Download or read book Improving Species Distribution Models with Bias Correction and Geographically Weighted Regression written by Richard Inman and published by . This book was released on 2018 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work investigates the effects of non-random sampling on our understanding of species distributions and their niches. In its most general form, bias is systematic error that can obscure interpretation of analytical results by skewing samples away from the average condition of the system they represent. Here I use species distribution modelling (SDM), virtual species, and multiscale geographically weighted regression (MGWR) to explore how sampling bias can alter our perception of broad patterns of biodiversity by distorting spatial predictions of habitat, a key characteristic in biogeographic studies. I use three separate case studies to explore: 1) How methods to account for sampling bias in species distribution modeling may alter estimates of species distributions and species-environment relationships, 2) How accounting for sampling bias in fossil data may change our understanding of paleo-distributions and interpretation of niche stability through time (i.e. niche conservation), and 3) How a novel use of MGWR can account for environmental sampling bias to reveal landscape patterns of local niche differences among proximal, but non-overlapping sister taxa. Broadly, my work shows that sampling bias present in commonly used federated global biodiversity observations is more than enough to degrade model performance of spatial predictions and niche characteristics. Measures commonly used to account for this bias can negate much loss, but only in certain conditions, and did not improve the ability to correctly identify explanatory variables or recreate species-environment relationships. Paleo-distributions calibrated on biased fossil records were improved with the use of a novel method to directly estimate the biased sampling distribution, which can be generalized to finer time slices for further paleontological studies. Finally, I show how a novel coupling of SDM and MGWR can illuminate local differences in niche separation that more closely match landscape genotypic variability in the two North American desert tortoise species than does their current taxonomic delineation.
Download or read book Geographically Weighted Regression written by A. Stewart Fotheringham and published by John Wiley & Sons. This book was released on 2003-02-21 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geographical Weighted Regression (GWR) is a new local modelling technique for analysing spatial analysis. This technique allows local as opposed to global models of relationships to be measured and mapped. This is the first and only book on this technique, offering comprehensive coverage on this new 'hot' topic in spatial analysis. * Provides step-by-step examples of how to use the GWR model using data sets and examples on issues such as house price determinants, educational attainment levels and school performance statistics * Contains a broad discussion of and basic concepts on GWR through to ideas on statistical inference for GWR models * uniquely features accompanying author-written software that allows users to undertake sophisticated and complex forms of GWR within a user-friendly, Windows-based, front-end (see book for details).
Download or read book Wrong But Useful Regional Species Distribution Models May Not be Improved by Range wide Data Under Biased Sampling written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Species distribution modeling (SDM) is an essential method in ecology and conservation. SDMs are often calibrated within one country's borders, typically along a limited environmental gradient with biased and incomplete data, making the quality of these models questionable. In this study, we evaluated how adequate are national presence‐only data for calibrating regional SDMs. We trained SDMs for Egyptian bat species at two different scales: only within Egypt and at a species‐specific global extent. We used two modeling algorithms: Maxent and elastic net, both under the point‐process modeling framework. For each modeling algorithm, we measured the congruence of the predictions of global and regional models for Egypt, assuming that the lower the congruence, the lower the appropriateness of the Egyptian dataset to describe the species' niche. We inspected the effect of incorporating predictions from global models as additional predictor ("prior") to regional models, and quantified the improvement in terms of AUC and the congruence between regional models run with and without priors. Moreover, we analyzed predictive performance improvements after correction for sampling bias at both scales. On average, predictions from global and regional models in Egypt only weakly concur. Collectively, the use of priors did not lead to much improvement: similar AUC and high congruence between regional models calibrated with and without priors. Correction for sampling bias led to higher model performance, whatever prior used, making the use of priors less pronounced. Under biased and incomplete sampling, the use of global bats data did not improve regional model performance. Without enough bias‐free regional data, we cannot objectively identify the actual improvement of regional models after incorporating information from the global niche. However, we still believe in great potential for global model predictions to guide future surveys and improve regional sampling in data‐poor regions. Abstract : Species distribution models are often calibrated within one country's borders, typically along a limited environmental gradient with biased and incomplete data, making the quality of these models questionable. In this study, we evaluated how adequate are national presence‐only data for calibrating regional SDMs and how much improvement occurs after incorporating information from global models as additional predictor (priors). Correction for sampling bias led to higher model performance, whatever prior used, making the use of priors less pronounced. Under biased and incomplete sampling, the use of global data did not improve regional model performance. However, we still believe in great potential for global model predictions to guide future surveys and improve regional sampling in data‐poor regions.
