The effects of catastrophic ecosystem disturbance: the residual mammals at Mount St. Helens

Journal of Mammalogy
By:  and 



Individuals that survive the direct effects of community- or ecosystem-level disturbances, i.e., "residuals", can have major roles in determining the rate and pathway of subsequent secondary succession. The explosive eruption of the Mount St. Helens volcano on 19 May 1980 resulted in severe damage to a cast array of animal and plant populations (Edwards and Schwartz, 1981; MacMahon, 1982; Hayward et al., 1982). We apply the term "catastrophic" to this event because of its intensity and the large area (>600 km2) over which successional processes were initiated.

We present here the results of surveys for mammals, particularly small mammals (excluding bats), conducted in the Mount St. Helens region during the 40 months following the eruption. Our purpose was to elucidate any patterns in species representation that might exist along a gradient of disturbance "intensity", and thus document which species could potentially influence early plant successional patterns there. We infer whether individuals captured were more likely to have been residuals (or their descendants), or immigrants from areas less affected by the eruption, from consideration of the time span between the eruption and the capture date, the trapping location, and life history data. We also make inferences concerning the animal-environment relationships that led to our survey results, and thereby address the question of the likelihood of other types of disturbance, either natural or anthropogenic, producing similar results. Data concerning survival of Thomomys talpoides, the northern pocket gopher, have been presented elsewhere (Andersen, 1982). Initial results from our studies of the relationships among residual small mammals and plant population dynamics are detailed in MacMahon and Warner (1984), Allen et al. (1984) and Andersen and MacMahon (in press).

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Publication type Article
Publication Subtype Journal Article
Title The effects of catastrophic ecosystem disturbance: the residual mammals at Mount St. Helens
Series title Journal of Mammalogy
DOI 10.2307/1380942
Volume 66
Issue 3
Year Published 1985
Language English
Publisher American Society of Mammalogists
Publisher location Provo, UT
Description 9 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Mammalogy
First page 581
Last page 589
Country United States
State Washington
Other Geospatial Mount St. Helens
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