Southern African Forestry Journal - latest Issue
Volume 2006, Issue 208, 2006
Author Charlie M. ShackletonSource: Southern African Forestry Journal 2006, pp 1 –4 (2006)More Less
Extracted from text ... Southern African Forestry Journal - No. 208, November 2006 1 Guest Editorial Urban forestry - A cinderella science in South Africa? INTRODUCTION The benefits of forests (in their broadest sense) and of trees to the natural environment and rural communities are well known throughout the world, including in South Africa (e.g. see chapters in Lawes et al. 2004). The presence of these benefits has also been extrapolated to urban situations, where natural forests and veld might be left in situ, or trees planted in public spaces, or in private gardens. These benefits span the social, aesthetic, health, environmental and economic ..
A comparison of different planting methods, including hydrogels, and their effect on eucalypt survival and initial growth in South Africa : scientific paperSource: Southern African Forestry Journal 2006, pp 5 –13 (2006)More Less
Research to minimize mortality and enhance early growth during the re-establishment of eucalypts includes the use of optimum growing stock and planting techniques, the application of adequate volumes of water at planting (where appropriate), correct fertilizer application and placement, and optimum environmental conditions at planting. The use of hydrogels at planting, Stockosorb<sup>(R)</sup> 400K in particular, has also shown improvements in seedling survival and initial growth when planted under adverse conditions. The reformulation of this hydrogel through the addition of plant nutrients (Aquasoil<sup>TM</sup>) was marketed to enhance initial growth whilst retaining the inherent benefits of the hydrogel component. Whether Aquasoil<sup>TM</sup> could replace the use of a granular fertilizer thus needed to be tested. Three field trials were implemented covering a range of soils, climates and eucalypt species to compare the effect of Aquasoil<sup>TM</sup> together with various planting practices, including those of planting with, or without water, or Stockosorb<sup>(R)</sup> 400K (water and Stockosorb<sup>(R)</sup> 400K treatments were also tested with or without the application of a granular fertilizer) on eucalypt survival and initial growth. Results from these trials indicated that: i) planting without water generally resulted in poorer survival and growth, ii) although planting with water improved survival, growth was inconsistent and not always the best, iii) the application of a hydrogel (Stockosorb<sup>(R)</sup> 400K) consistently increased seedling survival and initial growth during sub-optimal planting conditions, iv) the surface application of granular fertilizer (whether used in combination with water or a hydrogel) at planting produced the fastest and largest growth responses of all treatments, and v) the use of Aquasoil<sup>TM</sup> (hydrogel combined with nutrients) to significantly improve survival and initial growth produced inconsistent results when compared to the application of a hydrogel only (no additional nutrients added).
Phenotypic variation in fruit, seed and seedling traits of nine Uapaca kirkiana provenances found in Malawi : scientific paperSource: Southern African Forestry Journal 2006, pp 15 –21 (2006)More Less
<i>Uapaca kirkiana</i> is one of the priority indigenous fruit tree species for domestication in southern Africa. Natural populations of <i>U. kirkiana</i> are declining due to deforestation, forest fragmentation and wildfires. Knowledge of genetic variation is prerequisite for development of conservation strategies. A provenance evaluation study was conducted at Bunda College of Agriculture in Lilongwe, central Malawi to determine the variability in fruit, seed and seedling characteristics of nine populations found in the southern, central and northern regions of Malawi. Results showed significant differences (P<u>< </u> 0.05) between provenances in fruit weight, seed weight, seed length and seed width. The central Malawi provenances of Dzalanyama and Chimaliro had the heaviest mean weight of fruits of 23.9g and 23.8 g respectively, the lightest fruits (14.6g) were found in Namoni Katengeza provenance. There were no significant differences (P <u><</u>0.05) in number of seeds per fruit within and between provenances. The provenances differed significantly in cumulative germination percentage, ranging from 26% for Tsamba provenance in southern Malawi to 87% for Dzalanyama provenance in central Malawi. There was a consistent regional variation in stem collar diameter and height growth with central Malawi (Dzalanyama and Chimaliro) and northern Malawi provenances having taller seedlings ranging from 5.2 to 9.0 cm, with the exception of Namoni Katengeza provenance in central Malawi. The root collar diameters were significantly higher for Dzalanyama and Chimaliro (2.5 to 3.9 cm) than southern Malawi provenances whose seedling collar diameter averaged 2.3 centimetres. The nursery provenance trial has shown existence of considerable variation in seed germination, fruit and seed traits in <i>U. kirkiana.</i> Seed and seedling growth traits may prove to be important criteria for selection of provenances for domestication to provide farmers with sustained fruit production for consumption and economic benefits.
