The future of our forests
Native forest once covered most of Aotearoa in a great green swathe, heaving with biodiversity. Two-thirds fell to fire, axe and bulldozer during a botanical Blitzkrieg the like of which the world has never seen. Today’s forest remnants are confined largely to areas of conservation land, but legislation can’t protect against pathogens, pests and invasive weeds that do not respect park boundaries. What does the future hold for our forests?
It’s late at night and a cold rain is falling when I reach Pureora Forest Park, a ragged patchwork of forest remnants that lies between Lake Taupo and the King Country. The carpark—a circle of gravel flanked by thick bush—is deserted. I brew a coffee, then roll up my sleeping bag inside a slab of foam, tie the bundle with rope and walk intothe forest. There is a steady, heavy dripping from trees that are taller than my torch beam can shine. Pureora is said to be one of the finest examples of podocarp rainforest in the world; about the only part of that description I can fully appreciate at the moment is rain.
Out of the darkness looms a wooden tower, four storeys high. It’s solidly built, the work of the local Lions Club; a philanthropic gesture to help people appreciate this place. I climb four steep flights of steps to the top, and haul up my gear. There is just enough floor space to unroll my bedding, and the roof extends out far enough to keep things dry. I wriggle into my bag and listen to the calls of night birds and the whirring of insects that fly around my head. I flick my torch back on. I’m being strafed by huhu beetles, or some of their relatives. Their wings sound like the propellers of model aeroplanes, and I feel a tiny breeze on my face as they pass. It is an enchanting way to be lulled to sleep.
Nature’s wake-up call next morning is more strident. Flocks of kaka shred the dawn with their shrieks, and the heavy whopwhop-whop wingbeats of kereru whistle through the canopy. Cackling parakeets add their calls to the mix. From the tower, I look down on the perfect green umbrellas of tree ferns and up into the crown of a neighbouring rimu, its branches laden with perching plants. Broadleaves slick with rain glisten an almost iridescent green.
This is historic—I’m tempted to say hallowed—ground. In 1978, Pureora was on the chopping block. The Forest Service intended to finish what had begun decades earlier: the logging of all the merchantable timber here—matai, rimu, totara, kahikatea, the pick of this country’s lowland podocarp trees. This despite the fact that, a year earlier, a 341,160-signature petition had been presented to Parliament, demanding an end to native-forest logging and legal recognition of native forests.
Stephen King, a quietly spoken young Aucklander with long hair and a penchant for going barefoot, decided the situation demanded something more emphatic than tabling a petition. He and some friends from the Native Forest Action Council drove to Pureora, obtained a camping permit, and set up camp…but not on the ground. Using a few ropes but relying mostly on vines, they climbed, Tarzan style, into the canopy of six totara trees and declared that Pureora must be spared.
It was a watershed moment—an enough-is-enough, this-madness-must-cease moment—and it led not only to the protection of Pureora, but also to the preservation of another outstanding podocarp remnant, at Whirinaki, on the edge of Te Urewera National Park, and eventually, in 2002, to the end of logging in state-owned native forests throughout the country.
Thirty-six years on, King is still climbing trees. These days, not totara for protest action but kauri for seed collection. King is a co-founder of the Waipoua Forest Trust, a partnership between local iwi Te Roroa and the Native Forests Restoration Trust that seeks to protect the forest and restore its surrounding catchments.
From his home, which he shares much of the time with volunteers, King looks across regenerating farmland where kauri and other natives are lifting their heads above a nurse crop of manuka. On his patio are rows of plastic containers with young kauri seedlings grown from seeds he collected from Tane Mahuta, New Zealand’s most famous tree. In a nearby nursery King has 3000 strapping young kauri, ready for planting out.
Part of the trust’s land is called the Professor W. R. McGregor Reserve, honouring the University of Auckland zoologist who devoted 30 years of his life to saving Waipoua from the axe and saw. The destruction of Waipoua, Roy McGregor wrote in 1948, would be “an everlasting and ignoble monument to the cupidity, the stupidity and the deadly apathy of this generation”. McGregor’s campaign prevailed, and in 1952, Waipoua was declared the country’s first forest sanctuary. Its immense kauri draw thousands to the west coast of the Far North each year to experience what McGregor poetically called “the spiritual and aesthetic lumber” of nature’s beauty—a dividend far greater than any cubic quantity of timber.
