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.
Although Xylella has so far not been detected in Scotland, an outbreak would have serious impacts on any host plant-related activities/businesses and the wider environment. An essential aspect of ensuring Scotland’s preparedness for the possible arrival of Xylella is to prepare a risk map for the likelihood of the arrival of Xylella together with the consequences for key elements of the Scottish economy (directly and indirectly impacted) in the event of an outbreak. Data relevant to the risk mapping for Scotland would include location of sites involved in plant imports, volume of plants imported, impact on business trading in plants if an outbreak is detected and the wider environmental impact.
Impact: This project will contribute to Scottish Government’s contingency and preparedness measures for the possible arrival of Xylella fastidiosa by mapping the risk of likelihood and impact of an outbreak.
There are several species of insects that could vector Xylella fastidiosa in the UK including the meadow spittlebug (Philaenus spumarius), which is very common in Scotland. An outbreak of Xylella in Scotland would have serious impacts on the affected grower/nursery and any other host plant-related activities/business within a 5km buffer zone. Therefore, in order to establish the potential for these bacteria to spread, should they be introduced, it is important to identify and get an understanding of the abundance of potential Xylella vectors in Scotland. The WrEN project (http://www.wrenproject.com/), presents a unique opportunity to make use of existing insect collections to map the occurrence of potential Xylella vectors within agricultural woodlands across Scotland. Since 2013, partners on the WrEN project have surveyed over 130 secondary and ancient woodland sites for habitat and wildlife in two regions of mainland Britain. To date, over 1100 species have been recorded from a wide range of taxa. Vegetation structure has been characterised at all sites including information on tree species richness, tree density and size, understorey and canopy cover. In addition, the surrounding landscape has been mapped at a range of spatial scales up to 3 km from each site.
Impact: This project will contribute to Scottish Government’s preparedness measures for the possible
arrival of Xylella fastidiosa by identifying and mapping the distribution of potential vectors of Xylella
PHC commissioned an assessment of large-scale biosecurity risks with a focus on three areas of concern: (1) non-specialist and online horticulture sales; (2) landscaping and infrastructure; (3) 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.
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.
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.
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.
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.
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.
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.
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.
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Oak Processionary Moth to Scotland.
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
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
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
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from longhorn beetles to Scotland
Status, Scottish specific issues, Plant Health Centre perspective and Key priorities and recommendations concerning the threat from Phytophthora ramorum to Scotland
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 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?
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.