Articles, Conference and Workshop Papers Collection

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Inventory of dalbergia melanoxylon (mpingo) in the Southern part of Tanzania: the case of Nachingwea
(2002-03) Opulukwa, Meshack J.; Hamza, K. F. S; Malende, Y. H. M. B.
The study was designed to assess the current status of Dalbergia melanoxylon (Mpingo) in Tanzania. A total of 44 sample plots (3.08 ha) were laid on public land. D. melanoxylon contributes about 4% of all total stems out of 103 tree species identified and most of them found in clusters. Out of all visited plots 36.4% had D. melanoxylon. Parameters determined include height, stems per hectare, basal area per hectare, volume per hectare and diameter class of trees. The number of stems, basal area and volume per hectare was found to be 20, 1.2m2 and 8.6m3 respectively. The stems were distributed in five diameter classes. Based on the importance of D. melanoxylon for the economy of Tanzania, it is recom- mended that national inventory for the species should be carried out in order to know the existing stock and to prescribe sustainable harvesting regimes. Licensing for logging D. melanoxylon should be based on estimates of the yield and not on the existing demand.
Properties of nesogordonia holtzh subsp hotzii (Moss) capuron: a lesser known timber species from Kilindi District, Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2009) Gillah, P. R.; Makonda, F. B. S.; Kitojo, D. H.; Ishengoma, R. C.
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.
Properties of celtiz zenkeri engel: a lesser-known timber species from Kilindi District, Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2009) Gillah, P. R.; Makonda, F. B. S; Kitojo, D. H.; Ishengoma, R. C.; Khalid, S.
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.
Timber properties of lesser known polyscias fulva (hiern) harms and allophylus abyssinicus hochst. radlk. from Iringa Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2008) Makonda, F. B. S.; Gillah, P. R.; Augustino, S.; Valentine, S.
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 and properties 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.
Some physical and strength properties of lesser known aphloia theiformis timber from Lushoto Tanga, Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2008-07-14) Gillah, P. R.; Makonda, F. B. S.; Hussein, I.; Augustino, S.; Kitojo, D. H.
Some physical and strength properties of lesser known Aphloia theiformis timber grown in and around Magamba Forest Reserve, Lushoto district, Tanga region were determined. A total of three sample trees were randomly selected and felled for this study. Test samples for moisture content, basic density and Strength properties determination were prepared and tested according to Lavers (1969), BS 373 (1957), ISO 3130 (1975), ISO 3131 (1975), ISO 3133 (1975) and ISO 3349 (1975). It was observed that Aphloia theiformis timber has a sapwood and heartwood colour ranging from creamcoloured to whitish pink resembling that of Grevillea robusta. The average basic density was 519 kg/m3 with a standard deviation of 4.2 which can be classified as medium-density timber. The basic density showed a slight decrease from butt end to top end. Regarding strength properties, Aphloia theiformis timber had a mean modulus of rupture of about 55.8 N/mm2 and modulus of elasticity of about 3854 N/mm2. The work to the maximum load was about 0.06mmN mm-3, while total work averaged 0.08mmN mm-3. The compression and shear parallel to the grain were 37.4 and 12.6N mm-2 respectively. Furthermore, all strength properties of Aphloia theiformis were positively correlated with basic density. The properties of this timber were also comparable to properties of Grevilea robusta and are always rated the same by timber dealers. While Aphloia theiformis had higher tearing strength than Grevillea robusta, the modulus of rupture and compression parallel to the grain values were comparable. Aphloia theiformis can therefore substitute Grevilea robusta in many areas of its application.
Some physical and mechanical properties of Uapaca Kirkiana, a lesser-known timber species from Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2007) Gillah, P. R.; Makonda, F. B.; Ishengoma, R. C.; Kadala, B.; Kitojo, D. H.
