Vascular flora of Motuora Island, Hauraki Gulf Shelley Heiss-Dunlop & Jo Fillery Introduction 1988). A total of 141 species (including 14 ferns) were Motuora Island lies in the Hauraki Gulf southwest of recorded. Exotic plants confined to the gardens Kawau Island, approximately 3km from Mahurangi around the buildings at Home Bay were not included Heads, and 5km from Wenderholm Regional Park, in Dowding’s (1988) list. Dowding (1988) commented Waiwera. This 80ha island is long and narrow on four adventive species that were “well-established” (approximately 2km x c. 600m at its widest) with a and that “may present problems” (presumably for a relatively flat top, reaching 75m asl. The land rises future restoration project). These species were abruptly, in places precipitously, from the shoreline so boneseed (Chrysanthemoides monilifera), boxthorn that the area of the undulating ‘level’ top is (Lycium ferocissimum), gorse (Ulex europaeus) and comparatively extensive. Composed of sedimentary kikuyu grass (Pennisetum clandestinum). All four strata from the Pakiri formation of the Waitemata species still require ongoing control. However, as a Group (Lower Miocene age, approximately 20 million years old), Motuora is geologically similar to other result of ongoing weed eradication endeavours, inner Hauraki gulf islands such as Tiritiri Matangi, boxthorn has been reduced to a few isolated sites, Kawau, Waiheke and Motuihe Islands (Ballance 1977; and boneseed once widespread on the island is Edbrooke 2001). considerably reduced also, occurring in high densities now only on the northern end of the island (Lindsay History 2006). Gorse and kikuyu are controlled where these Motuora Island was farmed, from as early as 1853 species inhibit revegetation plantings. (Hawley and Buckton 1987). The Hauraki Gulf Maritime Park Board purchased the island in 1966, Dowding (1988) noted that some native species were and it has been administered by the Department of represented by only a few specimens and in the case Conservation (DoC) since 1987. By 1988 Motuora of kohekohe (Dysoxylum spectabile), puriri (Vitex Island’s future as an open sanctuary was gaining lucens) and karaka by only a single specimen. The favour (Dowding 1988). The island was free of puriri has since died, and although the mature mammalian pests, but the natural habitat was kohekohe has not been seen to produce fruit there severely depleted. In 1990 members of the local are juvenile kohekohe present on the island (Helen community led by the Mid-North Branch of the Royal Lindsay pers. comm.). Forest and Bird Protection Society and supported by DoC began replanting the island. Today the island is The vascular flora list for the island was updated in jointly managed by DoC and the Motuora Restoration 1997 as part of the Motuora Restoration Working Plan Society (Inc) which was formed in 1995. document. Twenty-nine species were added to Dowding’s 1988 listing (Hawley and Buckton 1997). Past vegetation There are few records on the vegetation history of Vascular flora survey 2006 Motuora Island. Much of the original vegetation was A further update of the list was required this year for most likely burnt during Maori occupation or visitation, the development of the Motuora Species Translocation as with most northern offshore islands (Atkinson Plan 2006-2017 (Gardner-Gee et al. 2006). Early in 2004; Wright 1988). During the early 1900’s the the year (31/01/06-04/02/06 and 30/04/06) we remaining vegetation was cleared back to the cliff undertook a survey of the island’s vascular flora. edges and replaced with pasture by European Species found during that survey are recorded in farmers. Stock evaded the cliff top fences, and Appendix 1, including an additional ten species invasive species such as climbing asparagus identified during weed survey work later in the year (Asparagus scandens) and boneseed (06/11/06-11/11/06). A total of 288 taxa have been (Chrysanthemoides monilifera) began out-competing recorded, of which 123 (43%) species are native, 165 native plants on the cliffs. So even the cliff faces (57%) are exotic, and of which 138 taxa are additions represent a significantly modified environment where to previous listings (Table 1). ‘Exotic’ additions are regeneration patterns have been disrupted and comparatively high (88 taxa) because garden relics species composition altered, and in some areas the growing around Home Bay have been included in a remaining vegetation is so minimal that it reveals little floral survey for the first time. about the vegetation that existed before human settlement. Twenty-two taxa recorded by Dowding (1988) and Hawley and Buckton (1997) were not located during Previous vascular flora surveys our survey. Of these, ten are native. With further