Diversity of protists and bacteria determines predation performance and stability

Area of Science:

• Ecology
• Microbial Ecology
• Food Web Dynamics

Background:

• Predation shapes prey diversity and nutrient cycling.
• The impact of bacterial prey diversity on bacterivorous protists remains unclear.

Purpose of the Study:

• To investigate how bacterial prey richness affects protistan predator production and performance.
• To explore the role of predator identity and interactions in response to prey diversity.

Main Methods:

• Utilized 456 microcosms with varying bacterial prey mixtures and single/multiple protistan predators (Tetrahymena sp., Poterioochromonas sp., Acanthamoeba sp.).
• Quantified predator production, performance variability, and evenness under different prey richness conditions.

Main Results:

• Increased prey richness enhanced single predator production and stabilized performance by reducing variability.
• Prey richness tended to increase predator evenness in multiple predation experiments.
• Predator complementarity was identified as a key mechanism influencing predator production and prey reduction.

Conclusions:

• Bacterial prey diversity significantly impacts protistan predator performance, with effects varying by predator identity and interactions.
• The diversity at both trophic levels interactively determines protistan functioning.
• Findings have implications for understanding microbial ecosystem processes and services.