Sentinel Treescapes for Plant Biosecurity and Risk Management - Multiple Threats

Trees play an essential role in sustaining life, providing wildlife habitats and timber and storing carbon, helping to reduce climate change. Tree cover accounts for around 17% of the land area of Great Britain, but trees across the UK landscape, in both woodlands and urban or agricultural environments (the 'treescape'), are currently at risk due to a range of pests and diseases, many of which result in eventual tree death or cause safety hazards due to dead hanging branches or increased risk of tree fall. For example, ash dieback, a disease which arrived in the UK in 2012, could lead to the loss of 90% of the UK's ash trees, currently one of the most common broadleaf species. This project will work with key partners with responsibility for managing trees or ensuring public safety, including the Department for Environment, Food and Rural Affairs (Defra), Network Rail and Norfolk County Council, to develop a monitoring system, which can ultimately be established across the UK treescape, in locations likely to provide an early warning of pest and disease spread (such as near ports or along roads and railways), or of importance for conservation, cultural reasons or public safety, to provide a 'sentinel' system of changes in the health of trees.

The monitoring system, to be deployed in Norfolk, UK, will combine observations from sensors attached to individual trees in the landscape (measuring the condition of the tree canopy, movement of water, tree growth and the motion of the trunk as an indicator of risk of tree fall) with visual observations of tree health made by networks of voluntary 'citizen scientists', including current Tree Council Tree Wardens. Images obtained from cameras on drones and satellites will be used to expand the observations across a wider area and modelling methods will be used to combine the data from these different sources to estimate tree health and detect changes.

A web-based interface will be developed to provide both volunteers and partners with accessible and easily interpreted information from sensors and models, and the experiences of volunteers of working with the technology will be explored through workshops. Models will also be developed to explore the efficiency and cost-effectiveness of different designs of sensor networks and to identify the ideal combinations of and distribution of sensors and observations for future use in monitoring larger areas and more locations. Workshops with partners and other interested stakeholders (e.g. forestry industry representatives or conservation organisations) will be used to examine the best ways in which sensor technology and model outputs can be communicated and the role such data can play in the decision-making processes. The demonstration network, representing a digital environment for tree health assessment and monitoring, will provide a blueprint for future deployment throughout the UK, leading to improved understanding of the spread of pests and diseases and better management of trees.

Five new risks are added every month to the UK Plant Health Risk Register that currently contains >1000 pests and diseases, 30% of which can attack trees. The development of novel methods for monitoring and assessing tree condition is needed for an efficient response to tree health threats and to minimise the risk of new harmful pest and pathogen outbreaks. Monitoring the treescape is important for public safety and vitally important to managing trees across the landscape to help achieve the UK's net zero greenhouse gas emission target by 2050. The annual value of the ecosystem services offered by Great Britain's treescape that can explicitly be monetised, is £4.9 billion per year (> 0.2% of national income). Nevertheless, this essential natural asset is under regular threat by pests and pathogens, potentially having huge economic implications, for example, it is estimated that the outbreak of ash dieback is set to cost the UK in the region of £15bn.

This project will demonstrate a sentinel treescape digital environment of in-situ sensors, drone and satellite observations, integrated with citizen science, to monitor tree health and stability, allowing early-stage detection of stress. The second part of the project will integrate data layers across multiple spatial and temporal scales, to determine sensitivity of the sentinel system to tree health status and will utilise modelling approaches using agent-based and network models to assess the cost and effectiveness of different sensor technology combinations and configurations and to predict risk. The project will use treescapes along infrastructure features, road and rail, as the demonstrator but through modelling of the optimal sensor deployment, will provide a blueprint for a monitoring platform that could be deployed to sentinel treescapes across the UK landscape.

A number of stakeholders, including the Department of Environment, Food and Rural Affairs (Defra), Forestry Commission/Forestry Industry (monitoring/modelling of the wider landscape will allow better planning in commercial forest stands), The Tree Council, Network Rail, Highways Agency, National Trust, Woodland Trust and County Councils have the mandate for tree's wellbeing and safety, or for conservation and preservation of key habitats, ecosystem services such as carbon storage or cultural features, which may be threatened by tree health decline.

Primarily, these stakeholders follow conventional methods to monitor tree health. Monitoring of tree health through visual inspection is prone to error and bias and consumes time, monetary and human resources. Thus, it would be in the interest of stakeholders if tree health could be assessed and monitored in a rapid manner while utilising low-cost sensors/technologies. Following demonstrator optimisation for reliability and scalability, it has the potential to integrate into the UK's digital environment, providing a near real time monitoring of biosecurity threats to tree health and physical risks to tree stability. This would be extremely valuable to multiple stakeholders, from national and local government to research institutions and private businesses, and the project will seek to engage these wider stakeholders from an early stage.

It is vital to engage the general public in the development of the UK's digital environment, communicating activities, methods and results via social media and local/national press and media. It is envisaged that this project will, if successful, engage with other digital environment demonstrators across this call and these demonstrators will integrate into the UK's growing digital environment. Public engagement at these early stages, heightened by 2020 being the international Year of Plant Health, will be essential for driving environmental monitoring forward via a digital environment, potentially engaging the public exponentially in a citizen science environmental revolution.