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Vegetation change analysis and ecological recovery of the copperbelt Miombo woodland of ZambiaSyampungani, Stephen 03 1900 (has links)
Thesis (PhD (Forest and Wood Science))--University of Stellenbosch, 2009. / 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. / AFRIKAANSE OPSOMMING: Hierdie studie is gedoen om ‘n nuwe begrip te ontwikkel vir die hersteldinamika van Miombo
boomveld na onderwerping aan enkelboomseleksie, kap & brand lanbou en houtskoolproduksie.
Vyf spesifieke studies is gedoen om verskillende komponente van die total studie te ondersoek:
benutting, bestuur en konflikresolusie tussen gebruikers van Miombo boomveld; species-stam
kurwes as ‘n instrument in die bemonstering van die ontwikkeling van Miombo boomveld
species-rykdom oor tyd na afloop van houtskoolproduksie en kap & brand landbou; die impak
van menslike versteuring op die floristiese samestelling van Miombo boomveld;
verjongingspotensiaal van sleutelsoorte in Miombo boomveld na versteuring; en bepaling van
ouderdom en groeitempo in ge-selekteerde Miombo boomveldsoorte. Verskillende metodes is
ontwikkel vir elke spesifieke studie. In die studie van boomveldgebruik en –bestuur is semigestruktureerde
en sleutel-informant onderhoude gebruik. Die STATISTICA statistiese packet
weergawe 6.0 is gebruik vir dataverwerking en -ontleding. Chi-kwadraat toetse is gebruik om
vlakke van betekenisvolheid te toon wat bestaan tussen verskillende gebruikersgroepe. Speciesstamkruwes
is gebruik om monstergrootte te bepaal vir die evaluering van Miombo
boomvelddinamika in hergroeiopstande na kap & brand en houtskoolproduksie, terwyl vastegrootte
persele gebruik is vir volwasse boomveldopstande. Die studieplekke in elk van drie
studiegebiede is geselekteer om verskillende ouderdomme tussen 2 en 15+ jaar na be-eindiging
van die versteuring te verteenwoordig. Onversteurde boomveld is gebruik as kontrole. Verskeie
ontledings, met die STATISTICA statistiese pakket en CANOCO weergawe 4.0 is gedoen om
die reaksie van Miombo boomveld op die verskillende versteurings te verstaan. Die navorsing
het getoon dat enkelboomseleksie, kap & brand landbou en houtskoolproduksie is die hoof
vorme van Copperbelt Miombo boomveld benutting wat altyd daar sal wees. Verder is die
Miombo boomveldopstande gekarakteriseer gebaseer op die grootteklasprofiel wat hulle vertoon
na menslike versteuringsfaktore in die vorm van boomveldbenutting. Die karakterisering het
getoon dat die boomveld gedomineer word deur ligeisende soorte. Daarom ondersteun
enkelboomseleksie nie die verjonging en vestiging van die dominante houtsoorte wat
kroonsoorte is onder skadutoestande. Dit impliseer dat selektiewe inoesting van houtsoorte,
alhoewel dit voorkom as ‘n onbelangrike gebeurtenis in terme van versteuring op opstandsvlak,
‘n ramp is op populasievlak. Die studie het ook getoon dat skoonmaak van die boomveld vir of
kap & brand landbou of houtskoolproduksie, lei tot verbeterde verjonging en vestiging van die
dominante Miombo boomveldsoorte. Die studie lei tot die gevolgtrekking dat
houtskoolproduksie en kap & brand landbou belangrike komponente is waarby die
boomveldsisteem aangepas is. Daarom kan hierdie versteuringsfaktore beskou word as ingeslote
versteurings. Vanuit die studie word daarom aanbeveel dat boomveldbenutting en –bestuur
houtskoolproduksie en kap & brand landbou binne die bosbestuur integreerd moet word.
Kapsiklusse moet gebaseer word op die groeitempos van geselekteerde soorte. Inoesting van
houtsoorte moet saamloop met hierdie versteuringsfaktore sodat die kroondak oopgemaak kan
word sodat maksimum sonlig die verjonging bereik. Die studie bring ook na vore die bestuur en
benuttingsgeleenthede (soos bestuur vir die vrugte van Uapaca kirkiana en Anisophyllea
boehmii) wat voorkom in verskillende ontwikkelingstadiums van die boomveld. Laastens word
aanbeveel dat die optimum openinggroottes vir beide kap & brand en houtskoolbereiding wat herstel van Miombo boomveld ondersteun, bepaal.
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