Browsing by Author "Syampungani, Stephen"

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    Age and growth rate determination using growth rings of selected miombo woodland species in charcoal and, slash and burn regrowth stands in Zambia
    (2010) Syampungani, Stephen; Geldenhuys, Coert J.; Chirwa, Paxie W.
    The field of dendrochronology has not been widely applied in tropical species because many scientists generally perceive that such species rarely produce distinct growth rings. This study was undertaken to determine if the key Miombo species produce distinct growth rings and to determine the relationship between the number of growth rings and age of the tree and stem diameter. The results showed a high correlation between number of growth rings and stand age for both charcoal (P < 0.001, r = 0.9246) and slash and burn (P < 0.001, r = 0.9019) regrowth stands. Additionally, the study has revealed high mean annual ring width values ranging from 4.4 to 5.6 mm in both charcoal and slash and burn regrowth stands. The pattern of ring development per year and the mean annual ring width values provide a basis for the use of ring counts in determining the age of Miombo regrowth stands and predicting the merchantable age for key Miombo woodland species. The results can therefore be used in planning the cutting cycles in Miombo woodlands. However, the phenomenon of missing growth rings suggests that the influence of environment in the use of growth rings in age determination need to be considered in areas that experience droughts.
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    Vegetation change analysis and ecological recovery of the copperbelt Miombo woodland of Zambia
    (Stellenbosch : University of Stellenbosch, 2009-03) Syampungani, Stephen; Geldenhuys, Coert J.; Chirwa, Paxie W.
    ENGLISH ABSTRACT: The study aimed at developing a new understanding of the Miombo woodland recovery dynamics when exposed to single tree selection, slash & burn agriculture and charcoal production. Five specific studies were conducted to examine different parts of this overall study: Miombo woodland utilization, management and conflict resolution among stakeholders; speciesstem curves as a tool in sampling the development of Miombo woodland species richness in charcoal and slash & burn regrowth stands over time; the impact of human disturbance on the floristic composition of Miombo woodland; regeneration and recruitment potentials of key Miombo woodland species after disturbance; and age and growth rate determination using selected Miombo woodland species. Different methods were developed for each specific study. The study of woodland utilization and management employed semi-structured and key informant interviews. STATISTICA statistical package version 6.0 was used for data collation and analysis. Chi-square tests were used to show levels of significance in differences that existed between different user groups. Species-stem curves were used to determine the sample size to assess Miombo woodland dynamics in regrowth stands after slash & burn and charcoal production, and a fixed-area method was used for the mature woodland stands. The study sites in each of three study areas were selected to represent ages ranging from 2 to 15+ years since each disturbance was terminated. The undisturbed woodland was chosen to act as a control. Various analyses using the STATISTICA statistical package and CANOCO version 4.0 were conducted to understand responses of Miombo woodland to these different disturbances. The research revealed that single tree selection, slash & burn agriculture and charcoal production are the main forms of Copperbelt Miombo woodland utilization which will always be there. Additionally, the the Miombo woodland stands were characterized based on the size class profile they exhibit on exposure to human disturbance factors through forest utilization. The characterization has revealed that the woodland is dominated by light demanding species. As such single tree selection harvesting does not support the regeneration and establishment of the timber species which are canopy species under shade conditions. This implies that selection harvesting of timber species, although it appears to be a non event in terms of disturbance at stand level may be a disaster at population level. The study also revealed that clearing of the woodland for either slash & burn agriculture or charcoal production results in enhanced regeneration and establishment of the dominant Miombo woodland species. The study concludes that charcoal production and slash & burn agriculture are important components to which the woodland ecosystem is adapted. As such these disturbance factors may be considered as incorporated disturbances. It is recommended from the study that woodland utilization and management should integrate charcoal production and slash & burn agriculture into forest management. Cutting cycles should be based on growth rate of the selected species. Timber species harvesting should go side by side with these disturbance factors so as to open up the canopy in order that maximum sunlight can reach the regeneration stock. The study also brings out the other management and utilization opportunities (such as managing for Uapaca kirkiana and Anisophyllea boehmii fruits) that arise from different development stages of the woodland. Lastly, it is recommended to ascertain the optimum gap sizes for both charcoal production or slash & burn agriculture which would still support the Miombo woodland recovery.