Download or read book Thesis and Dissertation Writing in a Second Language written by Brian Paltridge and published by Routledge. This book was released on 2019-07-25 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully updated and packed with new material, the second edition of Thesis and Dissertation Writing in a Second Language is the ideal guide for non-native speaker students and their supervisors working on writing a thesis or dissertation in English. Considering the purposes of thesis and dissertation of writing alongside writer/reader relationships, this book uses accessible language and practical examples to discuss issues that are crucial to successful thesis and dissertation writing. This edition offers: Insights into the experience of being a doctoral writer, issues of writer identity, and writing with authority Typical language and discourse features of theses and dissertations Advice on the structure and organisation of key sections Suggestions for online resources which support writing Extracts from completed theses and dissertations Guidance on understanding examiner expectations Advice on publishing from a PhD Suitable for students from all disciplines, Thesis and Dissertation Writing in a Second Language is essential reading for non-native speaker students looking to complete a thesis or dissertation in English.
Download or read book Predicting Species Occurrences written by J. Michael Scott and published by Island Press. This book was released on 2002-02 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predictions about where different species are, where they are not, and how they move across a landscape or respond to human activities -- if timber is harvested, for instance, or stream flow altered -- are important aspects of the work of wildlife biologists, land managers, and the agencies and policymakers that govern natural resources. Despite the increased use and importance of model predictions, these predictions are seldom tested and have unknown levels of accuracy.Predicting Species Occurrences addresses those concerns, highlighting for managers and researchers the strengths and weaknesses of current approaches, as well as the magnitude of the research required to improve or test predictions of currently used models. The book is an outgrowth of an international symposium held in October 1999 that brought together scientists and researchers at the forefront of efforts to process information about species at different spatial and temporal scales. It is a comprehensive reference that offers an exhaustive treatment of the subject, with 65 chapters by leading experts from around the world that: review the history of the theory and practice of modeling and present a standard terminology examine temporal and spatial scales in terms of their influence on patterns and processes of species distribution offer detailed discussions of state-of-the-art modeling tools and descriptions of methods for assessing model accuracy discuss how to predict species presence and abundance present examples of how spatially explicit data on demographics can provide important information for managers An introductory chapter by Michael A. Huston examines the ecological context in which predictions of species occurrences are made, and a concluding chapter by John A. Wiens offers an insightful review and synthesis of the topics examined along with guidance for future directions and cautions regarding misuse of models. Other contributors include Michael P. Austin, Barry R. Noon, Alan H. Fielding, Michael Goodchild, Brian A. Maurer, John T. Rotenberry, Paul Angermeier, Pierre R. Vernier, and more than a hundred others.Predicting Species Occurrences offers important new information about many of the topics raised in the seminal volume Wildlife 2000 (University of Wisconsin Press, 1986) and will be the standard reference on this subject for years to come. Its state-of-the-art assessment will play a key role in guiding the continued development and application of tools for making accurate predictions and is an indispensable volume for anyone engaged in species management or conservation.
Download or read book Spatial Analysis Methods and Practice written by George Grekousis and published by Cambridge University Press. This book was released on 2020-06-11 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introductory overview of spatial analysis and statistics through GIS, including worked examples and critical analysis of results.
Download or read book Mapping Species Distributions written by Janet Franklin and published by . This book was released on 2014-05-14 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive summary of species distribution modeling methods integrating ecological and statistical models with spatial data, and a framework for implementation.
Download or read book Invasive Species written by Andrew P. Robinson and published by Cambridge University Press. This book was released on 2017-06-08 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the latest risk-based techniques to protect national interests from invasive pests and pathogens before, at and within national borders.
