Optimising multifunctional land-use decisions through robust combined models: a pollination-crop yield-landscape aesthetics case study

Making land-use decisions is complicated because there are many competing demands (environmental, social and economic) placed on our landscapes. The decisions we make at small scales can have much larger and longer-term consequences. For instance, in arable landscapes, converting field margins to crop to maximise crop yield in a given field (economic benefit), will reduce pedestrian access beside crops (social benefit) and reduce resources supporting landscape-scale biodiversity (environmental benefit). Lower biodiversity can in turn reduce pollination service and therefore crop yield, not only in the original field, but also in surrounding fields. The consequences of a land-use choice in one field can therefore spread far beyond that field and affect many different benefits. This means that it is essential to assess the impacts of land-use decisions on all of these benefits simultaneously, in order to make the most informed land-use decisions at the landscape scale. Although many statistical models allow us to measure individual benefits in great detail across the landscape, very few combine multiple benefits, and those that do, typically do not consider the feedbacks between different benefits due to their additive model structure. Furthermore, these existing combined models rarely account for the time-dependent aspects of benefits derived, which can be significant for land-use choices such as woodland creation, which takes decades to reach their full biodiversity benefits.

Our project will combine physical science expertise in building spatially-explicit time-dependent computer models with expertise in ecology, sociology and economics to develop the first modelling framework that combines multiple interacting landscape-scale benefit models, to identify land-use choices that maximise the ecological, social and economic benefits provided by the landscape over time. The project will use pollinators and the benefits they provide in agricultural landscapes as a case study for model development, because agricultural land-use interventions for supporting pollinators affect environmental (by supporting biodiversity), social (by affecting the scenic quality of farmland), and economic (by determining pollination service to crops) benefits simultaneously. Our model will therefore combine and interlink three individual benefit models - a pollinator abundance biodiversity-benefit model, an aesthetic value social-benefit model and a monetary crop value economic-benefit model - into a single cohesive whole. It will also account for how the benefits provided by interventions such as flower strips and hedgerow creation can change over time. We will test the model on a series of real agricultural landscapes incorporating varying amounts of pollinator interventions to identify the optimum proportions of interventions required to maximise the environmental, social and economic benefits provided by the landscapes over time.

The outcomes of this project are directly relevant to designing future UK agri-environment schemes, and we will work with project partners to demonstrate the potential of the combined model framework to inform real-world land-use decisions. The modelling framework can then be expanded in future to include other benefits (e.g. abundance of other species, water quality/quantity etc.) and identify optimum solutions for other land-use systems with competing environmental, social and economic demands (e.g. new developments balancing housing needs with green infrastructure).

The project will benefit the following groups:

- Statutory agencies involved in agri-environment scheme design and implementation, such as Defra (project partner), Natural England, Natural Resources Wales and Scottish Natural Heritage. These organisations use limited resources to advise and incentivise landowners to deliver multiple public benefits from their land in the most efficient way. Our pollinator-crop yield-landscape aesthetics case study will yield products directly relevant to the design of Defra's new Environmental Land Management Scheme for England, by identifying region-specific proportional targets for pollinator interventions, which optimise the balance of environmental, social and economic benefits. These targets will be directly transferable to lowland agricultural regions in Wales and Scotland with similar land-cover and the combined model can be run on any input UK landscape, providing a powerful tool for these agencies to use to compare the predicted benefits derived from different land-use scenarios.

- Farmers and farm advisors. Project results will be of particular interest to farmers interested in maximising yields though wildlife-friendly farming approaches and/or in diversification into the tertiary sector by providing additional recreational activities on their land. More generally, the project results can be used to show farmers ways to deliver environmental and social benefits without negatively impacting on crop production. Our pollinator-crop yield-landscape aesthetics case study will yield regional proportional targets for pollinator interventions that account for the habitats already present in those regions. These results will be summarised in a short video and a simple online tool, allowing farmers to look-up the recommended proportions of interventions for their particular farm, based on their regional location and the current habitat proportions their farm already provides. Our project partners, NFU, aim to help farmers to increase biodiversity and aesthetic benefits and augment these minimum recommendations with additional interventions.

- Individual landowners with a strong focus on delivering social and biodiversity benefits (e.g. National Trust, Wildlife Trusts, RSPB) within farmed landscapes. Our combined model would allow these landowners to quantify the current environmental and social benefits their land provides and to assess the potential benefit increases provided by additional short and long-term interventions. This would allow them to identify future strategies that provide maximum benefits for minimum cost and so help them to justify any bids for additional funding that they may require to carry out these interventions.

- General public. There is extensive and growing public interest in UK pollinators. The project team will create a dedicated webpage for the project, within the project team's existing pollinator research webpages. The webpage will include accessible summaries of the project aims and results to raise awareness among the general public of the importance of the project and its findings for both pollinators and people.