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

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 stakeholders 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.
Project Lead: Kevin Watts
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 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.
Project Lead: Kirsty Park
Xylella fastidiosa is a bacterial plant pathogen that can cause disease in a broad range of hosts, including Polygala myrtifolia, Olea europaea, Rosmarinus Officinalis, Lavandula sp., Prunus sp. and Nerium oleander. 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. The bacteria are transmitted by xylem feeding insects from the Cercopidae family, which include froghoppers and spittlebugs.

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
in Scotland.

Publications

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.