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- Volume 2004, Issue 200, 2004
Southern African Forestry Journal - Volume 2004, Issue 200, 2004
Volume 2004, Issue 200, 2004
Author Dennis OwenSource: Southern African Forestry Journal 2004, pp 1 –4 (2004)More Less
Extracted from text ... _ Editorial Southern African Forestry Journal What has been achieved since October 1938? In this 200th edition of the SAFJ I believe it is appropriate to look back and try to assess what the voluntary efforts by so many might have achieved, since No 1 appeared in October 1938. In SAFJ No193 a short history of the Journal appeared (Owen, 2002). Further research has brought to light a name change that was not mentioned then, and that is that in June 1962 (No.41) the name changed from "The Journal of the SA Forestry Association" to the "South African ..
Early selection of Eucalyptus clones in retrospective nursery test using growth, morphological and dry matter criteria, in Republic of Congo : scientific paperSource: Southern African Forestry Journal 2004, pp 5 –17 (2004)More Less
Within the framework of the eucalyptus breeding programme in the Congo, two retrospective tests were conducted using mature clones in the field and young cuttings under nursery conditions with two hybrids: 13 clones of <I>Eucalyptus tereticornis Eucalyptus grandis</I> for the test TC 82-1B and 17 clones of <I>Eucalyptus urophylla Eucalyptus grandis</I> for the test TC 86-10. Growth, morphological and biomass traits were measured during the nursery phase and growth traits were measured in the field trials. Analysis of variance showed that the clones were significantly different for most of the traits at the two stages. However, for the clonal test TC 82-1B, all the coefficients of correlation between juvenile and mature traits were very low (around 0, 3) and not significantly different from zero. For the clonal test TC86-10, several coefficients were significantly different from zero but their value was small, around 0, 5. This weak correlation was explained by the weak control of growth by genes at the young cutting stage, the morphology of cuttings, the non-optimal testing conditions, the high clone by environment interaction and the reduced genetic base of the clonal population. For clonal test TC86-10, multitrait selection, using the association of total growth and growth increment or biomass traits increases the coefficient of determination. These initial results show that early selection of <I>Eucalyptus</I> clones could be used to reject of around 30% of the poorer growing clones at the mature stage.
Survival and growth of Pinus patula at two years in response to harvest residue and pest management, in Mpumalanga, South Africa : scientific paperSource: Southern African Forestry Journal 2004, pp 19 –26 (2004)More Less
Previous research has indicated that the presence of harvesting residues, post-planting temperature and rainfall, and insect pests and diseases, are among the main causes of mortality during re-establishment of <I>Pinus patula</I> stands. The main objectives of this work were to confirm previous observations on the effects of these factors on initial survival and growth of <I>P. patula</I> seedlings. Three harvest residue management treatments (burning, harvesting residues left <I>in situ</I> or removed) and four pest management treatments applied at planting (fungicide, insecticide, fungicide and insecticide, and a control, where no pesticides were used) were tested in combination with each other. For the first two years after planting, there was a significant effect of harvest residue and pest management on survival. At two years, survival in the burned treatment was 59 %, possibly due to the presence of <I>Rhizina undulata</I>. Where the harvest residues were not burned, the survival was 88 %. Application of a fungicide and insecticide at planting improved survival in all harvest residue treatments, especially the burned treatment. Tree growth was the best where both a fungicide and insecticide had been applied at planting, followed by the individual application of either a fungicide or insecticide, with the poorest growth occurring in the control treatment.
