Stating the Obvious

So, you go shopping for an island for conservation purposes and buy one. Why? Then what?

To answer the why,

I suppose we had gained some experience of how species and restoration projects went, and figured that we were capable of taking one on for ourselves.

As funders, we had been happy with the way DOC-led species projects on the public estate had gone, and we were learning something from the people who ran the projects. There were a few outstanding successes. Applications began to dry up though, perhaps because we had taken care of the ready-to-go projects and those remaining were too nebulous or expensive, or both, that they didn’t suit us. I tend to conclude though that DOC had had the stuffing knocked out of it by endless restructuring, and people were too busy polishing their resumes or reapplying for their own jobs to do anything. Whatever the reason, the money we had earmarked for conservation was going unspent.

We were also learning about ecological restoration projects, especially through our involvement as volunteers on publicly-owned Mana Island. The model of a community group working with the government did not suit me though. The volunteer workforce was looked on by some DOC staff as a group which could be used to tick the required community engagement box, but was otherwise just a nuisance to be kept at arm’s length. Conversely the volunteers ranged from brilliant to useless, and those who thought the project was a holiday and the DOC rangers were there to entertain them, annoyed the heck out of me.

Having established that I was too difficult and demanding to fit in anywhere else, and also for positive reasons, we started thinking about our own project. Although I am well qualified in one scientific field, it would be a mistake to think that I could branch out and offer anything in the threatened species area as, say, a captive-breeder, researcher or research manager. However, there were templates available for ecological restorations and we figured it was realistic to attempt one with the right team in place.

A mainland sanctuary project was considered and rejected pretty much straight away. Simple preservation of an area of forest through purchase and covenanting did not cut it. In the presence of predators, even mainland ecosystems covered in natural vegetation are little more than biodiversity deserts, despite looking pretty and attracting public attention such as the recent crowd-funded purchase of a beach in the upper South Island, laudable as a statement about land alienation but achieving little for conservation.

The next step up, the predator-reduced, enclosed sanctuaries, have costly chemical or wire fences. Expenses are quite often shifted onto the unsuspecting taxpayer or ratepayer without proper analysis of the value of the spend. In the absence of mainland New Zealand becoming pest-free, fenced sanctuaries will require centuries of commitment so that the gains will not be lost the minute interest wanes, funding dries up and the fence is breached. Any conservation project can also have its detractors, and I didn’t fancy dealing with sanctuary neighbours who might be unhelpful or hostile either. An island project was therefore top of my mind.

To state the obvious, islands far enough from the nearest pest-infested area already have a fence. It’s not impermeable, but we figured that provided a pest-free island’s tenure was impermeable, it would cost little to ensure that traplines, bait stations, tracking tunnels were monitored in perpetuity. The same thinking has many islands in State ownership at the forefront of conservation efforts as arks for threatened species, pending the mythical breakthrough on the mainland.

Having figured an island project might be the one for us, we knew there was a dearth of choice. Many worthwhile islands are already in public ownership, and many are in multiple undivided title based on traditional tenure but stymied from contributing economically or conservation-wise through the paralysis brought by having many owners. Most or all of the easily accessible, fee-simple private islands have become the playthings of the rich (local and foreign), with little or no conservation benefit being contemplated or implemented. The larger ones have usually been subdivided and therefore would be difficult to bring under effective management for conservation purposes.

I was aware of Puangiangi when Ross Webber put it on the market in 2004. It was still in play simply because Ross had kept hold of it for 47 years through waves of island-buying fever, and because the more intelligent well-heeled could see it was a nightmare to get to and build their mansion on. 2004 was not the right time for us though and it didn’t compete for dinnertime discussion on top of everything else in our lives. The government’s Nature Heritage Fund was interested and put up a proposal to buy it, which was ultimately rejected by the then Labour conservation minister. It therefore went the way of the others, in to the hands of a property-developer type who had no interest in conservation, largely  financed by Ross leaving money in (I can only hope without the benefit of professional advice).

AirNZ
Photo taken for 2004 sale finds it way into Air New Zealand’s in-flight magazine, in an article about Rangitoto near Auckland. Perhaps the backdrop of D’Urville rather than the Sky Tower might have assisted in getting it right.

Conservation got a second chance though when the interim owner fell over and Ross got the island back for resale. Ross just wanted the mortgagee-in-possession headache to go away, but still preferred the island to go to someone who would make good use of it. After there had been some shenanigans with another local property, he wanted to know we weren’t just a front for offshore buyers, and interestingly he did not think the Government would make the best possible custodian either. Peter knew Ross and gave us a good reference. Our 2012 tender was accepted and Ross was finally free of an island he had left 8 years previously at age 74.

This link http://www.cnbc.com/id/48300484 contains a CNBC video (scroll down a fair way) which evidently passes for news, and says much about the mind-set around islands that we did not want to see continue for Puangiangi. (The numbers in the video are laughably wrong by the way.) It took plenty of effort but the island is now safely held by our Charitable Trust. It must be used for public benefit (conservation) according to the law and to our Trust Deed. Although we take plenty of selfish pride in having got it this far, the asset is strictly alienated from us and is not our personal property. Our intention is that our Trust will become a perpetual one, and we have also been obtaining advice from DOC’s legal people about the best overlying structure to put on the island to further ensure protection. Interestingly they are not currently recommending any of the Wildlife Sanctuary options and the like available under the Wildlife Act, but lean more to the flexible Protected Private Land agreement offered under the Reserves Act. Extending the existing QEII covenant is also an option.

About the third question most people ask about the island (after “how do you get there?” and “can I come too?”) is “how big is it?”. According to a 1991 report by Ian Atkinson and Rowley Taylor, who compiled the predator status of all islands bigger than about 5 Ha, Puangiangi at “69” Ha squeaks into the 100 biggest at about Number 93. They measured areas by cutting out mapped outlines of the islands and weighing them. My estimate using a more modern method was 63 Ha. That is about 2.5 times the size of Matiu-Somes, a fair bit smaller than Mana but a similar length, and within coo-ee of many of the islands with the highest value to conservation.

Then what?

Well, apart from stating the obvious that we had managed to secure Peter’s services and thereby make the project viable, we wanted to get some other experts out for an ecological survey, and to write a management plan. My previous article talks about the botanical survey, you will find one about seabirds and future articles will cover land birds, lizards, and invertebrates. Having got some basic survey information, and with reference to the late Tony Whitaker’s 2002 plan for restoration of the adjacent Wakaterepapanui, from which we liberally stole (the plan, not the island), we got to preparing the plan.

CookStraitDistrict

The island is part of the Cook Strait Ecological District- think wind and salt. Islands include: Takapouwera/ Stephens; the Rangitotos- Wakaterepapanui, Puangiangi, Tinui; Nga Kiore/ Jags; Kuru Pongi/ Trios; Nukuwaiata and Te Kakaho/ Chetwodes; Titi; Mana; and Kapiti. Add the northern tip of Rangitoto Ki Te Tonga/ D’Urville, Capes Lambert and Jackson, the exposed headlands of Arapawa and the Port Underwood coast, and the coastline from Wellington to Kapiti. The mainland areas and D’Urville and Arapawa carry pest mammals, but all of the other islands have either always been pest-free or have had pests eradicated. Occasional incursions have been reported on many of them. Puangiangi is important to the ecological restoration of the other Rangitoto Islands, and vice versa given how close they are to one another. Puangiangi’s nearest other neighbours are Takapouwera and Kuru Pongi, which to a greater or lesser extent are seabird islands. I’ve previously discussed the place of seabirds as keystone species and to state the obvious we were always going to see Puangiangi as a seabird island. What level of intervention to achieve this is desirable?

Level 1: doing nothing apart from keeping pests away

kohekoheeaten

The island would be likely to re-vegetate rapidly, but forest development and health would be limited by grazing. Weed species such as pines and macrocarpas would spread out and might dominate except in those areas already with mature forest. New weeds might arrive and establish. The weka would probably prevent seabird establishment and they would limit growth of the reptile population. To state the obvious, we would have only the limited range of birds, lizards and invertebrates that were already there, plus one or two self-introductions. The outcome would be a modified Cook Strait ecosystem.

Level 2: Level 1 plus removing sheep, weka and weeds and keeping it that way

Sooty1aThis option would allow seabirds to establish, and the forest would over time regenerate to what it would have been, minus any lost taxa. The populations of the existing animals plus any that could get themselves there would increase as habitat improved. The outcome would be a fully functional seabird island typical of Cook Strait.

