45 research outputs found
Community perception on climate change and usage patterns of non-timber forest products by communities around Kilolo District, Tanzania
Climate change is currently one of the greatest environmental challenges facing humankind; where increased temperatures and changing rainfall patterns are predicted to impact upon livelihoods in Tanzania. This paper highlights the current use pattern of non-timber forest products (NTFPs) byforest-dependent communities as a strategy to cope with the impacts of climate change and variability around the New Dabaga-Ulongambi Forest Reserve (NDUFR) in Kilolo District. Specifically, the local peoples’ perceptions of climate change and the change in use pattern of NTFPs as aresponse to perceived change were investigated. Participatory Research Approaches mainly focus group discussions and household questionnaires were the methods used to collect data. The Statistical Packages for Social Science (SPSS) and content analysis were tools used to analyse data.Further, the Community-based Risk Screening Tool for Adaptation and Livelihoods (CRiSTAL 3.0) was used to synthesize information on the link between climate change, NTFPs and livelihoods. The local people perceived changes in climate based on rainfall and temperature in line with the available climatic data records from 1980 to 2011. Temperature has increased for the past 30 years; while rainfall is characterized by large inter-annual variability, with the heaviest rains in 1997 and 2010.Communities living around NDUFR are increasingly relying on NTFPs for food, health and income security among the strategy to cope with change in climate compared to the situation 30 years ago. In conclusion, climate has been varying around forest communities in Kilolo affecting their livelihood. At the same time, NTFPs seem to play safety roles by assisting communities to cope in adverse situations. There is a need for training communities on climate change issues to enhance the adaptive capacity of communities and in turn improve their livelihood. Sustainable harvesting ofNTFPs is crucial so as to reduce overexploitation of forest resources.Key words: Climate change; adaptation; NTFPs; Tanzania
Properties of Nesogordonia Holtzh subsp Hotzii (Moss) capuron: a lesser known timber species from Kilindi District, Tanzania
Nesogordonia holtzii subsp holtzii (Moss) Capuron is a lesser-known timber species belonging to the family Sterculiaceae. The species is distributed in the eastern tropical Africa in association with other tree species as Newtonia buchananii, Albizia versicolor, Allanblackia stuhlmanii, Antiaris toxicaria and Sterculia appendiculata. Currently it is harvested for fuelwood and building poles thus being under-valued, Due to its wood technical properties not known to users it is placed in royalty fee class V timbers. The objective of this study was therefore to determine and assess some basic physical and mechanical properties of N. holtzii. Compare the determined strength properties of N. holtzii with those from well known tree species. Use different combinations of the properties of N. holtzii obtained to assign suitable end uses and promote it for its utilization. Three mature sample trees free from visible defects were selected randomly. Each tree was sampled to produced three logs. Test specimens were extracted from the sample logs using the method by Larvers (1969). Physical and strength properties determination was carried out according to the procedure described in ISO 3131(1975) ISO3133 (1975) BS 373(1957, 1976) Larvers (1969) and Panshin and de Zeeuw (1970). The results showed that N. holtzii was found to have yellow timber that turns reddish brown on seasoning and the wood is fine textured. The average basic density is 593 kg m-3 Modulus of Elasticity 7,606 N/mm-3, Modulus of Rupture 81 N/mm-2, Work to Maximum Load 0.098 N mm-3, Total Work 0.196 N mm-3, Compression Stress 48.83 N mm- 2, Shear Stress 11.40 N mm-2 and Cleavage Strength 24.98 N mm-1. These properties are within the acceptable range for the building and furniture industry. As many traditional timbers become scarcer, the timber of Nesogordonia holtzii should be promoted and is recommended as a substitute for Afzelia quanzensis, Pterocarpus angolensis and Newtonia buchananii. The resemblance in colour allows these timber species to be sold in one group. Key words: Basic density – Tanga - Olea hochstteter – Brachystergia sp
Properties of Celtiz zenkeri Engel: a lesser-known timber species from Kilindi District, Tanzania
This study was conducted to provide some of the basic physical and strength properties of wood of Celtis zenkeri Engel. which is among the lesser-known and lesser-utilized timber species from Tanzania. Celtis zenkeri belonging to the family Ulmaceae is currently being harvested for wood fuel and building poles thus being under-valued and placed in class V timbers since the basic properties of its wood are not yet known. The objective of this study was therefore, to determine and assess some of the basic physical and mechanical properties of C. zenkeri specifically colour, texture, basic density, Static bending (Modulus of Flasticity, Modulus of Rupture, Work to maximum Load and Total work), Compression parallel to grain, Shear and Cleavage stress. Relationships between basic density and the mechanical properties were also assessed. Data for this study were collected from three mature and defect free sample trees objectively selected from Kilindi district in Tanga region. Each sample tree produced three logs; from bottom, middle and upper part of the bole. Test specimens were extracted from the samples and by using standard methods, the physical and mechanical properties were determined. The following are the wood strength properties obtained for C. zenkeri. Basic density (655 kg m-3) and Total Work (21,916 N mm-2), Modules of rapture (198 N mm-2), Work to maximum load (0.360 N mm-3) and Total Work (0.598 N mm-2). Others are; Cleavage strength (24.56 N mm-width), compression strength (97.1 N mm-2) and Shear strength (28.7 N mm-1) Celtis zenkeri wood was found to have desirable values to be used for hand tools, joinery, building, plywood, artificial limbs and flooring furniture.Key words: Basic density - Tanga, Khaya anthotheca, Eucalyptus paniculata, Fagaropsis angolensi
Physical and strength properties of Azadirachta indica, (a. Juss.) growing in Morogoro, Tanzania
Physical and strength properties of Azadirachta indica growing in Morogoro,
Tanzania were determined and the results compared with already known properties
of timber of the same family. The properties determined included basic density, bending strength, stiffness, work to maximum load, total work, compression and shear parallel to the grain and cleavage strength. A total of 160 test samples were used from three trees randomly selected from the study area. Preparations of test samples, actual testing and determination of different properties were carried out following standard methods. All strength property values were adjusted to 12% moisture content. Results showed A. indica to have a mean basic density of 646 kg m- 3, classified as high density timber, comparable to that of Khaya anthotheca and Trichilia emetica from the same family. The overall strength properties of A. indica are lower compared to those of K. anthotheca and T. emetica, however, superior in terms of cleavage strength. Based on the studied properties, the species can successfully substitute K. anthotheca and T. emetica in uses which require high bending, cleavage and shear parallel to the grain strengths. A. indica wood is therefore recommended for uses other than fuel wood and poles such as making furniture, tool handles, artificial limbs, joinery and plywood. Keywords: Physical properties - strength properties - Azadirachta indica - Tanzania.Tanzania Journal of Forestry and Nature Conservation Vol. 77 2008: pp. 35-4
Timber properties of lesser known Polyscias fulva (hiern) harms and Allophylus abyssinicus hochst. radlk. from Iringa Tanzania
Two lesser-known and lesser utilized timber species namely Polyscias fulva and Allophyllus abyssinicus from Iringa, Tanzania were studied to determine basic density and some strength properties. Three trees for each species were randomly selected, felled, test sampled prepared andproperties tested according to standard methods. Data analysis was conducted employing Microsoft excel computer software where descriptive statistics were computed. Analysis of variation was done to establish relationships existing between density and strength properties. Variation in basic density between trees and t-test was carried out to compare wood properties of the two species. In addition, regression analysis was used to establish the existing relationship. Tests of strength properties on clear specimens showed that on average, the overall strength properties for Polyscias fulva and Allophyllus abyssinicus were comparable respectively to Pinus caribaea and Terminalia superba, the commercially utilized timber species in Tanzania. Further, with exception of compression parallel to grain, the two species were significantly different. There was statistically significant difference within species in basic density and strength properties with exception of modulus of rupture and cleavage strength for Polyscias fulva and work to maximum load, compression parallel to the grain and cleavage for Allophylus abyssinicus. Furthermore, there were direct relationships between basic density and strength properties for the two timber species. While Pinus patula can substitute Polyscias fulva,Terminalia superba can substitute Allophyllus abyssinicus in most of its applications. The two timber species can be used for light construction work, sporting goods and furniture making. Further work on the studied species is required on other strength as well as chemical properties and natural durability.Key words: Density- strength- Terminalia superba - Pinus caribaea – Dabaga - Ulongambi fores
Properties of Albizia schimperiana oliv.: a lesser-known agroforestry timber species from Moshi rural district, Kilimanjaro Tanzania
Albizia schimperiana Oliv. is a lesser- known and lesser-utilized timber species found in the tropical eastern Africa. In Tanzania, particularly Kilimanjaro region this species is incorporated in agro-forestry systems as a shade tree for coffee. Using standard methods, this study investigated some potentials of A. schimperiana for timber. The studied properties are: i) Physical – Tree dimension, form and quality, wood colour, texture, workability and basic density ii) Strength - Static bending, compression, shear and cleavage. The average physical properties of A. schimperiana are as follows: The colour of sapwood is yellowish-white while that of heartwood is medium-brown and basic density is 455 kg m-3. The strength properties are: Modulus of elasticity (7,182 Nmm-2), Modulus of rapture (53.14 Nmm-2), Work to maximum load before failure (0.381 mmNmm-3), Compression parallel to the grain (35.5 Nmm- 2), Shear parallel to the grain (12.0 Nmm-2) and Cleavage (18.5 Nmm-2). The average strength properties are closely comparable to those of Bombax rhodognaphalon, Entandrophragma stolzii and Maesopsis eminii. With increasing scarcity of timber therefore, Albizia schimperiana can replace some uses of these traditional timber species. There is a strong relationship between basic density and strength properties except for Modulus of Elasticity. Albizia schimperiana should be promoted in agro-forestry and plantations to improve its timber availability and utilized in various uses as a substitute timber and also due to its high potential forclimate change mitigation.Key words: Mfuruanje-density-Marangu- Maesopsis eminii- Bombax rhodognaphalo
