Woodland mollusc communities along environmental gradients in the East Carpathians

Abstract

Mollusc communities were sampled quantitatively at eleven sites representing different environmental conditions in the Bieszczady National Park (East Carpathians Mts, Poland). Overall 61 species were recorded. Alder forest in the valleys (AF; Alnetum incanae carpathicum, Caltho-Alnetum, secondary alder forest) hosted the richest fauna, with up to 41 species occurring sympatrically on 100 m 2 of forest floor and average density ca. 750 specimens m −2 . Three important ecological controllers of species composition and community structure were found. The main predictor of mollusc assemblage composition was calcium content; the first DCA axis of molluscs most significantly and highly correlated with calcium content in the leaf litter and organic matter in the upper layer. The second axis significantly correlated with altitude and negatively with annual temperature, and thus can be explained as an elevational gradient. We observed slope aspect to constitute the third significant gradient. On the basis of forward selection in CCA analysis organic matter in the upper layer of soil was the best predictor of species composition, which explained 26% of total variance. It comes to prove that in mountain forest on non-calcareous bedrock molluscs obtain calcium mainly from leaf litter.

River Floodplains as Habitat and Bio-Corridors for Distribution of Land Snails: Their Past and Present

“…The vegetation structure and species composition control for example micro-climatic site conditions for gastropods (Boycott, 1934;Cameron et al, 1980, Labaune & Magnin, 2001Čejka et al, 2008;Dvořáková & Horsák, 2012 etc. ), the amount and quality of food sources (Horsák et al, 2010), sufficiency of suitable shelters (Horsák et al, 2013b) or the amount and quality of leaf litter (Sulikowska-Drozd & Horsák, 2007;Čejka et al, 2008) all of them directly influencing snail assemblages.…”

The occurrence of protected vertiginids Vertigo angustior Jeffreys, 1830 and V. moulinsiana (Dupuy, 1849) (Gastropoda: Pulmonata: Vertiginidae) in the estuary of the Odra River

“…The phytoindication method was applied for the purpose of statistical analyses, using ecological index numbers proposed by zArzycki et al (2002) (L -light value, W -soil moisture value, T -trophy value, R -soil acidity (pH) value, H -organic matter content value). Plant indicator values had been successfully used previously as a tool for land mollusc autecology assessment (horsák et al , sulikowskA-DrozD & horsák 2007.…”

Local and regional scale biodiversity patterns of forest snail assemblages in Tuscany (central Italy)

“…On the contrary, Valovirta (1968) and Juřičková et al (2008) recorded lower species numbers in acid plots. Calcium-rich sites (that usually have high pH) are in general richer both in number of individuals and species , Martin and Sommer 2004, Horsák 2006, Sulikowska-Drozd and Horsák 2007, Juřičková et al 2008, thus pH would also be expected to influence species richness in limestone sites. In our case, however, even plots on calcareous substrates had slightly acid pH (never higher than 6.71) and this parameter is probably not closely correlated with the amount of calcium.…”

“…Forests of the Mediterranean basin are particularly sensitive to climate change effects, especially increased temperatures, modified rainfall patterns and soil properties (Resco de Dios et al 2007), factors that can negatively affect the local survival of snails (Pearce and Paustian 2013); thus, describing their biocoenoses can provide valuable insights in monitoring and prevention programs, especially in protected areas. Ecological factors that shape terrestrial snail assemblages have been investigated in central and northern Europe for decades, focusing on single or combinations of environmental parameters (Valovirta 1968, Evans 1972, Martin and Sommer 2004, Horsák 2006, Kappes et al 2006, Sulikowska-Drozd and Horsák 2007, among others) but such studies are almost completely lacking for Italian land snails (Giusti et al 2005), except for a paper on acid woodland in the southern Alps (Bishop 1980). …”

“…Ecological factors that shape terrestrial snail assemblages have been investigated in central and northern Europe for decades, focusing on single or combinations of environmental parameters (Valovirta 1968, Evans 1972, Martin and Sommer 2004, Horsák 2006, Kappes et al 2006, Sulikowska-Drozd and Horsák 2007 but such studies are almost completely lacking for Italian land snails (Giusti et al 2005), except for a paper on acid woodland in the southern Alps (Bishop 1980).…”