Tesi sul tema "Biological diversity – Economic aspects"
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Gerber, Nicolas Economics Australian School of Business UNSW. "Biodiversity measurement, species interactions and sustainability". Awarded by:University of New South Wales. School of Economics, 2006. http://handle.unsw.edu.au/1959.4/26796.
Testo completoBush, Glenn K. "The economic value of Albertine Rift Forests : applications in policy and programming". Thesis, University of Stirling, 2009. http://hdl.handle.net/1893/2309.
Testo completoMoran, Dominic. "Investing in biological diversity : economic valuation and priorities for development". Thesis, University College London (University of London), 1997. http://discovery.ucl.ac.uk/1317651/.
Testo completoCrook, Carolyn. "Biodiversity prospecting agreements evaluating their economic and conservation benefits in Costa Rica and Peru /". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ58978.pdf.
Testo completoOmokanye, Akim Tunde, University of Western Sydney, of Science Technology and Environment College e Centre for Horticulture and Plant Sciences. "Biological and economic evaluation of maize-based cropping systems for Nigerian smallholders". THESIS_CSTE_HPS_Omokanye_A.xml, 2004. http://handle.uws.edu.au:8081/1959.7/797.
Testo completoDoctor of Philosophy (PhD)
Schelhas, John William Jr. "Socio-economic and biological aspects of land use adjacent to Braulio Carrillo National Park, Costa Rica". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185452.
Testo completoScarr, Lowell Martin. "Assessing the value of public investment into biological control research for invasive alien plants : the ARC PPRI Weeds Research Division". Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/d1020604.
Testo completoVan, der Westhuizen Robert Rolfe. "A genetic analysis of biological and economic efficiency of post-weaning feedlot performance in beef cattle". Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50249.
Testo completoENGLISH ABSTRACT: It is generally accepted that feed intake and growth (gain) are the most important economic components when calculating profitability in a growth test or feedlot. Feeding cost of animals is a major determinant of profitability in livestock production enterprises. Genetic selection to improve feed efficiency aims to reduce the cost of feeding in beef cattle production and thereby improve profitability. The objective of this study was to define a clear selection objective to enable South African beef breeders and especially the feedlot industry to select for post-weaning growth or feedlot performance and to identify factors influencing profitability in a feedlot environment. Because of the recording of individual feed intake and weight gain values in the South African Agricultural Research Councils' centralized growth tests, it was also possible to calculate a phenotypic value for feedlot profitability (R-value) for each bull tested in a centralized growth test. (Co)variances, using multitrait as well as random regression models, for and between feedlot profitability, weaning weight and other production, reproduction and efficiency traits were estimated. Residual feed intake (RFI) and feed conversion ratio (FCR) as efficiency traits were also compared to growth (average daily gain (ADG), weaning weight (WW) and shoulder height (SHD)), reproductive (scrotum circumference (SCR)) and profitability (feedlot profitability) traits measured in growth tests of young Bonsmara bulls. Consequently, a single post-weaning growth selection index value based on the economic and breeding values of different selection criteria related to feedlot profitability was composed. (Co)variance components, heritabilities and genetic correlations for and between initial weight (lW), final weight (FW), total feed intake (FI) and shoulder height (SHD) were estimated through the use of multitrait restricted maximum likelihood (REML) procedures. These breeding values (EBV s) were then used in a selection index to calculate a single economical value for each animal. This economical value is an indication of the gross profitability value or gross test value (GTV) of the animal in a post-weaning growth test. The heritability estimate of 0.36 for R-value, obtained from the multitrait analysis, shows that this trait is genetically inherited and that it can be selected for. The heritability for R-value obtained from the single trait random regression model varied between 0.57 and 0.62. The genetic correlations between the R-value and the other traits, obtained from the multitrait analysis, varied from negligible to high. The heritability estimated for FCR was 0.34 and for RFl 0.31 with a genetic correlation estimate of 0.75 between the traits. The estimated genetic correlation between profitability (R-value) and FCR and RFl were -0.92 and -0.59, respectively. The genetic correlation estimate of -0.92 between FCR and R-value is largely due to the part-whole relationship between these two traits. This is also shown in their genetic trends. The genetic correlations and expected correlated responses between RFl and FCR with R-value suggest that indirect selection for R-value through the direct selection for FCR and/or RFl will result in slower genetic progress in Rvalue than direct selection for R-value. However, where the R-value cannot be calculated and/or where direct selection for R-value is not possible, it would be better to select indirectly for R-value through the use of FCR rather than RF!. Consequently, a regression equation was developed (with an R2 of 0.82) to estimate a feed intake value for all performance-tested Bonsmara bulls which were group fed and whose feed intakes were unknown. These predicted feed intake values made it possible to calculate a feedlot or post-weaning growth profitability value (R-value) for all tested bulls even where individual feed intakes were unknown. Subsequently, an R-value for each bull was calculated in a favourable economic environment (FEE), an average economic environment (AEE) and in an unfavourable economic environment (VEE). The high Pearson and Spearman correlations between the EBV s based on AEE and the other two environments suggested that the average economic environment could be used to calculate EBVs for R-value or feedlot growth profitability. It is therefore not necessary to change the carcass, weaner or feed price on a regular basis to account for possible re-rankings based on R-value EBVs. Heritabilities for lW, FW, Fl and SHD were 0.41, 0.40, 0.33 and 0.51, respectively. The highest genetic correlations between these traits were the 0.78 (between lW and FW) and 0.70 (between Fl and FW). GTV values varied between -R192.l7 and R231.38, with an average of R9.31. The Pearson correlations between EBVs (for production and efficiency traits) and GTV range from -0.51 to 0.68. The lowest correlation (closest to zero) was 0.26 between the Kleiber ratio (KLB) and GTV. Correlations of 0.68 and -0.51 were estimated between average daily gain (ADG) and GTV and feed conversion ratio (FCR) and GTV, respectively. The heritabilities of the different traits included in the selection index suggest that it is possible to select for a GTV. The selection index can benefit feedlotting In selecting offspring of bulls with high GTV values to maximize profitability. The Pearson and Spearman correlations between the R-value EBVs and the index values (GTV) were very high (0.97). This high correlation of 97% indicates that it is not important which method is used to calculate a genetic post-weaning growth of feedlot profitability value. The selection index value is, however, more simplified than the feedlot profitability with less assumption. Therefore, it is recommended that the post-weaning selection index value be used as a selection objective in breeding programmes to improve post-weaning growth profitability rather than the more complex feedlot profitability value.