Nutrient cycling by Acacia erioloba (syn. Acacia giraffae) in smallholder agroforestry practices of a semi-arid environment in the North West Province, South Africa : scientific paperSource: Southern African Forestry Journal 2006, pp 23 –30 (2006)More Less
<i>Acacia erioloba</i> is an ecologically important indigenous leguminous tree in semi-arid areas of Southern Africa because of the many benefits it offers to local communities. However, little quantitative plant and soil data exist to explain its ability to enhance soil fertility under local conditions. Paired soil samples taken under and beyond <i>A. erioloba</i> tree canopies were analyzed to quantify the concentration of nutrients in two local agroforestry practices defined as trees dispersed on cultivated and grazing lands. In both practices, there was a significantly higher (p<0.05) concentration of N, P, Ca, Mg, Zn and Mn in soils collected from under <i>A. erioloba</i> canopies compared with those collected beyond the canopies. The nutrient concentrations were consistently higher in soil from trees that were located in grazing land than croplands. An assay of soil nutrient availability was done using wheat as a bioassay plant in pots and showed that plant height, dry matter yields and the concentrations of N, P, Ca, Mg, and Zn in the tissues of wheat were related to soil nutrient concentrations. This was confirmed by the significant correlation coefficients between soil and plant tissue nutrients. A combination of leaf-fall, continuous presence of domestic livestock near the trees and increased soil moisture were considered to have contributed to the enhanced plant nutrient concentration, plant growth and dry matter yields of wheat grown in soil from underneath the canopies of <i>A. erioloba</i> trees. The perspective that a local indigenous tree can contribute to improved fertility of soils in both cultivated and grazing lands is valuable as it can be used to increase the productivity of crops and grass for grazing animals in smallholder agricultural systems. It is recommended that the integration of <i>A. erioloba</i> in existing farming systems should be intensified in order to enhance sustainability.
In vitro shoot multiplication and rooting from seedling explants of Pterocarpus angolensis in Zambia : scientific paperSource: Southern African Forestry Journal 2006, pp 31 –37 (2006)More Less
<i>Pterocarpus angolensis</i> is a savanna tree species growing mostly in the southern part of Africa. Exploitation for its medicinal and commercial uses has led to diminishing of wild populations. Developing reliable <i>in vitro</i> protocols for propagation would enable mass production of desired genotypes for domestication and conservation of <i>P. angolensis.</i> In this study, the effect of 6-benzylaminopurine (BAP), isopentenyl-adenine (2-iP) and thidiazuron (TDZ) were tested for shoot induction on cuttings from four weeks old <i>P. angolensis</i> seedlings. BAP at 5 mg/l gave higher shoot multiplication compared with 0 - 2 mg/l BAP. Although axillary buds opened on cuttings treated with 0.1 to 2 mg/l TDZ, no elongation occurred. Shoots placed on 0.5 - 5 mg/l 2-iP produced roots but no axillary shoots. Indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) were tested for ability to induce rooting of micropropagated shoots. IAA at 1 mg/l and IBA at 1 - 4 mg/l induced higher percent rooting than other auxin concentrations. Shoots on media lacking auxins also rooted well (48%), suggesting that no growth regulator was required for rooting of 4 weeks old <i>P. angolensis</i> shoots.
