In der vorliegenden Arbeit wurden die Einflüsse der landwirtschaftlichen Nutzung auf die Struktur und Biomasse von Nematoden entlang eines Tiefengradientens und innerhalb zweier Vegetationsperioden an einem Ackerstandort untersucht. Die Freilandanalyse der Nematodengemeinschaft wies auf ein mit Nährstoffen angereichertes und gestörtes Ökosystem, mit einer geringen Diversität, hin. Entlang des Tiefengradienten bildeten die Nematoden Metacommunities, welche Umweltgegebenheiten wie Nahrungsquellen und abiotischen Faktoren widerspiegeln. Signifikant höhere Biomassen wurden unter Weizen im Vergleich zu Mais als Ackerfrucht beobachtet. Die Streuapplikation induzierte einen „bottom-up“ Effekt mit größeren Biomassen in den niedrigen als in den höheren trophischen Stufen. Die Nematoden Biomassen sowie die faunistischen Indizes (Channel Index, Enrichment Index) zeigten, dass der Kohlenstofffluss im Bakterienkanal des Bodens dominierte. Allerdings deckte das 13C Pulse-Labelling Experiment im Feld auf, dass der Kohlenstofffluss durch die Pilzgemeinschaft sowie die pilzfressenden Nematoden wesentlich höhere Umsatzraten aufweist. In einem 14C-Laborexperiment wurde ein vollständiges Budget des Flusses von wurzelbürtigem Kohlenstoff in das Nahrungsnetz der Nematoden bestimmt. Hierbei wiesen die pflanzenparasitären Nematoden die höchsten 14C-Gehalte innerhalb weniger Tage auf, da sie direkt an den Wurzeln fressen und über die Herbivorenkette den Nährstoffzyklus im Boden eröffnen. / The present research considered the effects of agricultural management practice on the nematode community structure and biomass in three different depths and two successive vegetation periods at an arable field site. The resource quality was manipulated by crop plant and organic amendment, to investigate the major soil carbon pathways based on roots, bacteria and fungi. The nematode community analysis pointed to a highly enriched and disturbed ecosystem with low biodiversity. Along the depth gradient the nematodes formed distinct metacommunities, reflecting resource availability and abiotic environmental factors. Wheat supported significantly greater nematode biomass than maize. The litter amendment induced bottom-up effects, with greater biomass allocation at lower than at higher trophic levels. The biomass of nematode families as well as faunal indices (Channel Index, Enrichment Index) revealed a predominance of the bacterial carbon channel in the arable soil. A 13C pulse-labelling experiment investigating the flux of root- derived C into the soil food web revealed high turnover rates in the fungal carbon pathway. This was evident for soil fungi as well as for fungal-feeding nematodes and contradicts general assumptions of a more active bacterial pathway in arable soils. A laboratory experiment with 14C isotope was used to compile a complete budget for the root-derived carbon in the nematode food web. Here plant-feeding nematodes, which feed on living plant roots, thereby opening the root C cycling into the food web, showed highest amounts of 14C allocation within a few days.

The aim of the study was to investigate the impact of Environmental Education in learners with regard to unacceptable waste dumping which causes land degradation in Mkhondo village. Large parts of the Mkhondo area, including the informal settlement, the location and the local school, are very untidy due to littering by the residents and learners. The situation is contrary to the objectives of the Decade of Education for Sustainable Development (DESD). The study was focused on the impact that Environmental Education as an extracurricular activity would have on the students in reducing or eradicating littering. Data was collected through focus group interviews with the learners and the parents as well as observations. The study revealed that learners showed no concern about the negative impact of disposing of litter inappropriately even after the extra-mural activities on Environmental Education, which indicated that they were not concerned about the environment at school as well as at home. The initiative of Environmental Education was implemented in a short period, hence learners were not yet fully acquainted with the responsibility of taking care of the environment and alleviating littering on the school premises. I therefore recommend that educational campaigns on appropriate solid waste disposal should be initiated in the school and in the community. Further studies should be conducted on how Environmental Education can be integrated in the curriculum as an examinable subject. / Environmental Sciences / M. Ed. (Environmental Education)

