farmers and Weed Supervisors with O. serotina management experience. Results indicated that the socio-economic impacts for farmers were severe in affected rural communities. However, participants had developed promising control techniques, including the application of compost mulch. I used this LEK as well as data on species occurrence, environmental variables, and measures of propagule pressure to forecast the potential distribution of O. serotina across Manitoba. The risk map generated will be useful for guiding future monitoring and public outreach efforts.

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Mwambo, Francis Molua. "Human and climatic change impact modelling on the habitat suitability for the chimpanzee (Pan troglodytes ellioti) – Case study: The proposed Mount Cameroon National Park". Master's thesis, 2010. http://hdl.handle.net/10362/2734.

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Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies
The prediction of species' distribution is fundamental to many applications in ecology, wildlife conservation and the science of evolution. Variations in the abundance within a species' geographic range provide the connection between the disciplines of ecology, geostatistics and biogeography. Species predictive modelling is quite intricate considering the spatial and aspatial variables that both play interactive roles in predicting a species' occurrence. Like many primates across Africa, Pan troglodytes ellioti has both the least geographic distribution and population relative to the other chimpanzee subspecies continent wide. With the proposed Mount Cameroon National Park as the study area, predictions displayed as maps further enhance spatial visualisation. Predictions in Maxent had an estimated accuracy assessment of approximately 0.7 and 67.41% being currently suitable respectively. The observed shift in the habitat suitability from lower to higher altitudes suggests climatic conditions prevailing in the suitable range will likely be attainable only at much higher altitudes in the future. A likely consequence on species shall be to ascend towards the summit in order to meet their needs both physiologically and resource wise.

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Campbell, Karen Lea. "Testing habitat suitability models for Roosevelt elk". Thesis, 1995. http://hdl.handle.net/2429/3764.

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Seasonal habitat suitability models for Roosevelt elk, Cervus elaphus roosevelti, (Brunt 1991) were tested using two distinctly different study areas on northern Vancouver Island, British Columbia. Locations for 5 radio-collared elk, obtained approximately twice per week by telemetry from May 1992 to August 1993, were used to test the models. I used the adaptive kernel method to estimate seasonal home ranges from each elk's locations. Habitat suitability values for summer, mild winter, and severe winter were calculated across each study area on a geographic information system (GIS), using input variables from forest cover, topology, and understory coverages. I compared the suitability values of elk locations to values within home ranges and across study areas, and the suitability values of seasonal home ranges to those across the study areas. The home ranges were further compared with equal sized, circular areas randomly placed in the study areas. Because elk generally used areas of higher suitability than expected, I concluded that the model had some ability to predict areas which contained suitable elk habitat. I also identified limitations of the model.

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Lockett, Daniel Edwin IV. "A Bayesian approach to habitat suitability prediction". Thesis, 2012. http://hdl.handle.net/1957/28788.

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For the west coast of North America, from northern California to southern Washington, a habitat suitability prediction framework was developed to support wave energy device siting. Concern that wave energy devices may impact the seafloor and benthos has renewed research interest in the distribution of marine benthic invertebrates and factors influencing their distribution. A Bayesian belief network approach was employed for learning species-habitat associations for Rhabdus rectius, a tusk-shaped marine infaunal Mollusk. Environmental variables describing surficial geology and water depth were found to be most influential to the distribution of R. rectius. Water property variables, such as temperature and salinity, were less influential as distribution predictors. Species-habitat associations were used to predict habitat suitability probabilities for R. rectius, which were then mapped over an area of interest along the south-central Oregon coast. Habitat suitability prediction models tested well against data withheld for crossvalidation supporting our conclusion that Bayesian learning extracts useful information available in very small, incomplete data sets and identifies which variables drive habitat suitability for R. rectius. Additionally, Bayesian belief networks are easily updated with new information, quantitative or qualitative, which provides a flexible mechanism for multiple scenario analyses. The prediction framework presented here is a practical tool informing marine spatial planning assessment through visualization of habitat suitability.
Graduation date: 2012

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Just, Peter. "Entwicklung eines statistischen Habitateignungsmodells zur räumlichen Vorhersage der Vorkommenswahrscheinlichkeit des Wachtelkönigs (Crex crex L.) im Nationalpark Unteres Odertal". Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-B32D-E.

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