Discrete event versus continuous approach to reproduction in structured population dynamics

Area of Science:

• Ecological modeling
• Population dynamics
• Physiological modeling

Background:

• Organisms with discrete reproduction, like rotifers, pose modeling challenges.
• Understanding energy uptake and use is crucial for physiological population models.

Purpose of the Study:

• To derive and compare discrete and continuous reproduction models for rotifer populations.
• To investigate the impact of reproduction type on population dynamics under varying conditions.
• To assess model performance against experimental data.

Main Methods:

• Developed a physiologically structured population model based on individual life history.
• Formulated both discrete-event and continuous reproduction models.
• Integrated population models with food dynamics into chemostat equations.
• Numerically solved equations and fitted models to literature data.

Main Results:

• An age structure is sufficient for modeling transient population dynamics after dilution rate changes.
• The discrete reproduction model accurately captures the observed lag in egg production.
• Continuous reproduction models fail to replicate this specific experimental observation.

Conclusions:

• Discrete event reproduction models offer superior accuracy for certain population dynamic phenomena.
• Physiological structure is important for individual dynamics, but age structure suffices for population-level transients.
• Model choice significantly impacts the ability to predict population responses to environmental shifts.