Level 3: Level 2 plus restoration and translocation

robinThe reintroduction of species not on the island but which should be, gives an ecosystem rather close to what it would have been before humans and pests came along. If threatened species were included in translocations, it would help their security by giving them an additional site.

Level 4: A refuge

IMG_0284_1xThe island could be made available to house acutely threatened species, possibly at some detriment to an ecological restoration intended to provide a typical assemblage of plants and animals.

Preferred Intervention

The island’s size, location, security of tenure and good likelihood of being able to stop it filling up with pests again, convinced us that the highest-cost option, Level 3, was too good an opportunity to miss. We were able to formulate our goal pretty easily and to state the obvious, we propose “to return Puangiangi to a state that most closely resembles a fully functioning, Cook Strait seabird-island ecosystem in pre-human times”.

An earlier article talked about our approach to restoration of the forests and shrublands, and to support this our plan includes how to reduce the risk of a fire, which would be the single biggest threat. Realistically we can’t fight a fire except perhaps around the house, but we have a total ban on open fires and smoking.

Also integral to the goal is having  a proper biosecurity plan and all visits involve bag and equipment checks to reduce the chance of assisting pests to arrive. Unfriendly signs discourage trespassers and mitigate the attendant risk of bringing pests ashore. The island’s title extends to the waterline and there is no foreshore reserve or Queen’s Chain, so landing is able to be prohibited.

As for species reintroductions, we have made lists of birds, lizards and invertebrates based on what is found or should be found on the other relatively unmodified islands in the area. Our thinking about seabirds is described in a separate article. Land bird species that were missing in 2012 and might have been expected to be there include tui, bellbird, brown creeper, tit, robin, kakariki, fernbird, kaka and saddleback, not all of which might be a good idea to reintroduce. Lizards initially identified as candidates included spotted skink, speckled skink, Duvaucel’s gecko, striped gecko, and Marborough green gecko. Tuatara and frogs might also be expected to have occurred there. Missing invertebrates could include Cook Strait giant weta and ngaio weevil.

I hope that doesn’t read like a shopping list to establish yet another zoo masquerading as an ecological restoration. The emphasis is on commoner species which would have been present on the island, not some hodge-podge of threatened species based on the “I want” attitude, to which DOC appears to acquiesce all too often.

It’s worth noting that our goal is also consistent with DOC’s objectives for the region, as expressed in their Nelson-Marlborough and Island management strategies. It also fits in with the Department’s aims for management of individual species.

Although we did not look seriously at Level 4, a refuge for acutely threatened species, the island would probably be able to support small numbers of, say, kiwi, takahe or orange-fronted parakeet. We figured however that there were better opportunities to provide a long-term secure site for such animals. For example, although several pairs of takahe would thrive on the pasture lands, we see the grass reverting to forest over the next few decades, thereby displacing takahe. We did see a role for Puangiangi as emergency accommodation though. We made DOC aware of this and indeed the recent discovery of mice on Maud/Te Hoiere meant the island hosted some refugees from there.

We think we can get rid of the weeds and do all of the species translocations in ten years. The other tasks, not requiring large one-off efforts but more steady background work like maintaining the predator-free state, attracting seabirds, catching weka, keeping up biosecurity and fire measures, engaging with the owners and administrators of the other islands in the group, maintaining the infrastructure on the island, reviewing the management plan and keeping records of progress, will carry on, to state the obvious.

Forests, Shrublands, Grass and Cliffs

When Peter, Sue and I visited Puangiangi to look at it before buying, we could see the expected forested areas and pasture from the boat, but the landing area was inauspicious. A few big pines, brush wattle, tree lucerne, kikuyu grass and a pohutukawa, weeds or out of their natural range, were near the track from the landing bay. On reaching the edge of the first forest remnant I saw it was eaten out underneath by sheep and contained, groan, what I thought were some olive trees.

Once I’d had a chance to think and observe properly, however, I realised they were adult fierce lancewood, Pseudopanax ferox, something I’d only seen as the distinct juvenile form in gardens. This rare plant was everywhere and the project started to look like not just a restoration but also one where special plants occurred and could be protected. Things continued to improve when we found the forest sheltering the house to be reasonably sound coastal broadleaf forest, with a canopy of kohekohe, hinau, titoki, kaikomako, nikau, P. ferox and another rarity, large-leaved milk tree, Streblus banksii.

