Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 1985. / Die ontstaan van waaisand langs die Suidwes-Kaapse kus en die geskiedenis van waaisandherwinning in die gebied word behandel. Die gebruik van Ammophila arenaria (marram) en A. breviligulata tydens die herwinning van waaisand in ander lande word bespreek. Verskillende metodes kan gebruik word om die resultate van die onderskeie behandelings op die groei van marramgras te bepaal.

Thesis (MSc (Forest and Wood Science))—University of Stellenbosch, 2007. / The present study investigated double sampling with regression estimators as a quest for efficiency and effectiveness in forest inventory in Namibian woodlands. Auxiliary data used were obtained from Standard QuickBird satellite scenes (phase 1) for Hans Kanyinga Community Forest from October and November 2004 covering an area of 12,107 hectares, amplified with terrestric data (phase 2) of 2002. The relationships between auxiliary and terrestric variables are described and prediction models were constructed. According to the results of the stepwise procedure with the Mallow’s Cp statistic as the selection criteria, photogrammetric stand density and a combination of the photogrammetric crown area with photogrammetric stand density were the best candidates for predicting the stand volume. The resulting volume model explains 56% of the variation. Photogrammetric stand density was found to be highly correlated to the terrestric stand density with the resulting model explaining 81% of the variation. Photogrammetric crown diameter was found to be correlated with the diameter at breast height measured from the plots which were assessed for spatial tree positions, which enabled the derivation of the diameter distribution. The diameter distribution model explains 43% of the variation. In addition, the actual tree positions were determined using the GPS and surveying techniques (polar positions) involving distance and bearings. GPS tree positions showed a considerable shift of up to 8.67 m. However, only the distance measurements of tress from the plot centre using the infield surveying methods were more reliable. Nevertheless, the influences of the tree positional errors are not of high concern for temporary based sample plots which are normally used in Namibian forest inventories. A reduction in inventory cost was found to be 24% i.e. N$25.79 to N$19.67 per hectare. The results of this study are valid for Kavango region or any other region with similar set of physical and climatic conditions, but caution must be exercised in implementing these results elsewhere under different physical and environmental conditions.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This thesis assesses the livelihoods of rural households in a proposed green field forestry area, located in Sanga District of Niassa province, Mozambique. The livelihood analysis was used to analyze potential socio-economic impacts of introducing forest plantations to rural households located within the proposed afforestation area. The study made use of household interviews, key informant interviews and secondary data. The sustainable livelihoods framework was used in the research process to develop the household questionnaire and to identify livelihood strategies. Data was analyzed using 331 household questionnaires collected throughout the proposed afforestation area in various communities in the study area. Findings from the study indicated that there is minimal wealth gaps between rural households; but that the introduction of the forestry industry and the subsequent employment created thereof may result in larger wealth gaps between wage earning and non-wage earning households. The study further concludes by linking the potential socio-economic impacts with mitigation recommendations that could be harmonized with FSC Standard requirements for forestry companies interested in developing a forest industry in the study area. / AFRIKAANSE OPSOMMING: Hierdie tesis ontleed die lewensbestaan van landelike huishoudings in ‘n voorgestelde nuwe bosbou area, gelee in die Sanga distrik van die Niassa provinsie, Mosambiek. Die lewensbestaan ontleding was gebruik om die potensiele sosio-ekonomiese impak van die vestiging van bosbou plantasies op landelike huishoudings in die voorgestelde bebossings area te analiseer. Hierdie studie het gebruik gemaak van huishoudelike onderhoude, sleutel informant onderhoude asook sekondere data. Die volhoubare lewensbestaan raamwerk was gebruik in die navorsings proses om die huishoudelike onderhoude te ontwikkel en om die huishoudelike strategiee te identifiseer. Data was geanaliseer van 331 huishoudelike onderhoude afgeneem in verskeie gemeenskappe binne die studie areas. Bevindinge van die studie het aangetoon dat daar minimale inkomste gapings is tussen landelike huishoudings, maar met die vestiging van kommersiele bosbou en geassosieerde werskeppings moontlikhede, mag groter inkomste gapings ontwikkel tussen huishoudings wat inkostes uit bosbou verdien en huishoudings daarsonder. Verder het die studie aangetoon dat daar ‚n potensiele sosiale impak is van mense wat na die area migreer en dat sulke impakte deur FSC sertifisering beheer kan word.

