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Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The sandy soils of the Riverlands Nature Reserve, near Malmesbury, and the neighbouring farm were studied to determine the effects of long term invasion of the legume Acacia saligna on the soil nutrient content of a soil previously vegetated with fynbos. The effect of the removal of this alien legume on general soil properties and groundwater quality were also studied. The changes in nitrates and nitrites (NOX) due to the invasion and removal of the alien legume were investigated in more detail than changes in other soil nutrients. In addition to that emphasis was placed on the effect of vegetation clearing on groundwater quality, specifically relating to potential contamination with nitrates. This study was initiated after Conrad et al., (1999) found increased NOX concentrations in ground water while studying the effects of pig farming on ground water nitrogen (N) near a site cleared of Acacia saligna by Working for Water (WFW). Since many sites are scheduled for removal of this alien vegetation it was deemed necessary to study the effects that clearing alone had on groundwater quality. It was suspected that there would be an increase in soil and groundwater NOX with vegetation removal due to the inputs from the legume alien invader. Soil sampling was done continuously throughout the rainy season of 2007 (From May to December) on three adjacent sites separated by some 50 m of distance, consisting of a natural fynbos site and two Acacia saligna sites. The sites were selected approximately on the same contour line to prevent interaction through lateral water flow. One of the Acacia sites was cleared by the Working for Water programme in the usual manner leaving slash on the ground. Soil samples were collected at regular intervals throughout the season from all three sites (fynbos, Acacia and cleared site) using a Jarrett soil auger. They were airdried (to achieve full oxidation of mineral N) and sieved though a 2mm sieve. Soils were analysed by atomic absorption spectroscopy for basic cations and by ion chromatography for anions, including nitrates and nitrites. Total carbon and nitrogen was determined by combustion, pH (1M KCl and H2O) and EC (1:5 H2O) were also measured. The present study was part of a wider investigation into the quality of groundwater, modelling flow and contaminant transport (Jovanovic et al., 2008). The largest changes in soil properties were observed in the top (0-5 cm) layer. The fynbos site had a lower nutrient status by comparison to the Acacia site and the cleared site. The sum of cations from the soils of the fynbos site at a soil depth of 0-5cm was 100mg/kg and soils from the cleared and Acacia sites were about 190mg/kg. The Acacia site had a higher NOX status and experienced a larger NOX fluctuation during the rainy season than the fynbos site; minimum NOX values were similar (below 10mg/kg) but the Acacia site had a maximum NOX value of near 60mg/kg and the fynbos site just below 30mg/kg. There was little difference in general soil characteristics (exchangeable cations, pH and EC, total soil C and N) during the first season after clearing, between the Acacia and the cleared sites. The effect of soluble nitrogen changes due to alien legume invasion and removal on groundwater quality, relating to NOX, during the first season after clearing, was determined. It was found that the Acacia site had higher NOX concentrations than the fynbos site. At 0-5cm the fynbos site NOX was less than 30mg/kg and the Acacia site was between 30 and 110mg/kg for most of the season, with values lower than 30mg/kg for the last four sampling dates only. N concentrations on the cleared site behaved in a similar manner to the uncleared Acacia site, but generally N values were lower on the cleared site, there were only two sampling dates where the cleared site had higher NOX values than the Acacia site at 0-5cm. The average groundwater N in NOX under the cleared site was 4.34 mg/l, and