<p>Испитивање повезаности особина из перформанс теста назимица са<br />величином легла крмача, обављено је на седам генотипова животиња (чистих<br />раса: дански ландрас, холандски ландрас, немачки ландрас, шведски ландрас и<br />велики јоркшир и програмских мелеза: мелеза чија је мајка ландрас и мелеза чија<br />је мајка велики јоркшир).<br />Фенотипска повезаност особина из перформанс теста (ектеријер, маса на<br />крају теста, старост на крају теста, дневни прираст у тесту, дебљина сланине<br />у слабинском делу, дебљина сланине у леђном делу, дубина МЛД-а, број легла,<br />приплодна вредност назимица процењена селекцијским индексом и проценат меса<br />у трупу) и два основна репродуктивна параметра (број живорођене прасади и број<br />залучене прасади), статистички је анализирана софтверским пакетом &bdquo;Статистика<br />13&ldquo; и &bdquo;SPSS верзија 23&ldquo;. Испитано је постојање/непостојање утицаја сваке<br />појединaчне особине из перформанс теста на репродуктивне особине<br />Није утврђена општа повезаност свих особина перформанс теста и<br />репродуктивних особина<br />Анализиране особине показале су велику зависност од генотипа<br />испитиваних животиња.</p> / <p>Ispitivanje povezanosti osobina iz performans testa nazimica sa<br />veličinom legla krmača, obavljeno je na sedam genotipova životinja (čistih<br />rasa: danski landras, holandski landras, nemački landras, švedski landras i<br />veliki jorkšir i programskih meleza: meleza čija je majka landras i meleza čija<br />je majka veliki jorkšir).<br />Fenotipska povezanost osobina iz performans testa (ekterijer, masa na<br />kraju testa, starost na kraju testa, dnevni prirast u testu, debljina slanine<br />u slabinskom delu, debljina slanine u leđnom delu, dubina MLD-a, broj legla,<br />priplodna vrednost nazimica procenjena selekcijskim indeksom i procenat mesa<br />u trupu) i dva osnovna reproduktivna parametra (broj živorođene prasadi i broj<br />zalučene prasadi), statistički je analizirana softverskim paketom &bdquo;Statistika<br />13&ldquo; i &bdquo;SPSS verzija 23&ldquo;. Ispitano je postojanje/nepostojanje uticaja svake<br />pojedinačne osobine iz performans testa na reproduktivne osobine<br />Nije utvrđena opšta povezanost svih osobina performans testa i<br />reproduktivnih osobina<br />Analizirane osobine pokazale su veliku zavisnost od genotipa<br />ispitivanih životinja.</p>

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The aim of the study was to investigate the impact of Environmental Education in learners with regard to unacceptable waste dumping which causes land degradation in Mkhondo village. Large parts of the Mkhondo area, including the informal settlement, the location and the local school, are very untidy due to littering by the residents and learners. The situation is contrary to the objectives of the Decade of Education for Sustainable Development (DESD). The study was focused on the impact that Environmental Education as an extracurricular activity would have on the students in reducing or eradicating littering. Data was collected through focus group interviews with the learners and the parents as well as observations. The study revealed that learners showed no concern about the negative impact of disposing of litter inappropriately even after the extra-mural activities on Environmental Education, which indicated that they were not concerned about the environment at school as well as at home. The initiative of Environmental Education was implemented in a short period, hence learners were not yet fully acquainted with the responsibility of taking care of the environment and alleviating littering on the school premises. I therefore recommend that educational campaigns on appropriate solid waste disposal should be initiated in the school and in the community. Further studies should be conducted on how Environmental Education can be integrated in the curriculum as an examinable subject. / Environmental Sciences / M. Ed. (Environmental Education)

Comprendre le fonctionnement des écosystèmes est un enjeu crucial, en particulier dans un contexte de changements globaux. Afin de mieux prédire les processus écosystémiques, j’ai testé la précision et les limites des hypothèses du biomass-ratio de Grime (HBMR) et de l’annulation idiosyncratique (HAI), cette dernière étant une hypothèse originale de cette thèse. Pour cela, j’ai appliqué le principe du biomass-ratio aux traits fonctionnels, en employant la méthode des traits agrégés en communauté, pour estimer la réponse globale des espèces en mélange. La décomposition des litières plurispécifiques constitue un bon modèle biologique, pour lequel je me suis posé les questions suivantes : (1) est-ce que l’HBMR prédit bien les taux de décomposition en mélanges plurispécifiques ? ; (2) est-ce que le degré de variabilité de ces taux diminue pour des raisons biologiques avec l’augmentation