Thesis (MSc (Conservation Ecology and Entomology)--University of Stellenbosch, 2006. / Swartland Shale Renosterveld is restricted to fertile fine-grained soils in the winter rainfall region of the Western Cape. Between 91% and 97% of this vegetation type is transformed, mostly due to agriculture. Remaining fragments have an irreplaceable conservation value due to a high richness of endemic geophytes. Information on renosterveld vegetation composition and response to disturbance is sparse. Research occurred at three sites near Wellington: Voëlvlei Provincial Nature Reserve (CapeNature), Elandsberg Private Nature Reserve (Elandsberg Farms (Pty.) Ltd.), and Krantzkop munitions factory (Armscor/Somchem) forming a contiguous fragment in the Agter- Groeneberg Conservancy. The primary research aim was to identify or ascertain patterns of plant succession in Swartland Shale Renosterveld and associated different-aged old fields (previously ploughed), with the interaction of grazing. The key research questions are: (1) What are the plant communities of unploughed renosterveld and different-aged old fields which originated in habitats of ploughed renosterveld? (2) What are the most characteristic features of the floristic and ecological relationship between the described plant communities in terms of ecological factors operating within the studied system? (3) Does total species and life-form group richness differ between natural vegetation and old fields? (4) Is life-form richness influenced by ploughing and grazing or the interaction between these disturbances? (5) Is life-form cover-abundance influenced by ploughing and grazing or the interaction between these disturbances? (6) Does alien plant species richness differ amongst seres, and with different levels of grazing intensity? A comparison of life-form richness and cover-abundance of old field vegetation was made with adjacent natural unploughed “controls”. The effects of ploughing on community structure, with the inclusion of grazing was established. These life-form richness comparisons also occur across a gradient of increasing large mammalian herbivore grazing intensity. Sampling was conducted in winter and spring using nested 1000m2 relevés. A hierarchical classification, description and floristic interpretation of renosterveld and old field vegetation were made using TWINSPAN, SYN-TAX 2000 and CANOCO. The samples were classified with TWINSPAN and two communities were described at the association level, namely: Ursinia anthemoides–Cynodon dactylon Grassland Community (with two variants) and the Pterygodio catholici–Elytropappetum rhinocerotis Shrubland Community (with two subassociations), respectively. The vegetation data were further hierachically classified using SYNTAX 2000 which revealed similar clustering of sample objects to that resulting from classification and ordination. Following ordination of sample objects with CANOCO, select groups of species were used to depict their response curves in relation to seral development. Briefly it was found that the effects of grazing vs. non-grazing was more pronounced on old fields than in unploughed vegetation. Overall total species and life-form richness was reduced by ploughing with old fields requiring a recovery period of 30 years to resemble unploughed vegetation. Keywords: Swartland Shale Renosterveld, phytosociology, vegetation patterns, life-forms, succession, disturbance, ploughing, grazing, old fields.

Thesis (MScConsEcol (Conservation Ecology and Entomology)--University of Stellenbosch, 2006. / The Constitution of the Republic of South Africa promotes participatory, cooperative governance and environmental conservation. This constitutional directive is enhanced into the National Environmental Management Act and other conservation laws. These legal requirements for active community participation in natural resources management, including benefit sharing are sufficiently captured in the SANParks’ policy and strategy for the management of national parks.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosc, 2007. / Freshwater insect species and their host ecosystems are widely threatened, particularly within agricultural and urban landscapes of Mediterranean areas, including that of the Western Cape Province, South Africa. The study here determined the biodiversity value of nineteen artificial ponds (temporary and permanent) and two river margin sites in the Cape Floristic Region (CFR). The aim was to determine aquatic beetle and bug abundance and species richness in these ponds, a topic which has been hardly explored in South Africa. Sites were sampled from September 2005 to September 2006. A total of 18 677 aquatic beetle and bug individuals were sampled, representing 43 genera (28 beetle and 15 bug genera), 64 species (44 aquatic beetle and 20 bug species). Different pond types had distinct species assemblages. The associated physico-chemical characteristics of these sites were also investigated. The key environmental variable affecting aquatic beetle and bug distribution was naturalness (no human and environmental impact on waterbody). The results showed that the most important determinant of aquatic beetle and bug species richness across all sites was emergent macrophytes, such as Typha capensis and Persicaria decipiens. Artificial ponds in the CFR clearly increase the area of occupancy for insects, and therefore play a major role in conserving them. This is especially so when the ponds are at moderate temperatures (i.e. 19º C). Although all ponds contributed to the aquatic beetle and bug diversity in the region, they differed in relative value, depending on the combination of environmental variables affecting each pond.