King, then, walks in the footsteps of a giant—and he still walks barefoot. He’s also as ardent an eco-warrior as he was in the 1970s and ’80s, though the battle lines have shifted. Then, the focus of protest was a government policy that—as in McGregor’s day—pitted forestry jobs against forests, and came down in favour of jobs. Now, the main threat to native forests comes not from within but without: an exotic army of introduced weeds, pests and pathogens.
“Green invaders,” King calls the weed brigade, and he wages war on them daily. He cites wild ginger and pampas, both of which require concerted, long-term efforts to eradicate. But other problem plants aren’t names most people would recognise. One of the worst offenders is the Australian bangalow palm.
“It’s a real shocker,” he says. “Once the pigeons notice them, next thing the seeds are in the middle of the forest. How are you going to find them? Something that creeps along the margins, then bulks up, like ginger, is bad, but not as bad as something that’s taken into the centre that you can’t find any more.”
New Zealand’s exotic flora has followed the 10 per cent rule, King says: 10 per cent of the roughly 25,000 plants that have been introduced to this country have become naturalised (hopped over the garden fence to establish themselves in the wild), and 10 per cent of those have gone invasive. There are now more introduced plant species living wild in New Zealand than there are natives, and it is estimated that eight new species naturalise each year.
Two of the garden escapees are among the botanical insurgents King faces at Waipoua. “Along the rivers our worst weed is African club moss, a popular pot plant in the ’60s,” he says. “It spreads by spores, so once it’s in a catchment it hitches a ride down the waterways. Another insidious weed is South African iris, Aristea. It came through forestry—first by graders, then logging. Now we’ve got 3000 hectares of it, and the seeds last for at least 10 years in the ground.”
I cringe when I hear about the iris. I’m trying to contain it in my own garden. It’s like playing Whac-A-Mole—knock it out in one place and it pops up somewhere else.
Sounding a more positive note, King adds that there is a lot the public can do about the weed problem. “The thing about weeds is that anyone can participate in getting rid of them. But there needs to be education. When conservationists talk about saving rare native birds, the public gets that. They can see it—bird numbers dwindling through introduced predators, their habitat degrading through forest browsers. With the green invasion it’s often harder to see. We need a co-ordinated effort to deal with it, because if you tackle it piecemeal it will beat you.”
The alternative doesn’t bear thinking about. “We’ll lose our indigenous uniqueness,” says King.
“Each country needs to guard its natural identity. We have to do so more than most because our flora and fauna are more vulnerable than most.
What we don’t want is a future in which we take our grandkids through the forest and have to say, ‘Somewhere over there, beyond those Australian tree ferns, is a ponga, and hiding behind those bangalow palms is a nikau.’”
King wants to take me to a lookout point to get a vista over the forest, but the rain has come, spreading across the hills like a cloak and blotting out the view. As I leave, I thank him for Pureora, for snatching the chiefly totara—the rakau rangatira—from the teeth of the chainsaws. King remarks that we have fewer tall totara standing today than we have MPs, and there are no reserves specifically set aside for totara. “Yet this is our national tree for eulogy,” he says. Kua hinga te totara. A totara has fallen.
He shakes his head. “It’s incredible what we have lost.”
And may still lose. As menacing as the guerrilla army of introduced weeds is—strangling, shading, displacing native species—an even more pernicious force is massing on our borders: plant pathogens. One of the most troubling is already making its presence felt in Waipoua and elsewhere: a micro-organism called PTA, Phytophthora taxon Agathis, where Agathis refers to the genus of which kauri is one species. PTA is the organism responsible for kauri dieback, a disease with the potential to topple even the most ancient kauri—trees whose age is measured in centuries.
Phytophthora means “plant destroyer”, and, true to their etymology, these organisms are a deadly force. One species caused the potato blight that led to the Great Irish Famine. Another is responsible for a disease so swift and fatal it is called Sudden Oak Death. A third is currently decimating the jarrah forests of Western Australia. There may be as many as 500 species worldwide, all of them plant pathogens. One microbiologist has described Phytophthoras as “biological bulldozers”.
I meet up with this tree leveller in the Waitakere Ranges, on the western ramparts of Auckland, one of the areas of kauri forest worst affected by the disease. With arborist Fredrik Hjelm and Auckland Council biosecurity adviser Nick Waipara, I explore an area bristling with 100-yearold rickers—spring chickens in kauri terms.
It’s immediately obvious that something is wrong. Many trees have yellowing leaves and a wilting canopy. Dead branches litter the forest floor. Resin bleeds from lesions around the bases of several trunks, solidifying in the air to a ghostly white crust.
Resin is the kauri’s chief defence against biological or physical attack. The trees are bleeding because they are fighting. But many are losing, and some have lost. Their gaunt dead trunks attest to the virulence of the pathogen.
