SPIDERS ON THE FURKA
The Department of Botany at the University of Basel runs a research station, ALPFOR, in the region of the Furka Pass. In 2012, the department invited biologists of various disciplines to conduct a biodiversity assessment. In this context spiders were collected by hand picking and with traps. Out of this short term assessment a research project emerged lasting for several years.
Little is known about the alpine spider fauna in Switzerland, and so the Furka data is of great interest. We surveyed various types of alpine meadows, catching spiders with pitfall traps and hand collecting. Differences between the locations were considerable, especially between west and east-exposed meadows.
In the following years, the investigations continued at a few sites, so that fluctuations over time could be documented. Depending on weather patterns, the appearance of individual species can change by as much as one month.
In 2014, collection activity concentrated on levels between 2,200 and 2,600 metres. Two transects, one on a west- the other on an east-facing slope, resulted in a clear data-difference depending on the height of the location.
As a result of these preliminary tests, the master thesis of David Raaflaub was implemented. The aim was to find out whether the large-scale differences also occur on a small scale as a function of exposure. Corresponding to the exposure of the traps set up over small soil ridges (moraines), similar differences were found over a few meters as on the previously examined slopes.