Properties of Manilkara Discolor (Sond.) Hemsl.): a lesser-known timber species from Kilindi District Tanzania
This work was conducted to determine some physical and mechanical properties of Manilkara discolor, a lesser-known and lesser-utilized timber species from Kilindi District Tanzania. Three large trees free from visible defects were selected, felled and small sample pieces of 20 mm x 20 mm x 60 mm for compression, 20 mm x 20 mm x 20 mm for shear, 20 mm x 20 mm x 45 mm for cleavage and 20 mm x 20 mm x 300 mm for static bending, comprising 72 pieces for each test were prepared. The sample pieces were tested in laboratory using standard methods. The wood was brownish and attractive, fine textured with appealing figure and attaining good finish when plained. The results showed the species to have wood basic Density of 765 kg m-3, Modulus of Elasticity of 14,341 N mm-2, Modulus of Rupture of 119.48 Nmm-2, Work to Maximum Load of 0.132 mm Nmm-2 and Work to Total Fracture of 0.284 mm Nmm-2. The Compression parallel to grain was 41.69 Nmm-2, Shear parallel to grain was 18.65 Nmm-2 and Cleavage Strength was 34.97 Nmm-2. Manilkara discolor wood was found to have desirable values and can be used to substitute other species which are currently in danger of over-exploitation.Key words: Basic density – Tanga - Khaya anthotheca - Pterocarpus angolensi
Effects of free formaldehyde emission reduction by ammonia fuming on physical and strength properties of particleboards made from formaldehyde based resins
Particleboards made using formaldehyde adhesives cause substantial emission of free formaldehyde over time. Free formaldehyde is harmful to the user’s health and it also weakens internal bonds of particleboards in use. Emissions levels of formaldehyde lie between 0.8 to 2.2 g/m3 of indoor air in particleboards constructed homes. This study was carried out to quantify the amount of free pormaldehyde in particleboards from Raiply Ltd in Eldoret, suggest possible ways to reduce the emissions and determine the effect of the treatment on physical and mechanical properties of the particleboards. Five samples were selected randomly and, different sections of the boards were prepared and soaked in distilled water for different times. Samples fumed with ammonia at different durations from 15 to 60 minutes were subsequently soaked for 1 to 24 hours to determine water absorption. High Pressure Gas Chromatography (HPGC) was used to quantify free formaldehyde present in each leachate. Ammonia treated and untreated samples were tested for both physical andmechanical properties at the Kenya Bureau of Standards. The study revealed that fuming particleboards with ammonia reduces the amount of free formaldehydes, on average, by 100%. Ammonia fuming reduces particleboards thickness swelling by between 14.01 and 11.5% and waterabsorption by between 95.6 and 90.5%. the fuming increased MOE of particleboards from 2689.9 to 3405.3 kN/mm and MOR from 10.3 N/mm to 9.3 N/mm. Ammonia fuming should therefore be used to reduce free formaldehyde emission indoor. It’s recommended that further studies becarried out to determine long-term effect of ammonia fumes on particleboards.Key words: Particleboards, ammonia fuming, formaldehyde adhesives and emissio
Comparison Of Dimensional Stability Of Particle Boards Manufactured In Tanzania And Those Imported From South Africa
Dimensional stability properties of particleboard from Tembo Chipboard Ltd, located in Tanga, Tanzania and of those imported from South Africa were determined and compared. A total of 64 test samples, 32 from Tembo Chipboard Ltd and 32 from South Africa chipboard cut randomly from boards were used for the study. Prior to the determination of the dimensional stability, moisture content and basic density of boards were determined in accordance to EN 322 and EN 323 standards respectively. Determination of dimensional stability was based on water soak test, according to EN 317 standard.
From the results, the basic densities of particleboard from Tembo Chipboard Ltd and those from South Africa were very similar at 687 and 671 kg/m3 respectively. Similarities in basic densities allowed for comparison of other properties. Thickness swelling and water absorption values of chipboards from Tembo Chipboard Ltd and S. Africa increased with increase in water immersion period. Comparatively, boards from Tembo Chipboard Ltd had lower thickness swelling and water absorption than boards from South Africa. Furthermore, less board damage due to water immersion was demonstrated by boards from Tembo Chipboard Ltd than those from S. Africa due to their low irreversible thickness swelling. The particleboards from Tembo Chipboard Ltd are more dimensionally stable than similar boards from S. Africa.
TJFNC Vol. 75 2004: pp. 54-6
108479-001 - Countering Youth Radicalization in Tunisia through Inclusion - General Background Note
The author observes convergent trends of increasing violent extremism alongside reinforced democratization since the fall of Zine al- Abidine Ben Ali in 2011. The number of Tunisians joining radical groups within Tunisia or in foreign groups raises concerns. Existing scholarship suggests that violent extremism should decline while the country moves further toward a more consolidated democracy. This background note addresses these issues, their context and history, and how youth engagement can be fostered