|Publisher:||Auckland University Press|
|Sold by:||Barnes & Noble|
|File size:||94 MB|
|Note:||This product may take a few minutes to download.|
About the Author
Read an Excerpt
A Natural and Cultural History
By Philip Simpson
Auckland University PressCopyright © 2017 Philip Simpson
All rights reserved.
Totara in the natural world
What is a Totara and where does it fit in the natural world? Maori came to revere the wonderful timber for carving and building, and described the forest giants as rakau rangatira – 'chiefly trees'. Europeans shared the enthusiasm for the timber and used it to build their farms and houses. Botanists identified its relationships with other conifers, noting its soft, resinous wood, its tough needle leaves, and, like the cherished yew, its fleshy, red-footed seed. To understand totara, we need to place it alongside its ancestors and relatives in New Zealand and further afield.
Those ancestors are the gymnosperms – the world's first seed-bearing plants, of which the conifers are the most dominant group. Conifers preceded the flowering plants in the history of life on earth, and, though the latter have now far surpassed them in diversity, the conifers seem to do very well in the modern world. Totara is a case in point. It belongs in the Podocarpaceae, the dominant family of southern hemisphere conifers. Although podocarps are ancient, they are now diverse, widespread and still actively forming new species, especially in tropical mountains. We will see how totara exhibits gymnosperm, conifer and podocarp features, but is also uniquely adapted to present-day New Zealand forest.
DISCOVERING AND NAMING TOTARA
Maori brought the name with them from Polynesia. There, several things were called totara, including the spiny-bodied fishes known as porcupinefish. In Aotearoa, tara refers to things that are sharply pointed, like the rays of the sun, or the peak of a mountain. Some birds, such as the various species of tern (Sterna species), are named tara because of their finely tapering wings. Some plants include tara as part of their name, such as tataramoa, the infamous prickly bush lawyer (Rubus cissoides), and taramea, the viciously sharp speargrass (Aciphylla species).
So 'the tree with the very straight trunk' (to), or 'that which possesses the sharply pointed leaves', became totara. Totara is also the name of a New Zealand moss, Polytrichum juniperinum, and a number of other species include totara in their names. New Zealand has its own porcupinefish (Tragulichthys jaculiferus), named koputotara or kokopu totarawhare. Totaramoana is the name of a totara tree-like black coral that was dredged from deep water and used to form fish-hooks. Patotara is the name of an unusual fern (Botrychium spp.) whose single frond looks like the broad crown of a totara tree in miniature, and which is also sterile (the fertility is 'obstructed', like a palisaded pa). Hard mingimingi (Leptecophylla juniperina) was also named patotara because of the sometimes great difficulty of moving through dense groves of this shrub owing to its tough, unyielding branches and needle-like leaves. Maori gave the name totara papa ('flat growing') to its diminutive relative Leucopogon fraseri.
THE NEW ZEALAND TOTARA SPECIES
Soon after the first Pakeha arrived, they began to rediscover and rename totara in scientific terms. In 1826, English botanist Allan Cunningham, to whom Joseph Banks had given the charge of collecting plants for the Royal Botanic Gardens at Kew, collected the first traceable herbarium specimen of lowland totara from the Bay of Islands. First to describe a specimen was English naturalist George Bennett, who visited the Bay of Islands in 1829 and whose specimens are now housed in the British Museum, London. Bennett wrote his notes on totara from observations along the Kawakawa River, where Cunningham had been a few years before. Podocarpus totara was the first New Zealand plant to have its Maori name formally adopted as the species name. The botanical description reads as follows:
Podocarpus? Totara, foliis undique versis linearilanceolatus mucronatis subtus glaucus. Dacrydium taxifolium. Solander MSS. Habitat in Nova-Zelandia. D. [sic] Bennett. Totara indigenis.
At that time, formal botanical descriptions were written in Latin, and this translates to 'leaves flattened, narrow, slightly broadened, with a sharp tip, blue-green underneath'. The description seems to imply that totara was called Dacrydium taxifolium in the unpublished Solander manuscript from Cook's first voyage. David Don, a Scottish botanist, wrote this description, so the formal name for lowland totara is 'Podocarpus totara G. Bennett ex D. Don'.
In 1838, Captain William Symons introduced a living totara to Kew, while the visiting French naturalist Etienne Raoul collected totara from Banks Peninsula in 1843. These specimens enabled Sir William Hooker, director at Kew, to make a full description and an excellent illustration of totara, including the cones. His son, Joseph Dalton Hooker, who would succeed him at Kew, noted that totara was cultivated in England by 1853 (probably from plants brought to Kew by Cunningham). In the first comprehensive book on the New Zealand flora, Joseph Hooker states that totara wood is 'the most valuable in the islands'.
Early botanists initially regarded other specimens of totara as mere varieties of lowland totara, but eventually four more species, and one variety (a formally recognised category within a species), were identified. Snow totara (Podocarpus nivalis) was first collected by John Bidwill, naturalist for the New Zealand Company, when he climbed Mt Ngauruhoe in 1839. Thomas Kirk, appointed chief conservator of forests in 1885, was the first to describe the 'acute-leaved totara', now commonly known as the needle-leaved totara (P. acutifolius), and later published detailed accounts of all the totara species.
