Small-scale spatial variation of pasture molluscan faunas within a relic watermeadow system at Wylye, Wiltshire, U.K.
Aim To acquire general quantitative data on the molluscan faunas of floodplain pastures, assessing the influence of (minor) topographic variation on molluscan distribution. Additionally, to examine the potential for analogous comparison with fossil data
Location The study was located within a relic watermeadow system currently used as floodplain pasture near Wylye, Wiltshire, U.K.
Methods Mollusca were extracted from forty turf samples collected from relic carriers (cf. ridges) and relic drains (cf. furrows). Molluscan faunal differences between carriers and drains were assessed usingTWINSPANand diversity indices.
Results The dry relic carriers, characterized by a short grassy sward, showed a low-diversity Trichia-Vallonia-Cochlicopa-Nesovitrea fauna. The damper relic drains, characterized by longer vegetation comprising both rushes and grasses, additionally contained other molluscan species indicative of wetter and/or more sheltered conditions and had significantly more diverse faunas
Main conclusions Intra-site variability of molluscan faunas can be demonstrated with relatively minor changes in topography, hydrology and/or vegetation structure. In addition, the study clearly aids in the analogous interpretation of Holocene subfossil assemblages from the same region.
Document Type: Original Article
Publication date: 1999-09-01