4. Management of climate-change impacts on plant health

National plant protection organizations need to prepare for, and be able to respond to, the presence of non-native plant pests that have been introduced with trade or by natural migrations. In the case of some pests, the introduction may be predictable because the pests have been introduced in previous years or to neighbouring countries, but in other cases the introduction may be the result of a less predictable intercontinental movement of a pest. Climate change adds to the unpredictability of pest introductions, because it can change the probability of a pest arriving or surviving, and this increases the need for activities to enhance preparedness.

The surveillance, monitoring and response to a pest affected by climate change is essentially the same as that to any pest of concern. What is different is what happens before: the previous steps that determine that these species, which in the past would not have been considered as needing a response because of unsuitable climates, are now part of the suite of species that need to be considered, as changing climate conditions imply that climates now (or in the near future) will be suitable.

Pest surveillance and monitoring ³

Plant-health surveillance and monitoring are important tools to detect the introduction of new pests or to monitor their status. Climate change means that there is a need for national, regional and international surveillance and monitoring activities for plant-health threats to be intensified. Consideration should be given to the development of model templates for multilateral surveillance programmes, especially for developing countries, to demonstrate how such programmes may be set up to offset phytosanitary threats (IPPC Secretariat, 2021a). One example of a survey template is found in Regulation (European Union) 2016/2031 (Articles 22, 23, 24) of the European Parliament (European Union, 2016), but other templates may also contain model approaches that determine risk locations based on environmental, anthropogenic or other factors to determine optimal survey locations and time periods. Also, tools to ensure statistically sound surveillance can be of help, such as the European Food Safety Authority’s Risk-based PEst Survey Tool – RiPEST (Bemelmans, 2023)

Surveillance and monitoring for pests potentially affected by climate change at the national and often regional level supports early detection of newly introduced pests as well as timely and effective control and eradication actions. The earlier a pest is detected after introduction, the greater the likelihood that eradication measures will be successful. Hence, surveillance and monitoring need to be key components of a strategy to assess and manage the introduction of pests potentially affected by climate change (FAO, 2008).

National plant protection organizations will need to consider climatic variability caused by climate change in the design and implementation of surveillance and monitoring programmes (IPPC Secretariat, 2021a). As stated in ISPM 6 (Surveillance), the suitability of the climate and other ecological conditions in the area for the pest is one of the factors that may determine the areas or sites selected for surveillance. The changing climate brings with it changing levels of risk of different pests; therefore, NPPOs and RPPOs need to keep under review the list of pests for which they survey.

Surveillance

Surveillance is an official process whereby information on pests in an area is obtained through general surveillance, specific surveillance or a combination of both (ISPM 5 (Glossary of phytosanitary terms)). Useful references on the requirements for surveillance include ISPM 6 and the IPPC Surveillance guide (IPPC Secretariat, 2021b).

A detection survey is a survey conducted to determine the presence or absence of pests (ISPM 5) in an area. Conducted regularly, detection surveys aid in the rapid identification of individuals or populations of pests that have been introduced through accidental means or natural spread or as a consequence of climate change. Detection surveys for pests potentially affected by climate change can be conducted by collecting samples by trapping, making visual inspections or sampling latent hosts.

Trapping surveys should be conducted in areas where the pest has not been detected before but might establish or in areas where migratory populations are expected to occur (IPPC Secretariat, 2021c). Research on pest biology and response to climate change, as well as modelling or forecasting to identify where the pest might establish, may be used to inform where and when to survey (e.g. Grünig et al., 2020; Kean and Stringer, 2019; Taylor et al., 2019). Surveys in such areas may be complemented by surveillance in areas with susceptible hosts. Where pest introduction is thought to be most likely to occur as a result of human action such as travel or trade, surveys should focus on points of entry of travellers and freight. Where natural spread or introduction of a pest as a consequence of climate change is thought to be most likely, surveys should focus on areas bordering or closest to any country known to be infested. One example of international guidance for surveillance is the European Food Safety Authority’s series of pest survey cards. This advice is intended to help European Union member states plan surveys for quarantine pests (EFSA, n.d.).

Along with detection surveys, information on pests potentially affected by climate change may be gained through general surveillance. General surveillance is a process whereby information on pests of concern in an area is gathered from various official or non-official sources (ISPM 6). One of those sources might be a citizen-science initiative coordinated to encourage the general public and stakeholders (e.g. growers, importers) to look out for pests potentially affected by climate change. Other sources include scientific publications and websites and social-media sites, such as the Global Biodiversity Information Facility, ⁴ that collate records of the detection of pests. Simple pest factsheets and identification resources (e.g. on fall armyworm (Spodoptera frugiperda) or Fusarium oxysporum f. sp. cubense Tropical Race 4) may be distributed to encourage people to report suspected pest detections to plant-health authorities (see IPPC Surveillance and reporting obligations e-learning course: elearning.fao.org/course/view.php?id=824 ).

Protected natural areas typically have monitoring programmes that can be integrated into wider national programmes to broaden the likelihood of detection of new incursions (Dalton et al., 2023).

Response plans

A response plan sets out the phytosanitary measures that are to be applied to contain or limit the spread of invasive pests once they are officially detected and confirmed. These include delimiting surveys, preventive measures, phytosanitary measures and measures to suppress the pest population and its spread (if feasible). A response plan should be implemented immediately once a pest that is potentially affected by climate change and poses an unacceptable pest risk is officially found in a new territory. The prevention and preparedness plan should also continue to be implemented for the parts of the country where the pest is still absent.

Key components of a response plan may include the following:

To ensure a rapid and effective response to an outbreak, it is advisable to carry out simulation exercises. These exercises, based on a hypothetical situation, are a preparation for real action in case of an outbreak. They help to improve workflows and are a good tool by which to identify important infrastructure, responsibilities, missing information, flaws in the system, necessary financial resources, and other important factors that should be considered.

For more information, see Emergency Preparedness – A Guide for Developing Contingency Plans for Outbreaks of Quarantine Pests (IPPC Secretariat, 2023): doi.org/10.4060/cc4820en

Suppression

Suppression is the application of phytosanitary measures in an infested area to reduce pest populations (ISPM 5). Phytosanitary measures include legislation, regulation or official procedures. Improving host-plant resistance to pests and competitiveness with pest plants, along with adjustments to pesticide application, are considered effective ways of adapting plant protection to future climatic conditions (Juroszek and von Tiedemann, 2015).

Integrated pest management is the preferred overall approach for suppression, but different methods will be appropriate in different situations. Choosing which method to use, and where and when to use it, at national, local or farm level, is critical to effective integrated pest management. In order to meet the phytosanitary import requirements of trading partners, a systems approach may be appropriate, as detailed in ISPM 14 (The use of integrated measures in a systems approach for pest risk management).

Any suppression method being considered for use can be evaluated against several criteria: cost-effectiveness, effectiveness, safety, availability and scalability.

Adaptation

The application of many pest-management measures, such as the application of plantprotection products, is generally less viable in forestry than in agriculture because of costs, impacts to non-target organisms and practical considerations. Therefore, adaptation to respond to potential climate-change effects is most likely to involve preventive measures, such as removing infested trees to avoid further spread of pests (Bonello et al., 2020; Liebhold and Kean, 2019). Another major preventive adaptation is the choice of suitable tree species, or pest-resistant or tolerant clones or cultivars if available, when new forests are planted (Bonello et al., 2020; IPPC Secretariat, 2021a). Given that managed forests are generally planted for a number of decades, foresters need to consider factors including the suitability of the planting site, the species and clones planted and other silvicultural factors in the knowledge that there is likely to be considerable change in the climate over the lifetime of the trees.

Indigenous Peoples

Indigenous Peoples have a long history of adapting to challenges in changing environments and their resilience strategies can help enrich and strengthen other adaptation efforts. Indigenous People’s knowledge provides a basis for the successful understanding of responses to, and governance, of climate change risks. For example, terrestrial and aquatic ecosystems in lands managed by Indigenous Peoples are often less degraded than other managed lands as a result of resource-use practices and ecosystemstewardship strategies that protect and foster biodiversity (IPCC, 2022b).

Recognizing and engaging with Indigenous Peoples to integrate alternative worldviews and traditional knowledge is needed at all levels of a country’s biosecurity system,⁵ including preparedness.

Integration of Indigenous People’s knowledge at all levels will enable co-management of responses, recognizing the rights of Indigenous Peoples to protect their environmental resources and uphold their responsibilities towards the natural world and the use of traditional knowledge.

International cooperation and capacity building

As pest management by one country may affect another, and pests can cross borders, international cooperation will be essential to the success of countries in adapting pestmanagement strategies to climate change (IPPC Secretariat, 2021a). The cooperation can take the form of promptly reporting the presence of new pests (ISPM 8 (Determination of pest status in an area)), sharing PRAs and knowledge on the use of climate models to predict pest status, or sharing resources and expertise (e.g. the National Regulatory Control Systems published by EPPO (n.d.(a)) on how to combat a particular pest. National plant protection organizations that have experience of managing a novel pest are likely to have useful experience to share with countries that may have outbreaks in future years. International cooperation may be global (e.g. via IPPC mechanisms) or regional (e.g. via RPPOs). For example, Carvajal-Yepes et al. (2019) have proposed a global surveillance system for crop diseases. This system would extend and tailor established phytosanitary and networking practices to developing countries, enabling quick responses to unexpected disease outbreaks and ultimately stabilizing and enhancing global food production. The global surveillance system would consist of existing surveillance systems around the world, linking general and specific surveillance activities across countries, and increasing coordination in pest detection, response and control.

Countries may build their capacity to cope with, and adapt to, climate change in various ways. For example, an IPPC phytosanitary capacity evaluation may be used to assess a country’s readiness to respond to plant diseases. Irrespective of whether or not climate change occurs as scenarios predict, enhancing capacity will have benefits and is likely to also result in cost–benefit improvements (IPPC Secretariat, 2021a). Enhancing adaptation capacity also means finding ways to manage financial risk under climate-change stresses. Crop insurance may be an option in some cases, but it does not necessarily protect productivity and may encourage continued production of crops where they are no longer suited to the environment (Di Falco et al., 2014; IPPC Secretariat, 2021a).

For more information, see The Global Action for Fall Armyworm Control (FAO, 2022) — doi.org/10.4060/cb8910en — and Recommendations for an Effective Pest Outbreak Alert and Response System (IPPC Secretariat, 2022): https://assets.ippc.int/static/media/files/mediakitdocument/en/2022/03/POARS_All_Recommendations.pdf

Communication and awareness

Communication is a critical element in assessing effectively pests that are potentially affected by climate change, once their presence has been detected. The IPPC Guide to Pest Risk Communication (FAO, 2019) — www.ippc.int/en/publications/90623/ — and the IPPC guide on Managing Relationships with Stakeholders (IPPC Secretariat, 2015) — www.ippc.int/en/publications/90634/ — provide guidance to NPPOs on identifying and engaging with stakeholders and on developing pest risk communication strategies, including guidance on the key goals and concepts of pest risk communication, the factors that may influence its success and the principles of good pest risk communication.

National plant protection organizations are encouraged, even when pests potentially affected by climate change are still absent, to publish their pest prevention, preparedness and response plans on their websites and communication platforms (Facebook, LinkedIn, Twitter, etc.)

Stakeholder-awareness programmes, particularly for farmers and growers, are also beneficial. Such programmes should include information on how to identify pests potentially affected by climate change, what should be done if these pests are suspected, how to report to the NPPO, and other relevant information that might be required. For example, the NPPO of Australia (Department of Agriculture, Fisheries and Forestry) has developed communication and awareness materials to meet different stakeholder needs for the top 40 priority pests, including pests potentially affected by climate change. These materials include: NPPO information (e.g. on nationalresponse); jurisdictional information to farmers and industry on surveillance, management and pest reporting; and industry information (resources and reference materials to support their specific activities). The EPPO region host an online platform for publicity material, with materials for many of the pests relevant to the region (EPPO, n.d.(b)), that NPPOs may also find useful when developing communication and awareness materials.

Examples of communication material related to the impact of climate change on plant health include: