# Modeling Trophic Dynamics in Lake Võrtsjärv: Energy Flow and Species Interactions

## TL;DR

This paper develops a trophic network model for Lake Võrtsjärv to study predator-prey relationships and energy flow, using empirical data to improve model accuracy.

## Contribution

The study introduces a calibrated trophic network model for a lake ecosystem using numerical optimization methods with more complex parameters than prior models.

## Key findings

- The model achieved 77%–81% similarity between modeled and recorded biomass dynamics.
- Models incorporating noise could not realistically describe annual biomass variation.
- Calibrating complex bioenergetic models to empirical data remains challenging despite high similarity.

## Abstract

Understanding ecosystem dynamics is essential for ecological research and resource management. Bioenergetic or allometric trophic network models are effective in elucidating these interactions. However, aligning them accurately with empirical data remains challenging. Our present study contributes to such efforts by developing a trophic network model to describe population dynamics at Lake Võrtsjärv, Estonia, with a focus on predator–prey relationships and energy considerations. We calibrate this model to empirical biomass time series data using numerical optimization methods, a process previously applied to bionergetic models with considerably fewer guilds and/or parameters. Our approach emphasizes aligning the model closely with empirical time series and yields 77%–81% similarity between the modeled average dynamics and recorded biomasses. Despite relatively high similarity, the models we tested for noise—those assuming observation noise, as well as those incorporating environmental noise through stochastic differential equations—could not describe the annual variation of biomasses realistically. Overall, our tentative results demonstrate both the potential and the challenges involved in calibrating bioenergetic models to empirical data from large food webs.

Aligning bioenergetic, or allometric trophic network, models accurately with empirical data remains challenging. Our present study contributes to these efforts by developing a trophic network model to describe population dynamics at Lake Võrtsjärv, Estonia, with a focus on predator–prey relationships and energy considerations. We calibrate this model to empirical biomass time series data using numerical optimization methods, an approach previously applied to bionergetic models with considerably fewer guilds and/or parameters.