The 20ha public reserve in Gards Rd, Waitaki Valley, is so new it is yet to be named. But the limestone outcrop's spectacular scenery, rare and endangered plants, 25-million-year-old fossils and evidence of early Maori occupation mean it will not remain the exclusive preserve of conservationists and researchers for long, writes Bruce Munro.
Graeme Loh's legs straddle a steeply sloping spur of the 20m-high limestone escarpment. Spread out below him tree-lined emerald paddocks stretch across the broad valley floor towards glistening braids of the Waitaki River, and beyond to the jagged St Mary's and Kirkliston ranges. But right now the conservation ranger only has eyes for a spindly, light-green clump of vegetation one metre further down the cliff.
It is one of seven naturally occurring specimens of the critically endangered native broom (Carmichaelia hollowayi) that have been found on this 20ha limestone outcrop - one of only three locations in New Zealand where it maintains a tenuous toehold.
''We don't know if where they are, here on the edge of the clifftops, is their preferred habitat or their last refuge,'' Mr Loh says.
Three hours ago, Mr Loh was nosing his Department of Conservation (Doc) 4WD utility off SH 1 at Maheno, south of Oamaru, pushing northwest, away from the coastal Otago drizzle towards the clearer skies of the Waitaki Valley. When he pulled in to rural Gards Rd, between Duntroon and Kurow, 40 minutes later, New Zealand's newest Doc-administered public reserve lay spread out in front of him, its pavlova-coloured cliffs bright in the sunshine.
It was less than four months since the purchase of this, the first lowland reserve in the Waitaki Valley, was announced by Minister of Conservation Nick Smith. Mr Loh had been instrumental in negotiations that led to the $200,000 Nature Heritage Fund acquisition to ensure good care of, and public access to, this site replete with botanical, geological and cultural significance.
By the end of the year he hopes the reserve, which is already open to the public, will have signage, a walkway, and carparking. But today he is here to give the Otago Daily Times a personalised tour and to continue his deeply felt battle against boxthorn, the spiked pest plant that had infested the outcrop's lower reaches.
''Pure hatred and determined opposition,'' Mr Loh says, uprooting, chopping and spraying the African exotic as he leads the way up the eastern edge of the hill.
''It competes with the native broom for space and water and also breaks the cliff apart.
''We're making good progress eradicating it, but you have to kill it three times because it keeps growing back.''
Nearing the top, Mr Loh points out layers of fossilised seashells embedded in the soft rock and, further along a sheep track that ends in a rock overhang, the oval cross-sections of two small fossil penguin bones.
This hill we are walking across is the important remnant of an ancient sea floor.
More than 20 million years ago a good portion of present-day New Zealand was covered in a shallow warm ocean. Here the predecessors of today's fish and marine birds and mammals lived and died, their skeletons embedded in successive layers of marine sediment.
Many millennia later the proto-Waitaki River rushed across this landscape towards the now more distant coast, scouring millions of years of sediment as it formed and reformed its banks.
Left behind by chance was this island of limestone which has become a significant record of the Miocene period. Its cliffs are a multi-storeyed chronological record of life here between 23 million and 25 million years ago. But we will see more evidence of that later, Mr Loh promises as he traces the grassed tops of bluffs in search of rare plants.
Under a chicken-wire covering is a propagated example of the critically endangered native broom which first alerted Doc to the significance of this site about 20 years ago.
It was in order to protect the small handful of remaining hollowayi on this escarpment that Mr Loh began negotiations with landowners Dave and Gert (Lorraine) Parker early in the new millennium. Added impetus came from Meridian Energy's later-abandoned proposal to run its controversial Project Aqua hydroelectricity canal across the foot of the cliffs.
Since then Mr Loh and colleagues had also found more rare plants, and had come to realise the importance of other plants they knew grew here.
One large clifftop ''bay'' is home to specimens of most of the reserve's plant wonders. And Mr Loh is a fountain of knowledge on each of them.
This 20ha patch is the single largest known population of the tiny fern-like native cress Lepidium sisymbrioides. The cress is part of the brassica family and is a potentially valuable genetic resource that could help protect future economic crops, he says.
Two metres down a vertical slab of west-facing cliff are two pink cardboard triangles pointing at small splotches of white, the flowers of an unnamed gentian. The two plants were discovered in 2009 and last year. Seeds they have produced will be grown and tested so they can be properly identified.
A prostrate kowhai, Sophora prostrata, hugging the contours of the clifftop is not endangered but neither is it common, Loh says. The large, long-lasting flowers this variety produces have seen it crossed with tree kowhai, the result now adorning gardens throughout New Zealand and around the world.
And so the tour has arrived at the other side of the ''bay'' where Mr Loh is climbing ever-further out and down a spur to examine one of the native brooms.
''My aim is to get these endangered plants on a secure footing,'' he says.
''It's part of the character and the fascinating story of New Zealand.
''And I enjoy discovering things ... trying to find out where life came from and what New Zealand was like before we humans arrived.''
Our flora is quite different from that found in other parts of the world. A key reason is thought to be the presence of huge herbivorous birds in pre-human New Zealand, filling the niche occupied elsewhere by mammal herbivores, he says.
