Precipitation and temperature drive continental-scale patterns in stream invertebrate production

Area of Science:

• Ecology
• Environmental Science
• Climate Change Research

Background:

• Secondary production, the creation of new heterotrophic biomass, is a fundamental ecological process in aquatic and terrestrial ecosystems.
• Understanding factors influencing secondary production is crucial for ecosystem health assessment and management, particularly in flowing water environments.

Purpose of the Study:

• To investigate the primary pathways linking climate variables (air temperature, precipitation) to the secondary production of stream invertebrate communities globally.
• To assess the impact of climate change on secondary production using a comprehensive dataset and advanced modeling techniques.

Main Methods:

• Utilized structural equation modeling (SEM) to analyze the first worldwide dataset on annual secondary production of stream invertebrate communities.
• Examined relationships between climate covariates and secondary production across various spatial scales, including the United States, Europe, Central America, and the Pacific.

Main Results:

• In the United States, precipitation-driven low-stream flow events were found to have a significant negative impact on secondary production.
• Across larger geographical scales, a positive two-step pathway was identified, where increased air temperature leads to warmer water temperatures, subsequently increasing secondary production.

Conclusions:

• The study elucidates critical climate-driven mechanisms affecting secondary production in stream ecosystems.
• The findings offer valuable insights into the potential consequences of climate change on aquatic ecosystems and provide a flexible modeling framework applicable to diverse environments.