The wood properties and sawn-board quality of South African-grown Pinus maximinoi (HE Moore) : research noteAuthor F.S. MalanSource: Southern African Forestry Journal 2006, pp 39 –47 (2006)More Less
This report summarises results of past research in South Africa on the wood properties and qualities of <i>P. maximinoi, </i> supplemented by results of a study performed recently on an approximately 15.5-year-old provenance trial at Wilgeboom after it had been severely damaged by fire. The trees selected to study wood density, branching characteristics and sawn-board quality of the species, were previously selected for further breeding for their superior volume growth and stem form. Differences in mean internodal length and mean branch diameter were statistically highly significant among provenances, on average being longer and generally thicker than those of the <i>P. elliottii</i> and <i>P. patula.</i> The bark-layer of <i>P. maximinoi</i> was thicker than that of <i>P. patula</i> but it differed little in thickness with that of <i>P. elliottii.</i> Provenance means in air-dry wood density varied within a relatively narrow band of 0.457 to 0.483 g/cm3, with an average mature wood density resembling closely that of <i>P. patula.</i> However, <i>P. maximimoi</i> was characterised by increased uniformity in density across its radius, as it tended to form denser wood in the central parts of its stem, causing its pith-to-bark density gradient to be flatter. Growth rate had no effect on wood density, but improved radial density uniformity was clearly associated with increased growth rate. Sawn boards were of good quality and showed little warp after drying despite the fact that some of the trees were slightly crooked, with possibly a higher incidence of compression wood. Compared to <i>P. patula</i> and <i>P. elliottii</i> this species exhibited a darker brown colour with almost a reddish tinge when freshly cut. The annual rings were hardly recognisable on rough-sawn surfaces. Wandering pith often occurred in some boards as a result of the higher degree of stem crookedness. Since the branches of <i>P. maximinoi</i> tend to be arranged in whorls, it can be expected that the impact of knots on the strength of the sawn boards would predominantly be the result of the combined effect of knots grouped together, rather than individual knots. This is also a valuable attribute, as the species lends itself to the production of relatively long knot-free board sections from the unpruned parts of the stem, which would enable manufacturers of finger-jointed products to increase the volumes and diversity of their products, especially where appearance is important. Loose knots occurred more frequently in boards cut from <i>P. maximinoi</i> compared to the two controls, most likely as a result of pruning that was carried out too late considering the fast growth of the species.
Author S.J. TruemanSource: Southern African Forestry Journal 2006, pp 49 –52 (2006)More Less
Clonal forestry is the approach used for deployment of <i>Pinus elliottii</i> x <i>P. caribaea</i> hybrids in Queensland, Australia. Clonal forestry relies on the ability to maintain juvenility of stock plants while selections are made in field tests, so that genetic gains are not eroded by the effects of stock plant maturation. Two parallel approaches are employed in Queensland to maintain juvenility of clonal material. Firstly, the ortet and several ramets of each clone are maintained as archive hedges <20-cm height for the duration of field tests. Secondly, shoots from archive hedges are stored in tissue culture at low temperature and low irradiance to slow growth and slow maturation. Once the best clones have been identified, production hedges are derived from both archive hedges and tissue culture shoots. About 6 million rooted cuttings are produced annually, representing almost the entire planting program of <i>Pinus</i> in subtropical Queensland.
