Resilience of below-ground fungal communities: a mechanistic and trait-based approach

Soil provides a home to a large number of soil organisms and provides a number of services that are underpinning human health. These include storage of carbon and nutrients, which is critical for production of food and contributes to minimising the impact of Global Warming, the provision of antibiotics often derived from soil fungi, to provide and filter water and regulate hydrological cycles. There is however increasing concern that soils are in decline and may not be able to fulfil these services to the same extent if not managed sustainably. The problem we are facing is that we currently have little understanding of how soils respond to change, how this will impact on the microbial community and how this in turn will affect services mediated by microbial life.

Our project will tackle this problem by developing for the first time a theoretical framework that links soil properties, such as the complex geometry of pores within which microbes live, with biodiversity and ecosystem functioning. We will do so by demonstrating interactions and feedbacks for soil borne fungi.

Fungi can influence nearly every process that occurs in soil. There are up to 1.5 million different species of fungi, and they can form between 55 and 89% of the biomass of microbial life in soils. They are characterised by a mycelial growth form that enables them to spread through soil pores over large distances exploring the soil environment for C whilst avoiding competitors. As they interact with the environment and competing species a complex community emerges that delivers services to mankind, such as C decomposition or sequestration. It is generally believed that the diversity of a community makes soils resilient to changes and allows it to deliver services over a wide range of environmental conditions such as wetness, drought, temperature changes, but also various management strategies including organic amendments and tillage operations. This is because various competing species fulfil similar roles and can induce feedbacks that mediate perturbations to the system.

It is therefore important that we understand how these interactions shape these communities, how they respond to perturbations and what risks they are under to be no longer capable of adapting to change. To be able to answer those questions we need to have a fundamental understanding that is currently lacking.

The project will develop such a fundamental framework that will address these questions and identify what key soil properties and fungal traits make a soil more or less resilient and indicate what management options can be put in place to manage soils to be more resilient towards physical changes, such as induced by tillage operations, or wetness and drought cycles, which are envisaged to increase in extreme due to climate change. The mathematical approach followed in this proposal will be able to explore situations beyond what is experimentally tractable and can therefore identify limits beyond which soils are at risk of losing the ability to resist consequences of environmental perturbations.

The questions addressed are at the heart of the soil security programme which seeks to address how soils function and how this functioning can be sustainably managed to enable soils to resist or adapt to perturbations such as those imposed by soil management or environmental change.

This grant will deliver new insights into what soil properties enhance diversity of fungal communities, and what fungal traits and soil properties enhance resilience to perturbation. The results will indicate how diversity in soils can be managed through altering structure (e.g. via tillage operations) or amendments of organic matter seeking potentially to aim to stimulate specific fungal traits that have been identified to increase resilience.

These outcomes are of great interest to the academic community including those involved in ecology, soil science, mathematics and complex system science, as well as to a range of stakeholders including conventional and organic farmers, conservationists, and national government departments (e.g. DEFRA). Currently it is largely unknown how we can make soils more resilient to change, and this work will offer guidelines to what extend this can be achieved, and what positive actions can be undertaken. It will also identify risks to systems approaching points of instability and decline. This offers new ways by which they manage the land and offers a science basis for policy development. Other beneficiaries include the general public, and secondary Schools in enhancing the uptake of STEM subjects by demonstrating the importance of mathematics in solving real problems.

We will engage with beneficiaries in a variety of ways.

Publications and dissemination at conferences: we will publish the innovative science in leading soil and ecological journals to maximise impact, but in addition will outlining practical applications in fact sheets for a stakeholder audience. We will disseminate results at meetings to a both researchers and stakeholders to enhance uptake and allow for input into our research plan.

Discussion with wider modelling community: one way by which we enhance impact is to ensure that the approaches and key findings can be implemented into larger scale models so that coherent approaches are followed amongst different communities. This is no trivial task and will require discussions between different groups of modellers (e.g. those working with models like ROTHC). We will initiate these discussion through face-to-face meetings early into the project where it can still affect our design.

Interaction through established consortia: We will interact with three major consortia/research initiatives. One will be the community of the Soil Security Programme where we will disseminate our results through briefings and presentations at meetings. The second one will be through our project partner in France where we can interact with complex system scientists and soil scientists addressing questions related to soil management and up-scaling. The third one is the Scottish Alliance for Geoscience Environment and Society where we will in particular interact with wider research and stakeholder community in the Society and Terrestrial C themes.

Mathematics and environmental science: our work serves as a demonstration project how complex system science can be applied to environmental problems, bringing soil science under the attention of a wider research community, e.g. physicists. It also serves as a way to explain at secondary schools the importance of mathematics to enhance uptake of STEM subjects. In the past we have worked with the Prince's Trust and other organisations to run events for school children and we will continue and extend these partnerships to reach and inspire new children

Public understanding: Finally the work will enhance public understanding of the importance of soil biodiversity and will help explain how this relates to soil functioning. We will use our experience in interactive visual media to communicate complex environmental problems. These include 3D visual outputs of internal structures of soils and how microbial interactions belowground.