Future Disease Risks in Tree Seedling Production: Pathogens, Climate Change, and Invasive Species

1. Future disease risks in tree seedling production NordGen 2018 Conference 18.9.2018 Anne Uimari Natural Resources Institute Finland Uimari

2. Content • Pathogens and diseases in tree nurseries • Invasive alien and emerging forest pathogens • Effects of climate change on tree (nursery) diseases • Disease prevention and plant protection • Summary Uimari

3. Pathogens and diseases in tree nurseries Gremeniella abietina Phytophthora cactorum Botrytis cinerea • A set a established common nursery diseases caused by fungi, oomycetes and bacteria (grey mold, scleroderris canker/brunchorstiadisease, birchleafspots and stemlesions, etc.) • someeconomiclossannually • pathogenabundancevaries (weather, othermicrobes, naturalhosts, etc.) • prevention byplantprotectionagencies and integratedpest management • Invasivealien and emergingpathogens Uimari

4. Invasive, alien, emerging species Invasive species = species accidently or inadvertently transported by the human actions into new area Alien species = introduced outside its natural past or present distribution Emerging species = already known organism (or a newly described species) whose incidence or geographical distribution is increasing notably Uimari

5. Invasive alien and emerging pathogens • Main pathway for introduction is global trade • Number of alien fungal species establishing annually has increased fourfold between 1900 and 2009 • Invasive species acting as tree pathogens are a major threat to forests and nurseries worlwide • In Europe the total annual costs are estimated ~ 10 billion € • Extent of the risks and putative damage often difficult to predict in the new environment Uimari

6. Invasive alien and emerging pathogens • Invasive pathogens known to be harmful to plants are listed in EU Directive 2000/29/EC (include the ”quarantine species”) • Harmful organisms followed by European and Mediterranean Plant Protection Organisation (EPPO) • A1 and A2 Lists: pests recommended for regulation as quarantine pests • Alert List: pests possibly presenting a risk • National lists of quarantine and harmful pathogens Uimari

7. Invasive alien and emerging pathogens https://www.researchgate.net/figure/Pitch-canker-symptoms-on-mature-pine-trees-a-plantation-of-infected-trees-showing_fig1_235444883 Fusarium circinatum(Gibberella circinata) Pinus spp. (plantations, nurseries, seed orchards) (EPPO A2) Phytophthora ramorum Quercus spp., conifers (Larix kaempferi, Picea sitchensis, Abies magnifica, A. grandis), nursery plants (Rhododendron, Viburnum) (EPPO A2) https://slideplayer.com/slide/8729752/ Neonectria neomacrospora Abies spp., Larix spp. (EPPO Alert list) Picture Anne Uimari Uimari

8. Reducing the risks of invasive pathogens (international agreements, EU legislation, national laws, etc.) *International Plant Protection Convention • Prevention of introduction • Phytosanitary Measures (ISPMs by IPPC*) • Regulation of wood packaging • Pest Risk Analysis (PRA) • Phytosanitary Certificate (EU, plant passport) • Early detection / monitoring • Surveillance in potential entry points and channels (e.g. plant nurseries) • Reporting and management • Eradication and prevention of spread Uimari

9. Reducing the risks of invasive pathogens • Presence of pathogenic species in traded plants difficult to observe • no disease symptoms • no quick detection/identification methods available • Often harmful organisms are unknown prior establishment • organisms are harmless in their native region • In the new range • plants having not evolved alongside introduced species have built up no natural resistance • no natural “enemies” present to control population sizes Uimari

10. Reducing the risks of invasive pathogens (research) - Sentinel plantations and sentinel nurseries COST FP1401 Global network of nurseries as early warning system against alien tree pest (Global warning) • Sentinel plantations (= exotic plants in exporting countries, botanic gardens and arboreta ) • Increase understanding about ‘known’ pests and diseases (e.g. dispersal mechanisms, origin, etc.) • Identify new pest-host associations (e.g. suggest which species of plant may be particularly susceptible/ resistant to a particular pest) • Identify potential biocontrols • Sentinel nurseries (= traded plants established in the region of export without phytosanitary treatment) • Assessment of potential pests transported by these commodities Uimari

11. Reducing the risks of invasive pathogens (puplic) Picture Risto Rikala • Public participation is important in early detection and monitoring • Public’s horticultural choices affect the trade → introduction of pathogens • Professional growers • domestic seedling production • detection and monitoring of invasive nursery diseases Uimari

12. Effects of climate change on tree (nursery) diseases Climatechange ~ changingtemperature and precipitation • Rangeshifts (expansion,reduction) of native and exoticpathogenspecies • Hostdistibution and response (susceptibility,resistance) to pathogens • Pathogen ”virulence” • Presence of neededcarriers / vectors • Interactionsbetweenpests / pathogens • Risksdifficult to predict • Climatemodeling and riskassessments Uimari

13. Plant protection • Plant protection: • Chemical agents, pesticides • Biological control methods • Biopesticides • Integrated pest management • Problems in chemical pesticide usage e.g. • safety (humal health, environment) • availability in market, areal restrictions • resitance development • new pest/pathogen species • increased need for safe and universal plant protection methods Uimari

14. Summary • Future disease risks and challenges for tree seedling production • The increased introduction of invasive and emerging forest pathogens • Multiple effects of climate change on pathogens and their hosts • Limited choice of effective plant protection methods safe for users and environment Uimari

15. Thankyou! Uimari