The first vascular flora listing for Motuora Island was searching five of these natives; coprosma hybrid incorporated in an ornithological survey report (Coprosma macrocarpa x C. propinqua), Geranium compiled during three visits to the island in August solanderi, native fireweed (Senecio hispidulus), 1987, October 1987, and April 1988, by members of nertera (Nertera sp.) and true maidenhair (Adiantum the Ornithological Society of New Zealand (Dowding aethiopicum) may possibly be located. The other five 113 species; dwarf cabbage tree (Cordyline pumilo), Glen Cattle were maintained on the island up until February Murray tussock (Carex flagellifera), pigweed (Einadia 2006 to manage pasture not yet retired for planting. trigonos), tawapou (Pouteria costata) and thin-leaved Approximately 30ha of retired pasture have now been coprosma (Coprosma areolata) are most likely now planted by early successional species and it is extinct on Motuora and are to be considered for anticipated another 25ha will be planted by 2010 future re-introduction. (Gardner-Gee et al. 2006). Ten introduced species recorded in previous listings Revegetation (Dowding 1988; Hawley and Buckton 1997) can also Over 205,000 trees have been propagated and be considered extinct from Motuora. These include planted since 1990. Initially seed was sourced from hedge privet (Ligustrum ovalifolium), cotoneaster the island where sufficient genetic diversity remained. (Cotoneaster franchetii), false acacia (Robinia Local seed sources included akeake (Dodonea pseudoacacia), hemlock (Conium maculatum), ivy viscosa), broom (Carmichaelia australis), hangehange (Hedera helix), juniper (Juniperus sp.), lemon scented (Geniostoma ligustrifolium), houpara, karamu jasmine (Jasminum azoricum), purple guava (Psidium (Coprosma robusta), karo, mahoe (Melicytus cattleianum), purple nut sedge (Cyperus rotundas) ramiflorus), ngaio (Myoporum laetum), pohutukawa, and tamarisk (Tamarix sp.). puriri, taupata (Coprosma repens) and whau (Entelea arborescens). However there were, initially, only a Of all the exotics with ‘new-listing’ status only two few akeake, cabbage tree, coastal kowhai (Sophora stand out as almost certain recent arrivals (since chathamica), flax (Phormium tenax), five-finger 1997); the invasive holly fern (Cyrtomium falcatum) (Pseudopanax arboreus), hebe (Hebe stricta and H. and Chinese privet (Ligustrum sinense). The other macrocarpa), manuka (Leptospermum scoparium), exotics in this category were either deliberately and a single mature karaka (Corynocarpus laevigatus) ignored (garden plants) in earlier surveys or could remaining on the island. Some seed was collected have possibly been missed. from these specimens but much of the seed for these species was sourced from Tiritiri Matangi during the We identified sixteen more indigenous fern species early years of restoration. Kanuka (Kunzea ericoides) than previously recorded. Some of these might be and wharangi (Melicope ternata) being absent from recent arrivals, but most could well have been present the island were also sourced from Tiritiri Matangi. It is on the island in 1997 in low numbers in remote intended in the future to source additional seed from locations. As revegetation has advanced suitable fern Mahurangi East and West, and Wenderholm (Gardner- habitat has increased (particularly in the earliest Gee et al. 2006). planted areas such as Macrocarpa Bay), and ferns are becoming more widely established. There have been very few natural introductions of woody plant species (native or exotic) since the outset Current vegetation of the project suggesting there is very little bird Native forest remnants (mainly pohutukawa) are movement between Motuora, the mainland and scattered around the outer perimeter of the island nearby islands. The introduction of a wider range of comprising approximately 20 ha. A remnant on the late-successional trees is planned to provide the east-facing slopes of Pohutukawa Bay provides the variety and quantity of food sources that will attract best representation of naturally regenerating coastal and maintain populations of birds like kereru, bellbird forest on the island. Typical coastal species are and kakariki. present, dominated by pohutukawa (Metrosideros excelsa), karo (Pittosporum crassifolium), houpara The restoration goal of Motuora Island is to re- (Pseudopanax lessonii), coastal karamu (Coprosma establish self-sustaining ecosystems and to create a macrocarpa), kawakawa (Macropiper excelsum), sanctuary for endangered flora and fauna. As a coastal astelia (Astelia banksii) and rengarenga measure of progress Motuora has operated as a ‘kiwi (Arthropodium cirratum). creche’ for the Operation Nest Egg programme since 1999, currently maintaining a population of around 50 On