BULLER RESERVES: Custodians of time's secrets

Forest and Bird, Volume 16, Issue 1, 1 February 1985, Page 8

BULLER RESERVES: Custodians of time's secrets

by

and

NFAC Researchers

Peter Grant

Annette Lees,

| ike the prow of a ship, a ridge of virgin forest between two waterways extends out from the Paparoa mountains onto a desolate sea of logged forest and exotic plantings — such is the area bounded by the Atbara Creek and Nile River in Buller, one of two regions on the West Coast lately singled out by the Joint Campaign on Native Forests for protection. The other is the Ngakawau Forest, north of Westport, featuring a dramatic gorge, wind-swept coal plateau and a high perched basin of podocarp/beech forest.

In the wake of a recommendation by the State Forests Scientific Reserves Advisory Committee that existing forest reserves in Buller are inadequate, the Joint Campaign has produced scientific reports highlighting just why these two areas are so special. The Atbara-Nile Just to the north of the proposed Punakaiki National Park lie.the Atbara Creek and Nile River, their sources high in the rugged Paparoa mountains. The

visitor enters the area off the WestportGreymouth highway a little south of Charleston, reaching the virgin forest by following along, winding gravel road, surrounded by forest in various stages of recovery from recent devastation. In the once splendid valley of the Nile, logging roads run in all directions, completely enclosing the still-untouched proposed reserve. Just to the south is the devastated Tiropahi Ridge, thrust like a dagger into the heart of the Paparoa forests. Peering out from the young pines on the ridge, across to the virgin forests of the AtbaraNile, one begins to see why it is so unique. In ancient times, during the tumultuous Pleistocene ice ages, the sea reached far inland, and would have lapped at the Tiropahi ridge just below one’s feet, cutting out and depositing wide flat beaches around the toes of the hills. In cold, icy periods the sea level dropped, leaving the newly formed beaches and river terraces stranded. While this was happening, the land was being slowly uplifted, so that the terraces were carried high enough to protect them from the next ice melt and rise in sea level. Six times the sea and rivers rose and cut out terraces, and each time like a moving escalator the terraces were raised a little higher. , The terraces have remained to this day, the oldest ones now standing 190 metres above sea level. They have been dubbed the Candlelight, Whiskey, Caledonian, Addison, Virgin Flat, Waites and Speargrass terraces. The present day beaches and rivers form what is known as the Nile Mile Terrace. In time the oldest of them have been leached of nutrients, supporting hardy trees adapted to thinner soils: mountain beech, silver pine and mountain toatoa are common. The youngest terraces, by comparison, freshly coated with rich river silts and marine sediments, bristle with tall podocarps and beeches, and are lush with flowering plants, ferns and mosses. Cupped between the Atbara and the Nile are three of the younger marine terraces — the Speargrass, Nile Mile and Addison — which are not represented in any other protected area, or in the proposed Punakaiki National Park. Here is the last chance to preserve a complete sequence of these terraces, each offering a bounty of hidden information about forest ecology and the changing patterns of time. Sad mosaic of ravaged landscapes From low marine terraces to icy mountains, the proposed Atbara-Nile Ecological Reserve would be spectacular and important. The forest falls between two ecological districts, Punakaiki in the south and Foulwind in the north. The aim of dividing New Zealand into ecological districts — that each district should have examples of unmodified environment protected in reserves — has not

yet been achieved in Buller. The Foulwind district is a sad mosaic of plundered landscapes, with only three meagre scenic reserves. The proposed Atbara-Nile reserve spills across into the Foulwind district and would add to it a magnificent virgin example of an otherwise lost ecology. To the south, the Punakaiki ecological district encompasses the Tiropahi reserve, which includes three high marine terraces. Unfortunately these were logged and cleared many years ago. The nearby, Atbara-Nile proposal would complete the terrace sequence, and would do so far better — by providing virgin forested examples of the distinctive landforms. The Ngakawau — grandeur and variety The forests growing over the mountains and plateau of the Ngakawau ecological district are stunning, both for their grandeur and their variety. To the east is the high Glasgow Range, stepping down to a broad plateau, the slopes of which fall away to the sea and to the Buller River. The dramatic cleavage of the Ngakawau Gorge splits the plateau in two, as the Ngakawau River has cut through coal measures and siltstone to the ancient bed beneath. Behind this plateau, the Ngakawau catchment opens out into a huge basin, draining streams flowing off the Glasgow and William Ranges. High on the range tops grow natural scrublands and grasslands -communities which appear again on cold swampy areas of the plateau under the mountains’ shadows. Tall podocarp-beech forests grow in the amphitheatre of the Ngakawau’s basin, standing on the narrow steps of rich river terraces. Although cut away during the same glacial times that formed the AtbaraNile terraces, these differ as they are about 400 metres above the ocean and were unaffected by the erasing powers of a rising sea level. The older terraces are worn by leaching and erosion, with the highest a rare natural pakihi wetland. Closer to the coast, wind-swept coal measures support a stunted and strange vegetation. Plants that grow here are especially adapted to survive in the toxins of coal-rich soil. The measures reach to the rim of the Ngakawau gorge cliffs, then stop. In the cool shelter of the river cleft grow aremarkable assortment of extremely rare plants, ferns, forest herbs and shrubs. Among these is Celmisia morganit, a mountain daisy now known only from the Ngakawau River. Giant carnivorous snails, Powelliphanta, populate the leaf litter on the plateau floor, and in the forest canopy live many bird species — kaka, parakeets, kiwis, robins.

Urgent plea for protection In response to requests from conservationists and Government agencies responsible for conservation, the Forest Service has proposed two reserves — _ the Ngakawau and Orikaka ecological areas, which preserve some features but not the important tall forests of the Ngakawau basin, nor the continuum to the Glasgow tops or the coastal forest fringe. In 1976 the Scientific Co-ordinating Committee proposed to protect the whole of the Ngakawau forest and its inland basin forests, but this was later greatly reduced because of Government pressure to release rimu sawlogs for the dilapidated Waimangaroa sawmill. Today, the grand forests of the Ngakawau basin are still untouched, but much of the northern plateau is being clearfelled, burnt and planted in pines. Survey pegs are in the ground for a proposed logging road that would thrust right into the heart of the proposed reserve. The Joint Campaign on Native Forests ts fighting hard against the logging road. The original proposal should go ahead, and extend to the tops of the Glasgow Range, thus linking the Ngakawau ecological area to the Orikaka, and providing the large forest tract asked for by the Wildlife Service. To the north, a separate circle of forest should be set aside to protect a Powelliphanta population, while an outlier reserve near the summit of Mt Augustus would protect the unique plants growing there. For visitors, the area divides into two. The lower Ngakawau Gorge, featuring the beautiful Mangatini waterfall and the historic remains of an old coal mine railway, is readily accessible for family groups via the Charming Creek railway. The upper catchment, on the other hand, with its deep gorge, basin forests, river flats and Glasgow Range peaks, is more remote and challenging. At present, the lower gorge is controlled by Lands and Survey and the rest of the catchment by Forest Service. If the upper catchment can be reserved, there is merit in the Forest Service controlling the whole area. And what about jobs in the timber industry? Guy Salmon pointed the way to rationalisation of the Buller industry in the August 1982 issue of Forest and Bird. He argued that more jobs should be created in wood processing as opposed to cutting down trees; tourist development and making effective use of already cleared land were also preferred options. The timber industry could also make use of hard beech trees currently wasted in rimu logging. Further reading: copies of the two scientific reports on these reserve proposals are available for $5 each from the Joint Campaign on Native Forests, PO Box 756, Nelson. oe