IMG_2021_1
Juvenile Pseudopanax ferox, with fivefinger and Coprosma propinqua, D’Urville as a backdrop

That day we also had a quick look at the farmed area, where rank grass was being slowly invaded by tauhinu, with not a broadleaved seedling in sight, and at a manuka remnant on one of the high points. A circuit in the boat before heading back to French Pass revealed several forest areas, regenerating scrub, shrublands, swathes of wharariki/flax (Phormium cookianum), cliffs and screes.

One of our earliest priorities after taking over was to do a proper ecological and botanical survey. Geoff Walls, Barbara Mitcalfe and Chris Horne came out in October 2012 for a two-day survey which turned into five when we were caught by a storm. Geoff and his family own land on D’Urville and he is a very experienced ecologist, also having visited Puangiangi as early as 1981. Marlborough District Council part-funded his visit so he could do a Significant Natural Area assessment for them. Sue and I have been privileged to spend time on field trips with Wellington Botanical Society éminences grises Chris and Barbara. The three did the most comprehensive botanical survey yet on the island, putting up with the general topography, rain, having to crawl along ridgelines as the storm hit, and still having the energy to be witty and intelligent company back at the house. Barbara was undeterred despite being high up the waiting list for a knee replacement and Chris’ supply of filthy limericks was inexhaustible.

IMG_1563_1
Chris and Barbara (note ever-present hand lens), October 2012

The team compiled a list of some 138 indigenous vascular plants and made a vegetation map. The island’s ecosystems comprise:

  • Coastal broadleafed forest, 15%;
  • Regenerating coastal broadleafed forest, 10%;
  • Mixed coastal shrublands with wharariki, 20%;
  • Pasture with tauhinu, 27%;
  • Kanuka and Manuka shrublands, 2%;
  • Salt turfs, 1%;
  • Cliffs and scarps with scattered vegetation, 25%.

(This is my slight simplification of the information in Geoff’s report and I have also  tweaked the area percentages to make them add up to 100 once again.)

The Broadleafed Forest

This forest is typical of many in the Cook Strait Ecological District and Wellington residents familiar with Otari/Wilton’s Bush would feel at home with the mix of common trees given above for the forest around the house (Telecom Bush). The predominant tree is kohekohe. Soon after possum and rat control began at Otari, Sue and I began finding strange black fruits on the ground. I had never seen a fallen kohekohe fruit, as possums ate nearly all the flowers and rats got any fruits that did develop. The kohekohe are a real feature of Otari now pest numbers are way down. Puangiangi has never had possums and no longer has rats, and it is such a pleasure to see the kohekohe trunks in early winter, covered with white flowers, to be followed by copious fruits in summer. The multi-stemmed trees have great character, hanging on on the steep and sometimes mobile slopes, their canopy shorn off by salty gales.

KohekoheTrio

L-R: Kohekohe flowers, June; carpeting the ground; fruit, December

 

In the northeastern forest, which has stabilised screes, boulders and vertical slabs and must be near the slope limit to have vegetation cover, many of the kohekohe have stopped piles of rolling rocks on the uphill sides of their trunks. They have marched up to gain the ridge in a couple of places and hang on in the 150 km/h gales, making little oases of relative calm. They share the northeastern forest canopy mainly with akiraho (Olearia paniculata), a particularly indestructible giant tree daisy, and fivefinger (Pseudopanax arboreus), the only other Pseudopanax apart from P. ferox on the island, which is a little surprising given the species diversity elsewhere in the district. There are also some karaka, ngaio, Streblus, mahoe, tree broom (Carmichaelia odorata), wharangi, puka (Griselinia lucida) and kohuhu in the canopy. The puka are very large and terrestrial, and their grooved trunks/roots snaking up and down the rocks are a highlight. The kohuhu (Pittosporum tenuifolium) is another Cook Strait special, with its salt-resistant leaves being much more leathery than in the mainland form.