under the Acacia site 3.78mg/l, these values are both below the level determined for water contamination with nitrates. However, the increase in ground water nitrate levels after A. saligna clearing was significant. It was concluded that there is a change in the nutrient status of soil with Acacia invasion and again with removal. NOX migrates to the groundwater to a larger degree once vegetation has been removed, although during this study the nitrate pollution threshold of 10 mg/l nitrate N was not reached. / AFRIKAANSE OPSOMMING: Die sanderige gronde van die Riverlands Natuur Reservaat, naby Malmesbury, en die aangrensende plaas was bestudeer om die effek van die langtermyn indringing van die peulgewas, Acacia saligna, op die voedingswaarde van ‘n voorheen fynbos begroeide grond, sowel as die effek van die verwydering van die indringer op die algemene samestelling van die grond en grondwater kwaliteit. Oplosbare stikstof veranderings (NOX) wat plaasvind as gevolg van die indringing en verwydering van die indringer peulgewas, was in meer diepte bestudeer as die ander elemente. Klem was ook geplaas op die effek van die verwydering van plantegroei op grondwater kwaliteit, met spesifieke verwysing na potensiële nitraat besoedeling. Die studie was beplan na Conrad et al., (1999) ‘n toename van NOX konsentrasies in grondwater ontdek het, tydens ‘n studie van die effek wat vark boerdery het op grondwater N naby ‘n area waar Acacia Saligna verwyder was deur Working For Water (WFW). As gevolg van die feit dat verskeie areas in die proses is om skoongemaak te word van Acacia Saligna, is dit nodig geag om die effek daarvan of grondwater kwaliteit te ondersoek. Die hipotesis was dat daar ‘n toename in NOX konsentrasies in grond en grondwater sal wees as gevolg van die verwydering van plantegroei. Grond monsters was deurlopend geneem gedurende die reën seisoen van 2007 (Vanaf Mei tot Desember) uit nabygeleë areas wat omtrent 50 meter uitmekaar is. Die volgende tipes grond was verteenwoordig: ‘n Fynbos begroeide grond sowel as ‘n grond begroei met Acacia saligna. Die areas was geselekteer ongeveer op die selfde kontoer lyn om interaksie tussen areas te voorkom as gevolg van laterale water vloei. ’n Gedeelte van die A. saligna area was skoongemaak deur die Working for Water program op die gewone manier deur die afgesnyde plant materiaal op die grond te los. Grond monster was geneem met gereelde intervalle gedurende die seisoen op al drie areas (fynbos, A. saligna, en skoongemaakte area) deur die gebruik van ’n Jarret grondboor. Die monsters was lugdroog gemaak (om volle oksidasie van die mineraal N te verseker) en toe gesif deur ‘n 2mm sif. Die gronde was analiseer deur atoom absorpsie vir basiese katione en deur ioon chromatografie vir anione, insluitende nitriete en nitrate. Totale koolstof en stikstof was bepaal deur verbranding terwyl pH (1M KCl en H2O) en EC (1:5 H2O) ook gemeet was. Hierdie studie was deel van ‘n wyer ondersoek na die kwaliteit van grondwater, vloei modelering en vervoer van kontaminante (Jovanovic et al., 2008). Die grootste veranderinge in die grond eienskappe was in die boonste grondlaag (0-5cm) waargeneem. Die bevinding was dat die fynbos area ‘n laer voedingswaarde het as die area begroei met die indringer sowel as die die skoongemaakte area. Die som van katione onder fynbos grond by ‘n grond diepte van 0-5cm, was 100/mg/kg en die som van katione by die ander twee areas was omtrent 190mg/kg. Die Acacia area het ‘n hoër NOX inhoud en het ‘n groter NOX fluktuasie ervaar gedurende die reën seisoen as die fynbos area. Die minimum NOX waardes was soortgelyk (minder as 10/mg/kg), maar die Acacia area het ‘n maksimum NOX waarde van omtrent 60mg/kg terwyl die fynbos area se maksimum net minder as 30mg/kg gehad het. Daar nie veel verskil tussen die algemene grond eienskappe (uitruilbare katione, pH en EC, totale C en N) van die Acacia en skoongemaakte areas gedurende die eerste seisoen na die indringer verwyder is nie. Die effek van oplosbare stikstof veranderings as gevolg van die peulgewas se indringing en verwydering op grondwater kwaliteit, met verwysing na NOX, gedurende die eerste seisoen na verwydering van die indringer was bepaal. Dit was bevind dat die Acacia area ‘n hoër NOX konsentrasie as die fynbos area het. Op ‘n diepte van 0-5cm was die fynbos NOX laer as 30mg/kg terwyl die Acacia area tussen 30 en 110mg/kg vir die grootste gedeelte van die seisoen was met waardes laer as 30mg/kg vir die laaste vier datums waarop monsters geneem was. Veranderings in N op die skoongemaakte area en die Acacia area was soortgelyk, maar oor die algemeen was N waardes laer op die skoongemaakte area. Daar was slegs op twee datums gevalle gevind waar die skoongemaakte area ‘n hoër NOX inhoud as die Acacia area gehad het by ‘n diepte van 0-5cm. Die gemiddelde N in NOX in die grondwater onder die skoongemaakte area was 4.34mg/l en by die Acacia area was dit 3.78mg/l; hierdie waardes is onder die drempel vir nitraatbesoedeling in grondwater. Die nitraat inhoud van die grondwater het wel beduidend toegeneem as gevolg van verwydering van A. saligna. Die gevolgtrekking was dat daar ‘n verandering plaasvind in die voeding status van grond met Acacia saligna indringing en weer met verwydering. NOX migrasie na die grondwater verhoog met verwydering van plantegroei. In hierdie studie was die nitraat besoedeling drempel van 10mg/l nitraat N nie bereik nie.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. / The fynbos eco-region in the Western Cape lowlands has been extensively transformed by anthropogenic activities such as agriculture and urban development, as well as invasive alien plants. Elandsberg Private Nature Reserve and Farms lies on Swartland Alluvium Fynbos and has been largely fragmented by agricultural crop production, whilst Riverlands Nature Reserve together with the Pella Research Site, which lie on Atlantis Sand Fynbos, are under severe threat from the invasive woody alien Port Jackson Willow (Acacia saligna) which forms dense stands in the lands adjacent the nature reserve. Habitat transformation has resulted in subsequent loss of habitat and a reduction in habitat value for small mammal communities by creating a mosaic of optimal and sub-optimal habitats. The success of A. saligna is, in part, attributed to its production of copious amounts of small hard-shelled seeds and well established soil seed banks. In the first part of this study we investigated the effect of habitat transformation on resident small mammal communities by comparing small mammal species richness, diversity and abundance between natural and transformed habitats as well as between the two vegetation types. We also investigated the population demographics of the striped mouse (Rhabdomys pumilio) in the different habitats. Our study shows that whilst fragments of natural habitats, especially at Riverlands and Pella, may be playing an important role in harbouring rare and possibly endangered species, transformed habitats are also important as secondary habitats providing both cover as well as seasonal food resources. Reproduction and body condition in R. pumilio were dependent on seasonal changes such as availability of water and food resources in the habitats. The second part of this study was carried out to investigate the effect of alien plant invasion on the resident small mammal communities at Riverlands Nature Reserve and to determine the role of small mammals in the removal and predation of A. saligna seeds. Rodent species richness, diversity and abundance were very low in the A. saligna stands compared to the adjacent fynbos vegetation. The interaction of rodents with seeds (removal or predation) was dependent upon seed size and seed abundance in the habitats. Whilst rodents may play an important role in predator limitation in the acacias, it is also possible that they may be playing a significant role in dispersing the seeds of acacias into the fynbos. More work is required to fully understand the role small mammals play in seed predation, dispersal and limitation in alien invaded fynbos systems.

