Theses and Dissertations Collection

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Implementation extent and impact of village land use planning on tree cover trends in Miombo woodland landscapes of Tanzania
(Sokoine University of Agriculture, 2024) Kilawe,Charles Joseph
Multiple social, cultural, and economic forces are causing fast land-use changes in forests. Agriculture, logging, and other human activities cause the loss of about 6 million hectares of primary forest per year around the world. Therefore, it is important to assess the trend of tree cover across time and space and the extent to which the village land use plans have been executed. The study is in line with National land policy (1995), Village Land Act No. 5 of 1999 and National Land Use Planning Act No. 6 of 2007. This study used the analysis of remote sensing data to assess trends in vegetation cover 10 years before and after land use planning in Ihombwe, Gole, and Kisegese villages located in various climatic areas in Miombo woodlands of Tanzania. Additionally, the study assessed the perception of local communities on the extent of implementation of land use planning through interviews administered to 30 households randomly selected in each village. Land use planning process was carried out in Ihombwe, Gole and Kisegese villages and remote sensing data were used to reveal the forest cover before and after the planning process. The analysis of remote sensing data revealed that tree cover was declining by 33.31%, 36.75% and 46.17% before land use planning in Ihombwe, Gole and Kisegese villages respectively. After the land use planning, there were mixed results. In areas designated for village forest reserve, there was an increase in tree cover by 9.74% and 25.23% in Ihombwe and Gole respectively. However, in Kisegese, the tree cover continued to decline, but at a slower rate of 35.42%. Outside of the forest reserves, in areas allocated for settlement, agriculture, community service, and grazing, tree cover continued to decline even after land use planning. The perception of survey participants regarding the extent of implementation of the approved village land use plan was higher in areas designated as forest reserves by 57% and 65% in Ihombwe and Gole respectively but very poor in Kisegese with 20%. Also, there was poor implementation in areas designated for grazing by 15%, 24% and 0% in Ihombwe, Gole and Kisegese respectively. Poor implementation of the land use plans was mainly constrained by the resistance of certain village inhabitants who did not approve of certain specified land use classifications and exclusion of the communities during the drafting of the plans and partly due to the lack of suitability of the land use categories. The level of involvement in the planning and implementation process varies, with Ihombwe and Gole villages showing higher participation than Kisegese to which to which the respondents were only involved in implementation of the plan. Drivers that motivated the formulation of the land use plans are mainly deforestation, immigration and occurrence of the land use conflicts. There was an increase in tree cover in forest reserves and decline outside the forest in Gole and Ihombwe, also the decline in tree cover in Kisegese, before and after land use planning. Exclusion of the communities during the drafting of the plans led to poor plans implementation. Effective conservation measures are needed to reverse the trend of forest loss and promote sustainable land use in Kisegese village. Active community engagement during planning process is needed to contribute to the alignment of land use plans with local needs and fostering ownership.
Status and progress of forest landscape restoration of the Bunduki Gap in Uluguru nature forest reserve, Morogoro, Tanzania.
(Sokoine University of Agriculture, 2024) Abdulkadir, Mohamed Ramiah
Forest Landscape restoration is a global imperative, addressing ecological, social, and climate challenges. In Africa's drylands, FAO identifies a critical need to restore 221 million hectares. In response, African nations, including Tanzania, pledged through the African Forest Landscape Restoration Initiative (AFR100) to restore 5.2 million hectares by 2030. However, the historical deforestation and degradation caused by illegal logging, agriculture expansion, and fires persist. In 2008, Tanzania government evict farmers from the Bunduki gap to enhance biological connectivity within the Uluguru nature forest reserve. Despite this, studies on the progress and composition of land cover at Bunduki post-eviction are scarce. Such information is crucial for justifying and supporting ongoing restoration initiatives amid global demands for sustainable forest management and climate change mitigation. Therefore this study assesses pre and post-eviction land cover changes at the Bunduki gap using high-resolution satellite images (Quickbird 2005, Worldview 2011, Pleiades 2017). Employing supervised image classification with a random forest algorithm on Google Earth Engine, assesses classification accuracy, analyzes changes in land cover classes, tracks their persistence and trajectories, and examines spatial distribution for the periods 2005- 2011 and 2011-2017. Vegetation composition was evaluated in terms of species richness, Important value index, diversity indices (Shannon and Simpson’s), and hierarchical clustering, while structural characteristics were analyzed in terms of diameter class distribution across forest part. The pre and post-eviction land cover assessment reveals dynamic transformations in the study area between 2005, 2011, and 2017. Forest coverage increased from 1.74% in 2005 to 51.80% in 2017, while bushland, grassland, and bare land exhibited contrasting trends. The main result is the replacement of bare land, grassland, and bushland by forest land cover. The rate of this replacement differs temporally and spatially across the gap. Vegetation composition analysis revealed 1,149 individuals representing 94 species, 47 families, and 89 genera. The majority of species (52.13%) were common across all forest part, with the Bunduki Gap exhibiting 25.53% unique species. Three distinct communities were identified, displaying significant differences (R=0.64, P<0.005), although no significance difference was observed in diversity indices (P>0.005). Diameter class distribution of the shared and unique species with high importance value index varies significantly across forest part (P < 0.0438), with higher diameter classes prevailing in Uluguru North and South, and lower and medium classes more prevalent in the Bunduki Gap, albeit with fewer instances in Uluguru North and South respectively. The study concludes there is successful forest recovery post eviction and there are similarities in emerged plant species across the forest part with varying diameter distributions, the presence of unique species and distinct communities underscores the imperative for further investigation to mitigate the spread of invasive species within the reserve
Assessment of germination behaviour and nursery performance of pericopsis angolensis
(Sokoine University of Agriculture, 2024) Mbailwa, Yahya Said
