Antwerps Spinnenonderzoeksproject
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THE ANTWERP SPIDER RESEARCH PROJECT (ASOP)

Surprising observations serve ecological management of urban green spots

Between September 2004 and October 2005, the first phase of a study of the spider fauna of Antwerp's inner city area was completed. Antwerp is the largest city in the north of Belgium. In the west it is bordered by the 400 meter wide river Scheldt, and the other sides by the ringway around the city. The oldest part is situated near the river. From there the city expands in concentric circles. During the first phase only the Sixteenth Century city area (marked in red) was examined. This research was noticed internationally by the press and the scientific community because of the surprising results in more than one area. The second phase (area marked in black) was started in april 2006 and runs upto april 2008. The results will be used to advise the Antwerp city council on ecological management of city green spots.
 


Antwerp: marked in red, the first phase area. Marked in black the investigated area of phase two.

 

SPIDERS IN THE CITY

What is the importance of spiders in a city?

City areas are by definition densely populated. This creates an enormous pressure on the environment since people produce huge amounts of waste and tend to extremely manipulate their habitat according to their needs. A number of plant and animal species has adapted perfectly to this biotope. We know that some rat or mouse species e.g. would never have been so numerous and widespread if it were not for cities. Quite a number of insect species which live mainly in human environments, thrive especially in urban areas. In our part of the world, cockroaches will seldom be found in the countryside, let alone in large numbers. This is due to unfavourable or too isolated biotope, but more importantly because of a lack of frequent introduction of these exotic animals in rural areas. Cities know a more extended traffic of people and goods. Although any one of these animals has its "use" for the ecosystem and is often dilligently doing away with our waste, they are considered pests when they grow too numerous and/or start spreading diseases among people. Luckily, there is also a number of spider species which has adapted perfectly to a human environment. They are often the ones preventing population explosions in these "pest insects" through predation.

Increasing attention

The amount of urban surface, as well as the amount of people living there, increases enormously worldwide. At this very moment, already more than half the human population is living in urban areas. For this reason and because the ecology of this biotope influences importantly the living conditions of humans, the study of urban ecology has become more important since the 1980s. Nevertheless, this study is still neglected at many universities and that's why the spider species composition of urban areas is little worked upon untill today. There have been carried out some extensive studies, mainly in German speaking Europe, but these revealed little about the specificity of a spider fauna in strongly urbanized areas. This is a consequence of the choice which was made to include the larger green zones around cities in the faunistic inventory and to make little distinction between the faunas of urban subhabitats.

Unique project

The Antwerp Spider Research Project (ASOP, in Dutch) wants to stop this gap by providing for the first time a detailed image of the spider fauna of a strongly urbanized area with some important subhabitats like parks, railway grounds, city gardens, sewer systems and buildings. To be able to produce representative results, sampling must be thorough. The catching of spiders through different sampling methods (see "Werkwijze" in the menu) is labour-intensive. Meanwhile, a group of researchers from the Ghent University has started up a similar study in the city of Ghent. It is expected that a comparison between the results of both studies will lead to interesting finds.

Surprisingly large species diversity in the city

108 different spider species were found in the inner city of Antwerp. After nine months of sampling in the "second city belt", we are at 205 species! For the species list, look at Resultaten. The spider fauna of Flanders (northern part of Belgium) includes about 600 species, and more than 1/3 of it is represented in the strongly urbanized part of Antwerp. More than 30 species appear on the red list of rare or endangered spiders in Flanders. At this moment, we already found 3 (probably 4) new species to Belgium.
 


Some typical urban 'green spots' of the Antwerp inner city: tiny habitats harbouring a surprising spider species diversity.

Conclusion

After more than two years of sampling, certain tendencies are starting to show, but already it is clear that there are so many aspects to this research that the deadline of june 2008 will leave us with lots of uncertainties and unanswered questions. However, a number of substantiated insights will just as well be acquired. Already there is an international interest in the final results of the Antwerp Spider Research Project. These results will also be presented on the 24th European Colloquium of Arachnology in 2008, that will be held in Switserland.

For more information, contact the coordinator of the Antwerp Spider Research Project (ASOP, Antwerps Spinnenonderzoeksproject): Koen Van Keer
 


  
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