Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0006
- Subject:
- Biology, Ecology
Most rocky intertidal zone field studies require quantification of abundance, of either individual species or other taxonomic units of the investigator's choice. Data indicating species abundances ...
More
Most rocky intertidal zone field studies require quantification of abundance, of either individual species or other taxonomic units of the investigator's choice. Data indicating species abundances can be collected quickly using subjective scales or by determining the presence of species in defined sampling units. This chapter reviews various methods of quantifying the density and cover of rocky intertidal populations using nondestructive sampling procedures. It discusses procedures used to collect abundance data during rapid surveys and while using plotless and line transect sampling methods. It focuses on plot- or quadrat-based methods for determining density and cover of intertidal macroalgae and macroinvertebrates. Differences between plots and quadrats are somewhat semantic and the terms are used as functional synonyms in this chapter.Less
Most rocky intertidal zone field studies require quantification of abundance, of either individual species or other taxonomic units of the investigator's choice. Data indicating species abundances can be collected quickly using subjective scales or by determining the presence of species in defined sampling units. This chapter reviews various methods of quantifying the density and cover of rocky intertidal populations using nondestructive sampling procedures. It discusses procedures used to collect abundance data during rapid surveys and while using plotless and line transect sampling methods. It focuses on plot- or quadrat-based methods for determining density and cover of intertidal macroalgae and macroinvertebrates. Differences between plots and quadrats are somewhat semantic and the terms are used as functional synonyms in this chapter.
Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0003
- Subject:
- Biology, Ecology
The biological units targeted by a sampling program can vary from individual-based parameters such as the size of a particular limpet species' gonads, to population-level parameters such as counts of ...
More
The biological units targeted by a sampling program can vary from individual-based parameters such as the size of a particular limpet species' gonads, to population-level parameters such as counts of all macroscopic organisms, to higher taxonomic units such as the numbers of phyla. The biological units to be selected will vary (as always) with the goals of the sampling program and with available knowledge about the ecology of the populations and communities being studied. The investigator will want to choose the most informative biological units—that is, those that best address the goals of the study and that have the potential to provide statistically powerful answers to the specific research questions. Ideally, the chosen biological units also will have known causal links with any stressors being studied. Unfortunately, clear causal relationships between stressors and responses of organisms in rocky shores are rarely known, even when only a single identifiable stressor is under consideration. Of the biological units targeted in intertidal zone monitoring, impact detection, and other research programs, the species-level population is the most commonly sampled unit.Less
The biological units targeted by a sampling program can vary from individual-based parameters such as the size of a particular limpet species' gonads, to population-level parameters such as counts of all macroscopic organisms, to higher taxonomic units such as the numbers of phyla. The biological units to be selected will vary (as always) with the goals of the sampling program and with available knowledge about the ecology of the populations and communities being studied. The investigator will want to choose the most informative biological units—that is, those that best address the goals of the study and that have the potential to provide statistically powerful answers to the specific research questions. Ideally, the chosen biological units also will have known causal links with any stressors being studied. Unfortunately, clear causal relationships between stressors and responses of organisms in rocky shores are rarely known, even when only a single identifiable stressor is under consideration. Of the biological units targeted in intertidal zone monitoring, impact detection, and other research programs, the species-level population is the most commonly sampled unit.
Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0005
- Subject:
- Biology, Ecology
A wide variety of sampling units can be used for intertidal zone field studies. The most common units include line transects and plots or quadrats. In addition, plotless designs are sometimes used. ...