Thesis (MScFor) (Forest and Wood Science)--University of Stellenbosch, 2007. / While the contribution of non-timber forest products (NTFPs) in sustaining livelihoods of the poor is gaining global attention, the importance of woodcarving trade in sustaining the livelihoods of the poor people has been poorly researched. A study was conducted in Cape Town area of the Western Province, South Africa to assess the contribution of woodcarving trade to the livelihoods of the traders and the dynamics of the trade, and institutional constraints impacting on the development of the trade. A total of 61 traders in wood carving, as well as municipal authorities and key informants, were interviewed using structured questionnaires; note taking, personal observations, and in-depth interview based open-ended questions. The findings of the study revealed that the woodcarving trade is a highly male (69%) dominated activity. Most traders were married (55%) and most of the respondents (63%) fell within the active age group of 21-35 years. The wood carving trade was dominated by highly literate people with 66% and 25% having reached secondary and tertiary education, respectively. The study also revealed that “earning a living” represented the single most important factor (70%) that pushed people into the wood carving trade. Most traders (85%) did not own property but for those who owned property, 56% were South Africans followed by Zimbabweans (22%). The study showed that most of the woodcarving products arriving in the Western Cape come from the SADC region accounting for 78% of the products. Malawi (36%), Zimbabwe (30%) and Kenya (13%) are the main sources of the wooden crafts curio into the Western Cape woodcraft market. The study also found that Dalbergia melanoxylon from Zimbabwe (47%) and Malawi (16%) and Brachylaena huillensis from Kenya (47%) and Afzelia quanzensis from Zimbabwe (27%) represent the most traded wood species. The wood for carving was mainly accessed through intermediate agents (48%) and on site purchase (43%); and polishing represented the most important process (80%) of value adding compared to painting and shining. Personal cars (38%) and buses (36%) were the main means of transportation used compared to other forms of transport. It was shown that cost (48%) and customer based price (33%) represented the main pricing methods used by traders. Shop owners had an average income estimated at R 6, 450 and R 2, 692 in good and lean month sales, respectively. In addition, seasonality represented the single most important factor (56%) threatening the woodcarving industry and the livelihood of urban traders compared to factors such as quality of wood product (18%) and scarcity of the resource (10%). This study found that traders had difficulties accessing physical infrastructures (87%); social assets (50%) and human capital (74%). On the other hand, 62% of the traders did not seem to have problems accessing natural assets. As a livelihood strategy, traders also undertook multiple activities including sale of minor products as well as soliciting extra help from companions and/or hiring extra help during peak seasons. For the sustainability of the woodcarving trade in the Western Cape, there is a need for sustained, long-term management of wood species used for carving through domestication and use of alternative wood species. In addition, policies should promote: (i) integrated resource use that will ensure maximum utilisation of the wood from a single tree e.g. timber and wood carving, (ii) the culture of association and cooperation among traders, (iii) collaborative mechanisms involving all players from the forest and the tourism sector as well as the traders, (iv) secure traders’ livelihood assets, (v) an environment favourable to business venture’s expansion and growth through micro-finance and micro-credit schemes.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2007. / This study evaluates the variation that exists between six sites and between more than 200 Pinus patula families established across the sites for various traits utilised in a tree improvement programme. The traits utilised were growth at ages five and eight years, gravimetric densitometry of a sub-sample of the top 100 families at age eight, and microdensitometry and fibre morphological characteristics as determined by image analysis of increment cores, extracted from a sub-sample of the top 30 families. Significant differences were found between locations for growth at ages five and eight, density (both gravimetric and micro densitometry) and fibre properties. For each of the site combinations, utilising Type B- genetic correlations, the interaction between families and locations were evaluated in order to determine which locations could be grouped together in order to determine the effect various sites will have on the deployment of material. Significant differences were also found between families for the various traits investigated, which would indicate that desired trait or trait combinations can be selected for in a tree improvement programme. Heritability estimates for growth varied across sites, ranging from 0,32 to 0,57 at five years and 0,34 to 0,59 at eight years for family heritability. The individual tree estimates ranges from 0,08 to 0,27 at five years and from 0,09 to 0,26 at eight years. The standard errors associated with the heritability estimates for growth however indicate that the estimates, especially those of the individual trees should be used with caution. The heritability estimates for density and fibre morphological characteristics on the family and individual tree level are on a number of sites very high, although this is associated with large standard errors. Indications were that the traits can be combined effectively into a multi-trait selection index, since the phenotypic and genotypic correlations indicated mostly favorable or slight negative correlations between traits.