de la richesse spécifique (RS) des mélanges (HAI) ? ; (3) est-ce que la variabilité des taux entre mélanges diminue quand les conditions abiotiques du site deviennent plus limitantes ? ; (4)considérant que les mélanges plus contrastés fonctionnellement sont susceptibles de développer plus d’interactions, est-ce que la déviation à la prédiction augmente avec la dispersion fonctionnelle des mélanges(« FDis », La liberté & Legendre 2010) ? Cette thèse inclut deux expériences de décomposition en sachets à litières : (1) à Sherbrooke (QC, Canada) avec des microcosmes, impliquant des litières de six espèces d’arbres, décomposant seules et en mélanges et (2) sur trois sites au climat contrasté dans la région de Clermont-Ferrand (France) avec des litières de quatre espèces d’herbacées, décomposant seules et en mélanges. Les résultats montrent des déviations positives et négatives par rapport aux taux prédits, mais l’HBMR décrit bien la réponse moyenne des litières plurispécifiques. Bien que l’HAI ait été rejetée, les résultats montrent une convergence des taux observés vers les taux prédits quand (1) la RS des mélanges augmente, (2)l’échelle spatiale augmente et (3) le climat est plus limitant pour la décomposition. Enfin, malgré des corrélations entre FDis et interactions entre espèces dans les litières, cette relation n’est pas généralisable et l’hypothèse de corrélation positive entre FDis et déviation à l’HBMR a été rejetée. / Understanding ecosystem functioning is a key goal in ecology, especially in the context of global changes. To better predict ecosystem processes, I tested the accuracy and the limits of Grime’s biomass-ratio (BMRH) hypothesis and a novel idiosyncratic annulment (IAH) hypothesis. I applied the biomass-ratio to functional traits, using the community-weighted means (CWM) to estimate the global response of species in mixtures. I studied the decomposition of litter species mixtures as a biological model and asked the following questions : (1) does the BMRH predict well the decomposition rates of mixed species litters ? ; (2) does the degree of variability of these rates decrease with increasing species richness (SR) beyond that expected from purely mathematical causes (IAH) ? ; (3) does the variability of rates between mixtures decrease with less favourable abiotic conditions for decomposition ? ; (4) as more functionally contrasted mixtures are expected to develop more interactions, does the deviation from prediction increase with increasing functional dispersion in mixtures (« FDis », Laliberté & Legendre 2010) ? This study involves two decomposition experiments using litterbags : (1) at Sherbrooke (QC, Canada), in microcosms, involving litters from six tree species, decomposed alone and in mixtures and (2) in three climatically contrasted sites in the region of Clermont-Ferrand (France) with litters from four herbaceous species, decomposed alone and in mixtures. Despite both positive and negative deviations from expectation occurring at all levels of SR, the BMRH well described the average response of mixed species litters. Although I rejected the IAH, the results showed a convergence to the predicted values based on CWM with (1) increasing the SR in mixtures, (2) increasing the spatial scale of the study and (3) a less favourable climate to decomposition. Finally, although there was a correlation between litter interactions and functional divergence, this relationship was not generalizable and I rejected the hypothesis of a positive correlation between FDis and the deviations from BMRH.

Fimpnedskräpning är ett problem ur flera aspekter. Fimparnas filter har en lång nedbrytnings­tid och innehåller tungmetallen kadmium, den lagras i allt organiskt. Med den största andelen av den totala mängden skräp har samhället varken råd att låta fimparna ligga kvar i naturen eller att plocka upp alla från densamma. Kemiskt och estetiskt såväl som ekonomiskt är fimp­ned­skräpningen ett dåtida, ett nutida och ett framtida problem. Lösningsförslag handlar ofta om restriktioner, ökade investeringar i renhållning eller tillgänglighet. Men en skräpig miljö behöver inte fler skräpinsamlare och botskrivare, utan färre nedskräpare. Filtren på cigaretter består av en plast kallad cellulosaacetat. Pressas de ihop ordentligt är de­formationen plastisk, ett faktum efter utförda experiment. Det konstaterades att bestående tryckmönster i relief kan inpräntas i fimparnas filterplast. Detta ska uppfyllas via mobila ask­koppar, kallade LitterPress. Dessa släcker, kom­primerar och förvarar fimpar samtidigt som de omvandlar dess filter till lottsedlar. Vid användning märks filtren med respektive rökares person- eller telefonnummer i ett pressmoment. Alla ciga­retter är därmed potentiella lotter som kan spåras