William Colenso collected a specimen of another species during one of his renowned crossings of the Ruahine Range in the 1840s and named it P. cunninghamii; it was also collected by William Hall from the Coromandel Peninsula, and described as P. hallii by Thomas Kirk. Recently it has been discovered that a specimen described in 1847, and cryptically labelled as coming from Australia, is in fact this species, and was named P. laetus, a reference to the healthy-looking foliage, especially of the juvenile: laetus is now regarded as the valid name.
Another significant taxonomic change is the identification of the South Westland totara as a hybrid and its recognition as a distinct variety of lowland totara, Podocarpus totara var. waihoensis, as explained below.
Those four species – lowland totara, Hall's totara, needle-leaved totara and snow totara – and the waihoensis variety make up the New Zealand totara.
Lowland totara, Podocarpus totara
Lowland totara is the 'big tree' of the podocarps. Mature individuals, at least in pre-European times, grew well over 40 metres tall and had trunks up to 4 metres in diameter. With its scarred crowns from the many storms it has experienced, and the deeply furrowed, red-brown bark, an old lowland totara is an impressive tree. And a pure, old-growth stand is a wonder to behold. Lowland totara vigorously regenerates in alluvial plains and valleys or on fertile hills, and creates some of the finest rural landscapes in New Zealand. It is distributed throughout the country, usually below 600 metres altitude, but is rare on infertile soil. In cold, wet places, such as Westland and Southland, it is mostly restricted to coastal sand and the lowland habitat supports Hall's totara instead.
When people speak of 'totara', they are usually referring to lowland totara. Sometimes it has been called true totara, but 'lowland totara' is a better name because the tree is the characteristic lowland podocarp in most parts of New Zealand.
Hall's totara, Podocarpus laetus
Hall's totara is sometimes called paper-barked totara (totara kotukutuku – 'the totara with bark like that of the tree fuchsia') or thin-barked totara. However, bark is an unreliable diagnostic characteristic owing to widespread hybridisation with lowland totara, as well as natural variation. It is also often called mountain totara because it is usually montane through most of its considerable range – it grows across nearly 13 degrees of latitude, from North Cape to South Cape. On poor soil, however, or in wet places or cool latitudes, it can be a lowland tree, even to sea level. Bushmen have identified the timber as 'white totara'. It is, however, widely known as Hall's totara, and I have been encouraged to use the name.
Mature Hall's totara are generally smaller than lowland totara, but they can be very large in some places. Trees growing in the open are strongly conical, the trunk tapering from a broad base. The leaves of juveniles are impressively large, sometimes 4–5 centimetres long, narrowing to a very sharp point from a broad base. Adult leaves are much smaller, and at their broadest in the middle. The reversion shoots emerging from the lower trunk or after injury are often of the juvenile type.
Leaf differences aside, separating Hall's and lowland totara can be very difficult because both are quite variable. The resting buds differ: in Hall's, they are broad and round, while in lowland they are narrower and pointed. The seeds of Hall's totara are strongly elongated, compared with the almost spherical seeds of lowland totara. Owing to hybridisation, however, many lowland totara seeds have a short, pointed crest. Because it seems impossible to separate the two species in some locations some botanists have advocated the concept of a 'coenospecies' (from the Greek koinos, meaning 'in common' or 'shared'). A better solution, however, is to recognise that the two species are sometimes linked by hybrids.
Hall's totara is shade-tolerant and often is found under a beech canopy, 'waiting' for a gap to open and a chance to grow larger. In this way large patches of pure Hall's totara form within beech zones in the Marlborough mountains. Although only small remnants remain, Hall's totara is thought to have been the main forest species in the 'beech gap' – a large area of central Canterbury and Westland where beech is absent – as well as other places where beech was restricted. It was once the dominant tree of Central Otago, doubtless owing to its tolerance of drought and cold.
Needle-leaved totara, Podocarpus acutifolius
Needle-leaved totara is an unusual species. It can form a low ground cover in beech forest but, when a beech falls, the totara can grow into a large shrub or a small, rounded tree, sometimes with a stout, twisted trunk. The bark is much like that of lowland totara in colour, though less grooved. When heavy snow falls, the rounded canopy may shatter and then other plant species regenerate. Vines such as lawyer (Rubus) often sprawl over the collapsed trees.
This tree usually grows in cold valleys and is allied to other species on frost flats, which are now rare ecosystems in New Zealand. Uncommon plants such as Pittosporum obcordatum and Melicytus flexuosus (a leafless whiteywood) may be associated with it, as in the Owen Valley of Murchison.
Needle-leaved totara is very common on gravel flood plains of Westland rivers, but overall it is the rarest of the four species, confined to an inhospitable habitat. Interestingly, it occurs on isolated serpentine outcrops in Nelson's mineral belt, which runs from the Bryant Range to D'Urville Island. This is a similar habitat to that occupied by P. gnidioides in New Caledonia (see below).
