Plant responses to a changing climate: linking leaf and global-scale analysis for future food security

Global agricultural production is required to double by 2050 to meet the demands of an increasing population and the challenges of a changing climate. Changing climatic conditions, including increasing temperatures, more variable precipitation, and drought are likely to put pressure on maintaining both high crop yields and a steady supply of food. On the other hand, assuming other factors are not limiting, rising atmospheric CO2 levels may lead to increased crop productivity, as the increased availability of carbon dioxide can promote enhanced rates of plant photosynthesis. The varying abilities of different crops or cultivars to adapt to water, temperature or nutrient pressures signifies the inherent resilience of a given agricultural system, and the likelihood and the degree to which they will be impacted by climate change. Understanding how current and future plant growth conditions affect crop yield is a major priority for ensuring food security, for adapting crop selection and management strategies and for guiding crop breeding programmes. The key challenge here is linking plant behaviour that can be measured at the leaf-level in the laboratory, to plant behaviour at the national or global scale, and predicting future behaviour under forecasted climate conditions. As environmental drivers operate and interact at multiple temporal and spatial scales, addressing this challenge will require transforming how we understand, monitor and predict plant responses to stress.

Observations from satellites have revolutionised spatial ecology in recent years; making it possible to monitor ecological trends over large spatial scales, and to scale from the plant to the globe. Increasingly sophisticated instruments and techniques allow scientists to examine changing vegetation trends in response to climate change from satellites at unprecedented levels of accuracy. These advances have been made possible by sensor developments, an increasing archive of legacy satellite data, and new and emerging techniques such as solar-induced chlorophyll fluorescence, which has been shown to be closely related to plant productivity. Whilst still in its infancy, solar-induced chlorophyll fluorescence has shown potential to remotely monitor crop growth, using drones through to satellites. However, these remote sensing techniques must first be underpinned by a process-based understanding of the connections between the remote sensing signal and plant characteristics. In this research, controlled laboratory experiments will be used to understand how plant stress manifests in changes to the leaf biochemical and structural properties, and in turn, how optical reflectance signatures, can be used to measure these changes. These optical markers will then be used to 'scale up' our observations, first using drone technology at the field scale, and then and at national and global scales using satellite data. This remote sensing data on crop health will be used within sophisticated biosphere models to predict plant performance under current conditions and forecasted future conditions. These approaches in combination will provide a technological basis for a complete picture at different scales, to fully exploit the resources available for crop improvement.

The overarching goal of the research is to assess the ability of nationally and globally important agricultural crops to maintain their growth and performance under different environmental stresses. This research will deploy a cutting-edge, cross-disciplinary approach using controlled growth chambers, novel remote sensing techniques and plant science methods to scale from the leaf to the globe, and provide a step-change understanding in the future pressures that crops may face in light of a changing climate and their underlying resilience.

Maintaining food security and optimising crop yields are widely relevant to the public, the agricultural sector and to national governments. Three main communities of non-academic stakeholders are anticipated, with details on the nature of the impact detailed below:

Industry (primary impacts: technological and commercial)
The main impacts on the economy and industry can be grouped into: 1) technological impacts by optimising and operationalising remote sensing (RS) phenotyping at the field scale. Whilst there are no explicit plans for commercial exploitation of the research, it is likely to provide underpinning knowledge for improving precision agricultural methods, or currently monitoring of crop performance at the field scale, which is likely to be of interest to commercial agricultural companies. If the RS-based phenotyping techniques shows potential for commercialisation we may consider licensing out arising intellectual property; and 2) commercial impacts through the identification of productive crop species and cultivars, which will have direct impacts for farmers/growers. These impacts will express both regionally and globally, to identify areas where yield gaps occur and the limiting factor in achieving maximum yields, identify crops with greater phenotypic plasticity, or resilience for current/future growth conditions, and inform future genetic experimental work to select or develop more suitable cultivars. Growing more plastic or resilient cultivars will maximise plant yields, reducing fertiliser use and improving crop resilience will foster global economic performance, and the economic competitiveness of the UK agricultural sector. The interdisciplinary nature of the work, as it bridges remote sensing and traditional agricultural science will help led to innovative technological advances in plant sciences, as innovative tools and modelling approaches are transferred in into a different academic discipline, to provide in situ field phenotyping.

Wider society (primary impacts - food security, environmental)
The impact from the proposed research will have a significant impact on addressing key UK societal challenges and future UK economic success through seeking to meet future UK food consumption needs and ensuring agricultural stability to the food production industry. It is anticipated that operationalising an in-field phenotyping platform will contribute to precision agricultural applications that could optimise fertiliser application (both spatially and temporally) and reduce the environmental consequences of excess nitrogen use. The public would thus benefit economically, recreationally and in terms of health, as a consequence of the improvements in environmental quality. Other commercial and economic impacts to the general public may include reduced food costs as crop yields are optimised through better crop/cultivar selection and more tailored resource management.

Public sector/Government (primary impacts: influencing public policy and legislation)
The outcomes from the research will inform government policy on food security, with tangible impacts such as a national crop risk-map. Policy-makers within international government will be interested in agricultural trading and supply, at the national level, DEFRA and other agencies and regulators would benefit from this research by providing tools to monitor the global climate change mitigation and adaptation in agriculture, a key project within the government's Parliamentary Office for Science and Technology, with a focus on implications for food security.