tillbaka till inlämnarna. Förslaget uppmuntrar rökarna att tömma sina mobila askkoppar i numrerade stationära ask­koppar, kallade LitterBox. Dessa fördelar slump­mässigt fimparna mellan två fack, ett huvudfack där de flesta hamnar och ett mindre fack där betydligt färre hamnar. Varje vecka slumpar ett dataprogram fram ett nummer mellan 1 och antalet uppsatta stationära askkoppar. De som har märkta fimpar, i den utlottade stationära ask­koppens mindre fack, erhåller en kännbar ekonomisk utdelning. Det ska gå att tilldela en eventuell utdelning till en specifik verksamhet. Detta uppfylls genom att den mobila askkoppen ställs in på att märk­a filtren med ett organisationsnummer. Oberoende av märkning kan det parallellt ske en fortlöpande utdelning till välgörande ända­mål, där en bestämd summa skänks för varje fimp i det mindre facket. Detta utgör konceptet Litter­Lott, ett skräplotteri med LitterPress och LitterBox som kompo­nenter. Alla deltagare har en chans att ta del av de skräpkostnader och miljöbelastningar de besparar samhället. Innovativt och pedagogiskt ökar medvetenheten kring både återvinning och kostnader kopplade till nedskräpning. En hemsida annonserar aktuell LitterBox och veckans ”återvinnare”. Där ska det gå att regi­strera medlemskap, följa utvecklingen av LitterLott och delta i ämnes­relaterade diskussioner. Företag, kommunala verksamheter, stiftelser och organisationer kan också anmäla sitt intresse i att vara med och samarbeta för en mer hållbar miljö. Projektets intention är att väcka debatt med fokus på viktiga frågor angående miljö, nedskräp­ning och återvinning. Frågor som är relevanta i dagens samhälle och nödvändiga för morgon­dagens. / Butt littering is a problem in several ways. The filter of the cigarette butts have long degrada­tion time and contain cadmium, a heavy metal stored in organic tissues. With a large fraction of the total amount of litter the society can neither afford to ignore or collect every cigarette butt dropped in the environment. Chemically and esthetically as well as economi­cally butt littering is a past, a present and a future problem. Suggestions of solutions often in­volve re­strictions, increased investments in cleaning efforts or in accessibility. But a littered environ­ment doesn’t need more bins or stricter laws, it needs less littering. Cigarettes have filters that contain a plastic fiber called cellulose acetate. If they are enough compressed the deformation is plastic, a fact after empirical experiments. Definite permanent patterns in relief could be formed within the plastic fiber of the filters. This will be achieved through mobile ashtrays, called LitterPress. These stub out, compress and store cigarette butts along with transforming its filters to lottery tickets. In use, a press motion marks the filters with the social security number or the phone number of each user respectively. In other words, all cigarettes are potential lottery tickets which can be traced to its recycler. The proposition encourages the smokers to empty their mobile ashtrays into numbered sta­tionary ashtrays, called LitterBox. These will randomly di­vide the butts between two com­partments. One is large where the majority end up and one is small, enclosing significantly fewer. A computer program will weekly and randomly pick a number between 1 and the num­ber of stationary installed ashtrays. Those who have their marked cigarette butts in the smaller compartment, of the stationary ashtray of the week, will collect a noticeable economic payoff. There will be possible to allocate any payoff to a specific business. This is done by adjusting the mobile ashtray to mark the filters with an organization number. Irrespective of marking there can also be a continuously payoff to charity, where a fixed amount is allocated for each cigarette butt in the smaller compartment. In action the two physical products are components in the concept of LitterLott, a lottery out of litter. Participants have a chance to receive a part of the litter ex­penses and environmental impositions they spare the society. In an innovative and pedagogic way the awareness in­creases around recycling and what the costs are to refrain. A homepage will announce current LitterBox along with the fortunate recyclers. One may register membership, follow the development of LitterLott and participate in discussions re­lated to the subject. Also companies, municipal businesses and organizations can declare their interests in being a part of the concept and co­operate towards a healthier environment. The intention is to start a debate focusing on important environmentally related questions, litter­ing in general and recycling. Those questions are relevant in today’s society and neces­sary for tomorrows.