Submitted by JOÃO CARLOS BIAZZON null (carlosbiazzon@bol.com.br) on 2016-12-19T16:22:00Z No. of bitstreams: 1 Dissertação João Carlos Biazzon.pdf: 9362825 bytes, checksum: 73ab148e606959b23c89521eeb67a86e (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-21T10:59:59Z (GMT) No. of bitstreams: 1 bizzon_jc_me_bauru.pdf: 9362825 bytes, checksum: 73ab148e606959b23c89521eeb67a86e (MD5) / Made available in DSpace on 2016-12-21T10:59:59Z (GMT). No. of bitstreams: 1 bizzon_jc_me_bauru.pdf: 9362825 bytes, checksum: 73ab148e606959b23c89521eeb67a86e (MD5) Previous issue date: 2016-12-07 / O presente trabalho teve como objetivo, verificar o desempenho de juntas coladas em função da qualidade das superfícies da madeira usinadas em operações de fresamento cilíndrico tangencial para diferentes velocidades de avanço, empregando-se quatro tipos de adesivos à base de Poliacetato de Vinila (PVAc) denominados como C1, C2, C3 e C4 e madeira da espécie Eucalyptus saligna. Para tanto, foram confeccionadas amostras para ensaios normatizados pela Norma ABNT - NBR 7190:1997, submetidas a testes de resistência à ruptura na linha de cola por esforços de cisalhamento. Na união das peças de madeira para confecção das amostras, essas foram coladas em planos aleatórios em relação aos anéis de crescimento da madeira. As amostras foram usinadas empregando-se as velocidades de avanço V1= 6,0; V2 = 11,0; V3 = 16,0 e V4 = 21,0 m.min-1, correspondendo, respectivamente aos avanços por dente “fz”: 0,25 mm; 0,45 mm; 0,66 mm e 0,87 mm. Pôde-se verificar um melhor desempenho para uso do adesivo “C4” e melhor superfície de adesão para a velocidade de avanço V1 = 6,0 m.min-1. Dos resultados podem-se destacar o melhor desempenho empregando-se o adesivo C4, e o pior desempenho o adesivo C2 para todas as velocidades de avanço testadas. / The present work aimed at verifying the performance of bonded joints in function to the quality to the wood surfaces machined tangential cylindrical milling operations to different advance speeds, using four types of adhesives based on vinyl polyacetate (PVAc) denominated as C1, C2, C3 and C4 and wood species Eucalyptus saligna. For this, samples were prepared for standardized tests by ABNT - NBR 7190:1997, subjected to tensile strength tests on the glue line shear efforts. In the union of pieces of wood for making the samples, these were glued on random plans in relation to the wood growth rings. The samples machined using the advance speed V1 = 6.0; V2 = 11.0; V3 = 16.0 and V4 = 21.0 m. min-1, corresponding respectively to advances by tooth "fz": 0.25 mm; 0.45 mm; 0.66 mm and 0.87 mm. It was verified better performance for adhesive use "C4" and better adhesion surface for the advance speed V1 6.0 m. min-1. From the results, it can be highlighted the best performance using the C4 adhesive, and the worst performance C2 adhesive for all tested advance speeds.

The aim of this diploma thesis is tree planting method comparison of water retention improving technology (Improve pits) and non-improving technology (Pits). Research was realized on the „Sustainable management of soil, forest and water resources as the pilot model for the rural development in SNNPRS, Ethiopia“ project areas. This project was realized by Mendel university in Brno. Terrain investigations, experimental plot set up and soil sample collection and analyses were realized by devised methodology. Terrain works took a place during July and August 2016. When comparing resulting values, it became clear that the Improve pits technology shows positive effect on soil water retention capacity and its gradual release. This effect creates more suitable conditions for regeneration of damaged vegetation.

Mixed-species plantations of eucalypts and acacias have the potential to improve stand productivity over that of respective monocultures through the facilitative effect of nitrogen-fixation by acacias, and increased resource capture through above- and belowground stratification. However, growth in mixed-species plantations may not be improved compared to that of monocultures when competitive interactions outweigh the effects of improved nutrient availability and resource capture. Careful selection of sites and species is therefore critical to successfully improving stand productivity using mixed-species plantations. This study set out to examine some of the processes and interactions that occur in mixed-species plantations, and the effect nutrient and water availability can have on the growth of mixtures. In three out of four mixed-species field trials examined in this study, growth was not increased in mixtures compared to monocultures. However, in the fourth field trial, heights, diameters, stand volume and aboveground biomass were higher in mixtures of E. globulus and A. mearnsii from 3-4 years after planting. The range in outcomes from mixing species in these four trials shows that a fundamental understanding of the underlying processes is required to enable a greater predictive capacity for the circumstances under which mixtures will be successful. Therefore the growth dynamics, processes