Thesis (MscFor)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The state owned and managed forest and woodland resources during the colonial and postindependence periods in Mozambique. However, the centralised government forestry policies failed to stop the continual loss of natural forest and woodland resources under the state control. This study is concerned with the sustainability of a cimbirre (Androstachys johnson iidominated) woodland in a rural part of Mozambique. A. johnsonii trees are the major source of subsistence and income generation in southern Mozambique. Nevertheless, the exploitation of the species is running illegally because the diameters used for poles are below the harvestable diameter limit defined by the forestry legislation. This study is part of the research activities of a community-based natural resources management project being implemented in the Mabote District. The study focuses on the four villages covered by this project funded by the Government of Finland. It intends to develop guidelines for sustainable management of the woodland which is of a great concern to the rural woodland-dependent communities. The study examines the socio-economic context of commercial harvesting of A. johnsonii trees for poles by local communities, as well as the sustainability of the woodland resources concerned, especially with respect to the setting of minimum harvestable diameter limits. It is assumed that the current deliberate burning of cimbirre woodlands to kill the desired species would cease once a sustainable diameter limit is established. Three methods are used to respond to the objectives of the study, namely: (1) Semi-structured interviews and group discussions with key informants; (2) Structured questionnaire surveys submitted to households randomly selected within the four villages being studied; and (3) Forest resource assessment. The literature review documents the theoretical issues of sustainable management of natural resources and forest in particular, both past and present. It indicates that a state-community partnership should be considered for sustainable management of the area. It is also valid for communal areas in Mozambique in general, where the government legally controls forest resources. The implementation of the structural adjustment programme that Mozambique currently pursues, allied to the retrenchments in the gold mining industry in South Africa and the abolishment of recruitment of Mozambican labourers in the South African mining industry, have transformed the traditional forms of rural livelihoods. These measures provide rather large incentives for private interests to exploit poles for commercial purposes. Findings of this study based on the forest resource assessment provide an ecological basis for allowing harvesting of juvenile trees of A. johnsonii for poles by local communities, because the current level of harvesting trees does not lead to woodland degradation. Besides, the centralised policies that governed the allocation of forest resources both in colonial and postindependent Mozambique have transformed traditional authorities. This has led to a confusion of roles and conflicting power in forest management. Key words: Community involvement, deforestation, sustainable natural forest management. / AFRIKAANSE OPSOMMING: Gedurende die koloniale en post-onafhanklike periode in Mosambiek is die woude en bosland hulpbronne deur die staat beheer en besit. Dié gesentraliseerde regeringsbeleide het egter nie die voortdurende verlies aan natuurlike hulpbronne onder staatsbeheer gestop nie. Hierdie studie handle oor die volhoubaarheid van 'n cimbirre (Androstachys johnson ii-dominated) inheemse bos in 'n landelike deel van Mosambiek. A. johnsonii bome is die hoofbron van bestaan en inkomstegenerering in die suidelike deel van Mosambiek. Nogtans word dié spesie onwettiglik uitgebuit omdat die deursnee vir pale onder die oesbare minimum deursnee is, soos bepaal deur bosbouwetgewing. Dié studie vorm deel van die navorsingsaktiwiteite van 'n gemeenskapsbeheerde, natuurlike hulpbron bestuursprojek wat tans geïmplementeer word in die Mabote Distrik. Die fokus van dié studie is vier dorpies wat gedek word deur die projek. Die doelwit is om riglyne te ontwikkel vir die volhoubare bestuur van die bosgebied wat 'n groot bron van bekommernis is vir die landelike gemeenskappe wat van die bos afhanklik is. Die studie ondersoek die sosioekonomiese konteks vir die kommersiële oes van A. johnsonii bome vir pale deur die plaaslike gemeenskappe, sowel as die volhoubaarheid van die bosebied se hulpbronne hier betrokke, veral met die oog op die bepaling van 'n minimum deursnee beperking vir oesdoeleindes. Dit word aanvaar dat die huidige doelbewuste brand van cimbirre boslande, om die gewenste spesies dood te maak, beeïndig sal word as 'n volhoubare deursnee limiet vasgestel word. Dit sal gedoen word met behulp van insette deur die afhanklike gemeenskappe. Drie metodes is gebruik om die doelwitte van die studie te behaal; (1) Semigestruktureerde onderhoude en groepbesprekings met kerninformante; (2) Getruktureerde vraelys opname wat aan lukraak geselekteerde huishoudings binne die vier dorpies (wat deel maak van studie) gegee