Transects, Quadrats, and Other Sampling Units

Steven N. Murray, Richard F. Ambrose and Megan N. Dethier

in Monitoring Rocky Shores

Published by University of California Press

Published in print March 2006 | ISBN: 9780520247284
Published online March 2012 | e-ISBN: 9780520932715 | DOI:
Transects, Quadrats, and Other Sampling Units

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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.

Keywords: sampling; sampling units; intertidal zone; line transects; quadrats; species abundances; plotless methods; intertidal habitats; tidepools; boulder fields

Chapter.  8897 words.  Illustrated.

Subjects: Animal Pathology and Diseases

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