Dacrydium cupressinum

Scientific name: Dacrydium cupressinum Solander ex J.G.Forster 1786

Synonyms: Dacrydium cupressiforme Carrière, Thalamia cupressina (Sol. ex G.Forst.) Spreng.

Common names: Red pine, Rimu

Description

Tree to 35(-60) m tall, with trunk to 1.5(-2.5) m in diameter, sometimes free of branches for 20 m or more. Bark smooth, brown, warty with rows of tiny lenticels, weathering gray and flaking off in irregular, generally elongate scales. Crown narrowly conical and weeping in youth, becoming egg-shaped to spherical with age, rather shallow in dense stands, with horizontal to upwardly angled branches bearing numerous drooping branchlets densely clothed with and largely hidden by foliage. Transition between juvenile and adult foliage gradual. Juvenile leaves on long, sparsely branched, hanging branchlets, 4-7(-9) mm long. Adult leaves scalelike, narrowly triangular, loosely overlapping, sticking out from the twig at a forward angle, slightly incurved at the prickly tip, 2-3(-4) mm long, 0.5-0.8(-1) mm wide, a little wider than thick, triangular in cross section. Midrib with a sharp keel beneath and scarcely raised above. Cones often borne on young trees with foliage transitional between juvenile and adult leaves as well as on mature trees with adult foliage. Pollen cones appearing thicker than their stalks and accompanying leafy bracts, (5-)8-15 mm long, 4-6 mm in diameter. Pollen scales triangular, with a conspicuous, prolonged, needlelike green tip 0.5-1.5 mm long. Seed cones on a very short branchlets with reduced leaves 1-1.5 mm long. Free tips of the bracts making up the podocarpium resembling the foliage leaves but shorter, about as long as the leaves of the supporting branchlets, 1-1.5 mm long, barely overlapping the base of the epimatium. Mature podocarpium red, with one fertile bract. Epimatium cuplike, 3-4 mm deep. Seed deep bluish black, egg-shaped, (4-)6-8 mm long, 3-4 mm thick, with a broad, dimples beak less than 1 mm long.

Widely distributed throughout the three main islands of New Zealand, mostly within 50 km of the coast on South Islands but well distributed within the interior of North Island. Forming small pure stands or scattered as a dominant or codominant in or above the canopy of temperate lowland and montane rain forests and reaching the subalpine zone on Stewart Islands; 0-750(-950) m.

Conservation Status

Red List Category & Criteria: Least Concern

This species, and its main forest type, has undergone a significant decline over the last several centuries. However, the majority of this decline pre-dates the period of this assessment. In the absence of any current or ongoing decline an assessment of Least Concern is the most appropriate. Logging and forest clearing have reduced the population historically, these activities have now ceased. Due to changes in land use which are permanent, the population became fragmented, although not severely fragmented in an IUCN sense. Regeneration is causing the population to increase again. Dacrydium cupressinum is a dominant or codominant emergent in mixed conifer (podocarp) forest or conifer-angiosperm forest at low to middle elevations up to 700 m a.s.l. These forests are (warm) temperate evergreen rain forests with year-round high precipitation and are multi-layered with emergent conifers, a canopy of conifers and/or angiosperms, an understorey of shrubs, tree ferns and palms, and a ground cover of ferns and mosses. In the kauri forest of Northland Dacrydium cupressinum is a minor component, but in other forest types it is often the most common species, sometimes occurring in nearly pure stands. Very large specimens may be around 1,000 years old, but few of these survive today in only remnants of a once extensive native lowland forest cover. Common associated conifer species are Agathis australis (restricted to the northern part of the range of Dacrydium cupressinum), Podocarpus totara, Prumnopitys ferruginea, Prumnopitys taxifolia, Dacrycarpus dacrydioides, Manoao colensoi, Phyllocladus trichomanoides and, less frequently, Halocarpus kirkii. Some common angiosperm trees are Beilschmiedia tarairi (Lauraceae), Metrosideros spp. (Myrtaceae), Weinmannia racemosa (Cunoniaceae) and Quintinia acutifolia (Escalloniaceae), and there are many other genera and species. Dacrydium cupressinum is a typical example of a long-lived 'catastrophic regeneration' conifer (Ogden and Stewart in Enright and Hill 1995). Historical logging and the conversion of forests for agriculture have reduced the total population and probably its area of occupancy. These threats have virtually ceased. Current threats include introduced species such as possums and deer. Rimu or Red pine was, when exploited, the major timber tree in New Zealand as it was ubiquitous throughout the lowlands of the major islands and attained large sizes. The wood is reddish brown in colour, often finely figured and very durable and strong. It was used in general construction, for bridges, railway sleepers, fence posts, indoor flooring and panelling, and furniture. The most decoratively figured pieces were reserved for cabinet making. Due to severe depletion of this natural resource, exploitation has been halted and this species is now protected from logging by law. As a slow growing tree it is not considered suitable for plantation forestry and it finds only limited use as an amenity tree in gardens and parks, mainly in New Zealand. As a native tree this species is now protected from logging under the laws of New Zealand. Several populations occur within protected areas, others are on private land. The distribution of protected forest areas more or less covers the extent of occurrence as formerly occupied by this species. Natural regeneration is good where mature trees occur and is also complemented by re-vegetation initiatives. These measures will lead in future to an increase in area of occupancy and/or abundance.

References

Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland

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