dissertation submitted in fulfilment of the academic requirements for the degree of Master of Science in the School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg. May 2015 / In this study I investigated the climate ecology and population biology of Brachystegia spiciformis (miombo) woodland at the distributional range edge in southern Africa. The main aim of the study was to exploit miombo relict populations, isolated well beyond contemporary distribution, to establish likely spatial and population dynamic response to future global climate change. Miombo woodlands have expanded and contracted across the central African plateau over geological time, with palynological evidence supporting an extensive latitudinal range during the Holocene altithermal. It is hypothesised that small shifts in climate may have major impacts on woodland dynamics and distribution. However, miombo relict populations in southern Africa, one in Mozambique and one in South Africa, suggest refugia; physiographic settings that support a once prevalent regional climate that has been lost (or is being lost) due to climatic shifts. Inclusion of relict populations has been shown to improve the performance of model-based projections elsewhere and have value as natural laboratories for investigating how populations react to on-going climatic change. This study aims to contribute to a better understanding of miombo woodland - an ecologically and economically significant savanna community - response to global climate change in southern Africa. A niche modelling approach was used to produce present-day and select future B. spiciformis woodland ecological niche models. Precipitation of the wettest quarter and temperature seasonality were identified as the two most important bioclimatic variables explaining B. spiciformis woodland distribution in southern Africa. Both variables displayed a relatively narrow range of optimal suitability for the species; 422 - 576 mm and 2.6 - 3.0 °C, respectively. In addition, significantly high temperature seasonality and maximum temperature of the warmest month were identified as limiting factors at the periphery of the contemporary miombo woodland distribution. Considering future regional climate change projections, it is suggested that the B. spiciformis climate niche could retract by between 30.6 - 47.3% in southern Africa by 2050. v In addition, a meta-population analysis of miombo woodland at the southern distributional range edge was carried out to elucidate patterns in population dynamics that could validate theorized climate response. Whilst the continuous miombo woodlands occurring to the north of the southern African range edge are internally relatively homogenous in community composition, relict populations reflected a loss of natural biota and a restructuring of the vegetation unit resulting in clear divergence from the core and range edge communities, and from each other. Although B. spiciformis reproduction, population density and structural dimensions were significantly low at the recently discovered relict population in South Africa relative to populations occurring to the north, we suggest that the medium-term persistence of this population is plausible based on the longevity of genets, their historic resilience, and a traditional management regime. The vicariant B. spiciformis relict population located in southern Mozambique is greater in extent than its South African counterpart and data suggest suitable reproduction dynamics for medium-term persistence. However, this population is currently heavily impacted by unsustainable habitat transformation under a lack of formal ecological or conservation protection. This study uniquely highlights B. spiciformis woodland as a climate (precipitation) sensitive component of savanna ecosystems in southern Africa and provides important baseline data for population dynamics at the distributional range edge.

Savannah ecosystems play a prominent role in the global carbon (C) cycle, yet fluxes are poorly quantified, and the key processes regulating vegetation dynamics are uncertain. Insight is particularly deficient in southern Africa’s miombo woodlands, a woody savannah that is home to over 100 million people. This biome is heavily disturbed, with widespread deforestation and degradation associated with agriculture, charcoal and timber extraction, and frequent fires from anthropogenic sources. In this thesis I combine plot inventory data with remote sensing and modelling techniques to improve our understanding of the miombo woodland C cycle. Using a network of forest inventory plots, I characterise floristic and functional diversity in a savannah-forest mosaic in southeastern Tanzania. Divergent vegetation structures are associated with variation in fire frequency, water supply, and soil chemo-physical properties. Corresponding differences are noted in fire resilience, water-use, and nutrient acquisition plant functional traits, suggesting that multiple interrelated environmental filters act to assemble heterogeneous tree communities. Re-inventory of forest plots was used to quantify key aspects of the woody C cycle. Tree growth rates are slow, calling for careful management of woodland resources, and significantly reduced where stems were damaged. Stem mortality is rare, though elevated in the smallest trees and where damage was recorded. Contemporary strategies to incentivise the conservation of miombo woodland ecosystems, such as the REDD+ programme of the United Nations, advocate payments for sustaining ecosystem services such as C sequestration. I report on a pilot REDD+ project aiming to reduce woodland degradation from frequent high intensity fires in southeastern Tanzania. Model simulations suggest that woody biomass is being gradually lost from the region, and that setting early season fires has the potential to reverse this trend. Realising substantial changes in C storage requires a demanding reduction to late fire frequency, and uncertainty in model predictions remains high. I quantify the C cycle of southern African woodlands by combining observational data with a diagnostic C cycle model under a model-data fusion framework. Model outputs show substantial variation in primary production, C allocation patterns, and foliar and canopy traits, which are associated with differences in woody cover, fire, and precipitation properties. C cycle dynamics correspond poorly to conventional land cover maps, indicating they may be unsuited to upscaling measurements and models of the terrestrial C cycle.

