Dactylanthus taylorii recovery plan, 2004–14 THREATENED SPECIES RECOVERY PLAN 56 Published by Science & Technical Publishing Department of Conservation PO Box 10–420 Wellington, New Zealand Cover: Dactylanthus taylorii tuber with a bud, on a plant established from seed in a seeding trial at Waipapa. Photo: Avi Holzapfel Compiled by: G.D. La Cock, S. Holzapfel, D. King, and N. Singers Individual copies are printed, and are also available from the departmental website in pdf form. Titles are listed in our catalogue on the website, refer http://www.doc.govt.nz under Publications, then Science and research. © Copyright October 2005, New Zealand Department of Conservation ISSN 1170–3806 ISBN 0–478–14027–4 This report was prepared for publication by Science & Technical Publishing; editing by Helen O’Leary and layout by Ian Mackenzie. Publication was approved by the Chief Scientist (Research, Development & Improvement Division), Department of Conservation, Wellington, New Zealand. In the interest of forest conservation, we support paperless electronic publishing. When printing, recycled paper is used wherever possible. Contents Abstract 5 1. Introduction 6 1.1 Terminology 6 2. Ecology and biology of Dactylanthus taylorii 7 3. Cultural importance 8 4. Past and present distribution 8 5. Threats and agents of decline 9 6. Past and current management 9 7. Public awareness 10 8. Status and species recovery principles 10 9. Options for recovery 11 9.1 Option 1—do nothing 11 9.2 Option 2—undertake national priority work 11 10. Recovery vision and goals 11 10.1 Vision 11 10.2 Goals 11 10.2.1 Long-term goal (50 years) 11 10.2.2 Short-term goal (10 years) 12 11. Implementation of the work plan 12 12. Work plan 12 12.1 Theme 1: management 12 12.1.1 Topic 1: Planning 12 12.1.2 Topic 2: Survey 13 12.1.3 Topic 3: Legal protection and other legal matters 14 12.1.4 Topic 4: Threat management 14 12.1.5 Topic 5: Monitoring 15 12.1.6 Topic 6: Translocation 16 12.1.7 Topic 7: Ex-situ cultivation 17 12.1.8 Topic 8: Experimental management techniques 18 12.2 Theme 2: working with the community 18 12.2.1 Topic 1: Tangata whenua 18 12.2.2 Topic 2: The community 19 12.2.3 Topic 3: Private landowners and land managers 21 12.3 Theme 3: research 21 12.3.1 Topic 1: Agents of decline 21 12.3.2 Topic 2: Taxonomy and genetics 22 12.3.3 Topic 3: Autecology and population dynamics 23 12.3.4 Topic 4: Ecosystem 23 12.3.5 Topic 5: Social 24 13. Plan term and review date 24 14. Acknowledgements 24 15. References 25 Appendix 1 Putative hosts for dactylanthus 27 Appendix 2 Sites of national importance for dactylanthus 28 Dactylanthus taylorii recovery plan, 2004–14 THREATENED SPECIES RECOVERY PLAN 56 ABSTRACT Dactylanthus taylorii (dactylanthus) is an endemic parasitic flowering plant threatened with extinction. A review of the 1995 Dactylanthus taylorii Recovery Plan recommended that the Dactylanthus Recovery Group be maintained, and that a revised plan be produced for the period 2004–14 (this plan). The main objectives of the original plan were survey, protection, advocacy, and research on the propagation, genetics, ecology and protection of dactylanthus. This revised plan reflects the progress made by the group, with the focus shifting to improved management of threats, management of the habitat and ecosystems rather than just dactylanthus and its hosts, and the establishment of new populations or enhancement of existing populations. Long-term goals are identified, and the short-term actions and research needs required to meet these goals are outlined. Keywords: Dactylanthus taylorii, Balanophoraceae, parasitic flowering plant, wood rose, New Zealand © October 2005, Department of Conservation. This paper may be cited as: Department of Conservation. 2005: Dactylanthus taylorii recovery plan, 2004–14. Threatened Species recovery plan 56. 30 p. Threatened Species Recovery Plan 56 5 1. Introduction Dactylanthus taylorii Hook f. is the only fully parasitic flowering plant endemic to New Zealand. A member of the mainly tropical family of Balanophoraceae, it lives underground attached to the roots of a number of native tree and shrub species, where it forms a characteristic distortion on the host root in the area of attachment (the ‘wood rose’). In late summer to autumn, each plant produces inflorescences filled with nectar which grow just above the forest floor. Dactylanthus taylorii is considered dioecious, as it usually produces male and female inflorescences on different individuals. The endemic short-tailed bat (Mystacina tuberculata) is so far the only confirmed native pollinator. Kiore (Rattus exulans), mice (Mus musculus) and introduced ship and Norway rats (R. rattus and R. norvegicus) have been shown to be introduced pollinators, though rats often destroy flowers rather than pollinating them. The Department of Conservation (DOC) formed a Recovery Group for D. taylorii (Molloy 1993) because of concerns which included: its observed failure to reproduce due to browsing of the inflorescence by introduced animals (possums and all species of rats, including kiore); an apparent decline in distribution over the last 50 years; and ongoing destruction of specimens by wood rose collectors. A recovery plan was published in 1995 (Ecroyd 1995). This plan had a term of 5 years. In accordance with the Standard Operating Procedure for species recovery (Brown & Molloy 1999) a decision was made by the Recovery Group to review the achievements to date to help with recommending further planning requirements (Anon. 1999). This review (Holzapfel in press) recommends that a new recovery plan be prepared for dactylanthus, and that the Recovery Group be maintained. The Recovery Group has accepted ‘dactylanthus’ as the common name for the species. The recovery planning process provides opportunities for further consultation between the Department, tangata whenua and others regarding management of this species. Those interested in being more involved in management of dactylanthus or in receiving information should also contact the Recovery Group. 1.1 TERMINOLOGY Clump(s): Several individual dactylanthus plants attached to roots in close proximity to each other usually manifest themselves as a clump on the surface of the ground. It is virtually impossible to separate individual plants within these clumps, therefore ‘clumps’ will be used to refer to these aggregations throughout the plan. Conservancy(ies): For the purposes of this plan ‘conservancy’ is used in the inclusive sense, and covers work to be done within a conservancy by conservancy and / or area office staff. 6 Dactylanthus taylorii recovery plan, 2004–14 2. Ecology and biology of Dactylanthus taylorii Dactylanthus taylorii is a forest root parasite consisting of a round warty tuber up to 40 cm in diameter1 attached to the root of a host tree or shrub. In re- sponse to an infection by dactylanthus, the area of host root at the attachment site enlarges into a finely grooved disk (the wood rose). Dactylanthus obtains its nutrients from the host plant through this attachment. It has no green leaves or roots of its own. Currently it is known to parasitise about 30 species of native trees and shrubs. Many of these host species are seral and found mainly on for- est margins or disturbed areas. Mahoe, lemonwood, lancewood, kohuhu, wineberry, broadleaf, fivefinger, pate, karamu and putaputaweta are common hosts (see Appendix 1 for a full list of host species plus their scientific names). It is not known to parasitise non-native species, gymnosperms or monocotyl- edons. Dactylanthus tolerates a wide range of environmental conditions but its optimal habitat appears to be damp but well-drained sites. Plants are found from near sea level at East Cape to around 1200 m a.s.l. (see Moore 1940; Ecroyd 1996; Holzapfel 2001 for more detail). Dactylanthus is considered to be dioecious, with inflorescences containing both male and female flowers being extremely rare. Male plants are significantly more common than females and at some sites the sex ratio can be as high as 20 : 1. There is some indication that newly established plants produce predominantly female flowers (S. (Avi) Holzapfel, DOC, pers. obs.). The minute flowers are clustered into inflorescences that emerge from the tuber and contain either male or female flowers on several spadices (stalks approximately 2 cm long, covered with flowers). Flowering usually starts in February and extends to May, with the peak in March and April. Male flowers seem to appear before females, and last about 10 days. Female flowers are receptive to pollen for about 10 days. Once pollinated the flowers mature and the spadices gradually elongate. Each inflorescence is capable of producing thousands of seeds with an average of 3600 per inflorescence. Female inflorescence production is variable depending on size. A large female plant is capable of producing over 50 inflorescences in a season. Seed matures over the next 6 months, may remain on the plant for up to 4 years and may be viable for up to 7 years. Seed is small (approximately 1.6 × 1.1 mm), ovoid to spindle shaped, and enclosed in a hard black endocarp. It has a short-lived, thin but fleshy ectocarp layer which degrades as the seed matures (Ecroyd 1995). The short-tailed bat is the principal native pollinator but its current range only overlaps with dactylanthus at a few sites. Rats and mice now largely perform this function though lizards and insects may also play a small role. Dactylanthus has features typical of bat-pollinated flowers, e.g. large, dull-coloured, robust, bowl shaped flowers which produce large quantities of musky smelling nectar (Ecroyd 1995). 1 This is probably only true for aggregates (clumps). Individual plants will be fist-sized to perhaps soccer-ball sized at most.