Thesis (MScConEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Previously, conservation activities were mainly focussed upon the establishment of protected areas that safeguarded and shielded the natural world from misuse, often resulting in the forced removal of indigenous communities. In South Africa, the ≠Khomani Bushmen, were one such group forcibly evicted from their homelands. Today, the community has regained access to their ancestral lands in the form of a land claim, settled in 1999, that awarded the community land rights in the form of six farms and land use rights within the now Kgalagadi Transfrontier Park (KTP). This gave them the right to use and manage their property falling within the park together with the conservation authority responsible for the Park, South African National Parks (SANParks). This study aims to improve our understanding of the use of resources by the ≠Khomani Bushmen. By obtaining insight on resource use and how knowledge of this use is transferred and shared, information on how to better involve and integrate the community in management processes is generated. The study identified the most important plants currently used within the ≠Khomani community and assessed this use. Additionally, social network analysis (SNA) was used to investigate how the social network structure depicts the distribution of knowledge which affects the community’s ability to manage their natural plant resources effectively. In an ethnobotanical survey, over 90 individuals were interviewed, using semi-structured interviews, on the farms awarded to the community. In total, 59 plant species from 28 families were found to be in use. Medicinal plants were most frequently cited (60%), with edible plants comprising a further 20%. Data was also collected on social relations surrounding the acquisition, generation and transfer of plant use knowledge. The knowledge networks all depict isolated individuals on the periphery and a few individuals loosely connected to central structures. This study demonstrates that wild plant use remains an important practice for the ≠Khomani people, primarily for medicinal purposes. It serves as baseline data on plant resources being used by the community and adds to our understanding of how traditional knowledge is being transmitted. The insight provided by SNA depicts the current distribution of knowledge and should be used by the community, as supported by network weavers and SANParks, to achieve their joint management goals. Network weaving can potentially counteract ecologically unsustainable practices, promoting collaboration and the transfer of traditional ecological knowledge. / AFRIKAANSE OPSOMMING: Voorheen was bewaringsaktiwiteite meestal gefokus op die vestiging van beskermde areas wat die natuurlike wêreld beveilig en beskerm het van misbruik wat dikwels die gevolg was van die geforseerde verwydering van inheemse gemeenskappe. In Suid-Afrika was die ≠Khomani Boesman groep een van die sodanige groepe wat op ʼn indrukwekkende manier van hulle tuislande uitgesit is. Vandag het die gemeenskap weer toegang gekry tot die land van hulle voorvaders in die indiening van ʼn grond eis wat in 1999 vasgestel is, en wat die gemeenskap grond regte toegeken het in die vorm van ses plase en grond regtelike gebruik binne die sogenoemde Kgalagadi Transfrontier Park (KTP). Dit het hulle die reg gegee tot die gebruik en bestuur van hulle eiendom wat binne die park val saam met die bewaringsowerhede wat verantwoordelik is vir die Park, Suid-Afrikaanse Nasionale Parke (SANParks). Die doel van hierdie studie is om ons begrip te verbeter van die gebruik van hulpbronne deur die ≠Khomani Boesman. Met die verkryging van insig oor hulpbron gebruik en hoe die kennis van hierdie gebruik oorgedra en gedeel word, is inligting oor hoe om ʼn beter betrekking en integrering van die gemeenskap in die bestuursprosesse gegenereer. Die studie het die belangrikste plante geïdentifiseer wat tans gebruik word binne die ≠Khomani gemeenskap met die doel om die gebruik van hierdie plante te assesseer. Sosiale netwerkanalise (SNA) is addisioneel gebruik om ondersoek in te stel oor hoe sosiale netwerk struktuur die verspreiding van kennis uitbeeld wat die gemeenskap se vermoë om hulle natuurlike plant hulpbronne effektief te bestuur affekteer. In ʼn etnobotaniese opname, was oor 90 individuele ondervra op die plase wat aan die gemeenskap toegeken was, met die gebruik van semi-gestruktureerde onderhoude. Dit is gevind dat in totaal 59 plant spesies uit 28 families gebruik word. Medisinale plante was meer dikwels aangehaal (60%) met eetbare plante bestaande uit 20%. Data was ook versamel oor sosiale verwantskappe omringende die verkryging, generering en oordra van kennis in die gebruik van plante. Hierdie netwerk van kennis word alles uitgebeeld in geïsoleerde individue op die periferie en ʼn paar individue wat losweg verbonde is tot sentrale strukture. Hierdie studie identifiseer dat die gebruik van wildeplante ʼn belangrike praktyk bly vir die ≠Khomani mense, hoofsaaklik vir medisinale doeleindes. Dit dien as basis inligting van plant hulpbronne wat tans gebruik word deur die gemeenskap en wat by ons begrip gevoeg word oor hoe tradisionele kennis oorgedra word. Die insig wat deur SNA voorsien word beeld die huidige verspreiding van kennis uit, wat deur die gemeenskap gebruik moet word, as ondersteuning van “network weavers” en SANParks om hulle gesamentlike bestuur doelwitte te bereik. “Network weavers” kan potensieel ekologiese onvolhoubare praktyke teenwerk, wat die samewerking en die oordra van tradisionele ekologiese kennis bevorder.