No description available.

Thesis (MSc)--Stellenbosch University, 2000. / Full text to be digitised and attached to bibliographic record. / ENGLISH ABSTRACT: Miombo woodland occupies the greater portion of the Zambezian phytoregion where communities derive products and services for their livelihood. The managers of these resources have for many years neglected these crucial needs, which has important implications for silvicultural systems and management interventions. The overall objective of this study was to document the miombo species utilisation preferences by local communities in Tabora, Tanzania. This information was obtained using individual interviews and village meetings. A simple line transect inventory survey was carried out to assess the miombo resources adjacent to the studied villages. The villagers in Tabora have knowledge of the importance of their woodland resources and put different species to different uses, with some overlap where a species has multiple uses. The surveyed villages differ in the utilisation of miombo resources, where the choice and quantities used depend on their proximity to urban areas. There is strong preference for suitable species for building poles and due to scarcity some people now use mud bricks for house construction. Suitable timber tree species are scarce in the Urumwa Forest Reserve and now low quality species such as Sterculia quinqueloba are used. For firewood live trees are cut and dried, however any combustible material is used. Not surprisingly the community's use priorities differ from the management priorities of the Forest Department. The use of miombo products for income generation in the studied villages is influenced by the proximity to urban areas and villagers do not perceive commercialisation of these products as depriving them of resources. The use of woodlands for cultural and religious purposes in Tabora, though important to the spiritual wellbeing of people, has declined over the years. The fact that the villagers choose particular miombo trees for different purposes is an indication of some kind of local knowledge and management. The Urumwa Forest Reserve is now an open access resource as villagers have depleted wood resources adjacent to their settlements. Awareness of the causes of miombo resource depletion in these villages is positively correlated with the proximity to urban areas and wood scarcity. Community participation in management of natural resources is still new in Tabora as few villagers were aware of the new government management interventions of the Urumwa woodlands, and awareness seems to be limited largely to males and leaders. There is active management of indigenous trees protected on farms for various uses and exotic tree-planting mainly for fruits and shade, is done around homesteads, but with no de jure rights of ownership. Tree planting in this area is severely hindered by drought, insects and termite attack to seedlings and this has made people depend entirely on the miombo for their wood requirements. The simple wood resource inventory survey carried out in this study has showed that the Urumwa miombo woodland is heavily utilised. This has resulted in poor tree diameter distribution and species composition. The smaller tree diameters recorded in the Urumwa Reserve indicate that the potential of this woodland for timber production is low compared to other products. The priority products documented in this study form base-line information for management plans and silvicultural systems suitable for sustainable management and utilisation of these woodlands in future. / AFRIKAANSE OPSOMMING: Miombo bosveld beslaan die grootste gedeelte van die Zambezi vegetasiestreek waarin 'n groot menslike bevolking produkte en dienste uit hierdie bioom genereer om 'n bestaan te maak. Bestuurders van hierdie bronne verwaarloos al jare hierdie kritiese behoeftes, en dit het belangrike implikasies vir boskundige sisteme en bestuurstussentredes. Die hoofdoel van hierdie studie was om die miombo spesiesbenutting-voorkeure van plaaslike gemeenskappe in Tabora, Tanzanië te bepaal. Inligting is bekom deur individuele onderhoude en dorpsvergaderings. 