“In the lab, PTA can kill a seedling in two to 10 weeks,” says Waipara. “In the wild, we don’t know how long it takes for a kauri to succumb, because there are many environmental factors that come into play. But we know that no stage of the kauri life cycle is immune. The disease takes out young saplings, teenage rickers and taonga old trees.”
PTA attacks the fine feeding roots of kauri, choking off the tree’s essential nutrient-and water-transfer system. Like an asthma sufferer gasping for breath, the canopy can’t get the nutrition it needs. What makes the pathogen especially dangerous is its ability to spread through the soil of its own accord. [See sidebar, Kauri’s last stand] PTA spores can swim several metres through soil water in a year, but the disease has moved exponentially faster than that because of soil transfer by humans and animals. “Anything moving through an infected root zone—a feral pig, a cow, a tramper, a mountain biker, a forestry worker, a cannabis grower—can spread the disease,” says Waipara.
Of the kauri dieback zones that have been identified, 68 per cent are within 50 metres of a walking track—a clear signal that trampers are implicated in inadvertent soil movement. To limit spore transmission, some high-risk tracks in the Waitakere Ranges have been closed, and hygiene stations for boot-scrubbing (and in some places bike tyre-washing) have been set up at track entrances—including the one we used to reach this site, a couple of kilometres inland from Piha.
Hjelm organises ropes and harnesses and we climb two kauri rickers to get a canopy-eye view. It is both exhilarating and poignant to be aloft in these princes of the forest—like being up the gently swaying mast of a yacht. I reach out to touch a female kauri cone, a spiky green golf ball borne at the tip of a branch, and lean close to the trunk to get a whiff of fragrant conifer sap where a branch has dropped, leaving a clean scar sealed with sticky gum. I think of the gum climbers who worked in these forests more than a century ago. No fancy climbing gear for them. They scaled mature kauri with just a pair of sharp hammers and spikes in the toes of their boots, risking their lives for the cache of gum that might lie in the crown.
From my perch 20 metres up, the forest looks good. The canopies of rewarewa, rata, tanekaha and rimu are vibrant. Their health only accentuates the sorrowful state of the kauri. Three out of every four rickers look sere and pinched, showing symptoms of dieback.
One of the complications with this disease is that not all sick trees are necessarily infected with PTA. Trees can lose condition though various forms of environmental stress. It has long been known that kauri are susceptible to disturbance of their root systems. Drive through Waipoua and you will see several dead roadside kauri—grey ghosts, devoid of bark, their leafless branches as stark as deer antlers. Disruption of their fine feeder roots and associated mycorrhizal fungi through road construction is thought to be the cause of death.
“Kauri trees have probably been under stress for a long time,” says Waipara. “The fact is, there are no undisturbed kauri forests left, and the total area of kauri alive today is less than three per cent of its original extent. Is it surprising that a soil-borne pathogen operating in a disturbed soil system should be proving so deadly?”
Averting a tragedy for kauri means learning not just about PTA but about the ecological system in which it operates—and its cultural context. “That’s been an important lesson,” says Waipara, “bringing matauranga Maori into the biosecurity space. The Maori worldview and the ecological world-view turn out to be amazingly close. They’re both about the big picture. They just say it in different language.”
Hori Parata, a member of the kauri dieback tangata whenua reference group, has a saying: Ko te kauri he whakaruruhau mo te iwi katoa, kia toitu he whenua, kia toitu he kauri. Kauri is a shelter for all people, so that the land is sustained and the kauri stands proud. This view aligns with the ecological understanding of kauri as a keystone species in the forest. Kauri are not just culturally iconic, they are ecologically pivotal, affecting their surroundings in profound ways and controlling to a large extent what lives under and around them.
And in them. Kauri, like many native trees, support large epiphytic communities in their branches. Tane Mahuta is said to have 47 plant species living in its crown. Te Matua Ngahere, another Waipoua Forest kauri giant, had a 400-year-old rata growing in its canopy until a storm in 2007 knocked it out, taking several of Te Matua’s branches down with it. A cross-section of one of those branches had 1700 annual growth rings, which suggests that the tree itself may be several thousand years old. Stephen King told me he had seen tawa, rimu and totara growing together in a kauri canopy—a podocarp forest living in a conifer crown.
The ecology of these canopy communities—treetop islands of biodiversity—is almost unknown. In 2008, for her PhD dissertation at Lincoln University, Kathrin Affeld made the first comprehensive study of plants and invertebrates living in the New Zealand forest canopy. She climbed into the crowns of 40 northern rata on the South Island West Coast and found 170 plant species and almost 450 invertebrate species—“an astonishingly diverse and complex canopy flora and fauna”, she wrote in her thesis.