More
A wide variety of sampling units can be used for intertidal zone field studies. The most common units include line transects and plots or quadrats. In addition, plotless designs are sometimes used. The choice of sampling unit depends on the goals of the sampling program, especially the species to be sampled. This chapter explains how to choose the type of sampling units in order to get accurate estimates of species abundances at a study site. Sampling can be conducted using either quadrat or plot methods or plotless methods. Plots, which are the most commonly used sampling units, are discussed first. Plotless designs, which utilize some scheme to determine which elements in the environment are sampled, are discussed next. Plotless methods have rarely been used in intertidal habitats, but they might actually be the best choice for some problematic species, such as those with large individuals occurring at low densities. Finally, sampling strategies for two intertidal habitats that provide special challenges, tidepools and boulder fields, are considered.Less
A wide variety of sampling units can be used for intertidal zone field studies. The most common units include line transects and plots or quadrats. In addition, plotless designs are sometimes used. The choice of sampling unit depends on the goals of the sampling program, especially the species to be sampled. This chapter explains how to choose the type of sampling units in order to get accurate estimates of species abundances at a study site. Sampling can be conducted using either quadrat or plot methods or plotless methods. Plots, which are the most commonly used sampling units, are discussed first. Plotless designs, which utilize some scheme to determine which elements in the environment are sampled, are discussed next. Plotless methods have rarely been used in intertidal habitats, but they might actually be the best choice for some problematic species, such as those with large individuals occurring at low densities. Finally, sampling strategies for two intertidal habitats that provide special challenges, tidepools and boulder fields, are considered.
Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0002
- Subject:
- Biology, Ecology
For any intertidal zone sampling program, site selection probably has the greatest influence on the overall program design. Unless sampling is intentionally confined to one location, and site ...
More
For any intertidal zone sampling program, site selection probably has the greatest influence on the overall program design. Unless sampling is intentionally confined to one location, and site comparisons are not needed, site selection is an important decision—one on which all conclusions obtained from the sampling program will be based. If sites to be compared are not physically similar, then physical differences can confound any conclusions about what might cause or correlate with any detected differences or trends. This chapter discusses procedures for site selection, including the classification of shorelines to avoid confounding problems resulting from differences in geophysical site characteristics. It also reviews the utility of shoreline habitat maps and the pros and cons of sampling particular microhabitats on rocky shores. In addition, it considers how sites should be selected based on program goals and how these goals will differ depending on the objectives of the sampling program. Finally, the chapter examines the key role of replicating sites in developing a robust study design.Less
For any intertidal zone sampling program, site selection probably has the greatest influence on the overall program design. Unless sampling is intentionally confined to one location, and site comparisons are not needed, site selection is an important decision—one on which all conclusions obtained from the sampling program will be based. If sites to be compared are not physically similar, then physical differences can confound any conclusions about what might cause or correlate with any detected differences or trends. This chapter discusses procedures for site selection, including the classification of shorelines to avoid confounding problems resulting from differences in geophysical site characteristics. It also reviews the utility of shoreline habitat maps and the pros and cons of sampling particular microhabitats on rocky shores. In addition, it considers how sites should be selected based on program goals and how these goals will differ depending on the objectives of the sampling program. Finally, the chapter examines the key role of replicating sites in developing a robust study design.
James T. Morris
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780195168662
- eISBN:
- 9780199790128
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195168662.003.0007
- Subject:
- Biology, Ecology
Salt marshes dominate the intertidal zone in temperate latitudes and present some unique features pertaining to measurement of primary production. Several destructive harvest and non-destructive ...
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Salt marshes dominate the intertidal zone in temperate latitudes and present some unique features pertaining to measurement of primary production. Several destructive harvest and non-destructive methods for quantifying salt marsh production are described. Allometric methods that account for stem turnover are the recommended approach. Field and laboratory procedures illustrating the recommended protocol are detailed using examples from LTER sites.Less
Salt marshes dominate the intertidal zone in temperate latitudes and present some unique features pertaining to measurement of primary production. Several destructive harvest and non-destructive methods for quantifying salt marsh production are described. Allometric methods that account for stem turnover are the recommended approach. Field and laboratory procedures illustrating the recommended protocol are detailed using examples from LTER sites.
Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0001
- Subject:
- Biology, Ecology
Field sampling programs provide the information needed to determine the status and dynamics of populations and communities and thus are the foundation for many kinds of research, including impact ...
