A series of studies was undertaken at Plastic Lake-1 (PC1) to determine the sources and controls on S cycling in small headwater catchments on the Precambrian Shield in south-central Ontario. Two observations were made about the S cycle in this region: (1) all streams exhibit highly coherent temporal patterns in SO4 concentrations and export, and (2) most catchments exported more SO4 in stream water than is received in bulk deposition during the past 2 decades. Synchronous temporal patterns in annual SO4 concentrations in both upland and wetland-draining streams were related to changes in climate, specifically those factors that determine catchment dryness. The number of days with no stream flow or stream flow below a critical threshold was a good predictor of the average stream SO4 concentration in a particular year. Sulphate chemistry in the PC1 outflow is highly dependent on processes occurring in a conifer <i>Sphagnum</i> swamp located immediately upstream of the chemical sampling station. Hydrologic inputs to the swamp during the summer determine whether S is retained or released from peat on an annual basis. Drying and re-wetting of <i>Sphagnum</i>-derived peat caused a substantial increase in soluble SO4 in laboratory experiments, which was slightly enhanced at higher temperature, but alternating moisture conditions had no immediate effect on <i>Sphagnum</i>. Despite large inter-annual changes in SO4 release, over the long-term (<i>i. e. </i> 20-years) SO4 inputs and exports from the swamp are in approximate balance. In contrast, the upland portion of PC1 (<i>i. e. </i> PC1-08) consistently exports more SO4 than is input in bulk deposition in every year of record. Even when inputs are increased to account for potential underestimates in dry deposition or weathering, the majority of catchments in this region exhibit net export in many years. Two internal sources are suggested to account for negative budgets: desorption and mineralization. Adsorption/desorption reactions respond directly to changes in SO4 input concentration, and lysimeter data indicate the importance of these processes for buffering short-term changes in SO4 concentration in LFH percolate. Desorption may be the primary direct response of upland soil to decreasing SO4 inputs in deposition and may substantially extend the period of net SO4 export in catchments that have large adsorbed SO4 pools such as PC1. However, the adsorbed pool may be sustained by continuous net release from mineralization, and should also be considered in budget calculations. Mineralization was shown to be responsive to drying and re-wetting events and temperature, although results varied among different materials. Sulphate release from mineral soil did not appear to be influenced by changing moisture, temperature or deposition chemistry in laboratory experiments, although adsorption/desorption reactions may have largely masked small changes in SO4 release <i>via</i> mineralization. The magnitude of organic S storage in mineral soil indicates that this pool could be an important source of export over the long-term. While it is unknown why (or if) mineralization is a net source of SO4 to drainage streams, changes in climate and/or deposition could potentially influence SO4 release from organic compounds. Soil moisture and temperature are important controls on microbial processes in soil, and changes in climate that bring about changes in soil moisture or temperature conditions could affect decomposition and mineralization processes. Similarly, historically high inputs of S and N in deposition may have brought about slow shifts in litter quality (<i>i. e. </i> decreased C:N, C:S) which could also potentially influence decomposition and mineralization rates. In order to predict the future response of surface water chemistry to changes in SO4 (and N) deposition, it is important to consider not only the magnitude of S pools in soil, but also the potential for SO4 cycling between pools. Likewise, models that predict changes in stream SO4 by adsorption isotherm data alone will underestimate the importance of desorption unless the potential for continual replenishment of the adsorbed pool through the relatively slower process of mineralization is also considered. In general, predictions of recovery from S deposition can only be made from a complete understanding of S pools, transformations, and the effects of climate, which are superimposed upon the long-term trend in deposition.

A series of studies was undertaken at Plastic Lake-1 (PC1) to determine the sources and controls on S cycling in small headwater catchments on the Precambrian Shield in south-central Ontario. Two observations were made about the S cycle in this region: (1) all streams exhibit highly coherent temporal patterns in SO4 concentrations and export, and (2) most catchments exported more SO4 in stream water than is received in bulk deposition during the past 2 decades. Synchronous temporal patterns in annual SO4 concentrations in both upland and wetland-draining streams were related to changes in climate, specifically those factors that determine catchment dryness. The number of days with no stream flow or stream flow below a critical threshold was a good predictor of the average stream SO4 concentration in a particular year. Sulphate chemistry in the PC1 outflow is highly dependent on processes occurring in a conifer <i>Sphagnum</i> swamp located immediately upstream of the chemical sampling station. Hydrologic inputs to the swamp during the summer determine whether S is retained or released from peat on an annual basis. Drying and re-wetting of <i>Sphagnum</i>-derived peat caused a substantial increase in soluble SO4 in laboratory experiments, which was slightly enhanced at higher temperature, but alternating moisture conditions had no immediate effect on <i>Sphagnum</i>. Despite large inter-annual changes in SO4 release, over the long-term (<i>i. e. </i> 20-years) SO4 inputs and exports from the swamp are in approximate balance. In contrast, the upland portion of PC1 (<i>i. e. </i> PC1-08) consistently exports more SO4 than is input in bulk deposition in every year of record. Even when inputs are increased to account for potential underestimates in dry deposition or weathering, the majority of catchments in this region exhibit net export in many years. Two internal sources are suggested to account for negative budgets: desorption and mineralization. Adsorption/desorption reactions respond directly to changes in SO4 input concentration, and lysimeter data indicate the importance of these processes for buffering short-term changes in SO4 concentration in LFH percolate. Desorption may be the primary direct response of upland soil to decreasing SO4 inputs in deposition and may substantially extend the period of net SO4 export in catchments that have large adsorbed SO4 pools such as PC1. However, the adsorbed pool may be sustained by continuous net release from mineralization, and should also be considered in budget calculations. Mineralization was shown to be responsive to drying and re-wetting events and temperature, although results varied among different materials. Sulphate release from mineral soil did not appear to be influenced by changing moisture, temperature or deposition chemistry in laboratory experiments, although adsorption/desorption reactions may have largely masked small changes in SO4 release <i>via</i> mineralization. The magnitude of organic S storage in mineral soil indicates that this pool could be an important source of export over the long-term. While it is unknown why (or if) mineralization is a net source of SO4 to drainage streams, changes in climate and/or deposition could potentially influence SO4 release from organic compounds. Soil moisture and temperature are important controls on microbial processes in soil, and changes in climate that bring about changes in soil moisture or temperature conditions could affect decomposition and mineralization processes. Similarly, historically high inputs of S and N in deposition may have brought about slow shifts in litter quality (<i>i. e. </i> decreased C:N, C:S) which could also potentially influence decomposition and mineralization rates. In order to predict the future response of surface water chemistry to changes in SO4 (and N) deposition, it is important to consider not only the magnitude of S pools in soil, but also the potential for SO4 cycling between pools. Likewise, models that predict changes in stream SO4 by adsorption isotherm data alone will underestimate the importance of desorption unless the potential for continual replenishment of the adsorbed pool through the relatively slower process of mineralization is also considered. In general, predictions of recovery from S deposition can only be made from a complete understanding of S pools, transformations, and the effects of climate, which are superimposed upon the long-term trend in deposition.

The purpose of this paper was to examine the competitiveness of the South African sugar industry relative to the top ten exporters of the product, namely Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium and the United States of America. Different techniques were used in the study to ensure that the main objective of the study was achieved. Three popular indices, namely the Balassa Revealed Comparative Advantage (RCA#) Index, the Net Export Index (NXi) and the Relative Revealed Comparative Trade Advantage (RTA) Index were used to compare the competitiveness of the top ten sugar exporting countries including South Africa. The Trade Potential Index was also applied in the study to investigate markets that South Africa could use to increase its exports. Time series data collected on the trade map and the Food and Agricultural Organization of the United Nations were used for the analysis of the markets by using an Excel spreadsheet. The results of the study showed that South Africa has a trade competitive advantage against the majority of the countries considered. South Africa's competitive performance was surpassed by that of Brazil, which was the strongest trader of sugar, followed by Thailand and China. The remaining seven countries (Mexico, Belgium, Netherlands, Canada, Germany, USA and China) were all exceeded by the South African sugar industry. The top potential markets that South Africa could exploit to increase its exports were identified with the use of the Trade Potential Index (TPI). The countries that were identified were selected by calculating the scores, comparing tariffs imposed by these markets to the exporters of sugar and looking at the concentration of the markets that supply these potential markets. The United States of America, Lesotho, Democratic Republic of Congo, Malawi and Egypt were identified as the top five countries that South Africa could exploit for its sugar exports. South Africa has trade agreements with the majority of these countries which assist the country in obtaining preferential agreements when exporting its products to these countries. Recommendations were made that could help the sugar industry to grow its competitiveness. / Inhloso yaleliphepha bekukuhlola kuncintisana kwemboni yashukela yaseNingizimu Afrika nayicatsaniswa nebatfumeli ngaphandle labasembili labalishumi balomkhicito, lekuyiBrazil, iThailand, iNetherlands, iMexico, iChina, iGermany, iCanada, iFrance, iBelgium ne-United States of America. Kusetjentiswa emasu lahlukene kulesifundvo kucinisekisa kutsi inhloso lenkhulu yesifundvo iyaphunyelelwa. Kusetjentiswe ema-indice, lekuyi-Balassa Revealed Comparative Advantage (RCA#) Index, i-Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index kucatsanisa kuncintisana kwalamave lasembili lalishumi lakhicita shukela kufaka ekhatsi eNingizimu Afrika. I-Trade Potential Index nayo isetjentisiwe kulesifundvo kuphenya timakethe letingasetjentiswa yiNingizimu Afrika kute ikhulise kutfumela ngaphandle kwayo lomkhicito washukela. Idatha yeluchungechunge lwesikhatsi legcogcwe kulibalave lekuhwebelana kanye naseNhlanganweni Yekudla Neyetekulima yaMhlab'uhlangene isetjentisiswe kuloluhlatiyo lwetimakethe ngekusebentisa si-spreadsheet se-Excel. Imiphumela yesifundvo ikhombise kwekutsi iNingizimu Afrika inekusitakala ngekuncintisana ekuhwebeni nayicatsaniswa nelinyenti lalamave lamanyenti lahlatiyiwe. Kusebenta kwekuncintisana kweNingizimu Afrika kundlulwe kusebenta kweBrazil, lebeyingumhwebi lomkhulu washukela, ilandzelwe yiThailand kanye neChina. Lamave lasikhombisa lasele (iMexico, iBelgium, iNetherlands, iCanada, iGermany, i-USA neFrance) onkhe andlulwe yimboni yashukela yaseNingizimu Afrika. Timakethe letingaba khona letiphambili leti iNingizimu Afrika ingatisebentisa kukhulisa kutfumela ngaphandle kwayo tibonwe ngekusebentisa iTrade Potential Index (TPI). Emave laboniwe akhetfwe ngekubala imiphumela, kucatsanisa ematharifu lafakwe nguletimakethe kubatfumeli bangaphandle bashukela nekubuka kulokucocana kwetimakethe lephakela letimakethe letingaba khona. I-United States of America, iLesotho, iDemocratic Republic of Congo, iMalawi ne-Egypt abonwe njengemave lasembili lasihlanu langasetjentiswa yiNingizimu Afrika kutfola ngaphandle shukela wayo. INingizimu Afrika inetivumelwano tekuhwebelana nelinyenti lalamave lokusita lelive ekutfoleni tivumelwano tekubekwa ngembili nangabe kutfunyelwa ngaphandle imikhicito yayo kulamave. Tiphakamiso letingasita imboni yashukela kukhulisa kuncintisana kwayo tentiwe. / Inhloso yalo mbhalo wocwaningo kwabe kuwukucubungula nokuhlaziya amandla okuncintisana ngempumelelo kwemboni kashukela yaseNingizimu Afrika uma iqhathaniswa namazwe ayishumi ahamba phambili emhlabeni ekuthumeleni imikhiqizo kashukela emazweni angaphandle, okuyi-Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium kanye neMelika (USA). Kulolu cwaningo kwasetshenziswa izindlela ezihlukahlukene ngenhloso yokuqinisekisa ukufezekiswa kwenjongo enkulu yocwaningo. Kwasetshenziswa izinkomba-simo ezintathu ezidumile futhi okuyizona ezisetshenziswa kakhulu, okuyi-Balassa Revealed Comparative Advantage (RCA#) Index, Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index ukuqhathanisa amandla okuncintisana ngempumelelo kwamazwe ayishumi ahamba phambili emhlabeni ekuthumeleni ushukela emazweni angaphandle, kubandakanya neNingizimu Afrika. I-Trade Potential Index yasetshenziswa futhi nayo kulolu cwaningo ukuphenya nokucubungula izimakethe ezingasetshenziswa yiNingizimu Afrika ukukhulisa inani lemikhiqizo yayo ethunyelwa emazweni angaphandle. Idatha eqoqwe ochungechungeni lwamaqophelo alandelana ngokwesikhathi ebalazweni lokuhwebelana kanye naseNhlanganweni Yokudla NezolimoyeNhlangano Yezizwe yasetshenziselwa ukuhlaziya izimakethe ku-Excel spreadsheet. Imiphumela yocwaningo yabonisa ukuthi iNingizimu Afrika isesimweni esikahle futhi inamandla angcono okuncintisana ngempumelelo kwezohwebo uma iqhathaniswa neningi lamazwe acutshungulwayo. Amandla eNingizimu Afrika okuncintisana ngempumelelo adlulwa yilawo e-Brazil, okuyizwe elinamandla kakhulu futhi elihamba phambili kwezokuhwebelana ngoshukela, kulandele i-Thailand kanye ne-France. Imboni kashukela yaseNingizimu Afrika inamandla angaphezulu kwawo wonke lawa amanye amazwe asele ayisikhombisa (okuyi-Mexico, Belgium, Netherlands, Canada, Germany, USA kanye ne-China). Amazwe ahamba phambili angasetshenziswa yiNingizimu Afrika ekukhuphuleni umthamo wemikhiqizo yayo ethunyelwa emazweni angaphandle ahlonzwa ngokusebenzisa i-Trade Potential Index (TPI). Lawo mazwe ahlonziwe akhethwe ngokubala inani lamaphuzu, ukuqhathanisa intela yempahla ekhokhiswa yilawo mazwe emazweni angaphandle athumela ushukela kanye nokubheka ubuningi bamazwe athumela imikhiqizo yawo kulawo mazwe angasetshenziswa yiNingizimu Afrika ukukhulisa umthamo wemikhiqizo yawo ethunyelwa emazweni angaphandle. I-USA, Lesotho, Democratic Republic of Congo, Malawi kanye ne-Egypt ahlonzwa njengamazwe aphuma phambili iNingizimu Afrika engathumela kuwona ushukela. INingizimu Afrika inezivumelwano zokuhwebelana neningi lalawa mazwe, okuyizivumelwano eziyilekelelayo ekutholeni izivumelwano ezizokwenza ibhekelelwe kangcono futhi icatshangelwe uma ithumela imikhiqizo yayo kulawa mazwe angaphandle. Kwenziwa izincomo ezingayilekelela imboni kashukela ukuthi ikwazi ukukhulisa amandla ayo okuncintisana ngempumelelo. / Agriculture and  Animal Health / M. Sc. (Agriculture)

The South African citrus fruit industry faces enormous challenges in the global markets, such as an increasing demand for higher quality citrus fruits, as well as increasing fierce competition from the southern hemisphere citrus producing countries. Its long history of global integration makes it highly sensitive to international developments, as well as domestic ones. The purpose of the study is to investigate the competitiveness of the South African citrus fruit industry relative to its southern hemisphere competitors – namely, Argentina, Australia, Uruguay, Chile and Peru. Both local and international literature on the citrus fruit industries was used as part of the analysis. In addition to this, a variety of methods and techniques were applied. These included the three well-recognised indices which were used to calculate the competitive indices of various citrus fruit product categories – namely, the Balassa Revealed Comparative Advantage (RCA#) index, the Net Export index (NXi) and the Relative Revealed Comparative Trade Advantage (RTA) index. Time series data on South African and southern hemisphere major producing countries’ citrus fruit imports and exports were used to calculate the competitiveness indices using Excel spreadsheets. A structured questionnaire was also used to collect both qualitative and quantitative data of expert views from key industry stakeholders. Data collected were analysed using Excel spreadsheets and the Porter methodology. The competitiveness analysis of this study clearly pointed out that the South African citrus fruit industry reveals more competitive advantage in some citrus fruit products than its southern hemisphere counterparts. The results of the RCA#, NXi and RTA indices analyses clearly showed that the domestic industry has a stronger and relatively higher revealed competitive advantage in three citrus fruit product categories – namely, oranges, grapefruit and grapefruit juice than its southern hemisphere competitors. However, its orange competitiveness decreases when moving from primary orange to orange juice. This means that the value-adding opportunities are still lacking in the orange sub-sector. One possible reason for this could be the high rates of return recorded for farm-level applications of technology for most primary orange commodities. This study identified the availability of skilled employees, quality of unskilled labour, cost of doing business in the industry, services from financial institution, electricity supply, land reform and some other government policies, such as trade policy, labour policy, BEE policy iv and tax system as the major factors impeding the competitiveness of the industry. The list also included the current climatic conditions, high incidences of HIV/AIDS and crime, economic instability and the cost of technology and infrastructure in the industry. Despite the challenges mentioned above, quality of skilled labour; general level of development and quality of infrastructure and technology in the industry; quality of soils; the availability of scientific research institutions and the collaboration of the industry with these institutions; availability and quality of local suppliers of primary inputs; and market information flow were found to have a positive influence on the competitiveness of the industry. In order for the industry to enhance its competitiveness, a number of recommendations and strategies are suggested at the end of this study. / Agriculture and  Animal Health / M.Sc. (Agriculture)

The South African citrus fruit industry faces enormous challenges in the global markets, such as an increasing demand for higher quality citrus fruits, as well as increasing fierce competition from the southern hemisphere citrus producing countries. Its long history of global integration makes it highly sensitive to international developments, as well as domestic ones. The purpose of the study is to investigate the competitiveness of the South African citrus fruit industry relative to its southern hemisphere competitors – namely, Argentina, Australia, Uruguay, Chile and Peru. Both local and international literature on the citrus fruit industries was used as part of the analysis. In addition to this, a variety of methods and techniques were applied. These included the three well-recognised indices which were used to calculate the competitive indices of various citrus fruit product categories – namely, the Balassa Revealed Comparative Advantage (RCA#) index, the Net Export index (NXi) and the Relative Revealed Comparative Trade Advantage (RTA) index. Time series data on South African and southern hemisphere major producing countries’ citrus fruit imports and exports were used to calculate the competitiveness indices using Excel spreadsheets. A structured questionnaire was also used to collect both qualitative and quantitative data of expert views from key industry stakeholders. Data collected were analysed using Excel spreadsheets and the Porter methodology. The competitiveness analysis of this study clearly pointed out that the South African citrus fruit industry reveals more competitive advantage in some citrus fruit products than its southern hemisphere counterparts. The results of the RCA#, NXi and RTA indices analyses clearly showed that the domestic industry has a stronger and relatively higher revealed competitive advantage in three citrus fruit product categories – namely, oranges, grapefruit and grapefruit juice than its southern hemisphere competitors. However, its orange competitiveness decreases when moving from primary orange to orange juice. This means that the value-adding opportunities are still lacking in the orange sub-sector. One possible reason for this could be the high rates of return recorded for farm-level applications of technology for most primary orange commodities. This study identified the availability of skilled employees, quality of unskilled labour, cost of doing business in the industry, services from financial institution, electricity supply, land reform and some other government policies, such as trade policy, labour policy, BEE policy iv and tax system as the major factors impeding the competitiveness of the industry. The list also included the current climatic conditions, high incidences of HIV/AIDS and crime, economic instability and the cost of technology and infrastructure in the industry. Despite the challenges mentioned above, quality of skilled labour; general level of development and quality of infrastructure and technology in the industry; quality of soils; the availability of scientific research institutions and the collaboration of the industry with these institutions; availability and quality of local suppliers of primary inputs; and market information flow were found to have a positive influence on the competitiveness of the industry. In order for the industry to enhance its competitiveness, a number of recommendations and strategies are suggested at the end of this study. / Agriculture and  Animal Health / M. Sc. (Agriculture)

This thesis focuses on the theoretical conception of the Balance of Payment, its method of adjustment and stress the development of the Czech republic's Balance of Payment in period 2000 -- 2010 via analytical-descriptive approach. It defines its basic terms practical relations within framework of the horizontal and vertical outlook. Thesis's Attention is spread out between status and flow quantity. Thesis is also consist of three boxes that contain a short profile of intertemporal approach to the Common Account, sustainability of investment position and excursion to the essential theories of foreign currency exchange rate that is related to the Balance of payment tight. The end is dedicated to the "traditional" indicators of external equilibrium of the Czech republic in pre-monetary crisis era and in the present.