Thèses sur le sujet « Macroterme »
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1
Kettler, Rolf. « Aktivität im Nestumfeld und territoriale Konkurrenz bei den Termiten "Macrotermes subhyalinus" und "Macrotermes bellicosus" / ». [S.l.] : [s.n.], 1995. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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JOHNSON, AMPAH. « Etude du polymorphisme enzymatique de macrotermes bellicosus (termitid : macrotermitin) ». Paris 12, 1999. http://www.theses.fr/1999PA120027.
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Le termite macrotermes bellicosus (isoptere) est present dans toute l'afrique subsahelienne jusqu'aux confins de l'afrique australe. Cette vaste repartition geographique peut entrainer chez les populations qui evoluent dans des habitats differents des divergences genetiques. Des echantillons sont preleves en cote d'ivoire et au tchad. Dans des conditions de restriction alimentaire les individus du tchad ont un taux de survie plus eleve que ceux de la cote d'ivoire. Des analyses morphometriques sur les soldats revelent une variation intra et inter-population. Cependant, l'etude de quelques enzymes digestives ne montre aucune difference qualitative particuliere entre les populations. Une etude electrophoretique de 22 loci montre que 19 sont monomorphes. Le pourcentage de loci polymorphes n'est que de 13%. Macrotermes bellicosus presente une variabilite electrophoretique moins elevee que beaucoup d'autres insectes. Cette faible diversite genetique chez macrotermes bellicosus, dont les individus sont tous diploides, est semblable a celle d'autres insectes sociaux comme les hymenopteres qui comptent des membres haploides dans leurs colonies. Les loci polymorphes, (l'esterase, l'amylase, la -glucosidase) permettent de constater des taux de polymorphisme differents, 14% et 4,5% respectivement en cote d'ivoire et au tchad. Cependant la distance genetique de 0,058 entre les deux populations est faible. Une derive genetique inherente aux insectes sociaux ou une pression de selection differente sur les deux populations peuvent expliquer ces observations. La -glucosidase dont le profil electrophoretique est specifique a chaque population a ete purifiee. La comparaison des proprietes des -glucosidases d'individus des deux pays revele des differences structurales et biochimiques. Ces differences sont en relation avec les contextes climatiques des pays ou les echantillons ont ete preleves traduisant ainsi une adaptation de chaque population a son environnement.
3
Schilliger, Elmar. « Die Aktivität der Umgebungserschliessung bei der Termite Macrotermes bellicosus (Smeathman) / ». Bern, 1990. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Abebe, Haimanot. « Potential of entomopathogenic fungi for the control of Macrotermes subhyalinus (Isoptera : Termitidae) ». [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=968069312.
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Abou-Houly, Haitham. « Investigation of flow through and around the Macrotermes michaelseni termite mound skin ». Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/8466.
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Macrotermitinae mounds could hold the key for designing a naturally ventilated human habitation using the sustainable Solar and Wind energies. Few attempts were made to mimic these structures into man build structures to achieve natural ventilation. Yet the limited understanding of the ventilation mechanisms applied in these mounds and the lack of fully developed building technologies capable of implementing such complex designs have prevented its further implementation in human habitation. A number of ventilation mechanisms were proposed, however, they are yet to be established. A prerequisite for a thorough understanding of the ventilation mechanism is the comprehension of the role of the mound skin in controlling of ventilation. This thesis focused on studying the flow through the porous mound skin into and out of the mound interior and the flow around the external skin surface. The Macrotermes michaelseni mound structure was visualised and studied in detail by means of field experiments to reveal its plaster-filled internal structure and digital scanning of a plaster-filled mound. The dimensions and interconnectivity of the internal conduits were examined to establish the source of maximum flow resistance. The mound skin and the built-in egress channels were found to be responsible for the bulk of the flow resistance. Computational Fluid dynamics CFD was used to predict the flow rates through the mound skin structure and the internal and external flow patterns. A series of Micro-CFD simulations were conducted to examine the effect of egress channel on the predicted flow rate through the porous mound skin. The effect of the mound conical shape on the external pressure distribution and flow patterns around and within the mound were predicted by Macro-CFD simulation. Wind tunnel experiments were conducted to validate the Macro-CFD analysis. Egress channels are present across the height of the mound stemming from a network of surface conduits that is directly below the mound skin. The surface conduits are highly connected to each other, to the mound central chimney and to the nest structure via peripheral subterranean conduits creating a highly connected network of air conduits. Egress channels keep the mound internal conduits separate from the ambient environment under normal conditions of dry weather. These channels are opened to the skin external surface under rainy conditions to compensate for mound skin diminished air permeability. The flow through the mound skin with closed egress channels is highly sensitive to changes in the egress channel depth from the external skin surface rather than changes in the skin thickness. Closed egress channels within the mound skin doubles the flow rate through the mound. This exceeds the amount necessary for the colony metabolism to allow for part of the inflow to circulate the mound conduits and leave without reaching the subterranean nest structure. Open egress channels increase the flow rate by 1.3 times that of closed egress channels which is necessary during rainy conditions where the mound skin is impermeable. The mound spire is the most efficient in capturing air flow into the mound allowing just under 70% of the total flow rate through the mound skin. Fresh air enters the mound from the upwind conduits with an internal flow velocity ranging from 3 - 12 mm/s. Spent air leaves the mound interior from the lateral and downwind sides. The mound conical shape results in directing the inflow downwards and the outflow upwards.
