Mozambique is to fifty percent covered by forest, most of which belongs to the biodiverse miombo woodlands. The last decades, Mozambique has been suffering from rapid deforestation. The once continuous forest cover has turned into a mosaic of forest patches, farmland, settlements etc. The remaining forest patches are in many cases very isolated. These forests have distinct edges towards the neighbouring land, which means that the edge zones have different environmental conditions (more light, higher temperatures etc.) and tree species composition than the interior. In order to examine how the forests of Mozambique are affected by edge effects, the highly isolated Nhamacoa forest was studied. An additional aim of the project was to make a floristic inventory of the forest in order to further assess its conservation status. Specimens were collected, pressed and photographed for identification. Edge effects were studied in plots at the edge and in the interior of the forest in a paired design. Trees inside the plots were identified, counted and measured (dbh (diameter at breast height) and height) to search for differences in species richness, diversity, biomass and height-to-dbh ratios. Environmental parameters (air temp., soil temp., light and slope) were also measured. In total, 76 species of trees were sampled and 44 (35 in the interior and 32 at the edge) of these were found inside the plots. The interior plots harboured significantly more individuals and species of trees than their paired edge plots. Additionally, biomass and height-to-dbh ratios were higher in the interior plots than in the edge plots. These differences strongly suggest that the Nhamacoa forest is affected by edge effects, although none of the measured environmental parameters could explain why. That the Nhamacoa forest is affected by edge effects goes in line with the research hypothesis and shows that it is important to maintain large and intact pieces of forest in order to preserve the Mozambican miombo forests. For future studies, additional environmental parameters (wind speed, humidity etc.) could be examined in order to better explain the presence of edge effects in the Nhamacoa forest.

Africa's miombo woodlands constitute one of the most important dry tropical forests on earth, yet the hydraulic function of these woodlands remains poorly researched. Given the current predictions of increased aridity by the end of this century in the miombo ecoregion, understanding the likely response of miombo woodlands tree species to water stress is crucial in planning adaptation strategies. Predicting the response of miombo woodlands to future climate trends is hampered by a lack of knowledge on the physiology of the common miombo woodlands tree species. In particular, plant-water relations for this woodlands type are not well understood. An understanding of plant-water relations for this woodlands type will provide insights into how water limits tree species distribution in this ecosystem. This will also improve our prediction model on the likely response of this ecosystem to predicted climate change. For this reason, the overall objective of this research was to evaluate the hydraulic architecture and xylem vulnerability to cavitation for nine principal miombo woodlands tree species differing in drought tolerance ability and habitat preference. This was achieved by; examining the hydraulic properties and evaluating the extent to which each hydraulic design was vulnerable to water stress-induced xylem cavitation; investigating how seasonal changes in plant-water relations influences seasonal patterns of leaf display and; analyzing the relationship between stem hydraulic supply and leaf functional traits related to drought tolerance ability. This research has found that drought-intolerant tree species with mesic specialization have more efficient stem hydraulic systems than co-occurring habitat broad ranging species. Broad ranging tree species attain wider habitat distribution by adjusting their hydraulic supply in response to changing ecosystem water availability. The finding that hydraulic properties differ significantly between tree species with contrasting habitat preference suggests that tree hydraulic design may have some adaptive ecological role in influencing species habitat preferences in miombo woodlands. The evaluation of xylem vulnerability to cavitation revealed that mesic specialized tree species were more vulnerable to water stress-induced cavitation than habitat broad ranging tree species. Vulnerability to cavitation in individuals from the same broad-ranging species growing in contrasting habitats showed only marginal and statistically insignificant (P > 0.05) differences between wet and dry sites. In the investigation of the influence of seasonal changes in stem water relations on seasonal leaf display, seasonal rhythms in stem water status were found to exert significant controls on leaf phenology. Mesic specialists had strong stem water controls throughout the year in comparison to broad ranging tree species. An analysis of the relationship between stem hydraulic supply and leaf functional traits suggests that stem hydraulic supply constrains leaf biomass allocation patterns among miombo tree species. Mesic specialists tend to invest more in leaf longevity than broad ranging tree species. This thesis has uncovered some interesting relationships between plant-water-relations and the distribution of miombo woodlands tree species. These results lead to the conclusion that in an event of increased ecosystem drying under future climate trends, tree species with mesic specialisation are at a greater risk of experiencing cavitation related species mortality than broad ranging ones.

African elephants are ‘keystone’ species with respect to biodiversity conservation in Africa since they maintain habitats that support several animal communities by changing vegetation structure through foraging and by dispersing seeds between landscapes. Elephants are also ‘flagship’ species because, given their impressive size, they can make people sympathetic and stimulate local and international concerns for their protection. Economically, elephants contribute to national revenues as tourists are willing to pay to watch them. Despite all these factors, little is known however about elephant movement and how they utilize resources, especially in miombo-wetland ecosystems. This thesis investigates how elephants utilize resources in a miombo-wetland ecosystem in the Ugalla landscape of Western Tanzania over different protected areas containing different resource users. Using Global Positioning System (GPS) collars fitted to six elephants, it was observed that some elephant families are not confined in one protected area in the Ugalla landscape. Rather, they moved readily between different protected areas. Elephant movements were restricted to areas near the rivers, especially the Ugalla River, during the dry season and were dispersed widely during the wet season. As they move, elephants in the miombo woodlands of Ugalla selected the most abundant woody plants for browsing. Common to many woody plants, the browsed plants were short of mineral nutrients (e.g., sodium, calcium). Elephants obtained additional minerals by eating soils from certain termite mounds. Soils from termite mounds are richer in mineral elements (e.g., sodium, calcium, iron) compared to soils from the surrounding flood plain or compared to the browsed plants. However, the recorded termite mounds from which elephants eat soils were not evenly distributed in the landscape but confined mainly to the flood plains in the Ugalla Game Reserve. The Ugalla River, which is the main source of water for the elephants and other animals and also supports fishing activities by the local people in Ugalla during the dry seasons, is infested by the water hyacinth (Eichhornia crassipes). Such infestation potentially limits access to these precious surface water supplies. In addition at the regional level, the Ugalla River is among the major rivers that flow into the Lake Tanganyika which is shared by the countries of Tanzania, Burundi, Democratic Republic of Congo and Zambia. Thus, the spread of water hyacinth if left unchecked threatens to impact Lake Tanganyika, affecting many countries and ecosystem services. This thesis highlights that sustainable conservation of biodiversity in different protected areas in the Ugalla landscape requires an integrated management approach that will embrace conservation of different interrelated landscape resources required by both wildlife and the rural poor populations for their livelihoods. Regular coordinated wildlife anti-poaching patrols should be initiated across the entire Ugalla landscape because the elephants, among other wildlife, utilize different protected areas in Ugalla. Local communities should also be engaged in conservation initiatives (e.g., controlling the spread of the water hyacinth) as these directly impact local livelihoods. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p> / INTEGRATED NATURAL RESOURCES MANAGEMENT

<p>This thesis aims to show how biogeophysical and social processes are interlinked in landscape change, and to propose approaches for interdisciplinary environmental assessments (such as EIAs), concentrating on developing countries’ situations, and representation of findings from such studies. </p><p>Landscape in its holistic sense is a very good concept and basis for intellectual and practical use in environmental dialogues. However, landscapes are valued and assessed differently, depending on cultural background along with individual characteristics. </p><p>Methods of conducting interdisciplinary environmental assessments need to vary, but it is important to follow a structure to avoid too broad and general studies that only assemble a few factors and present them without an integrated synthesis. This thesis has suggested one research sequence and structure that has proven to be practical and possible to execute in areas where data is scarce and where local involvement is a major component. It extends the observation period in time and space where remote sensing analyses are integrated with interviews, archive material, land-cover assessments and soil analyses.</p><p>Case studies from Tanzania have been used to investigate how perceptions of land and resources manifest themselves at local scales and how this information can contribute to sustainable environmental planning. Preferences and perceptions of land as being ‘important’ and ‘good’ do not always correlate with favourable biogeophysical conditions, indicating that both social services, such as health care, access to markets, education and employment, as well as “non-rational” factors are essential to consider in environmental planning and management.</p><p>This study has partly been part of a larger research project investigating the links between human livelihood and biodiversity in <i>miombo</i> woodlands. It has been shown how <i>miombo</i> woodland is important to local populations as it provides material goods as well as many intangible services. However, it is also associated with problems and dangers, which are important to consider and understand in planning for the environment and sustainable development.</p>

