Temperature and predators as interactive drivers of community properties

Area of Science:

• Ecology
• Environmental Science
• Microbiology

Background:

• Ecological community responses to warming are complex, influenced by individual physiology and predator-prey dynamics.
• Understanding these responses is challenging due to the difficulty in linking micro-level mechanisms to macro-level community patterns.
• Changes in predator populations can interact with temperature shifts, further altering community structure.

Purpose of the Study:

• To investigate the combined effects of warming and predation on ecological communities.
• To test generalized predictions about how warming influences community diversity, body size, function, and composition.
• To assess the role of predator-prey interactions in mediating temperature-driven community changes.

Main Methods:

• A factorial experiment manipulating temperature and the presence of the predator *Actinosphaerium*.
• Utilized microcosms containing a diverse assemblage of protists, rotifers, and a gastrotrich.
• Measured changes in community respiration, predator:prey biovolume ratios, species richness, body size, and overall biomass.

Main Results:

• Community respiration and predator:prey biovolume ratios peaked at intermediate temperatures.
• Species richness exhibited a decline with increasing temperature.
• Overall biomass increased with species richness, demonstrating an indirect effect of temperature on biomass via richness.

Conclusions:

• Predicting general ecological community responses to warming remains challenging.
• Temperature significantly impacts community structure, particularly species richness and biomass.
• The interaction between warming and predation was limited, with the predator's distribution influenced by temperature.