Modelling temperature-driven changes in species associations across freshwater communities

Area of Science:

• Ecology
• Climate Change Biology
• Freshwater Ecology

Background:

• Global climate change causes shifts in species distributions, necessitating tools to predict community composition changes.
• Understanding how species associations change along environmental gradients is crucial for predicting future distribution shifts, especially in connectivity-limited freshwater ecosystems.
• Human activities are introducing new species associations across novel environmental gradients in freshwater systems.

Purpose of the Study:

• To investigate the impact of temperature on species associations in freshwater fish communities.
• To utilize a Joint Species Distribution Model (JSDM) to analyze large-scale presence-absence data.
• To identify shifts in species associations driven by temperature gradients in the Fennoscandian region.

Main Methods:

• Employed a Joint Species Distribution Model (JSDM).
• Analyzed a large-scale presence-absence dataset of freshwater fish from lakes in the Fennoscandian region.
• Quantified the effect of local temperatures on species associations.

Main Results:

• Observed negative associations between cold-water tolerant and warm-water tolerant species.
• Identified positive associations among several warm-tolerant species.
• Found that species associations shifted in response to local temperature variations.

Conclusions:

• Freshwater ecosystems are projected to experience a significant shift towards communities dominated by warm-tolerant species.
• The JSDM provides a foundational approach for exploring climate-driven community trends and identifying vulnerable areas.
• Further research is needed to predict precise locations and timing of local extinctions.