AFRIKAANSE OPSOMMING: 'N GENETIESE ANALIESE VAN DIE BIOLOGIESE EN EKONOMIESE DOELTREFFENTHEID VAN NASPEENSE GROEI IN VLEISBEESTE IN DIE VOERKRAAL: Dit word algemeen aanvaar dat voerinname en groei die twee ekonomies mees belangrike komponente in die berekening van 'n naspeense groei- of voerkraalwinsgewindheidswaarde is. Voerkostes is 'n bepalende faktor van winsgewindheid in enige lewendehawe boerderypraktyk. Seleksie om voerdoeltreffendheid te verbeter, verminder dus die voerkostes in vleisbeesproduksie en gevolglik 'n verhoging in die winsgewindheid. Die doelwit van die studie was om faktore te identifiseer wat 'n invloed op winsgewindheid in die voerkraaiomgewing het asook om 'n duidelike seleksiedoelwit te formuleer wat die Suid- Afrikaanse vleisbeesteiers en veral die voerkraalbedryf instaat sal kan stelom vir naspeense groeidoeltreffendheid ofvoerkraalwinsgewindheid te selekteer. As gevolg van die aantekening en rekordhouding van weeklikse individuele voennnames en gewigstoenames van alle prestasiegetoetsde bulle, in 'n gesentraliseerde groeitoets deur die Suid- Afrikaanse Landbou Navorsingsraad getoets, was dit moontlik om vir elk van hierdie bulle 'n fenotipiese voerkraalwinsgewindheidswaarde (R-waarde) te kon bereken. (Ko)variansies is vir en tussen voerkraalwinsgewindheid, speengewig en ander produksie-, reproduksie- en doeltreffendheidseienskappe bereken deur van meereienskap en ewekansige regressie modelle gebruik te maak. Twee doeltreffendheidseienskappe naamlik residuele voerinname (RFI) en voeromsetverhouding (FCR) is ook met groei (gemiddelde daaglikse toename (ADG), speengewig (WW) en skouerhoogte (SHD)), reproduksie (skrotumomvang (SCR)) en winsgewindheidseienskappe (voerkraalwinsgewindheid (R-waarde)) vergelyk, om sodoende te bepaal watter een die mees geskikte eienskap is om indirek vir voerkraalwinsgewindheid of groei, gebaseer op teeltwaardes en ekonomiese waardes vir die verskillende eienskappe, wat 'n invloed op naspeense groei winsgewindheid het, gestruktueer. (Ko)variansiekomponente, oorerflikhede en genetiese korrelasies vir en tussen begingewig (lW), eindgewig (FW), voerinname (FI) en skouerhoogte (SHD) is bereken deur van 'n meereienskap (REML) ontleding gebruik te maak. Hierdie teelwaardes (EBVs) is vervolgens in 'n seleksie-indeks gebruik om 'n enkele ekonomies of voerkraal-winsgewindheids seleksie-indekswaarde (GTV) vir elke dier te bereken. Hierdie ekonomiese waarde is 'n aanduiding van die bruto winsgewindheidswaarde ofbruto toetswaarde (GTV) van die dier in 'n naspeentoets. Die oorerflikheid, vanuit die meereienskapontleding vir R-waarde beraam, was 0.36. Hierdie oorerflikheid dui daarop dat die eienskap oorerflik is en dat dit wel moontlik is om daarvoor te selekteer. Die ooreflikhede van R-waarde, voorspel vanuit die enkeleienskap ewekansige regressieontleding varieer tussen 0.57 en 0.62. Die genetiese korrelasie tussen R-waarde en ander eienskappe, vanuit die meereienskap ontleding beraam, varieer tussen weglaatbaar klein tot hoog. Die oorerflikheid van FeR was 0.34 en van RFI 0.31 met 'n genetiese korrelasie van 0.75 tussen die twee eienskappe. Die genetiese korrelasie tussen R-waarde en FeR, en R-waarde en RFI was onderskeidelik -0.92 en -0.59. Die rede vir die hoë negatiewe genetiese korrelasie tussen R-waarde en FeR van -0.92 is omdat dieselfde komponente in die berekening van die twee eienskappe gebruik is. Dit word ook in die genetiese tendense weerspeël. Die genetiese korrelasies en verwagte gekorreleerde responsies tussen R-waarde en FeR, en tussen R-waarde en RFI dui daarop dat stadiger genetiese vordering verkry sal word in R-waarde deur direkte seleksie vir beide FeR en RFI as wat verkry sal word deur die direkte seleksie vir R-waarde. Wanneer 'n R-waarde egter nie bereken kan word nie of waar dit nie moontlik is om direk vir R-waarde te selekteer nie, sal vinniger genetiese vordering in R-waarde gemaak word deur die direkte seleksie vir FeR as vir RF!. 'n Regressievergelyking is geformuleer (met 'n R2 van 0.82) om vir alle prestasiegetoetsde bulle, waar bulle in 'n groep gevoer is en individuele voerinnames onbekend is, 'n voerinnamewaarde te voorspel. Hierdie voorspelde voerinnames maak dit moontlik om vir elke prestasiegetoetsde bul ,'n naspeengroei- of voerkraalwinswaarde (R-waarde) te bereken, al is hulle individuele voerinnames onbekend. Vervolgens is drie verskillende R-waarde vir vleisproduksie vir elke bul bereken naamlik, in 'n gunstige ekonomiese omgewing (FEE), 'n gemiddelde ekonomiese omgewing (AEE) en 'n ongunstige ekonomiese omgewing (VEE). Die hoë Pearson en Spearman korrelasies tussen die EBVs vir R-waarde, bereken in die AEE en die EBVs in die ander twee ekonomiese omgewings, dui daarop dat die AEE gebruik kan word om EBVs vir naspeense groeiof voerkraalwins te bereken. Dit is dus nie nodig om op 'n gereelde grondslag die karkasprys, lewendige speenkalfprys of die voerprys te verander nie. Oorerflikhede, vanuit die meereienskap ontledings VIr lW, FW, FI en SHD verkry, was onderskeidelik 0.41, 0.40, 0.33 en 0.51. Die hoogste genetiese korrelasies tussen die eienskappe was 0.78 tussen lW en FW en 0.70 tussen FI en FW. GTV indekswaardes varieer tussen -Rl92.17 en R231.38 met 'n gemiddelde waarde van R9.31. Die Pearson korrelasies tussen die EBVs van produksie- en doeltreffenheidseienskappe en GTV het tussen -0.51 en 0.68 gevarieer. Die korrelasie naaste aan zero, van 0.26, was die korrelasie tussen GTV en die Kleiber-verhouding. Die korrelasies tussen GTV en ADG, en GTV en FeR was onderskeidelik 0.68 en -0.51. Die oorerflikhede van die verskillende eienskappe wat in die seleksie-indeks ingesluit is, dui daarop dat die indekswaarde weloorerflik is en dat seleksie hiervoor wel moontlik is. Hierdie indekswaarde kan deur die voerkraaiindustrie gebruik word om nageslag van diere met hoë GTV waardes te selekteer om sodoende maksimum wins uit die voerkraai te genereer. Die Pearson en Spearman korrelasies tussen R-waarde EBVs en die indekswaardes (GTV) was besonder hoog (0.97). Hierdie hoë korrelasie dui daarop dat dit geen verskil sal maak watter een van die twee metodes gebruik word in die berekeninge van 'n naspeense groei- of voerkraalwinswaarde nie. Die seleksie-indeks metode is egter minder gekompliseerd met minder aannames as in die geval van die rekeningkundige fenotipiese benadering (R-waarde). As gevolg hiervan, word die naspeense seleksie-indeks waardes (GTV) aanbeveel om te gebruik as 'n teeldoelwit in telingsprogramme om naspeense groei- of voerkraaiwins geneties te verbeter, eerder as die meer gekompliseerde fenotipiese voerkraaiwins (R-waardes) metode.
Gaika, Lindiwe. "Adequacy of existing protected areas in conserving biodiversity at global and regional levels in relation to socio-economic conditions". Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9646_1254305009.
Testo completoAt a meeting of worl leaders at the United Nations Conference on Environment and Development in Rio de Janeiro in 1992, it was recognized that because of the tremendous increase in the size of the global populations (which now is estimated to exceed six billion), there were concerns that global biodiversity was at risk if insufficient land were not put aside for conservation within formal Protected Areas. The primary aim of this study was to compare investment in Protected Areas in relation to socio-economic conditions at global and regional levels.
Olstorpe, Matilda. "Feed grain improvement through biopreservation and bioprocessing : microbial diversity, energy conservation and animal nutrition aspects /". Uppsala : Dept. of Microbiology, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200877.pdf.
Testo completoLaw, Matthew Charles. "Willingness to pay for the control of water hyacinth in an urban environment of South Africa". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1002731.
Testo completoDhanasekaran, Vijaykrishna. "Freshwater fungi biodiversity, origins and molecular taxonomy /". Thesis, Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B32017583.
Testo completoLi, Yan Ting. "Seeking the balance between trade liberalization and cultural diversity in the framework of WTO and UNESCO :some suggestions to China". Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2580115.
Testo completoNqobizitha, Dube. "Economic evaluation of possible loss of Prosopis pods as a result of biological control in the Northern Cape Province, South Africa". Thesis, University of Fort Hare, 2009. http://hdl.handle.net/10353/394.
Testo completoZazini, Novela. "The impact of diversity in reporting on the editorial independence of small-scale regional community newspapers based in the Eastern Cape". Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53123.
Testo completoENGLISH ABSTRACT: Journalism in South Africa has to be looked at in its historical context. South Africa was a country characterised by disparities. The same can be said about the media in this country. Mainstream media concentrated on the priviledged few and projected their views. On the other hand small regional community media aimed at marginalized communities provided a "voice for the voiceless." These small newspapers focused on the disadvantaged, rural and semi-literate communities. As a result of the history of this country, mainstream media neglected the marginalized communities. A need arose for redressing that imbalance and diversifying reporting. Small community newspapers were the means to achieve that. Unfortunately these newspapers fail to attract advertisers for various reasons. A large percentage of the marginalized communities were unemployed and very few could afford to buy newspapers. One copy of a newspaper was shared by between eight (8) and ten (10) people and that meant low circulation figures. The level of literacy was low and those who were literate, had to read to those who could not. The advertising industry was and is still biased and prejudiced against community media. Most small community newspapers died because of these economic factors. This brings about a need for funding of these newspapers. Are funders prepared to pump money without interfering with editorial independence of newspapers? This Assignment sets out to analyse the conflict between the necessity for diversity in reporting (accommodating the previously neglected) and journalistic independence (related to the need for funding). For the purposes of this Assignment, the focus will be on small regional community newspapers in the Eastern Cape, the Border/Kei- area in particular. The purpose of this Assignment is firstly to ascertain whether moves to diversify media/reporting are taking place - an ethical concern. Secondly to establish whether those who fund these newspapers interfere with their content. Various methods of research are used to establish the purpose of the Assignment. Research methodology in use reveals that attempts to diversify the media by focusing on marginalized communities becomes futile. The reason being that those who provide funding directly or indirectly impose their ideas on the newspapers. Small community newspaper then project the ideas of the priviledged people as result of the pressure from funding. It can be concluded that a solution that regards diversity in reporting and editorial independence as ethical principles is necessary (deontological model). That same solution would have to provide consequences that benefit the greatest number of people (utilitarian approach). Such a solution would in essence ensure the survival and sustainability of small regional newspapers and their editorial independence.