6
Gerber, Christoph. « Bedeutung der Termite Macrotermes bellicosus (Smeathman) beim Abbau von totem pflanzlichem Material in Kokosplantagen / ». [S.l : s.n.], 1986. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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7
Veivers, Pamela Christine. « Biochemical aspects of symbiosis in carbon and nitrogen metabolism in higher termites ». Thesis, The University of Sydney, 1995. https://hdl.handle.net/2123/26814.
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A comprehensive study of carbon metabolism has been carried out on representatives of two genera of higher termites, Nasutitermes walkeri and the fungus gardeners, Macrotermes spp. Substantial activity of cellulase and its components endo-B-l,4—glucanase and B—glucosidase, was found in workers of N. walkeri, Macrotermes michaelseni M. subhyalinus, M. bellicosus and M. mulleri. Less activity was found in the soldiers and none in the larvae of the Macrotermes spp. In fungal material associated with Macrotermes spp. only the fungal nodules had significant enzyme activity. In N. walkeri and M. michaelseni at least 90% of all enzyme activities was found in the midgut, with the exception of endo-B-l,4-xy1anase activity which was not measured in M. michaelseni. Low levels of endo-fi-l,4—xylanase activity were evenly distributed throughout the gut of N. walkeri. Midgut enzyme activity was restricted to the anterior region. The salivary glands contained variable amounts of enzyme activities. Less than 5% of the endo-B-l,4— glucanase activity was located in the hindgut. The endogenous cellulase from N. walkeri consisted of multiple B-glucosidase and endo-B-1,4- glucanase components. Elution profiles of fungal endo-B—l,4—glucanase activities on Bio-Gel® P-150 indicate that each Macrotermes spp. has a different Termitomyces sp. associated with it, consisting of one to three endo-B-l,4-glucanase activities. Endo-B-1,4-glucanase components from termite workers also consisted of one to three enzymes. A comparison of the elution profiles on Bio-Gel® P-60 of endo-B-lA—glucanase and Bglucosidase activities from fungal and termite material was used to show the absence of fungal enzymes in the termite gut. Similar results were found with fungal and termite material from M. bellicosus and M. mulleri using Bio-Gel® P—150 chromatography.
8
Kalathilparambil, Jayanthan Jayalal. « Identification of core gut bacterial community of royal pair of a fungus-growing termite, Macrotermes natalensis ». Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16727.
Texte intégralRésumé :
Approximately 30 million years ago, ancestors of fungus-growing termites started an obligate mutualistic relationship with a Basidiomycete fungus Termitomyces. The success of this obligate relation is the division of labour and reliance on termite caste gut microbial symbionts. Termites workers maintain Termitomyces fungal garden with their workforce and dual gut passage while the soldier caste protects the colony from predators. The fungal garden concurrently provides enough food for the colony members. Royal pair (a king and a queen) is the centralised caste in the colony, and they control the colony population by their massive reproduction, but their gut community composition remains unexplored. This project aimed to characterise the gut microbes associated with royal pairs of a fungus‐growing termite species Macrotermes natalensis. Four colonies were explored using high throughput sequencing of 16S rRNA gene amplicon dataset. The high-throughput sequence result showed that royal gut microbiotas were comprised of a lower number of bacterial taxa than sterile caste (workers and soldiers). This less number of bacterial taxa suggested that the royal pair gut was completely decoupled from the sterile castes gut, which indicates that the royal pair were possibly provided with a unique diet. The study also showed diversity in bacterial genus-level OTUs of royal pairs in all four colonies which indicated that there is a diet variation between the king and queen. The media predicting strategy could facilitate future cultivation efforts for targeted royal pair gut bacterial strains.