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Field sampling programs provide the information needed to determine the status and dynamics of populations and communities and thus are the foundation for many kinds of research, including impact studies as well as monitoring studies. Certain habitat types present more formidable challenges compared with others when it comes to designing and performing field studies. The rocky intertidal zone is one of these habitat types. Unlike terrestrial habitats, the intertidal zone is accessible for most studies only during limited periods when the tide is low. The steps in designing a field sampling program include identifying the study goals, including the questions to be answered by the study or the hypotheses to be tested, and developing an effective and statistically powerful study design.Less
Field sampling programs provide the information needed to determine the status and dynamics of populations and communities and thus are the foundation for many kinds of research, including impact studies as well as monitoring studies. Certain habitat types present more formidable challenges compared with others when it comes to designing and performing field studies. The rocky intertidal zone is one of these habitat types. Unlike terrestrial habitats, the intertidal zone is accessible for most studies only during limited periods when the tide is low. The steps in designing a field sampling program include identifying the study goals, including the questions to be answered by the study or the hypotheses to be tested, and developing an effective and statistically powerful study design.
Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.003.0008
- Subject:
- Biology, Ecology
Most rocky intertidal zone monitoring and impact studies are designed to determine the status of sampled populations solely in terms of abundance. This approach can present two problems. First, ...
More
Most rocky intertidal zone monitoring and impact studies are designed to determine the status of sampled populations solely in terms of abundance. This approach can present two problems. First, abundance data alone do not adequately describe a population in a way that depicts its dynamics. Population density is a result of primary and secondary population parameters. A second problem involves the high “noise-to-signal” ratio because of the usual high variation obtained when sampling for abundance data or other population-based parameters. This chapter describes selected approaches for measuring secondary population parameters in rocky intertidal organisms. It focuses on procedures used to determine age and class size distributions, growth rates, sex or phase ratios, and reproduction in seaweeds and benthic invertebrates.Less
Most rocky intertidal zone monitoring and impact studies are designed to determine the status of sampled populations solely in terms of abundance. This approach can present two problems. First, abundance data alone do not adequately describe a population in a way that depicts its dynamics. Population density is a result of primary and secondary population parameters. A second problem involves the high “noise-to-signal” ratio because of the usual high variation obtained when sampling for abundance data or other population-based parameters. This chapter describes selected approaches for measuring secondary population parameters in rocky intertidal organisms. It focuses on procedures used to determine age and class size distributions, growth rates, sex or phase ratios, and reproduction in seaweeds and benthic invertebrates.
Steven Murray
J. Stanford and R.L. Newell (eds)
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780520247284
- eISBN:
- 9780520932715
- Item type:
- book
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520247284.001.0001
- Subject:
- Biology, Ecology
Monitoring changes in the intertidal zone of rocky shores has never been more critical. This sensitive habitat at the interface of land and ocean may well be the marine equivalent of the canary in a ...
More
Monitoring changes in the intertidal zone of rocky shores has never been more critical. This sensitive habitat at the interface of land and ocean may well be the marine equivalent of the canary in a coal mine as we advance into an era of global climate change. This book describes effective methods and procedures for monitoring the ecological and environmental status of these areas. It provides critical discussions and evaluation of the various sampling techniques and field procedures for studies of intertidal macroinvertebrates, seaweeds, and seagrasses. Rather than prescribing standard protocols or procedures, the book breaks down the decision-making process into various elements so investigators can become aware of the advantages and disadvantages of choosing a particular method or approach. Topics include site selection, field sampling layouts and designs, selection of sampling units, nondestructive and destructive methods of quantifying abundance, and methods for measuring age, growth rates, size, structure, and reproductive condition.Less
Monitoring changes in the intertidal zone of rocky shores has never been more critical. This sensitive habitat at the interface of land and ocean may well be the marine equivalent of the canary in a coal mine as we advance into an era of global climate change. This book describes effective methods and procedures for monitoring the ecological and environmental status of these areas. It provides critical discussions and evaluation of the various sampling techniques and field procedures for studies of intertidal macroinvertebrates, seaweeds, and seagrasses. Rather than prescribing standard protocols or procedures, the book breaks down the decision-making process into various elements so investigators can become aware of the advantages and disadvantages of choosing a particular method or approach. Topics include site selection, field sampling layouts and designs, selection of sampling units, nondestructive and destructive methods of quantifying abundance, and methods for measuring age, growth rates, size, structure, and reproductive condition.
