Controls on the stability of soils and their functioning under land use and climate change

Soils provide many functions for humans, including the storage of carbon and nutrient cycling, which are crucial for the production of food and mitigation of climate change. However, there is much concern that soils, and the functions that they provide, are being threatened by a range of pressures, including intensive farming methods and increased frequency of extreme climatic events, such as drought. Not only do these disturbances pose an immediate threat to the functioning of soils, but they could also impair their ability to resist and recover from further stresses that come in the future.

Our project will tackle this problem by addressing two general questions: first, what makes a soil able to withstand and recover from disturbance events, such as drought, and, second how can we use this knowledge to ensure soils can buffer disturbances in the future? These are questions that have puzzled soil scientists for many years, but so far, remain unresolved. An area that offers much promise, however, in tackling this issue is food web ecology. Food webs are the networks of interactions describing who eats whom amongst the myriad organisms within an ecosystem. And in soil, they are the engine that drives the very processes of nutrient cycling and energy flow on which the functioning of soil and the terrestrial ecosystems they support, depend. It has been proposed for many years, but so far not fully tested in soil, that simple food webs are less able to withstand and recover from disturbance events, such as drought than complex ones. We want to test this theory in soil, which harbours some of the most complex, but also sensitive, food webs on Earth. We test the idea, through experiments and models, that the ability of a soil to withstand, recover and adapt to disturbance events depends on the architecture and diversity of the soil food web, which governs the rate of transfer of nutrients and energy through the plant-soil system. We also propose that soil disturbances associated with intensive land use, such as trampling and fertiliser addition, erode the very food web structures that make the soil system stable, thereby reducing the ability of soil to resist and recover from future disturbances, such as extreme weather events. We will also resolve what makes a food web stable, and test the roles of different types of organisms in soil, such as mycorrhizal fungi, which we believe play a major role. And finally, we will develop new models to help us better predict how soils will respond to future threats and to guide management decisions on sustainable soil management in a rapidly changing world.

These question are at the heart of the NERC Soil Security programme which seeks to resolve what controls the ability of soils and their functions to resist, recover and ultimately adapt, to perturbations, such as those caused by land use and extreme climatic events.

Who will benefit from our research?

Project beneficiaries will include the bioscience, ecology and wider scientific research community interested in sustainable and productive food production. Key stakeholders include landowners, farmers groups (e.g. NFU, SNFU, NFUW, HCC, EBLEX, QMS, Soil Association), societies (BES, BSSS), conservation bodies (Plant Life, The Grassland Trust, British Grassland Society, Wildlife Trusts) and local and national government departments (Defra; EA) and agencies (SEPA; EA, Natural England; Countryside Council for Wales, Scottish Natural Heritage) who will benefit as science supported policy develops. We will liaise with BSSS and the Global Soil Partnership to ensure our project goals are integrated into the planned activities for International Year of Soils 2015.
Other beneficiaries are commercial organisations involved in habitat restoration, in particular, horticultural businesses that supply native seed and seed mixes. These businesses stand to benefit from our research through learning (via knowledge exchange; KE) how drought, land management and soil conditions influences communities to resist and recover from the effects of climate change. These organisations also have a financial interest in being able to produce seed mixtures that are stress resistant, and that are more likely to result in habitat restoration that remains successful over the long-term.

It will be vital that our findings are communicated to non-academics and non-researchers within the plant breeding community and end-users. Engagement with these groups will be facilitated though two stakeholder workshops, and through interaction with the Cool Farm Alliance, an umbrella organisation that liaises with numerous businesses with interests in agricultural-related matters. We will also showcase our findings and portfolio of expertise through presentations to farmers groups, building on our existing network forums, public talks and online resources (e.g. You Tube).

How will they benefit from our research?
Data generated in this project will have major implications for our potential to alter soil C and N cycling through land management. A key component of the work is the integration of empirical data with predictive models: this opens up opportunities to gain rapid insight into how specific environmental and edaphic contexts may affect the ability of soils to resist, recover and adapt to perturbations such as drought. Our work will open up the possibility for input of our mechanistic framework into farm management systems, aimed at, for example, coupling enhanced/sustained yields (cf food security) with C storage potential and mitigation of greenhouse gas emissions.

Members of the general public will benefit through (i) an enhanced awareness of climate impacts on biodiversity, (ii) increased knowledge of the role of natural ecosystems in providing valuable goods and services to humanity, and (iii) the role of science in improving the conservation and management of grassland ecosystems and in underpinning our understanding of how the landscape can function for our collective benefit.