Research and analysis

Understanding ecosystem dynamics using ecological network analysis: summary

Published 16 December 2024

Applies to England

1. Chief Scientist’s Group report summary

This project explored whether ecological network science could help the Environment Agency understand the role microbial communities play in English river ecosystems. Ecological network science considers interactions between organisms and the resulting networks that form. Recommendations from three leading academics describe how this approach could help determine how microbial communities are structured and how species interact with each other. This has potential to improve our understanding of how ecosystems function. However, challenges must be overcome for it to be used in practice.

1.1 Background

Microbial communities include bacteria, diatoms, fungi, and other single celled microscopic organisms. They play important roles in ecosystems, including cycling of nutrients such as nitrogen and carbon, and breaking down of harmful pollutants. The development of new technologies that analyse genetic material in the environment is already improving understanding of the dynamics of microbial communities and the roles they play in ecosystems. Ecological network science could allow the exploration of how these interactions change over time under different environmental conditions, providing information on species that have important roles in ecosystems.

1.2 Approach

The project explored ecological network science and provides recommendations about applying this approach to a large microbial dataset generated from river biofilms (an aggregate of microbes found on moist surfaces) that were collected as part of a new Environment Agency monitoring programme.

1.3 Results

The leading academics highlight that microbial interactions need to be inferred because these interactions cannot be observed as they can be with larger organisms. Different methods to infer interactions and construct networks are identified. The authors agree that a range of different methods could usefully be tested on the dataset. An advantage of taking an ecological network approach is that it can combine and analyse data about different groups and types of organisms. Genetic information about the nutrients an organism can use and the pollutants they can transform can also be included.

The report describes methods that explore how microbial networks respond to perturbations in environmental conditions through time. More conventional statistical techniques can be used alongside network analysis to explore relationships between microbial communities and changes in the physical environment. Other interesting avenues to explore include the use of network analysis to identify microbial species that play an important role in a community and therefore help ecosystems to function.

Network analysis could also be used to describe how resilient an ecosystem is to extinction events by assessing the impact of one species being removed from the network on the wider ecosystem. One author describes microbial network science as being ‘in its infancy’ and advises caution if using this approach as it has not yet been extensively applied to aquatic ecosystems.

The authors identify knowledge gaps in our ability to link the outputs of network analysis to real-world attributes of how ecosystems function and their stability to environmental change. They also highlighted challenges in using network analysis techniques, such as the need for high computing power.

1.4 Conclusions

This report highlights that despite challenges, ecological network analysis could improve the understanding of the dynamics of microbial communities and their role in river ecosystems and that the Environment Agency’s microbial dataset presents an exciting opportunity to test this approach.

1.5 Publication details

This summary relates to information from the following project:

• Title: Understanding ecosystem dynamics using ecological network analysis
• Project manager: Kerry Walsh, Chief Scientist’s Group

This project was commissioned by the Environment Agency’s Chief Scientist’s Group, which provides scientific knowledge, tools and techniques to enable us to protect and manage the environment as effectively as possible.

Enquiries: [email protected].

© Environment Agency