Variation in the wood properties of coast redwood trees in New Zealand

Abstract

Background: There is wide variation in the wood properties of plantation-grown coast redwood (Sequoia sempervirens (D.Don) Endl.) in New Zealand. Contributing factors are the seed source, silviculture, growth rate and age of the trees in the plantation forests. Little is known about how these factors affect the variation of wood properties among and within the trees of New Zealand's coast redwood forests. Methods: The wood of plantation-grown coast redwood trees from three forests in the North Island, New Zealand, was evaluated using butt log and breast height discs and cores, and in vitro decay tests with brown-and white-rot fungal cultures, to determine the variation in the heartwood content, basic density, and red colour and natural durability of the heartwood.

The chemistry and bioactivity of various heartwood extracts from redwood (Sequoia sempervirens) against two species of fungi

“…These samples contained wood from old-growth trees and second-growth trees. Their findings were consistent with the large variability in natural durability reported for plantation-grown redwood from New Zealand (Jones et al 2011(Jones et al , 2014. Heartwood durability according to Standard EN350-1 (CEN 1994) varied from 'notdurable' to 'very-durable' , with the majority of samples being 'durable' or 'very-durable'.…”

“…Natural durability significantly increased from pith to bark and slightly from bottom to top in the heartwood of the stem. These radial and axial gradients in natural durability were confirmed for oldgrowth and second-growth trees (<100 years) (Clark and Scheffer 1983), and are consistent with the data reported for plantation-grown redwood from New Zealand (Jones et al 2011(Jones et al , 2014. Gradients in natural durability have also been observed in other species (Taylor et al 2002) and highlight the general inferior wood quality of corewood, the wood formed by cambium of young age (Burdon et al 2004).…”

Financial Comparison of Afforestation Using Redwood and Radiata Pine within New Zealand for Regimes That Derive Value from Timber and Carbon

“…Redwood coarse woody debris has been found to have very high decay resistance, which, when expressed as a half-life, ranges from 27 to 35 years for material in primary forests [62], greatly exceeding the documented half-life of 4-14 years for radiata pine [63]. Further research is required to determine the half-life of coarse woody debris in redwood plantations, which due to reduced heartwood is likely to be lower than the estimate for primary forests but significantly higher than that of radiata pine [64]. As redwood rapidly coppices from the cut stem, and these sprouts form the next crop, it is likely that a large part of the root system remains alive to support coppice growth.…”

Adverse Genetic Correlations and Impacts of Silviculture Involving Wood Properties: Analysis of Issues for Radiata Pine

“…In the Cupressaceae/Taxodiaceae complex, including cypresses and coast redwood (Sequoia sempervirens D.Don Endl. ), in which durable heartwood is desirable, young trees often have disappointing heartwood durability [110,111]. Outside conifers, this has also been observed in several eucalypt species [112], and evidently in teak (Tectona grandis L. f.) [113].…”