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Evaluation of the performance of joint forest management (JFM) programme : case of Dambwa Forest Reserve in Livingstone District, ZambiaPhiri, Maxwell 12 1900 (has links)
Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2009. / jfl2010 / ENGLISH ABSTRACT: The past forest management strategies in Zambia did not allow participation of local communities in the management of Forest Reserves and sharing of benefits. The Zambia forest sector was reviewed between 1987 and 1997 culminating into the National Forestry Policy of 1998 and Forests Act of 1999, which provided for joint or participatory forestry management and share of derived benefits. In 2000, the Forestry Department initiated a pilot project to develop and implement JFM. This study was conducted in Dambwa JFM area in Livingstone to evaluate local people’s participation in JFM; perceptions on the effect of JFM on local livelihoods; and the impact of JFM on forest condition. The study was conducted through the use of household questionnaires, interviews with key informants, focus group discussions, field observation, and vegetation assessment.
The results showed that more than half (68%) of the respondents were aware of JFM and almost the same number (64%) participated in JFM project. Participation of men in JFM activities was higher than women, although more women attended meetings than men. The results further showed that local management structures existed at district, forest area and village levels for coordination of JFM activities. Forest User Groups (FUGs) were also established in the area. The prominent FUG was the Mungongo oil pressing and was the only FUG functional at the time of the study. Forest Management Committee, Village Resources Management Committee and FUG members were found to be more involved in JFM activities than other members of the local community. Only a small number (8%) of local people reported improvement in household socio-economic conditions after the introduction of JFM, while the majority (79%) perceived the Forestry Department to be the major beneficiary in the JFM. The study revealed that there was a loss of enthusiasm in JFM among local people largely due to the absence of economic benefits and limited decision-making powers. However, the relationship between local people and Forestry Department was reported to have improved.
The overall forest stocking was found to be low (219 SPH) with nearly all (90%) of the stems below 30 cm DBH, including the selected valuable tree species of Baikiaea plurijuga, Pterocarpus angolensis, Guibourtia coleosperma, Afzelia quanzensis and Colophospermum mopane. This implies that the forest area was previously overexploited rendering it uneconomical for commercial exploitation to provide benefits to local people on sustainable basis. However, the results showed a lot of saplings (10,000 SPH) in the Forest Reserve signifying adequate regeneration, including that of the valuable species, except for Afzelia quanzensis and Guibourtia coleosperma. The abundant natural regeneration implies that there was adequate forest protection and management following the introduction of JFM, which enhances regeneration.
It is recommended that the Forestry Department should continue with public awareness on JFM to increase understanding and stakeholders’ involvement. The Forests Act of 1999 should be commenced and amended to support full implementation of JFM. The value of the forest also needs to be enhanced to increase benefit for local people and long-term conservation.
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Analysis of the market structures and systems for indigenous fruit trees: the case for Uapaca Kirkiana in ZambiaMoombe, Kaala Bweembelo 03 1900 (has links)
Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2005. / This study is about marketing of Uapaca kirkiana fruit in Zambia, a fruit that has great economic
value especially among the rural and urban poor. It contributes to general food security. In
southern Africa, farmers and other stakeholders have identified Uapaca as a priority species for
domestication. Current agroforestry initiatives are promoting integration of indigenous trees into
farming systems to provide marketable products for income generation. Domestication of trees
however, depends on expanding the market demand for tree products. There is considerable
evidence that expanding market opportunities is critical for the success of domestication
innovations but farmers have been introduced to domestication with little consideration for
marketing. The existing market potential can be achieved through sound knowledge on markets
and marketing. Information on the marketing of Uapaca fruit is inadequate. This study,
therefore, aimed at generating information on the marketing of Uapaca kirkiana fruit, including
the basic conditions of demand and supply of the fruit.
The main study was conducted in Chipata and Ndola districts in the Eastern and Copperbelt
provinces respectively, while fruit pricing was conducted in Lusaka district in Lusaka Province.
Questionnaires and participatory research methods were used to collect the data. A total of 37
markets involving 49 collectors, 59 retailers, 189 consumers and 20 government forest workers
are included in the study.
The study reveals that there is demand for the fresh and secondary products of the fruit and hence
substantial fruit trading exists in Zambia. However, the marketing system is characterised by
underdevelopment. There is insufficient capacity to satisfy the demand for the fruit and
institutional /policy support to Uapaca fruit market expansion. Currently, only basic technology
for product development exists. The results suggest a need to address policy and capacity
development for expansion of Uapaca kirkiana fruit industry. To improve the Uapaca trade
industry, the study proposes developing and scaling up policy strategies, fruit processing sector,
research-extension-trader-agribusiness linkages, infrastructure development and knowledge
generation for improved understanding of the Uapaca fruit markets.
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A method for the non-destructive determination of the knotty core sizes of standing Pinus patula trees, based on ring width assessments at breast height and the pruning historyMunalula, Francis 03 1900 (has links)
Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The objective of this study was to develop and assess a methodology of using pruning information (age and height) and ring width measurements on increment core samples taken at breast height from standing pruned Pinus patula trees for modeling the knotty core sizes in the pruned section of a tree. A total of 170 trees from 17 compartments, representing a wide variety of growth sites from the Mpumalanga escarpment, were selected and destructively sampled. Sample trees were selected to represent the productive timber volume available from the compartments using stratified sampling. Sample discs were removed at breast height (1.3m) and at six meter height. After drying and sanding, the cross-sectional surfaces of one surface of each of the discs were scanned on a document scanner and the ring widths measured, using an image analysis program. A preliminary study, using 30 discs, was undertaken to ascertain the appropriate number of radii per disc to measure. A comparison between results of two opposite radii, as opposed to four radii, showed that the difference in mean ring width resulting from the two approaches was statistically not significant. In practice this means that for ring width assessment, sampling of increment cores opposite to one another at breast height would be sufficiently accurate to study average ring width variation across the radius of a tree. A study was also conducted to determine to what accuracy ring widths at six metre height could be predicted from breast height measurements. It was shown that cumulative growth at six metre height can be predicted from cumulative growth at breast height, site index and cambial age at breast height as independent variables (R2 = 0.96). Ring width measurements at breast height can, therefore, be used to predict incremental growth throughout the pruned section. Combined with available information on the pruning history of a stand (pruning heights and pruning age), this study proved that quantitative knowledge on incremental growth can be used as a basis for estimating changes in knotty core sizes along the entire pruned section of the stem.
Analysis of variation for the entire data set from ring width measurements showed that there was far greater variation in knotty core percentages (the percentage of diameter occupied by knotty core) between different compartments than within compartments. Within a tree, the knotty core percentages between three stem sections, 0-2.4m, 2.4–4.8m, and 4.8-7m, were found to increase significantly from the bottom section (49.1%) to the top section (65.4%).
A single 2.4m log from the pruned section of each tree was removed and processed into sawn timber at a sawmill. After drying of the boards, a sub-sample of sawn boards from 17 logs, one log from each compartment, was selected and reconstructed into log form. From the reconstructed log (reconstructed to represent their original position in the log) the actual knotty core size was estimated by measuring the distance from the pith to the end of the branch stub. A comparison of the actual knotty core sizes and the modelled knotty core sizes of a sub-sample of trees showed only a modest relationship (R2 = 0.62). Reasons for this might be variability in pruning quality, inaccurate pruning records, nodal swellings and the methodology used to measure the actual knotty core sizes.
Knowledge of knotty core sizes of standing trees can be used for many different purposes. Two applications that were assessed and found to be useful include decision support for cross cutting logs and for sawmill production planning purposes. Sawmill simulation software was used to evaluate value -and grade recoveries under different scenarios. Results showed that cross-cutting the pruned sections of logs from a compartment with large within-tree knotty core size variation into shorter logs, as opposed to keeping the pruned sections as single logs, result in increases in grade and value recovery. It was also shown that sawing of pruned logs from compartments with relatively small knotty cores, results in much better grade recoveries than logs from compartments with relatively large knotty cores (this information will be useful for production planning purposes). It can be concluded that the methodology proposed to reconstruct knotty cores from tree ring measurements has the potential to be used as a decision aid in the forest and forest products industry.
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Weathering behaviour of Colorado (Eucalyptus camaldulensis and Eucalyptus tereticornis) and Balau (Shorea spp.)Smit, Norman Hein 03 1900 (has links)
Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Balau, a group consisting of 21 Shorea species, is widely used for outdoor application. In
South Africa, Balau is one of the most popular materials used for decking. Due to the
increasing scarcity of Balau, it is of economic importance to investigate the possibility of a
substitute timber for decking material. One possible timber could be Colorado, a mixture
containing one or more of the following: Eucalyptus camaldulensis, Eucalyptus tereticornis
and their hybrids. These two species and their hybrids are extensively cultivated in countries
such as Australia, India and parts of South America because of their short rotation period and
easy adaptability to a wide variety of soil and climatic factors. The timber was initially
utilized as raw material for the pulp and paper industry but is now gaining importance in
structural uses like furniture, flooring and decking.
The aim of this exploratory study was to investigate relevant material properties and to
examine the natural and accelerated weathering behaviour of Colorado and Balau to predict
Colorado’s suitability as decking material.
It was found that Colorado had smaller vessel lumina, fewer vessels/m2 and smaller rays than
Balau and had a higher density than Balau. Although both timbers had a relatively low FSP,
Colorado’s FSP was 2.3 percentage points higher than Balau’s. The swelling coefficients
(radial and tangential) of Colorado were slightly higher than Balau’s but Colorado’s lower
swelling anisotropy can result in a lower tendency to twist in service. Colorado had a higher
water soluble extractive content than Balau, which can lead to the rapid initial colour changes
when the timber is exposed uncoated.
The weathering performance of Colorado and Balau was investigated by exposing samples in
a QUV accelerated weathering apparatus and to natural weathering at an inland and a marine
location. During weathering Colorado showed a slightly higher colour change ( E*) than
Balau. Balau showed a higher increase in roughness (Rz), surface checking and check
formation than Colorado. Colorado showed slightly more cup than Balau, however, Balau
showed much larger amounts of twisting than Colorado. No statistically significant
differences were found between the hydrophobicity of the two timbers. A coating was
effective in increasing the initial hydrophobicity of samples and could maintain a relatively
hydrophobic surface during weathering. No statistically significant differences were found in
the effect of sample cut on timber species surface wettability. Although only long term
exposure studies and using substantially more samples can confirm its weathering
performance, the results of this exploratory weathering study indicated that Colorado can
successfully be used as a substitute decking material for Balau. / AFRIKAANSE OPSOMMING: Balau, ‘n houtsoort wat ongeveer 21 Shorea-spesies verteenwoordig, word wyd in
buitenshuise aanwendings benut. In Suid-Afrika is Balau een van die mees gewilde materiale
wat vir dek-doeleindes gebruik word. As gevolg van die toenemende skaarsheid van Balau, is
dit van ekonomiese belang om die gebruik van ‘n moontlik plaasvervangende houtsoort vir
dek-materiaal te ondersoek. Colorado, ‘n mengsel van een of meer van die volgende:
Eucalyptus camaldulensis, Eucalyptus tereticornis en hibriede daarvan, kan as ‘n moontlike
plaasvervanger gebruik word. Hierdie twee spesies en hulle hibriede word op groot skaal in
lande soos Australië, Indië en dele van Suid-Amerika gekweek vanweë hul kort rotasieperiode
en goeie aanpasbaarheid by ‘n wye verskeidenheid grond- en klimaatsfaktore. Die spesies is
aanvanklik as grondstof in die pulp- en papierbedryf gebruik maar word tans al hoe
belangriker in strukturele aanwendings soos byv. meubels, vloer- en dek-materiaal. Die doel
van hierdie verkennende studie was om relevante materiaaleienskappe te ondersoek en om die
versnelde en natuurlike verweringsgedrag van Colorado en Balau vas te stel om sodoende ‘n
aanduiding van die geskiktheid van Colorado as dek-materiaal te kan kry.
Daar is gevind dat Colorado kleiner vat-lumina, minder vate/m2 en kleiner strale as Balau
besit en dat Colorado ‘n hoër digtheid het as Balau. Alhoewel beide houtsoorte relatiewe lae
veselversadigingspunte (VVP) besit, is Colorado se VVP 2.3% persentasiepunte hoër as dié
van Balau. Die swellingskoëffisiente (radiaal en tangensiaal) van Colorado is effens hoër as
dié van Balau, maar Colorado se laer swellingsanisotropie kan op ‘n kleiner neiging tot
skeeftrek dui. Colorado het ‘n hoër wateroplosbare ekstrakstofinhoud as Balau bevat, wat tot
aanvanklik vinnige kleurveranderings kan lei wanneer die hout sonder oppervlaktemiddel
blootgestel word.
Die verweringsgedrag van Colorado en Balau is ondersoek deur monsters aan versnelde en
natuurlike verwering bloot te stel. Eersgenoemde is in ‘n QUV versnelde verweringsapparaat
uitgevoer en laasgenoemde in ‘n binnelandse en ‘n mariene lokaliteit. Tydens verwering het
Colorado ‘n effens hoër kleurverandering ( E*) as Balau getoon. Balau het ‘n hoër toename
in rofheid (Rz), oppervlaktekrake en kraakvorming as Colorado getoon. Colorado het effens
meer kromgetrek terwyl Balau meer skeefgetrek het as Colorado. Geen statisties beduidende
verskille kon tussen die waterwerende eienskappe van die twee houtsoorte vasgestel word nie.
‘n Oppervlakbedekking was effektief om die aanvanklike toename in waterwerende vermoë te
verhoog en gedurende verwering te kon behou. Geen statisties beduidende verskille kon
tussen die invloed van snit van die monster op die oppervlaktebenatbaarheid van die
houtsoorte vasgestel word nie. Alhoewel slegs langtermyn blootstellingstudies en die gebruik
van beduidend veel meer monsters die verweringsgedrag kan bevestig, dui die resultate van hierdie verkennende ondersoek aan dat Colorado suksesvol as ‘n plaasvervangende dekmateriaal
vir Balau gebruik kan word.
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The use of time study, method study and GPS tracking in improving operational harvest planning in terms of system productivity and costsOdhiambo, Benedict O. 12 1900 (has links)
Thesis (MScFor (Dept. of Forest and Wood Science)--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This study aims to quantify the benefits of implementing an operational
harvesting plan in forest harvesting operations. This is to be achieved by
comparing productivity and costs from unplanned and planned harvesting
operations. The study was conducted on a Pinus radiata plantation owned
by Mountain to Ocean Forestry Company (Pty) Ltd (MTO) located near the
town of Grabouw in the Western Cape Province of South Africa.
MTO conducts harvesting operations using semi-mechanised tree-length
harvesting systems. A wheeled H67 Clark Ranger cable skidder is used to
extract tree-lengths from infield to the landing. Data was obtained both
manually (work study) and from GPS tracking. Choking and dechoking data
was obtained through time and method studies. GPS tracking was used to
measure travel loaded and travel empty times, as well as travel distances
and travel speeds. The aim of using both manual techniques and GPS
tracking was to obtain detailed and spatially accurate information about the
operation. The operating costs were estimated using South African
Harvesting and Transport Costing Model.
Productivity of the newly introduced tagline system (45.97 m³/pmh) exceeded
that of mainline system (37.85 m³/pmhh) by 26%. The unit production cost of
using tagline system (R20.21/m³) was 10% lower than the unit production
cost of using mainline system (R22.54/³3). There were no benefits to be
gained from improving the level of skid trail construction by removal of
logging residue or cutting down stumps to as near the ground level as
possible. A combination of manual (time and method studies) data collection
and GPS tracking provided more detailed and accurate information on the
semi-mechanised harvesting system. / AFRKAANSE OPSOMMING: Hierdie studie beoog om die voordele van die uitvoering van 'n operasionele
inoestingsplan te kwantifiseer. Dit word bereik deur produktiwiteit en kostes
van beplande en onbeplande inoestingswerksaamhede te vergelyk. Die
studie is gedoen in Pinus radiata opstande van Mountain to Ocean Forestry
Company (Pty) Ltd (MTO) naby Grabouw in die Wes-Kaap provinsie van
Suid Afrika.
MTO gebruik semi-gemeganiseerde boomlengte inoestingstelsels in hul
inoestingswerksaamhede. . H67 Clark Ranger wielsleeptrekker met kabel en
wenas is gebruik om boomlengtes van die veld na die pad te sleep. Data is
versamel deur van beide hand (werkstudie) en GPS-opsporing gebruik te
maak. Afhaak en aanhaak data is verkry deur van tyd- en metodestudies
gebruik te maak. Gelaaide en ongelaaide tyd, spoed en afstande is met
behulp van die GPS gemeet. Deur van beide hand en GPS
versamelingsmetodes gebruik te maak, kon omvattende sowel as ruimtelik
akkurate inligting oor die werksaamhede verkry word. Die bedryfskostes is
verkry van die South African Harvesting and Transport Costing Model.
Produktiwiteit van die nuut ingestelde verbindingslynstelsel (45.97 m³/pmh)
het die hooflynstelsel (37.85 m³/pmh) met 26% oorskry. Die
eenheidsproduksiekoste van die verbindingslynstelsel (R20.21/m³) was 10%
laer as die eenheidsproduksiekoste van die hooflynstelsel (R22.54/m³). Daar
was geen voordeel in die verbetering van die sleeppad konstruksie deur afval
te verwyder of stompe nader aan die grondvlak af te sny nie. 'n Kombinasie
van hand (tyd- en metodestudies) dataversameling en GPS-opsporing het
meer akkurate en omvattende inligting oor die semi-gemeganiseerde
inoestingstelsel verskaf.
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The assessment of fire history in plantations of Mpumalanga NorthVan der Sijde, J. H. R. (Jan Herman Robert) 12 1900 (has links)
Thesis (MScFor) -- Stellenbosch University, 2003. / ENGLISH ABSTRACT: Fire is a threat to all forest plantations. As a result, growers are forced to take active
measures to reduce the incidence and extent of fires in their plantations.
This thesis is an attempt to collate 846 fire records for eight Komatiland Forests
(KLF) plantations in Mpumalanga North for the period 1950 to 1999. Up to now,
these reports and the information therein, were not utilised by KLF for planning or for
evaluating fire management practices. The only other studies in South Africa, using
similar data, were conducted by LeRoux (1988) and Kromhout (1990).
A brief background of the forestry industry in South Africa, and in particular
Mpumalanga is presented. The main text of the report covers a presentation on fire
causes, extent of damage (both in area and in Rand value) and various aspects
related to time of ignition and response times. A detailed analysis was done to
identify possible relationships between the variables related to compartment, climate
and different fire suppression activities.
A cause and frequency prediction model was developed that will assist fi re managers
in identifying and determining probabilities of fires per cause. Statistical guidelines
regarding the planning of fire management around fires caused by honey hunters,
lightning, work-related factors, and the activities of people (public, own labour,
contractors) are presented.
Conclusions were drawn from the results of the analyses of the fire data, which
covered a period of 47 years. Recommendations regarding guidelines for strategic
fi re management for the Mpumalanga North plantations were made. The main
conclusions are:
• Statistics on previous fires are very useful in fire management planning
as it supplies valuable information on fire causes, time of ignition , past
performance related to response times, fire fighting times and damaged
caused.
•
•
•
•
The average area lost due to fires in the study area is 209.9 ha or
0.43% of the plantation area per annum.
People-related fires (arson, smokers, picnickers, children and
neighbours) caused most of the wild fires (48%), followed by lightning
(22%).
Some plantations performed poorly, with the occurrence of up to
double the number of fires per 1 000 ha of plantation compared to other
plantations in the same geographic area.
There are definite patterns in the frequency of fires per cause with
month of the year. These patterns are valuable for the development of
strategies to manage fires caused by honey hunters, lightning fires and
work-related fires. / AFRIKAANSE OPSOMMING: Brande is 'n bedreiging vir aile bosbou plantasies. Dit is dus noodsaaklik dat
kwekers maatreeHs tref om die voorkoms en omvang van brande in plantasies te
beperk.
Hierdie tesis poog om 846 vuurverslae se inligting te ontleed ten opsigte van agt
Komatiland Forests (KLF) plantasies in Mpumalanga Noord vir die tydperk 1950 tot
1999.
Tot op hede is min van die inligting wat in die verslae vervat is deur KLF vir
beplanning- en evalueringsdoeleindes ten opsigte van brandbestuur gebruik. Die
enigste soortgelyke studies wat op brandverslagdata in Suid-Afrika gedoen is, is
gedoen deur Le Roux (1988) en Kromhout (1990).
'n Kort agtergrond oor die bosbouindustrie in Suid-Afrika en spesifiek Mpumalanga
word gegee. Die tesis gee 'n oorsig oor brandoorsake, skade wat deur brande
veroorsaak word (oppervlakte sowel as finansieHe waarde) en verskeie aspekte
rakende brandbestuur soos tyd van ontstaan en reaksietye. Data is volledig ontleed
om moontlike verwantskappe te probeer vind tussen vak-, klimaat- en
brandbestuursveranderlikes.
'n Oorsaak- en frekwensievoorspellingsmodel is ontwikkel wat brandbestuurders sal
help om waarskynlikhede van brande per oorsaak te identifiseer. Statistiese riglyne
ten opsigte van bestuursbeplanning vir weerligvure, brande deur heuninguithalers,
brande as gevolg van plantasiewerksaamhede en ook brande deur mense (publiek,
eie arbeid en kontrakteurs) is daargestel.
Brandrekords wat oor 'n periode van 47 jaar gestrek het, is ontleed. Afleidings wat
uit die resultate gemaak is, kan benut word om riglyne daar te stel vir strategiese
brandbestuur in Mpumalanga Noord plantasies. Die hoof gevolgtrekkings is:
• Statistiek van vorige vure is baie nuttig in brandbestuursbeplanning
aangesien dit waardevolle inligting verskaf oor brand oorsake, tyd van ontstaan, historiese werkverrigting rakende reaksietye en blustye,
sowel as skade wat veroorsaak is.
Die gemiddelde oppervlakte beskadig in die studie area is 209.9 ha, of
0.43% van die plantasie oppervlakte per jaar.
Menslike aktiwiteite (brandstigting, rakers, piekniekvure, kinders en
vure van bure) het die meeste brande veroorsaak (48%), gevolg deur
weerlig (22%).
Sommige plantasies het swak gevaar en het tot soveel as dubbel die
aantal vure per 1 000 ha plantasie gehad in vergelyking met ander
plantasies in dieselfde geografiese gebied.
Daar is duidelike patrone gevind in die frekwensie van brande per
oorsaak oor maande van die jaar. Hierdie patrone is nuttig vir die
ontwikkeling van bestuurstrategie vir brande wat veroorsaak word deur
heuningversamelaars, weerlig en werkverwante aktiwiteite (plantasieaktiwiteite).
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Trees for the Western Transvaal selected on the basis of arboretum trialsPoynton, R. J. 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 1968. / ENGLISH ABSTRACT: Trees are needed on the semi-arid Highveld of
the western Transvaal for shelterbelts, woodlots, fodder,
honey, shade and ornament.
A brief history of tree planting in the area,
more particularly at Lichtenburg and Potchefstroom, is
given.
Relatively few species can be grown successfully in the western Transvaal because of the unfavourable
climate. Hot, dry winds blow almost continuously off
the Kalahari between August and October before the first,
spring rains; cold winds and frosts are experienced in
winter, although the summers are hot; the rainfall is
erratic and low, averaging about 600 mm. a year and
occurring mainly in the form of heavy thunderstorms
during summer; hail is common.
The geology of the area is complex. In the
north-west an overburden of wind-transported sand obscures
the underlying formations. The soils are mostly of a
light, sandy or loamy consistency, with a fairly high
base-saturation value. Concretions, sometimes forming
a continuous hardpan, are characteristic of certain
types.
Various indigenous trees are found in some
localities. These are small,and are mainly confined to
rocky hillsides and stream banks. In the past they have
been much exploited for rough building timber, fence posts
and firewood. Their growth is very slow, and exotics
have proved to be more vigorous as well as more useful
in cultivation.
Possible adaptations of trees to dry climates
are discussed. It is concluded that'apparent adaptations
observed in the field are of little value in selecting
trees for dry areas. No practical alternative therefore
exists at this stage to the introduction of species from
.areas with a similar climate and testing these under
local conditions. Parts of the world having a climate
similar to that of the western Transvaal are in.dicated.
Summarised results of species trials in the
western Transvaal are given in tabular form, and recommendations
for tree planting in the area are made.
In an appendix, trials of BB species in
arboreta at Lichtenburg and Potchefstroom are fully
described and discussed.
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Impact of fuelwood quality and quantity on rural households’ energy use in Omusati region in North-West of NamibiaHainduwa, Feliciana Ndapewa 03 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Wood scarcity remains the main challenge for many rural households who still rely on natural
resources for energy needs. This study aimed to investigate the relationship between fuel
use and quality and quantity of fuel in two rural villages (Ongulumbashe and Onaitembu) in
the Omusati Region of Namibia. It investigated the impact of fuel quality and quantity and
the corresponding sales of firewood on households’ energy consumption.
Data was collected between April and June 2012 from the two villages by means of
questionnaire surveys, biomass assessment and laboratory assessment. Interviews were
conducted with seventy-seven households, four firewood sellers, government officials, and
local leaders. The study quantified the amount of fuelwood consumed and collected per
household per week using user-recall and physical measurement, respectively. The most
preferred fuel species or fuel materials were identified and their physical properties, calorific
value, moisture content, ash content and density were measured under laboratory
conditions.
Differences between the two villages in terms of fuelwood collected and consumed were
found. Due to wood scarcity households from Onaitembu village used other alternatives
(buying fuelwood and cutting live firewood) rather than collecting dead firewood. The study
found a link between fuelwood use, quality and quantity, with households changing their
consumption and harvesting based on season, fuelwood demand and availability of
fuelwood. The average weekly fuelwood consumption per household ranged from 66 kg to
79 kg for a firewood abundant area and from 59 kg to 67 kg for an area with a shortage of
firewood.
Mopane was the most preferred species due to its ability to burn efficiently and its
abundance. Wood scarcity affected households economically, culturally and nutritionally.
The study found that households in degraded areas spend an average of N$ 50 per week on
fuelwood, and many households depended on government grants and small cash income
activities. The study found that the government, through the Ministry of Agriculture, Water
and Forestry, is trying to improve rural households’ energy use by constructing firewood
outlets. The study concluded that there is a high level of illegal trade in firewood that will require
government to increase the number of staff in the region as well as to strengthen its policy on
cross-border trading. There is an imbalance in fuel species use in areas of rich biomass and
over-utilization of resources in degraded areas. These require the Directorate of Forestry to
educate the community about the value of other possible fuel species and the impact of
harvesting live firewood on households’ livelihood and on the environment. / AFRIKAANSE OPSOMMING: Houtskaarsheid bly die grootste uitdaging vir baie landelike huishoudings, wat nog steeds
staatmaak op natuurlike hulpbronne vir energie behoeftes. Hierdie studie het gepoog om die
verhouding tussen brandstof gebruik en kwaliteit en kwantiteit van brandstof in twee
plattelandse dorpies (Ongulumbashe en Onaitembu) in die Omusati-streek van Namibië te
ondersoek. Die impak van brandstof kwaliteit en kwantiteit en verkope van brandhout op
huishoudings se energie gebruik is ondersoek.
Data is ingesamel in April en Junie 2012 in die twee dorpe deur middel van vraelys
opnames, biomassa assessering en laboratorium ontledings. Onderhoude is gevoer met 77
huishoudings, vier brandhoutverkopers, regeringsamptenare, en plaaslike leiers. Die studie
het die hoeveelheid vuurmaakhout verbruik en versamel per huishouding per week
gekwantifiseer deur gebruik te maak van gebruikergeheue en fisiese meting van
vuurmaakhout. Die mees gewilde brandstof spesies of brandstof materiaal is geïdentifiseer
en hul fisiese eienskappe, kaloriewaarde, voginhoud, asinhoud en digtheid is onder
laboratorium toestand gemeet.
Verskille tussen die twee dorpe in terme van brandhout versamel en verbruik is gevind. As
gevolg van houtskaarsheid gebruik huishoudings in ONA ander alternatiewe energiebronne,
soos om brandhout te koop of om vars hout te saag, in plaas van om dooie hout te versamel.
Die studie het ‘n skakel gevind tussen brandhout gebruik en die gehalte en hoeveelheid wat
beskikbaar is. Huishoudings het hulle brandhout verbruik aangepas by die seisoen,
aanvraag en beskikbaarheid van brandhout. Die gemiddelde weeklikse brandhout verbruik
per huishouding het gewissel tussen 66 kg tot 79 kg vir 'n area met ‘n oorvloed van
brandhout en 59 kg tot 67 kg vir 'n gebied met 'n tekort aan brandhout.
Mopanie was die mees gewilde spesie as gevolg van sy besikibaarheid en vermoë om
doeltreffendheid te brand. Houtskaarstes beinvloed huishoudings op ekonomies, kulturele
en voedings vlakk. De studie het bevind dat huishoudings in ’n area met ‘n houtskaarste
gemiddeld N$50 per week spandeer om brandhout te koop en dat baie huishoudings
afhanklik is van staatstoelaes en klein kontant inkomste-aktiwiteite. Die studie het gevind
dat die regering, deur middel van die Ministerie van Landbou, Water en Bosbou, probeer om landelike huishoudings se energie gebruik te verbeter deur die bou van brandhout
afsetpunte.
Die studie het tot die gevolgtrekking gekom dat daar 'n hoë vlak van onwettige handel in
brandhout is wat sal vereis dat die regering die aantal amptenare in die streek moet
vermeerder en sy beleid rakende handel oor landsgrense heen moet verbeter. Daar is 'n
wanbalans in die gebruik van brandstofspesies in 'n gebied met baie biomassa, en
oorbenutting van hulpbronne in gedegradeerde gebiede. Die Direktoraat van Bosbou moet
die gemeenskape oplei oor die waarde van ander moontlike brandstofspesies en die impak
van die oes van lewendige bome op huishoudings se lewensbestaan en op die omgewing.
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29 |
Biomass modelling of selected drought tolerant Eucalypt species in South AfricaPhiri, Darius 12 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The study aims at developing models for predicting aboveground biomass for selected drought tolerant Eucalyptus (E) species (E. cladocalyx, E. gomphocephala and E. grandis x camaldulensis) from the dry west coast. Biomass models were fit for each of the species and a cross-species model was parameterised based on pooled data for all the three species. Data was based on destructive sampling of 28 eucalypt trees which were 20 years of age and additional five five-year old E. gomphocephala trees. Preliminary measurements on diameter at breast height (dbh), height (h) and crown height were recorded in the field. The sampled trees were then felled and samples of discs, branches and foliage were collected. Density of the wood discs and the bark was determined by a water displacement method and computer tomography scanning (CT-scanner). Stem biomass was reconstructed using Smalian’s formula for volume determination and the calculated densities. Upscaling of the crown was carried out by regression equations formulated by employing the sampled branches. Further assessment was carried out on a sub-sample by subjecting the samples to different drying temperatures in a series between 60 and 105ºC.
Linear models were parameterised by a simultaneous regression approach based on Seemingly Unrelated Regression (SUR) using the “Systemfit” R statistical package. The predictor variables employed in the study were dbh, d2h and h in which the coefficient of determination (R2), Mean Standard Error (MSE) and Root Mean Standard Error (RMSE) were used to determine the goodness of fit for the models. Akaike Information Criteria (AIC) was also used in the selection of the best fitting model. A system of equations consisting of five models was formulated for each Eucalyptus species. The biomass prediction models had degrees of determination (R2) ranging from 0.65 to 0.98 in which dbh and d2h were the main predictor variable while h improved the model fit. The total biomass models were the best fitting models in most cases while foliage biomass had the least good fit when compared to other models. When the samples were subjected to different drying temperatures, stem wood had the largest percentage change of 6% when drying from 60ºC to 105ºC while foliage had the lowest percentage change of less than 2%. / AFRIKAANSE OPSOMMING: Die doel met hierdie studie is om modelle vir die voorspelling van die bogrondse biomassa van drie droogte-bestande Eucalyptus (E) spesies (E. cladocalyx, E. gomphocephala en E. grandis x camaldulensis), gekweek op die droë kusvlakte in Wes-Kaapland, te ontwikkel. Biomassa modelle vir elk van die spesies is gepas en ’n model gegrond op die gekombineerde data van al drie die spesies, is geparameteriseer. Verder is die biomassa variasie onder verskeie droogingstemperature vasgestel. Die data versameling is uitgevoer gegrond op die destruktiewe mostering van 28 Eucalyptus bome wat 20 jaar oud was en ’n bykomende vyf vyfjarige E. gomphocephala bome. Die aanvanklike mates, naamlik deursnee op borshoogte (dbh), boomhoogte (h) en kroonhoogte is in die veld opgemeet. Die gemonsterde bome is afgesaag en monsters van stamhout skywe, takke en die bas is versamel. Die digtheid van die skywe en die bas is deur die waterverplasing metode, en Rekenaar Tomografie skandering (“CT-scanning”) vasgestel. Stam biomassa is rekonstrukteer deur gebruik te maak van Smalian se formule vir die vasstelling van volume en berekende digtheid. Die opskaal van die kroon biomassa is gedoen met behulp van regressie vergelykings van gekose takmonsters. Submonsters is onderwerp aan ’n reeks van verskillende drogingstemperature tussen 60 en 105ºC.
Lineêre modelle is deur ’n gelyktydige regressie benadering gegrond op die Seemingly Unrelated Regression (SUR) wat ’n“Systemfit” R statistiese pakket gebruik, parameteriseer. Die voorspeller veranderlikes wat in hierdie studie gebruik is, is dbh, d2h en h waarin die koëffisient van bepaling (R2), gemiddelde standaardfout (MSE) en vierkantswortel van die gemiddelde standaardfout (RMSE) gebruik is om vas te stel hoe goed die model pas. Akaike Inligting Kriteria is gebruik vir die seleksie van die gepaste model. ’n Reeks vergelykings wat bestaan uit vyf modelle is vir elke Eucalyptus spesie geformuleer. Die biomassa voorspelling model het waardes vir die koëffisiente van bepaling (R2) opgelewer wat strek van 0.65 to 0.98% en waarin dbh en d2h die hoof voorspelling veranderlikes is, terwyl h die pas van die model verbeter. Die totale biomassa model het in die meeste gevalle die beste gepas en die blaarbiomassa die swakste as dit met die ander modelle vergelyk word. Tydens droging vind die grootste persentasie verandering van 6% by stamhout plaas tussen temperature van 60ºC tot 105ºC, en die kleinste persentasie verandering van minder as 2% by blare.
|
30 |
A spatial approach to edge effect modelling for plantation forestryWise, Andre 12 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: One of the major objectives in plantation
forestry is to
achieve
a
high
level
of
homogeneity
of
distribution
and
dimension
of
trees
within
the
stand.
Precise
planting
geometries,
intensive
silviculture
and
genetic
selection
are
used
to
achieve
this
homogeneity.
However,
a
natural
variability
is
still
introduced
by
micro-‐site
conditions
and
disturbances.
A
substantial
source
of
variation
is
caused
by
edge
effects
of
neighbouring
stands
or
other
land
use
forms.
The
edge
effect
causes
trees
at
the
stand
edge
to
develop
differently
from
trees
in
the
interior
of
the
stand.
The
overarching
objective
of
this
study
is
to
simulate
the
edge
effect
based
on
average
stand
interior
variables
as
typically
received
from
an
enumeration
and
spatial
information
on
the
current
and
historic
stand
neighbourhood.
With
re-‐introducing
this
natural
variance
as
well
as
its
spatial
pattern,
we
expect
to
derive
improved
planning
information.
A
major
aim
is
thus
separating
the
effect
of
the
edge
interaction
from
the
other
factors
contributing
to
stand
variance
and
quantifying
the
result
in
terms
of
stand
output.
A
methodology
is
introduced
for
quantifying
interaction
at
stand
edges
between
a
given
stand
and
its
neighbouring
stands
over
its
lifetime.
Transferring
the
edge
interaction
value
from
the
edges
to
all
the
trees
within
the
stand
is
then
done
by
applying
inverse
distance
weighting
interpolation
from
the
edges
to
the
tree
position
within
the
stand.
Once
an
edge
interaction
value
has
been
calculated
for
each
point,
the
extent
of
the
edge
effect
is
quantified.
The
spatial
extent
of
the
edge
effect
is
derived
empirically
from
an
existing
fully
spatially
mapped
stand
by
means
of
breakpoint
regression.
The
expected
variance
as
a
result
of
edge
influence
is
then
quantified
by
producing
a
set
of
models,
which
can
reproduce
the
effect
of
the
edge
interaction
on
tree
height,
diameter
and
volume.
The
edge
effect
is
treated
as
a
dynamic
interaction
for
which
the
temporal
aspect
needs
to
be
considered,
because
the
current
spatial
structure
of
a
stand
is
influenced
by
its
current
neighbourhood,
but
also
by
the
historic
development
of
the
neighbourhood
in
relation
to
the
stand
in
question.
Each
stand
therefore
undergoes
an
edge
effect
which
is
completely
unique
to
that
stand,
within
a
given
time
period.
For
this
reason
the
presented
methodology
is
a
spatial-‐temporal
one,
aimed
at
providing
a
way
in
which
growth
and
yield
forest
modelling
can
be
augmented
by
the
inclusion
of
the
edge
effect
in
a
practical
way.
To
explicitly
quantify
edge
effects,
the
natural
variance
had
to
be
separated
into
a
component
explained
by
edge
effect
and
a
second
component
introduced
by
other
factors
such
as
micro
site
conditions
and
disturbance.
The
second
component
is
treated
as
an
unexplained
residual
variance.
In
order
to
provide
a
realistic
simulation
of
a
stand
output
at
a
finer,
tree
level,
this
second
stand
variance
needs
nonetheless
to
be
quantified.
The
variance
attributable
to
factors
other
than
the
edge
effect
is
mimicked
by
generating
a
random
number
by
means
of
a
parameterised
stochastic
process
based
on
the
variance
of
the
inner
stand
region,
which
is
beyond
the
reach
of
the
edge
effect.
In
this
way,
a
realistic
spatial
pattern
of
a
plantation
forest
stand,
taking
into
account
the
edge
effect
and
combining
it
with
the
natural
stand
variance
is
achieved.
This
study,
within
the
field
of
plantation
forest
management,
aspires
to
land
use
optimization
both
in
terms
of
productive
capacity
estimation
and
for
the
provision
of
information
for
effective
land
use
management
planning.