and interactions were examined in the mixtures of E. globulus and A. mearnsii. The difference in productivity between mixtures and monocultures in this trial increased with time up to age 11 years, when 1:1 mixtures contained twice the aboveground biomass of E. globulus monocultures. The positive growth response of trees in mixture compared to monocultures was the result of accelerated rates of nutrient cycling, a shift in C allocation and reductions in light competition through canopy stratification. Nitrogen contents of foliage and soil clearly showed that A. mearnsii influenced the N dynamics in this trial. If these changes in N contents were due to N fixation by A. mearnsii, then about 51 and 86 kg N ha-1 yr-1 was fixed in the 1:1 mixtures and A. mearnsii monocultures, respectively. Nitrogen fixation was also examined using the natural abundance method. The delta15N values of foliage collected at 10 years were grouped according to the mycorrhizal status of the host plant. Therefore the discrimination of 15N during transfer from mycorrhizae to the host plant appeared to vary with mycorrhizal status, and the natural abundance of 15N was not used to quantify N fixation. Rates of N and P cycling in litterfall were significantly higher in stands containing at least 25% A. mearnsii (more than 31 kg N ha-1 yr-1 and more than 0.68 kg P ha-1 yr-1) compared to E. globulus monocultures (24 kg N ha-1 yr-1 and 0.45 kg P ha-1 yr-1). Rates of litter decomposition and N and P release were about twice as high in 1:1 mixtures compared to E. globulus monocultures and were even higher in A. mearnsii monocultures. It is therefore important to select N-fixing species that are capable of cycling nutrients quickly between the plant and soil, and that have readily decomposable litter. The total belowground C allocation was not significantly different between mixtures and monocultures (14 to 16 Mg C ha-1 yr-1). However, since aboveground net primary production was greater in 1:1 mixtures, the changes in nutrient availability appears to have increased total productivity (both above- and belowground), and reduced the proportion of C allocated belowground in mixtures compared to E. globulus monocultures. In a pot trial containing mixtures of E. globulus and A. mearnsii both species grew larger in mixture than in monoculture at low N levels, and mixtures were more productive than monocultures. However, at high N levels, E. globulus suppressed A. mearnsii and mixtures were less productive than E. globulus monocultures. Similar effects were found for high and low levels of P. Therefore resource availability can have a strong influence on the interactions and growth of mixtures. The productivity of mixtures may only be increased on sites where the resource for which competition is reduced in mixture is a major limiting growth resource. For example, if N is not a limiting growth factor then an increase in N availability from N-fixation may not increase growth, and the N-fixing species may compete for other resources such as soil P, moisture or light. This study has shown that mixtures containing a N-fixing trees and a non-N-fixing trees can be more productive than monocultures, but that this increase in productivity will only occur on certain sites. Examination of the growth, interactions and processes that occurred in mixtures in this study provide useful information that can aid the selection of species combinations and sites.

The aim of this study was to isolate and characterize antifungal compounds from the most active medicinal plant species that could be used to address secondary infection problems in immunocompromised patients. An ethnobotanical study was conducted and 45 medicinal plant species used traditionally to treat candidiasis and related infections in HIV/AIDS patients were identified and documented. The most popular plant species used included Acacia caffra, Clerodendrum glabrum, Croton gratissimus, Elaeodendron transvaalense, Faurea saligna, Hippocratea longipetiolata, Osyris lanceolata, Richardia brasiliensis, Schkuhria pinnata, Schotia brachypetala, Spilanthes acmella, Strychnos potatorum, Vangueria infausta subsp. infausta and Withania somnifera. The plant parts used in the therapeutic preparations were roots (26.7%), bark (22.2%), and a combination of roots and bark (17.7%). Decoctions (44.4%), infusions (20%) and macerations (17.7%) were used. Most of the herbal remedies were administered orally. Chemical profiles of the plant species were established by using thin layer chromatography. Leaf extracts of these plant species were tested for antimicrobial activity against two common pathogenic fungal species in humans (Candida albicans and Cryptococcus neoformans) and four nosocomial bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa) using a two-fold serial microdilution method and bioautography. All plant species investigated had some degree of antimicrobial activity against the test microorganisms. The hexane and the acetone extracts of Clerodendrum glabrum, Hippocratea longipetiolata, Schkuhria pinnata and Withania somnifera were the most