This study was carried out to determine some physical and mechanical properties of Uapaca kirkiana a lesser known timber species growing in public land near Iyondo Catchment Forest Reserve, Kilombero District, Morogoro, Tanzania. A total of 3 trees were used in the study. Preparation of test samples and laboratory procedure to determine some physical and mechanical properties followed standard methods. Analysis of variance was used to determine the variation between and within trees and regression analysis was used to determine relationship between wood basic density and mechanical properties. The results showed that Uapaca kirkiana has whitish sapwood and dark brown heartwood, with a mean basic density of 518.14 kg/m3. The properties of Uapaca kirkiana were as follows: modulus of elasticity (7185.69 N/mm2), modulus of rupture (59.7 N/mm2), work to maximum load (0.06 mmN/mm3), total work to failure (0.07 mmN/mm3), shear strength parallel to the grain (11.86 N/mm2), compression strength parallel to the grain (34.4 N/mm2) and cleavage strength (20.21 N/mm width). On axial direction, the modulus of elasticity, total work to failure, compression strength parallel to grain and cleavage strength were directly proportional to its basic density while modulus of rupture, work to maximum load and shear strength parallel to the grain were inversely proportional implying that Uapaca kirkiana is suitable for activities, which require high modulus of elasticity, total work to failure, compression strength parallel to the grain and cleavage strength. On radial direction modulus of elasticity, modulus of rupture, work to maximum load, compression parallel to the grain and cleavage strength were directly proportional to basic density while shear parallel to the grain was inversely proportional to basic density. Compared to Khaya anthotheca, the timber species found in the same location and market; it was found that the timber of Uapaca kirkiana had modulus of rupture and compression parallel to the grain far lower than those of Khaya anthotheca, while the work to maximum load, total work to failure, shear strength parallel to grain and modulus of elasticity were almost the same. Due to the similarity in some of their physical and mechanical properties, the wood of Uapaca kirkiana may berecommended to substitute Khaya anthotheca in wood works that require medium density wood like in decoration where colour is considered an important aspect for appearance and in cabinet, panel and furniture making though it is not adequate in high-class strength joinery.
Tree species preferred for wood fuel in brick making in Morogoro municipality, Tanzania
(i-Proclaim, 2014) Magembe, Kija Steven; Makonda, Fortunatus B. S.
This study aimed at identifying the tree species commonly used in brick making in Morogoro Municipality, Tanzania and proposing means for generation of modified energy sources that would cover the full value of forest resource production and consumption. The research approach was two- folds using; Participatory Rural Appraisal (PRA) and quantitative measurements. Results revealed that almost all brick makers in the area used fuelwood as the major energy sources. Nine (9) tree species were used in brick making, namely; Mkarati (Burkea africana), Mlama (Combretum molle), Mbiriti (Senna siamea), Muarobaini (Azadirachta indica) and Mwembe (Mangifera indica). Others were Mkaratusi (Eucalyptus spp), Mchongoma (Pithecellobium dulce) Mjohoro (Senna spectabilis) and Mkrisimasi (Delonix regia). Of these, Mkarati, Mwembe, Mlama and Mbiriti were mostly preferred, though other species were also used insignificantly. Increasing scarcity of some of other tree species meant that deforestation from the nearby forests was a common problem. To reduce deforestation in the area, use of alternative energy sources in brick making such as rice husks and bagasse are recommended. Other recommendations are the establishment of woodlots, practicing agro-forestry systems and intensive afforestation and reforestation programmes for more sustainable fuelwood use.
Basic density and strength properties of Pines in Uganda
(African Journals Online (AJOL), 2008-02-21) Ishengoma, R. C.; Odokonyero, G.; Makonda, F. B.; Hamza, K. F.
Basic density and strength properties and their variations in 25 year - old Pinus caribaea, P. oocarpa and P. kesiya grown in Katugo, Uganda were investigated. Six trees for each species were selected representing three diameter classes. The trees were felled after measuring their diameter at breast height. Three disks were cut from each tree at 1.3 m, 45% and 75% of total tree height for growth ring width and basic density assessment. For strength properties determination, a central plank measuring 65 mm thick was extracted from each sample tree starting at breast height upwards. Basic density was determined using water displacement. Tests of various strength properties were done in accordance with standard procedures. The data were analyzed using the Statistical Analysis System. Results for the studied properties of Pinus caribaea, P. kesiya and P. oocarpa respectively were as follows: Basic density: 424, 431,and 444 kg/m3; Modulus of rupture: 54.51, 56.31 and 60.69 N/mm2; Modulus of elasticity: 8590,8752 and 8825 N/mm2; Work to maximum load: 0.088. 0.099 and 0.101 mmN/mm3; Maximum compression strength: 33.38, 33.83and 34.66 N/mm2; Maximum shear strength: 9.43, 9.80 and 10.37 N/mm2 and cleavage: 11.79,12.15 and 12.48 n/mm. There were no significant differences in all wood properties between the three species. Between tree variations in wood properties were statistically insignificant (p<0.05) in all the species, indicating a low potential of improving wood quality through selection. Growth rate had no significant influence on wood properties. Wood properties studied decreased significantly from stump upwards the stem and increased from pith outwards in the three species. Strength properties of the three pine species were strongly correlated to basic density with regression coefficients (R2) of above 0.88. Wood strength property values obtained in this study were within the range of pines grown in Kenya and Tanzania. These findings indicate that there are possibilities of expanding the use of these species through promotion. Butt end logs and inner wood can be used for non-structural applications and the outer wood for structural purposes.
Determination of basic density and strength properties of Cordia Africana Lam. Grown in agroforestry system in Lushoto, Tanga
(Tanzania Journal of Forestry and Nature Conservation, 2004) Hamza, K. F.S.; Makonda, F. B. S.; Mwamakimbullah, R.; Said, A. S.
Basic density and strength properties of Cordia africana Lam. grown in agroforestry systems in Lushoto, Tanga were determined. Six sample trees were randomly selected in the same farm at Shashui village near Soni. After measuring dbh the trees were felled and total tree height recorded. Four discs were cut at breast height, 30%, 60% and 90% of the total tree height for basic density determination. A one metre long log was cut above 1.3m for strength properties determination. A central plank measuring 6cm including pith was sawn in east-west direction from each log. Standard methods were used in determination of basic density and strength properties. The main findings of this study were as follows: Basic density was 0.40g/cm3; Basic density increased moderately from the pith to a certain point after which it remained more or less constant; Basic density decreased from the butt to the top of the tree. Mean values for modulus of rupture, modulus of elasticity, maximum crushing stress and shear parallel to grain, compression stress and cleavage perpendicular to grain were lower than those for common hardwoods such as Ocotea usambarensis and Albizia spp. found in Lushoto. There was positive correlation between basic density and strength properties. It was recommended that, wood from C. africana grown in Lushoto and other areas with similar soil and climatic conditions could be used for light construction work and furniture making. It was further recommended that, more studies should be done in other geographical conditions where the species is grown so as to make concrete conclusions on efficient utilization of the species.
Tanzania’s forest policy and its practical achievements with respect to community based forest management
(2007-02) Hamza, K. F. S.
Climate change perceptions and adaptation strategies by forest adjacent communities in Kilombero district Tanzania
(Journal of Environment and Earth Science, 2016) Balama, Chelestino; Augustino, Suzana; Eriksen, Siri; Makonda, Fortunatus B.S.