This thesis aims to show how biogeophysical and social processes are interlinked in landscape change, and to propose approaches for interdisciplinary environmental assessments (such as EIAs), concentrating on developing countries’ situations, and representation of findings from such studies. Landscape in its holistic sense is a very good concept and basis for intellectual and practical use in environmental dialogues. However, landscapes are valued and assessed differently, depending on cultural background along with individual characteristics. Methods of conducting interdisciplinary environmental assessments need to vary, but it is important to follow a structure to avoid too broad and general studies that only assemble a few factors and present them without an integrated synthesis. This thesis has suggested one research sequence and structure that has proven to be practical and possible to execute in areas where data is scarce and where local involvement is a major component. It extends the observation period in time and space where remote sensing analyses are integrated with interviews, archive material, land-cover assessments and soil analyses. Case studies from Tanzania have been used to investigate how perceptions of land and resources manifest themselves at local scales and how this information can contribute to sustainable environmental planning. Preferences and perceptions of land as being ‘important’ and ‘good’ do not always correlate with favourable biogeophysical conditions, indicating that both social services, such as health care, access to markets, education and employment, as well as “non-rational” factors are essential to consider in environmental planning and management. This study has partly been part of a larger research project investigating the links between human livelihood and biodiversity in miombo woodlands. It has been shown how miombo woodland is important to local populations as it provides material goods as well as many intangible services. However, it is also associated with problems and dangers, which are important to consider and understand in planning for the environment and sustainable development.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Current efforts to address Zimbabwe‘s decade long veld fire crisis has partly been hindered by a lack of financial resources and fire data. This study illustrates the potential of using the MODIS burned area product as an alternative cost- and time-effective method for reconstructing historical fire records in Zimbabwe. Two MODIS burned area products were evaluated, namely the MCD45A1 and WAMIS (Meraka Institute‘s MODIS burned area product). Both products yielded similar levels of accuracy despite the difference in algorithms. However, it is assumed that at certain thresholds, either in tree cover or fire intensity, WAMIS ceases to map fires as accurately as the MCD45A1. Ten years of fire data for Charara Safari Area (CSA) was extracted from the MCD45A1, and used as a basis to establish six parameters: fire incidence, extent, seasonality, fire size, frequency and fire return interval (FRI). It was observed that approximately 50% of CSA burned annually, with an average of 132 fires occurring every year. Although there was no overall increase or decrease in the extent of area burned over the 10 year study period, an increasing trend in fire incidence was noted. Through an assessment of effective fire size, it was established that more fires in CSA were gradually becoming smaller in size, while the extent of area burned remained fairly constant. Hence, the increase in fire incidences and lack of a corresponding increase in area burned. This study was also used to identify areas in the fire regime that may be a potential ecological risk to the miombo woodland in CSA. Three points of concern were revealed: firstly, a high prevalence of late season fires was observed in the northern bounds of CSA. Secondly, 64.2% of the total area burned in CSA burned between 6 and 10 times over the 10 year period, and lastly, 85% of the total area burned over the period 2001 and 2010 had a FRI of less than 2 years. The combination of late season fires, high fire frequency and short FRI in CSA is indicative of possible alterations in the state of the miombo woodlands, which may have