Environment
Scotland has a remarkable assemblage of species and habitats with Atlantic, montane, boreal, arctic-alpine, and oceanic habitats in close proximity. However, pests and pathogens represent an increasing threat to these natural assets, and a particular challenge is the sheer complexity of the diversity of the natural environment in terms of the number of species that may be impacted.
Scotland is internationally important for its resources of blanket bog, heather moorland, Atlantic rainforests, montane native woodland (e.g. Caledonian Pine forests) and high nature value farmland (e.g. machair). These habitat types represent a major tourism draw to Scotland as well as being of significant value for biodiversity and ecosystem service provision. Increasing global trade is, however, resulting in native species encountering novel pests and pathogens, and in addition, changing climatic conditions can increase susceptibility of species in the natural environment to endemic plant health threats.
Access our resource bank on plant health issues for the natural environment here.
Knowledge Bank
Projects
• Expert visitation of sites to seek evidence of problems with alder health, gain some understanding as to possible causes, and identify key dimensions of a thorough study should this prove warranted. Lab work to confirm field diagnoses.
• Preliminary citizen science request inviting site-specific records of concern over alder health (potentially via the trained Observatree volunteer network to gather data), with analysis to identify any geographic clustering.
• Produce recommendations for further work including; refined survey methodologies for widespread application by interested organisations; identification of potential candidate sites for detailed study over time, and; a discussion document on risks to existing alder of expansion of riparian woodland.
Drawing upon and summarise existing literature, in addition to engagement with experts and practitioners with knowledge of existing sectoral practices in Scotland, UK and internationally, as well as gap analysis, the project will generate a better understanding of the rationale for taking precautions and an improved evidence base with which to justify taking action, answering four main questions:
• What are the current barriers to adopting precautionary measures?
• How can barriers be reduced?
• What are the limitations of the current risk assessment process?, and
• What are the priority areas for action and further research?
This work will examine and define the extent to which current UK and Scottish regulations and voluntary schemes control the way growing medium constituents must be treated prior to their inclusion in growing media, to generate an understanding around mitigating risks of spread of plant pathogens. Workshops with stakeholders will improve understanding of current practices and perceptions of alternative ‘best practice’ options for nurseries managing waste materials and for biosecurity risks of using reduced peat and peat-free growing media. A concurrent diagnostic study will identify Phytophthora species present in waste heaps from nurseries located in Scotland and the potential for these pathogens to spread into healthy plant stock either aerially or via water run-off and soil transfer.
Findings will be combined with a comprehensive desk-based study and feed into follow-up workshops on the development and introduction of ‘best practice’ guidance on the most appropriate and safest ways to manage waste growing media and plant material, to be built into the Plant Health Management Standard.
• How can important plant species in botanic collections and historic gardens be protected from inadvertent disease introduction on the footwear, etc. of visitors?
• What is the risk of further inadvertent spread from gardens into the natural environment?
• How can gardens, nurseries, farms and the natural environment be protected from pest and disease spread through the movement of large machinery (e.g., tree harvesting machines)?
Through a desk based study that incudes literature review, contact with plant health authorities, semi-structured interviews with landowners and expert practitioners from other sectors, the project will; determine what official biosecurity advice already exists and procedures are in place in Scotland; explore other sectors which provide additional novel approaches to biosecurity; and carry out a thorough assessment of what procedures are in place, or being considered and developed, in different countries/regions to address these specific biosecurity risks.
1. What is the overall goal and vision for PHC and how do we articulate this for different groups and sectors?
2. What do we want to communicate, when and to whom?
3. How do we want to communicate to different audiences and for these different purposes?
4. How do we optimise budget and human resource in communicating about plant health?
Impact: The outcome of this project will be a Communication Strategy outlining the goal of communication, roles and responsibilities and a process, including an annual cycle of reflection to permit update or modification on a regular basis and linking to the communication matrix.