is; en (3) Hulpbronwaardering in die bos. Die literatuurstudie dokumenteer die teoretiese kwessies oor die volhoubare bestuur van natuurlike hulpbronne en dan spesifiek woude, beide in die verlede en in die huidige situasie. Die gevolgtrekking is dat 'n staatgemeenskapsvennootskap oorweeg moet word vir die volhoubare bestuur van die area. Dit geld ook in die algemeen vir die kommunale areas in Mosambiek, waar die regering wettiglik woudhulpbronne beheer. Die implementering van strukturele aanpassings programme tans in Mosambiek, asook die afdankings in die goudmynindustrie in Suid-Afrika en die beeïndiging aan die werwing van Mosambiekse arbeiders deur Suid-Afrika, het tradisionele vorms van landelike broodwinning getransformeer. Dit lei weer tot die misbruik van pale vir kommersiële doeleindes, deur die privaat sektor. Bevindings uit dié studie, gebaseer op die woudhulpbron waarderings, verskaf 'n ekologiese basis vir die oes van jong A. johnsonii bome vir pale deur die plaaslike gemeenskappe, want die huidige vlak van oes van dié bome lei nie tot boslandagteruitgang nie. Boonop het die gesentraliseerde beleide wat die toekenning van woudhulpbronne beheer, in beide 'n koloniale Mosambiek en 'n post-onafhanklike Mosambiek, tradisionele gesagsstrukture getransformeer. Dit het gelei tot 'n verwarring in rolle en 'n konflik in mag in inheemse bosbestuur. Key words: Deforestasie, gemeenskapsbetrokkenheid, volhoubare natuurlike bosbestuur.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The aim of the study was to extract elevation information (such as tree height) from stereo satellite imagery (IRS-I C), to scrutinise the performance of the DTM (Digital Terrain Model) tools as provided by the LH (LeicalHelava) Systems' softcopy system, and subsequently to perform a feasibility study on the application of a practically viable forest inventory design. A softcopy photogrammetry workstation (LH Systems DPW 770), IRS-I C stereo panchromatic satellite imagery, and digital aerial photography at a scale of 1:30000 (scanned at 15 micrometers) was used. The study was conducted over various sites in the Sabie area (province of Mpumalanga) in South Africa, where extensive man made forests with pine and eucalypts are to be found. The extraction of stand parameters such as tree height was performed manually, semi-automatically, and automatically. In addition, the compartment area was determined using a GIS tool. The Digital Surface Models (DSM), representing the canopy structure of the stands, was extracted from the IRS-I C imagery and validated through a comparison of the resulting contours with the corresponding contours generated by aerial photogrammetric methods. Due to the coarse spatial resolution of the IRS-IC imagery (5m) and the suboptimal BIH (BaselHeight) ratio (0.57), only objects featuring a height exceeding 20m could be manually measured with confidence. Furthermore, only the edges of the compartments proved to be suitable for the determination of tree heights (i.e. with a sufficiently large parallax difference and image contrast). The manual determination of tree heights in the IRS-I C imagery yielded accuracies of about 95% compared to the height values of the aerial photographs and the ground data. The application of image enhancement techniques had severe effects on the accuracy of the IRS-IC stereo model, resulting in deviations of about -57m from the 'true' value. It was observed that image matching was only a problem where features changed their appearance (e.g. clearfelled or burnt areas) during the acquisition period of the stereo pair of the satellite imagery. LH Systems' Adaptive Automatic Terrain Extraction (AATE) tool performed very well for the creation of digital terrain and surface models when using digital aerial photography with a high scanning rate. In contrast, the automatic creation of canopy surface models from various forest compartments did not yield any useful results when applied to IRS-l C imagery. AATE could not model the canopy structure properly. The coarse spatial resolution of the satellite imagery in conjunction with the sparse post spacing (20m) and matching errors are most likely to be responsible for this poor performance. Two-phase sampling and the Hugershoff method were chosen for automatically derived height values to be evaluated for possible application in forest inventory. Unfortunately, neither for the determination of the regression estimator for the first method, nor for the calculation of timber volume after application of the Hugershoff method could any useful result be obtained. This is mostly due to the fact that image matching errors and blunders (resulting in tree heights of -885m) were not properly accounted for in the terrain extraction software. However, the outcomes for the manual measurement of tree heights performed on the satellite imagery show that under optimal conditions accuracies can be achieved similar to those for the height determination in small scale aerial photographs, but at lower cost. The obtained height values can then be used for the calculation of timber volume according to Eichhorn's law. Keywords: AATE, blunders, digital photogrammetry, DPW770, forest inventory, Hugershoff IRS-l C, matching error, remote sensing, satellite imagery, two-phase sampling / AFRIKAANSE OPSOMMING: N GANGBAARHEIDSTIIDIE VIR BOSINVENTARIS MET BEHULP VAN STEREO SATELLIETBEELDE MET GEBRUIK VAN SAGTEKOPIE FOTOGRAMMETRIESETEGNOLOGIE: Die doel van hierdie studie was om elevasie inligting (soos boomhoogtes) uit stereo satellietbeelde (IRS-I C) te ontrek, en die DTM (Digitale Terrein Modelle) funksies van die LH Systems se sagtekopie sisteem te evalueer en 'n ondersoek in te stel na praktiese toepassing van die tegnologie in bosvoorraadopname. 