Under the canopy and in open spots, kiekie forms swathes which slow progress for those intrepid enough to explore the forest. The rockier areas have gardens of rengarenga lily, which of course also extend to the open cliffs. Lara Shepherd at Te Papa has been doing a DNA analysis of rengarenga from around the country, and a specimen from Puangiangi has the same provenance as others from the northern South Island area, likely deriving from early Maori plantings of material brought from the North. There are a few lianes, with Metrosideros perforata adding some colour to proceedings. The forest floor is populated with a typical array of ferns- Asplenium, Blechnum, Microsorum, Polystichum, Adiantum,and one of Sue’s favourites, Lastreopsis velutina. Also on some of the slabs is the little Peperomia urvilleana.

KohekoheCompo
Kohekohe forest without an understory save for the unpalatable Polystichum (photo courtesy Geoff Walls), and vigorous regeneration in the prolonged absence of sheep (photo courtesy Roy Grose)

The other main areas of mature forest are Telecom Bush and a large area at the south of the island. Both are on slightly gentler ground, and Telecom Bush in particular was more affected by sheep. Now the sheep have gone, there is slow but gratifying regeneration of the understory. These forests have all of the canopy trees of the northeastern forest and add hinau, nikau, tree ferns and a few tawa. Peter and I have had a fair amount of time letting gravity take us round the southern forest, looking for sooty burrows, and we were pleased to find the tiny group of adult tawa that eluded the botanists. A brief survey in 1996 by Nelson Botanical Society had however recorded a seedling tawa, so we had been hopeful of finding its parents. Summer 2016 brings several tawa seedlings to the forest with regular though light rain helping them hang on. One has even popped up in Telecom Bush and we think the kereru may also be bringing the seeds from Tinui where there is an extensive grove.

MPerf_Nikau
L: Nikau inflorescence coming out, last year’s fruit behind; R: Metrosideros perforata; both photos January.

Apart from the areas of mature forest, there is substantial regeneration afoot, especially between the southern  forest and the central pasture lands, and on the southwestern slopes of the island high point down to Boatshed Bay (part of the area covenanted with QEII National Trust by Ross Webber in 1999 and retired from grazing then). These areas are dominated by fivefinger, akiraho, ngaio, mahoe, kawakawa, kohuhu. P. ferox, Coprosma propinqua, C. robusta and the hybrid between the two coprosmas. C. propinqua, tree broom, mahoe, mingimingi and tauhinu play host to the mistletoe Ileostylus micranthus, which is quite uncommon on the mainland because of selective possum browsing among other insults. It has also colonised tree lucerne, introduced around the house and slowly spreading elsewhere. On the non-native, leguminous host the Ileostylus can reach 3 m across in a lush, dark green as opposed to the often more “natural” pale yellow-green on the native hosts. Most of the forest trees are beginning to make an appearance, with the first kohekohe having just shown up in the covenanted area. The regenerating forest is extraordinary in its diversity and productivity, the abundant fruiting of the fivefinger being of special note to us and I expect the birds. It has come back quite quickly as the accompanying photos from 1981 and 2012 show.

19812016South
Looking south to north, 1981 (above) and 2016 (below). Broadleaf forest regenerating at right. At far left, pasture finally retired in 2013 reverts to tauhinu. 1981 photo courtesy Geoff Walls.

Barbara and Chris are strongly of the view that this regeneration neither needs nor wants human assistance. Their philosophy is perhaps derived from the project at Hinewai, where nature is left to take its course no matter how long or short that might be, and they certainly don’t recommend the more extreme replanting interventions which Chris recently likened in a Letter To The Editor to little more than “gardening”. I share their view for the Puangiangi project, where unassisted regeneration is doing very nicely thank you. We might however temper this with a little bit of moving of kohekohe seedlings around the edges of Telecom Bush, which have been planted with shelter trees native and exotic and gardened in the past, and which might benefit from a bit of evening up of the species present.

The Stable Shrublands and Salt Turfs

IMG_2036_1

The northern end of Puangiangi and some of the other ridgelines are a delight. Here the winds are too extreme for the broadleaved forest to take over any time soon, and the land is covered with a waist-high biodiversity treasure trove.

CookStEndemicsComposite
Clockwise from top left: Cook Strait kowhai flower, August; kowhai in situ (photo courtesy Geoff Walls); Melicytus sp.

