Schnedler-Meyer Nicolas A, Andersen Tobias K
National Institute for Aquatic Resources Technical University of Denmark Lyngby Denmark.
Institute for Ecoscience Aarhus University Aarhus Denmark.
Ecol Evol. 2024 Aug 7;14(8):e70020. doi: 10.1002/ece3.70020. eCollection 2024 Aug.
Animals occupying higher trophic levels can have disproportionately large influence on ecosystem structure and functioning, owning to intricate behavioral responses to their environment, but the effects of behavioral adaptations on aquatic ecosystem dynamics are underrepresented, especially in model studies. Here, we explore how adaptive behavior of fish can affect the dynamics of aquatics ecosystems. We frame fish behavior in the context of the central trade-off between feeding and predation, calculating the optimal level of feeding determined by ambient food availability and predation risk. To explore whole-ecosystem consequences of fish behavior, we embed our behavioral model within the Water Ecosystems Tool (WET), a contemporary end-to-end aquatic ecosystem model. The principle of optimality provides a robust and mechanistic framework for representing animal behavior that is relevant for complex models, and can provide a stabilizing effect on model dynamics. The model predicts an emergent functional response similar to Holling type III, but with richer dynamics and a more rigorous theoretical foundation. We show how adaptive fish behavior works to stabilize food web dynamics compared to a control model with no optimal behavior, and how changing the strength of the underlying trade-off has profound effects on trophic control and food web structure. Furthermore, we demonstrate how including fish behavior allows for an overall more realistic response of the model system to environmental perturbation in the form of nutrient enhancement. We discuss the structuring effects of behavioral adaptations in real ecosystems, and how approaches like this one may benefit aquatic ecological modeling. Our study further highlights how a mechanistic approach based on concepts from theoretical ecology can be successfully implemented in complex operational models resulting in improved dynamics and descriptive power.
处于较高营养级的动物对生态系统结构和功能可能产生 disproportionately 大的影响，这归因于它们对环境的复杂行为反应，但行为适应对水生生态系统动态的影响在研究中未得到充分体现，尤其是在模型研究中。在这里，我们探讨鱼类的适应性行为如何影响水生生态系统的动态。我们将鱼类行为置于觅食与捕食之间的核心权衡背景下，计算由环境食物可利用性和捕食风险决定的最优觅食水平。为了探究鱼类行为对整个生态系统的影响，我们将行为模型嵌入水生态系统工具（WET）中，这是一个当代的端到端水生生态系统模型。最优性原理为表示与复杂模型相关的动物行为提供了一个强大且具机制性的框架，并且能对模型动态产生稳定作用。该模型预测出一种类似于 Holling Ⅲ型的功能反应，但具有更丰富的动态和更严谨的理论基础。我们展示了与无最优行为的对照模型相比，适应性鱼类行为如何稳定食物网动态，以及改变潜在权衡的强度如何对营养控制和食物网结构产生深远影响。此外，我们证明了纳入鱼类行为如何使模型系统对以营养增强形式出现的环境扰动做出更现实的整体反应。我们讨论了行为适应在实际生态系统中的构建作用，以及像这样的方法如何可能有益于水生生态建模。我们的研究进一步强调了基于理论生态学概念的机制性方法如何能够成功地在复杂的运行模型中实施，从而改善动态和描述能力。
