- Over the past 30 years, we have lost much of the biodiversity that underpins agricultural production.
- Biodiversity, particularly the diversity of traits of different species, supports key services such as pest control, pollination and soil health.
- BESS has helped to develop a simple approach that enables growers to measure and improve how they support biodiversity and ecosystem services.
- Scenarios for the future of upland Wales are informing debate and policy development.
- BESS research has informed the development of new agri-environment schemes for England.
- It is also important to consider voluntary approaches and the cost effectiveness of farmland conservation options.
The world is facing a potential food security crisis – how can we provide a growing population with a secure supply of nutritious food using less land and fewer inputs in the context of environmental change? The BESS research programme is contributing evidence and tools to help maintain the biodiversity and services that underpin a resilient food system.
BESS research fellow Lynn Dicks created the biodiversity metric of the Cool Farm Tool, which helps growers to make more informed decisions when supporting biodiversity and ecosystem services at a farm scale. The tool is free to growers, simple to use and evidence based. The Cool Farm Alliance includes a wide range of multinational food suppliers and manufacturers and this approach can be scaled up to their supply chains.
Lynn comments that “decision support tools based on unbiased and systematic reviews of scientific evidence are the least well-developed element of evidence based environmental management.”
Invertebrates for natural pest control and pollination
Evidence is emerging from Wessex BESS research that high biodiversity grasslands deliver greater control of crop pests. Enhancing this natural pest control with particular agricultural practices is a key component of Integrated Pest Management, but evidence about the effectiveness of different practices can be hard for growers to access and use to compare options. Lynn Dicks and colleagues collated evidence about these different practices and compared their effectiveness in enhancing natural pest regulation. They found good evidence for five practices, with a ‘push-pull system’ of trap and repellent plants being the most beneficial. However, Lynn comments that there remain ‘substantial gaps in knowledge about the effectiveness of other actions, such as changing the timing of pesticide use’. The BESS programme is also highlighting the implications of pollinator declines and informing policy options to better support pollinators.
How the soil is conditioned by earthworms and plants.
Earthworms are vital in enabling soil to deliver ecosystem services such as nutrient availability, carbon storage and drainage, yet remarkably little is known about how the distribution of earthworms is affected by soil properties and land management. A particularly important issue is whether there are critical thresholds of agricultural intensification after which earthworm biodiversity and the services they provide are threatened. BESS research by Paul Eggleton and colleagues has been investigating earthworm biodiversity in agricultural grasslands that are managed in different ways. Results so far indicate that management changes intended to increase earthworm numbers are best considered at the broad level of what can be done across a whole farm. This can increase earthworm numbers on the farm, but looking at any particular field might not result in the desired effect because biological processes occurring at the field level outweigh the effects of any management interventions.
BESS research is demonstrating that rather than the number of plant species present, it is often the diversity of plant characteristics – traits in a grassland – that affects ecosystem services. Wessex BESS research has shown that grassland soil functions are altered by the trait composition of plant communities rather than species richness. Ellen Fry and colleagues from Wessex BESS have also shown that planting species with a wide range of root depths and architectures increases resistance to drought on chalk grasslands. Their findings can be used to inform species choice in grassland restoration projects.
Upland Scenarios – What will the future look like?
The UK uplands have traditionally been managed with a focus on producing marketable goods - food and fibre. However, the uplands also provide other vital services such as cultural values, clean water, healthy soil and carbon storage. Upland systems and rural communities are under increasing pressure from both local and global drivers of change, such as climate, legislation and cultural change. DURESS researchers worked with industry, NGOs and government to identify the likely land management responses to these possible changes and the consequences of changing levels of market and government influence. This enabled the development of four scenarios of how the UK uplands might develop until 2050 . The DURESS scenarios in brief:
Agricultural intensification Maximising food and fibre production becomes crucial to meet the challenges of food security and increasing global demand.
Managed Ecosystems Ecosystem integrity is pro-actively enhanced to safeguard water, carbon and nature through either public funding of agri-environment schemes or because the market value of these services increases.
