Influència de l\'altitud en la riquesa d\'especies de mol·luscs: variacions a la vall d\'Alinyà, Alt Urgell

Influence of elevation on the species richness in molluscs: variations in the Alinyà valley, Lleida (Northeast Spain).— The species richness of land molluscs is negatively correlated with altitude, while the altitudinal range of the species inhabiting at higher elevations is greater than in low levels. At the low scale of this study factors other than elevation may account better for the species richness.