- Title
- Testing alternative Pinus species and hybrids for the South African structural pole market
- Creator
- Ndovela, Lisakhanya Sizo
- Subject
- Gqeberha (South Africa)
- Subject
- Eastern Cape (South Africa)
- Subject
- South Africa
- Date Issued
- 2021-04
- Date
- 2021-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/52002
- Identifier
- vital:43435
- Description
- According to the South African National Standards, only Pinus canariensis, Pinus pinaster and Pinus radiata are suitable to be used as structural softwood poles. Of the three Pinus species mentioned, only P. radiata is still planted in South Africa and its future and availability is uncertain. The lack of availability of structural pine poles necessitates the South African forestry industry to look at alternative softwood species to plant. The broad aim of this study was to determine whether there are alternative Pinus species or hybrids that can be planted in South Africa’s Western and Southern Cape areas that will have suitable properties to be used as a resource for structural poles. This document reports on the testing of the strength and stiffness, as well as other relevant properties, of poles from several Pinus species and Pinus hybrids. The poles were derived from thinned eight-year-old tree stands in Knysna, Western Cape. Poles were peeled, kiln dried and graded before bending tests were carried out. Species and hybrids were also assessed for differences within a tree along the length. Also, the correlation between modulus of rupture (MOR), modulus of elasticity (MOE) and wood grading properties was evaluated. The results showed that there was a highly significant effect of species and log position on the mean MOR of the poles. In general, poles from the bottom of the tree had a higher mean MOR than poles from the top of the tree. There was also a highly significant effect of species and pole position on the mean MOE of poles, with poles at the top of the trees generally having higher MOE values. A very concerning finding was that the 5th percentile MOR and mean MOE values of all the species were far lower than required by SANS 10163-1 (2003). Even for the best performing species, P. radiata, the MOR 5th percentile value was less than half the required value, while the mean MOE was also 39% lower than the required mean MOE. Apart from P. radiata, the P. maximinoi performed the best of all species and hybrids since it had a statistically similar mean MOR and MOE to P. radiata. P. elliottii and the hybrid P. elliottii x caribaea had statistically significant lower MOR and MOE than P. radiata.
- Description
- Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2021
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (viii, 50 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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