9
Matoub, Mustapha. « La symbiose termite-champignon chez "Macrotermes bellicosus (Termitidae, Macrotermitinae)" : rôle des enzymes acquises dans la xylanolyse ». Paris 12, 1993. http://www.theses.fr/1993PA120048.
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Nous avons essaye de preciser quelles etaient les relations symbiotiques qui existaient entre le termite macrotermes bellicosus et le champignon qu'il cultive dans son nid. Le role de la meule a d'abord ete etudie dans les constructions des ouvriers en elevage. Les cinetiques et les vitesses d'incorporation des sucres reducteurs et des proteines dans les constructions montrent l'importance de la meule dans l'activite constructive des ouvriers. Par ailleurs, l'etude du metabolisme digestif des ouvriers de macrotermes bellicosus et de leur champignon symbiotique a permis de mettre en evidence leur caractere fortement xylanolytique. L'activite cellulolytique a une composante mineure de leur metabolisme. Afin de preciser les modalites de la symbiose digestive chez macrotermes bellicosus, nous avons donc entrepris la purification des complexes xylanolytiques et d'une des composantes du complexe cellulolytique presents dans le tube digestif du termite et dans les mycotetes de son champignon symbiotique. Au total 7 enzymes ont ete purifiees. Chez le termite, le complexe xylanolytique est constitue d'une endoxylanase, d'une exoxylanase et d'une beta-xylosidase. Chez le champignon symbiotique, il est constitue d'une endoxylanase et d'une exoxylanase. Deux endocellulases ont ete egalement purifiees, l'une a partir du tube digestif du termite, l'autre a partir des mycotetes du champignon symbiotique. La comparaison des proprietes biochimiques et structurales de ces enzymes nous permet d'affirmer que l'endoxylanase et l'endocellulase du termite sont d'origine fongique. Sur les trois enzymes purifiees a partir des mycotetes seules deux sont presentes dans le tube digestif des ouvriers. Le role de l'endoxylanase dans la physiologie digestive du termite a ete precise par des experiences de survie d'ouvriers places dans differentes conditions alimentaires completees par des dosages de leur activite xylanasique. Des mycotetes comme seule source d'alimentation n'augmentent pas la duree de survie des ouvriers mais permettent une forte augmentation de l'activite xylanasique. L'endoxylanase est donc capable de s'accumuler dans le tube digestif des ouvriers. Par ailleurs, une etude de l'action en synergie, entre l'endoxylanase et l'exoxylanase du termite, a ete effectuee. Un melange constitue par 20 pour cent d'endoxylanase et 80 pour cent d'exoxylanase conduit a une augmentation de 90 pour cent de l'activite specifique. Ces deux enzymes issues d'organismes differents degradent donc en synergie le xylane. L'endoxylanase, acquise par le termite en consommant des mycotetes, complete son equipement enzymatique et lui permet de degrader avec plus d'efficacite le xylane
10
Duboisset, Arnaud. « L'importance agricole des termitières épigées dans le nord du Cameroun : l'exemple des nids de Macrotermes subhyalinus et d'Odontotermes magdalenae ». Paris 12, 2003. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002150080204611&vid=upec.
