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.

 

Projects

Project Lead: Carolyn Riddell
The oomycete Phytophthora ramorum has caused substantial losses of Scottish forests in recent years due to widespread mortality of European larch trees (Larix decidua). Since 2009, legislation and policies have been implemented to control P. ramorum outbreaks on larch including the use of a 250 m larch ‘fire-break’, although it is unclear whether this distance is optimal for disease control. A project funded by Scottish Forestry is using a P. ramorum-specific qPCR assay to compare several spore trapping techniques for quantifying wind- and rain-borne inoculum and to better estimate inoculum dispersal distance. This project adds value to that of the Scottish Forestry-commissioned work, through evaluation of metabarcoding as an alternative method to both monitor P. ramorum inoculum dispersal and detect a broader range of aerially dispersed Phytophthora species. A second objective is to determine the lineage composition of P. ramorum inoculum throughout the observed peak sporulation period.

Impact: Timely management and prioritisation of policy to manage P. ramorum and facilitate early forecasting of other Phytophthora outbreaks.
Project Lead: Glenn Marion
Dendroctonus Micans (D. micans) is a significant beetle pest of commercially important spruce species. The beetle is spreading north from England and is now present is Scotland. The spread of the beetle threatens the D. micans Pest Free Area (PFA) in west Scotland. This designation allows the transfer of the Scottish Spruce crop from the PFA to Irish sawmills, as Ireland is a D. micans free area. The Central Belt of Scotland is a relatively spruce free area and may act as a natural ‘firebreak’ to slow or stop the spread of the beetle. Scottish Forestry collect field data in annual surveys and release an obligate predator (i.e. a predator that can only survive in the presence of D. micans) at sites with observed D. micans infestation and sites believed to be at high colonisation risk. This project conducted a proof of principle study to assess whether developed computational tools could add value to the field data in annual surveys by Scottish Forestry to parameterise models of the spread of D. micans in space and time. The fitted model was also used to project scenarios of future spread.

Impact: Informed the control efforts of Scottish Forestry by predicting the spread of D. micans in Scotland and identifying the high-risk areas of colonisation. This project built on methods developed under the RESAS SRP and led to work commissioned by Scottish Forestry to inform their surveillance and control programme in 2018.
Project Lead: April Armstrong
The oomycete Phytophthora ramorum has caused substantial losses of Scottish forests in recent years due to widespread mortality of European larch trees (Larix decidua). Infected trees are subject to statutory felling notices in an effort to reduce sporulation potential. Nevertheless, there are concerns about the multiple pathways by which spores might be transferred to new sites. There have been assessments of soil moved by mountain biking and walking/running resulting in evidence to support the Forestry Commission’s Keep-it-Clean campaign. This study will assess soil/plant material collected from commercial harvesting equipment (tyres, treads, mud guards etc.). PHC support will enable a wider range of diagnostic tests to be carried out, testing the robustness of the methods and examining the potential for multiple Phytophthora species to be transferred.

Impact: Add to the evidence base underpinning public and sector-facing biosecurity campaigns and improve disease management and restrict spread of the disease.
Project Lead: Daniel Chapman
Xylella fastidiosa is a bacterial plant pathogen that can cause disease in a broad range of hosts. Disease symptoms include leaf scorch, wilting of foliage, dieback and plant death. Xylella fastidiosa was first detected in Europe in 2013 in Puglia in Italy and was identified as subspecies pauca which has gone on to devastate olive plantations in this region. There are currently major Xylella outbreaks in Southern France, including Corsica, Italy, mainland Spain and the Balearic Islands. Although Xylella has so far not been detected in Scotland, an outbreak would have serious impacts on any businesses where Xylella is detected and the wider environment. An essential aspect of ensuring that Xylella is not introduced to Scotland is to establish, through modelling, that national surveillance monitoring aimed at detecting a Xylella outbreak is effective. In addition, it is important to identify which epidemiological parameters most strongly influence the effectiveness of surveillance, to guide where future empirical research should be targeted to reduce any uncertainty.

Impact: This project will contribute to Scottish Government’s preparedness measures for the possible arrival of Xylella fastidiosa by ensuring surveillance monitoring is effective and by identifying the key knowledge gaps for effective surveillance.
Project Lead: Adam Kleczkowski
The movement of plant pests and pathogens into Scotland in likely to increase in the coming years, e.g. due to changes in trade, potentially increasing from outside Europe following Brexit, while their spread and severity could be affected by climate change (both positively and negatively). It is therefore vital that we understand the role of climate on the impacts of such pests and diseases across the whole of Scotland, in relation to the distribution of plant hosts, allowing us to target potential control options on the main threats. To allow plant health professionals and others to assess such impacts in as straight forward a way as possible, web- / desktop-based tools are needed that offer quick and easy access to complex computer models. These models should be as comprehensive as possible, allowing new information on pests, pathogens and their hosts to be added as it becomes available.