Successful tree planting and forest restoration efforts often rely on nursery practices to ensure the successful germination, growth, and survival of tree species. However, indigenous tree species like Pericopsis angolensis have received limited attention in terms of establishment, management, and performance in nursery settings, despite their significant ecological and socio-economic importance. This study investigated the influences of two major aspects of tree seedling establishment practices: seed pretreatments and seedling production techniques to provide a comprehensive understanding of optimizing nursery practices for Pericopsis angolensis seedlings in forest restoration. Seed germinability of Pericopsis angolensis was assessed through a germinability test using a complete randomized block design (CRBD) with four replications and five pre-treatments, involving soaking in normal and boiling water at different time intervals. Germination value, germination percent, mean germination time, germination index and germination capacity were used as potential indicators for seed germinability. A CRBD with a 3 x 3 x 3 factorial arrangement was employed to assess seedling performance under varying nursery conditions, including shading intensities (SIs) (0%, 50%, and 75%), pot sizes (PSs) (10 cm, 15 cm, and 20 cm), and potting mixtures (PMs) (PM0 [sand: cow manure: forest topsoil (1:2:4)], PM1 [sand: cow manure: forest topsoil (1:2:3)], PM2 [sand: cow manure: forest topsoil (1:4:3)], PM3 [forest topsoil only], and PM4 [PM0 with an additional 5 gm of NPK]). Performance of tree seedlings was assessed using growth parameters namely leaf counts, root collar diameter, root length, shoot height, total dry biomass, survival percentage, and seedling quality in terms of sturdiness quotient. This study showed that germinability was higher in the control treatment, indicating that pre-treating Pericopsis angolensis seeds by soaking in cold and hot water had no additional effect on germination. On the other hand, SI was found to significantly affect growth parameters, with 75% SI having the most substantial impact. PS and PM composition also played crucial roles, with larger pots and the use of forest topsoil contributing to increased seedling productivity. While suggesting that forest restoration using Pericopsis angolensis seeds may not require such pre-treatments, this study recommended maintaining 50% SI to optimize seedling growth and highlighted the benefits of larger PS and the inclusion of forest topsoil for biomass production. The duration for both experiments of seed pre-sowing treatments and nursery techniques were 28 days and 4.5 months respectively. In conclusion, the findings underscore the importance of careful nursery management for Pericopsis angolensis, an indigenous tree species critical for forest restoration, ultimately contributing to the conservation and restoration of vital ecosystems.
The contribution of agroforestry to household food security and income generation of the local communities in Arumeru district, Arusha, Tanzania
(Sokoine University of Agriculture, 2013) Kessy, Pamela Ezrom
The present study was conducted in Arumeru District, Arusha Region, with the objective of assessing the contribution of agroforestry to household food security and income generation of the local communities. The methods involved stratification of the district into three agro-ecological zones, randomly selecting two wards per each agro-ecological zone, one village per each ward and twenty households from each village to form a total of six wards, six villages and 120 households. Data collection was done through reconnaissance, social and field surveys. Results indicated that 71% and 59% of the households in Arumeru District depend on agroforestry as their main source of food and income livelihood respectively. Agrosilvopastoral system constituted 78% of all agroforestry practiced in the district and 33% of the agroforestry practices being of homegardens technology. The results indicated further that agroforestry contributed 89% to food security and 84% to income generation of the households of the local communities. It is concluded that besides being the most important source of peoples’ food security and income generation in the district, agroforestry has the advantages of increasing, multiplying and diversifying the per unit resources management products while holding the capacity to spread the systems outputs over different seasons of the year, which are significant attributes for assured food, income and nutrition sustainability. The availability of good road network and soil fertility were the most important enhancing factors for agroforestry adoption, drought and lack of knowledge are the most significant limiting factors while provision of water for irrigation and extension services were required interventions in improving the performance of agroforestry in the district. The study recommends for more vigorous promotion of agroforestry practices in the district by paying more attention to the indicated factors influencing and required interventions for its enhanced adoption and contribution to food security and income generation of the communities of Arumeru District.
Interaction between indigenous and external knowledge in influencing adaptation to climate change impacts among communities of North Pare mountains, Tanzania
(Sokoine University of Agriculture, 2013) Ponera, Scola Kevin
This study aimed at assessing the interaction between indigenous and external knowledge in influencing adaptation to climate change among communities in North Pare Mountains. Specifically, the objectives of the study were to: (i) assess the local knowledge on climate change, indigenous and externally influenced practices for adapting to climate change (ii) assess the effects of interaction between indigenous and external knowledge systems for adapting to climate change; and (iii) determine socio-economic factors influencing adoption of external practices for adapting to climate change. Information was obtained by using structured household questionnaire administered to 103 sampled households, PRA (focus group discussion and key informant interviews) and participant observations. Qualitative information was analyzed using content analysis which is a set of methods for analyzing symbolic content of any communication. Quantitative data were processed and analysed using Statistical Package for Social Sciences (SPSS) while logistic regression analysis was used to establish the relationship between the extent of adoption of external practices and socio-economic/demographic factors. Results show that 52.2% of respondents see drought as an indicator of climate change. Other indicators mentioned were seasonal variation in rainfall, increasing air temperature and floods. Communities use externally influenced practices such as planting exotic tree species and crops, and modem water storage systems. Majority of the community use externally influenced practices and a combination of indigenous and externally influenced practices. Age, education level and income significantly influenced adoption of externally introduced practices. It is concluded that local adaptation to climate change will continue being influenced by both indigenous and externally driven knowledge. Harnessing the potential of indigenous knowledge and its interaction with external (professional) knowledge is paramount in building a climate resilient community in the north Pare Mountains. Therefore measures to enhance the indigenous adaptive capacity and its interactions with external knowledge are necessary. Further education on climate change and its impacts is necessary so as to increase the comnjunities* resilience to climate change impacts.
