6 October 2010

Paleochannels in agriculturally fragmented landscape - important refuges for the molluscan fauna

Tomáš Čejka & Peter Pišút
Within the framework of the paleoecological survey of the Danubian lowland (SW Slovakia) we carried out the malacological survey at 18 palaeomeanders (old infilled riverbeds) of the Danube and Dudváh Rivers which were treated as fragment of the former wetlands. Paleomeanders were non-forested areas in the past, and so they have been continuously still in the beginning of the 20th century. The matrix was represented by arable land with no molluscs and mowed alluvial meadows (3 study sites). In total we found 62 species of the molluscs (52 species were found as alive or as empty preserved shells – 39 species were terrestrial, 13 freshwater, rest of ten species were found only as subfossil conchs). Besides euryecious and eurytopic forest species paleomeanders provide also a refuge for other species nowadays scarce in the Danube River floodplain (Cochlicopa nitens, Vallonia enniensis, Vertigo antivertigo, Anisus vorticulus and Segmentina nitida). On the basis of the death assemblages analysis we found other recently scarce species living here in the past (Gyraulus riparius, Planorbis carinatus). Results of the survey support the main hypothesis that forested and also open paleomeanders are still important refuges for diverse relic terrestrial and freshwater molluscan fauna in the intensively utilised agricultural landscape.

Článok je možné stiahnuť tu (downloadable here - in Slovak with English abstract).

No comments: