Detection and precautionary measures promoting best practice. Joan Webber, Forest Research, UK

Transcription

1 Detection and precautionary measures promoting best practice Joan Webber, Forest Research, UK ICF National Conference, 23 rd April 2015

2 Significant emerging threats 2012 Hymenoscyphus (Chalara) fraxineus 2012 Asian longhorn beetle 2011 Phytophthora austrocedri 2009 Acute oak decline 2011 Chestnut blight 2008 Douglas-fir seed bug 2010 Phytophthora lateralis 2007 Pine-tree lappet moth Context 2007 Phytophthora pseudosyringae 2006 Oak processionary moth 2004 Pseudomonas syringae pv aesculi 2003 Phytophthora kernoviae Horse chestnut leaf miner Gypsy moth 2002 Phytophthora ramorum 1982 Great spruce bark beetle 1997 Dothistroma needle blight 1972 Larch sawfly 1993 Alder Phytophthora But don t forget the old!

3 Biosecurity threats Detection how? Precautionary measures why? What have we learned? What you need to do - best practice for the sector

4 Detection Revolution in detection methods over 20 years But... We need the right samples Asymptomatic plants / trees, but where do we start? We find the DNA, but we don t have the organism. So what is the biological significance? Symptoms > culturing > field detection > DNA > PCR (amplify diagnostic genes)

5 P. ramorum affecting larch May 2012 Loch Trool May 2013 Loch Trool

6 Precaution Precautionary measures how and why? Trees have long life cycles and evolve over millennia Pests and pathogens have rapid generation times and change very quickly think of an arms race Early detection of new threats in the wider environment is often difficult And eradication even harder Outcomes are unpredictable x

7 x Newly arrived organisms change? Fitness traits Selection components!! POW WHAM! ZAP Hybridisation Introgression Sex 2ry introductions Mutation Genetic bottleneck After Brasier, 1987

8 Impact of invasives in natural environment vs agricultural systems E Im Impact A Im Years Waage et al x How long is this phase?

9 DNB in Britain Initially confined to cases on Corsican pine outbreaks 3 in nursery stock, Dorset 1 in south Wales outbreak south Wales outbreaks 7 out of 25 forest blocks affected in East Anglia FD

10 Learning curve Understanding the risk Risk to different trees hosts New to science, then risks are unknown New to the UK, then risks often better known Native/endemic host combined with new pest or native/endemic pest combined with non-native tree species Mechanisms of spread and biosecurity implications Soil borne, water borne, wind borne Active spread with insect pests, or insect vectored diseases

11 Learning curve - hosts Holm oak Magnolia Rhododendron

12 Learning curve - spread People movement of Phytophthoras 70 Incidence of Phytophthoras, Other Phytophthoras P. kernoviae 60 Percentage of samples June- July Aug- Sept Oct-Nov Dec-Jan Feb- March April- May June- July Aug- Sept Oct-Nov

13 Learning curve - spread Spore release of Hymenoscyphus fraxineus Early in the morning peaking between 6-8 am during summer Spore numbers at night Spore numbers at 5am Spore numbers at 7am Work of Halvor Solheim, Volkmar Timmermann & Isabella Berja, Skog og Landskap, Norway

14 Learning curve - spread Spread of insect pests Asian longhorn beetle Life cycle of 2 to 3 years Slow spread, although can fly >370 m Movement in wood packaging material or plants In UK, infestation may have been established for 8 years before discovery Emerald ash borer Life cycle of 1 to 2 years Fast spread, can fly 1 km, but up to 10 km after emergence Movement in firewood or wood packaging material

15 Probabilities of dispersal Localised spread from affected trees Probability of Dispersal Local microclimate, topography and human activity Plant movement, human activity, weather events? Distance from source

16 Long distance spread

17 Best practice Communication and raised awareness Can we afford to return to old practices Consider what might come with extra risk because of uncertainty Selection of plants it s not just about species and size? Plant sources where do they come from and how does this equate to changing pest and pathogen distributions? Past performance can only be a guarantee of future low risk if nothing changes Keep up to date, knowledge changes eg DNB dispersal distances

18 Best practice Best practice in operation and in the forest AgriPlant Ltd Machinery moves from location to location it may be a vector! Forest roads and construction? Moving large trees, swapping material the downsides? Examples include P. ramorum, P. kernoviae and elm yellows There can be solutions Phytophthora ramorum network of licensed mills to process affected material in line with biosecurity requirements

19 Best practice New tools Forest Research tree Health Advisory service Consider a wider range of silvicultural systems and tree species, less dependency on single species Maybe even revisit the old species But don t forget old foes! Rhizophagus grandis to combat the great spruce bark beetle PG Suspension and urea stumps treatments against root and butt rot, and a DSS on when / where to treat DSS for Hylobius and plant treatments

20 Funding & partnerships