negative socio-economic implications on CSA and its surrounding communities. This study has demonstrated that the MCD45A1 is a useful source of much needed fire information for Zimbabwe. Therefore, the possibility of integrating methods employed in this study into the current collection of fire data should be given due consideration. / AFRIKAANSE OPSOMMING: Huidige pogings om Zimbabwe se dekade lank veldbrand krisis aan te spreek is gedeeltelik belemmer deur 'n gebrek aan finansiële hulpbronne en vuurdata. Hierdie studie illustreer die potensiaal van die gebruik van die MODIS verbrande area produk as 'n alternatiewe koste-en tyd-effektiewe metode vir die rekonstruksie van historiese vuurrekords in Zimbabwe. Twee MODIS verbrande area produkte is geëvalueer, naamlik die MCD45A1 en WAMIS (Meraka Instituut se MODIS verbrand area produk). Beide produkte het soortgelyke vlakke van akkuraatheid opgelewer ten spyte van die verskil in die algoritmes. Dit word egter aanvaar dat op sekere drempels, óf in die boom bedekking, of brandintensiteit, WAMIS brande minder akkuraat karteer as die MCD45A1 produk. Tien jaar van vuurdata vir Charara Safari Area (CSA) is uit die MCD45A1 data onttrek, en gebruik as 'n basis om ses parameters vas te stel: vuurvoorkoms, omvang, seisoenaliteit, vuurgrootte, frekwensie en tyd tussen die terugkeer van vuur na ‗n spesifieke plek (nl. FRI). Dit is waargeneem dat ongeveer 50% van die CSA jaarliks gebrand word, met 'n gemiddeld van 132 brande wat elke jaar voorkom. Daar was nie 'n algehele toename of afname in die omvang van die totale verbrande area oor die 10 jaar studietydperk nie. Maar 'n toenemende neiging in die vuurvoorkoms was wel opgemerk. Deur middel van 'n assessering van effektiewe vuurgrootte, is daar vasgestel dat meer kleiner brande in CSA voorkom, terwyl die omvang van die verbrand area redelik konstant gebly het. Dus was daar ‗n toename in die aantal vuurvoorvalle al was daar nie 'n ooreenstemmende toename in die totale verbrande oppervlakte was nie. Hierdie studie is ook gebruik om gebiede in die vuurregime te identifiseer wat 'n potensiële ekologiese risiko vir die miombobosveld in CSA inhou. Drie punte van kommer word geopenbaar: eerstens, 'n hoë voorkoms van laatseisoen brande is waargeneem in die noordelike grense van CSA. Tweedens, 64,2% van die totale verbrande oppervlakte in die CSA brand tussen 6 en 10 keer bine die 10-jaar periode. Laastens, 85% van die totale verbrande oppervlakte oor die tydperk 2001 tot 2010 het 'n FRI van minder as twee jaar. Die kombinasie van laatseisoen brande, hoë vuurfrekwensie en kort FRI in CSA is 'n aanduiding van moontlike veranderinge in die toestand van die miomboveld, wat negatiewe sosio-ekonomiese implikasies op die CSA en die omliggende gemeenskappe kan uitoefen. Hierdie studie het getoon dat die MCD45A1 'n nuttige bron van broodnodige vuur inligting vir Zimbabwe is. Daarom, moet die moontlikheid van die integrasie van die metodes wat gebruik word in hierdie studie in die huidige versameling van vuurdata behoorlike oorweging gegee word.

Dans la province du Haut-Katanga, en République démocratique du Congo (RD Congo), une forte pression anthropique est exercée sur la forêt claire (FC, Miombo) par l’agriculture et la demande accrue en charbon de bois, due à la croissance démographique. La restauration de la FC dégradée est devenue essentielle pour renverser cette régression et gérer durablement la FC. L’objectif principal de cette thèse était d’étudier la croissance de semis et le potentieldes champignons mycorhiziens arbusculaires (CMA). Elle avait pour objectifs spécifiques:(i) d’évaluer la croissance et le statut mycorhizien des espèces forestières de la FC, en lien avec le statut de succession, espèces pionnières (EP) et tardives (ET); (ii) de déterminer le potentiel d’inoculum mycorhizien arbusculaire (PIMA) dans la FC dégradée; et (iii) de décrire la communauté des CMA, associés à un arbre forestier à usage multiple (Pterocarpustinctorius Welw ou Mninga maji en Swahili, Mukula en Bemba).D’abord, la croissance des semis a été évaluée, pour deux espèces d’arbres pionnières(Combretum collinum et Pterocarpus tinctorius) et six espèces tardives (Brachystegiaboehmii, B. longifolia, B. spiciformis, B. wangermeana, Julbernardia globiflora et J.paniculata), 1, 2 et 4 ans après la plantation. Ensuite, le PIMA a été évalué par le piégeage des plantules de Crotalaria juncea dans la FC dégradée. La relation entre le PIMA et les indices de végétation a été établie avec les modèles linéaires généralisées mixtes (MLGM)et les régressions linéaires. En dernier lieu, la diversité et la structure de la communauté des CMA des racines de P. tinctorius ont été caractérisées dans les jachères agricoles et forestières de trois sites, par amplification, clonage du gène 28S de la grande sous-unité(LSU) de l’ADN ribosomal et le séquençage Sanger. Les résultats montrent que les espèces forestières pionnières (EP, Chipya) avaient une croissance précoce et une productivité 3 à 40 fois supérieure comparées aux ET (typique du Miombo). Les espèces pionnières étaient colonisées par les CMA, alors que les espèces tardives l’étaient par les ectomycorhizes. Par ailleurs, la densité des arbres des EP influence positivement le PIMA, particulièrement les légumineuses ligneuses agissant en synergie avec l’abondance des herbacées annuelles. Par leur colonisation mycorhizienne élevée, les légumineuses ligneuses seraient les plantes refuges des CMA. Finalement, une diversité moléculaire de 30 unités taxonomiques opérationnelles (UTOs) des CMA était associée à P.tinctorius (une des légumineuses ligneuses mycotrophes), dans les friches agricoles et forestières de trois sites étudiés. La richesse spécifique et la structure de la communauté des CMA étaient influencées par la densité des espèces ligneuses, colonisées par les CMA, équitablement réparties dans les espèces végétales. De plus, la communauté des CMA était dominée par les espèces du genre Rhizophagus et Sclerocystis, qui étaient fortement associées à certaines propriétés chimiques du sol (pH, acidité, Al et Fe total) et à la densité de quelques arbres. Ainsi, les résultats mettent en évidence une variabilité de la croissance et de la biomasse en fonction du statut de succession (groupes écologiques). Aussi, le PIMA et la communauté des CMA étaient contrôlés par la densité des arbres et quelques propriétés du sol. Nous suggérons la reforestation de la forêt claire dégradée avec les espèces indigènes (P.tinctorius, B. spiciformis et C. collinum), en plantations mono spécifiques ou en régie agroforestière avec les cultures vivrières. / In the Katanga province, Democratic Republic of the Congo (DR Congo), the anthropogenic pressure is exerted on the Miombo woodland (MW) with the expansion of the agricultural lands and the increased demand for charcoal, due to the demographic growth. The restorationof agricultural and forest fallows has become essential to reverse this decline and sustainably manage the degraded MW. The main objective of this thesis was to study the development of seedlings and the potential of arbuscular mycorrhizal fungi (AMF) in the MW of UpperKatanga, DRC. Its specific objectives were to: (i) assess the development and mycorrhizalstatus of MW species, with respect to their successional status (early (ES) or late (LS) tree species); (ii) determine the arbuscular mycorrhizal inoculum potential (AMIP) in degradedMW; and (iii) describe the diversity and community structure of AMF associated with amultipurpose forest tree (Pterocarpus tinctorius Welw also named Mninga maji in Swahili,Mukula in Bemba).First, the development of the seedlings was evaluated, for two pioneer tree species(Combretum collinum and P. tinctorius) and six late species (Brachystegia boehmii, B.longifolia, B. spiciformis, B. wangermeana, Julbernardia globiflora and J. paniculata), 1, 2and 4 years after planting. Then, the AMIP was estimated in degraded MW by baitingCrotalaria juncea seedlings. The relationship between AMIP and vegetation indix wase stablished with Generalized Linear Mixed Models (GLMM) and linear regressions. Finally, the diversity and the structure of the AMF community in the roots of P. tinctorius were characterized in the agricultural and forest fallow of three sites, by amplification, cloning of the 28S gene of the large subunit (LSU) of the ribosomal DNA and Sanger sequencing. The results showed that the early successional tree species, ES (Chipya) had early growthand were 3 to 40 times more productive than to LS (tree species characteristic of MW). ESspecies were colonized by AMF, whereas LS species were colonized by ectomycorrhizal fungi. In degraded MW, the density of some trees had a positive influence on AMIP,particularly woody legumes acting synergistically with the abundance of annual grasses.Woody legumes were more colonized and would act as AMF plant refuges. Molecular diversity of 30 operational taxonomic units (UTOs) of AMF was associated with P. tinctorius (one of the mycotrophic woody legumes), in the agricultural and forest fallows of three sites studied. The community richness and structure of the AMF were driven by the density ofwoody species colonized by AMF evenly distributed in plant species. The AMF communitywas dominated by species of the genera Rhizophagus and Sclerocystis, and were strongly associated with some chemical properties of the soil (pH, acidity, total aluminium and totaliron) and the density of some trees. Thus, the results highlight a variability of growth and biomass depending on the successional status (ecological groups). Also, the AMIP and the AMF communities were mainly driven by tree density and soil properties. We suggest there forestation of degraded MW with the native species (P. tinctorius, B. spiciformis and C.collinum) in mono-specific plantations or under agroforestry management with food crops.