Effects of temperature on Pinus patula seedlings growing in pots in a controlled environment : scientific paperSource: Southern African Forestry Journal 2004, pp 27 –38 (2004)More Less
The re-establishment of Pinus patula seedlings into sites with high harvesting residue (slash) loads can negatively affect the survival of these plants. Field trials have examined the role that insect pests and fungal diseases play in causing this phenomenon. Research has also indicated that temperatures at ground level tend to be higher in the slash during the day, compared to areas where slash had been removed. The current investigation aimed to determine whether the high temperatures experienced in the slash are likely to be the sole causal agent for the observed mortality. Pots containing P. patula seedlings were exposed to four different temperatures (26<sup>o</sup>, 32<sup>o</sup>, 38<sup>o</sup> and 44<sup>o</sup> C) in an illuminated growth chamber. The duration of exposure was 1, 2 or 3 hours. The exposure to the different temperatures was repeated on 7 days in a 10 day period. Respiration rates increased significantly at the high temperatures, while the chlorophyll a, b and total chlorophyll concentrations were significantly reduced at the highest temperature. Increasing temperature also significantly reduced both height and new root growth in the seedlings during the experiment. The results indicate that, although no mortality was observed during the experiment, continued exposure to high temperatures over an extended period has the potential to cause seedling mortality. However, it is hypothesised that high temperatures predispose the seedlings to attack by pests and pathogens on site.
Comparative growth performance of different Casuarina species and provenance at Lushoto in the West Usambara mountains, Tanzania : scientific paperSource: Southern African Forestry Journal 2004, pp 39 –49 (2004)More Less
Variation in growth charactristics, coppicing ability and understory vegetation development was assessed in four Casuarina species (<I>C. equisetifolia, C. junghuhniana, C. cunnighamiana and C. oligodon</I>) grown in Lushoto in the West Usambara Mountains (WUM), Tanzania. The performance of the four species as well as of 12 provenances, including 5 landraces within some of the species was studied. Tree survival was assessed at 36 months; stem height, diameter at breast height (dbh), volume, biomass, coppicing ability and understorey vegetation development were assessed at 78 months. Survival was significantly lower in <I>C. equisetifolia</I> (79%) than in other species (>97%). There were significant differences in growth between species, with <I>C. junghuhniana</I> and <I>C. oligodon</I> outperforming the others, and <I>C. cunnighamiana</I> outyielding <I>C. equisetifolia</I>. Only <I>C. junghuhniana</I> and <I>C. cunnighamiana</I> coppiced, while understorey biomass was significantly higher under <I>C. equisetifolia</I> than under <I>C. oligodon</I>. There were significant differences in growth between provenances within species, with growth of new provenances often exceeding that of the local land races. The potential for fuel wood production and soil N - enrichment through foliage addition also exhibited inter-specific and intra-specific variation. There is great opportunity to significantly improve the productivity, and at the same time broaden the genetic base of <I>Casuarinas</I> through species and provenance selection for planting in the highland areas of the WUM. However, while exploiting the productive potential of <I>Casuarinas</I>, there is need to build sufficient information regarding their side effects on conservation of natural ecosystems, and local community's views on how to minimise the problem.
The effect of applying prophylactic measures on the post-planting survival of Pinus patula in South Africa : scientific paperSource: Southern African Forestry Journal 2004, pp 51 –58 (2004)More Less
The observed survival of <I>Pinus patula</I> seedlings and cuttings has, on many occasions, been inadequate in nurseries and after field planting in South Africa. There have however, been several reports that survival can be improved if a fungicide is applied at planting, indicating that mortality is partially related to pathogenic activity. This paper summarises the results from two trials established to investigate the effects of the fungicide, Benlate (a.i. Benomyl), and biological control agents, <I>Trichoderma harzianum</I> and <I>Bacillus subtilis</I>, on <I>P. patula</I> survival and growth. During the nursery raising period, the pathogen <I>Fusarium circinatum</I> was isolated from all dying material. Field results from the trials indicate that initial (<180-day) post-planting survival is improved if the fungicide Benlate, and to some extent the biological agent <I>T. harzianum</I> was applied at planting. This improvement was, however, no longer significant at 360 days after planting. Reasons for this are not fully explained by the trial data but it is suggested that as fungicide efficacy declines over time, young trees may succumb to disease attack. Given the virulent nature of <I>F. circinatum</I>, it is assumed that mortality in the nursery was principally due to this pathogen, and that mortality in the field may be related to nursery infection. Due to the world wide restriction on the use of Benlate, future research should concentrate on identifying alternative fungicides and/or biological control agents that can be used in nurseries and when establishing disease susceptible species such as <I>P. patula</I>.