Thesis (MScConEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: I evaluated the impact of Prosopis invasion and clearing on ecological structure, function and agricultural productivity in heavily grazed Nama Karoo rangeland on two sheep farms near the town of Beaufort West in the Western Cape Province of South Africa. My aims were to (1) determine the effects of invasion and clearing on rangeland vegetation composition, diversity (alien and indigenous species richness) and structure (alien and indigenous species cover), soil vegetation cover (plant canopy and basal cover) and agricultural productivity (grazing capacity), (2) describe the vegetation processes that underlay the invasion and clearing impacts and (3) evaluate the success of clearing in facilitating unaided restoration of ecological structure, function and agricultural productivity in formerly invaded rangeland. I hypothesised that invasion would significantly change rangeland vegetation composition and structure, leading to greater alien species richness and cover and lower indigenous species richness and cover while clearing would lead to lower alien species diversity and cover and greater indigenous species richness and cover. In addition I hypothesized that invasion would reduce rangeland plant canopy and basal cover and grazing capacity while clearing would substantially increase them. Finally I predicted that vegetation composition, alien and indigenous species cover and richness, plant canopy and basal cover and grazing capacity would revert to pre-invasion status and levels within four to six years of clearing. My results suggest that in heavily grazed Nama Karoo rangeland Prosopis invasion (~15 percent canopy cover) and clearing can significantly change rangeland vegetation composition, with invasion leading to greater alien species cover and lower indigenous species richness, while clearing leads to lower alien species richness and cover and greater indigenous species richness and cover. However invasion seems to have no effect on alien species richness and overall indigenous species cover. Clearing appears to facilitate the spontaneous restoration of alien species cover and indigenous species richness within four to six years but not species composition, alien species richness and indigenous species cover. In addition my results also indicate that Prosopis invasion can lower rangeland plant canopy and basal cover and grazing capacity while clearing, even under heavy grazing, can substantially raise them. Clearing however does not seem to facilitate the restoration of rangeland plant canopy and basal cover and grazing capacity to pre-invasion levels within four to six years after clearing. / AFRIKAANSE OPSOMMING: Ek het die impak van Prosopis indringing en verwydering van indringers op ekologiese struktuur, funksie en landbou produktiwiteit in ‘n swaar beweide Nama Karoo gebied op twee skaapplase naby Beaufort-Wes in die Wes-Kaap provinsie van Suid-Afrika geëvalueer. My doelwitte was om (1) te bepaal wat die gevolge van die indringing en verwydering van indringers op die natuurlike plantegroei samestelling, diversiteit (uitheemse en inheemse spesiesrykheid) en struktuur (uitheemse en inheemse spesies bedekking) sal wees, sowel as die effek op plantegroei bedekking (kroon en basalebedekking) en landbou produktiwiteit (weidingkapasiteit), (2) die plantegroei prosesse te beskryf wat onderliggend deur die impakte van indringing en verwydering van indringers veroorsaak word, en (3) die sukses van die verwydering van indringers te evalueer deur die fasilitering van blote restorasie van ekologiese struktuur en funksie en landbou produktiwiteit in voorheen ingedringde gebiede. My hipotese is dat indringing ‘n aansienlike verandering in natuurlike plantegroeisamestelling en struktuur sal veroorsaak, wat sal lei tot groter uitheemse spesiesrykheid en bedekking met minder inheemse spesiesrykheid en bedekking, terwyl die verwydering van indringers sou lei tot minder uitheemse spesie diversiteit en bedekking met 'n groter inheemse spesiesrykheid en bedekking. Verder vermoed ek dat indringing die natuurlike kroon- en basalebedekking en weidingkapasiteit sal verminder, terwyl die verwydering van indringers dit aansienlik sal verhoog. Ten slotte voorspel ek dat plantegroei samestelling, uitheemse en inheemse spesiesbedekking en -rykheid, kroon- en basalebedekking en weidingkapasiteit sou terugkeer na voor-indringing status en