Browsing by Author "Lambrechts, Hugo Amos"

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    The potential of Eucalyptus hybrids in farm forestry in the semi-arid winter rainfall region of South Africa
    (Stellenbosch : Stellenbosch University, 2018-12) Lambrechts, Hugo Amos; Du Toit, Ben; Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science.
    ENGLISH ABSTRACT: The aim of this study was to investigate Eucalyptus hybrids as a source of woody biomass in the semi-arid winter rainfall region of South Africa. The study focuses on an experimental planting at 10 years of age and the coppice crop from this experiment grown for nine months after clear felling. The trial investigated the survival, potential production (growth) and coppicability of several Eucalyptus hybrids, namely E. grandis x camaldulensis, E. grandis x resinifera, E. grandis x tereticornis and E. saligna x urophylla, which were compared to the control of E. cladocalyx and commercial controls of E. dunnii and E. grandis x camaldulensis. The survival and potential production were explored on a taxa and provenance, genotype and stand level, while the coppice results were ranked on a genotype level. Overall, the survival on the site was above 75 %, excluding the controls of E. cladocalyx and E. dunnii, which did not perform well. At 10 years of age, the experimental stand achieved a mean annual increment (MAI) of 17.24 m3.ha-1.a-1. Basal area growth was used to rank the growth response of the tested genotypes. The basal area was upscaled from single tree plots which meant that the mean value yielded a useful estimate, however, the upscaled value of individual genotypes from the single tree plots were only reliable to rank genotypes and not to estimate growth potential in field. The upscaled basal area ranged between 12 m2.ha-1 and 55 m2.ha-1. Several of the tested hybrids were well suited to the semi-arid site, namely: E. gxc Albacutya CSS01659 (9), E. gxc Albacutya CSS01682 (13), E. gxt (AUS) seed SR0046xT32 (84) and E. gxt (AUS) seed AG049xT08 (83) and E. gxc (SA) seed SGR1231xC42 (76). Slightly less than 50% of the genotypes had good coppicability. The biomass produced in coppice shoots was not significantly different among the taxa at nine months of age. The potential for deploying the newly tested genotypes in farm forestry projects in semi-arid climates of the Western Cape is discussed