It
makes
use
of
open
source
software
resources
namely
the
R
framework
and
QGIS
and
explores
aerial
stereophotogrammetry
as
an
option
for
data
collection. / AFRIKAANSE OPSOMMING: Een
van
die
hoofdoelwitte
in
plantasie
bosbou
praktyk
is
hoё
vlakke
van
homogeniteit
met
betrekking
tot
die
verspreiding
en
die
dimensies
van
die
bome
in
die
plantasie
opstand.
Simetriese
aanplantings,
intensiewe
bosboupraktyk
en
genetiese
seleksie
word
gebruik
om
hierdie
homogeniteit
te
verkry.
Natuurlike
verskille
word
egter
nog
steeds
gevind
as
gevolg
van
groeiplek
mikro
toestande
en
ander
versteurings
in
die
opstand.
Een
van
die
hoofbronne
van
hierdie
variasie
is
die
randeffekte
van
buurplantasies
en
ander
gebruike
van
grond.
Hierdie
randeffekte
veroorsaak
dat
bome
aan
die
rand
van
die
opstand
anders
ontwikkel
as
die
bome
binne
in
die
opstand.
Die
oorhoofse
doelwit
met
hierdie
navorsing
is
om
die
randeffekte
te
simuleer.
Hierdie
randeffekte
is
gegrond
op
die
gemiddelde
binneopstand
boom
veranderlikes
soos
afgelei
uit
die
opmeting
en
uit
ruimtelike
inligting
oor
die
huidige
en
geskiedkundige
toestande
in
die
omgewing.
As
hierdie
natuurlike
variasies
asook
die
ruimtelike
patrone
weer
in
berekening
gebring
word,
verwag
ons
om
beter
beplanningsinligting
te
bekom.
’n
Belangrike
doelwit
tydens
hierdie
navorsing
is
dus
om
die
effek
van
die
rand-‐interaksie
te
skei
van
die
effek
van
ander
faktore
wat
bydra
tot
variasies
binne-‐in
die
opstand
en
om
die
resultaat
in
terme
van
plantasie
produksie
te
kwantifiseer.
’n
Metodiek
word
voorgestel
vir
die
kwantifisering
van
die
interaksie
op
die
rande
tussen
die
opstand
en
die
buuropstande
tydens
die
leeftyd
van
die
opstand.
Die
oorplasing
van
die
rand
interaksie
waarde
van
die
rand
af
na
al
die
bome
in
die
plantasie
word
dan
gedoen
deur
om
geweegde
inverse
afstand
interpolasie
vanaf
die
rand
tot
by
die
ligging
van
die
boom,
toe
te
pas.
As
die
rand
interaksie
waarde
vir
elke
punt
bereken
is,
kan
die
omvang
van
die
randeffek
gekwantifiseer
word.
Die
ruimtelike
omvang
van
die
rand
effek
is,
met
die
gebruik
van
breekpunt
regressie,
empiries
afgelei
van
’n
bestaande
ten
volle
karteerde
plantasie.
Die
verwagte
variasie
as
gevolg
van
die
randeffek
word
dan
met
die
gebruik
van
’n
stel
modelle
gekwantifiseer,
wat
dan
die
effek
van
die
rand
interaksie
op
boomhoogte,
deursnit
en
volume
kan
weergee.
Die
randeffek
word
as
’n
dinamiese
interaksie
beskou
waarvan
die
tydsaspek
in
ag
geneem
moet
word,
want
die
huidige
ruimtelike
struktuur
van
die
plantasie
word
beïnvloed
deur
die
huidige
omgewing
asook
deur
die
historiese
ontwikkeling
van
die
omgewing
met
betrekking
tot
die
opstand
onder
bespreking.
Elke
opstand
ondergaan
’n
randeffek
wat
uniek
is
aan
daardie
plantasie
op
die
gegewe
tydstip.
Die
doelwit
is
om
’n
wyse
te
vind
waarvolgens
groei-‐en-‐opbrengs
plantasie
modellering
deur
die
insluiting
van
randeffek
op
’n
praktiese
wyse,
aangevul
kan
word.
Om
hierdie
rede
is
die
aanbevole
metodiek
ruimtelik-‐tydelik
en
gerig
daarop
om
’n
wyse
te
vind
waarvolgens
groei-‐en-‐opbrengs
modellering
deur
die
insluiting
van
die
randeffek,
op
’n
praktiese
wyse
aangevul
kan
word.
Om
randeffek
eksplisiet
te
kwantifiseer,
moes
die
natuurlike
afwyking
gedeel
word
in
die
komponent
wat
die
gevolg
is
van
die
randeffek,
en
’n
tweede
komponent
wat
die
gevolg
is
van
ander
faktore
soos
mikroligging
toestande
en
versteurings.
Die
tweede
komponent
word
behandel
as
’n
onverklaarde
oorblywende
afwyking.
Hierdie
tweede
plantasie
afwyking
moet
nogtans
kwantifiseer
word
om
sodoende
’n
realistiese
simulasie
van
plantasie
opbrengs
op
’n
fyner
boom
vlak
te
verkry.
Die
afwyking
wat
toegeskryf
kan
word
aan
faktore
buiten
die
randeffek,
word
nageboots
deur
om
’n
lukrake
nommer
(wat
gebaseer
word
op
die
afwyking
van
die
binne-‐plantasie
gebied
wat
buite
die
strekwydte
van
die
randeffek
is)
deur
middel
van
‘n
geparameteriseerde
stogastiese
proses
te
genereer.
Sodoende
word
’n
realistiese
ruimtelike
patroon
van
’n
plantasie
opstand
verkry,
wat
die
randeffek
in
ag
neem
en
dit
kombineer
met
die
natuurlike
plantasie
afwyking.
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