When I met her in Lincoln, I asked what had been her most memorable experience during her time in the treetops. “I remember sitting in a tree at Punakaiki and hearing a loud buzzing overhead, and I realised it was coming from hundreds of native bees, wasps and flies,” she said. “There was a sense of being decoupled from life on the ground and exploring uncharted territory.
The plant and animal associations in the canopy are incredibly varied and quite different from those on the ground.”
She found earthworms that had wriggled up the tree trunks to reach the rich tilth that develops in the crowns. She found colonies of native ants. Ants, in fact, were the third commonest invertebrate in the canopy, behind mites and springtails. Several of the invertebrate species Affeld recorded were rare or absent on the ground or new to science, including a scale insect that is a new genus.
Affeld speculates that some native species may find sanctuary from predators or competitors in the canopy. If so, that would come as no surprise to Maori, for whom kauri is the tino herenga—the mooring point—for all things.
“There’s no such thing as a tree on its own,” Hori Parata told me when I visited him in Whangarei. “It’s a whanau. When the whanau is intact, everything is healthy and strong. When it starts to break up, that’s when you get things like this dieback disease.”
For Parata, the fragmentation of the forest has a painful parallel in the fragmentation of his people. “Papatuanuku is like us, man. She’s sore. She’s tired. She’s hoha. She’s losing her resistance. What I’m saying to them on the programme is that we need to listen to her. If we don’t find a balance between matauranga Maori and Western science, we’re wasting our damned time.”
In the beginning was the forest, and the forest was the offspring of Tane, and the forest was Tane. Another version of New Zealand’s forest origins comes from palaeoecologists who have painstakingly assembled a picture of early New Zealand from fossil pollen and other sources. That view depicts a pre-human landscape 85 per cent covered in forest, with the remaining 15 per cent in alpine meadow, tussock grassland and other vegetation types.
However you express it, Aotearoa was a land of forests, the Amazon of the South Pacific. Maori burnt off much of the forest on the dry eastern sides of both islands, but the main clearance occurred when Pakeha arrived.
Within 100 years of European settlement, Amazon had turned into England, forest into farm, scowling bush into smiling paddock.
Environmental historians say that the transformation of the New Zealand landscape was the fastest in human history. It was nothing short of a revolution. “What in Europe took twenty centuries, and in North America four, has been accomplished in New Zealand in a single century—little more than one full lifetime,” wrote acclaimed New Zealand geographer Kenneth Cumberland.
For the most part, colonists considered the country’s ecological makeover an outstanding achievement and a triumph of progress. “Improvement” was their watchword, and they applied their imperial ideology to people as well as land. Just as indigenous nature needed to be subdued, tamed and civilised with superior introduced species, so must the indigenous people be liberated from their barbarous ways. Hadn’t Darwin said that the weak must give way to the strong? The bitter legacies of that reforming zeal are with us still.
I travelled through what was called the Seventy Mile Bush to get a sense of the scale of loss, to confront an absence. This forest, like the huia it once harboured, now resides only in memory. If you look hard enough, you can find scraps of regenerating native vegetation in gullies too inconvenient to keep in pasture—scattered islands in an ocean of pasture—but a single forest extending from Wairarapa to Hawke’s Bay is unimaginable.
Missionary explorer William Colenso called Seventy Mile Bush the most primeval forest he had seen. The trees were so tall and thick that no sunlight ever penetrated to the earth, wrote George Conrad Petersen, the son of Scandinavian immigrants recruited for their forestry experience. “On the creek flats were groves of rimu so thick in places that the tall, clean, brown boles presented a solid wall of timber,” he wrote in his memoir, Forest Homes.
Almost every stick of it came down. Levelling the forest was a family affair. A boy of 10 was considered fit to wield a slasher, and at 12 he would graduate to a heavy axe, wrote Petersen. “Mother would have her light axe with which to attack the underscrub.” At the end of the process the felling and the burning—lay “a desolation of blackened earth… from which rose the stark bare stems of the giants that had been spared the axe to perish in the flames”.
What drove the wholesale destruction of the country’s lowland forests? Eric Pawson, professor of geography at the University of Canterbury, says commercial opportunity was at the heart of successive waves of deforestation.