AFRIKAANSE OPSOMMING: Joernalistiek in Suid-Afrika moet binne die historiese konteks beskou word. Die land was gekenmerk deur ongelykhede. Dieselfde norm geld vir die media. Die hoofstroom media wat op die kleiner, bevoorregte groep gekonsentreer het, het uiteraard slegs hul siening geprojekteer. Andersyds is die kantlyn "stom" gemeenskappe tog voorsien van 'n stem deur die klein, gemeenskapsgerigte media. Dié klein koerante het gefokus op semi-geletterde, minder bevoorregte inwoners van die landelike gebiede. Dit was juis hierdie kantlyn gemeenskappe wat om historiese redes verwaarloos was. Die behoefte het dus ontstaan vir die regstelling van die wanbalans en 'n diversifisering van verslaggewing. Kleiner gemeenskapskoerante sou ideaal geskik wees om hierdie doel te bereik. Ongelukkidg misluk hulle om verskeie redes om adverteerders te lok. Die hoë werkloosheidssyfer en gepaardgaande armoede in hiedie kantlyngemeenskappe het koerante onbekostigbaar gemaak vir die meerderheid. Een kopie is deur 8-10 mense gedeel. Dit het op sy beurt die sirkulasiesyfer laat daal. Dié wat kon lees, moes voorlees aan die meerderheid ongeletterdes. Die advertensiewese was en is steeds bevoordeeld teen die klein gemeenskapsmedia. Gevolglik kon hierdie projekte in die verlede om verskeie ekonomiese redes nie oorleef nie. Dit op sy beurt plaas die behoefte vir befondsing onder die soeklig. Die vraag ontstaan nou of sodanige befondsers die redaksionele onafhanklikheid van hierdie media sal respekteer? Hierdie tesis poog om 'n analise te maak van die konflik wat onstaan wanneer aan die een kant gepoog word om alle kantlyn groepe te betrek deur diversifisering en aan die ander kant die befondsing wat bekom moet word sonder om joernalistieke onafhanklikheid prys te gee. Vir die doel van hierdie tesis sal die fokus wees op die klein gemeenskapskoerante in die Oos-Kaap, meer spesifiek die Grens/Keigebied. Die primêre doel van die tesis is, eerstens om vas te stelof daar enige diversifisering plaasvind in die joernalistieke/media area - dit is 'n etiese kwessie. In die tweede plek moet vasgestel word of die befondsers inmeng in die inhoud van die ontvangerkoerante. Verskeie vorms van navorsing word gebruik om bogenoemde doelwite te bereik. Navorsingsmetodiek het bewys dat huidige pogings om te diversifiseer sodat kantlyngemeenskappe betrek kan word, misluk. Die rede hiervoor is dat die befondsers - direk of indirek - hul idees, wat uiteraard die bevoorregte gemeenskap weerspieël, afdwing. Die slotsom is dat enige oplossing gebaseer moet wees op beginsels/reëls wat die meerderheid sal bevoordeel. So 'n oplossing sal aanpasbaar moet wees by omstandighede. Dit moet egter ten alle tye die oorlewing en volhoubaarheid van die klein gemeenskapskoerante en hul redaksionele onafhanklikheid, waarborg.
Prinsloo, Shireen. "The distribution and diversity of macroalgae in selected estuaries along the Eastern Cape coast of South Africa". Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1012314.
Testo completoMoore, Bronwyn Ann. "Investigation into the technical feasibility of biological treatment of precious metal refining wastewater". Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002013.
Testo completoDutra, Paula Hebling. "Institution Interaction and Regime Purpose - Considerations Based on TRIPS/CBD". Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1180729582.
Testo completoKehinde, Temitope Olatayo. "Effects of vineyard management and landscape context on taxonomic diversity and interaction networks of flower-visiting insects in the Cape Floristic Region biodiversity hotspot". Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17980.
Testo completoENGLISH ABSTRACT: Both taxonomic diversity and diversity of species interaction networks are experiencing declines as a result of agricultural intensification at habitat and landscape scales. Reversing this trend is a key conservation issue, particularly for important functional groups such as flower-visiting insects and the networks within which they interact. This is of great concern in regions of high conservation priority such as the Cape Floristic Region (CFR), known for its high level of floral and faunal endemism and exceptional species turnover. Holistic approach to conservation in agricultural landscapes involves both preservation of natural land and wildlife friendly management of the farm land to achieve conservation targets. The value of these extensive management approaches is yet to be fully assessed, especially in perennial systems such as vineyards. I examined here the effects of vineyard management and landscape context on species richness and abundance of flower-visiting insects and their species interaction networks. Possible taxon specific effects were verified. I also investigated whether vineyards under organic and conventional management homogenized insect-flower interaction networks and whether vineyards with different management practices vary in patterns of species turnover. I sampled flower-visiting insects and their interactions in organic and conventional vineyards, and in natural reference sites. Inclusion of natural reference sites enabled me to make management recommendations for patches of natural vegetation in CFR agricultural landscape. Statistical models showed taxon-specific benefit of organic farm management, and of landscape (distance to natural habitat). There was benefit to monkey beetles (Scarabaeidae) but not to bees (Apidae). Organic vineyards had a higher number of insect-flower interactions than conventional ones, but vineyards under the two types of management were similar in terms of other important network indices. However, networks of the vineyards were more nested than the natural sites, indicating that they may be potentially more stable to perturbation and random extinctions. Multivariate dispersion tests revealed insect-flower interaction networks were not homogenized by both organic and conventional vineyards across the landscapes. I also found, through additive partitioning, that organic and conventional vineyards were similar in terms of species turnover of bees and flowering plants. The findings of this study provide heuristic value to current debates on the value of vineyard habitats for insect conservation. Both organic and conventional vineyards that promote sustainable management of the non-crop floral vegetation between vineyard rows are potential solutions for conservation of flower-visiting insects and their interactions. Also, attention has to be paid to the quality and connectivity of the natural habitat patches that are within CFR agricultural landscape. Site specific management and assessment of the value of these landscape elements is important. Management approaches such as carefully controlled burning may be beneficial, as the CFR natural vegetation is a fire-driven community.
