Malakofauna v nivě Jizery (Severní Čechy) [The mollusc fauna of the Jizera River floodplain (North Bohemia)

Abstract

This paper presents a research of floodplain mollusc communities of the Jizera River (the Elbe tributary, North Bohemia, Czech Republic). Altogether, 101 mollusc species (100 species of gastropods, one species of bivalve) were recorded at 55 selected sites during previous and recent researches in 1945–1997 and 2002–2009, representing 40% of the total Czech malacofauna. The upper well-preserved stretch of the river hosts a rich forest mollusc fauna with some rare woodland species e.g. Arion intermedius, Cochlodina dubiosa corcontica, Daudebardia brevipes, D. rufa, Vertigo alpestris and Vitrea subrimata. Impoverish assemblages of the lower stretch are represented by some common or open/semi-open country species, because the river flows there through the landscape of an intensive agricultural land use and high settlement density. Despite, the occurrence of 31 rare species (four of them endangered, eight vulnerable, and 19 near threatened) was recorded at the upper stretch of the Jizera River alluvium, which provides an important refuge for these mollusc faunas.