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Author: L. Scott Mills
Publisher:
ISBN:
Category : Grizzly bear
Languages : en
Pages : 11
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Book Description
Population viability analysis programs are being used increasingly in research and management applications, but there has not been a systematic study of the congruence of different program predictions based on a single data set. We performed such an analysis using four population viability analysis computer programs: GAPPS, INMAT, RAMAS/AGE, and VORTEX. The standardized demographic rates used in all programs were generalized from hypothetical increasing and decreasing grizzly bear (Ursus arctos horribilis) populations. Idiosyncracies of input format for each program led to minor differences in intrinsic growth rates that translated into striking differences in estimates of extinction rates and expected population size. In contrast, the addition of demographic stochasticity, environmental stochasticity, and inbreeding costs caused only a small divergence in viability predictions. But, the addition of density dependence caused large deviations between the programs despite our best attempts to use the same density-dependent functions. Population viability programs differ in how density dependence is incorporated, and the necessary functions are difficult to parameterize accurately. Thus, we recommend that unless data clearly suggest a particular density-dependent model, predictions based on population viability analysis should include at least one scenario without density dependence. Further, we describe output metrics that may differ between programs; development of future software could benefit from standardized input and output formats across different programs.
Author: L. Scott Mills
Publisher:
ISBN:
Category : Grizzly bear
Languages : en
Pages : 11
Get Book Here
Book Description
Population viability analysis programs are being used increasingly in research and management applications, but there has not been a systematic study of the congruence of different program predictions based on a single data set. We performed such an analysis using four population viability analysis computer programs: GAPPS, INMAT, RAMAS/AGE, and VORTEX. The standardized demographic rates used in all programs were generalized from hypothetical increasing and decreasing grizzly bear (Ursus arctos horribilis) populations. Idiosyncracies of input format for each program led to minor differences in intrinsic growth rates that translated into striking differences in estimates of extinction rates and expected population size. In contrast, the addition of demographic stochasticity, environmental stochasticity, and inbreeding costs caused only a small divergence in viability predictions. But, the addition of density dependence caused large deviations between the programs despite our best attempts to use the same density-dependent functions. Population viability programs differ in how density dependence is incorporated, and the necessary functions are difficult to parameterize accurately. Thus, we recommend that unless data clearly suggest a particular density-dependent model, predictions based on population viability analysis should include at least one scenario without density dependence. Further, we describe output metrics that may differ between programs; development of future software could benefit from standardized input and output formats across different programs.
Author: Steven R. Beissinger
Publisher: University of Chicago Press
ISBN: 9780226041773
Category : Nature
Languages : en
Pages : 616
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Book Description
Many of the world's leading conservation and population biologists evaluate what has become a key tool in estimating extinction risk and evaluating potential recovery strategies - population viability analysis, or PVA.
Author: Christy A. Brigham
Publisher: Springer Science & Business Media
ISBN: 3662093898
Category : Science
Languages : en
Pages : 370
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Book Description
Providing a quantitative assessment of threatened plant populations, that holds for varying management scenarios, has become an essential part of conservation planning. Here, renowned plant ecologists provide information on: major threats to plants, when and where to conduct a plant viability assessment (PVA), what type of PVA to conduct, what alternative options to PVA are available, what information is required for which kind of viability assessment, what attributes of the population in question should be considered, and what the limits of the PVA would be. As such, this volume can be used as a training tool for the environmental manager or a teaching aid for reviewing the current state of knowledge on plant population viability.
Author: Luigi Boitani
Publisher: Columbia University Press
ISBN: 0231113412
Category : Nature
Languages : en
Pages : 477
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Book Description
This book provides an analysis of frequently used research techniques in animal ecology, identifying their limitations and misuses, as well as possible solutions to avoid such pitfalls. The contributors provide an overarching account of central theoretical and methodological controversies. The editors have forged comprehensive presentations of key topics in animal ecology, such as territory and home range estimates, habitation evaluation, population viability analysis, GIS mapping, and measuring the dynamics of societies.
Author: Scott Ferson
Publisher: Springer Science & Business Media
ISBN: 0387226486
Category : Science
Languages : en
Pages : 334
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Book Description
Quantitative methods are needed in conservation biology more than ever as an increasing number of threatened species find their way onto international and national “red lists. ” Objective evaluation of population decline and extinction probability are required for sound decision making. Yet, as our colleague Selina Heppell points out, population viability analysis and other forms of formal risk assessment are underused in policy formation because of data uncertainty and a lack of standardized methodologies and unambiguous criteria (i. e. , “rules of thumb”). Models used in conservation biology range from those that are purely heuristic to some that are highly predictive. Model selection should be dependent on the questions being asked and the data that are available. We need to develop a toolbox of quantitative methods that can help scientists and managers with a wide range of systems and that are subject to varying levels of data uncertainty and environmental variability. The methods outlined in the following chapters represent many of the tools needed to fill that toolbox. When used in conjunction with adaptive management, they should provide information for improved monitoring, risk assessment, and evaluation of management alternatives. The first two chapters describe the application of methods for detecting trends and extinctions from sighting data. Presence/absence data are used in general linear and additive models in Chapters 3 and 4 to predict the extinction proneness of birds and to build habitat models for plants.
