Response of spider communities to a large scale bark beetle infestation

The Aim of the study was to test the hypothesis that the average niche position of spider communities is changing due to openings in the forest through a large scaled bark beetle infestation. The average niche position was divided into the mean shading position and the mean moisture position on a plot, which were predicted to move towards brightness and towards humidity.

Study site
Both samplings were situated in the Bavarian Forest, a national park in the southeast of Germany. In the 1990s a large outbreak of bark beetle began, and as nothing was done against it, big openings emerged. Spider sampling was conducted in affected as well as in non affected areas, and in mountain mixed forest as well as in highmountainous pure spruce stands.
I used two studies: one from 1991 and one from 2005. Within these it was sampled with pitfall traps on a total of 150 plots. 186 spider species were caught, and the average shading and moisture position of the spider communities on the plots were determined. A canonical correspondence analysis and a linear model were used to find the factors with most effect on the species composition.

Copyright: © Eigenbeiträge der Autoren
Quelle: Jahrgang 2010 (Dezember 2010)
Seiten: 33
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Autor: Malkin Saar

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