Plant species composition and restoration potential through soil seed bank in Zaraninge and Mbwebwe Coastal Forests, Bagamoyo district, Tanzania
(Sokoine University of Agriculture, 2009) Pima, Nancy Eliad
The aim of the study was to assess plant species composition and its relation with soil seed bank as a basis for forest restoration through natural regeneration in Zaraninge and Mbwebwe coastal forests, Bagamoyo District Tanzania. Eighteen sample plots of size 0.07 ha were established systematically along transect in each of the two forests. Soil samples were collected within each plot at 0-10cm, 10-20cm and 20-30cm depths. The analysis was based on Importance Value Index computed from the average of relative basal area, density and frequency. Soil samples were analyzed for seed density of different plant species at the different depths. 62 and 50 plant species were identified in Zaraninge and Mbwebwe forests respectively. Out of 62 vascular plants identified in Zaraninge three species were rare plants, 35 common species and seven endemic to coastal forests. Mbwebwe forest had three rare plants, 26 common species and five endemic to coastal forests. The Shannon-Winner and Simpson Diversity Indices were 2.843, 0.093 and 2.5, 0.12 for Zaraninge and Mbwebwe forests respectively showing that the forests have high species diversity. The seed bank density for vascular plants was 2,782seeds m-2 and l,170seeds m-.2 and for rare plants was 103 and 68seeds m-2 for Zaraninge and Mbwebwe forests respectively. 71 seedlings emerged from all samples of the two forests, most of them being herbs and grasses. One rare plant species germinated from both forests. Majority (55%) of the seedlings emerged from 0-10cm soil layer. Based on the number of germinated seeds there was no close relationship between species composition of standing vegetation and composition of the seed bank. It is concluded that forest restoration through soil seed bank may greatly depend on seed bank at the surface soil horizons. The study suggests longer germination trial in order to capture full soil seed bank potentials.
Plant species composition and restoration potential through soil seed bank in Zaraninge and Mbwebwe coastal forests, Bagamoyo District, Tanzania
(Sokoine University of Agriculture, 2009) Pima,Nancy Eliad
The aim of the study was to assess plant species composition and its relation with soil seed bank as a basis for forest restoration through natural regeneration in Zaraninge and Mbwebwe coastal forests, Bagamoyo District Tanzania. Eighteen sample plots of size 0.07 ha were established systematically along transect in each of the two forests. Soil samples were collected within each plot at 0-10cm, 10-20cm and 20-30cm depths. The analysis was based on Importance Value Index computed from the average of relative basal area, density and frequency. Soil samples were analyzed for seed density of different plant species at the different depths. 62 and 50 plant species were identified in Zaraninge and Mbwebwe forests respectively. Out of 62 vascular plants identified in Zaraninge three species were rare plants, 35 common species and seven endemic to coastal forests. Mbwebwe forest had three rare plants, 26 common species and five endemic to coastal forests. The Shannon-Winner and Simpson Diversity Indices were 2.843, 0.093 and 2.5, 0.12 for Zaraninge and Mbwebwe forests respectively showing that the forests have high species diversity. The seed bank density for vascular plants was 2,782seeds m-2 and l,170seeds and for rare plants was 103 and 68seeds m-2 for Zaraninge and Mbwebwe forests respectively. 71 seedlings emerged from all samples of the two forests, most of them being herbs and grasses. One rare plant species germinated from both forests. Majority (55%) of the seedlings emerged from 0-10cm soil layer. Based on the number of germinated seeds there was no close relationship between species composition of standing vegetation and composition of the seed bank. It is concluded that forest restoration through soil seed bank may greatly depend on seed bank at the m-2 iii surface soil horizons. The study suggests longer germination trial in order to capture full soil seed bank potentials.