“When you look at how the bush frontier retreats, it’s timed with resource frontier booms which are themselves related to the export markets that were being created for particular products at particular times,” he tells me. As different markets opened, different areas were cleared. In Northland, the peak kauri-milling years—1870 to 1910 coincided with demand for house-building timber on both sides of the Tasman. The catalyst for levelling lowland podocarp in Taranaki and Waikato was the advent of refrigeration for dairy products in the 1880s and ’90s. After World War I, the burgeoning export trade in frozen meat led to widespread forest conversion.
In the case of kahikatea, the catalyst for removal was not the value of the timber but that of the wetlands where the trees grew. “The 1913 Royal Commission on Forestry stated bluntly that kahikatea forest should be replaced with grass forthwith, because that was where the income-generating potential lay,” says Pawson.
New Zealand’s manifest destiny was to be Britain’s farm, and forested landscapes didn’t fit with that vision. During an 1894 parliamentary debate on “land improvement”, one MP advocated that every indigenous tree should be burned to the ground—with the exception of totara and rata, which could be turned into fenceposts and building materials. Another member added his opinion that native bush, though scenic, was useless. Even the Premier, Richard Seddon, averred that “every tree felled meant the improvement of the public estate”. In settler eyes, idle lands were the devil’s helper.
Yet it would be a mistake to think that the voice of conservation was silent during these years. [See sidebar, Who spoke for the trees?] As early as the 1850s, a few settlers were deploring the profligate cutting of native forest, especially in the eastern South Island, where stands of forest were rare. In 1868, Thomas Potts, a Banks Peninsula run-holder, urged Parliament to take up the cause of forest conservation and put an end to the “barbarous improvidence” of ransacking the forests.
Six years later, Premier Julius Vogel took up the conservation cause, championing an act that would allow for the creation of state forests and the appointment of a forest conservator. He argued for conservation on utilitarian grounds—the forests’ role in preventing soil erosion and land desiccation, in providing a sustainable supply of timber, in stabilising watersheds and regulating climate—but he also spoke of forests’ intrinsic value. They helped shape the “beauty, healthfulness and pleasure-bestowing qualities” of the nation, Vogel told Parliament.
It would be another 25 years, however, before the country had legislation enabling land to be set aside for its “non-productive” qualities. Tourism was one of the motivations behind the passage of the Scenery Preservation Act of 1903. Its boosters believed there was a golden egg of revenue to be had, and New Zealand’s scenery was the goose that would lay it. Hardline pastoralists grudgingly conceded that people seemed to like our natural landscapes, but argued that nothing must stand in the way of settlement.
In debating these measures, parliamentarians kept a clear distinction between production land and land that could be spared for scenic purposes—a utilitarian split that still dominates government policy today.
“The separation of protected areas from production land has been a repeating pattern in settler colonies,” Pawson tells me. “It’s quite different from what you get in Europe, where national parks are often working landscapes. In the colonies, the conservation estate is the bit that’s left over, that isn’t considered much good for production purposes.”
That view is changing, he says, and has done since the 1970s, when attitudes to conservation shifted from preserving the residual to protecting the representative. In 1981, Okarito’s lowland forest was added to Westland National Park, and a few years later, Paparoa and Kahurangi National Parks were created. “This was partly a political response to voters in metropolitan constituencies who were becoming aware of the loss of lowland forests,” says Pawson. “Politicians recognised that these people could go any which way in an election.
“There was another factor, too. Forestry companies were losing interest in milling areas that were becoming highly politicised and not cost effective. In achieving forest protection, politics and economics were just as important as aesthetic concerns or intrinsic values.”
Underlying all these developments, says Pawson, are issues of national identity. “Over the past 30–40 years, people have been thinking about what makes New Zealand and New Zealanders distinctive.
What does it mean to create a home on a group of islands in the South Pacific? What sorts of landscapes do we want to pass on to our successors?
The rapidity with which people have become aware of and outspoken about environmental consequences of dairy farming—doesn’t that say something about how, collectively, we have come to value the place in which we live?
“I don’t personally think that means recreating a lot of Edenic native landscapes—I also don’t think that’s possible. It may mean a deeper appreciation of the landscapes that we’ve ended up with, which are often hybrids of native and introduced species. Yet these new mixed landscapes are something many people are comfortable with and identify with.”
Is this what our forest lands will look like in the future—ecological amalgams of introduced and native species? Should we even try to maintain a distinction between indigenous and exotic forest?
I put these questions to Matt McGlone, a palaeoecologist with Landcare Research in Lincoln and part of a team that focuses on ecosystems and global change. His speciality is reconstructing palaeo-vegetation patterns from fossil pollen grains. As someone well acquainted with the evolving composition of New Zealand’s forests since they started forming 2.5 million years ago, he brings a useful perspective to the issue of ecological change.