Le genre Psychotria est le plus vaste de la famille des Rubiaceae, avec plusieurs centaines d’espèces répandues dans toutes les régions tropicales humides. Les Psychotria sont principalement des arbustes (quelques-uns sont lianescents, herbacés ou arborescents) et entrent souvent pour une part importante dans la composition des sous-bois tropicaux. Certains montrent des adaptations remarquables comme la symbiose bactérienne foliaire ou l’accumulation d’humus. En raison de sa taille et des difficultés d’identifications, ce genre reste mal connu, notamment en Afrique occidentale et centrale où il n’a fait l’objet d’aucun travail d’ensemble depuis les années 1960.<p>Le présent travail a pour objectifs :1) la révision taxonomique du genre Psychotria pour l’Afrique occidentale et centrale; 2) une étude phylogénétique du genre, visant à reconstituer son évolution et améliorer la classification infragénérique ;et 3) une étude biogéographique régionale de ce groupe, afin de définir des centres de diversité et d'endémisme.<p>Notre travail de taxonomie, fondé sur l’examen des spécimens d’herbier et sur des missions de terrain au Cameroun et au Gabon, nous a conduit à reconnaître l’existence de 232 espèces en Afrique occidentale et centrale, ce qui fait de Psychotria le plus vaste genre de plantes dans cette région. Parmi ces espèces, 78 sont nouvelles.<p>Nos travaux phylogénétiques, basés sur l’étude de deux marqueurs nucléaires (ITS et ETS) et quatre chloroplastiques (rps16, trnG, matK et rbcLa), montrent que la classification de Petit (1964, 1966) est largement à revoir. Il apparaît notamment que les deux sous-genres (Psychotria et Tetramerae) reconnus en Afrique, et fondés sur la présence ou l’absence de nodules bactériens foliaires, ne sont pas monophylétiques, certaines espèces ayant secondairement perdu leurs nodules. Nos résultats soutiennent également le rattachement du genre monospécifique Peripeplus à Psychotria.<p>Le genre Psychotria montre une diversité remarquable, associée à un taux d’endémisme élevé, dans le domaine bas-guinéen (Cameroun et Gabon principalement) où plusieurs centres d’endémisme ont été identifiés. Ceux-ci sont localisés non seulement dans les massifs montagneux de l’intérieur, dont la flore particulière est bien connue, mais également dans les régions littorales. L’Afrique de l’ouest, moins diversifiée, montre cependant un fort endémisme localisé principalement dans deux centres, l’un situé au Liberia et dans l’ouest de la Côte d’Ivoire, l’autre vers la frontière Côte d’Ivoire/Ghana. Le bassin du Congo, comparable en diversité à l’Afrique de l’Ouest, est relativement pauvre en endémiques.<p>Ces résultats suggèrent que les forêts du Cameroun et du Gabon auraient relativement bien résisté aux périodes sèches passées, et remettent notamment en question l’hypothèse d’une disparition des forêts littorales du golfe de Guinée au cours du Pleistocène./Psychotria is the largest genus in the Rubiaceae family, with several hundred species in wet tropical areas worldwide. Psychotria spp. are mostly shrubs (a few being lianas, creepers or trees) and are often an important component of the undergrowth in tropical rainforests. Some show remarkable adaptations such as leaf bacterial symbiosis or litter gathering. Due to its size and identification problems, Psychotria remains a little-known genus, especially in West and Central Africa, where no major work has been done on this group since the 1960s.<p>The aims of the present work are: 1) a taxonomic revision of Psychotria in West and Central Africa; 2) a phylogenetic study of the genus, in order to trace its evolution and improve the infrageneric classification; and 3) a regional biogeographic study of the genus, to define centers of diversity and endemism.<p>Our taxonomical work, based on the study of herbarium specimens and field expeditions in Gabon and Cameroon, led us to recognise 232 species of Psychotria in West and Central Africa. Psychotria is therefore the largest plant genus in this area. Among these species, 78 are new.<p>Our phylogenetic work, based on two nuclear markers (ITS and ETS) and four chloroplastic markers (rps16, trnG, matK, rbcLa), shows that Petit’s (1964, 1966) infrageneric classification is in need of revision. In particular, we show that the two subgenera present in Africa (subg. Tetramerae and subg. Psychotria), which are defined by the presence or absence of leaf bacterial nodules, are not monophyletic: a secondary loss of the bacterial nodules has occured in some species. Our results also support the merging of the monospecific genus Peripeplus into Psychotria.<p>The genus Psychotria shows a remarkable diversity and a high level and endemism in the Lower Guinea domain (particularly Cameroon and Gabon) where several centers of endemism are identified. These are located not only in the inland hill ranges, which are well known for their particular flora, but also in littoral areas. West Africa is less diverse but also shows a high level of endemism, which concerns mostly two areas, one in Liberia and western Côte d’Ivoire and the other around the Côte d’Ivoire/Ghana border. The Congo basin, comparable in diversity to West Africa, has relatively few endemic species.<p>These results suggest that the rainforests of Cameroon and Gabon resisted relatively well during historical drier periods. They do not support the hypothesis of a disappearance of the Gulf of Guinea littoral forests during the Pleistocene.<p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished