Distributed on the two main islands of New Zealand where it is a co-dominant or canopy emergent tree in montane-subalpine evergreen rainforests. it is slow growing and very long lived and sensitive to forest fires.
Description
A very long lived tree from the mosit montane forests of New Zealand
Distribution
Endemic to both North and South Islands. In the North from Te Moehau, Te Aroha and Mt Pirongia south.
The distribution of this species on the two main islands of New Zealand is divided in disjunct stands in isolated mountains, as well as more or less contiguous in some areas. This is partly the natural situation, and partly the result of historical deforestation
Habitat and Ecology
Libocedrus bidwillii is a co-dominant or canopy emergent tree in montane-subalpine evergreen rainforests of the mixed angiosperm-conifer class, growing together with the podocarps Dacrydium cupressinum (at lower altitudes), Halocarpus biformis, Phyllocladus trichomanoides var. alpinus, and Podocarpus cunninghamii. Frequent angiosperm trees are Metrosideros umbellata, Nothofagus solandri, Quintinia acutifolia and Weinmannia racemosa.
Libocedrus bidwillii is a good example of a long-lived conifer (max. 800-1,000 years) dependent for regeneration on stand-replacing episodal disturbances such as volcanic eruptions and windthrow in extreme weather. The altitudinal range is from 250 m to 1,370 m a.s.l. The soil in these forests has a high organic content and is usually saturated with water. In many places at higher altitudes the forest is confined to drainage systems, surrounded by peaty moorland dominated by tussock-forming sedges. The climate is superhumid, with high rainfall and frequent fog, summers are short and cool.
Human Uses
The reddish wood of this species is not very valuable for timber as it splits easily. As an ornamental tree it has been planted more often than Libocedrus plumosa, the lowland species of New Zealand, but it remains restricted to arboreta and other tree collections in large gardens.
Conservation Status
Global Status
Near Threatened
Global Rationale
The area of occupancy (AOO) based on a comprehensive distribution map incorporating specimen data of all three major New Zealand herbaria, is estimated to be 1,325 km2 which is within the threshold for Vulnerable. There has certainly been historical reduction but this hasnot been quantified. The reduction has now ceased due to legislation that protects native forest stands. The species is slow growing and very long lived, and sensitive to forest fires. Near Threatened seems therefore the most reasonable category as it almost qualifies as threatened under criterion B2ab(v).
National Status
Not Threatened
Conservation Actions
Nearly all remaining natural 'old-growth' stands are now protected. Many of these occur in montane forests and are presumably of similar extent as before European settlement