Regeneration and distribution of newtonia buchananii (baker) Gilbert & Boutique in Nilo Nature Reserve, Tanga, Tanzania
(Sokoine University of Agriculture, 2014) Mwigulu, Bernard Kuruchumila
This study was on the regeneration and distribution of Newtonia buchananii (Baker) Gilbert & Boutique in Nilo Nature Reserve (6,025 ha) located in Korogwe, Muheza and Mkinga Districts, Tanga Region, Tanzania. The vegetation survey was carried out in 30 systematically established square nested sample plot sizes of 3 m x 3 m, 10 m x 10 m, 20 m x 20 m and the entire 30 m x 30 m plot. The information recorded in each plot included: species name, diameter, altitude, slope, aspect, canopy height and the level of forest disturbance. Moreover, a soil sample was taken at the centre of each plot for examination of soil properties in the laboratory (soil water holding capacity, soil pH and organic Carbon). Analysis of inventory data was done by using logistic regression in SPSS version 12.0. The results were presented in tables and figures. The proportions of seedlings, saplings and trees showed that N. buchananii was not regenerating in all forest types. The species was randomly distributed in lowland and submontane forests but was contiguously distributed in montane forest. Furthermore, the results of binary logistic regression indicated that two parameters: altitude and soil water holding capacity significantly affected regeneration and distribution of N. buchananii (P =0.04 and P = 0.037 respectively). Overall, the model prediction accuracy was 76.7%. The odd ratio for altitude indicated that for every unit increase in altitude, the probability of encountering seedlings of N. buchananii was 50% while the odd ratio for soil water holding capacity indicated that for every unit increase in soil water holding capacity, the probability of encountering seedlings of N. buchananii was 41%. It is recommended that immediate conservation measures should be taken to improve the regeneration of N. buchananii. Also, further research is recommended for monitoring regeneration of N. buchananii.
Contribution of dryland forests to rural households livelihoods in Kishapu District, Shinyanga Region,Tanzania
(Sokoine University of Agriculture, 2010) Hatibu H.M .S
A study to estimate the extent of dryland forests contribution to rural households was conducted in Kishapu District. Specifically, sources of cash income for rural household expenditure were analysed, proportions contribution of cash and non cash of dryland forests was estimated and problems facing dryland forest management were identified and analysed. Four villages were purposely selected and households were randomly selected by proportion from each village and household categories, households were stratified by wealth. Primary data was collected from 318 households using household questionnaire survey. Qualitative data was analysed by content analysis and quantitative data was analysed by multiple regression. Study revealed that, farm income was the major source of total annual household income by 43%, livestocks (24.8%), forests (19.5%) and non-farm (11.9%). The overall total annual household income,was TAS 2 702 386 per household, dryland forests contributed TAS 190 662 as cash and TAS 336 751 as non cash which represented 7% and 12.5% of total household income respectively. Study revealed that most households (77.4%) in the study village experience shortage of forest products. All households (100%) depended on firewood as source of energy for cooking and per capital consumption was 0.7 m3. Theft of trees was the most serious problem which faces management of forests in Kishapu District, protection was suggested as a solutions. Cotton was found to be the major source of cash for small and medium household expenditure while cattle were the major source of cash for large household expenditure. The multiple regression analysis indicated farm income, forest income, non farm income, size of farm, education, household category and farm size significantly contributed to annual total household income. The study recommends introduction of improved energy saving stove, practise natural regeneration, enhancing value of gum and conducting research on domestication of plants producing valuable forest products and market research on forest products.
Forest ecosystem services and livelihood of communities around Shume-Magamba forest reserve, Lushoto, Tanzania
(Sokoine University of Agriculture, 2012) Maguzu J.
This study was conducted to assess the potential of forest ecosystem services to the livelihood of communities around Shume-Magamba Forest Reserve in Lushoto District, Tanzania. Data collection involved use of questionnaire survey, focus group discussion and researcher’s observation to acquire primary information. Data were analysed both qualitatively and quantitatively using the Statistical Package for Social Science (SPSS) computer software tool. Results revealed that, provisioning services (i.e. water, firewood, medicinal plants, food and building materials) were mostly recognised by local communities as the service provided by forest ecosystem followed by cultural services (i.e. tourism and spiritual areas). Provisioning services played greater role in people’s livelihoods by generating subsistence income for sustaining rural communities. The income generated (66%) by both men and women from provisioning services were highly used to cater for food, health and education. There was no significant difference at probability level 5% between gender and income generated from provisioning services to household livelihood in the study area. Findings showed that, task of conserving forest ecosystem to derive services involved both men and women. Men were mainly involved in forest protection and tree planting conservation aspects while women involved in law enforcement thus attaining sustainable forest ecosystem utilization. Fire incidences, planting crops near to water sources and illegal timber harvesting were observed to be the main constraints towards sustainable use of forest ecosystem services. It is concluded that, communities in the study area were highly uncertain on the potentials of forest ecosystem services to the livelihood, but in actual fact ecosystem services provide both direct and indirect benefits for household livelihoods though the income generated is low. The study recommends that, further research is needed to quantify what is in the field regarding forest ecosystem services and having formal market to ensure its sustainability.
Estimation of carbon stocks in Uchindile forest plantation, Kjlombero District, Tanzania
(Sokoine University of Agriculture, 2009) Wesaka, Ronald Makongoro
The study reported here was conducted to estimate carbon stocks in Uchindile forest plantation, Kilombero district, Tanzania. The tested hypothesis was Pinus patula and Eucalyptus saligna plantations had similar carbon sequestration. Data was collected from two main plantation species i.e. Pinus patula and Eucalyptus saligna. Stratified random sampling design was adopted. Three sample plots measuring 20 m x 20 m were established in each stand. Diameter at breast height (DBH) and height were measured for stand data estimation, especially volume. Top soil samples 0-15 cm and 15-30 cm depths were sampled. Then, total biomass and soil carbon stored in the plantation was prepared using Microsoft Excel. The CO2FIX was used to estimate biomass and soil carbon in the two plantations. Lundgren equations were used to estimate biomass in the pine plantations. For each species, stand ages selected were 4, 6, 8, and 10 years. Field data results indicated that at year 4, 6, 8, and 10 Pinus patula plantations sequestered stand biomass C of 7.48, 21.34, 42.22 and 61.48 Mg Cha1. Eucalyptus saligna plantations sequestered stand biomass C of 43.5, 137.53 and 183.71 Mg Cha’1. Pinus patula plantation had mean soil C of 81.29, 80.03, 76.76 and 76.47 Mg Cha'1 at year 4, 6, 8, and 10, respectively. Eucalyptus saligna plantation had mean soil C of 73.65, 86.06 and 77.77 Mg Cha’1 at year 6, 8 and 10. The two plantations sequestered total C of 218.18, 342.04 and 399.43 Mg Cha’1 at year 6, 8 and 10, respectively. This translates to 800.72, 1255.29 and 1465.91 Mg COjha’1, at the respective ages. Mg COzha’1 = Mg Cha’1 multiplied by 3.67. The T test indicated a very significant (P<0.05) difference in carbon sequestration between the two plantation species. Eucalyptus plantations sequestered 1.15 to 1.89 times more carbon in comparison to the pine.
