Factors Influencing the Distribution of Freshwater Mollusks in the Lakes of the Pyrenees: Implications in a Shifting Climate Scenario

• Published in: Diversity (Basel) Vol. 15; no. 4; p. 500
• Main Authors: de Mendoza, Guillermo, Araujo, Rafael, Catalan, Jordi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-04-2023
• Subjects: acid neutralizing capacity; Altitude; Aquatic plants; Chemistry; Climate; Climate change; climate warming; Climatic changes; Environmental aspects; Fresh water; Freshwater lakes; Freshwater mollusks; Generalized linear models; Genetic aspects; Global warming; Growth; Lakes; Lithology; Mollusca; Mollusks; mountain lakes; Mountain regions; Mountainous areas; Mountains; Numerical analysis; Pisidium; Skewness; Software; Substrates; Surface temperature; Taxonomy; Thermal response; upward distributional shift; Variables; Spain
• ISSN: 1424-2818; 1424-2818
• DOI: 10.3390/d15040500

Climate warming is expected to drive an upward altitudinal shift of species distributions in mountain areas. In this study, we consider how environmental variables constrain the distribution of freshwater mollusks across elevations based on an extensive survey of the entire Pyrenean range. Results show that several altitude-related variables are significantly relevant for the distribution of all mollusks (i.e., temperature, sediment organic content). Others respond more precisely to some variables: fine substrate proportion increases the probability of finding Pisidium sensu lato (mostly Euglesa species), and the latter, the macrophyte presence, and Ampullaceana balthica. Despite the low acid-neutralizing capacity in many of the lakes, only the distribution of A. balthica was significantly constrained by this factor, independent from elevation. The results confirm a likely altitudinal expansion of the distributions of all species, particularly toward lakes with a summer surface temperature increasing above 12 °C. The pace of change is expected to differ among species according to different nonlinear thresholds in thermal response, which temperature value increases from Pisidium s.l. to Ampullaceana to Ancylus, and the taxon-specific sensitivity to substrates and chemical conditions.