The Cook Strait endemics shine, with three little mahoe relatives to the fore, Melicytus aff. obovatus “Cook Strait”, M. aff. novaezelandiae “Maritime” and a hybrid between them (identifications courtesy of Peter de Lange from specimens provided by Barbara). Here we also find P. ferox, Coprosma propinqua, taupata, ngaio, prickly mingimingi, wharariki, and clumps of dark green which we were excited to find was Cook Strait kowhai. It not only grows in the tangle of the more mature shrublands, but dominates some of the cliffs of harder rock down to within 20 m of the sea. Last winter I took the kayak out in the late afternoon and I could look up and see the kowhai flowers glowing yellow on the cliffs. If I had to pick one botanical standout on the island it would be these shrublands with their thriving populations of rare Strait endemics.

At and around spot height 120 m in the middle of the island is an area of manuka. Outliers have colonised the surrounding pasture on the western side down to near sea level. This part of the island is of gentler contour, being merely steep rather than precipitous. It would once have held the broadleaved forest we see elsewhere today, perhaps supplemented by a few missing trees such as matai and miro which occur on some other islands in the area. The forest cover might have helped the relatively large catchment there to have held water nearly permanently instead of ephemerally as today. The number of young manuka popping up and the relative absence of competing broadleaf seedlings (which were eaten by the sheep) might mean that the area of manuka shrubland expands and dominates the central third of the island for many decades. We need only look across the channel to Tinui to see how effectively manuka can come back on retired pasture.

Tinuicomposite
Tinui from summit of Puangiangi, 1981 (above) and 2016 (below). Tinui was stocked and periodically fired until maybe 1960s, now clothed in manuka. Note succession from tauhinu to fivefinger and P. ferox on Puangiangi. 1981 photo courtesy Geoff Walls.

An area of kanuka dominates the 128 m summit of Mt Mistaken above the southern broadleaf forest and is spreading down the western slopes. Some of the kanuka at the very edge of the forest are large and old, and their copious litter makes great robin territory. The lower plants on the very exposed areas are festooned with the rare mistletoe Korthalsella salicornioides, its stems blending very well with the kanuka foliage. I was aware that it might be around, but still managed to walk past the main colony about eight times before Chris and Barbara spotted it on their first outing. It’s likely that kanuka will be the dominant species here for a very long time.

KanukaComposite
Kanuka spreads out, Mt Mistaken. Korthalsella salicorniodes at right.

Another rare plant found in the shrublands and open spots is wind grass, Anamanthele lessoniana. It was also obviously a favourite of Ross’, as he planted it around the house for low shelter and ornament, with its lovely showing of the wind through its blades and its seed-bearing tillers up to 2 m long. It’s fair to say that Puangiangi is also a national stronghold for Anamanthele.

IMG_0785_1
Salt turf assemblage. Photo courtesy Geoff Walls.

At the southwestern corner of the island is an area of salt turf relatively unmodified by sheep. If Ross Webber or earlier farmers had ever had cattle it might have been lost. Here in the spray zone is a big area of silver tussock, native iceplant, glasswort, Samolus repens, Selliera radicans, Senecio lautus, and the two native daphnes Pimelea prostrata and P. urvilleana. These plants also occur sporadically around the shore and on open ridges. A monocultural salt turf of the little buttercup Ranunculus acaulis is at Woolshed Bay, by an archaeological site containing argillite, human-transported stones, charcoal and small bones. This area is more degraded by heavier grazing.

Cliffs and Scarps

OLYMPUS DIGITAL CAMERA
The eastern screes and cliffs. Photo courtesy Geoff Walls

Most of Puangiangi slopes very steeply away into the sea. Although Ross told me he used to muster one of the very steep eastern faces on foot, we confine our interaction to views through binoculars or at the end of a rope drilling and poisoning some of the more easily accessible coniferous weeds.

The mobile scarps of scree and softer rock may once have held a forest of sorts, but at the moment they are limited to a few patches of grey scrub. From below, the largest scree looks devastated, the shoreline littered with boulders which appear recently arrived and a more or less constant stain of sand and mud in the sea. On a gentler bit, an island of forest hangs on- or has colonised, I don’t know which.

IMG_1429_1
Wharariki in the salt exposure zone

Where slope, soil or aspect allow, the steeplands in the spray zone have extensive fields of low vegetation, dominated by wharariki (Phormium cookianum), silver tussock and with patches of rengarenga lily and linen flax (Linum monogynum). The latter two add a splash of white during flowering in spring. The shrubland species described earlier also make inroads. There are a few areas of hard rock cliffs, sometimes hosting rengarenga and Cook Strait kowhai.