Germination studies on seeds of trichilia emetica and vangueria infausta
(Sokoine University of Agriculture, 1998) Msanga, Heriel Petro
The effect of various physical seed coat scarifications and chemical treatments were studied to determine presowing prescriptions that would ensure uniform, fast and high germination in seeds of Trichi Iia emetica and Vangueria infausta. The studies involved eight 3x5 factorial model experiments arranged in a randomized block design with with 4 blocks each. For each of the two species, two different experiments were conducted in the laboratory and repeated in the nursery. The first experiment of Tri chi Iia erne t i ca involved 3 types of physical seed coat scarification and soaking the seeds in gibberellic acid (CA3) at 5 concentrations; i.e. 0, 250, 500, 750, and 1000 ppm. A second experiment involved 3 types of physical seed coat scarification and soaking the seeds in potassiun nitrate (KNO^) at 5 concentrations; i .e. 0.0, 0.2, 0.4,0.6 and 0.8%. The first study involving Vangueria infausta included 3 types of physical seed coat scarification and treatments of the seed with 5 concentration levels of hydrogen peroxide (H202); i .e. 0, 2, 4, 6 and 8%. In the second experiment, 3 types of physical seed coat scarifi- cation and soaking the seeds in 5 concentration levels of indole acetic acid (IAA); i.e. 0, 25, 50, 75 and 100 ppm were studied. Unscarified seeds of Trichi Iia emetica (without chemical treatment) atta ined cumulative germination of 29% and 35%, while seeds with complete removal of both the aril and the seed coat attained cunulative germination of 94s and 93« in the laboratory and nursery experiments respectively.
Exploitation of brachylaena liuilleiisis (silver oak) and its implication to regeneration of woody plants in Bombo west forest reserve, Korogwe, Tanzania
(Sokoine University of Agriculture, 2009) Mumwi, Damas Mkonda
This study was carried out in Bombo West Forest Reserve, Korogwe District, Tanzania to assess the extent of human exploitation of Brachylaena huillensis and its implication to regeneration of woody plants. Forest vegetation was stratified into highly, mild and least disturbed areas. Data were collected using forest inventory, questionnaire survey, discussion with key informants and participant observation. The overall average tree density of woody plants was 433 stems ha'1 while wood volume and basal area was 36.869 m3 ha'1 and 5.4 m2 ha'1 respectively. Overall average tree density of B. huillensis was 47 stems ha'1, basal area (1.813 m2 ha'1) and volume (14.068 in3 ha'1). It was observed that Brachylaena huillensis is abundant, dominant and frequently occurring in the forest reserve with Importance Value Index of 0.470 compared to the next important species Scorodophlaeus ficheri (0.545). Brachylaena huillensis was found to be heavily exploited indicating 82 stem ha'1, 2.622 m2 ha'1 and 16.376 m3 ha'1 while density distribution by dbh size classes indicated abnormal trend, which signifies poor recruitment and regeneration failure. The overall average of Brachylaena huillensis regenerants was 5076 seedlings ha'1 compared to 15 646 seedlings ha'1 of all woody plants in the forest reserve. Brachylaena huillensis is known by 95.7 % of the respondents whereby 79.7% of the respondents used the species for firewood. The species is intensively utilized as pole for buildings as mentioned by 42 % of the respondents and its poles were claimed to be durable and extremely resistant to termites. Carvings, charcoal, bush fire, trees and poles cutting are main threats of the forest reserve and B. huillensis in particular. Moreover, it was also observed in this study that the wood harvesting mainly for carvings and charcoal is an indication that B. huillensis and the forest in general are currently threatened and needs effective management strategies to control the illegal activities. It suggests that the domestication of the species on farmlands could probably reduce the pressure to the species and the forest in general.
Pollination biology of coffea kihansiensis (rubiaceae), an endemic wild coffee species in kihansi gorge forest, Tanzania
(Sokoine University of Agriculture, 2018) Bugingo, Adili
The Kihansi wild coffee. Coffea kihansiensis. is an endemic coffee species found in the understory of the Kihansi gorge forest in Tanzania. In this study, pollination biology of C. kihansiensis was assessed. The aim of the study was to understand the relationship between the flower biology of C. kihansiensis and its insect pollinators. Specifically, the study investigated flowering patterns, floral dimensions, insect visitors, pollinators, floral rewards and breeding system. A systematic sampling design was employed and three C. kihansiensis populations were used as sampling blocks. Data were collected through direct observations. direct counts, measurements and experiments. Flowering in the species exhibited a bing-bang (mast) flowering pattern and was observed to occur from mid-December through to January following short rains. C. kihansiensis flowers were visited by a wide range of insects belonging to 44 species. Bees of various species were the most abundant insect visitors on the flowers and appeared to be the most effective pollinators of C. kihansiensis. Flowers typically offer pollen and nectar to insect visitors. Insect visitors* frequencies were higher in the morning than in the afternoon and evening, and were associated with the timing of pollen and nectar release. Irrespective of species, insect visitation was higher in morning, at 1100 hr. Fruit set was high in cross pollinated flowers. The low fruit set in the absence of pollinators might be interpreted as an adaptation to low pollinator visitation rate or pollen limitation. The self-incompatibility index (1SI) was estimated to be 0.72. Results from hand-pollination and the ISI value show that C. kihansiensis is partially self-incompatible, able to reproduce through both selfing and outcrossing. It showed that pollinators play important role in enhancing the productivity of C. kihansiensis. The above findings imply that in situ conservation of C. kihansiensis must focus on monitoring the species, its insect pollinators and conservation and management of its natural habitat.
Deadwood carbon stock and stand structure characteristics in different vegetation types in Tanzania
(Sokoine University of Agriculture, 2023) Masanja, Sarafina N.
Deadwood is an important element playing an essential role in the maintenance of biodiversity, soil fertility and carbon sequestration. The amount of carbon stored in standing dead trees and other fallen woody debris alive or dead forms an important component of the carbon pools. Previous studies have estimated total carbon stocks for different land cover classes but they did not segregate deadwood in estimating carbon and none had considered levels of uncertainty estimates and the state of the woody decay. Also, there are limited information on stand structure of deadwood and how it is related to deadwood biomass. This study aimed to quantify deadwood carbon stocks in different vegetation types, the relationship between deadwood species structural diversity and deadwood carbon stock along different environmental variables. The study used dataset from National Forestry Resources Monitoring and Assessment of Tanzania (NAFORMA). The study revealed that solid deadwoods had higher carbon stocks and emission factor than rotten deadwoods whereby the estimated deadwood carbon stock ranges from 0.11 to 1.01 tC ha -1 , contributing 0.79% of the total carbon from different vegetation types. Compared to other vegetation types, forests and woodlands had higher deadwood carbon stocks and emission factor while grasslands had the lowest. Species abundance and soil moisture were positively significant related to deadwood carbon, with the highest effect shown by soil moisture while species richness and soil organic carbon had a negative significant relationship with deadwood carbon. In lowland forest, deadwood carbon stock of Brachystegia sp.-Pterocarpus angolensis (BP) community was positively significant influenced by soil moisture while in woodlands, deadwood carbon stock for Julbernardia globiflora-Pterocarpus angolensis (JP) community was negatively significant influenced by soil organic carbon and deadwood carbon stock of Dalbergia melanoxylon-Pteleopsis myrtifolia (DP) community was positively significant influenced by soil moisture. Understanding how deadwood carbon and stand structure of deadwood interact with environmental conditions contributes to the understanding of forests and woodlands carbon dynamics. Therefore, this study provides valuable insights for policymaking related to climate change mitigation, carbon accounting and effective biodiversity conservation in tropical ecosystems
Above ground biomass, land cover change and regeneration of tree species under different grazing intensities in miombo woodlands,Tanzania
(Sokoine University of Agriculture, 2024) Rugambwa, Thadei Tarcis
Tanzania's livestock sector faces challenges due to overgrazing, threatening the ecological balance of critical habitats like Miombo woodlands. This study investigates the impact of grazing pressure on land cover changes, tree biomass, and regeneration potential in these woodlands of Kilosa, Kilombero, and Handeni districts. Despite existing research on the damaging effects of overgrazing, a comprehensive analysis specific to Tanzanian Miombo woodlands is lacking. We address this gap by analyzing high-resolution satellite imagery (Landsat 5 TM & 8 OLI) from 1995 to 2021 to quantify land cover changes across the study areas. Field surveys were conducted to assess grazing intensity, aboveground biomass (AGB), and tree regeneration within representative Miombo woodland sites. Allometric models estimated tree-level AGB, which was then scaled to calculate plot-level AGB (tonnes/ha). Statistical analyses explored relationships between grazing intensity and land cover change, biomass dynamics, and tree regeneration. Results reveal a negative impact of medium and high grazing intensities on AGB compared to light grazing. Satellite image analysis indicates higher tree cover loss under medium grazing (63.5%) compared to high (61.5%) and light grazing (23.2%) between 1995 and 2022. Additionally, grazing intensity significantly affects tree regeneration (number, species richness, diversity, and evenness) (p < 0.05). These findings show the damaging effects of overgrazing on Tanzanian Miombo woodlands. This knowledge can inform sustainable grazing practices, collaborative management strategies, and efforts to mitigate forest cover loss. Further research could explore optimal grazing levels and develop specific recommendations for policymakers and land managers.
Effects of spacing on growth,yield and wood properties of Tectona grandis at Longuza forest plantation, Tanzania
(Sokoine University of Agriculture, 2024) Samamba, Enos.