''The prostrate kowhai are an excellent example of signature adaptations to bird browsing - they have a high tensile strength; you can't pull them apart easily. They have small leaves, and dull leaves because birds have good colour vision.''
Mr Loh makes his way carefully back up to the clifftop and suggests a walk across former hillside grazing land to the brow of the hill. The downward-sloping southern flank of the reserve merges with green pastures leading to vineyards at the foot of hills and mountains dominated by lofty, snow-capped Mt Domett. There were plans for those vineyards to extend to this outcrop, Mr Loh says. The legal wrangle that ensued between the developers and the landowners put Doc's negotiations to purchase the land on hold for several years. But that is the Parker's story to tell, he says.
The lower slopes of the western end of the reserve show signs of a recent battle between a large stand of boxthorn and energetic volunteers. Mr Loh is pleased to report the volunteers scored a substantial victory despite the toll taken on their chainsaws.
Working his way eastwards across the bottom of the bluff, Mr Loh points out a 50 cu cm hole in the limestone at about waist height. It is where geologists removed an exposed fossil skeleton of a marine mammal. Being this low down on the cliff, it was probably 25 million years old.
A natural path leads between the cliff and an enormous chunk of fallen limestone. On the boulder are inscribed the names of University of Otago geology Prof Ewan Fordyce and three colleagues beneath the message ''Fossil whale collected 17-18 October 198''. The full date has been worn away. High up on the facing cliff, beneath an overhang, large fossilised bones can be seen.
Later on, when contacted by the ODT, Prof Fordyce would say he thought the expedition was in 1989. He has never been able to get close enough to the fossil in the overhang to be sure but believes it is part of the vertebrae of a whale.
The Gards Rd site has been an important location for Prof Fordyce's studies, offering up fossil remains of bony fish, sharks, penguins, whales and dolphins. He is, however, a firm supporter of the new reserve.
''I've always been torn when I go to these nice localities and see a specimen and I think `That would be scientifically important but what sort of an impact is it going to make for us to get it out?'.
''Often I've found material and just left it in place.
''I think this [reserve] is a great initiative ... it will really help people understand more about our geological heritage.''
The most recent concrete evidence these cliffs were used by Maori in pre-European times was found just metres from where we stand, Mr Loh says.
Archaeologists as far back as the 1870s had described an ''overhang shelter'' here - a resting spot during journeys inland to collect food and items for use and trade. But there was ''a bit of a gold rush'' for Maori artefacts in the Victorian era by people who ''didn't give a damn about the story behind them''. As a result, only a few artefacts have been found here in recent times, he says.
''About two years ago, when we were clearing boxthorn here one of our volunteers found an argillite chisel ... That argillite most likely came from near Riverton or it might have come from Stephens Island in the Marlborough Sounds.''
Contacted later, archaeologist and rock-art specialist Brian Allingham says no rock art has been found at the site, perhaps because the limestone is so soft any drawings have worn away.
Mr Allingham says evidence of occupation found in recent years includes cooking stones, the unfinished adze-like tool mentioned by Mr Loh, and flakes of quartzite used for making tools which probably came from quarries further up the valley.
Because of their pre-colonial connection with the area, members of Ngai Tahu's Moeraki runanga have been asked to choose a name for the public reserve.
We are now running late for an appointment with the former owners, Mr and Mrs Parker, whose farmhouse is just across the road from the outcrop.
The Parkers have always been supportive and ''amazingly generous'', Mr Loh says.
Large servings of a delicious moist carrot cake suggest he is correct.
The family has farmed in the area for 80 years, Mr Parker says.
His father bought the land that includes the outcrop 30 years ago, and Mr Parker has worked the 600ha farm for the past 25 years.
The foot of the cliffs provided good shelter for newly shorn sheep when a southerly was blowing. But he has had fewer sheep in recent years and now primarily provides dairy support.
Their son Hayden would like to return to the farm, Mrs Parker says.
The couple do not want to say much about the historic dispute with developers, beyond confirming it was the first case to go to New Zealand's Supreme Court and that it came down to a precedent-setting decision on whether personal cheques were legal tender, which went in their favour.
Mr Parker was always aware of the geological and archaeological features of the area. He and his siblings and friends used to play on the outcrop as youngsters and found disused Maori ovens in cliffs on the northern side of the Waitaki Valley.
It has not been an easy decision to sell the outcrop, Mr Parker says.
''I liked the fact it was part of the identity of the farm ... Once something is sold, that can be it forever. Well, this one will be, won't it.''
But over the years Mr Loh has informed and ''ignited'' the Parkers' interest in the plants on the site.
''When you start to say there's only two other places in New Zealand there's these plants,'' Mr Parker says.
''I thought holy hell, New Zealand is a big place and there's lots of plants in New Zealand.''
In the end they have decided to sell so that the land can become a properly administered public reserve, reasoning that even if they do not own the site, no-one can remove it.
''They [researchers and conservationists] are so excited about it,'' Mrs Parker says.
''And it's nice to be able to preserve it for future generations too.''
