Population–reaction model and microbial experimental ecosystems for understanding hierarchical dynamics of ecosystems

Kazufumi Hosoda,Soichiro Tsuda,Kohmei Kadowaki,Yutaka Nakamura,Tadashi Nakano,Kojiro Ishii

doi:10.1016/j.biosystems.2015.12.005

Kazufumi Hosoda, Soichiro Tsuda + Show 4 more

Open Access

https://doi.org/10.1016/j.biosystems.2015.12.005

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Abstract

Understanding ecosystem dynamics is crucial as contemporary human societies face ecosystem degradation. One of the challenges that needs to be recognized is the complex hierarchical dynamics. Conventional dynamic models in ecology often represent only the population level and have yet to include the dynamics of the sub-organism level, which makes an ecosystem a complex adaptive system that shows characteristic behaviors such as resilience and regime shifts. The neglect of the sub-organism level in the conventional dynamic models would be because integrating multiple hierarchical levels makes the models unnecessarily complex unless supporting experimental data are present. Now that large amounts of molecular and ecological data are increasingly accessible in microbial experimental ecosystems, it is worthwhile to tackle the questions of their complex hierarchical dynamics. Here, we propose an approach that combines microbial experimental ecosystems and a hierarchical dynamic model named population–reaction model. We present a simple microbial experimental ecosystem as an example and show how the system can be analyzed by a population–reaction model. We also show that population–reaction models can be applied to various ecological concepts, such as predator–prey interactions, climate change, evolution, and stability of diversity. Our approach will reveal a path to the general understanding of various ecosystems and organisms.

Highlights

Understanding ecosystem dynamics is crucial in view of the recent degradation of ecosystem services, which support human life (World Resources Institute, 2005); we have yet to understand the features of ecosystem dynamics, i.e., how ecosystems have been organized, sustained, and degraded
We presented a strategy for understanding ecosystem dynamics with phenotypic change using microbial experimental ecosystems (MEEs) and population–reaction model (PRM)
It is easy to add other concepts such as spatial structure in a conventional way in either field of population ecology or reaction kinetics because the PRM is a fusion of conventional models in those fields

Summary

Introduction

Understanding ecosystem dynamics is crucial in view of the recent degradation of ecosystem services, which support human life (World Resources Institute, 2005); we have yet to understand the features of ecosystem dynamics, i.e., how ecosystems have been organized, sustained, and degraded. A phenotype can be considered as an interface between two hierarchical levels in ecosystems: the ecological level, composed of various organisms and environmental. To understand how ecosystems change, it is necessary to consider the phenotypic changes that determine and are determined by the interaction between two hierarchical levels (Conrad, 1996; Conrad and Pattee, 1970). In this perspective, we focus on the hierarchy of ecosystems, a core feature that makes ecosystems complex adaptive systems (Levin, 1998) that bring important features such as resilience and regime shifts. We describe key challenges, our proposed approach, and examples of PRMs

Challenges

Proposed approach

A simple example of a population–reaction model with experimental data

Findings

Conclusion