Strain-specific functional and numerical responses are required to evaluate impacts on predator-prey dynamics

Area of Science:

• Ecology
• Population Dynamics
• Microbial Ecology

Background:

• Protozoan ingestion and growth rates are influenced by temperature.
• Inter-strain variability in these rates can affect population dynamics.
• Understanding these factors is crucial for ecological modeling.

Purpose of the Study:

• To investigate how inter-strain variation in protozoan ingestion and growth rates influences population dynamics and intraspecific competition.
• To assess the impact of temperature on these variations.
• To compare standard modeling approaches with a novel framework incorporating independent functional and numerical responses.

Main Methods:

• Establishing laboratory cultures from field-collected protozoan strains.
• Measuring inter-strain variability in thermal sensitivity of maximum growth rate.
• Parameterizing the influence of temperature on functional and numerical responses of representative strains.
• Assessing predator-prey population dynamics using standard and novel modeling frameworks.

Main Results:

• Significant inter-strain variability in the thermal sensitivity of maximum growth rate was observed in Oxyrrhis marina.
• Distinct differences in thermal responses were identified among multiple strains.
• A novel framework incorporating independent functional and numerical responses provided a more realistic account of predator-prey dynamics compared to standard approaches.

Conclusions:

• Including functional diversity at the sub-species level alters ecological model predictions.
• Directly measured, independent functional and numerical responses enhance the realism of predator-prey dynamics models.
• Temperature significantly influences protozoan functional and numerical responses, impacting population dynamics.