Pirongia Forest Park has many walks and spectacular views

Forest and Bird, Volume 14, Issue 3, 1 August 1982, Page 29

Pirongia Forest Park has many walks and spectacular views

By

Journalist to the Forest Service

Catherine Chapman,

PIRONGIA FOREST PARK lies about 25 km south-west of Hamilton, between the main roads to the popular west coast holiday resorts of Raglan and Kawhia. The park was gazetted in 1971. Its total area is about 14.000 ha. A main block covers Mount Pirongia (926 m) and a large tract of hill country beyond its north-west flank, and a minor, outlying block contains the smaller Mount Karioi (760 m) just south of Raglan.

THE VERY STEEP, bushclad ridges, the great gulches, and stark rock outcrops of Pirongia form an_ arresting backdrop of wilderness to the pleasant rural landscape of the Waikato plains and downlands. Over a century ago the famous Austrian explorer and geologist von Hochstetter remarked: ‘*‘The .eye. never tires Of (gazing at. it; as. At always assumes new _ forms from each point of view."’ Maori traditions The looming presence of this rugged mountain and the frequency of ominous swirling fogs and violent thunder storms about the highest peaks make it easy to appreciate the significant place it has in Maori traditions. It was a citadel of the fairy folk — the patupaiarehe — and strange tales are still remembered of the Tainui people who encountered them in the mountain forests. The name Pirongia is derived from Pirongia-te-Aroaro-o-Kahu, which may be translated as ‘‘the scented presence of Kahu’’. Kahupeka, the wife of Ue, was said to have been anointed with fragrant oil from: crushed: leaves: of rangiora as she rested during a journey over the mountain some 500 years ago.

Park headquarters Pirongia township, where the park headquarters and information centre are, was formerly a busy military post during the Maori-European land wars. The township thrived until the 1860s, but began to decline, particularly when it was by-passed by the main trunk railway line. Timber was removed from the lower slopes of Pirongia and Mount Karioi in the late 1800s and early 1900s as land was cleared for farming. Grass and scrub areas within the park today show where land clearing was attempted at higher altitudes. Steady trudge The summit of Mount Pirongia is today no more than a morning’s steady trudge up a good track from a road end at the eastern forest edge. On a clear day a splendid view rewards the climber — along the west coast north to Manukau Heads, eastward over the Waikato and Thames Valley farmlands to the great wall of the Coromandel and Kaimai Ranges, and _ south-

ward across the King Country to the distant Kaimanawa Range, Mount Ruapehu, and Mount Egmont. The noted botanist T. F. Cheeseman enthused over this view in his account of his pioneer ascents of Pirongia in 1877 and 1879. However, on trying to reach the western peak known as The Cone, only a trifle lower than Pirongia trig point, Cheeseman and his Maori guide found the montane scrub too difficult to penetrate and gave up the attempt. Mount Pirongia is a longinactive and strongly eroded basalt volcanic cone, with very deep, plunging radial gullies separated by knife-edged ridges in places, especially on the south side. Below about 600 m the cone has a wide, gradually sloping fringe made up of old lava flows and volcanic agglomerate; the ridges become very broad and the gully floors generally wider. That sort of terrain is, however, included within the park to any great extent only below the north face of the mountain. To the west of that area the park covers the last substantial remnant of virgin native forest on the greywacke hills between the Pirongia and Karioi volcanic fields. The highest point in this hill country, Koponui

(about 560 m), is actually an isolated basalt outcrop. Mount Karioi is generally a replica of the Pirongia cone, but as it is only 760 m high, it does not have some of the plants founds on the uppermost parts of Pirongia. The typical soils on both these residual volcanoes are brown to red-brown loams and brown granular clay loams, derived from deep weathering of the basalt rock (and, on Karioi, of andesite). On the generally steep hillsides of the greywacke country grey-brown to yellow-brown clay loams predominate on top of blocky clay and weathering rock fragments. However, on the fairly wide and rounded ridge tops, indicative of a former plateau surface, more friable soils are derived from a series of deposits of volcanic ash. This was not emptied from Pirongia or Karioi, but from the rhyolite volcanic centres about Taupo and Rotorua. Vegetation The forest below 600 m in the main block is typical of the southern Waikato: mixed hardwood forest with scattered podocarps and a fairly wide range of shrubs, ferns, vines, and epiphytes. The kauri, taraire, puriri, and hard beech of the northern Waikato are entirely lacking, though the ‘‘tree’? coprosma (Coprosma arborea or mamangi) reaches its southern limit here. The largest trees are rimu, miro, and rata, with most of the last-named unfortunately now dead or dying. They stand out above generally abundant tawa and kamahi, hinau, rewarewa, mangeao, pukatea, and kohekohe. The _ underwood is dominated by mahoe, pigeonwood, tree ferns, and in places nikau palms. On the wider gully floors pukatea becomes very com-

mon, with some large kahikatea, whereas on the narrowest ridges the main hardwoods are kamahi and rewarewa. There is some tanekaha, and heketara and tawheowheo are the commonest shrubs. Kamahi forms almost pure stands on the exposed ridges leading to Koponui Trig. Some of the most attractive native flowering shrubs occur in this lower forest — for example, lacebark, toropapa, taurepo, rangiora, and fuchsia. The flowering vines include not only the New Zealand passionfruit (kohia) and the common ratas, but also the very rare Metrosideros carminea. The dainty vivid-green fern Lindsaea viridis may be seen along streamsides, and the giant-fronded king fern (para) is in some damp gully recesses. Also to be found are the unusual ‘‘five-finger’’ Pseudopanax laetus with very large leaves and purplish-red leaf stalks, and hutu, a _ toothleaved shrub with purplish branchlets which is most uncommon outside Westland. Between 600 and 800 m on Mount Pirongia the forest changes by degrees as lowland plants drop out. Hardier ones take their place as increasing cloudiness, coolness, rainfall, exposure to the _ prevailing strong westerly wind, and steepening terrain and_ shallowing soil all have their effect. On the highest ridges and faces the vegetation is only 8 m high at best and some of it is a mere low scrub. The conspicuous larger plants are kamahi, tawheowheo, tawari, broadleaf, haumakaroa, toro, stinkwood, horopito, neinei, toi, and mountain flax, with some stunted Hall’s totara hardly peeping above the interlaced wind-shorn canopy. In comparison with the Coromandel and Kaimai Ranges

