Interpretation and Implications of Variability in Ecological Systems

Interpretation and Implications of Variability in Ecological Systems
Author: Robert Klinger
Publisher: Frontiers Media SA
Total Pages: 206
Release: 2024-07-22
Genre: Science
ISBN: 2832551734

Numerous hypotheses have been proposed to explain the dynamics in abundance of individual species, how species interact, how communities assemble, and how interactions between biotic and abiotic processes shape ecosystem stability. Many if not most of these hypotheses find some degree of support, but often only within relatively narrow spatial and temporal ranges. This is because conditions vary over time and from place to place, and so the strength and extent of processes that were the focus of a given a hypothesis become altered by other forces. Ecologists have confronted variability from two perspectives; conceptual and statistical. Conceptually, spatial and temporal variability are now recognized as being scale dependent and hierarchical. Statistically, there are many models that ecologists readily use that account for the hierarchical and scale-dependence of variability present in many datasets. But linking the two perspectives into a meaningful understanding of what variability means in real systems has been much less successful. For example, it is common to see studies where the fixed effects of a generalized linear mixed model are reported, but very often random effects are completely ignored or, at best, given scant attention. The likelihood of this being a significant problem increases greatly in what are rapidly becoming more common studies that utilize datasets spanning long temporal and/or large spatial scales, or when extreme and often unpredictable events (gray and black swans) occur.

Survey Designs and Statistical Methods for the Estimation of Avian Population Trends

Survey Designs and Statistical Methods for the Estimation of Avian Population Trends
Author: John R. Sauer
Publisher:
Total Pages: 184
Release: 1990
Genre: Bird populations
ISBN:

Proceedings of a workshop on the analysis of avian population trends, held April 1988 in Laurel, Maryland. Describes the design of major avian surveys, presents major analytical methods used to estimate population trends, and provides analyses of scissor-tailed flycatcher data set.

Survey Designs and Statistical Methods for the Estimation of Avian Population Trends

Survey Designs and Statistical Methods for the Estimation of Avian Population Trends
Author: U.S. Fish and Wildlife Service
Publisher:
Total Pages: 166
Release: 1990
Genre: Bird populations
ISBN:

Proceedings of a workshop on the analysis of avian population trends, held April 1988 in Laurel, Maryland. Describes the design of major avian surveys, presents major analytical methods used to estimate population trends, and provides analyses of scissor-tailed flycatcher data set.

A Best Practice Guide for Wild Bird Monitoring Schemes

A Best Practice Guide for Wild Bird Monitoring Schemes
Author: Petr Voříšek
Publisher: Ceska Spolecnost Ornitologicka Cso
Total Pages: 154
Release: 2008
Genre: Science
ISBN:

This book summarises recommendations on establishing, running andimproving national wild bird monitoring schemes. The methodologyis described in details and includes field methods, samplingdesign, data management and analysis, and communication; includingcase studies from various countries.The Best Practice Guide is not intended to replace existingtextbooks and methodological papers. The aim is to guidecoordinators of schemes in designing and running a scheme in orderto keep high methodological standards and avoid obvious mistakes.The book has nine chapters covering planning a scheme, surveydesign and selection of sample plots or field methods, it tacklesalso the problem of bird detectability and distance sampling, datamanagement and analysis, and principles and recommendations forusing the results for nature conservation and communication. Casestudies come from several European countries and cover subjectssuch as sampling design, field methods, working with volunteerfieldworkers, and setting up an on-line database. Finalrecommendations in a form of a list of 'things best to do' and'things best to avoid' are part of the publication too.

Monitoring Bird Populations by Point Counts

Monitoring Bird Populations by Point Counts
Author: C. Ralph
Publisher: CreateSpace
Total Pages: 190
Release: 2012-04-29
Genre:
ISBN: 9781475278750

Point counts of buds are the most widely used quantitative method and involve an observer recording buds from a single point for a standardized time period. In response to the need for standardization of methods to monitor bird populations by census, various investigators met in Maryland in late fall 1991 to evaluate point counts. Their objectives were to present data from various investigations working under a wide variety of conditions, and to examine various aspects of point count methodology. This volume contains the papers given at the workshop, as well as a few additional relevant papers that subsequently have been submitted to the technical coordinators. Statistical aspects of sampling and analysis were discussed and applied to the objectives of point counts. From this base, at interactive sessions the participants discussed and agreed upon standards of point counts that should have wide applicability to a variety of habitats and terrain. The final chapter presents these standards and their applications to point count methodology. Forest Service, US Department of Agriculture

Monitoring Bird Populations in Small Geographic Areas

Monitoring Bird Populations in Small Geographic Areas
Author:
Publisher:
Total Pages: 59
Release: 2006
Genre: Bird populations
ISBN: 9780662428237

Numerous methods exist for monitoring bird populations, and there is a large literature describing them. There are few resources, however, that provide comprehensive advice on every step of organizing and carrying out a survey, from the early stages of planning to final use of the data. Even fewer resources are designed to meet the needs of a wide variety of potential users, from amateurs interested in change of bird life in a local study preserve to professionals testing hypotheses on the response of birds to habitat management, although much of the advice should be the same for every monitoring program. Whether survey objectives are very modest or rigorously scientific, samples must be sufficiently numerous and well distributed to provide meaningful results, and the survey should be well designed to ensure that the money and effort going into it are not wasted. This document is intended to be a complete resource for anyone planning to organize monitoring of noncolonial landbirds within a relatively small geographic area (e.g., from the size of a woodlot to a large park). The first of its two parts provides background explaining the importance of good study design and gives specific advice on all aspects of project planning and execution of high-quality data collection for the purpose of hypothesis testing. The second part is self-contained and nontechnical and describes complete plans for a site-specific checklist survey, suitable for addressing monitoring questions frequently asked by amateurs and for involvement of volunteers in data collection. Throughout are references to additional resources, from background literature to sources of existing survey protocols, analysis software, and tools for archiving data.

Monitoring Bird Populations by Point Counts

Monitoring Bird Populations by Point Counts
Author: C. John Ralph
Publisher: Wildlife Research Group
Total Pages: 0
Release: 1998
Genre:
ISBN: 9780899046518

Point counts of birds are the most widely used quantitative method and involve an observer recording birds from a single point for a standardized time period. In response to the need for standardization of methods to monitor bird populations by census, researchers met to present data from various investigations working under a wide variety of conditions, and to examine various aspects of point count methodology. Statistical aspects of sampling and analysis were discussed and applied to the objectives of point counts. The final chapter presents these standards and their applications to point count methodology.