Forestry

The sector represents a major component of Scotland’s rural economy – providing significant employment and raw materials for wood processing industries. Sustainable forest management seeks to deliver these economic benefits alongside important ecosystem services such as carbon sequestration and flood mitigation, provision of wildlife habitat and opportunities for recreation and a range of leisure activities. Pests and diseases threaten the continued long-term delivery of these benefits.

The forest area of Scotland expanded during the twentieth century through the efforts of the Forestry Commission and private owners to develop a domestic wood supply and provide rural employment. A number of introduced species, such as Sitka spruce, were key to afforestation of marginal agricultural sites and now are central to the wood processing industry. Woodland now occupies approximately 17% of the land area of Scotland and provides 44% of the GB softwood harvest, producing about 1.5 million m³ of sawn softwood. Plant health threats to the forestry sector include a number of recently introduced pests and diseases (e.g. Phytophthora ramorum, pine tree lappet moth, ash die-back), on-going management of endemic ones (e.g. large pine weevil and Heterobasidium annosum) and risks of those yet to arrive (emerald ash borer, Ips typographus and many other organisms potentially introduced through trade in plants, wood and packaging).

Projects

Spatio-temporal modelling of great spruce bark beetle (Dendroctonus Micans) in Scotland

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.

Assessing spread of phytophthoras in Scottish forests by recreational and harvesting activities using comparative qPCR and metabarcoding techniques

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.

Using modelling to investigate the effectiveness of national surveillance monitoring aimed at detecting a Xylella fastidiosa outbreak in Scotland

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.

Potential impacts arising from pesticide withdrawals to Scotland’s plant health

Project Lead: Andy Evans

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. There is an urgent need to quantify the impact on Scottish plant health that will arise from pesticide withdrawal scenarios and to set this in the context and time frame of alternative management tools. This will be used to inform recommendations on pesticide strategy at the Scottish, UK and EU levels going forward. A synthesis report of available information is required to identify products at risk and work through scenarios for the plant types, pests and diseases of importance in Scotland. This will be a project where cross-sectoral dialogue between the plant health sectors of agriculture / crop production, horticulture, forestry and the environment will be necessary. The project will review existing information and a key output will be summary recommendations appropriate for use by policy makes. The bid must include time to engage with in cross-sectoral dialogue and with Scottish Government staff to discuss and progress early drafts.

Impact: Improved understanding of costs and benefits of pesticide use across Scottish sectors and an impact analysis for the most likely withdrawal scenarios such that key gaps can be identified and their impact quantified in order to inform pesticide policy.

Impact of climate change on the spread of pests and diseases in Scotland

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 stakeholders and government plant health officials to assess possible impacts of climate on pests and pathogens in Scotland.

Integration of Plant Health planning into the new Scottish Biodiversity Strategy

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).

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

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

Network analysis – where do people in Scotland get their plant health information?

Project Lead: Rehema White, Elliot Meador

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.

Sharing solutions between sectors: what methods are deployed in tackling pests and diseases?

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.

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

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.