Pasture

P1010274_1
Claire Gaze sets off for the butcher’s, January 2013. Photo courtesy Peter Gaze

The central third of the island has gentler slopes and more shelter and it’s logical to see the influences of past farming lingering there the longest. When we took over we were nonplussed to find a flock of some 20 sheep, left to their own devices for some years. It was obvious from a restoration point of view that they had to go, but having established that they weren’t suffering through disease burdens, lack of water or sweltering in their enormous fleeces (which they were shedding), we decided to shoot them at the rate we could eat them. Sue’s family and our friend Jan from Toronto would be among the few to say they have had a Christmas dinner of the now-extinct Puangiangi sheep. Some of the older rams took a bit of cooking but I think it showed respect not to waste them. I also sent up a choicer lamb cut to Ross in Auckland.

By 2012 the pasture had become rank even with the sheep that were there. Tauhinu was all but the only coloniser, the sheep leaving it alone in favour of any broadleaf seedlings that came up. I bought from Television New Zealand some archival footage of a visit one of their journalists paid Ross as he was preparing to leave in 2004. Even at that stage he had the journalist out grubbing tauhinu.

WoolshedBaycomposite
Pasture at Woolshed Bay reverting to tauhinu from 2012 (above) to 2016 (below), in the face of extreme winds funneling up the bay. Note demise of macrocarpa at right.

By the time we arrived, the tauhinu was extensive but we could still walk anywhere in near enough a straight line. Now it is all but impenetrable in many places, manuka is spreading from the high point and broadleaf saplings are showing in the shelter of the tauhinu. We recently cleared some grass and tree lucerne at the edge of Telecom Bush and were surprised to find healthy kohekohe seedlings under the rank grass.

Weeds

At the start of this article I implied an initial negative impression of the island’s botany, formed by a weedy landing but since fixed by exploration and experts. Really though, we are pretty lucky having only the weeds we do. There is no gorse, Darwin’s barberry, hakea, climbing asparagus, old man’s beard, and so on. The ones we do have are isolated and controllable, and this influenced our decision to totally eradicate them apart from tree lucerne, pasture weeds (which will eventually die out as the forest grows) and probably kikuyu grass which is stabilising land at the two beaches for the time being.

P1010158_1
Macrocarpas colonise the eastern cliffs, 2012. If left they would eventually take out the Cook strait kowhai in the central background. Photo courtesy Peter Gaze.

A shelter belt of macrocarpa protected the country’s smallest woolshed (3 x 2 m) and its yards, dating we think from the King-Turners’ 1929-1957 tenure. The shelter belt itself was benign but seed was blowing on to the adjacent rock pavements and cliffs, and some sizeable trees had taken hold. Lest the island end up like coastal northern California, we engaged Marlborough Sounds Restoration Trust to spray the macrocarpas from the air with metsulfuron methyl, as they have been doing successfully with pines in the Sounds for some time now. We drilled and poisoned the accessible trees, one of which got its own back by blowing over and flattening the woolshed. Some of the trees are not dead yet after two visits from the helicopter and there are plenty of seedlings coming up, but we will persist. The house area held several large pines, presumably for shelter and firewood, and they have also been poisoned. Many have blown over now and some took out the access track when they did so. We have cut a hundred or so saplings from the covenant area, where the seeds appear to blow and take hold, and we are seeing only a very few now.

A single pohutukawa, presumably an ornamental planting, and an isolated pocket of European broom have also been dealt with, apparently without any ongoing seedling germination. An infestation of brush wattle around the house was cut down. The main area of wattle has now been taken over by regenerating shrubs and it is too shady there for any wattle seedlings. Further down-slope, the long-lived seeds mean regular attention is required to pull out seedlings, a thousand at a time if this month is anything to go by.

Outlook

All said and done, this is a botanical restoration that is proceeding very quickly with minimal effort from people, and it is reasonable to think that Puangiangi will be weed-free, and have at least developing forest over the former pasture lands, in my lifetime. The broadleaf forest will have a resilient structure with a diverse understory, and the island will become more widely known as a national stronghold for its astonishing range of rare endemics.