Population Density and Patch Size: A Field Study of within and between Generation Variability

By Matter, Stephen F. | The American Midland Naturalist, January 2007 | Go to article overview

Population Density and Patch Size: A Field Study of within and between Generation Variability


Matter, Stephen F., The American Midland Naturalist


ABSTRACT.-

How population density scales with habitat area is an important consideration for spatial population dynamics and community patterns. I examined the relationship between local population density and habitat area for an herbivorous beede Tetraopes tetraophthalmus (Forster) inhabiting patches of its host plant Asclepias syriaca L. Field observations over 4 y (1992, 1995-97) at the same site revealed that the relationship was variable during the adult fight season. Highest densities occurred on large patches early in the season, but as the season progressed, densities tended to equilibrate among patches of various sizes. Among years the relationship also showed considerable variability, but similar within generation patterns. Considering entire generations, increasing, decreasing and constant density with patch size were observed over the four years of observation. The results of this study indicate that there is considerable within and between generation variability in the density-area relationship. How population density varies with habitat area affects conservation reserve design and underlies spatial population and community theory. Variability in density-area relationships will introduce greater uncertainty for predictions of metapopulation persistence as well as estimates of community structure. Given the degree of variability seen in this system, any single estimate of a density-area relationship would be misleading. Multiple estimates, taken both within and between generations, should be performed before applying density-area relationships in studies of spatial population dynamics, community patterns and reserve design.

INTRODUCTION

A basic area of inquiry for spatially segregated populations is how local population density varies with habitat area. This relationship, called the individuals-area relationship (Schoener, 1986) or the density-area relationship, underlies ecological dieory (MacArthur and Wilson, 1967; MacArdiur et aL, 1972; Schoener, 1986; Hanski, 1994; Connor el aL, 2000; Matter, 2000) and is pertinent to conservation issues (Haila, 1988; Simberloff, 1988; Andren, 1994; Hanski, 1994; Connor et aL, 2000; Gaston and Matter, 2001) and pest control (Root, 1973; Denno et al, 1981; Kareiva, 1983). How population density varies with habitat area affects single-species population and metapopulation dynamics. Within a network of populations, increasing or decreasing density with area clusters individuals into large or small patches, respectively. This clustering of individuals changes the impact of density-dependent processes and the relative importance of different sized patches for spatial population dynamics and persistence (Hanski, 1994; Matter, 2000; 2001a). Similarly, local populations of the same size, but within networks of patches with different density-area relationships can show different dynamics (Matter, 1999; 2001a). Clustering of individuals into large or small patches can also affect community-level patterns, such as the species-area relationship and nestedness, which assume that die population density of component species does not vary with site area (Connor et aL, 2000; Matter, 2000).

Density-area relationships have been considered a species specific trait, resulting from social or behavioral constraints or patch size dependent dispersal patterns specific to a species (Connor et aL, 2000). Lending credence to diis belief, examinations of densityarea relationships generally have found consistency, at least in terms of sign, for species for which multiple estimates have been made (Bowers and Matter, 1997; Connor et aL, 2000). Relatively litde attention has been given to variability in the relationship. Examining and understanding this variability is critical if density-area relationships are to be of any practical use. For example, metapopulation models assume that the risk of population extinction decreases with increasing population abundance. To limit the amount of data needed, population abundance is often assumed to increase with habitat area and extinction risk is then related to habitat area dirough an exponential relationship, radier than directly to population abundance (Hanski, 1994). …

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Population Density and Patch Size: A Field Study of within and between Generation Variability
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.