Fish and Zooplankton Co-Responses to Environmental Gradients Under Different Climate Change Scenarios.

Area of Science:

• Ecology
• Climate Change Biology
• Freshwater Science

Background:

• Climate change significantly alters freshwater ecosystems globally.
• Understanding differential impacts across trophic levels is crucial but limited.
• Few studies integrate functional and network approaches to assess community responses.

Purpose of the Study:

• To assess fish and zooplankton community responses to current and projected climate change.
• To investigate trait-environment relationships and potential species interactions.
• To evaluate climate change impacts using multiple Shared Socioeconomic Pathways (SSPs).

Main Methods:

• Joint species distribution models (JSDMs) were employed.
• Ecological network analyses were conducted.
• Trait-environment relationships were quantified for fish and zooplankton.

Main Results:

• Fish and zooplankton communities exhibited distinct responses to climate gradients.
• Fish showed stronger trait-climate relationships, with declining body size and increasing thermal tolerance.
• Freshwater communities are projected to become more homogenized by 2100 under future climate change.

Conclusions:

• Contrasting climate sensitivities exist between fish and zooplankton trophic levels.
• Climate change may lead to trophic decoupling and food web reorganization.
• Integrating trait-based and network approaches is vital for predicting freshwater ecosystem responses.