vlakke binne vier tot ses jaar na die verwydering van indringers. My resultate daarop dat die indringing van Prosopis (~ 15 persent kroonbedekking) en die verwydering van indringers in swaar beweide Nama Karoo gebiede ‘n aansienlike verandering in die gebied se natuurlike plantegroei samestelling toon, waar indringing gelei het tot groter uitheemse spesiesbedekking en minder inheemse spesiesrykheid, terwyl die verwydering van indringers lei tot minder uitheemse spesiesrykheid en groter inheemse spesiesrykheid en - bedekking. Dit lyk egter of indringing geen effek op uitheemse spesiesrykheid en algehele inheemse spesiesbedekking het nie. Die verwydering van indringers blyk om die spontane herstel van indringerbedekking en inheemse spesiesrykheid binne vier tot ses jaar te fasiliteer, maar nie spesiesamestelling, uitheemse spesiesrykheid of inheemse spesiesbedekking nie. Benewens dui my resultate ook aan dat Prosopis indringing die natuurlike kroon- en basalebedekking sowel as weidingskapasiteit verlaag, terwyl die verwydering van indringers, selfs onder swaar beweiding, die bedekking aansienlik kan verhoog. Verwydering van indringers lyk egter nie asof dit die herstel van die gebied se natuurlike kroon- en basalebedekking en weidingkapasiteit na voor-indringing vlakke toe kan fasiliteer binne vier tot ses jaar na die verwydering van indringers nie.

Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Soil is a fundamental, non-renewable resource in any ecosystem. To uphold food production for increasing global human populations, it is imperative to develop ways in which to sustain healthy biological productivity and sustainability of agricultural soils. Nematodes are one of the most abundant groups of Metazoa occurring in all soils, and form an integral part of the soil food web at several trophic levels. They respond rapidly to changes within their environments, and can easily be extracted from soil, identified and characterised into functional guilds. Nematodes thus have the potential to impart insight into the condition of the soil food web. This study aims to establish whether nematodes will be suitable bio-indicators of soil health for the deciduous fruit industry in the Western Cape. Three different objectives have been set to determine the practical use of nematode community structures as a tool for the measurement of soil health. The objectives include describing the nematode community structure, biodiversity and functionality within Fynbos soils; the characterization of organic and conventional orchards; and the differences in nematode soil communities in differently managed soils in an apple orchard. The number of nematodes in each soil sample was quantified and identified to family level. The nematode biodiversity and functionality for each site was determined by evaluating the nematode food webs for trophic group distribution, as enumerated by the Maturity Index (MI), the Enrichment Index (EI), the Structure Index (SI), the Basal Index (BI) and the Channel Index (CI), based on the weighted abundance of coloniser-persister guilds. The functional guild analysis of Fynbos samples indicated that the enrichment and the structure of any given sample were not bound to a certain area, but it was representative of each of the four quadrats within the faunal analysis. Different geographic areas were found to differ in nematode diversity and functionality, which was mainly associated with dominant plant families and species (such as strong associations between Fynbos families Fabaceae, Solanaceae and Celestraceae with the nematode family Pratylenchidae). The most abundant nematode families present in the Fynbos were Tylenchidae, which are plant-feeding nematodes, and Cephalobidae which are bacterial-feeding nematodes. Despite Tylenchidae and Cephalobidae both having coloniser-persister values (cp-values) of two, they are split up into different feeding types. Cp-2 nematodes are tolerant to disturbances, and occur in all environments. Only one omnivorous family, the Dorylaimida, was identified in Fynbos samples. The average MI value for Fynbos was found to be very low, with a mean value of 1.26. The value obtained indicated the presence of taxa with tolerance to disturbance, which, in turn, indicated the presence of a disturbed soil, in general. The number of plant-parasitic nematodes within the Fynbos soils was low, which was supported by the low plant-parasitic index (PPI) of 0.85. The diversity, richness and evenness values were low, indicating low nematode diversity, but a distribution of abundances amongst the families. The average Hill’s N0 index value was 8.0, indicating that, in general, eight nematode families would have been present in a Fynbos soil sample. A study was done to determine the biodiversity and the functionality of the nematodes associated with deciduous fruit orchards that were conventionally, or organically, managed. Herbivores were dominant in all the orchards. The organic apple orchard had the lowest numbers of herbivores and fungivores, with the highest number of carnivores. When comparing organic and conventional apricot orchards, higher numbers of plant-parasitic nematodes were found in the organic orchard. Criconematidae occurred in higher numbers in conventional apricot orchard soil. When comparing organic apricots and apples, higher numbers of Criconematidae occurred within the organic apple soil. Overall, higher levels of plant-parasitic nematodes occurred in the organic apricot orchard. The MI indicated that all orchard soils had values below 1.5, indicating disturbance. Conventionally managed apricot orchard soil had the highest MI value of 1.48. The PPI value was highest in organically managed apricot orchards. All orchard soils were located within Quadrat B of the faunal analysis, indicating enrichment and structure. Regarding the diversity, richness and evenness of the distribution, conventional apricot soil had the highest species richness, while organic apple soil had the most even family distribution. Different management practices did not show marked differences in community composition and structure. The species richness of Fynbos soils was comparable to those of deciduous fruit orchards. Soil samples from eight different soil surface treatments were collected from an apple orchard in the Grabouw area. Treatments were combined according to the soil surface treatments received (chemical control of cover crops and weeds, mulch and mulch + effective micro-organism spray). Bacterivores were dominant in all soil treatments, with the least number being present in the chemical control (of cover crops and weeds) treatment. Sites which received chemical control of cover crops and weeds had higher levels of fungivores, compared to the levels at the other sites. High numbers of Rhabditidae occurred within mulch and mulch + effective micro-organism (EM) treatment sites, while high numbers of Aphelenchidae occurred in chemical control sites. The carnivorous family Ironidae only occurred in mulch + EM sites. Strong associations were found between soil surface applications and nematode families present within the soil. Chemical control (of cover crops and weeds) applications had the highest MI value, while values were equal for the other soil applications. The faunal analysis indicated that the mulch and the chemical control fell within Quadrat A, indicating enriched, but unstructured, soil, while the mulch + EM treatment fell within Quadrat B, indicating enrichment and structure, as well as good overall soil conditions. All the systems were dominated by bacterial decomposition pathways. Controversially, sites that received chemical control of the cover crops and weeds had the highest species richness of all three applications, as well as the highest level of diversity, according to the Simpson Index. As only the cover crops and the weeds were chemically controlled, the soil can be regarded as undisturbed, which explains the results obtained in this study. Clear differences in nematode community structure and composition were observed between the different soil applications in the apple orchard. / AFRIKAANSE OPSOMMING: Grond is 'n fundamentele, nie-hernubare hulpbron binne enige ekosisteem. Ten einde voedselproduksie vir die toenemende globale menslike bevolking te handhaaf, is dit noodsaaklik om maniere te ontwikkel om gesonde biologiese produktiwiteit en volhoubaarheid van landbougrond in stand te hou. Nematodes is een van die volopste Metazoa in alle gronde en vorm 'n integrale deel van die grond voedsel-web op verskeie trofiese vlakke. Hulle reageer vinnig op veranderinge binne hul omgewings, kan maklik ekstraheer en identifiseer word; en ook maklik in funksionele gildes ingedeel word. Nematodes het ook die potensiaal om insig oor te dra ten opsigte van die toestand van die grond voedsel-web. Hierdie studie het ten doel om vas te stel of nematodes