Download or read book Predictive Species and Habitat Modeling in Landscape Ecology written by C. Ashton Drew and published by Springer Science & Business Media. This book was released on 2010-11-25 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most projects in Landscape Ecology, at some point, define a species-habitat association. These models are inherently spatial, dealing with landscapes and their configurations. Whether coding behavioral rules for dispersal of simulated organisms through simulated landscapes, or designing the sampling extent of field surveys and experiments in real landscapes, landscape ecologists must make assumptions about how organisms experience and utilize the landscape. These convenient working postulates allow modelers to project the model in time and space, yet rarely are they explicitly considered. The early years of landscape ecology necessarily focused on the evolution of effective data sources, metrics, and statistical approaches that could truly capture the spatial and temporal patterns and processes of interest. Now that these tools are well established, we reflect on the ecological theories that underpin the assumptions commonly made during species distribution modeling and mapping. This is crucial for applying models to questions of global sustainability. Due to the inherent use of GIS for much of this kind of research, and as several authors’ research involves the production of multicolored map figures, there would be an 8-page color insert. Additional color figures could be made available through a digital archive, or by cost contributions of the chapter authors. Where applicable, would be relevant chapters’ GIS data and model code available through a digital archive. The practice of data and code sharing is becoming standard in GIS studies, is an inherent method of this book, and will serve to add additional research value to the book for both academic and practitioner audiences.
Download or read book Mapping Species Distributions written by Janet Franklin and published by Cambridge University Press. This book was released on 2010-01-07 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maps of species' distributions or habitat suitability are required for many aspects of environmental research, resource management and conservation planning. These include biodiversity assessment, reserve design, habitat management and restoration, species and habitat conservation plans and predicting the effects of environmental change on species and ecosystems. The proliferation of methods and uncertainty regarding their effectiveness can be daunting to researchers, resource managers and conservation planners alike. Franklin summarises the methods used in species distribution modeling (also called niche modeling) and presents a framework for spatial prediction of species distributions based on the attributes (space, time, scale) of the data and questions being asked. The framework links theoretical ecological models of species distributions to spatial data on species and environment, and statistical models used for spatial prediction. Providing practical guidelines to students, researchers and practitioners in a broad range of environmental sciences including ecology, geography, conservation biology, and natural resources management.
Download or read book Habitat Suitability and Distribution Models written by Antoine Guisan and published by Cambridge University Press. This book was released on 2017-09-14 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the key stages of niche-based habitat suitability model building, evaluation and prediction required for understanding and predicting future patterns of species and biodiversity. Beginning with the main theory behind ecological niches and species distributions, the book proceeds through all major steps of model building, from conceptualization and model training to model evaluation and spatio-temporal predictions. Extensive examples using R support graduate students and researchers in quantifying ecological niches and predicting species distributions with their own data, and help to address key environmental and conservation problems. Reflecting this highly active field of research, the book incorporates the latest developments from informatics and statistics, as well as using data from remote sources such as satellite imagery. A website at www.unil.ch/hsdm contains the codes and supporting material required to run the examples and teach courses.