In forest management, understanding the influence of spacing on tree growth is crucial, as it goes hand in hand with stand growth as well as yield at the final harvest. Also, spacing, especially narrow spacing, has been used to control the stem quality of trees, as it influences the stem straightness as well as the branching behaviour. On the other hand, tree growth, particularly radial growth, means an increase in wood materials such as cell wall substances, latewood, and earlywood. Those wood materials influence the physical and mechanical properties of wood. Behind those influences, an understanding of the influence of spacing on the final harvest is required to decide on appropriate spacing to economize the value of the final harvest. However, information on the spacing influence on growth, yield, and wood properties of Tectona grandis at an older age in Tanzania is limited. Thus, this study is intended to evaluate the influence of spacing on the growth, yield, and wood properties of 24-year-old Tectona grandis at Longuza Forest plantation, Tanzania. Data were collected from a spacing trial with a randomized complete block design with three treatments, namely 2 x 2 m, 3 x 3 m, and 4 x 4 m, replicated three times. For growth and stem quality, all trees' diameter at breast height (dbh), height, and stem quality were evaluated. Then, dbh data were used to obtain basal area (Ba), volume, and the mean annual increment (MAI). Furthermore, three trees from each spacing were sampled for physical and mechanical properties. The basic density (BD) was determined using over-dry weight and green volume, while the heartwood (HW) percentage was calculated using the cross-sectional area of the HW and disk underbark. Moreover, all mechanical properties were tested using a Monsanto tensiometer machine. An analysis of variance (ANOVA) was used to evaluate the influence of spacing. Then, Tukey’s Honest Significant Difference test (p = 0.05) was used for multiple comparisons of means. Results revealed that at the older age of 24 years, spacing did not statistically influence all growth and yield parameters studied. A 4 x 4 m spacing produced trees with higher dbh and height, while higher Ba, volume, and MAI values were observed at 3 x 3 m. Stem quality was statistically different in some spacings, where only 2 x 2 m differed statistically from 4 x 4 m. All physical and mechanical properties evaluated were not statistically influenced by spacing except CLST to grain, whereby the spacings of 2 x 2 m and 3 x 3 m had significantly higher values than a spacing of 4 x 4 m. In conclusion, results showed that despite the growth and yield parameters not being statistically influenced by spacing, a spacing of 3 x 3 m could ensure a higher yield compared to other spacings. Also, it produces trees with high stem quality, similar to closer spacing, without affecting both physical and mechanical properties. This is because the values of those properties appear to have slight differences among the spacings. Keywords: Tectona grandis, Spacing, Volume, Stem quality, Basic density, Heartwood percentage
Survival, growth and wood properties of eucalyptus urophylla provenances in southern highlands, Tanzania
(Sokoine University of Agriculture, 2024-05) Sangiwa, Milkajane Job
In Tanzania, commercial forestry is a developing industry that plays a key role in many important development areas, such as construction and rural electrification, it‟s also one of the strategies required to reduce the loss of natural forests and mitigating the increasing shortage of wood supply. Eucalyptus urophylla has been preferred as important forest plantation species for wood production and it‟s among the most common Eucalyptus species planted in Tanzania for commercial purposes. However, there is lack of reliable sources and diversity of the materials in the country. Tree improvement activities, like provenance testing, are essential to ensuring high-quality timber trees by identifying the best sources of a species for a given area in order to increase survival and productivity. This information is required to assist in formulating the efficient operation of a breeding programme through which the quality and productivity of plantations may be improved. The use of important economic traits during selection of the best provenances has the potential to provide valuable inputs for commercial forestry industry and conservation of breeding materials. This study aimed at evaluating the variation within the species and to determine the best seed sources for planting in the Southern Highlands of Tanzania. Specifically, the study tested the variation found in the established trial for certain economically important traits such as survival, growth, wood basic density and stem quality. From this, the study aimed to determine provenance differences between these traits. This information will be used as basis for selection of best performing provenances for future plantation establishment and genetic conservation efforts. The study‟s results showed significant differences (p > 0.05) in survival, DBH, Ht, Vol, BA, and MAI, the average values for these parameters were 90.6 %, 22.54 cm, 30.7 m, 264.85 m3ha-1, 7.61 m2ha-1, and 19.16 m3ha-1yr-1 respectively. The study identified superior-performing provenances, including provenance 40, 59, 60, 61 and 62, where majority originating from Wetar island. Furthermore, the results revealed significant variation in stem straightness among provenances with the average score of 5.0. Provenances 40, 60 and 59 had trees with superior straightness. In addition, substantial variations in BD were observed among the provenances. The average basic density was 548.31 kg/m3, with mean ranging 509.24 kg/m3 to 586.31 kg/m3. Based on the findings the study recommends planting provenances 40, 59, 60, 61 and 62 in large scale at Southern highlands of Tanzania and in areas with similar climate and soil conditions. The methodology and findings of this study can be used as a basis for developing and selecting superior provenances and progenies to improve productivity, for plantation establishment and sustainable utilization of its wood resources. Future studies and breeding efforts should be done on other important traits such as pulp yield, drought tolerance and resistance to pests and diseases. Additionally, this trial can be used for conservation of forest genetic resources by preserving the genetic diversity of the species in the country.
