A review of kowhai (Sophora spp.) and its potential for commercial forestry

Type of content
Journal Article
Thesis discipline
Degree name
Publisher
Scion
Journal Title
Journal ISSN
Volume Title
Language
Date
2021
Authors
Nguyen L
Bayne K
Altaner, Clemens
Abstract

jats:pBackground: Demand for imported sawn timbers in New Zealand has increased over the last decade, reflecting the lack of New Zealand-grown, naturally durable timber in the domestic market. Therefore, a market opportunity exists for sustainably grown, naturally durable timbers in New Zealand for specialty applications. Kowhai (Sophora spp.) are New Zealand native tree species, known for their bright, yellow flowers and reported to produce coloured, naturally durable heartwood.Methods: Information on kowhai was collated from literature, focusing on their potential for commercial forestry. The taxonomic relationships, species descriptions, establishment, and growth rates of kowhai were examined, along with timber properties and historical uses, as well as medicinal applications. The review identified potential market opportunities for kowhai and key areas for further research.Results: Kowhai refers to eight different Sophora species that are endemic to New Zealand. Kowhai is easily established and the different species hybridise readily. While growth and form of kowhai varies with species, site, and management, examples of straight single-stemmed trees and annual diameter increments exceeding 20 mm have been found. Kowhai timber properties might be comparable to those of teak (Tectona grandis L.f.). Kowhai contains alkaloids, a class of compounds used in pharmaceutical applications. The species have been used for timber and traditional medicine by Maori in the past, while European settlers used kowhai for their durable and flexible timber.Conclusions: Kowhai could be established as a sustainable, domestic source of high-quality timber and substitute imported specialty timbers in New Zealand on account of their natural durability, strength, stiffness, colour, and density properties. The residues could support a secondary industry, as a source of alkaloids for pharmaceutical applications or natural dyes. Key areas that require further study include growth rates and silviculture, mechanical timber properties, machining/processing characteristics, natural durability and cytisine levels in kowhai, as well as the cultural, economic, and ecological framework required for a commercial kowhai forestry industry. Lack of literature on, and expertise in the use of native timbers in general are barriers to promoting native species for commercial forestry in New Zealand.</jats:p>

Description
Citation
Nguyen L, Bayne K, Altaner C A review of kowhai (Sophora spp.) and its potential for commercial forestry. New Zealand Journal of Forestry Science (2021). 51:8
Keywords
heartwood, indigenous forestry, natural durability, native forestry, speciality timbers, timber properties
Ngā upoko tukutuku/Māori subject headings
Nga Upoko Tukutuku / Maori Subject Headings::Ohaoha | Economics::Ahumahi | Industries::Ahumahi ngahere | Ngāherehere; Ono rākau; Turaki; Forestry; Logging
ANZSRC fields of research
0501 Ecological Applications
0705 Forestry Sciences
Fields of Research::30 - Agricultural, veterinary and food sciences::3007 - Forestry sciences::300701 - Agroforestry
Fields of Research::30 - Agricultural, veterinary and food sciences::3007 - Forestry sciences::300708 - Forestry product quality assessment
Fields of Research::45 - Indigenous studies::4509 - Ngā mātauranga taiao o te Māori (Māori environmental knowledges)::450901 - Te ahuwhenua me ngā mahi ngahere o te Māori (Māori agriculture and forestry)
Rights
© The Author(s). 2021 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.