In 2005, McGlone helped the Department of Conservation develop a framework to assess the integrity of ecosystems on conservation land. With biodiversity in worrying decline, the department needed a way to rank and prioritise sites for management action such as predator trapping and possum control. The framework centres on the idea of ‘ecological integrity’. An ecosystem has integrity, it suggests, when all the indigenous plants and animals typical of a region are present, and their ecological relationships are functioning as they should. Also, indigenous species should dominate over introduced ones.
While these indicators are relevant for conservation land where the mandate is preserving indigenous flora and fauna, they don’t apply to all land, McGlone tells me. “I think we also need an ‘agro-integrity’ idea, because there are plenty of introduced things that we have come to appreciate in the landscape. I like going down to Central Otago and seeing the autumn colours of the trees. I like seeing introduced birds like goldfinches. These are legitimate elements in the biota. To damn that whole landscape as weed-infested and horrible is not consistent with how most New Zealanders regard and treat their environment.”
But what about the “green invaders”, I ask? What about the wilding pines that people are battling to contain around Queenstown and Craigieburn and in the Mackenzie Country and the Marlborough Sounds?
McGlone is adamant that we’re going to have to get used to our forests sharing their space with exotic species. “From a purist point of view, yes, they’re damaged, but you’ve still got ecosystems functioning roughly as they should, still got native species in them, still got representation, although perhaps not dominance. What will it mean if the Mackenzie Basin has a lot of pine forest in it? What will that mean for the native remnants that are left—the little patches of wetland and scrub? What’s at risk here?
“People love the tussock grasslands. I do, too. But they’re recent, a human construction [the result of fires set by Maori]. New Zealanders are particularly bad at this sort of ecological amnesia. They tend to think of their childhood recollection—the pohutukawa at the bach—as what is normative and what should be there in perpetuity.
“We need a more generous view of what such landscapes might be, because we’re not going to get them back to what they were. Let’s develop a concept of what a healthy landscape might be that doesn’t necessarily require indigenous dominance.”
But what about the stewardship obligations we as occupants of this unique country have towards its endemic biodiversity—the life forms that have arisen here and nowhere else? Along the corridor from McGlone, I put this question to one of his colleagues, ecologist Sarah Richardson. I had spent the previous day with Richardson and two other Landcare ecologists in Craigieburn Forest Park, looking at blended ecosystems of exotic conifer and native mountain beech.
“Historically, we’ve had this abrupt divide: production vs protection,” says Richardson. “On this land your job is not to be a kaitiaki of indigenous biota but to grow the economy. On this bit it’s permissible to focus on indigenous biodiversity. But that binary model hasn’t worked and can’t work, partly because there will be ongoing invasions, since many of our rarest plants are found in skeletal environments on the edges of forests, where conservation land meets production land.
“It’s easy to have black-and-white views on landscape: one or the other, native or exotic. It’s harder to define what might be an agreeable landscape, fit for purpose, delivering ecosystem services. They’re questions of balance and compromise.”
And compromise isn’t necessarily negative. Exotic plants can sometimes benefit native species. At Craigieburn, Landcare ecologist Rob Allen tells me that lodgepole pines—widely considered a scourge—can be an ecological asset in some circumstances. “It seems that in the eastern South Island, pines have the ability to break down organic material in the soil, making phosphorus available,” he says. “In our phosphorus-limited soils, that increases soil fertility.”
Pines and Douglas fir also provide a shading benefit for beech seedlings, protecting them from moisture loss. “Survivorship of beech has been shown to be much better under pine than in the open,” says Allen.
At Craigieburn, there is very little invasion of undisturbed mountain beech forest by Douglas fir, but it’s a different story around Queenstown, where the schist soils are higher in phosphorus and other nutrients. There, Douglas fir can establish in beech canopy gaps and even under intact beech canopy. The same is true of Hanmer Springs.
“So these invasion issues are context dependent,” says Allen, “and there is no one-size-fits-all solution.”
We’re standing on a ridge looking at a bristling horde of young lodgepole pines that have taken over a tussock grassland nearby. Parts of the stand have been slashed, other parts burned, other parts sprayed, but the green army appears to be marching unimpeded.
