On the 1^st of June 2023 over 100 plant health enthusiasts gathered in Edinburgh for the annual Scottish Plant Health Conference. Amid the various presentations and discussions, I had the opportunity to lead a workshop on the often-overlooked issue of plant health and the natural environment. This workshop was a continuation of a recent report published by the Plant Health Centre on plant health and the natural environment, which delved into the potential impacts of biotic agents (pests and pathogens – “pests” for shorthand”) on plant health.

The importance of plant health tends to be more at the forefront of the minds of those working in forestry, horticulture and agriculture than those working in our natural habitats. Yet the health of our natural habitats is critical to, and underpins these sectors, our economy and the many activities that occur in the natural environment such as recreation, and there is good evidence there are considerable risks to plant health in all semi-natural habitats. For example, what would the impact be if a pest severely reduced the cover of Calluna vuglaris (heather) on our Scottish moorlands? Changes to the landscape could be dramatic, with unknown impacts on carbon storage, soil and the wider biodiversity? Although the likelihood of establishment for some of the pests that could impact our natural environment might be low, the ecological impact could be high.

Despite the potential risks, we lack essential tools for monitoring plant health in the natural environment. Three key knowledge gaps include:

1. a way to prioritise which locations or plant species to monitor
2. suitable methods for monitoring plant health, and
3. a reporting system for interceptions or outbreaks of suspected exotic plant pests.

We explored these gaps during the workshop.

Importance to the community and their priorities

As a warm-up exercise and to gain familiarity with the participation app ‘Slido’, attendees weighed in on the importance of plant health in the natural environment. An overwhelming 98% of respondents agreed that it's a matter of significance, highlighting the consensus among the audience, while 90% thought that not enough was being done to monitor plant health in the natural environment (10% didn’t know).

But where, given the thousands of pests and plant species (and limited resources), should our efforts be concentrated when monitoring plant health in the natural environment? Participants were asked to rank five different options for prioritising plant health in the natural environment (Fig. 1).

The monitoring of foundation species - those species that drive key ecosystem functions and support a lot of other biodiversity - was ranked as the best way to monitor plant health. If this option is followed, the next step would be to identify which species act as foundation species within Scottish natural habitats. This could be those species that occur at greatest abundance within a habitat; while this doesn’t follow a strict definition of a foundation species it would provide a simple method to identify species to monitor, and gives a starting point to guide how to target limited resources efficiently. The issue of surveillance methods and resource prioritisation is covered in more detail in the following publication pre-print.  The participants in this workshop were all from a plant health background of some description, and it would be interesting to see if the priorities of more diverse audience, such as the general public, were different.

Eyes on the Ground

When it comes to recording plant health in the natural environment, the workshop participants suggested various actors. Land mangers, the general public and use of citizen science were most commonly suggested (Figure 2). There were also suggestions of using schools, students or subsets of the general public such as gardeners, and walkers. Professionals like NatureScot staff, foresters, RBGE staff, HMU and park rangers were also considered, but whoever does the monitoring would require training and guidance to effectively monitor plant health.

Methods of Monitoring and Raising Awareness

Participants shared diverse ideas for monitoring methods, with a mobile app possessing image upload and geolocation functionality being the most popular choice, although many other methods were proposed including drone, satellite, free-post sample bags and eDNA-based approaches. Some participants suggested an app could perform AI-driven pest identification, while others proposed leveraging existing apps such as iNaturalist, IDphy, TreeAlert, or Seek. Whatever form of monitoring was developed, participants noted that it should be repeated over time to allow long-term trends to be reported. Committing greater resources to NatureScot, Government officials and plant health professionals to conduct monitoring was also recommended by some attendees.

Beyond monitoring, raising awareness emerged as a vital component. Suggestions included training and outreach programs (including schools), "wanted posters," social media campaigns, and even enlisting the support of potential ‘plant health champions’ like David Attenborough.

Reporting Made Easy

In the age of smartphones, a majority of participants preferred using a mobile app to report plant health, over websites or email (Figure 3). However, it should be noted that the workshop attendees can be considered tech-savvy and results might differ across a broader spectrum of society.

Final Thoughts

Firstly, I would like to thank all those at the conference who took part in the workshop - your participation and support are crucial in safeguarding our plant health and the natural world we cherish. This workshop, together with the report and policy guidance on plant health and the natural environment, have clearly highlighted gaps in our understanding and monitoring of plant health in the natural environment. The Plant Health Centre is committed to working with government agencies to address these issues, and we hope to provide updates on our progress at next year's conference. See you next year!

Dr Ruth Mitchell, the James Hutton Institute