Author: Steward Pickett
Publisher: Springer Science & Business Media
ISBN: 1461560039
Category : Science
Languages : en
Pages : 477
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Book Description
From its inception, the U.S. Department of the Interior has been charged with a conflicting mission. One set of statutes demands that the department must develop America's lands, that it get our trees, water, oil, and minerals out into the marketplace. Yet an opposing set of laws orders us to conserve these same resources, to preserve them for the long term and to consider the noncommodity values of our public landscape. That dichotomy, between rapid exploitation and long-term protection, demands what I see as the most significant policy departure of my tenure in office: the use of science-interdisciplinary science-as the primary basis for land management decisions. For more than a century, that has not been the case. Instead, we have managed this dichotomy by compartmentalizing the American landscape. Congress and my predecessors handled resource conflicts by drawing enclosures: "We'll create a national park here," they said, "and we'll put a wildlife refuge over there." Simple enough, as far as protection goes. And outside those protected areas, the message was equally simplistic: "Y'all come and get it. Have at it." The nature and the pace of the resource extraction was not at issue; if you could find it, it was yours.
Author: Fred W. Allendorf
Publisher: John Wiley & Sons
ISBN: 1444309056
Category : Science
Languages : en
Pages : 664
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Book Description
Conservation and the Genetics of Populations gives acomprehensive overview of the essential background, concepts, andtools needed to understand how genetic information can be used todevelop conservation plans for species threatened withextinction. Provides a thorough understanding of the genetic basis ofbiological problems in conservation. Uses a balance of data and theory, and basic and appliedresearch, with examples taken from both the animal and plantkingdoms. An associated website contains example data sets and softwareprograms to illustrate population genetic processes and methods ofdata analysis. Discussion questions and problems are included at the end ofeach chapter to aid understanding. Features Guest Boxes written by leading people in the fieldincluding James F. Crow, Nancy FitzSimmons, Robert C. Lacy, MichaelW. Nachman, Michael E. Soule, Andrea Taylor, Loren H. Rieseberg,R.C. Vrijenhoek, Lisette Waits, Robin S. Waples and AndrewYoung. Supplementary information designed to support Conservationand the Genetics of Populations including: Downloadable sample chapter Answers to questions and problems Data sets illustrating problems from the book Data analysis software programs Website links An Instructor manual CD-ROM for this title is available. Pleasecontact our Higher Education team at ahref="mailto:
[email protected]"
[email protected]/afor more information.
Author: Lawrence W. Barnthouse
Publisher: CRC Press
ISBN: 1000687503
Category : Law
Languages : en
Pages : 448
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Book Description
Most ecological risk assessments consider the risk to individual organisms or organism-level attributes. From a management perspective, however, risks to population-level attributes and processes are often more relevant. Despite many published calls for population risk assessment and the abundance of available scientific research and technical tool
Author: Klaus von Gadow
Publisher: Springer Science & Business Media
ISBN: 9401729050
Category : Nature
Languages : en
Pages : 252
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Book Description
Due to the long-term planning horizons and the great variety of natural, economic, and operational hazards affecting forest ecosystems, uncertainty and multiple risk are typical aspects of forest management. Applications of risk analysis are surprisingly rare, in spite of the rich assortment of sophisticated forest planning tools that are available today. The objective of this particular volume within the book series Managing Forest Ecosystems is to present state-of-the-art research results, concepts, and techniques regarding the assessment and evaluation of natural hazards and the analysis of risk and uncertainty relating to forest management. Various aspects of risk analysis are covered, including examples of specific modelling tools. The book is divided into three sections covering ecological perspectives, applications in engineering and planning, and methods applicable to economics and policy.
Author: Russell Lande
Publisher: OUP Oxford
ISBN: 9780198525257
Category : Mathematics
Languages : en
Pages : 698
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Book Description
1. Demographic and environmental stochasticity -- 2. Extinction dynamics -- 3. Age structure -- 4. Spatial structure -- 5. Population viability analysis -- 6. Sustainable harvesting -- 7. Species diversity -- 8. Community dynamics.