“A lot of passionate people want to kill ,” conifers says Landcare ecologist Duane Peltzer, who studies recombinant ecosystems, with their exotic/native blends. “But at what point do you walk away from an incursion like this? I think many people are realising they need to do something different, but no one is willing to say a place like this should be written off as a lost cause.” Spraying lodge-pole pines from a helicopter costs about $1000 a hectare and typically gives a three-to four-year window before the pines reinvade, he says. “You only need one or two missed trees, or seed to arrive from a nearby untreated block, and you’re back to square one. Pines spread incredibly fast.”
More than a million hectares of land is infested by wildling conifers. Can they be contained? Can we get rid of them? “The jury’s out on those questions,” says Peltzer.
On a fresh autumn morning, I turn from the conundrum of forests of the future to the contemplation of a forest from the past. With Landcare botanist Colin Meurk, I visit the last remnant of the prehuman native forest of the Canterbury Plains. It’s in an unlikely place—not some out-of-the-way rural outpost, but in central Christchurch, less than three kilometres from Cathedral Square. One minute you’re in heavy traffic on one of the city’s feeder routes; the next you’re watching bellbirds and rock pigeons flit through 25-metre-tall kahikatea canopy. The double gates of a predator-proof fence add to the sense of passing through a portal into ancient time.
Canterbury’s lowland forests were decimated by floods and fires lit during the early period of human settlement. The fragment now known as Riccarton Bush or Deans Bush was named Putaringamotu, the severed ear—a name suggestive of regret that so much of the great forest was consumed. That the Riccarton remnant, the size of two rugby fields, has persisted until today is incredible. Meurk calls it a “miracle forest”, and attributes its survival to the farsightedness of three Scottish settlers, William and John Deans and John’s wife, Jane. The Deans brothers settled the land in 1843. Both men died relatively young, and it fell to Jane Deans to fulfil her husband’s deathbed wish that the bush remnant be preserved. In 1914, it was gifted to the people of Canterbury by the Deans family as a permanent reserve.
Walking through this handkerchief of forest must be like holding the last huia. It is that unique, that special. Ecologically, it represents the southernmost limit of hinau, titoki and native passion vine. Twenty-seven of the country’s 39 families of butterfly and moth occur here. Culturally, it is a connection with what came before. A severed ear, perhaps, but still capable of listening to the echo of our origins.
We need that connection as never before. For decades, Meurk has been saying that most people’s experience of nature is in an urban setting. Large numbers of city dwellers—particularly those who are less well off, disabled, elderly or very young—rarely travel beyond the city fringes, he says. As more and more of the population live in cities, this lack of urban connection with nature will only increase.
For 15 years, up until the Christchurch earthquakes, he conducted “Meurky Walks”—guided meanders around the city that celebrated the natural environment. He was trying to counter what nature writer Robert Pyle has called “the extinction of experience”, the dwindling personal contact with nature that is, for many people, an inevitable consequence of urban living.
Yet there is no need for such disconnection and estrangement, says Meurk. “Christchurch has always understated its natural features, preferring to highlight trams, cathedrals and punting down the Avon. But the city has braided riverbeds, freshwater wetlands, dry plains ecosystems, coastal environments, a volcanic crater rim and other landforms and habitats. There are as many native plants growing in Christchurch as there are in our national parks. The city is the bellbird capital of the country. Why don’t we celebrate these things?”
Meurk believes that appreciation of native flora and fauna is essential for a sense of national identity and of what it means to be living in Aotearoa. “What’s more important to nationhood than the history of our landforms, our Gondwanan heritage and our indigenous people?” he asks. “There’s an enormous denial of that history. Our national and local government leaders seem to have only one thing on their mind: economic prosperity. They ignore deeper, richer, multidimensional values.
“Telling the story of our natural history should be up there with the All Blacks, the ANZACs and the Treaty of Waitangi.”
One of the practices that irks him is the city council’s reliance on exotic species for plantings in public spaces. He calls it the “green fluff” syndrome.
“It seems to be permissible to use tussocks and hebes around the edges, but the big landscape features—the noble park trees—are always exotics. Why aren’t we planting the podocarps of Canterbury—totara, matai, kahikatea? Are these not noble trees?”
The point is underscored in Deans Bush itself. On the lawn outside Riccarton House, the Deans’ stately homestead, an oak tree has a plaque identifying it as a “notable tree”, with the date of planting, 1849. No such plaques mark the kahikatea, kowhai or titoki in the reserve, the oldest of which were 300 years old when that oak was an acorn.
A different scale of values applies at a site on Banks Peninsula, 50 kilometres from Deans Bush as the kereru flies but a winding, spectacular 100 kilometres by road. Here another miracle forest is growing on the steep coastal hillsides beyond Akaroa. This is Hinewai Reserve, owned by the Maurice White Native Forest Trust and managed by botanist Hugh Wilson.