'n Sagtekopie fotogrammetriese werkstasie (LH Systems DPW 770), IRS-I C stereo panchromatiese satellietwaarneming en digitale lugfotografie is gebruik. Die studie is uitgevoer oor verskeie areas in die Sabie omgewing (Mpumalanga, Suid-Afrika), waar daar ekstensiewe mensgemaakte woude voorkom met denne en Eucalyptus soorte. Die ekstraksie van opstandparameters soos boomhoogte is uitgevoer met die hand, as ook met semi-outomatiese en outomatiese metodes. Die digitale oppervlakmodelle (wat die kroondakstrukture van die opstande voorstel) was vanaf die IRS-I C beelde onttrek en gevalideer deur vergelyking van die resulterende kontoere met die korresponderende kontoere wat deur lugfotogrammetriese metodes gegenereer is. As gevolg van die growwe ruimtelike resolusie van die IRS-IC waarneming (Sm) en die suboptimale BIH verhouding (0.57) kan slegs voorwerpe met 'n hoogte van meer as 20m met vertroue met die hand gemeet word. Slegs die rande van die vakke is bruikbaar vir die berekening van boomhoogtes (d.w. s. met 'n voldoende paralaksverskil en 'n sterk beeldkontras ). Boomhoogtes wat met die hand bepaal is vanaf IRS-I C beelde is 95% akkuraat in vergelyking met die hoogtewaardes verkry vanaf die lugfoto's en die veldmetings. Die toepassing van beeldverbeteringstegnieke het duidelike invloede op die akkuraatheid van die IRS-IC stereomodel met afwykings van ongeveer -57m vanaf die "werklike" waardes. Daar is ook waargeneem dat beeldooreenstemming slegs 'n probleem is waar terreinvorme se voorkoms verander het (weens afkappings of brande) gedurende die verkrygingsperiode waarin die stereo paar van die satellietbeelde verkry is. LH Systems se Aanpassende Outomatiese Terrein Onttrekkings (Adaptive Automatic Terrain Extraction - AATE) instrument het goed gevaar tydens die gebruik van digitale lugfotografie met Inhoë skanderingstempo. In kontras hiermee het die outomatiese skepping van kroondakoppervlakmodelle van verskeie plantasievakke geen nuttige resultate gelewer wanneer dit op IRS-I C beelde toegepas is nie. Die growwe ruimtelike resolusie van die satellietbeelde tesame met die wye paalspasïering (20m) en passingsfoute is waarskynlik vir hierdie swak resultate verantwoordelik. Twee-fase proefueming en die Hugershoff metode was gebruik vir die bepaling van outomaties afgeleide hoogtewaardes vir evaluering van moonlike toepassing in bosvoorraadopnames. Geen bruikbare resultate kon verkry word vir die vasstelling van die regressieskatter vir die eersgenoemde metode of vir die berekening van die houtvolume volgens die Hugershoff metode nie. Dit is meestal as gevolg van beeld-- ooreenkomsfoute en flaters, (wat tot boomhoogtes van -885m gelei het) wat nie voldoende in ag geneem word in die terreinekstraksie sagteware nie. Die resultate vir die handgemete ('manual') boomhoogtebepaling wat uitgevoer is op die satellietbeelde (op die sagtekopie werkstasie DPW 770), toon dat akkuraathede soortgelyk aan daardie vir hoogte bepaal op klein-skaal lugfotos onder optimale toestande verkry kan word, maar goedkoper. Die hoogtewaardes wat verkry is kan gebruik word vir die berekening van houtvolume volgens die wet van Eichhorn. Sleutelwoorde: AATE, afstandswaarneming, bosvoorraadopnames, digitale fotogrammetrie, DPW770, flaters, Hugershoff, IRS-! C, satellietbeelde, twee-fase proefueming

Thesis (MScFor)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The windbreak species near Wolseley (WoSl and WoS3) was Casuarina cunninghamiana. The windbreak species near Saron (SaSl) and Villiersdorp (ViSl) was Eucalyptus cladocalyx and Pinus radiata respectively. A shelter effect was indicated at ViSI (from northerly winds in winter/early spring 1999), and WoS3 (from southerly winds in late spring 1999). Wind speeds were consistently reduced in the leeward sheltered zone ofViSl and WoS3. To improve the correlation of the shelter effect, mild contaminating winds (comprising approximately 28% of the total data recorded at each site) were excluded for the prediction equations of the shelter effect at each site. Compared to the more exposed wind speeds at 1.0 H to the windward side, wind speeds at ViS] were reduced by 32% at 3.0 H. Compared to 11.0 H, wind speeds at ViSl were reduced by 49 and 46% at 3.0 and 1.0 H respectively. With r2 values above 93%, accurate linear prediction equations were produced. The early barley damage assessments indicated that damage was absent or negligible at 11.1 H to the lee, and significantly highest (X < 0.05) at 13.7 H to the lee and beyond. The crop shelter effect significantly increased (p < 0.05) barley head number, transformed proportion of total barley head mass from above-ground mass, potato tuber mass, potato above-ground mass total potato tuber number, small tuber number, and disproportionate tissue damage to the windward section of each plant. For WoS3, the shelter effect became pronounced with severe south-easterly winds. The average hourly wind speeds at 3.0 H dropped from 0.9 m / s (in the previous and less windy sampling period) to 0.8 m / s, despite the sharp increase in exposed wind speeds. Compared to 13.0 H, wind speeds were reduced by 73 and 32% at 3.0 and 7.0 H respectively. With r2 values above 94%, accurate linear prediction equations were produced. The crop shelter effect significantly increased (p < 0.05) sub-sample mass of lOO grains. At WoS3, strong and sustained wind speeds caused leeward soil temperature increases