there is a rather surprising dearth of southern elements of the New Zealand flora on the summit of this mountain. There are, for instance, no mountain toatoa, yellow-silver pine, pink pine, or beeches. Kaikawaka trees occur in patches along the topmost ridges, from about Bald Spur to The Cone. Some, in sheltered spots, are quite large trees, their boles mantled by the large hanging moss Weymouthia mollis and myriads of small ferns. In the 1880s the first survey party on Pirongia was delighted to find a handy kaikawaka to fell and use for the first trig post. Southern rata also occurs on the mountain top, but is extremely rare. Goats, opossums, cattle, and pigs have over decades wrought considerable damage in parts of the park, but it does appear that strenuous control efforts are beginning to reverse the trend. The lower forest in the Karioi outlier is similar to that on the main block, except that kohekohe is more plentiful. In sheltered gullies above 500 m rata, tawa, rewarewa, and mangeao are scattered among dense mixtures of kamahi, mahoe, heketara, rangiora, and fuchsia. On the almost continually wind-blasted rough ridges there is dense low forest or scrub like that on Mount Pirongia, though tawari, kaikawaka, and southern rata all seem to be absent. Wildlife Various birds are present throughout the park, though it is likely that populations have changed as a result of losses through mustelids, cats, and rats and the early milling and clearing of land for farming. Kingfisher, harrier hawk, and New Zealand pipit inhabit the border areas of forest and

farm , land, . and , on the lower slopes tomtits, grey warblers, fantails, native wood pigeons, tuis, and bellbirds are often seen. At higher altitudes flocks of whitehead are common. Moreporks are heard at night, and kiwis are occasionally heard, particularly in the west of the park. Shining cuckoo, long-tailed cuckoo, silvereye, pied tit, kokako, and rifleman are present, but blue mountain duck, kaka, and parakeet have only rarely been sighted in recent years. New Zealand falcon are sometimes seen on the higher peaks. Introduced birds seen in the bush and surrounds include chaffinch, thrush, blackbird, rosella, magpie, sparrow, and skylark. In the streams long- and short-finned eels, bullies, and freshwater crayfish are found. Introduced animals Feral goats are found on the fringes of the forest and have penetrated into the headwaters of most streams. Forest Service culling programmes are carried out from time to time and recreational hunting for both goats and wild pigs is encouraged. Opossums have spread throughout the park, possibly aided by forest depletion from goat browsing. Commercial hunters and trappers in the park submit high returns of skins. Small mammals such as mustelids, feral cats, hedgehogs, rats, and mice are present. The carnivores prey on birdlife, and the rodents probably compete with indigenous wildlife for the available fruit and berries. Management The main aim of management is the safeguarding of soil and water, and the Mangauika catchment is specifically zoned

for soil and water protection for the Te Awamutu water supply. No overnight camping is allowed in this area, and permits are needed to enter it. The entire Oparau_ River catchment within the park is protected in an ecological area of some 2100 ha. It contains large representative segments of each of the two main and strongly contrasting landscapes. in: the--.park.: The primary use zoning for the rest of the park is for natural environment recreation. Pirongia Forest Park is within easy distance of the major population centres of Hamilton and Auckland, and it is expected that recreational use of the park will increase. An extensive system of tracks has been developed in the park during the last 10 years, with walks and tramps ranging from less than an hour to 8 hours. It is possible to plan a 2-day walking tour with an overnight stop at Central Hut. Most tracks lead up to the mountains and consequently provide spectacular views of the surrounding countryside. Access is probably the most difficult problem in_ recreational management of the park. Only one road — Pirongia West No. 1 Road in the south-west — leads to the park boundary. All other access is by track, and most tracks cross privately owned farm land before entering the park. These routes are available only through the generosity of the landowners. The Forest Service is continuing negotiations for formalised access routes. A four-bunk hut at Smiths Clearing and an emergency shelter between The Cone and Mount Pirongia provide refuge for those caught in the park in bad weather. The hut has been continually vandalised in recent years, and this is a source

of worry to park managers. The shelter, previously known as Hihikiwi Shelter, has been renamed Pahautea after the patches of very old North Island mountain cedar trees in the area. An area of 4500 ha in the north-west of the park is recognised as having longterm potential for wood production. However, this is not compatible with the primary zoning of most of the park for natural environment, and no production is planned. In 1976 an application for prospecting over the entire park was received by the Forest Service. This was thoroughly examined and after opposition from the park advisory committee and the public the application was withdrawn. There are six grazing leases within the park, each of which will be reviewed during the next 10 years. Recreation The major recreational activity is tramping, with some goat and pig hunting. Opportunities for family groups and the elderly to use the park are limited at present, and until access problems are resolved development of short walks and picnic sites cannot be undertaken. Boots or very sturdy shoes should be worn on all tracks. Sudden changes of weather can occur at any time of year, and visitors should be prepared for these with suitable clothing and provisions. Park staff ask that people visiting the park call at the headquarters at Pirongia for information about the tracks before setting out. Search and rescue operations frequently have to be mounted for people who have strayed from the tracks; so those unfamiliar with the area should keep to the marked routes. im