La compréhension des processus écologiques qui sous-tendent l’assemblage des communautés végétales et la coexistence des espèces est un objectif central en écologie. Ces processus sont potentiellement nombreux et de natures contrastées. Ainsi, la composition d’une communauté de plantes dépend de processus déterministes liés aux conditions environnementales abiotiques (climat, conditions physiques et chimiques du sol, lumière) et d’interactions biotiques complexes, positives (facilitation, symbioses) comme négatives (compétition, prédation, pathogènes). En outre, les communautés sont influencées par des processus stochastiques (capacité de dispersion limitée, dérive écologique). Si les mécanismes à l’origine de ces processus sont très différents, ils ont néanmoins en commun la génération de motifs (patterns) spatiaux de distribution d’espèces dans les communautés. L’analyse de la structure spatiale des communautés permet ainsi une étude indirecte des processus régissant les communautés. La nature complexe de ces patterns spatiaux a mené au développement de nombreuses méthodes statistiques de détection et de description de patterns. Les méthodes basées sur des vecteurs propres spatiaux sont parmi les plus puissantes et précises pour détecter des patterns complexes et multi-échelles. Ces vecteurs propres, utilisés comme prédicteurs spatiaux, peuvent être combinés à un ensemble de variables environnementales dans un cadre de partition de variation. Celui-ci permet, en théorie, de démêler les effets uniques et l’effet conjoint des variables environnementales et spatiales sur la variation de composition d’une communauté. Il mène ainsi à une quantification de l’action des processus déterministes et des processus stochastiques sur l’assemblage de la communauté. Néanmoins, je montre dans cette thèse qu’un certain flou méthodologique concernant deux étapes déterminantes des analyses basées sur les vecteurs propres spatiaux a mené une proportion élevée d’études à utiliser ces méthodes de manière sous-optimale, voire fortement biaisée. Ceci compromet la fiabilité des patterns spatiaux détectés et des processus écologiques inférés. Une autre limitation de ce cadre d’analyse concerne la fraction de la partition de variation décrivant l’effet environnemental spatialement structurés qu’aucune méthode ne permet de tester.Cette thèse présente des solutions non biaisées, puissantes et précises à ces différentes limitations méthodologiques et permet d’élargir le cadre de l’inférence de processus écologique à partir de patterns spatiaux de communautés. Les différentes étapes d’amélioration de ces méthodes ont également été illustrées dans la thèse au travers de trois cas d’études fournis par deux communautés d’arbres tropicale et tempérée et une communauté de champignons symbiotiques des arbres. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The savanna woodlands of Southern Africa, colloquially termed the miombo, are poorly described in terms of biodiversity compared to other biomes. They have therefore been underrepresented in the wider understanding of how land use intensification is shaping global biodiversity. Land use change is known to reduce biodiversity and disrupt intactness of ecological communities with consequences for ecosystem functioning, resilience, and services. Miombo woodlands are described as biodiversity hotspots due to a high endemism of species and the presence of megafauna. At the same time, they are also considered dynamic socio-ecological systems shaped by disturbances and the land use activities of people. The patterns of biodiversity change in these tropical ecosystems may, therefore, have their own unique contexts, understanding of which will be essential for biodiversity and land use management in these ecosystems. In this thesis, I identified the patterns of biodiversity change in response to the two major land use practices in the two dominant woodland types in southern African woodlands: the selective logging due to charcoal production in the mopane woodlands, and agricultural expansion in the miombo. I also examined the impact of two main disturbance agents, humans and elephants, on habitat structure and biodiversity in mopane woodlands. Across all chapters in this thesis, I investigated the effects of land use change and habitat modification on biodiversity empirically using chronosequences. To understand biodiversity change, I employed a hierarchical multilevel modelling approach making inferences at the three levels of ecological communities: species, community, and meta-community (set of ecological communities at different sites). I selected six villages in the charcoal production hotspot of southern Mozambique and carried out field surveys for three taxonomic groups: trees, mammals and ground beetles. I modelled the counts of trees and beetles and incidence of mammals using meta-community occurrence models in a Bayesian framework with the intensity class of the villages, above-ground biomass and land cover type as predictors. The results suggested that the species richness of trees and mammals declined by 12 and 8.5 % respectively while that of beetles increased by 3.5%, albeit non-significantly. In addition, the beta diversity of trees decreased while that of mammals increased. The results show that while both trees and mammals reduced in richness, they responded differently to charcoal production in terms of community organisation. The trees underwent subtractive homogenisation (decrease in alpha and beta diversities) primarily because of deterministic processes induced by selective harvesting of tree stems for charcoal. Mammal communities, on the other hand, showed subtractive heterogenization (decrease in alpha, but increase in beta diversity) mainly due to random extinctions. In the agriculture frontier of miombo-dominated northern Mozambique, I investigated the effects of fragmentation and habitat loss caused by agricultural expansion on diversity and composition of trees and mammals. I modelled the occurrences of trees and mammals using occupancy models with the fragmentation and quantity of woodland cover as predictors. The model showed that most tree species (n=10), mainly the timber and firewood species, linearly declined in population size as fragmentation increased. Mammals, on the other hand, showed a nonlinear response. Seven mammal species increased at the lower levels of fragmentation. However, at the higher levels, none of the mammal species increased while two declined. Similarly, the species richness of trees linearly declined, while that of mammals increased up to a fragmentation level of 55-65% and declined above this limit. The beta diversity of trees increased with fragmentation while that of mammals decreased. The results suggest that, although fragmentation reduces species richness of both trees and mammals, it affects their species compositions in different ways. Trees undergo subtractive heterogenization due to random species losses while mammals experience subtractive homogenisation mainly due to the combined effects of fragmentation-led habitat loss and intensified hunting. Finally, this study concludes that, above 75% fragmentation or below 26% habitat quantity, both taxonomic groups endure biodiversity loss. The threshold results here corroborate similar habitat quantity thresholds (20-30%) observed elsewhere in different ecosystems. However, they differ with the widespread notion that above 30% habitat quantity, the effect of fragmentation is non-existent. The results here emphasize that taxonomic groups respond differently, the diversity and population size of mammals reduced only after the habitat threshold, whereas, those of trees showed linear decrease with fragmentation most likely due to fragmentation-led habitat loss. Lastly, I examined the effects of disturbance by humans and elephants on habitat structure and bird diversity by conducting a space for time substitution comparison in the mopane woodlands of Zambia. To examine the woodland structure, I modelled the structural attributes of habitat (stem diameter, stand density, and basal area) using mixed models with the proportion of affected stems by humans and elephants as explanatory variables. I found that elephant disturbance was associated with higher stem diameters, low stand densities, but no change in basal area. Human disturbance, on the other hand, was related to reductions in stand density and basal area, but no change in the stem diameter. Further, I tested species and functional diversity of birds against the covariates of habitat structure and disturbance. I found that bird communities reduced in species richness in both, human as well as elephant disturbed areas. However, the functional diversity did not change with elephant disturbance. I concluded that human disturbance reduces woody biomass (basal area is correlated with woody biomass) of mopane woodlands and functional diversity of birds whilst elephants do not. In this thesis, I conclude that human driven land use change in the miombo woodlands erodes alpha diversity of all taxonomic groups. However, increases in beta diversity of mammals with charcoal land use and trees in agricultural land use may maintain their diversities at the meta-community level.

Thesis (MScFor)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: This study investigates how information on plant products can be used to incorporate local users into joint forest management planning by developing guidelines for sustainable collaborative management in Derre miombo woodland in the Zambézia Province in Mozambique. From the participatory appraisal, it was found that 46 woody miombo species were used in the five villages for at least 29 different purposes. Five of these species (Brachystegia boehmii, B. spiciformis, Pterocarpus angolensis, Terminalia sericea and Swartzia madagascariensis) were selected for analysis because of their multiple uses and the unknown impact of their harvesting on the future survival of those hardwood trees species. In order to determine the impact of human resource extraction on the forest and on the dynamics of tree canopy populations an inventory of woody plants was.carried out for two categories of forest land-use, namely selective harvesting and fallow land (approximately 15 years old). This was done for Golombe and Arame villages and for selective harvesting only for Mphoto village, on 23, I-ha random selected plots in the woodland adjacent to the three villages. The population structure of the five species T sericea, S. madagascariensis, P. angolensis, B. boehmii and B. spiciformis showed different trends in each of the three villages. Size class distribution of the first tree species gave evidence that the species were being harvested for building poles. This study has shown that, through plant species products, miombo contribute to the livelihoods of the local communities living in Derre woodlands. In this study it was found that usually more than one species were used for one product as well as most of the species being trees with multiple uses. This study has also provided some evidence that P. angolensis and S. madagascariensis can benefit from shifting cultivation and fire, which encourages coppice regeneration. More research is required to further validate this evidence. / AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die moontlikhede wat inligting oor spesifieke plantprodukte bied, in die betrekking van plaaslike gemeenskappe in die proses van gesamentlike bosbestuurs- en beplanningspraktyke. Verder word riglyne opgestel aangaande die volhoubaarheid van die gesamentlike bestuurs- en beplanningspraktyke in die Derre miombo bosveld, in die Zambézia Provinsie in Mozambique. Inligting verkry vanuit die deelnemende opname dui aan dat in die vyf nedersettings wat ondersoek is, 46 houtagtige miombo spesies vir ten minste 29 verskillende doeleindes aangewend word. Vyf van die spesies (Brachystegia boehmii, B. spiciformis, Pterocarpus angolensis, Terminalia sericea en Swartzia madagascariensis) is geselekteer vir gebruik in analises as gevolg van hul benutbaarheid deur plaaslike inwoners en die feit dat minimale inligting beskikbaar is oor die impak van gebruik van die harde hout spesies op hul volhoubare benutting en voortbestaan. 'n Opname van houtagtige spesies is uitgevoer in areas wat val in een van twee bosgrondgebruiks kategoriee nl. areas wat selektief geoes en benut word, en braaklande (ongeveer 15 jaar oud). Dit is gedoen om die impak wat verwydering van boshulpbronne deur mense op die boomkruin populasies het, vas te stel. Die opname strategie is gevolg in 23 ha persele, uitgelê in die gebiede wat die Golombe, Arame en Mphoto nedersettings omring - in die geval van laasgenoemde nedersetting is slegs die impak van selektiewe benutting ondersoek. Die populasie struktuur van die vyf studiespesies (T sericea, S. madagascariensis, P. angolensis, B. boehmii en B. spiciformis) het verkil vir elk van die drie nedersettings wat ondersoek is. Die verspreiding van grootte klasse vir die eerste spesie, het aangedui dat die spesie vir gebruik as konstruksie pale geoes word. Die miombo bosveld plantegroei-tipe dra by tot die lewensonderhoud van plaaslike gemeenskappe in die vorm van plant produkte, in die Derre omgewing. Daar is verder gevind dat meer as een spesie dikwels vir dieselfde doel aangewend kan word en die meeste van die spesies wat benut word is boomagtig met meer as een gebruik. In die studie is verder aanduidings gevind dat P. angolensis en S. madagascariensis kan baatvind by grondverbouings praktyke wat gereeld verskuif word en ook brande, omdat beide praktyke kreupelhout regenerasie stimuleer. Verdere navorsing word egter benodig om dié bevinding te ondersteun.