geskikte bio-indikatore van grond gesondheid kan wees spesifiek vir die sagtevrugte bedryf in die Wes-Kaap. Drie verskillende doelwitte is gestel om die praktiese gebruik van nematode populasie samestelling as 'n instrument vir die meting van grond gesondheid te gebruik. Die doelwitte sluit in die nematode populasie samestelling, biodiversiteit en funksionaliteit binne natuurlike Fynbos; organies verboude versus konvensionele boorde; en die verskil in nematode populasie samestelling tussen verskillend behandelde en bestuurde grondpersele binne ʼn appel boord. Die nematode biodiversiteit en funksionaliteit vir elke perseel was bepaal deur die evaluering van die nematode voedselweb vir trofiese groep verspreiding en enumerering deur die Maturity Index (MI) en die Enrichment Index (EI), Strukturele Indeks (SI), Basale Indeks (BI) en Channel Index (CI) wat gebaseer is op die geweegde oorvloed van koloniseerder-persister gildes. Die funksionele gilde vir Fynbos monsters het aangedui dat die verryking en struktuur van enige gegewe perseel nie gebonde is aan ʼn bepaalde gebied nie, aangesien dit verteenwoordig was in elk van die vier kwadrante van die Fauna Analiseerder. Daar is gevind dat verskillende areas verskil in nematode diversiteit en funksionaliteit, wat hoofsaaklik geassosieer was met die dominante plant families en spesies in die omgewing. Die volopste nematode familie wat teenwoordig was in die Fynbos was Tylenchidae, wat plant-voedende nematodes is, en Cephalobidae, wat bakterie-voedend is. Tylenchidae en Cephalobidae het beide ʼn cp-waarde van twee, maar is verdeel in verskillende VIII tipes voedingsgroepe. Die cp-2 nematodes is verdraagsaam vir versteurings en kom in alle omgewings voor. Slegs een omnivoor familie is geïdentifiseer in Fynbos monsters, nl. die Dorylaimidae. Die gemiddelde MI waarde vir Fynbos was laag, met 'n gemiddelde waarde van 1.26. Hierdie waarde is ʼn aanduiding van die teenwoordigheid van taxa met verdraagsaamheid tot versteuring, wat op sy beurt 'n versteurde grond in die algemeen aangedui het. Die aantal plant-parasitiese nematodes binne die Fynbos-gronde was laag, wat ondersteun word deur die lae PPI-waarde van 0.85. Die waardes vir die diversiteit, spesie-rykheid en egaligheid was laag, wat dui op 'n lae nematode diversiteit, maar 'n egalige verspreidings onder families. Die Hill’s N0 indeks waarde was gelyk aan 'n gemiddelde van 8.0 en dui daarop dat in die algemeen agt nematode families teenwoordig sal wees in 'n Fynbos grondmonster. 'n Studie is gedoen om die biodiversiteit en funksionaliteit van nematodes wat verband hou met vrugteboorde wat organies en konvensioneel bestuur is te bepaal. Herbivore was dominant in alle boorde. Organiese appels het die laagste aantal herbivore en fungivore gehad en die hoogste aantal karnivore. Wanneer organiese en konvensionele appelkoosboorde met mekaar vergelyk is, was hoër getalle van plant-parasitiese nematodes gevind in die organiese boord. Criconematidae was teen ʼn groter aantal in die grond van die konvensionele appelkoosboord gevind. Met die vergelyking van organiese appelkose en appels word, is ʼn hoër aantal Criconematidae binne die organiese appelgrond aangetref. In die algemeen was hoër vlakke van plant-parasitiese nematodes gevind in die organiese appelkoosboord. Die MI het getoon dat alle boord waardes laer as 1.5 gehad het, wat daarop dui dat die gronde versteurd is. Die konvensioneel bestuurde appelkoosboord het die hoogste MI waarde gehad met ʼn vlak van 1.48. Die waarde vir die PPI was die hoogste in organies bestuurde appelkoosboorde. Alle boord gronde is geleë binne kwadrant B van die Fauna Analiseerder, wat dui op verryking met struktuur. Met betrekking tot die diversiteit, spesie-rykheid en egaligheid van die verspreiding van families, het konvensionele appelkoos grond die hoogste spesierykheid, terwyl die gronde van die organiese appelboord die mees egalige familie verspreiding vertoon het. Verskillende bestuurspraktyke nie toon nie merkbare verskille in die gemeenskap samestelling en struktuur nie. Die spesie-rykheid van Fynbos gronde is vergelykbaar met dié van sagtevrugte-boorde. Monsters is geneem van agt verskillende grondeoppervlak-behandelings in ‘n appelboord in die Grabouw area. Die behandelings is gekombineer volgens die grond toediening wat dit ontvang het (chemiese beheer van dekgewasse en onkruid, deklaag en ‘n deklaag + effektiewe mikro- IX organismes). Bakterievoedende nematodes