'n Eenvoudige lyn-transek opname is uitgevoer om die miombo-bronne langs die bestudeerde dorpies te bepaal. Die dorpsbewoners in Tabora dra kennis van die belangrikheid van hul bosveld bronne en gebruik verskillende spesies vir verskillende doele, met oorvleuling waar spesies meervoudige gebruike het. Die dorpies wat ondersoek is verskil in die benutting van miombo bronne waar die keuses en kwantiteite wat gebruik word bepaal word deur die nabyheid aan stedelike gebiede. Daar is 'n sterk voorkeur vir spesies geskik vir boupale en as gevolg van skaarste van die spesies gebruik sommige inwoners nou klei bakstene vir huiskonstruksie. Geskikte spesies vir die produksie van hout is skaars in die Urumwa Forest Reserve en lae kwaliteit spesies soos Sterculia quinqueloba word gebruik. Lewende bome word gekap en gedroog vir brandhout alhoewel enige brandbare materiaalook gebruik word. Dit is nie verbasend dat die gemeenskap se gebruiksprioriteite verskil van die bestuurs-prioritiete van die Departement Bosbou nie. Die gebruik van miombo-produkte vir inkomste-generasie in die bestudeerde dorpies word beinvloed deur die nabyheid aan stedelike gebiede en dorpsbewoners beskou nie dat die kommersialisering van sulke produkte hul van hulpbronne ontneem nie. Die gebruik van bosveld vir kulturele en godsdienstige doeleindes in Tabora, wat belangrik is vir die geestelike gesondheid van die inwoners, het oor die jare afgeneem. Die feit dat dorpsbewoners besondere miombo-bome kies vir verskillende gebruike is 'n aanduiding van 'n mate van plaaslike kennis en bestuur. Die Urumwa Bosreserwe is nou 'n vrye toegang hulpbron omdat dorpsbewoners houtbronne na aan hul dorpies uitgeput het. Bewustheid van die oorsake van die uitputting van miombo hulpbronne naby die dorpies is positief gekorreleerd met die nabyheid aan dorpsgebiede en houtskaarste. Gemeenskapsdeelname by die bestuur van natuurlike hulpbronne is 'n nuwe konsep in Tabora omdat min dorpsbewoners bewus is van nuwe bestuursintredes deur die regering by die Urumwa bosveld en bewustheid blyk beperk te wees tot mans en leiers. Daar is aktiewe bestuur van inheemse bome wat vir spesefieke gebruike beskerm word op plase en uitheemse boomaanplantings, hoofsaaklik vir vrugte en skadu, word by huise gemaak. Daar is geen de jure regte in die geval nie. Boomaanplantings in die gebied word ernstig beperk deur droogte, insekte en termietaanvalle op saailinge en dit veroorsaak dat mense uitsluitlik op miombo staat maak vir hul houtbehoeftes. Die eenvoudige houthulpbron-opname wat in die studie onderneem is het bewys dat die Urumwa miombo bosveld strafbenut word en dat daar geen balans tussen aanwas en hout benutting is nie. Dit veroorsaak swak boomdeursnit-verspreiding en spesies samestelling. Die kleiner boomdeursnitte wat in die Urumwa Bosreserwe aangeteken is dui daarop dat die potensiaal van hierdie bosveld vir houtproduksie laag is en slegs beperk is tot ander produkte. Die voorkeur-produkte wat in hierdie studie gedokumenteer is vorm kerninligting vir bestuursplanne en boskundige sisteme wat geskik sal wees vir die toekomstige volhoubare bestuur en benutting van hierdie bosvelde.

The tropical hardwood forests of Mozambique are among its most important natural resources. Long-term sustainable management of these resources will require proper forest management, which depends on understanding the growth rates and the life history of important commercial species as well as the impacts of natural forces (e.g., climate variability) and human management. This study analyzes radial growth rate dynamics and climate-growth relationships of Millettia stuhlmannii and examines its dendrochronological potential. This tree locally known as Panga-panga or Jambirre is one of the most important timber species in Mozambique. Ranked as a first class commercial timber in Mozambique, it is frequently harvested in an unsustainable way and sustainable management of the species is urgently needed for the continued utilization of this resource. Five different methods demonstrate that the semi-ring porous tree rings of M. stuhlmannii are annual: (1) Ring structure and anatomy; (2) Successful cross-dating within and between trees; (3) Ring counting in trees with known age (young trees collected from an experimental "plantation") (4) Cambial wounding and (5) Correlation between ring width and climate data. Through these methods, M. stuhlmannii trees showed distinct reaction to pinning, adding one annual ring after one year. Cross dating of annual ring width growth was successful within and among selected M. stuhlmannii trees, which indicates that this species forms annual rings and that growth responds to an external climate variability. M. stuhlmannii annual growth ring boundaries were characterized by alternating patterns of parenchyma and fibre vessels and marginal parenchyma. Precipitation during previous December (r= 0.30; p<0.05), current February (r=0.30; p<0.05) and the entire rainy season (NDJFM; r=0.43, p<0.01) over a long period (1900-1996) showed a significant influence on Panga-panga tree ring growth. Declining rainfall has caused a growth increment decrease since 1940. The results of this study show that the mean annual increment of M. stuhlmannii is 0.51 cm/year and it takes about 75 years for an average M. stuhlmannii tree to reach the minimum lawful cutting diameter of 40 cm DBH (diameter at breast height). Temporal differences in movement through increasing diameter classes are large among and within classes. The median time necessary for trees to grow into the next diameter class was not statistically significant (Kruskal-Wallis chi-squared = 9.568, p>0.001). The relationship between stem diameter and percentage of heartwood is significantly high (R2 = 0.9701, p < 0.0001) and results suggest that from 33cm diameters on, the HW% remain stable. Partial correlation coefficients show that significant effects on growth to minimum cutting diameter occur while stems move through the 20-30 cm DBH class. This indicates the specific sizes at which silviculture treatments have to be started in order to maximize the productivity of this species. Correlation analyses revealed that heartwood width (HW) is positively correlated with total stem diameter (TSD), cambial Age (Ac), number of rings in heartwood (HWR), heartwood area (HWA), Total stem diameter area (TSDA) and Mean annual increment (MAI). This study suggests that further studies to improve diameter growth rate models as well as volume increment models need to be carried out. Strong correlation with precipitation during the rainy season suggests that this species is potentially useful for future climate reconstruction studies in Mozambique.

Les termites représentent une part importante de la macrofaune du sol en zone tropicale. Ils peuvent jouer un rôle structurant dans les écosystèmes et servir d'indicateurs de leur santé écologique. Le miombo (forêt claire) se caractérise par la présence de grands dômes de Macrotermitinae. S'il est bien connu que ces structures abritent une flore particulière, on sait en revanche très peu de chose sur leur importance pour la biodiversité des arthropodes du sol. L’objectif principal de cette étude était d'analyser, dans un miombo du sud-ouest du Burundi, le rôle structurant éventuel des grandes termitières sur le sol et sa faune. Nous avons étudié la composition et la distribution de l'ensemble de la communauté de termites elle-même. Nous avons aussi cherché à savoir si les hautes termitières influençaient la diversité d'un autre groupe important d'arthropodes du sol, les araignées. Nous avons également caractérisé les modifications apportées par les hautes termitières aux propriétés physico-chimiques du sol. Enfin, nous avons cherché à déterminer quels facteurs, notamment édaphiques, influençaient la présence d'un termite humivore constructeur de petits nids épigés, Cubitermes pallidiceps. Vingt-cinq espèces de termites, dont 13 Apicotermitinae sans soldats, ont ainsi été recensées dans notre zone d’étude, et presque toutes se rencontrent dans les grandes termitières. Ces dernières sont érigées par Pseudacanthotermes et Odontotermes à partir de particules fines du sol, notamment du limon et de l’argile, indépendamment du pH local. Le nid érigé semble garder un taux de matière organique constant aussi longtemps qu’il est en vie. Grâce à cette teneur particulière en argile et en matière organique, les grandes termitières semblent attirer les Termitinae et Cubitermitinae. C. pallidiceps fréquente effectivement les zones du miombo où le sol est riche en argile et elle évite les sommets où le sol est généralement caillouteux et lessivé et donc pauvre en particules fines. Bien que les grandes termitières paraissent jouer un rôle important pour la diversité de la communauté de termites, ces structures semblent peu influencer la distribution des araignées. Toutefois les grandes termitières abriteraient des ressources alimentaires dont certaines espèces particulières auraient besoin.Les résultats de cette étude, une première sur la taxonomie et l’écologie des termites dans un miombo du Burundi, constituent une contribution importante dans l’enrichissement de la base de données sur les termites de l’écosystème miombo très mal connus comme dans beaucoup d’écosystèmes d’Afrique. Nos résultats pourront aussi servir de guide à l’autorité locale dans la planification de la conservation de la biodiversité dans cette région où un manque criant des données de base sur la plupart des taxons d'invertébrés reste un défi sérieux. / Termites are an important component of soil macrofauna in the tropics. They can play a structural role in ecosystems and serve as indicators of ecological health. In eastern and southern Africa, the miombo ecosystem (woodland) is characterized by the presence of large domes of fungus-growing termites (Macrotermitinae). While it is well known that these high mounds harbor a particular flora, we know very little about their importance for the biodiversity of soil arthropods.The main goal of this study was to analyse, in a miombo woodland of southwestern Burundi, the possible structuring role of large termitaria on the soil and its fauna. First, we studied the composition and distribution of the entire community of termites itself, largely unknown in the miombo as in many African ecosystems. We also investigated whether the high mounds influenced the diversity of another important group of soil arthropods, spiders. We also characterized variations in the physico-chemical properties of the soil between the high termitaria and the surrounding matrix. Finally, we tried to determine what factors, including edaphic ones, influenced the occurrence of a species of soil-feeding termite which builds small epigeous domes, Cubitermes pallidiceps.Twenty-five species, including 13 Apicotermitinae without soldiers, have been identified in our study area, and nearly all of them were present in the large mounds. These mounds are constructed by Pseudacanthotermes spiniger and Odontotermes sp. which utilize fine particles of soil, particularly silt and clay, independently of the local pH. The erected nest seems to retain a constant proportion of organic matter as long as it is alive. Due to this particular content of clay and organic matter, large termite mounds seem to be more attractive to Termitinae and Cubitermitinae. Cubitermes pallidiceps (Cubitermitinae) is effectively observed in areas of miombo where the soil is rich in clay; it avoids the peaks where the soil is stony and generally leached and therefore poor in fine particles. Even though large termite mounds appear to play an important role in the diversity of the termite community, these structures appear to have little influence on the distribution of spiders but they may harbor food resources needed by specialist species.The results of this study, the first one on the taxonomy and ecology of termites in a miombo of Burundi, is an important contribution improving of the database of termites of the miombo ecosystem in general. They can also serve as a guide to the local authorities in planning for biodiversity conservation in this region where a lack of data on most invertebrate taxa remains a serious challenge. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Experiments were carried out with the objectives of developing propagation protocols for Uapaca kirkiana and Pappea capensis tree species of southern Africa, and evaluating the graft compatibility within U. Kirkiana tree clones, provenances and species. Reverse phase high performance liquid chromatography (RP-HPLC), Folin-Ciocalteau reagent, fluorescence microscopy and callus fusion methodologies were used to diagnose graft compatibility. Results indicated that U. Kirkiana culture asepsis was achieved with 0.1% w/v mercuric chloride HgCl2) and using pre-conditioned grafted trees. Sodium hypochlorite (NaOCl) improved P. Capensis seed asepsis and germination, and discarding floating seeds improved germination. Murashige and Skoog (MS) medium with 2.0 mg l-1 benzylaminopurine (BAP) and 0.3 mg l-1 casein hydrolysate (CH) was superior in shoot multiplication and 0.5 mg l-1 indole-3-butyric acid (IBA) for rooting of P. Capensis microshoots. For somatic embryogenesis, three quarter strength MS medium with 0.05 mg l-1 thidiazuron (TDZ) and 0.3 mg l-1 CH, or 0.2 mg l-1 BAP with 0.3 mg l-1 CH, were effective in germination of P. Capensis somatic embryos. For U. Kirkiana lateral shoot explants, shoot multiplication was superior on three quarter strength MS medium with 0.1 mg l-1 BAP and 0.3 mg l-1 CH. Rooting of micro-cuttings (36%) was achieved on ½ MS with 2.5 mg l-1 IBA. RP-HPLC, fluorescence microscopy and callus fusion studies showed that phenolic compounds play a major role in U. Kirkiana graft incompatibility. Less graft compatible combinations showed an increase in phenol deposits above the union and graft incompatibility was more pronounced above the union than below the union. Proliferation of parenchymatous tissues was better below the union than above the union. Fluorescence microscopy showed presence of flavonoids and polymers above the union of less graft compatible combinations. The chromatograms showed that ferulic acid was abundant and responsible for wood discolouration. The chromatograms also isolated ρara-coumaric acids which were predominant above the union of the less compatible combinations. Therefore, ρara-coumaric acids, flavonoids and polymers were implicated in graft incompatibility of U. kirkiana trees. Copyright / Thesis (PhD)--University of Pretoria, 2008. / Plant Production and Soil Science / unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19221号 / 理博第4113号 / 新制||理||1592(附属図書館) / 32220 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 伊谷 原一, 教授 幸島 司郎, 教授 村山 美穂 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

<p>The Miombo forest is represented in seven countries in the subtropical area of Africa and is an example of ecosystem adapted to the disturbance of anthropogenic fire. The forest yields a number of different ecosystem goods and services including fuelwood, honey and soil protection. Fire has found a worldwide acceptance during the last decade due to deeper understanding of their role in the ecosystem. The presence of fire prevents up-building of fuel and big fires, therefore a new fire management is now seen.</p><p>In general the Miombo forest is threatened by overexploitation. A similar situation was represented in Duru-Haitemba forest where the case study was situated in northern Tanzania. To conserve the forest and give the tenure of the forest to the villages in Duru-Haitemba a community-based forest management was established in the middle of 1990’s. The management succeeded to save the forest with a fire management including several methods of fire preventions and now there is a well grown Miombo forest in the area. This essay deals with the topic how the fire is affecting the Miombo forest. From there, this paper examines how the current community-based forest management is formed concerning the role of fire and the objectives of the locals.</p><p>The conclusion of the essay indicates that the fire has an important role in the ecosystem of the Miombo forest and favour ecosystem dynamics and diversity of the Miombo forest.</p><p>The result of the case study showed that the fire management was poorly adapted to the disturbance of fire and was not widely based on local knowledge or specific needs and objectives of the different villages.</p>

The Miombo forest is represented in seven countries in the subtropical area of Africa and is an example of ecosystem adapted to the disturbance of anthropogenic fire. The forest yields a number of different ecosystem goods and services including fuelwood, honey and soil protection. Fire has found a worldwide acceptance during the last decade due to deeper understanding of their role in the ecosystem. The presence of fire prevents up-building of fuel and big fires, therefore a new fire management is now seen. In general the Miombo forest is threatened by overexploitation. A similar situation was represented in Duru-Haitemba forest where the case study was situated in northern Tanzania. To conserve the forest and give the tenure of the forest to the villages in Duru-Haitemba a community-based forest management was established in the middle of 1990’s. The management succeeded to save the forest with a fire management including several methods of fire preventions and now there is a well grown Miombo forest in the area. This essay deals with the topic how the fire is affecting the Miombo forest. From there, this paper examines how the current community-based forest management is formed concerning the role of fire and the objectives of the locals. The conclusion of the essay indicates that the fire has an important role in the ecosystem of the Miombo forest and favour ecosystem dynamics and diversity of the Miombo forest. The result of the case study showed that the fire management was poorly adapted to the disturbance of fire and was not widely based on local knowledge or specific needs and objectives of the different villages.