active with MIC values ranging from 0.06 to 0.08 mg/ml. The most susceptible pathogen to the test samples was C. neoformans while C. albicans was resistant to most of the plant extracts. The water extracts of Withania somnifera and Hippocratea longipetiolata (14%) had MIC < 1 mg/ml against C. albicans. C. neoformans was susceptible to nine water plant extracts (64%) with MIC < 1 mg/ml and the promising activity was observed in Hippocratea longipetiolata and Faurea saligna extracts with MIC values of 0.16 and 0.31 mg/ml respectively. The hexane extract of C. glabrum was the most active against C. albicans with an MIC value of 0.06 mg/ml and total activity of 550 ml/g. In the bioautography, most plant extracts tested had few active compounds, others had no active components at all and this may be attributed to the disruption of synergism by the thin layer chromatography. C. glabrum had eight active antifungal compounds on bioautograms and most of these components were observed in the EMW solvent system. Based on this and its wide distribution in rural areas, C. glabrum was chosen for further study. The antioxidant activity and possible immune boosting potential of the species were determined using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), 2, 2’ azinobis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. In the DPPH qualitative assay, the aqueous plant extracts had several prominent antioxidant components than the organic plant extracts. The aqueous plant extracts which had the most prominent antioxidant activity were F. saligna with 8 compounds, followed by E. transvaalense, H. longipetiolata O. lanceolata, R. brasiliensis and S.brachypetala, with five compounds each and their Rf values ranged from 0;06 to 0.94. This appears to validate the ethnomedicinal use of the plant species to some extent because decoction is the most common method used in the preparation of the remedy by the traditional healers. With regard to the organic plant extracts, only one plant extract, F. saligna had two prominent antioxidant components at Rf values 0.81 and 0.88. A third of the plant species had a high level of free radical scavenging activities in the DPPH, ABTS and FRAP assays. However, all plant extracts had lower antioxidant activity than the positive control (Trolox) used. The selected plant species were also evaluated for their in vitro toxicity against the Vero monkey kidney cell line using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay. The acetone plant extracts of O. lanceolata, S. acmella, S. pinnata and S. brachypetala had high cytotoxic activity against Vero cells with IC50 values of 13.7±0, 19.9±0.001, 21.6±0.001 and 28.34±0.001 μg/ml respectively. However, their IC50 values were higher than that of the positive control, doxorubicin (IC50 = 9.9±0 μg/ml). The rest of the acetone plant extracts (64%) had moderate cytotoxic activity (30 < IC50<100 μg/ml). The aqueous plant extracts were relatively non-toxic to the Vero cells with IC50 values ranging from 137 to > 500 µg/ml. This supports the use of aqueous extracts in the traditional medicine. However, their low selectivity index values ranging from 0.26 to 1.68 suggest that the plant extracts are probably suitable for external use only. Fractionation of the hexane extract of the leaves of C. glabrum by chromatographic techniques yielded six fractions of which fractions C and D had significant antifungal activity (average MIC value = 0.1 mg/ml) against C. albicans and C. neoformans. From these fractions, one new triterpenoid, 3-(1-oxobutyl)-11α-hydroxytaraxast-20(30)-ene-24,28-dioic acid (clerodendrumic acid) (1) was isolated along with known heptadecanoic acid (2). C. albicans was relatively insensitive to clerodendrumic acid (1) (MIC value = 125 µg/mL) and was resistant to heptadecanoic acid (2) (MIC value = 188 µg/ml). Compounds 1 and 2 were non-toxic against monkey kidney Vero cells in vitro with IC50 values of 202.6 and 108.4 µg/ml respectively. Due to its low antifungal activity, the novel compound clerodendrumic acid (1) is not a viable candidate for drug development which could be used to combat candidiasis and related fungal infections. However, due to its relative safety, it may possibly be used as a lead compound to produce new chemically modified active derivatives or could be used together with known antibiotics to mitigate their undesirable side effects. To the best of our knowledge, the isolation of a novel, clerodendrumic acid (1) and a known heptadecanoic acid (2) compounds from leaf extracts of C. glabrum is reported herein for the first time. The results obtained from this study generally substantiate the rationale behind the use of the selected plant species in the traditional medicine to treat candidiasis and related infections to some extent. This study showed the potential of studying traditional medicine in the search for effective plant extracts or new lead compounds that could be developed into drugs for combating microbial infections among the rural poor people. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Paraclinical Sciences / Unrestricted