Infestation density and habitat suitability of tree girdling beetle, paranaleptes reticulata Thoms. (Coleoptera: Cerambycidae) in Eastern Tanzania
(Sokoine University of Agriculture, 2024-05) Nilahi, Medison Fildeline
Despite the increased rate of spread and infestation of the insect pest, Paranaleptes Reticulata Thoms among government plantations and other tree growers in Eastern Tanzania, there is limited information on the infestation patterns and suitable habitat distribution for P. reticulata. To provide this piece of information this study aimed at assessing first, infestation density and severity of P. reticulata across government plantation forests and community woodlots. Modelling the current and potential future habitat distributions of the P. reticulata in Eastern Tanzania. Data on presence of P. reticulata and number of trees infested by P. reticulata were collected from 158 plots to count and measure trees infested by P. reticulata. Also, age, diameter of infested trees and the occurrence coordinates were recorded. Non-parametric Kruskal-Wallis test was used to analyse if infestation density and severity differed between agroecological zones and species. Dunn's post hoc test was used to assess which sites and species differed from each other in terms of infestation densities and severity. Generalised linear mixed models (GLMMs) with a negative binomial error distribution and plots as a random factor was used to to assess the direction of associations between environmental variables and the infestation density and severity of species. Ensemble species distribution models combining presence records for P. reticulata and potential environmental variables was used estimated habitat suitability. Results on infestation patterns revealed that infestation density (H = 83.95, df = 3, p < 0.001) and severity (H = 50.62, df = 3, p < 0.001) differed between sites. Similarly, infestation density (H = 29.63, df = 2, p < 0.001) and severity (H = 29.63, df = 2, p < 0.001) differed between species. GLMMs indicated that tree diameter, tree age, and solar radiation were negatively associated with both infestation density and severity, while wind was positively associated with both infestation density and severity. Infestation density and extent of severity were significantly higher for Corymbia citriodora and Eucalyptus tereticornis compared to the reference species Commiphora Africana. Results on habitat suitability indicated that the highly suitable habitat for P. reticulata would decrease significantly in the year 2050 and 2090 under SSP126 and SSP585 scenarios. The study concludes that exotic species are more prone to P. reticulata infestations across sites compared to native species and climatic variables play crucial in determining current and future habitat suitability for P. reticulata. The study recommends age-, size-, and species-specific preventive measures to reduce P. reticulata infestation density and severity in Tanzania. Predictive maps could also be used by managers, planners, and tree growers to strategize, plan and making informed decision about the current and future infestations status.
Pollination efficiency of apis mellifera and hypotrigona gribodoi on capsicum annuum fruit set and yield in Morogoro region, Tanzania
(Sokoine University of Agriculture, 2024-05) Mbazi, Paschal Hotay
Pollination by insects accounts for over 70% of global food crops production. Among insect species, bees are one of the most efficient pollinators though their pollination efficiency varies between species. Amidst rising worries about declining pollinator populations due to human activities and changes in climate, comprehending diverse pollinator capabilities is crucial for conservation. While stingless bees show promise as commercial pollinators, their capacities compared to Apis mellifera remain insufficiently understood, resulting in limited domestication and thus threatening their population.. This study evaluated the pollination efficiency of Apis mellifera and Hypotrigona gribodoi on yield and fruit set in Capsicum annuum. A randomized complete block design experiment was conducted with three replications and three caged treatmentswhich are Apis mellifera, Hypotrigona gribodoi, and self-pollinated plants. Each treatment was replicated three times to assess the effects of pollination on yield and fruit set rates. We made comparison on bees' foraging activities and computed their impact on fruit set. Furthermore, we explored the influence of abiotic factors on bees foraging activities, to a comprehensive analysis of the intricate relationship between pollination, bee behavior, and environmental factors. Analysis of variance (ANOVA) was used to compare the differences in fruit quality, seed quality, and fruit set rate between the two species. Kruskal wallis was used to test for difference among data which are not normally distributed. Tukey's Honestly Significant Difference (HSD) and Dunn tests were used for normally distributed and non-normally distributed data respectively. To compare the difference in bee foraging activity, we use the Wilcoxon rank-sum test. We employed a Generalized Linear Model (GLM) to investigate the relationship between fruit set rate and foraging activity, and a Poisson Regression Model to explore the relationship between foraging activity, abiotic factors, and bee species. The results show that the number of fruits per plant, fruit transverse circumference, fruit vertical circumference, fruit weight, and percentage fruit set rate per plant were higher in the plot pollinated with Hypotrigona gribodoi, followed by Apis mellifera, and lastly the control plot and the difference was statistically significant (P < 0.05). However, there was no significant difference in the number of seeds per fruit and the weight of 100 dry seeds per fruit among the two species (P>0.05). Hypotrigona gribodoi showed higher flower visits, pollen-carrying workers, and visitors per flower than Apis mellifera, with significant differences (P < 0.001). Conversely, Apis mellifera had more exiting workers (P < 0.001). Moreover no difference in time spent on the flower (P>0.05). Also the number of workers entering with pollen (P<0.001), workers exiting the hive (P<0.001), and time spent on the flower (P<0.05) have a significant effect on the fruit set rate of Capsicum annuum. The number of visitors per flower and the number of flowers visited do not have a significant effect (P>0.05). Temperature and humidity significantly affect the number of visitors per flower, the time spent on flower and the number of workers exiting the hives. However, the number of flowers visited and the number of workers entering the hive with pollen were not influenced by temperature and humidity. These findings suggest that Hypotrigona gribodoi is a more efficient pollinator of Capsicum annuum L. Furthermore, the foraging behavior of Apis mellifera and Hypotrigona gribodoi is affected by temperature and humidity affecting the fruit set rate of Capsicum annuum. More research on the differential pollination efficiency among different bee species in crop production is imperative.

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