Business as Usual Publicly funded agri-environment continues to deliver social benefits and ecosystem services.
Abandonment Land becomes abandoned as a result of market or regulatory failure of the other three scenarios, leading to rapid decline in production and unmanaged development of quasi-natural habitats.
These upland scenarios provide policy makers, land managers and society with alternative realistic visions that can be used to stimulate debate and plan response strategies. For example, the information can be used to create maps for particular areas showing how likely land use change is in different areas.
Developing agri-environment schemes
Research by Lynn Dicks and colleagues has informed the development of a new agri-environment scheme for England . The work assessed which key bee species the scheme should concentrate on, what was limiting populations of these species and what agri-environment schemes could do that would be sufficient to support them. Providing flower–rich habitat on 2 % of farmed land and 1 km of flowering hedgerow per 100 ha can supply these species with enough pollen to feed their larvae (at low estimates of pollen demand). Importantly, this research also highlights the assumptions and uncertainty involved when designing such schemes.
The cost effectiveness of farmland conservation options
While agri-environment schemes are effective at supporting biodiversity, Lynn points out that “we still know very little about whether they support production-related ecosystem services in a way that could make them cost effective” . This issue was also tackled by BESS researcher Zoe Austin and colleagues in a survey of the perceptions of farmers who were following the Conservation Grade environmentally sensitive farming protocol . Options that were perceived as most effective for pollinators, such as improving the floristic diversity of field headlands, were not the most efficient because of their high cost. Actions to improve hedgerow management were most efficient, despite being perceived as less effective for pollinators. Lynn Dicks and colleagues suggest that there are many farmland conservation actions that are low cost to farmers and could be applied voluntarily, without monetary incentives . These include creating uncultivated margins around arable fields and nest boxes for solitary bees.
Managing the spatial pattern of our landscapes
Research under the BESS Location project showed that the structure of our landscapes has a major influence on the other ecosystem services that our farmland can provide. By modelling processes in real and in simulated landscapes, Amy Thomas and Dario Masante showed that the location of woodland on a farm can significantly mitigate nutrient runoff into rivers if it is in the right location. However, the benefits to be gained from increasing woodland cover partly depend on how much woodland you already have.
Resources for policy and practice from BESS researchers:
The Cool Farm Tool Biodiversity module. An online biodiversity calculator for farmers.
Spatial targeting brings new opportunities for agri-environment schemes. An LWEC policy and practice note co-authored by Lynn Dicks.
Managing farmed landscapes for pollinating insects. An LWEC policy and practice note co-authored by Lynn Dicks.
Publications from BESS researchers
1. Cool Farm Alliance, Cool Farm Tool Biodiversity Metric description. www.coolfarmtool.org. 2016.
2. Dicks, L.V., et al., What works in conservation? Using expert assessment of summarised evidence to identify practices that enhance natural pest control in agriculture. Biodiversity and Conservation, 2016: p. 1-17.
3. Prosser, H., T. Pagella, and I. Durance, Upland Scenarios: what will the future look like? DURESS project report card. 2015. www.nerc-duress.org
4. Dicks, L.V., et al., How much flower-rich habitat is enough for wild pollinators? Answering a key policy question with incomplete knowledge. Ecological Entomology, 2015. 40: p. 22-35.
5. Batáry, P., et al., The role of agri-environment schemes in conservation and environmental management. Conservation Biology, 2015. 29(4): p. 1006-1016.
6. Austin, Z., et al., Stakeholder perceptions of the effectiveness and efficiency of agri- environment schemes in enhancing pollinators on farmland. Land Use Policy, 2015. 47: p. 156-162.
7. Santangeli, A., et al., Voluntary non-monetary approaches for implementing conservation. Biological Conservation, 2016. 197: p. 209-214.
Prepared by Laura Harrison, Anna Middlemiss and Charlie Parkin with thanks to Lynn Dicks.