Kauri Dieback Building Knowledge Review A review of operational research undertaken by the Kauri Dieback Programme from January 2009 to June 2020 and related research for biology, surveillance, vectors, control, and decision support Biosecurity New Zealand Technical Paper No. 2020/09 Prepared for the Kauri Dieback Programme by Karyn Froud, Biosecurity Research Ltd ISBN No. 978-1-99-004360-4 (online) ISBN No. 2624-0203 (online) October 2020 Disclaimer While every effort has been made to ensure the information in this publication is accurate, the Ministry for Primary Industries does not accept any responsibility or liability for error of fact, omission, interpretation or opinion that may be present, nor for the consequences of any decisions based on this information. This publication is available on the Ministry for Primary Industries website at – www.mpi.govt.nz/news-and-resources/publications/ © Crown Copyright – Ministry for Primary Industries Reference for citation: Froud, K J (2020) Kauri dieback building knowledge: Review of operational research undertaken by the Kauri Dieback Programme from January 2009 to June 2020 and related research for biology, surveillance, vectors, control, and decision support. A report prepared for MPI and the Kauri Dieback Programme by Biosecurity Research Limited. This work was commissioned by the Ministry for Primary Industries to produce a review of 10 years of operational research, in the context of other research, to describe: what we have done (current state), what we have learnt, what are the gaps and barriers and future lines of enquiry. Authored by: Karyn Froud Signed: Director, Epidemiologist Biosecurity Research Limited Contributed to and Travis Ashcroft, Ministry for Primary Industries reviewed by: Tony Beauchamp, Department of Conservation Chris Green, Department of Conservation Murray Fea, Auckland Council Yue Chin Chew, Auckland Council Kim Parker, Waikato Regional Council Gavin Clapperton, Northland Regional Council Jane Meiforth, Landcare Research (Remote sensing section) Jenny Heine, Editor Status: Final Report Revision / version: 1.1 Issue date: 31 October 2020 Use and Reliance This report has been prepared by Biosecurity Research Limited on the specific instructions of our Client. It is solely for our Client’s use for the purpose for which it is intended in accordance with the agreed scope of work. Biosecurity Research Limited does not accept any liability or responsibility in relation to the use of this report contrary to the above, or to any person other than the Client. 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Contents 1 Kauri Dieback Programme review objectives 7 2 Background 8 2.1 Kauri Dieback Programme research structure 8 3 Understanding the disease: origin, taxonomy, biology and impacts 10 3.1 Origin and taxonomy 10 3.2 Biology 11 3.3 Alternative hosts 12 3.4 Epidemiology 13 3.5 Impacts 18 3.6 Knowledge gaps for biology 20 4 Surveillance, kauri mapping, detection, diagnostics 21 4.1 Operational delivery of surveillance 21 4.2 Host population detection (kauri trees) 27 4.3 Pathogen detection 31 4.4 Kauri dieback (disease) detection 38 4.5 Surveillance test performance 41 4.6 Future surveillance and monitoring 44 4.7 Surveillance recommendations 45 5 Pathways and vectors 47 5.1 Overview 47 5.2 Human footwear vectoring 47 5.3 Kauri wood 49 5.4 Nurseries and forestry plantations 50 5.5 Animal vectors 52 5.6 Root-to-root transfer 56 5.7 Knowledge gaps for surveillance 57 6 Controlling the disease – phosphite, hygiene and oospore control, biological control, genetic resistance and/or tolerance 58 6.1 Phosphite 58 6.2 Hygiene and oospore control 66 6.3 Exclusion and track management 75 6.4 Biological control 75 6.5 Alternative treatments 76 6.6 Genetic resistance and/or tolerance 77 6.7 Knowledge gaps for control 78 7 Decision support 79 7.1 Mātauranga Māori and science plan 79 7.2 Prioritisation framework 79 7.3 Kauri geodatabase 81 7.4 Best practice guidelines 81 7.5 Decision support knowledge gaps 86 References 87 Appendix - Key knowledge gaps A3 table 96 Page | 5 Tables Table 3-1: Proposed criteria for confirmed, probable, suspect case and non-cases (unhealthy and non-cases) of kauri dieback ........................................................................................................... 15 Table 4-1: Kauri Dieback Programme surveillance activities and references to surveillance reports ................................................................................................................................................... 21 Table 6-1: Temperature and time heat–treatment results from Kauri Dieback Programme- funded and other research ................................................................................................................... 71 Figures Figure 3-1: Canopy symptom class and severity rating: 1) healthy crown with no visible signs of dieback; 2) canopy thinning; 3) thinning and some branch dieback; 4) severe dieback; 5) dead (Dick & Bellgard 2010). ......................................................................................................................... 16 Figure 3-2: Example of a causal diagram indicating potential and known interrelating factors that could contribute to kauri dieback ................................................................................................. 17 Figure 4-1: P. agathidicida distribution as of 10 June 2020, excluding private landowner data held at Auckland Council ....................................................................................................................... 23 Figure 4-2: P. agathidicida sampling locations as of 10 June 2020 (excluding Auckland Council data from 2015 onwards) ..................................................................................................................... 24 Figure 4-3: Flight paths of fixed wing aerial surveillance projects from 2011 to 2018 ........................ 25 Figure 4-4: Flight paths of fixed wing aerial surveillance projects from 2016 to 2019 ........................ 26 Figure 4-5: Southern distribution limit for naturally occurring kauri in New Zealand ......................... 29 Figure 4-6: Kauri dieback programme surveillance methods as at 2019.............................................. 33 Figure 4-7: Kauri dieback basal trunk lesion, showing ideal lesion excision points .............................. 35 Figure 4-8: Canopy thinning, a symptom of kauri dieback, caused by Phytophthora agathidicida .......................................................................................................................................... 41 Figure 4-9: Diagram of test performance showing tests with either 100 percent sensitivity or 100 percent specificity .......................................................................................................................... 44 Figure 5-1: Map depicting the main New Zealand Forestry Service kauri nurseries and distribution of kauri seedlings to plantation sites ................................................................................ 51 Figure 5-2: Evidence of pig wallowing next to a kauri tree ................................................................... 54 Figure 5-3: Evidence of pig damage to a kauri tree trunk .................................................................... 55 Figure 6-1: Image accessed from the piha.org.nz website showing where phosphite treatment trees are located in the Waitākere Ranges ........................................................................................... 65 Figure 6-2: Temperature versus time heat–treatment efficacy results ................................................ 73 Figure 7-1: Decision support framework flow chart showing the process from the different framework tabs in the Excel spreadsheet tool ..................................................................................... 81 Figure 7-2: Three times the dripline risk zone for kauri dieback .......................................................... 82 1 KAURI DIEBACK PROGRAMME REVIEW OBJECTIVES This document aims to: 1. review Kauri Dieback Programme- (KDP-) funded research in the following areas: a. understanding the disease – origin, taxonomy, biology and impacts; b. surveillance, detection, diagnostics and pathways c. controlling the disease – phosphite, oospore control; biological control; genetic resistance and tolerance; hygiene; d. decision support – kauri mapping, best practice guidelines, prioritisation