of up to 4°C at 3.0 H, compared to 11.0 H. Brief strong winds (characteristic of winds at ViSl) had little effect on the soil temperature differences. At ViSl, a deviation of soil moisture content between 3.0 and 11.0 H, following periods of recharge, indicated a potential soil-moisture conservation effect in the sheltered zone. This did not occur at WoS3, due partly to a very low soil moisture content that had little scope for variation; From the crop variations and the microclimate variations at both ViS 1 and WoS3, the maximum shelter effect extended to approximately 4.0 H, followed by an intermediate zone of diminishing shelter that extended to approximately 9.0 H. For ViSl, WoS3 and SaSl, a shading effect significantly reduced yields (p<0.05) at 1.0 H from the respective northern windbreak, compared to yields at 2.0 H. At ViS 1 and WoS3, soil probes did not indicate a depletion of soil moisture resulting from the respective windbreaks. Soil moisture competition was indicated on the northern side of the WoSl windbreak with drier conditions; where soil moisture levels at 1.0 and 3.0 H diverged from a negligible level to a 22% lower level (p > 0.05) at 1.0 H, compared to 3.0H. / AFRIKAANSE OPSOMMING: Die boomsoorte wat as windbreke gedien het was Casuarina cunninghamiana naby Wolseley (WoS 1 en WoS3), en Eucalyptus cladocalyx en Pinus radiata by Saron (SaS 1) en Villiersdorp (ViS 1) respektiewelik. Beskutting is aangetoon by ViS 1 (teen noordelike winde in winter/vroee lente 1999) en WoS3 (teen suidelike winde in laat lente 1999). Windspoed is konsekwent aan die lykant sones van ViS 1 en WoS3 verminder. Ten dien einde die korrelasie van die beskuttings effek te verbeter, is matige kontaminerende winde (ongeveer 28% van die totale waargenome data by elke plek) buite berekening gelaat vir die voorspellingsvergelykings van die beskuttingseffek. In vergelyking met die meer blootgestelde windspoede by 1.0 H aan die windkant, is windspoede by ViSl met 32% verminder by 3.0 H. In vergelyking met 11.0 H is windspoede by ViSl met 49 en 46% by 3.0 en 1.0 H respektiewelik verminder. Met r2 waardes hoer as 93%, is akkurate lineere voorspellingsvergelykings verkry. Die vroee gars skade opnames het aangetoon dat geen of minimale skade by 11.1 H aan die lykant aangerig is, en beduidend die hoogste (x< 0.05) by 13.7 Hen verder aan die lykant was. Die gewas beskuttins effek het beduidende toenames (p< 0.05) in garsare, getransformeerde verhouding van totale gars-are massa van bo-grondse massa, aartappelknol massa, aartappel bo-grondse massa, totale aantal aartappeiknolle, en oneweredige weefsel beskadiging aan die windkant van elke plant tot gevolg gehad. Vir WoS3 het die beskuttingseffek beduidend geword met baie sterk suidoostelike winde. Die gemiddelde uurlike windsnelhede by 3.0 H het van 0.9/ (in die vorige en minder winderige toetstydperk) tot 0.8 m/" verminder, ten spyte van die skerp toename in blootgestelde windsnelhede. In vergelyking met 13.0 H is windsnelhede met 73 en 32% by 3.0 en 7.0 H respektiewelik verrninder. Met r2 waardes hoer as 94% 15 akkurate lineere voorspellingsvergelykings verkry. Die gewas beskuttingseffek het sub-monster massa van 100 graankorrels beduidend (p< 0.05) verbeter. By WoS3 het sterk en volgehoue windsnelhede grondtemperature aan die lykant met tot 4°C by 3.0 H verhoog in vergelyking met 11.0 H. Kortstondige sterk winde (tipiese winde by ViS1) het weinig uitwerking op grondtemperatuursverskille gehad. By ViS1 het 'n afwyking van grondwaterinhoud tussen 3.0 en 11.0 H na tydperke van aanvulling, 'n potensiele grondwaterbewaringseffek in die beskutte gebied getoon. Soortgelyke tendense het nie by WoS3 voorgekom nie, gedeeltelik as gevolg van 'n baie lae grondwater inhoud wat nie veel kon varieer nie. Van die variasies wat in gewasse en mikroklimaat voorgekom het, by beide ViSl en WoS3, kan afgelei word dat maksimum beskutting tot by ongeveer 4.0 H verleen is, gevolg deur 'n intermediere sone van verminderende beskutting tot ongeveer 9.0 H. Vir ViS1, WoS3 en SaSl het 'n skadu-effek gewasopbrengs beduidend (p< 0.05) by 1.0 H verminder in vergelyking met opbrengste by 2.0 H. By ViS 1 en WoS3 het grondwater strooiingspeilers nie 'n uitputting van grondwater as gevolg van die windbreke getoon nie. Kompetisie vir grondwater is getoon aan die noordelike kant van die WoS1 windbreek met droer toestande. Grondwatervlakke by 3.0 H het minimaal maar by 1.0 H met 22% beduidend (p> 0.05) teenoor 3.0 H gedaal.

Thesis (MScFor)--Stellenbosch University 2001. / ENGLISH ABSTRACT: Ackerman PA. 2001. An Investigation into the Shorthaul Transport of Pulpwood in South Africa. M.Sc. in Forestry thesis. University of Stellenbosch. 178 pp Shorthaul transport also known as secondary intermediate transport (SIT), a unique feature of pulpwood transport in South Africa, is an additional transport phase within traditional secondary transport. SIT originates at a roadside landing or depot and terminates at another depot, rail siding or merchandising area (not the final destination). The reason for the addition of SIT into the transport chain is identified as the steady decline of forest road conditions to the extent that highway vehicles are unable to reach roadside landings, necessitating the use of intermediate storage sites, from where the timber is once again loaded and transported to final destination. An industry survey established that the decline of forest road conditions are related to excessively high road densities, insufficient funding for road maintenance/upgrading and the lack of understanding by landowners