Impact: Easily accessible tool for PHC and government plant health officials to assess possible impacts of climate on pests and pathogens in Scotland.
Project Lead: Katherine Hayden
Pests and diseases represent a major emerging threat to biodiversity, in part due to increased global trade, climate change, and wider habitat degradation. The potential impacts include direct threats based on pest/pathogen impacts on focal species, as well as wider secondary effects for other interacting species and communities.
Compared to threats such as climate change and habitat fragmentation, plant health issues are poorly represented in international and national biodiversity strategies such as the Aichi Targets of the Convention on Biological Diversity, the Global Strategy for Plant Conservation, and the Scottish Biodiversity Strategy. Work is thus required to provide strategic guidance on the inclusion of plant health threats into the next iteration of the biodiversity strategies.

Impact: Direct guidance and input for plant health issues into the new Scottish Biodiversity Strategy; best-practice example of plant health integration into national biodiversity planning (model for other countries).
Project Lead: Katherine Hayden
Plant health issues for the natural environment are poorly characterised compared to other sectors. This is compounded by the lack of established conferences / knowledge exchange events targeted at this sector. A key issue identified by stakeholders was lack of accessible information / authoritative summaries of key plant health threats to native biodiversity and natural ecosystems.
The aim of this commission is to establish the template and initial population of a curated online resource bank for plant health threats to the natural environment in Scotland. This will include assembly of, or signposting to, available existing resources. Where applicable, it will also include authoritative distillations of the key issues targeted at non-specialists. Where there are conflicting sources of advice/recommendations, the scope is not to achieve reconciliation of these issues, but rather to simply note that different perspectives exist. The content will be housed on the Plant Health Centre website (https://www.planthealthcentre.scot/).

Impact: Increasing the accessibility of information for land managers with responsibility for the natural environment, but a lack of specialist expertise in plant health
Early scoping of plant health priorities with key Scottish stakeholders and discussions at the PHC launch event indicate a complex landscape of plant health information sources, confusion amongst stakeholders and a perception of information overload. To inform future KE methods and priorities, a network analysis is required to identify the sources of information and the strength of their effect on Scottish stakeholder communities.

Impact: Improved understanding of concepts and options amongst the Scottish stakeholder community; a basis for gap analysis by the PHC.
Project Lead: Steve Woodward
Discussions at the PHC launch event, and between sector leads, indicate some distinctive and different approaches to tackling pests and diseases in Scotland are to be found across sectors and between businesses/units. Some focus on direct interventions (e.g. use of chemicals), whilst others have largely considered indirect interventions (e.g. manipulation of age structures), and understanding of integrated approaches is patchy. There is an opportunity to gather together a guide to the different approaches – which could propose a typology and set of definitions of solutions that could be used by subsequent PHC communications; provide a basis for cross-sectoral dialogue; provide a basic mapping of how the solutions are currently used by sector; and help identify untested combinations of solution and setting which could be developed.

Impact: Improved understanding of concepts and options amongst stakeholder community in Scotland; a basis for gap analysis by PHC.
Project Lead: Sebastian Raubach
Plant health is a major issue worldwide with many different pests and diseases threatening different plant-based sectors, e.g. forestry, agriculture, environment and horticulture. Keeping up to date with such threats has always been a major task in terms of pest and disease identification, geographic spread, monitoring and coordinating responses etc. yet, in the world of mobile technology, we now have an opportunity to achieve some of these things from apps on our phones. Questions around the use of such technology include: What options are available in terms of mobile technologies for plant health?; What is their primary purpose?; Who are they targeted towards - farmers, plant health professionals, citizen scientists etc? Are they accurate and reliable? Do they provide real time information to a central database?; Who uses such a database?; Which sectors are they designed to work in or are they cross sector?; Do they have global use or are they limited to certain geographic regions? A review of such technologies is needed to ascertain which are most appropriate for use in Scotland across a range of sectors, which could be further adapted to achieve this aim and, if further development is required, what are the key elements of such a technology that would need to be incorporated into such a mobile application?

Impact: Improved risk assessment; better equipped stakeholders and government plant health officials; improved coordination of plant health activities in Scotland.

Publications

Forestry, Environment | Policy Document

Assessment of suitability for EAB invasion for Scotland and the UK

June 2021

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.

Forestry, Horticulture, Environment | Final Report and Policy Document

Metabarcoding analysis of Phytophthora diversity in spore traps and implications for disease forecasting in the P. ramorum management zone

May 2021

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.

Forestry, Horticulture, Agriculture, Environment | Final Report and Policy Document

PHC2020/09: Economic Impact of Pesticide Withdrawals to Scotland, with Case Studies

March 2021

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

November 2020

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

June 2020

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

May 2020

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.

 

Forestry, Environment | PHC Pest Review

Threat: Bud worm

Authors: Chris Quine
October 2019

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

Forestry, Environment | Final Report and Policy Document

Development of an online, user friendly plant health resource bank for the Scottish Natural Environment

August 2019

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.

Forestry, Horticulture, Agriculture, Environment | Final Report and Policy Document

The use of mobile technology to enhance plant health monitoring and awareness in Scotland

August 2019

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

Authors: Katy Hayden
September 2018

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.