Download or read book Development of Integrated Species Distribution Models to Improve Occupancy Predictions of Avian Species of Concern written by Fiona Lunt and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Species distribution models have the potential to improve our understanding of the relationship among species, communities, and their environment. This modeling framework is further improved through the process of data integration, which incorporates multiple data sources into a single model and has the potential to improve predictive accuracy if certain data biases are accounted for. The first chapter of this project aims to improve the existing integrated species distribution model framework by addressing how to best treat non-standardized and older sources of data. Using the community science platform eBird, we build a set of hierarchical occupancy models that systematically test how to filter the data, how to incorporate effort to account for observation errors, and how to integrate the additional data sources, the 2nd Pennsylvania Breeding Bird Atlas (BBA) and the North American Breeding Bird Survey (BBS), into a single integrated model, as well as whether older data from these sources is beneficial for predicting contemporary distributions. These models are tested with four avian species on the Pennsylvania State Wildlife Action Plan's list of species with greatest conservation need-- Canada Warbler (Cardellina canadensis), Cerulean Warbler (Setophaga cerulea), Golden-winged Warbler (Vermivora chrysoptera), and Wood Thrush (Hylocichla mustelina). We find that filtering eBird data by limiting spatial variability and spatial balancing improves the dataset's predictive accuracy for usage in a formal joint-likelihood model. Additionally, using an alternative integration method by treating the data as a covariate offers a separate improvement on the joint-likelihood model. Treating older data as a model covariate, as opposed to weighing it the same as modern data, also improves model fit. These results suggest that non-standardized data like eBird and older data like BBA are useful for species distribution models if proper steps are taken to filter and integrate. In the second chapter, we apply some of these techniques to a distributional assessment of Golden-winged Warbler (Vermivora chrysoptera), a species facing steep population declines, and its competitor the Blue-winged Warbler (Vermivora cyanoptera). We asked whether incorporating a co-occurrence model improves occupancy predictions for the former species and if there are any environmental relationships that predict distributional overlap in their breeding range in Pennsylvania. We find that model predictions improve when using Blue-winged Warbler occupancy as a predictor of Golden-winged Warbler presence, and that the likelihood a Golden-winged Warbler is present greatly increases if Blue-winged Warbler is present. We did not find any significant environmental predictors of co-occurrence. Utilizing a fully integrated model for this chapter was useful in capturing more information about these uncommon species, which may have not been as easily achieved with a single dataset. Overall, our analyses highlight the benefits of properly structuring and integrating multiple data sources into species distribution models and offer methods of expansion for more specific ecological questions, such as through incorporating a co-occurrence structure.
Download or read book Species Distribution Modeling written by Lifei Wang and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biology and Ecology of Antarctic Krill written by Volker Siegel and published by Springer. This book was released on 2016-08-03 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a unique insight into the current knowledge of krill population dynamics including distribution, biomass, production, recruitment, growth and mortality rates. Detailed analysis is provided on food and feeding, reproduction and krill behaviour. The volume provides an overview on the aspects of natural challenges to the species, which involve predation, parasites and the commercial exploitation of the resource and its management. A chapter on genetics shows the results of population subdivision and summarizes recent work on sequencing transcriptomes for studying gene function as part of the physiology of live krill. The focus of Chapter 4 is on physiological functions such as biochemical composition, metabolic activity and growth change with ontogeny and season; and will demonstrate which environmental factors are the main drivers for variability. Further discussed in this chapter are the bottle necks which occur in the annual life cycle of krill, and the mechanisms krill have adapted to cope with severe environmental condition.
Download or read book Generalised Thermostatistics written by Jan Naudts and published by Springer Science & Business Media. This book was released on 2011-02-07 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: The domain of non-extensive thermostatistics has been subject to intensive research over the past twenty years and has matured significantly. Generalised Thermostatistics cuts through the traditionalism of many statistical physics texts by offering a fresh perspective and seeking to remove elements of doubt and confusion surrounding the area. The book is divided into two parts - the first covering topics from conventional statistical physics, whilst adopting the perspective that statistical physics is statistics applied to physics. The second developing the formalism of non-extensive thermostatistics, of which the central role is played by the notion of a deformed exponential family of probability distributions. Presented in a clear, consistent, and deductive manner, the book focuses on theory, part of which is developed by the author himself, but also provides a number of references towards application-based texts. Written by a leading contributor in the field, this book will provide a useful tool for learning about recent developments in generalized versions of statistical mechanics and thermodynamics, especially with respect to self-study. Written for researchers in theoretical physics, mathematics and statistical mechanics, as well as graduates of physics, mathematics or engineering. A prerequisite knowledge of elementary notions of statistical physics and a substantial mathematical background are required.
Download or read book Increasing Accuracy and Explanatory Power of Species Distribution Models with Examples from the Carrizo Plain written by William Timothy Miles Bean and published by . This book was released on 2009 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Analysis in Field Primatology written by Francine L. Dolins and published by Cambridge University Press. This book was released on 2021-02-18 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: A primatologist's guide to using geographic information systems (GIS); from mapping and field accuracy, to tracking travel routes and the impact of logging.