of the importance of maintaining forest road infrastructure. Total funding, by pulpwood companies on roads have shown an increase of R18.55 million from 1997 to 2000, however, subsequent surveys have indicated, that despite this increase in funding, the forest road conditions continue deteriorating. Of the total annual pulpwood intake of 9.39 million tonnes for 1998, 3.7 million tonnes are subject to SIT. Of this 3.7 million tonnes, 2.5 million tonnes are transported from stump to depot and 1.2 million tonnes are transported from landing to depot. The survey identified the agricultural tractor and semi-trailer as the most favoured transport system between stump or landing and depot, responsible for transporting 2.22 million tonnes annually. For 1998, manual loading and three wheel log loaders accounted for the loading of 0.6 and 2.1 million tonnes respectively of the 3.7 million tonnes subject to SIT. This survey information, assisted by newly developed terminology, was used to develop transport scenarios for the economic analysis of total cost of the different transport phases. A network analysis model and pixel-based geographic information system (GIS) were combined to analyse the various transport scenarios within three study areas in the KwaZulu/Natal Midlands, employing SIT on poor, high-density road networks. The simple pixel-based GIS contained information on the forest road network, surface cover and slopes. The results of the economic analysis highlighted the need for the reduction of road network density and for the improvement of the remaining network. This would eliminate the need for extended primary transport and allow the use of highway vehicles transporting from the compartment roadside to and past plantation exits. Results show an average annual cost penalty to the industry, by maintaining SIT, to be R43.25 million or R8.24/m3 . By not employing SIT the industry will potentially save R4.60 for every tonne of the 9.4 million tonnes consumed by the pulpwood processing plants during 1998. Key words: Network analysis. Pixel-based GIS. Timber transport. Secondary transport. Secondary intermediate transport. Secondary terminal transport. Extended primary transport. Primary transport. Dirichlet tessellations. Shorthaul. Note: Throughout this document a full stop (.) is used as a decimal separator. / AFRIKAANSE OPSOMMING: Ackerman PA. 2001.'n Ondersoek na die kortafstand vervoer van pulphout in Suid- Afrika. MSc in Bosbou tesis. Universiteit van Stellenbosch. 178 pp. sekondere intermediere vervoer (SIV), 'n addisionele vervoer-fase binne tradisionele sekondere houtvervoer, is 'n unieke kenmerk van pulphout vervoer in Suid-Afrika. SIV begin op pad, by 'n spesifieke vak of depot en eindig by 'n ander depot, syspoor of verwerkingsgebied (nie die finale bestemming nie). Aangesien die toestand van bospaaie toenemend verswak en omdat swaarpadvervoer nie langer vakke kan bereik nie, word vervoerkontrakteurs al hoe meer gedwing om van depots gebruik te maak waarheen hout deur middel van SIV vervoer moet word. Die hout word dan weer daar gelaai en na 'n verwerkingsfabriek vervoer deur middel van swaarpadvervoer. 'n Landwye opname het getoon dat die swak toestand van bospaaie toegeskryf kan word aan oormatige paddigthede, onvoldoende befondsing vir die instandhouding/ opgradering van paaie en 'n gebrek aan begrip vir die belangrikheid van die onderhoud van pad infrastruktuu r. Die totale kostes aan padverbeterings en opgraderings in die pulphout bedryf, het van 1997 tot 2000 met R18.55 miljoen toegeneem. Verdere opnames toon egter dat ten spyte van hierdie verhoging in befondsing, die toestand van bospaaie steeds onbevredigend is. Van die totale jaarlikse pulphout inname van 9.39 miljoen ton gedurende 1998, word 3.7 miljoen ton aan SIV blootgestel. Van die volume word 2.5 en 1.2 miljoen ton onderskeidelik vanaf die stomp en pad na depots vervoer. Die opname het ook landboutrekkers met leunwaens ge·identifiseer as die gewildste houtvervoer middel tussen die stomp/pad en depots. Hande-arbeid en driewielbloklaaiers is op hulle beurt verantwoordelik vir die laai van onderskeidelik 0.6 en 2.1 miljoen ton pulphout wat deur middel van SIV vervoer word. Inligting uit die opname ondersteun deur nuutgeskepte vakterminologie, is gebruik om verskillende vervoersisteme vir die ekonomiese analise van totale koste van die verskillende vervoerfases te bereken. 'n Netwerk analise model en pixel gebaseerde GIS is in kombinasie gebruik om verskillende vervoer scenarios in drie areas in Kwa-Zulu Natal te ontleed, wat gebruik maak van SIV op swak bospaaie met hoenetwerkdigthede. Die eenvoudige pixel-gebaseerde GIS het inligting weergegee oor bospadnetwerke, oppervlakbedekking en hellings. Die behoefte aan die vermindering van paddigtheid en die verbetering van bospaaie as sulks, is deur die resultate van die ekonomiese ontleding na vore gebring. Dit sal die behoefte vir uitgebreide primers vervoer uitskakel en die gebruik van tradisionele swaar padvoertuie moontlik maak. Die resultate van hierdie opname toon dat die bedryf addisioneel gemiddeld R43.25 miljoen/jaar of R8.24/m3 betaal vir die 3.7 miljoen ton wat onderhewig is aan SIV. Vir die totale 9.4 miljoen m3 het SIV die maatskappye gedurende 1998 R4.60 meer gekos vir elke m3 wat vervoer was. Sleutelwoorde: Netwerkanalise. Houtvervoer. Sekondere vervoer. sekondere intermediere verveer. Sekondere terminale vervoer. VerJengde prirnere vervoer. Kortafstand vervoer. Pixel-gebaseerde GIS Nota: In hierdie document word deurgans 'n punt (.) gebruik om desimale van heelgetalle te skei.

