NadpisLocal Diversity Versus Geographical Distribution of Arthropods Occuring In A Sandstone Rock Labyrinth
Publication TypeJournal Article
Year of Publication2010
AutořiRuzicka, V, Mlejnek, R, Smilauer, P
JournalPolish Journal of Ecology

Rocks have been overlooked as subjects for ecological study. However, the system of narrow and deep vertical spaces (gorges, crevices, abysses) in sandstone rocks supports a highly diverse mosaic of habitats. The patterns of air temperatures and the assemblages of arthropods were studied along the environmental gradient in the Poseidon Sandstone Labyrinth within the Adrspassko-Teplicke Skaly National Nature Reserve, NE Bohemia, Czech Republic. The labyrinth, developed in Cretaceous sandsones at an altitude of about 600 m, is approximately 740 m long and 550 m wide. It consists of a broken, interconnected network of deep vertical crevices, crevice caves, and talus caves in extensive block accumulations. The total length of the human-accessible underground spaces is estimated to be at least 27 km, the vertical range is 105 m. The annual course of air temperature was monitored on the sun-exposed upper rock margin (max. 26.5 degrees C, mm. -7.3 degrees C, mean 6.1 degrees C), as well as in the cold and dark crevice cave (max. 9.6 degrees C, min. -1.9 degrees C, mean 3.7 degrees C). Due to the climatic inversion in the deep vertical spaces, mountain bryophytes and vascular plants occur here. A total of 2285 arthropods belonging to eight taxonomic groups were evaluated; spiders and beetles were the most numerous. We registered 304 species, which colonize the totality of habitats in the labyrinth: cold bottom parts, dark caves, shady rock walls, as well as the sun-exposed upper rock margins. The cold parts of the labyrinth harbour populations of sixteen species of mountain arthropods (beetles, spiders and a harvestman) and five species of arthropods with distributions in tundra or boreal forests, and similar disjunctive habitats in the temperate zone in central Europe (spiders and a mite). The first record of the Arctic predatory mite Rhagidia gelida in central Europe was in the Poseidon Labyrinth in 1986; this species proved to be a bio-indicator of the long-lasting periglacial microclimate in central Europe. Prior to discovery of the spider Sisicus apertus in the Poseidon Labyrinth, it had been recorded in central Europe in the Alps and in the High Tatra Mountains at altitudes of 1150 to 2300 m. At the present time, we consider the Poseidon Sandstone Labyrinth to be a paleorefugium of cold-adapted arthropods.