Growth performance of lesser-known Leucaena species / provenances at Gairo inland plateau, Morogoro, Tanzania : research noteSource: Southern African Forestry Journal 2006, pp 53 –62 (2006)More Less
Growth performance and psyllid resistance was studied among nineteen lesser- known <i>Leucaena</i> species/ provenances at Gairo inland plateau, Morogoro, Tanzania. Assessment was done at irregular intervals for survival, root collar diameter and diameter at 30 cm above the ground, height, diameter at breast height, multiple stems production, biomass and psyllid resistance. Final assessment of these tree attributes was done at 37 months after planting, while psyllid resistance was assessed at 9 and 37 months after planting. During the final assessment occasion, height ranged from 2.69 m for <i>L. collinsii</i> Ex. Chiapas to 4.87 m for <i>L. diversifolia</i> Ex. Veracruz. Diameter at breast height (Dbh) ranged from 2.26 cm for <i>L. shannonnii</i> Ex. Chiapas to 4.93 cm for <i>L. diversifolia</i> Ex.Veracruz, while multiple stems production ranged from 2709 stems ha<sup>-1</sup> for <i>L. pulverulenta</i> Ex. Tamaulipas to 7135 stems ha<sup>-1</sup> for <i>L. leucocephala</i> Ex. Morogoro and untransformed survival ranged from 43.75% for <i>L. pulverulenta</i> Ex. Tamaulipas to 100% for <i>L. diversifolia</i> Ex. Veracruz. Total wood biomass production ranged from 3.74 t/ha for <i>L. shannonnii</i> Ex. Chiapas to 15.61 t/ha for <i>L. diversifolia</i> Ex. Veracruz. The study has shown that species/ provenances differ significantly in survival, diameter, height growth, psyllid resistance, multiple stem production and biomass production. Based on these findings, provenances <i>L. diversifolia</i> Batch (15551), <i>L. diversifolia</i> Ex. Mexico, <i>L. diversifolia</i> Ex. Veracruz and <i>L. pallida</i> Ex. Oaxaca are recommended for Gairo and similar sites.
Technical and institutional capacity in local organisations to manage decentralised forest resources in Uganda : management paperSource: Southern African Forestry Journal 2006, pp 63 –78 (2006)More Less
Uganda is one of the sub-Saharan African countries that has devolved the management of forest resources. Meaningful devolution, however, requires that local governments and other community organizations should have capacity in terms of adequate and competent human resources, finance, information, skills, and the appropriate legal framework to effectively deliver services. This paper examines the technical and institutional capacity in selected local organisations to manage decentralised forest resources in Uganda. We found that technical and institutional capacity to implement decentralised forest governance exists in local organisations through partnerships with other actors in the productive use of the available resources. Local organisations mobilised and managed human, physical and financial resources for decentralised forest management. They also demonstrated the capacity to make and implement integrated plans and budgets and formulated byelaws regulating forest use. Our findings, however, revealed that none of the organisations had either the legal mandate or sufficient human and physical resources to govern forest resources unilaterally due to inadequate devolution of decision-making powers and inadequate fiscal support from the central government. The findings suggest a need for local organisations to recruit more technical staff, strengthen internal sources of revenue and networking amongst organisations both at local and national government levels for effective management of decentralised forest resources.
Author W.J.A. LouwSource: Southern African Forestry Journal 2006, pp 79 –88 (2006)More Less
The reason for the survival and growth of the Forestry Industry is its ability to adapt to change. The Industry has a proven record of innovation and entrepreneurial ability to meet the challenges of the future. Taking into account the renewable character of forestry and the current positive initiatives and developments, the future looks a great deal better than five years ago. Two of the major events during this period were the growth in processing capacity and the change in the attitude of the Department of Water Affairs and Forestry (DWAF) towards Industrial/Commercial forestry. These and other main events in the general history of the forest industry are presented in this paper under: forest law and policy, privatisation of State forests, afforestation, economics, outsourcing, protection, environmental matters, research, education and training and professionalism.
Source: Southern African Forestry Journal 2006, pp 89 –92 (2006)More Less
Extracted from text ... Southern African Forestry Journal - No. 208, November 2006 89 SAFJ Index 2006 SA FORESTRY JOURNALS INDEX: No 206, No 207, No 208 Note: This is an Abbreviated Index. Paper title shown under name of main author only. 205/25(10pp) means - Journal No 205 Page 25 Pages 10 'et al' means - More than a single author Author Title Journal Email Ackerman P A 207/55 Adams P 207/63 Banana A Y 208/63 Banasiak M 206/13 Beck S L 207/21 Bjornstad A 208/15 Bokosi J M 208/15 Boreham G R A survey of cossid moth attack in Eucalyptus nitens on the ..