Thesis (MScFor)--Stellenbosch University 2002. / ENGLISH ABSTRACT: One of the greatest .limitations to the productivity of a plantation forest is poor nutrient status of the soil. Empirical application of corrective treatments are marginally successful in some cases, but because of limited understanding of the soiltree system, most nutritional problems go unnoticed or are accepted as a conceivable growth constraint. The aim of this investigation was to identify nutrient growth problems through field observations and to determine means of confirming these nutrient imbalances. Poor and abnormal growth of pine trees in the following areas were investigated: (i) The North Eastern Cape: Ugie and Maclear Districts (ii) The Natal Midlands: Mooi River area (iii) Mpumalanga: .Graskop and Kaapsche Hoop areas (iv) Southwestern Cape: Jonkershoek Plantation The study was conducted as nursery trials at the University of Stellenbosch and field trials at the various locations. Soils from the different regions were collected and used as growing media to test the growth response of five timber species (Pinus patula, P. elliottii, P. taeda, P. greggii and Eucalyptus nitens) under controlled conditions to various nutrient treatments. Indicator plants (cauliflower and soya) were included in these bio-assays. In the field trials nutrients were applied to seedlings and established stands of various ages by means of foliar and soil application. In the nursery trials and the trials where seedlings were planted in the field, plant performance was measured by quantitative means. The reaction of established stands to nutrient treatments were however less vigorous and qualitative means (e.g. colour changes) were used for assessment. Field observations in the North Eastern Cape and the Natal Midlands indicated possible boron, iron and molybdenum deficiencies and thus the work concentrates on these elements. Foliar and soil analyses reinforced these observations with marginal to deficient levels for boron and molybdenum being detected. The yellowing of foliage during the dry season was symptomatic of ineffective nitrogen assimilation and pointed to a molybdenum deficiency while seasonal growth tip dieback, resm exudation, sinuous tree limbs and bushy trees were classical boron deficiency symptoms. Potted trials indicated positive reaction to the application of boron and molybdenum deficiency symptoms were observed on indicator plants. Conclusive evidence of a boron deficiency in some of the pot trials, the planted field trials and the tree evaluation field trials remain elusive due to toxicity experienced as a result of an over-application of the nutrient. The occurrence of multiple deficiencies (phosphorous and calcium) further complicated the findings. The Mpumalanga observations indicated severe nutrient imbalance due to manganese toxicity (strong iron antagonism). The discolouring of the foliage on some sites towards the end of the winter was thought to be an induced molybdenum deficiency on the weathered and acidic red soils. Positive reaction to molybdenum application occurred in a single. tree evaluation trial, but because of soil oxidisation during collection, the effect of manganese toxicity was diluted in the pot trials. Foliar analyses indicated that foliar application of iron was unsuccessful and that other means should be considered to ensure uptake of this nutrient. / AFRIKAANSE OPSOMMING: Die lae vrugbaarheid van grond is een van die grootste beperkings tot die produktiwiteit van plantasie bosbou. Empiriese toedienings van kunsmisstowwe is in sekere gevalle suksesvol tot die bekamping van onvrugbaarheid. Weens gebrekkige kennis t.o.v die grond-boom sisteem word baie van die voedingstof probleme egter onkundig oorgeslaan' of word dit as natuurlike beperking in die produksie konteks aanvaar. Die doel van hierdie ondersoek was om swak boomgroei in die veld waar te neem en om bevestigende metodes te vind waarmee hierdie probleme as voedingstoftekorte geëien kan word. Swak en abnormale boomgroei van denne is in die volgende gebiede ondersoek: (i) Die Noordoos Kaap: Ugie- en Maclear Distrikte (ii) Die Natal Middelande: Mooirivier area (iii) Mpumalanga: Graskop- en Kaapsche Hoop areas (iv) Suidwes Kaap: Jonkershoek Plantasie Die ondersoek is uitgevoer as kwekery proewe by die Universiteit van Stellenbosch en as veldproewe in die onderskeie areas. Grond is uit die verskilende gebiede versamel en as groeimeduim gebruik om die groei-reaksie van vyf verskillende houtspesies (Pinus patula, P. elliottii, P. taeda, P. greggii en Eucalyptus nitens) onder beheerde klimaatsomstandighede te ondersoek. Daar is ook gebruik gemaak van indikator spesies (blomkool en soya) vir diagnose van visuele tekort simptome. Beide saailinge en reeds gevestigde bome is in die veldproewe gebruik. Voedingstowwe is by aanplanting toegedien, of in die geval van groter bome, as blaar- of grondtoedienings. Waar dit moontlik was (meestal in die geval van die saailinge) is die reaksie op die toegediende voedingstowwe met kwantitatiewe metodes bepaal. Daar moes egter van alternatiewe kwalitatiewe metodes gebruik gemaak word om die reaksie by die ouer en groter bome te bepaal. Gevolglik is verandering in bladkleur t.o.v. 'n basiskleur onder andere as maatstaf gebruik. Waarnemings van swak boomgroei in die Noordoos Kaap en die Natal Middelande het gedui op moontlike boor, yster en/of molibdeen tekorte. Lae vlakke van hierdie elemente in blaar- en grondanalises het hierdie waarnemings bevestig. Die geel verkleuring van die naalde gedurende die droë seisoen is simptomaties van oneffektiewe stikstof assimilasie en dui op 'n molibdeen tekort. Die waarneming van seisoenale terugsterwing van groeipunte, gebuigde stamme en takke, gomuitskeiding en bome met bosagtige voorkoms is eienskappe van 'n boor tekort. In die potproewe was daar positiewe reaksie op die toediening van boor en tekort simptome van molibdeen is in die indikator plante waargeneem. In van die potproewe, die saailing veldproewe en ander veldproewe kon daar egter nie uitsluitsel tot die effektiwiteit van boor gevind word nie aangesien toedienings te heftig was en toksisiteit ervaar is. Diagnose van enkel element voedingstof tekorte word bemoeilik deur van die proewe wat ook dui op veelvoudige voedingstoftekorte (veral fosfaat en kalsium). In Mpumalanga is daar waargeneem dat drastiese voedingstof wanbalanse a.g.v. mangaan toksisiteit aanwesig is (veral 'n sterk Fe antagonisme). Die bladverkleuring op sekere proefopstande aan die einde van die winter is ook 'n aanduiding van geïnduseerde molibdeen tekorte wat op die verweerde en suur rooi gronde van die omgewing verwag kan word. Daar was dan ook positiewe reaksie op die toediening van molibdeen, hoewel slegs byeen proefopstand. Die inherente nadeel van potproewe is op die mangaanryk gronde geopenbaar deurdat belugting (gedurende grond versameling) die effek van mangaan toksisiteit verminder het. Die gebruik van blaaranalises is ook voordelig aangewend om te bepaal dat die toediening van yster as blaartoediening onsuksesvol was en dat ander metodes ondersoek moet word om opname van die element te verseker.