was dominant in elke grondoppervlak-behandeling, met die minste teenwoordig in die behandelings wat chemiese beheer van die dekgewasse en onkruid ontvang het. Behandelings wat chemiese beheer van die dekgewasse en onkruid ontvang het, het ook hoër vlakke van fungivore in vergelyking met die ander behandelings. ʼn Hoë aantal Rhabditidae het voorgekom in grondmonsters van die deklaag en die deklaag + EM (effektiewe mikro-organismes) behandeling persele, terwyl ʼn groot aantal Aphelenchidae voorgekom het in chemiese beheer persele. Die predatoriese familie, Ironidae, het slegs voorgekom in persele wat die deklaag + EM behandeling ontvang het. Sterk assosiasies bestaan tussen grond behandeling en nematode families wat in die grond teenwoordig was. Die chemiese beheer behandeling het die hoogste MI waarde getoon, terwyl waardes vir die ander behandelings laer en gelyk was. Die fauna analise het daarop gedui dat die deklaag en chemiese beheer binne kwadrant A is en dus verryk, maar ook ongestruktureerd is. Die deklaag + EM behandeling het binne kwadrant B geval wat aandui op toestande van verryking en struktuur wat 'n goeie algehele grondtoestand tot gevolg gehad het. Al die stelsels is oorbruggingsweë wat oorheers was deur bakteriële ontbinding. Kontroversieel, het persele wat chemiese beheer van die dekgewasse en onkruid ontvang het, die hoogste spesierykheid van al drie behandelings getoon asook die hoogste vlak van diversiteit volgens die Simpson-indeks. Slegs die dekgewasse en onkruid is chemies behandel, nie die grond nie, en dus kan die grond as onversteurd beskou word en die resultate wat verkry is in die studie verklaar. Duidelike verskille in die nematode gemeenskap struktuur en samestelling is waargeneem tussen die verskillende grond behandelings in appel boorde.

Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2007. / Small farm dams (< 20 ha) in the Western Cape Province provide adequate water conditions for intensive cage production of rainbow trout (Oncorhynchus mykiss). A major environmental concern of cage aquaculture, however, is the high inputs of nutrients via commercial diets and the subsequent eutrophication of the water source. Eutrophication can result in the degradation of the general water quality (increasing pH levels, oxygen depletion, increased hydrogen sulphide and free ammonia) and shifts in the phytoplankton structure (increased biomass, single species dominance). Deterioration of water quality will affect the success of the fish farming enterprise as well as the performance of irrigation equipment by increasing the risk of clogging and corrosion. Water quality, phytoplankton and zooplankton compositions were monitored at four sites from June 2005 to November 2006 to determine the effects of cage culture on the farm dam environment, its associated biota as well as irrigation water quality. The distribution of nutrients, nitrogen and phosphorus, was mainly influenced by the stratification and mixing regime of the water bodies. Nutrient concentrations increased during the winter mixing period while in the summer months, they seem to settle to the lower part of the water column. Nutrient concentrations of production sites and reference sites were comparable except for the ammonia levels that were significantly higher at the production sites. Phytoplankton corresponded with nutrient availability resulting in high biomass during winter. In terms of biomass, phytoplankton was approximately two times more abundant in production sites compared to reference sites. Assemblage dominance by cyanophytes (Anabaena circinalis, Microcystis spp.) was found more often in production sites, while reference sites were dominated by dinophytes (Ceratium hirundinella, Peridinium spp.). Zooplankton biomass concurred with high phytoplankton biomass in winter. Zooplankton assemblages in production sites sustained much higher biomass. Effects of cage culture on irrigation water quality are evident from increased algal biomass and shifts in species composition. These results indicated that at its present production level, cage culture had impacts on the farm dam environment and irrigation water quality. The most significant evidence was given by increased plankton biomass and single species dominance in production sites. However, these findings can not solely be ascribed to the introduction of aquaculture as various other factors may also contribute to the water quality of these ecosystems.