Stand biomass and volume estimation for Miombo woodlands at Kitulangalo, Morogoro, Tanzania : research noteSource: Southern African Forestry Journal 2004, pp 59 –70 (2004)More Less
Tree volume and biomass equations developed for Kitulangalo area in Morogoro, Tanzania ignored small branches and small trees. Consequently, this study was carried out to develop new individual tree volume and biomass equations, and assess current regeneration status, biodiversity and yield of miombo woodlands of the area. Volume and biomass equations based on stump diameter for the estimation of volume and biomass of felled trees were also developed. A total of 30 trees were measured for stump diameter (StD), diameter at breast height (dbh) and total height and felled for the determination of volume and biomass. Different tree stem, branch and total volume and biomass models were then fitted. For the determination of current regeneration status, biodiversity and yield, data were collected from three strata: (a) Forest Reserve managed by the Central Government, (b) Forest Reserve under Sokoine University of Agriculture (SUA) and (c) General land (free access by the public). In each stratum, temporary concentric circular sample plots were laid out on transects at 150 m intervals for a 1% sampling intensity. Stand variables such as number of stems per ha, basal area, biomass, volume and plant diversity, were computed for each stratum. The study has revealed the presence of average volumes (m3ha-1) and basal areas (m2ha-1) of: 76.02 <u>+</u> 9.14 and 9.13 <u>+</u> 0.78 for the Government forest reserve, 76.03 <u>+</u> 9.34 and 8.95 <u>+</u> 0.73 for SUA forest reserve, and 43.9 <u>+</u> 7.75 and 7.78 <u>+</u> 1.1 for general land forest. The respective biomass values were 43.56 <u>+</u> 7.06, 41.40 <u>+</u> 4.90 and 29.31 <u>+</u> 6.56 t ha-1. Tree species composition and regeneration status revealed that though disturbed, the public land species composition is not different from the other two strata. More studies should be done on the nursing of the abundant regeneration in the disturbed general land. The developed volume and biomass models are recommended to be used for the miombo woodlands at Kitulangalo area especially where small trees (< 8 cm dbh) are involved.
Effect of rainfall and under-canopy vegetation on the ability to debark Eucalyptus grandis x E. camaldulensis when felled in Zululand, South Africa : research noteSource: Southern African Forestry Journal 2004, pp 71 –75 (2004)More Less
The combined effects of seasonal variation in rainfall and the presence or absence of under-canopy vegetation on soil moisture content may have a negative or positive impact on the ability to debark eucalypts. A study was initiated to investigate these interactions on the ability to debark <I>Eucalyptus grandis</I> x <I>E. camaldulensis</I> when felled at eight years in Zululand, South Africa. Following a period of high rainfall (94 mm in 30 days), the presence of under-canopy vegetation did not influence the ability to debark the trees. This ability to debark the trees was reduced following a period of low rainfall (11 mm in 30 days), however, this was even more pronounced in the presence of under-canopy vegetation.
Author W.J.A. LouwSource: Southern African Forestry Journal 2004, pp 77 –86 (2004)More Less
The more important events and developments in the history of the forest industry are summarized. The industry matured and expanded during this period in a number of aspects of which increase in exports and the emergence of the private sector as the main driver are the most significant. The development of the industry is described under the following headings: forest policy and industry organisations, ownership and commercialisation, afforestation, economics, outsourcing, protection, research, education and training, promotion of the industry, and associations.
Source: Southern African Forestry Journal 2004, pp 89 –91 (2004)More Less
Extracted from text ... SAFJ Index 2003 SA FORESTRY JOURNALS INDEX: No 197, No 198, No 199 Note: This is an Abbreviated Index. Paper title shown under name of main author only. 193/15(9pp) means - Journal No 193 Page 15 Pages 9 'et al' means - More than a single author Author Title Journal Email address Abeli W S et al Socio-economic impact of ox skidding project to the surrounding villages of Mount Meru forest plantations, Northern Tanzania. 198/45(7pp) firstname.lastname@example.org Ackerman P et al Reverting urban exotic pine forests to Macchia and indigenous forest vegetation, using cable-yarders on the slopes of Table Mountain, South ..