The tree is aptly named, as the short, sharp, densely clustered leaves of this species make the branches very prickly to handle. It has been regarded as a diminutive form of lowland totara, adapted for harsher conditions: according to New Zealand's expert on totara, Peter Wardle, 'The species may well be regarded as a derivative of P. totara which has retained a juvenile leaf form.' Indeed, the juveniles of both species are very similar in appearance.
Snow totara, Podocarpus nivalis
Snow totara is one of the gems of the New Zealand flora. At bushline (at around 1300 metres, but higher in the north and east and lower in the south and west), it forms a ground cover beneath stunted beech forest. Above the bushline, it forms spreading patches several metres across but sometimes just centimetres tall, the branches rooting as they grow. It is frequently associated with low shrubs of mountain toatoa (Phyllocladus alpinus) and sometimes other podocarps such as bog pine (Halocarpus bidwillii) and pygmy pine (Lepidothamnus laxifolius). It grows in the wet mountains scattered through North Island and along the South Island main divide, and in dry mountains to the east. In fact, it reaches its most spectacular development on the scree slopes that have originated since the beech forest was burnt hundreds of years ago. In these quite fertile places, with good underground moisture, snow totara can form pure expanses of interlocking or closely separate patches. An old plant declines in the centre, sometimes exposing a thick, twisted, dwarf trunk. It seems likely that individuals can be hundreds of years old.
Snow totara has the largest fruit of any totara species and at times produces large crops. Unlike other species, snow totara has probably expanded its range since the arrival of humans because new habitat (that is, the burned slopes) has been created and its rocky landscape is protected from fire.
South Westland totara, Podocarpus totara var. waihoensis
South Westland totara has long been identified as different from typical lowland totara and is formally diagnosed as a variety. It might equally be regarded as a variety of needle-leaved totara because it represents a hybrid between those two species. Structurally, it resembles a small (20-metre tall) version of lowland totara, with foliage shaped like that of needle-leaved totara but without the sharp point.
In this book, I recognise it as a separate species, Podocarpus 'waihoensis', tag-named in the modern convention for species names not yet formally published. In part, this is simply convenient, providing a less cumbersome name; but in other respects, it is a meaningful decision. First, it gives credit to the role of hybridisation in the origin of species, a process that is probably quite common in the New Zealand flora. Second, it gives prominence to habitat as a definitive character. This totara colonised the newly uncovered valley floors south of Hokitika after glacial retreat. This 'entity' was adapted to the finely textured glacial silt that formed the flood plains of South Westland, not the sandy or gravel plains to the north (which suited lowland totara), nor the cold inland valleys to the east (suiting needle-leaved totara). The fertile hybrid became a uniform population from Westland's Wanganui River in the north to the Hollyford in the south (the Hollyford being the southernmost Westland river with substantial valley floor habitat). Over the 20,000 years since the ice began to retreat, these trees have evolved novel chemistry to cope with their habitat. In fact, botanist Leonard Cockayne initially thought that the South Westland totara was a separate species, but in 1932 he opted for a hybrid origin and, consistent with the philosophy of the day, did not accord it formal taxonomic status.
TOTARA RELATIVES OVERSEAS
There are three, or perhaps four species that share so many characters with the New Zealand totara they are considered to be closely related and share a common ancestry, indicating that speciation occurred when the pieces of Gondwana were much closer together.
In the Errinundra National Park of Victoria, Australia, and also along a few rivers in northern Tasmania, there are small to medium-sized trees, with trunks nearly a metre in diameter, growing in a montane rainforest habitat. Their shape, bark and cones look remarkably like those of Hall's totara, although the foliage is much softer. Nearby, in the Snowy Mountains and southern Tasmanian mountains, there are prostrate patches of a similar species, almost identical to New Zealand's snow totara. These are called the mountain plum pine (Podocarpus lawrencei). Although both forms are classified as the same species, the habitats and growth form differ so greatly that I think they are distinct species, and that the high-altitude form has evolved from the forest species.
Another species, Podocarpus gnidioides – 'like a gnidia' – grows on New Caledonia, often regarded as a fragment of the ancient continent Zealandia. It forms thickets of small shrubs, sometimes spreading to form a patch, on elevated peaks and ridges. It is a member of the maquis, a type of shrubland growing on the soils derived from the underlying serpentine rock, which is often rich in minerals (e.g. nickel, magnesium and copper) and poor in nutrients (e.g. phosphorus and calcium). The leaves are distinctive in having rolled-down margins, an adaptation to extreme stress in a drought-prone and mineral-toxic habitat. The leaves of seedlings appear very much like those of New Zealand totara species, as do the male and female cones.
Excerpted from Totara by Philip Simpson. Copyright © 2017 Philip Simpson. Excerpted by permission of Auckland University Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
One: Totara in the natural world,
Two: How totara grows,
Three: Where totara lives and who lives with it,
Four: Te mauri o te totara: how Maori value totara,
Five: Nga mahi o te totara: using totara wood,
Six: Te kiri o Tane: the bark of totara,
Seven: Pakeha discover totara,
Eight: Totara creates a nation,
Nine: Where have all the totara gone?,
Ten: How totara is (and isn't) being protected,