Browsing by Author "Masao, Catherine A."
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Item Agricultural Commercialisation and Its Implications on Agrodiversity Management in the Drylands of Central Tanzania(African Journals Online, 2009) Liwenga, Emma T.; Kangalawe, Richard Y. M.; Masao, Catherine A.The study examines the linkages between agricultural commercialisation and agrodiversity management. It considers agricultural commercialisation an important socio-economic aspect with varied environmental implications, particularly in relation to agro-diversity management. The study was undertaken in Kondoa and Kongwa Districts, in the semiarid central Tanzania. The aim of this study was to examine the implications of agricultural commercialization on agro-diversity management, food security and the environment in general. A variety of methods were used in the study including participatory assessments techniques, field visits and household surveys. Household data was analysed using SPSS. The findings from this study indicate that for decades agricultural production in the semiarid areas of central Tanzania has been centred on production of a diverse number of crops though concentrated on sorghum and millets as the most drought tolerant grain crops. However, from the mid-1980s the balance has shifted in favour of cereal crops like maize, which has become among the major cash-earning crop. Other prominent commercial crops included pigeon peas, sunflower and simsim. Commercial crops appear to be expanding at the expense of traditional drought tolerant crops such as bulrush millet and sorghum, thereby influencing the local agro-diversity. The abandonment of some crops e.g. castor oil plants in favour of market crops also appear to affect the agrobiodiversity in the study areas. It has been found that expansion of farms is a major factor for environmental degradation through deforestation, declining soil fertility due to continuous cultivation and emergence of noxious weeds such as Striga. On the other hand agricultural commercialization appears to have been associated with improvement in food security, household income, housing conditions and education for children. However the emphasis of the less drought tolerant crops like maize in these semiarid areas makes the sustainability of the agricultural system very uncertainItem Colonization and Diversification in the African 'Sky Islands': Insights from Fossil-Calibrated Molecular Dating of Lychnis (Caryophyllaceae)(Wiley, 2016) Gizaw, Abel; Brochmann, Christian; Nemomissa, Sileshi; Wondimu, Tigist; Masao, Catherine A.; Tusiime, Felly M.; Abdi, Ahmed A.; Oxelman, Bengt; Popp, Magnus; Dimitrov, DimitarThe flora on the isolated high African mountains or 'sky islands' is remarkable for its peculiar adaptations, local endemism and striking biogeographical connections to remote parts of the world. Ages of the plant lineages and the timing of their radiations have frequently been debated but remain contentious as there are few estimates based on explicit models and fossil-calibrated molecular clocks. We used the plastid region maturaseK (matK) and a Caryophylloflora paleogenica fossil to infer the age of the genus Lychnis, and constructed a data set of three plastid (matK; a ribosomal protein S16 (rps16); and an intergenic spacer (psbE-petL)) and two nuclear (internal transcribed spacer (ITS) and a region spanning exon 18-24 in the second largest subunit of RNA polymerase II (RPB2)) loci for joint estimation of the species tree and divergence time of the African representatives. The time of divergence of the African high-altitude Lychnis was placed in the late Miocene to early Pliocene. A single speciation event was inferred in the early Pliocene; subsequent speciation took place sporadically from the late Pliocene to the middle Pleistocene. We provide further support for a Eurasian origin of the African 'sky islands' floral elements, which seem to have been recruited via dispersals at different times: some old, as in Lychnis, and others very recent. We show that dispersal and diversification within Africa play an important role in shaping these isolated plant communities.Item Crossing Barriers in an Extremely Fragmented System: Two Case Studies in the Afro-Alpine Sky Island Flora(2014) Wondimu, Tigist; Gizaw, Abel; Tusiime, Felly M.; Masao, Catherine A.; Abdi, Ahmed A.; Gussarova, Galina; Popp, Magnus; Nemomissa, Sileshi; Brochmann, ChristianThe flora on the afro-alpine sky islands is renowned for extreme fragmentation, representing a unique natural experiment in biogeography. Here we address the roles of isolation and gene flow, in particular across the narrow Rift Valley (the RV barrier) that cuts through the Ethiopian Highlands (EH), and across the vast low-lying landscape that separates EH from the East African mountains (the EH–EA barrier). We inferred the history of two species with different dispersal mechanisms, but with similar geographic ranges and habitats based on Amplified fragment length polymorphisms (AFLPs). Contrary to our predictions, we found that the populations from opposite sides of the RV barrier were less similar than those from opposite sides of the EH–EA barrier, and that only the supposedly short distance-dispersed species (Trifolium cryptopodium) showed a strong signal of secondary gene flow across the RV barrier. In the