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Cette étude vise à décrire les caractéristiques agropédologiques des nids de M. Subhyalinus et d'O. Magdalenae et à déterminer leur importance dans deux agrosystèmes du nord du Cameroun. Elle montre que les propriétés pédologiques des nids font de ces stations un élément indépendant du découpage du parcellaire et de la conduite des itinéraires techniques. Dans les sols ferrugineux de piémont, les nids de Macrotermes génèrent de véritables îlots de fertilité desquels sont dégagées des productions substantielles en céréale. En redistribuant des argiles 2/1 en surface du sol, ils augmentent la CEC et les teneurs en cations échangeables, tout en favorisant la structuration des horizons superficiels. Dans les vertisols, les nids d'Odontotermes détruits se singularisent par une forte macroporosité qui leurs confère un comportement hydrique et mécanique spécifique. L'hétérogénéité ainsi créée est valorisée pour réduire la durée des pépinières de muskuwaari et étaler les chantiers de repiquageThis work aims to describe the agropedologic characteristics of the mounds built by M. Subhyalinus and O. Magdalenae and to specify their role in two farming systems of the north of Cameroon. It shows that the singular pedological properties of the nests put these stations as an area independent of the field pattern and the crop managment. On an arenitic alfisol, the mounds of Macrotermes create true islands of fertility from which substantial productions of cereals are obtained. By redistribuiting 2/1 clays on the soil surface, they increase the CEC and the contents of exchangeable cations, while promoting structuring processes. On a vertisol, the mounds of Odontotermes, after their pulling-down, are made conspicuous by a strong macroporosity which confer theni specific water retention and particular mechanical behavior. Heterogeneity thus created s used to reduce the time required for seedbeds of muskuwaari and to lengthen the operations of the transplanting of sorghum
11
Duboisset, Arnaud Garnier-Zarli Evelyne. « L'importance agricole des termitières épigées dans le nord du Cameroun l'exemple des nids de Macrotermes subhyalinus et d'Odontotermes magdalenae / ». Créteil : Université de Paris-Val-de-Marne, 2003. http://doxa.scd.univ-paris12.fr:80/theses/th0215008.htm.
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Meyer, Victor Wilhelm. « Intracolonial demography, biomass and food consumption of Macrotermes natalensis (Haviland) (Isoptera : Termitidae) colonies in the northern Kruger National Park, South Africa ». Diss., Pretoria : [s.n.], 2001. http://upetd.up.ac.za.thesis/available.etd-10092002-124728.
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Rouland, Corinne. « Contribution à l'étude des osidases digestives de plusieurs espèces de termites africains purification et caractérisation des cellulases et des xylanase du termite Macrotermes mülleri... / ». Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37600887g.
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Rouland-Lefèvre, Corinne. « Contribution à l'étude des osidases digestives de plusieurs espèces de termites africains : purification et caractérisation des cellulases et des xylanases du termite Macrotermes mülleri (Termitidae, Macroterminae) et de son champignon symbiotique ». Paris 12, 1986. http://www.theses.fr/1986PA120022.
Texte intégralRésumé :
L'etude des osidases digestives presentes dans l'intestin moyen et l'intestin posterieur de 6 especes de termites a ete entreprise afin de preciser le mode de nutrition de ces termites et leur impact sur les differents substrats vegetaux et de comparer les roles respectifs du termite et des micro-organismes symbiotiques dans la degradation de la matiere vegetale
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Hager, Felix A. [Verfasser], Wolfgang H. [Gutachter] Kirchner et Dominik [Gutachter] Begerow. « Vibrationskommunikation bei Termiten : Kontext, Information und Physik der Alarmsignale von Macrotermes natalensis (Isoptera, Macrotermitidae) sowie ein Vergleich mit anderen Termitenarten / Felix Alexander Hager ; Gutachter : Wolfgang H. Kirchner, Dominik Begerow ; Fakultät für Biologie und Biotechnologie ». Bochum : Ruhr-Universität Bochum, 2013. http://d-nb.info/1214440665/34.
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Hager, Felix Alexander [Verfasser], Wolfgang H. [Gutachter] Kirchner et Dominik [Gutachter] Begerow. « Vibrationskommunikation bei Termiten : Kontext, Information und Physik der Alarmsignale von Macrotermes natalensis (Isoptera, Macrotermitidae) sowie ein Vergleich mit anderen Termitenarten / Felix Alexander Hager ; Gutachter : Wolfgang H. Kirchner, Dominik Begerow ; Fakultät für Biologie und Biotechnologie ». Bochum : Ruhr-Universität Bochum, 2013. http://d-nb.info/1214440665/34.
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Bréan, Simon. « La science-fiction en France de la Seconde Guerre mondiale à la fin des années soixante-dix ». Thesis, Paris 4, 2010. http://www.theses.fr/2010PA040125.