AFRIKAANSE OPSOMMING: Taksonomiese diversiteit en diversiteit van spesies-interaksie netwerke ondervind beide afnames as gevolg van landboukundige intensifikasie op habitat en landskap skaal. Om die neiging terug te swaai, is ’n sleutel bewaringsaangeleentheid, veral vir belangrike funksionele groepe soos blom-besoekende insekte en die netwerke waarbinne hulle op mekaar inwerk. Dit is van groot kommer in streke met hoë bewaringsprioriteite soos in die Kaapse Floristiese Streek (KFS), bekend vir sy hoë vlak van plant- en dierendemisme en buitengewone spesies kentering. ’n Holistiese benadering tot bewaring van landboukundige landskappe behels beide die bewaring van natuurlike land en natuurlewe-vriendelike bestuur van die plaasgrond om bewaringsdoelwitte te bereik. Die waarde van hierdie ekstensiewe bestuursbenaderings moet nog volledig bepaal word, veral in meerjarige sisteme soos wingerde. Ek het die uitwerkings van wingerdbestuur en landskapsamehang op spesiesrykheid en volopheid van blombesoekende insekte en hulle spesies interaksie netwerke ondersoek. Moontlike takson-spesifieke uitwerkings is nagegaan. Ek het ook ondersoek ingestel of wingerde onder organiese en gebruiklike bestuur ooreenstemmende insek-blom interaksie netwerke met wingerde met verskillende bestuurspraktyke in patroon van spesies kentering gewissel het. Ek het blom-besoekende insekte en hulle interaksies in organiese en konvensionele wingerde, asook in natuurlike verwysingsgebiede gemonster. Insluiting van natuurlike verwysingsgebiede het my in staat gestel om bestuursvoorstelle vir gebiede van natuurlike plantegroei in KFS landboulandskappe voor te stel. Statistiese modelle toon takson-spesifieke voordeel van organiese plaasbestuur en van die landskap (afstand van natuurlike habitat) self. Daar was voordeel vir bobbejaankewers (Scarabaeidae), maar nie vir bye (Apidae) nie. Organiese wingerde het ’n groter getal insek-blom interaksies as konvensionele wingerde gehad, maar wingerde onder beide tipes van bestuur was soortgelyk in terme van ander belangrike netwerk aanduiders. Netwerke van wingerde was egter meer geklomp dan natuurlike gebiede wat aandui dat hulle potensieel meer stabiel betreffende versteuring en lukrake uitsterwings is. Multivariate verspreidingstoetse het aangetoon dat insek-blom interaksie netwerke by beide organiese en konvensionele wingerde oor landskappe nie eenvormig was nie. Ek het ook bevind deur aanvullende verdeling dat organiese en konvensionele wingerde gelykwaardig was in terme van spesies kentering van bye en blomplante. Die bevindings van hierdie studie verskaf heuristise waarde tot huidige debatte oor die waarde van wingerdhabitatte vir insekbewaring. Beide organies en konvensionele wingerde wat volhoubare bestuur van die nie-gewas plantegroei binne wingerdrye bevorder, is moontlike oplossings vir die bewaring van blom-besoekende insekte en hulle wisselwerkings. Bykomend moet aandag gegee word aan die kwaliteit en verbindings van en tussen natuurlike habitat gebiede binne die KFS landboulandskap. Plekspesifieke (plaaslike) bestuur en bepaling van die waarde van hierdie landskapelemente is belangrik. Bestuursbenaderings, soos noukeurig beheerde brand, mag voordelig wees aangesien die KFS natuurlike plantegroei ’n vuurgedrewe gemeenskap is.
Gumede, Halalisani. "The development of a putative microbial product for use in crop production". Thesis, Rhodes University, 2008. http://eprints.ru.ac.za/1352/.
Testo completoJern, Isacsson Gretha, e Robin Emilie Elfsberg. "Rösterna bakom den blågröna vågen och jordbruksrevolutionen - Alternativ livsmedelsproduktion i prat och praktik". Thesis, Malmö universitet, Fakulteten för kultur och samhälle (KS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-22319.
Testo completoSweden's food system faces major challenges such as negative environmental impact and is dependent on importing both food and intermediate goods. Food production, which today is dominated by conventional agriculture, has meant, among other things, depleted soils and exploited resources as well as emissions of toxins. This study aims to compile and compare the scientific research and the public debate regarding alternative food production systems. The study is limited to account for the production systems regenerative agriculture and aquaponic systems. The scientific research regarding regenerative agriculture and aquaponic systems was compiled in a state of knowledge. A qualitative content analysis was performed to identify and compile the public debate about the systems. The public debate concerning alternative food production systems formed the following themes: the coordinating voice, the public voice, the researcher's voice, the operational voice, and the miscellaneous voice. Within these themes, the following six code words were identified: food supply, environmental aspects, economic aspects, social aspects, challenges and opportunities. In our study, we have not formulated any new concepts, however, we have found connections as well as discrepancies and gaps between the public debate and the scientific research.
Tacconi, Luca Economics & Management Australian Defence Force Academy UNSW. "The process of forest conservation in Vanuatu : a study in ecological economics". Awarded by:University of New South Wales - Australian Defence Force Academy. School of Economics and Management, 1995. http://handle.unsw.edu.au/1959.4/38725.
Testo completoMason, Nicholas Craig. "Forging a New Global Commons Introducing common property into the global genetic resource debate". Thesis, University of Canterbury. School of Political Science and Communication, 2004. http://hdl.handle.net/10092/904.
Testo completoGlenk, Klaus. "Economic Valuation of Biological Diversity". Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-AEC2-0.
Testo completoLitvin, Oren. "Heterogeneity and Context-Specificity in Biological Systems". Thesis, 2014. https://doi.org/10.7916/D84T6GHB.
Testo completoOguamanam, Chidi Vitus. "Biological diversity and intellectual property rights : the challenge of traditional knowledge". Thesis, 2000. http://hdl.handle.net/2429/10735.
Testo completoVeiga, Pedro Filipe Duarte Alves da. "Recreational shore fishing in southern Portugal: biological and socio-economic aspects and perspectives for management". Doctoral thesis, 2012. http://hdl.handle.net/10400.1/6800.
Testo completoO problema de sobrepesca que se tem assistido em muitas partes do globo foi, durante muito tempo, apenas associado à pesca comercial, com pouca ou nenhuma atenção dirigida à potencial contribuição da pesca recreativa. Estudos recentes têm demonstrado, no entanto, que o impacto da pesca recreativa em algumas espécies em particular pode ser considerável e que, como tal, avaliações e gestão de recursos que não incluam esta componete podem ser enviesadas e ineficazes na protecção dos recursos. Em Portugal, as primeiras medidas restritivas para a pesca recreativa só recentemente foram implementadas. No entanto, e à semelhança do que se verificou em outros países Europeus, as restrições careceram de suporte científico, dada a escassez de estudos em relação à actividade até ao momento. Este projecto, dirigido à pesca recreativa de costa (PRC) no sul e sudoeste de Portugal, teve como objectivos principais: 1) caracterizar a actividade nas suas vertentes biológica e socioeconómica; 2) avaliar a eficácia e a aceitação da legislação no que diz respeito às várias medidas restritivas; e 3) fazer recomendações que permitam uma melhor gestão e conservação dos recursos costeiros em Portugal. A caracterização da pesca recreativa de costa foi efectuada com recurso a duas metodologias complementares: 1) entrevistas nos locais de pesca, para obtenção de informação sobre as saídas de pesca (p.ex. capturas) e informação socioeconómica; e 2) levantamentos aéreos de distribuição de pescadores, para obtenção de dados de esforço de pesca. A análise das capturas dos pescadores indicou que, no geral, o cumprimento dos limites diários de pesca (10 kg pescador-1 dia-1) foi elevado, com apenas 0.5% dos pescadores entrevistados a excederem este limite. Em relação aos tamanhos mínimos de captura, verificou-se que apenas 11,5% dos peixes retidos pelos pescadores estavam abaixo do tamanho mínimo de desembarque estabelecido por lei. Não obstante, para algumas espécies como o robalo em particular, a percentagem de indivíduos abaixo do limite legal para espécie (36 cm) foi elevada (73%). A nível do impacto da pesca recreativa de costa, verificou-se que as capturas totais anuais estimadas representaram menos de 1% das quantidades desembarcadas pela pesca comercial, para o mesmo período e para espécies capturadas por ambos os tipos de pesca. Uma análise por espécie indicou no entanto que as capturas de sargo legítimo pela pesca recreativa de costa foram consideráveis, correspondendo a 65% dos valores comerciais desembarcados para a mesma espécie (39,4% das capturas totais). Em termos das opiniões dos pescadores em relação a legislação específica para a pesca recreativa, verificou-se que a maioria dos pescadores aceitava a existência de algum tipo de legislação, mas que em geral não concordava com as actuais restrições. Uma grande parte dos pescadores considerou que esta legislação tinha sido desenvolvida sem envolvimento dos mesmos, e que algumas das restrições (p.ex. proibição de pesca nos molhes) careciam de justificação fundamentada. Numa mesma fase foram também investigadas as competições de pesca desportiva de costa a decorrer no sul de Portugal, visando identificar diferenças com a vertente recreativa, e avaliar tendências de longo prazo nas capturas a partir de dados históricos. Verificou-se que em geral as competições de pesca desportiva eram diferentes das da pesca recreativa a nível do número de espécies capturadas e das espécies mais importantes nas capturas (no caso das competições: taínhas e peixe-agulha). Tal diferença atribuiu-se à possibilidade de uma estratégia diferente entre os dois tipos de pescadores relativamente às espécies-alvo. As competições de pesca desportiva foram também caracterizadas por grandes percentagens de espécimens abaixo do tamanho mínimo de desembarque (robalo em particular, 100% abaixo do limite), possivelmente como resultado da utilização de um único tamanho mínimo de 15 cm para todas as espécies. No último estudo, realizaram-se pescas experimentais para testar as taxas de mortalidade póslibertação de três espécies identificadas como importantes na pesca recreativa de costa do sul de Portugal: Safia Diplodus vulgaris; Choupa Spondyliosoma cantharus; e Dourada Sparus aurata. As taxas de mortalidade observadas foram em geral baixas (0-12%). A análise por modelos aditivos generalizados indicou a localização do anzol como o principal predictor da mortalidade, sendo que em 63% das douradas que morreram o anzol se encontrava profundamente alojado no tubo digestivo (estômago, esófago). Estes resultados suportam a decisão de libertar o peixe capturado, voluntariamente ou por medidas restritivas legais. Em suma, neste projecto demonstrou-se que o impacto da pesca recreativa de costa em algumas espécies é significativo, em particular o sargo, devendo ser tido em conta para efeitos de avaliação de gestão de recursos. Foram também realçados vários problemas com a corrente legislação que deveriam ser devidamente analisados de forma a promover medidas de gestão mais adequadas e prevenir futuras situações de incumprimento da lei. Como recomendação final, considera-se que uma monitorização periódica da pesca recreativa em Portugal, nas suas várias modalidades (pesca submarina, pesca embarcada e pesca de costa) e dimensões (biológica e socioeconómica), seria benéfica para um acompanhamento adequado da dinâmica da actividade, e suporte de futuras medidas de gestão.
Fundação para a Ciência e a Tecnologia (FCT)
Perez-Brumer, Amaya Gabriela. "HIV Biomedical Prevention Science and the Business of Gender and Sexual Diversity". Thesis, 2019. https://doi.org/10.7916/d8-n6cg-5t39.
Testo completoGlenk, Klaus [Verfasser]. "Economic valuation of biological diversity : exploring non-market perspectives in the vicinity of the Lore-Lindu National Park in Indonesia's Central Sulawesi Region / vorgelegt von Klaus Glenk". 2006. http://d-nb.info/985524839/34.
Testo completoPark, Seung Eun. "Essays on the Economics of Higher Education and Employment". Thesis, 2019. https://doi.org/10.7916/d8-tg08-fe98.
Testo completoMaake, Mphapantsi Eldred. "Population genetic structure of small holder dairy cattle herds in South Africa using SNP markers". Thesis, 2020. http://hdl.handle.net/10386/3453.
Testo completoThe smallholder dairy sector in South Africa is characterized by a low input production system and poor animal productivity. Research has been carried out to benchmark cow productivity on smallholder dairy herds; however, there is a paucity of information on the current status of breeding practices and the genetic consititution of cattle used in this production system. This information is vital for the development of sound and sustainable breeding programs for SHD production, which can have an enormous positive impact on food security and rural livelihoods. Thus, the aim of this study was to evaluate the levels of genetic diversity and population structure in South African smallholder dairy (SHD) herds using single nucleotide polymorphism (SNP) markers. A total of 192 animals from SHD dairy herds were genotyped using the GeneSeek® Genomic Profiler (GGP) 150K-BeadChip. Four specialized dairy breeds included the Ayrshire(n = 200), Holstein(n = 231), Jersey (n = 224) and Nguni (n = 209) were used as the reference populations. The mean MAF values ranged from 0.30 Ayshire (AYR), Jersey (JER), and Nguni (NGI) to 0.31 Holstein (HOL) and SHD between the populations. There were slight differences in the levels of genetic diversity ranged between 0.39 (JER and NGI) to 0.40 (AYR, HOL, and SHD). A moderate level of inbreeding (0.02) was observed in the SHD population, which results in high genetic diversity among this herds. Principal Component Analysis (PCA) revealed four homogeneous clusters comprising of AYR, HOL, JER, NGI, and a heterogeneous cluster of the SHD. The heterogeneity observed in the SHD population indicates widespread crossbreeding. The model-based cluster analysis corresponded with the PCA and pointed out the predominance of HOL, JER, with marginal gene flow from the AYR and NGI. These results have provided a useful insight into the genetic structure and prevailing breeding practices on South African SHD herds.
National Research Foundation (NRF), Agricultural Research Council (ARC) and University of Limpopo (UL)
Venter, Theo Muller. "The right sized cow for emerging and commercial beef farmers in semi-arid South Africa : connecting biological and economic effeciency". Diss., 2018. http://hdl.handle.net/10500/26004.
Testo completoCow size influences biological efficiency of individual animals, which influences herd composition and stock flow. This in turn influences the economic efficiency of the herd. This research followed the thread from animal size, to biological efficiency, to economic efficiency for beef cattle production under a typical production system in semi-arid South Africa. Cattle were grouped into three groups namely small, medium and large cattle, with mature weights of 300kg, 450kg and 600kg respectively. The net energy requirements of individual cattle were calculated for maintenance, growth, lactation and foetal production, for each of the three sizes. Growth rates, milk yield, reproduction rates, and management practices were assumed from existing research. Next the stock flow for a herd of small, medium and large cattle were calculated from the above. Income and expenses as commonly used in the research area were calculated from the stock flow. Gross profit above allocated costs were subsequently calculated for the three herds under the above-mentioned conditions. When assuming similar reproduction and growth rates for small, medium and large mature cattle, the following results were obtained: more heads of small cattle could be held on a set resource base, but the total live weight of a herd of large cattle that could be held on the same resource base was greater. This was mostly due to proportionately lower maintenance energy requirements in the herd of large cattle. In the simulation in this study, maintenance energy requirements for the herd of large cattle was 71.2%, compared to 72.0% for the herd of medium cattle and 73.1% for the herd of small cattle. Income from the herd of small cattle was the lowest, as less kilograms of beef were available to sell. Allocated costs for the herd of small cattle were the highest, due to a large number of expenses being charged per head of cattle. As a result, the herd of large cattle were more economically efficient than their smaller counterparts. Income above allocated costs for the herds of large, medium and small cattle were R1,182,865, R1,085,116 and R946,012 respectively. Larger cattle generally have a lower reproduction rate under similar conditions. No equation exists that directly links size to reproduction rates, especially considering the vast number of variables that influences reproduction rates. However, in the form of scenarios, it could be calculated that, given a reproduction rate of 80% for mature small cattle, when reproduction rates of large cattle were 24.7% lower than that of small cattle and the reproduction rates of medium cattle were 15.4% lower than that of small cattle, the large and medium herds became less profitable than the small herd. Smaller cattle mature faster than larger cattle which provides the opportunity for early breeding. When small cattle were bred early, at 15 months, at a calving rate of only 44.5% it was more profitable than when the same cows were bred at 24 months. When medium cattle were bred at 15 months, a calving rate of 37.0% was needed to be more profitable than when they were bred at 24 months. Even when the herd of small cattle were bred at 15 months with a reproduction rate of 100%, it could still not match the profitability of the herd of large cattle bred at 24 months given the reproduction rates of all other classes of animals were similar. When the herd of medium cattle were bred at 15 months, at a calving rate of 53.7%, it matched the profit of the herd of large cattle that were bred at 24 months, when the reproduction rates of other classes were equal. Scenarios were considered were feed intake was limited. When feed was limited to a specific amount, smaller cattle were more biologically efficient and cattle with potential for small mature sizes would grow to a larger size than cattle with potential for medium and large mature sizes. When feed was limited by a factor of the calculated energy requirements of small, medium and large cattle, large cattle were more effective. This is because large cattle use proportionately less energy for maintenance, which allows more energy to be allocated to growth, lactation and foetal production. When energy was limited to an amount per unit of metabolic weight, small cattle were more efficient than medium and larger cattle in the growth and production phases. Small, medium and large cattle were equally efficient (or inefficient) in the maintenance and lactation phases. Energy requirements of cattle in South Africa are commonly calculated using the Large Stock Unit (LSU). The LSU typically overestimates energy requirements for cattle, except in the lactation phase. When using the LSU to match small, medium or large cattle to a resource base, the LSU overestimates energy requirements of large cattle proportionately more than that of small and medium cattle. This is excluding the lactation phase, where energy requirements for all three sizes are underestimated and that of large cattle underestimated proportionately more. There are more considerations when matching cow size to managerial practices. A smaller body size is a natural adaptation to a semi-arid environment and this adaptation can be expressed in different ways. The number of animals on a resource base has implications on management practices. Having more heads of cattle on a resource base increases genetic variation of the herd, allowing for genetic progress to be made faster than in herd of fewer cattle.
Agriculture and Animal Health
M.Sc. (Agriculture)
Oliveira, Miguel Tiago Cantiga Lopes de. "The role of artificial reefs to promote biodiversity and sustainability of the ecotourism in Cape Verde: ecological, biological and management aspects". Doctoral thesis, 2016. http://hdl.handle.net/10400.1/8996.
Testo completoThis multidisciplinary study aimed to assess the impact of artificial reefs (ARs) deployment off Santa Maria (Sal Island), to promote biodiversity and sustainability of the ecotourism in Cape Verde.
Maina, Peter Njuguna. "Recognition, measurement and reporting for cap and trade schemes in the agricultural sector". Thesis, 2016. http://hdl.handle.net/10500/21522.
Testo completoColleges of Economic and Management Sciences
D. Phil. (Accounting Science)
Sethusa, Mamadi Theresa. "A molecular phylogenetic study and the use of DNA barcoding to determine its efficacy for identification of economically important scale insects (Hemiptera: Coccoidea) of South Africa". Thesis, 2014. http://hdl.handle.net/10210/11398.
Testo completoScale insects, plant pests of quarantine importance, with specialised anatomy and unresolved phylogenetic relationships, are responsible for major economic losses to South Africa and its trading partners. These losses may reach critical levels if the pests are not timely identified and controlled. They are currently identified based on published keys of adult females, a process that takes three days to two weeks depending on the family and the life stage of interception. In addition, agricultural commodities are often contaminated with different life stages, males or damaged specimen of these pests, making identification difficult or impossible. As a result, shipments of agricultural produce are often rejected and trade disrupted. Furthermore, pest invasions do not only occur by importation via formal channels. At times pests cross boarders as contaminants of undeclared material and may again spread on their own as they naturally expand their range. This expansion may be negatively or positively influenced by other factors such as climate change. Resolving the challenges associated with identification, phylogenetic relationships and the limited knowledge of the effects of climate change on distribution range of scale insects are the main goals of this study. Specifically (i) the development of a rapid method of species identification, (ii) the relationship between and within three major scale insect families the Coccoidea, Diaspididae and Pseudococcidae and (iii) the effect of climate change on the future distribution range of scale insects in South Africa were explored...
Smith, Adriaan Frederik. "Perceived influence of inequality on the career development of emerging adults in South Africa". Diss., 2018. http://hdl.handle.net/10500/26246.
Testo completoIndustrial and Organisational Psychology
M. Com. (Industrial and Organisational Psychology)
Hammer, Michael. "A molecular genetic appraisal of biodiversity and conservation units in freshwater fishes from southern Australia". 2008. http://hdl.handle.net/2440/50448.
Testo completohttp://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339749
Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008
Maas, Bea. "Birds, bats and arthropods in tropical agroforestry landscapes: Functional diversity, multitrophic interactions and crop yield". Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0022-5E77-5.
Testo completoKoutouki, Konstantia. "The placebo effect: international patent law and the protection of traditional plant medicine". Thèse, 2007. http://hdl.handle.net/1866/2772.
Testo completoThe underlying theme of this thesis is the systemic indifference that exists within international intellectual property law towards Indigenous traditional knowledge. In general, there appears to be a widening gap between the importance international law accords to matters of commercial interest and those of a social nature. Indigenous traditional knowledge of medicinal plants is especially disadvantaged in this dichotomous system since it is not only representative of enormous commercial profits but it is also the core of many Indigenous belief and social systems. The crystallization of international law's preoccupation with the effective protection of commercial interests came in the form of the Trade Related Intellectual Property Rights (TRIPS) agreement incorporated into the World Trade Organization (WTO). Two years previously, the Convention on Biological Diversity (CBD) was signed, reflecting international law's perceived dedication to sustainable development and became the first international treaty to address Indigenous traditional knowledge. These two pieces of international law are often seen as balancing the commercial and sustainable development needs of the international economy. Upon further examination however, one is left the impression that the idea of the CBD effectively and successfully defending the needs of sustainable development and Indigenous traditional knowledge against pressure to the contrary from TRIPS and the WTO is simplistic at best. The thesis also explore the role patent law plays in the creation of modern industries, such as the pharmaceutical industry, and how these industries are able, through the power gained via patent law, to influence national and especially international legislation. Equally, it deals with the role patents play in disempowering peoples with Indigenous traditional knowledge of medicinal plants leading to a situation where such knowledge is marginalized along with its bearers. The thesis addresses the institutional shortcomings of the international legal system that allows such a situation to exist and suggests an urgent need to closely examine the social and economic inequalities within the North and South and not just between them. Finally the thesis suggests that international law needs to be guided by the many legal traditions available worldwide and in this particular case perhaps contract law is better suited to the needs of Indigenous traditional knowledge holders.