Hinewai began in 1987 when the trust bought an unproductive 109-hectare farm on marginal hill-country land. From the outset, the strategy was to use gorse, which ranged in rampant yellow profusion on the peninsula, as a nurse canopy under which natives could establish. In theory, the natives would over-top the gorse, shade it out and eventually eliminate it.
It was a bold approach, one which initially earned Hinewai the ire of some farmers on the peninsula. Wilson recalls those early days. “When we started, we put an ad in the Akaroa Mail saying we’d set aside this reserve, what we were hoping to do with the gorse, and that our dream was to see the restoration of a whole catchment, from summit to sea. Two weeks later, the newspaper printed a letter from a neighbouring farmer saying it was a lunatic idea, and that in the time it would take for natives to come through the gorse you could have had five rotations of Pinus radiata and put something back into the local economy. ‘As for setting aside a whole catchment,’ the letter went on, ‘heaven help us from fools and dreamers!’” Wilson hoots with laughter at the memory. “Today there isn’t a single farmer who isn’t totally for what we’re doing.”
Wilson explains that using the gorse as a nursery was a pragmatic decision based on the utter tenacity of gorse as a weed. “Everything people did about gorse only encouraged it. On marginal hill country like this, trying to control it by spraying only set you back to a point where gorse was the most competitive plant in the paddock.”
He suggests a walk to a lookout point along one of the tracks that allow visitors access to the reserve. Ever botanising, he points out plants of interest as we pass. He surprises me by saying that of the 240 naturalised exotic plants on Banks Peninsula, the trust worries about only four. “We completely live with 236 of them,” he says. “Sycamore is the most serious threat. So serious we blat it as soon as we find it.” Old man’s beard, an introduced clematis, is another.
Wilson has been called a “tree whisperer”, and he looks the part of a man in tune with his environment. Even more than that, a man who organises his life around his environment. Wool shirt and whiskers, shorts and gumboots, a hand mower parked outside the back door and a bicycle leaning against a wall. On his dining-room table, stacks of scientific papers, botanical monographs and a daily weather log. In one corner of the living room, a plant press. In the other, several recorders—the musical sort—and, pinned to a noticeboard, a Polish folk saying that could serve as Hinewai’s motto: “We were not here but the forest was. We will not be here but the forest will be.”
At the entrance to the reserve, a sign on the gate says in large block letters, “On foot only”. Underneath, in slightly smaller capitals, are the words, “Essential service vehicles only”, and underneath that, in smaller letters again, “In the language of this place, the likelihood of a vehicle being ‘essential’ is so low as to be near zero”.
I tell Wilson I like the idea of a language of place, and that I’m trying to become more fluent in that tongue. At the lookout, he tells me that Banks Peninsula was once forested “from side to side and top to bottom”. By 1900, less than one per cent of the old-growth forest remained, and that remnant was logged intermittently until the 1920s. “Now native forest covers 15 per cent of the peninsula,” says Wilson. “That’s without any human help at all. That’s achieved by nature against all odds. Farmers kept trying to clear the gullies but couldn’t keep up with the regeneration.” Many have now fenced off their more marginal land and are embracing native regrowth.
With additional land purchases, Hinewai itself has grown to 1250 hectares over the past 25 years, and Wilson and White’s dream of summit-to-sea restoration is being realised. We gaze at a mosaic of moss-green, grey-green and gold on the face of a regenerating hillside. The gold is gorse, the moss-green is mahoe, a quick regenerator in this climate, and the grey-green is kanuka, another excellent nurse species. Wilson says there’s a colonisation contest between gorse and kanuka, each vying to get established on open ground. The one that wins out affects the course of forest succession for 100 years. “People don’t realise how subtle the environment is. You only have to make a small change and animals and plants react.”
I tell him I’m heartened that increasing numbers of people seem willing to make their own small changes to give indigenous nature a better chance of surviving and thriving. Planting natives, controlling predators, protecting forest remnants, attacking weeds, cleaning up waterways—there seems to be a groundswell of interest in such community-based restoration projects. People are learning the language of place—what it means to be conversant with the land, rather than indifferent to its needs.
The forests of Hinewai, or Deans Bush, or Waipoua, or Pureora, are good places to learn the dialects of nature. So, too, is a patch of mangroves or a creekside planting in suburbia. Wilson agrees that it’s not the scale that is important, but the intent. “Some people will change the world. Some people will change a valley. Some people will change their back yard. That’s how it’s going to happen.”