wind-dispersed Carduus schimperi, we rather found an evidence for the gene flow between differentiated populations inhabiting different EA mountains. Both species harbored little genetic diversity but considerable genetic rarity in several individual mountains, suggesting long-term isolation and bottlenecks during climatically unfavorable periods. Our genetic data corroborate a division of C. schimperi into three subspecies, but with new delimitation of their ranges, and of T. cryptopodium into two intraspecific taxa. Our findings support the idea that stochasticity may play a major role in shaping extremely fragmented ecosystems such as the afro-alpine. After initial colonization of different mountains, periods of isolation may alternate with unpredictable episodes of intermountain gene flow.Item Macrofossil evidence of Late Holocene presence of Aldrovanda vesiculosa L. in Central-Eastern Europe (Poland) and East Africa (Tanzania)(Elsevier, 2015) Gałka, Mariusz; Bergonzini, Laurent; Williamson, David; Majule, Amos; Masao, Catherine A.; Huguet, ArnaudTo date, the seeds of waterwheel plant (Aldrovanda vesiculosa) were only found in Europe, in sediments of the Eemian and Mazovian Interglacials. The absence of A. vesiculosa seeds in European Holocene deposits is probably due to unfavorable climatic conditions, i.e. lower temperature, during this period: in temperate zones, A. vesiculosa reproduces mainly in a vegetative way; it rarely blooms and only occasionally produces seeds. In this paper, subfossil seeds of A. vesiculosa were identified in two peat bogs: one (Sucha Kobyła) in SE Poland and another one (Kyambangunguru) in SW Tanzania. Single seeds of this plant were found in a peat layer from the Polish site formed after 1600 AD as well as in sediments accumulated around 440 AD in the Tanzanian one. To our knowledge, this is the first time that seeds of A. vesiculosa are found in Holocene deposits in the world. Our findings provide new data on the distribution of A. vesiculosa over the Late Holocene.Item Phylogeographic History and Taxonomy of Some Afro-Alpine Grasses Assessed Based On Aflps and Morphometry: Deschampsia Cespitosa, D. Angusta and Koeleria Capensis(Springer Link, 2013-10) Masao, Catherine A.; Gizaw, Abel; Piñeiro, Rosalía; Tusiime, Felly M.; Wondimu, Tigist; Abdi, Ahmed A.; Popp, Magnus; Gussarova, Galina; Lye, Kåre A.; Munishi, Pantaleo; Nemomissa, Sileshi; Brochmann, ChristianPhylogeographic studies in the high mountains of Africa are hampered by the limited material available, resulting in insufficient knowledge of taxonomic variation within and among closely related species. Here, we address genetic and morphological variation in three grass species, of which one (Deschampsia angusta) has been reported as narrowly endemic and vulnerable whereas Deschampsia cespitosa and Koeleria capensis are widely distributed also outside the afro-alpine region. We used amplified fragment length polymorphisms (AFLPs) to assess genetic structuring and diversity in material collected during recent field expeditions and included additional herbarium material in morphometric analyses. The plants identified as the endemic D. angusta were genetically very similar to those identified as D. cespitosa from the same mountain (Mt Ruwenzori), forming a single coherent genetic group in STRUCTURE analysis. The plants identified as D. angusta seem to represent extremes of continuous gradients of morphological variation within a single, variable species, D. cespitosa. We found that the afro-alpine material of Deschampsia consists of three genetically very distinct groups corresponding to the three mountains investigated, suggesting persistence in isolated afro-alpine refugia during one or more glacial cycles. In contrast, we found no clear genetic structure in K. capensis. This species harbored very little genetic diversity in all six mountain areas examined, and little genetic rarity except in the Ethiopian Simen Mts. This pattern may be explained by recent colonization of the afro-alpine region from a single source population or possibly by extensive recent gene flow combined with bottlenecks. We found, however, some differentiation between different K. capensis populations from Mt Kilimanjaro, corresponding to two described varieties. This study demonstrates the need for further taxonomic exploration of the enigmatic flora of the isolated afro-alpine ‘sky islands’ and highlights that different species may have conspicuously different phylogeographic histories.Item Understanding Women’s Perceptions on Agroforestry Practices for Environmental Conservation: The Case of Communities Adjacent to Kitulang’halo Forest Reserve in Morogoro Rural District, Tanzania(2015-06) Uisso, A. J.; Masao, Catherine A.; Kauzeni, A. S.To better plan for future involvement of women in the management of the environment, it is crucial to understand their perceptions on agroforestry practices for environmental conservation. The study assessed women’s perceptions on agroforestry for environmental conservation in Lubungo A and Maseyu villages which are adjacent to Kitulang’halo Forest Reserve in Morogoro Rural District. Secondary data reviews and Participatory Rural Appraisal (PRA) involving Focus Group Discussions (FGDs), Key Informant Interviews (KIIs), field observations and household interviews were used for data collection. The results of this study indicated that in both villages studied there were dominance of male headed households, married head of households, working group, small and medium household size, number of respondents completed primary education and farming activities. From the Likert scale analysis it was realized that, the perception of women on the contribution of agroforestry to environmental conservation was generally positive. However, women were highly positive (1st Rank) about the contribution of agroforestry to wind break. Furthermore, the chi-square (X2) test results showed that there was a significant relationship between household head (X2 = 8.63, p = 0.013), age (X2 = 11.227, p = 0.024) and the level of rating of the contribution of agroforestry to environmental conservation. Conversely, X2 test showed no association between marital status, education level and household size with respondent’s level of rating. For a better future management of the environment in the agricultural landscapes women should equally recognise all the environmental benefits of the agroforestry activities. Furthermore, provision of agroforestry and environmental education, accessible loan for agroforestry, seedlings and modern agricultural equipments for enhancing agroforestry practices for environmental conservation is necessary.Item Vicariance, Dispersal, and Hybridization in a Naturally Fragmented System: The Afro-Alpine Endemics Carex Monostachya and C. Runssoroensis (Cyperaceae)(Springer Link, 2016) Gizaw, Abel; Wondimu, Tigist; Mugizi, Tusiime F.; Masao, Catherine A.; Abdi, Ahmed A.; Popp, Magnus; Ehrich, Dorothee; Nemomissa, Sileshi; Brochmann, ChristianThe naturally fragmented habitat on the tallest African mountains provides a good model system to study vicariance, dispersal, and hybridization. Many mountains are separated by lowland that likely was unsuitable for high-alpine plants even during cold climatic periods. We explore the relative importance of these processes using two endemic sister species: the widespread Ethiopian/eastern East African Carex monostachya and the mainly western East African C. runssoroensis. These bog-forming sedges co-occur in some mountains and are hypothesized to hybridize. The two species were distinctly differentiated for genome-wide amplified fragment length polymorphisms (AFLPs), also in one mountain where they co-occur. However, the plants from another mountain showed strong signals of admixture. The results suggest initial divergence into one western and one northern/eastern lineage, followed by long-distance dispersal resulting in secondary contact zones. In addition within species genetic diversity was clearly structured with distinct genetic groups on some, but not all mountains. Differentiation levels varied considerably and did not always correspond to the extent of lowland habitat between mountains. The narrow Rift Valley in the otherwise nearly contiguous highlands in Ethiopia appears to present a much stronger barrier to dispersal than the extensive lowlands separating Ethiopia from East Africa. This may be a general pattern since it has been documented also for other afro-alpine species.Item Will Ngorongoro Conservation Area Remain a World Heritage Site Amidst Increasing Human Footprint?(Academic Journals, 2015) Masao, Catherine A.; Makoba, Revocatus; Sosovele, HusseinThe Ngorongoro Conservation Area (NCA) is a World’s Heritage site and Biosphere Reserve in Tanzania. It is the only protected area with multiple land use where both wildlife conservation and limited human activities are allowed. Despite such an important status, the area is experiencing ecosystem changes resulting from increasing human population, diversified livelihoods and tourism activities. This study was conducted to determine the trends and challenges of livelihood activities of the local Maasai and tourism in NCA and their implications on the ecology of the area. Household questionnaire interviews, key informant interviews, focus group discussions, direct field observations and secondary data reviews were applied. A total of 145 people from Enduleni, Oloirobi villages and the NCA Authority (NCAA) were involved in the study. To complement the socio-economic data, landsat MSS satellite images of 1990, 2000 and 2013 blocks were analysed to assess land use/cover changes occurring in the study area. Results indicate rapid human population growth rate of 5.6% and an increment of 1.1% of livestock population per annum. It is also noted that about 46% of cropland has increased in the studied villages. Furthermore, the Maasai who were historically pastoralists are changing to agro-pastoralists. The grasslands and other natural forests showed a decreasing trend. The decreasing trends in wildlife are being associated with the changing vegetation characteristics among other factors. Despite the ecological changes, the Maasai have remained uncomfortable with the restrictions over land use so far implemented by the NCAA. In addition, there has been an increasing number of tourists and facility development within the NCA. There were also differing views between the Maasai and NCAA, which might put the NCA ecosystem under serious threats questioning its future. Whether or not the NCA will remain a world heritage site depends on management measures taken, otherwise the disappearance of the NCA ecosystem is imminent.