Texte intégralRésumé :
Après la Seconde Guerre mondiale, la littérature de science-fiction s’est développée en France sous la forme d’un sous-champ isolé au sein du champ littéraire, avec ses collections, ses critiques et ses lecteurs spécifiques. Cette littérature produit des univers fictionnels en tension entre la réalité conventionnelle et des états alternatifs de cette réalité, selon une modalité dénommée dans la thèse le « régime ontologique matérialiste spéculatif ». Le corpus des romans a été analysé d’abord dans une perspective diachronique, en présentant une histoire des acteurs, des structures éditoriales et des thèmes de la science-fiction en France, articulée à une réflexion sur les conditions et les perspectives d’écriture des auteurs français. Les romans ont ensuite été analysés de manière à permettre une théorisation à plusieurs niveaux de l’écriture de la science-fiction : le mot et le texte de science-fiction, les mondes fictionnels extrapolés à partir du monde réel et enfin la mémoire collective mise en place par l’ensemble des œuvres, que nous nommons le « macrotexte » de la science-fiction. Notre contribution principale à l’histoire littéraire est l’étude de la manière dont évoluent les représentations communes en science-fiction, sous la forme de paradigmes dominants successifs où les écrivains réinterprètent les images et idées de la science-fiction. Nous avons établi selon quelles modalités le corpus des romans de science-fiction fournit à l’analyse du discours narratif, à la théorie de la fiction et à l’étude de l’intertextualité, des exemples remarquables en raison des dispositifs destinés à mettre les univers de science-fiction en concurrence avec la réalitéAfter the Second World War in France, science fiction literature took the form of an isolated subaltern field within the literary field, featuring specific publishing series, critics and readership. In science fiction novels, fictional worlds are created by mixing conventional reality and alternate states of reality, a process I call “régime ontologique matérialiste spéculatif” (“speculative materialistic ontological status”). I have studied French science fiction novels first from a historical perspective, by describing the protagonists, the publishers and the themes of French science fiction, as well as by assessing how and to what end French science fiction writers wrote their novels. I have then studied these novels at several levels: how words and texts are shaped in science fiction, how fictional worlds are extrapolated from the real world and how science fiction texts generate a collective memory, which I call the “macrotext” of science fiction. Our thesis contributes to literary history by studying how the perception of science fiction gradually changes over time, each main paradigm morphing into a new one as writers adapt science fiction images and ideas to their needs. I have also pointed out how science fiction novels may prove of a keen interest to narrative discourse analysis, fiction theory and intertextuality approach, because of various devices meant to allow science fiction worlds to compete with reality
18
RINALDI, Emanuele. « Valutazione di specie macroterme da tappeto erboso su suoli a diversa tessitura ». Doctoral thesis, 2011. http://hdl.handle.net/10447/102389.
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SEPPOLONI, IRENE. « Valutazione di tappeti erbosi a base di graminacee macroterme a scopi ricreativo-ornamentali ». Doctoral thesis, 2014. http://hdl.handle.net/2158/855107.
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Kitto, Stephen Michael. « Studies of the nests of the fungus-growing termite Macrotermes natalensis (Isoptera : Macrotermitinae) ». Thesis, 1997. http://hdl.handle.net/10413/10295.
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Monthly sampling of 71 laboratory nests, each with a pair of adults, revealed that eggs and first-instar larvae were observed in the third month, minor workers in the fourth month and minor soldiers in the seventh month. Mortality of the pairs was high, with only five pairs surviving over the 10 month period. Laboratory nests did not develop further than the copularium. Excavation of 30 nests, of differing sizes, revealed that five were juvenile nests, consisting of only thin shelving with a few flattened fungus combs scattered throughout, and all, even the
youngest nest (3 to 5 years), had a small mound. The queens from these young nests were small and had white pleural and intersegmental membranes. Twenty mature nests had a medium to large mound with large air passages and a medium to large hive with a well defined fungus garden
containing large fungus combs. The queens from these nests were medium- to large sized, with white to brown pleural and intersegmental membranes. The remaining five nests had mounds often covered with grass, and a hive that contained less fungus comb than expected. The mounds of these nests were classified using their sandy pediment or crumbly texture. These were senescent or declining nests. The queens had pale brown pleural membranes and brown intersegmental membranes, and were often flaccid. The royal cell was commonly found in the middle to upper part of the nursery (20 nests), but sometimes was found at the edge of the nursery (five nests). The royal cells of five nests were not found or had been destroyed during excavation. The "youngest" mound
was one to two years old and the "oldest" was more than 25 years old. The youngest queen was estimated to be three to five years old and the oldest queen more than 27 years. The nest seems to remain subterranean for two or less years before producing a mound. Thirteen nests were vigorous and five declining. The remaining 12 nests could not be classified as no fungus comb was collected from the nests.Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.
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[Verfasser], Haimanot Abebe. « Potential of entomopathogenic fungi for the control of Macrotermes subhyalinus (Isoptera : Termitidae) / von Haimanot Abebe ». 2002. http://d-nb.info/968069312/34.
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Muvengwi, Justice. « Relationships between termite (Macrotermes) mound distribution, plant diversity and large mammalian herbivory patterns in Gonarezhou National Park, Zimbabwe ». Thesis, 2017. http://hdl.handle.net/10539/22729.
Texte intégralRésumé :
A thesis submitted to the Faculty of Science, University
of the Witwatersrand, in fulfilment of the academic
requirements for the degree of Doctor of Philosophy.
August 2016, JohannesburgTermites are widely distributed in tropical and subtropical savanna. They are recognised as major ecosystem engineers through their role in nutrient cycling, decomposition, hydrology and alteration of landscape topography with cascading effects manifesting in ecosystem heterogeneity and productivity up the food chains. In this thesis I addressed the effect of geology on termite species diversity, followed by questioning how the different geologies influence the size and spatial distribution of Macrotermes mounds. Furthermore, I explored the effect of termite mounds emanating from different geologies on herbaceous vegetation heterogeneity and finally the effect this heterogeneity has on grazing intensity. Although the diversity of termites has been explored across different environmental gradients such as rainfall, altitude and disturbance, little is known regarding variation in their diversity across landscapes of varying geology. In my quest to understand how varying geology influences the ecology of termites and their functional importance, I sampled granite and basalt for termite diversity using standard transects (100 m x 2 m). I predicted that termite diversity is higher on nutrient-rich geology following the productivity diversity hypothesis. However, both functional and taxonomic diversity were higher on nutrient-poor granite. Twelve species from three subfamilies representing two feeding groups were recorded on granite whereas on basalt only five species from two subfamilies consisting of one feeding group were recorded. Although the influence of Macrotermes mounds on ecosystem heterogeneity has been well studied, little is known on how the environment (geology) and other termite colonies influence size and distribution pattern, despite how these interactions could influence ecosystem functioning. Termite mounds were sampled in 1 km2 plots, four in each geology. Each mound location was recorded using a hand held GPS and structural variables (height and diameter) measured. The data were analysed for spatial distribution of termite mounds using the software Programita. The general distribution pattern of termite mounds (active and inactive mounds combined) was investigated using both the pair correlation function, g(r), and Ripley’s K(r) function. Termite mounds were larger and covered a significant proportion of the landscape on granite compared to basalt. Mounds were generally over-dispersed on granite and randomly distributed on basalt. Mounds covered ~ 6% of the landscape on granite compared with only ~ 0.4% on basalt. These results show that the significance of termites varies across geologies, being more important on nutrient-poor geologies because of their size and a more productive spatial pattern displayed here. The majority of studies testing mound effects on savanna vegetation spatial heterogeneity have been based on single site observations mostly comparing mounds and their paired savanna control plots. Furthermore studies did not consider the spatial effects of mounds with distance into the savanna matrix from mound edge, and this has rarely been tested across landscapes of varying geologies, as well as across mounds of different sizes. Therefore there was a need to explore this in order to broadly understand the functional importance of mounds. I sampled the herbaceous community on and off termite mounds and along distance transects from mounds on nutrient-rich and nutrient-poor geologies. Termite mounds as sources of spatial vegetation heterogeneity was more pronounced on nutrient-poor granite, with larger mounds having greater effect on vegetation composition and diversity than smaller ones. Mounds harboured compositionally different herbaceous plants compared with the savanna matrix on granite whereas there was no difference on basalt. In acknowledging the effect erosion from mounds may have on vegetation heterogeneity, termite mound effect on composition expressed at landscape level based on mound densities recorded in this study was estimated to be 19% of the landscape on granite whereas on basalt, the mounds influenced ~ 0.4% of the landscape. The choice of foraging sites by large herbivores in the landscape is influenced by food quantity, quality, inter and intra-specific competition and predation risk. Termite mounds harbour highly nutritious herbaceous plants compared to the savanna matrix, which makes them preferred foraging sites. Due to very small differences in soil nutrient content between mounds and savanna on basalt, mounds were expected to have little effect on grazing. In line with the set hypothesis termite mounds largely influenced grazing on the nutrient-poor granite and when viewed at landscape scale, based on mound densities and extent of erosion recorded, mounds influenced ~ 28% on granite and only ~ 0.8% on basalt. Overall my study has demonstrated that the significance of termites as ecosystem engineers varies across landscapes of varying geology, being more important on nutrient-poor compared with nutrient-rich geologies.
MT2017