Therefore, a small desk study was undertaken by Forest Research to provide a firmer evidence base and begin to identify the nature and scale of alder health problems in Scotland. A request to Scottish Forestry’s Tree Health team for information of sites at which alders are currently displaying symptoms of poor health identified 15 sites. The symptoms displayed at these sites differed widely and are a strong indication of different agents being associated with the decline of alders at different sites. Collation of the data for these sites is now complete and provides a firm basis upon which to carry out targeted field visits when fieldwork becomes feasible. Discussions are underway between experts at FR, RBGE, Hutton, and NatureScot to consider options for fulfilling the objectives of the original project call.
Impact: This fellowship will generate an increased understanding of current and future plant health threats to the natural environment in Scotland and identify key knowledge gaps, and deliver practical steps and actions to minimise risks and negative and provide evidence-based advice to inform future policies to help safeguard this sector.
Impact: Keep plant health and biosecurity at the forefront of our stakeholders’ minds, and a high priority for them, raising stakeholder awareness about the risks from plant pests and pathogens and the solutions available for their management and control, and raising the profile of the Plant Health Centre and our online resources.
This project is being conducted on behalf of the Plant Heath Centre, Scottish Forestry and NatureScot and aims to better characterise the threat of BBB to Scotland.
Impact: Draw together available evidence and, where feasible, gather new evidence relating to the threat of Bronze Birch Borer to Scotland; and provide information to inform contingency plans and make recommendations for further work to refine the evidence.
Impact: Identify accurate, efficient and trusted sources and test whether these sources are influential in appropriate usage of control options across key arable regions and crop types, plus intervention tools or methods that might be needed to manipulate or change how information flows; bespoke to the needs of the Scottish stakeholder network.
Publications
Integration of Plant Health Planning Into the Scottish Biodiversity Strategy
The impacts of introduced plant pests and diseases have been substantial in recent times. With a changing climate and many known pests on the horizon, plant health impacts on biodiversity are expected to grow further in the years ahead. Thus, considering the nature of plant health threats to the natural environment and embedding mitigating actions into biodiversity strategies is of increasing importance.
Understanding a new health threat to Caledonian Scots pine (Pinus sylvestris)
This project was initiated in response to a new health threat to Scots pine manifesting itself in the form of multiple blackened cankers and dieback of shoots and branches, particularly in the lower crown. Scots pine is regarded as iconic in Scotland for a range of ecological, cultural and economic reasons. Therefore, it is a research priority to gain an understanding of the extent and causes of the canker disease for better protection of this species in the future.
Assessing spread of Phytophthoras in Scottish forests by recreational and harvesting activities using comparative qPCR and metabarcoding techniques
Pathogens from the genus Phytophthora pose some of the greatest threats to tree health and are likely to become increasingly prevalent in the UK as the climate becomes warmer and wetter. This project added new data based on a DNA metabarcoding approach to determine the Phytophthora species diversity in soil samples and sampled material from timber harvesting operations alongside those of recreational activities.
Action Research to gain a deeper understanding of large-scale biosecurity risks to Scotland
This project has developed a systems approach, in the context of plant health biosecurity risks in the retail, infrastructure landscaping and planting in the natural environment, to facilitate further understanding of key organisations and identify general and specific leverage points at which interventions could have a significant effect on the system.
Plant Health and the Natural Environment Fellowship
The Natural Environment sector underpins Scotland’s landscapes, biodiversity, rural industries and recreational activities, but plant health awareness is less well developed than in the forestry, horticulture and agriculture sectors. The PHC funded a fellowship with NatureScot, to address this gap.
Preliminary investigation into the threat of Bronze Birch Borer (BBB - Agrilus anxius) to Scotland
The Bronze Birch Borer (BBB, Agrilus anxius) is a major threat to birch trees. This project had co-funding from Scottish Forestry and NatureScot and undertook evidence gathering to assess the threat BBB poses to Scotland, inform risk assessment, surveillance and contingency planning, and identify key risks and knowledge gaps.
A targeted analysis of the impact of insecticide withdrawals in Scotland, in the context of alternative control options
Insecticides are commonly used in Scottish agricultural, horticultural, forestry production, and for amenity and natural environment management purposes. Over the last 10 years, approximately 50% of UK insecticide active substances have been withdrawn due to increasing concern over human health and environmental impacts. Some of these losses will be mitigated by using alternatives but their practicality and cost under Scottish conditions is unknown. This project analysed current crop production patterns and insecticide use in combination with how likely different insecticides are to be withdrawn and provided stakeholder views on the impacts of any such losses on their industry, including other control methods that may be adopted.
PHC Annual Report 2022-2023
The Plant Health Centre works with Scottish Government, public bodies and stakeholders to provide scientific evidence to help them make important decisions about pests and pathogens that threaten Scotland the most. Over the past 12 months we have delivered a consistent programme of stakeholder engagement and project commissioning, which are detailed in our annual report.
Biosecurity practices to support plant health: a review of knowledge and practice
This research investigated plant biosecurity risks from site visitors, tools & equipment, and large machinery. In addition to reviewing published guidance, UK businesses and organisations were engaged via questionnaires and interviews to explore how these aspects of biosecurity are understood and what procedures may be in place to address them.
Identifying the plant health risks associated with plant waste disposal and peat-free growing media and developing best practice guidance for waste disposal and composting across sectors
This research focussed on two areas of biosecurity that provide significant risk to plant businesses and the wider environment in Scotland, i) plant waste management, and ii) the constituents of reduced-peat and peat-free growing media.
Enhancing the Plant Health Centre’s communication with stakeholders
This project was commissioned to implement a selection of the recommendations made in the PHC stakeholder engagement strategy and communication plan. The team developed strategies to manage time and resources of the Plant Health Centre more efficiently regarding communication of outputs, general information on activities, aims and current issues related to plant health.
Improving knowledge of Xylella fastidiosa vector ecology: modelling vector occurrence and abundance in the wider landscape in Scotland
If introduced to the UK, the insect-vectored, bacterial plant pathogen Xylella fastidiosa could be a serious threat to trees and other plants. There is a lack of knowledge about the ecology and distributions of Xylella vectors in Scotland and the potential effects of this on any outbreak of the disease, which this project aimed to address.
A review of gene editing for the benefit of plant health
This report is the output of a call-down project that assesses the type of plant health problems in Scotland that GE could address, with potential benefits, barriers to deployment and dis-benefits noted.
Assessment of large-scale biosecurity risks to Scotland
PHC commissioned an assessment of large-scale biosecurity risks with a focus on three areas of concern:
- non-specialist and online horticulture sales;
- landscaping and infrastructure;
- planting for environmental benefits.
An additional area was the potential for modelling to support decision making across these areas of concern. This policy report summaries each report and highlights the key findings and suggested actions.
Assessment of large-scale plant biosecurity risks to Scotland from non-specialist and online horticultural sales
This project focused on an initial exploration of tree and plant biosecurity risks to Scotland arising from large-scale movement of plants via non-specialist (those for which plants are not their primary product type, e.g., supermarkets, DIY and lifestyle stores) and online plant retailers. By better understanding the characteristics of these retailer types, the plant health behaviours they undertake, and the challenges they face, potential avenues were offered for greater engagement and collaboration on biosecurity with this important, but understudied and hard to reach sector.
Assessment of plant biosecurity risks to Scotland from large scale plantings for landscaping and infra-structure projects
Planting for large-scale landscaping and infrastructure can typically involve tens of thousands of individual plants, potentially threatening plant health in Scotland due to the biosecurity risks of imports and widespread planting of infested or diseased plants. This project aimed to understand the extent and means to mitigate against such plant biosecurity risks with a focus on mapping the pathways from plant specification through to planting and establishment and highlight different biosecurity awareness for actors, in decision-making and procurement processes.
Assessment of plant biosecurity risks to Scotland from large scale tree plantings for environmental benefits
This report features five case studies from across Scotland and examines risks associated with large scale tree planting schemes, levels of awareness around pests and diseases, and how the decisions and actions of those involved can serve to reduce or exacerbate pest and disease related threats and long-term tree health. Each case study was unique in respect to their combination of location, site conditions, ownership, management objectives, species choice, supply chains and management activities. By highlighting best practice and lessons learned, it was hoped to ensure that future planting schemes can be successful and, importantly, reduce the likelihood of pests and diseases being introduced and spread into the wider environment.
The potential of ecological and epidemiological models to inform assessment and mitigation of biosecurity risks arising from large scale planting
Large scale planting projects linked to infra-structure such as transport networks and major housing projects or to planting for environmental benefits (e.g., urban greening, woodland restoration) pose high biosecurity risks due to the high number and types of plants involved. This report focusses on whether and how ecological and epidemiological model frameworks can inform assessment and mitigation of biosecurity risks from large scale planting using a combination of literature review and stakeholder engagement. The project aimed to identify priority steps to develop more useful models and tools for assessing biosecurity risks from planting in the future.
Assessment of suitability for EAB invasion for Scotland and the UK
Emerald Ash Borer (EAB) has become a significant threat to ash trees in several countries (including USA and Russia) but is not yet present in the UK. We quantified climate and ecological factors affecting EAB suitability using native range data and conclude that southern England is a highly suitable habitat for EAB. Although currently less favourable, we project that Scotland will become increasingly suitable for EAB under climate change. Thus, EAB could threaten Scotland via trade with areas where it is present or, through spread from populations if established in England or Western Europe. Rapid spread of EAB has been observed in its US invasion. We therefore recommend further study and vigilance against EAB introductions into the UK.
A stakeholder engagement strategy and communication plan for Scotland’s Plant Health Centre
The aim of this project was to develop an operational communication plan from existing stakeholder engagement principles, communication theories and knowledge banks, identifying and summarising actions for the PHC.
Metabarcoding analysis of Phytophthora diversity in spore traps and implications for disease forecasting in the P. ramorum management zone
Surveillance and monitoring of airborne pathogens is a key tool in the management of healthy forests and controlling disease outbreaks. A Scottish Forestry-funded project was carried out in autumn 2019 to validate different spore-trapping techniques for monitoring airborne P. ramorum inoculum using a species-specific qPCR assay. This project aimed to add further value to the Scottish Forestry project by investigating the suitability of DNA metabarcoding for screening spore trap samples for P. ramorum and other Phytophthora species, seeking early data for aerially dispersed Phytophthora species that may become problematic in UK forests. The study highlighted the value of both monitoring P. ramorum dispersal and detecting other Phytophthora species, to predict and understand changes in disease severity in UK tree host species. Recommendations included that the use of both rain and wind-borne inoculum capture methods might be advantageous due to the variety of weather conditions under which inoculum can disperse. Lineage testing in Southwest Scotland should be carried out to look at the prevalence of lineage EU1 in the EU2 area and to monitor for presence of North American lineages. Development of a new DNA barcode more specific to Phytophthora would be beneficial.
PHC2020/09: Economic Impact of Pesticide Withdrawals to Scotland, with Case Studies
Chemical forms of plant protection are widely used in Scottish agricultural, horticultural and forestry production plus for amenity and natural environment management purposes. The availability and use of active substances in pesticides are closely regulated and increasing concern over human health and environmental impacts has led to a greater likelihood that some existing approvals will be withdrawn and/or that approvals for new products will not be granted. Potential impacts from withdrawal of these pesticides are of policy interest and this summary report builds on the data and results from project PHC2018/15 (Potential impacts arising from pesticide withdrawals to Scotland’s plant health) and uses case studies to understand the likely magnitude and distribution of potential impacts and how they may be mitigated.
PHC2018/15: Potential Impacts Arising from Pesticide Withdrawals to Scotland’s Plant Health
The use of pesticides to manage plant pests and diseases is a key management intervention across plant health sectors, particularly in agriculture, horticulture and commercial forestry production. Pesticide withdrawals through legislation, coupled with resistance development and their impact on plant health, have emerged as key concerns for Scottish plant health stakeholders. This project quantifies the impacts on Scottish plant health that will arise from pesticide withdrawal scenarios and sets this in the context and time frame of alternative management tools.
Impact of climate change on the spread of pests and diseases in Scotland
This project constructed a modelling framework which combined epidemiological and economic modelling. The modelling framework was used to study predictions of spread and economic impact of pests which are not currently in the UK, including Xylella fastidiosa, Candidatus Liberibacter solanacearum (Zebra chip) and Ips typographus (Eight toothed Spruce Bark Beetle).
Impact: A web/desktop application is available to the PHC and Scottish Government to analyse the effects of climate change on the spread and economic impact of new threats.
Expansion of PHC Online Plant Health Resources
This project has expanded the PHC online Resource Bank for plant health threats to the Natural Environment sector in Scotland to include information sources for the remaining three sectors (Forestry, Agriculture and Horticulture). Information sources for Forestry, Agriculture and Horticulture were compiled and evaluated, and a Knowledge Bank relevant to each sector is now online at the PHC website, creating a comprehensive and unique signposting resource for plant health information with relevance to Scotland.
18-Month Review Summary Leaflet
The Plant Health Centre completed an in-depth review of its first 18-months of activity for our funder (the Scottish Government through RESAS) in September 2019. While the full report is not yet available to the public, we have created a summary leaflet that outlines out achievements over this period.
Threat: Oak Processionary Moth
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Oak Processionary Moth to Scotland.
Threat: Bud worm
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from the Eastern spruce budworm (Choristoneura fumiferana), Western spruce budworm (C. freeman) and Black headed budworm (Acleris gloverana and A. variana) to Scotland
Threat: Emerald ash borer and Bronze birch borer
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Emerald ash borer and Bronze birch borer to Scotland
Threat: Larger Eight toothed spruce bark beetle (Ips typographus)
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from the larger eight toothed spruce bark beetle (Ips typographus) to Scotland
Threat: Longhorn beetles
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from longhorn beetles to Scotland
Threat: Phytophthora ramorum
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Phytophthora ramorum to Scotland
Threat: Xylella fastidiosa
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Xylella fastidiosa to Scotland
Development of an online, user friendly plant health resource bank for the Scottish Natural Environment
The aim of the project PHC2018/11 was to compile a resource to be embedded within the Scottish Plant Health Centre (PHC) website, with the following three main purposes: 1) To direct users to existing, comprehensive and reliable plant health information resources; 2) To provide information on selected plant health threats to the natural environment, particularly invasive non-native species; and 3) To direct users to appropriate government agencies and resources and advise users on steps to take should a suspected statutory pest or disease be encountered.
Webpages have been developed which provide the following:
1) a listing of the first most pressing plant health threats to the natural environment in Scotland;
2) a user-friendly web template, populated with links to information about these major threats and other topics relevant to plant health in the Scottish natural environment; and
3) summary pages providing guidance on biosecurity and control of diseases in this sector, for which other resources were not easily available.
The use of mobile technology to enhance plant health monitoring and awareness in Scotland
The aim of the project was to review existing websites and smartphone apps currently available and applied in the plant health sector and to assemble a detailed overview covering the following points:
- What options are available in terms of mobile software applications for plant health?
- What is their primary purpose?
- Who is the target audience (growers, plant health professionals, citizen science, …)?
- Which plant health sectors do they cover?
- Are they reliable and accurate?
- Is information submitted to a central database? If so, how is this information used?
- Could they be used globally, or are they limited to certain geographic regions?
Difficult choices to protect gardens and the environment
Heritage gardens play an important role in plant conservation. They house collections gathered over decades or even hundreds of years, including varieties of plants that may be overlooked elsewhere, fostering heirloom varieties and preserving biological diversity that is the raw material of adaptation. As well as being beautiful and tranquil sites of cultural heritage, these ex-situ resources are treasure troves of biological diversity. Arduaine Gardens shows us that tough choices can be necessary and important to preserve these collections and the surrounding environment.