Climate change is a global challenge to both sustainable livelihoods and economic development. Tanzania has been affected by climate change due to primary dependence on rain-fed agriculture. Despite several studies being able to explore climate change farmers’ perceptions and adaptation in Tanzania, little attention has been to humid areas specifically forest adjacent communities. This study assessed the perceptions and adaptation strategies developed by forest adjacent communities against climate change effects in Kilombero District, Tanzania. Data collection involved use of household questionnaire, key informant interviews, focus group discussions and participant observations. Results showed that the majority of communities perceive the climate to have changed as evidenced by increase in temperature and unpredictable rainfall over the past decades. This was further evidenced by frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources, emergence of new pests and diseases, and fluctuations in fruiting and flowering seasons for plant resources in the forests. The communities’ perceptions are in line with existing empirical climate data for Kilombero meteorological station where temperature and rainfall have indicated an increasing trend with fluctuations in some years. The perceived change in climate has impacted different sectors mostly agriculture as the main livelihood source. Local communities are responding through different coping and adaptation strategies, such as crop diversification, changing cropping calendar, adopting modern farming technologies, increasing reliance on Non-Timber Forest Products (NTFPs), animal rearing and petty trading. Household size, residence period, land ownership, and household income were the socio-economic factors that influenced coping and adaptation strategies positively and significantly. In conclusion, forest adjacent communities perceive the climate to have changed as evidenced by different climatic indicators. In actual fact the area seem to have experienced climate variability and communities have responded differently by developing both coping and adaptation strategies within the farming and non-farming context. The study recommends a need for provision of weather forecast to the area for preparedness. The need for daily recording of climatic events by meteorological stations in the study area and other places in Tanzania is crucial for future confirmation of climate change. The observed potential coping and adaptation strategies need to be prioritized, strengthened and developed to ensure livelihood sustainability in future.
Forest adjacent households’ voices on their perceptions and adaptation strategies to climate change in Kilombero District, Tanzania
(Springer Plus, 2016) Balama Chelestino; Augustino Suzana; Eriksen Siri; Makonda Fortunatus B. S.
Climate change is a global and local challenge to both sustainable livelihoods and economic development. Tanzania as other countries of the world has been affected. Several studies have been conducted on farmers’ perceptions and adaptation to climate change in the country, but little attention has been devoted to forest adjacent households in humid areas. This study assessed this gap through assessing forest adja- cent households’ voices on perceptions and adaptation strategies to climate change in Kilombero District, Tanzania. Data collection involved key informant interviews, focus group discussions and household questionnaires. Results showed that the majority of households perceived changed climate in terms of temperature increase, unpredict- able rainfall, frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources and emergence of new pests and diseases. The perceived change in climate has impacted agriculture productivity as the main liveli- hood source. Different coping and adaptation strategies are employed. These are; crop diversification, changing cropping calendar, adopting modern farming technologies, and increasing reliance on non-timber forest products. These strategies were positively and significantly influenced by socio-economic factors including household size, residence period, land ownership and household income. The study concludes that, there are changes in climatic conditions; and to respond to these climatic changes, for- est adjacent households have developed numerous coping and adaptation strategies, which were positively and significantly influenced by some socio-economic factors. The study calls for actual implementation of local climate change policies and strate- gies in order to enhance adaptive capacity at household level.
Modelling and mapping forest above-ground biomass using earth observation data
(Science Publishing Group, 2022) Madundo, Sami Dawood; Mauya, Ernest William; Lolila, Nandera Juma; Mchelu, Hadija Ahmed
Accurate information on above-ground biomass (AGB) is important for sustainable forest management as well as for global initiatives aimed at combating climate change in the Tropics. In this study, AGB was estimated using a combination of field and Sentinel-2 earth observation data. The study was conducted at Magamba Nature Reserve in Lushoto district, Tanzania. Field plot-based AGB values were regressed against eighteen Sentinel-2 remote sensing variables (bands and vegetation indices) using Random Forest (RF) models based on centroid and weighted approaches. Results showed that the weighted model had the highest fit and precision (pseudo-R 2 = 0.21, rRMSE = 68.23%). A prediction map was produced with a mean AGB of 223.47 Mg ha -1 which was close to that of the field (225.19 Mg ha -1 ). Furthermore, the standard deviation of the AGB obtained from the map (i.e 174.04 Mg ha -1 ) was relatively lower as compared to the one obtained from the field-based measurements (i.e 97.42 Mg ha -1 ). This study demonstrated that Sentinel-2 imagery and RF-based regression techniques have potential to effectively support large scale estimation of forest AGB in the tropical rainforests.
Applications and challenges of information and communication technology in the forest sector: a case study of Morogoro municipality, Tanzania
(Science Publishing Group, 2022) Ahmad, Mchelu Hadija; William, Mauya Ernest; Juma, Lolila Nandera; Dawood, Madundo Sami
In Tanzania there is rapid adoption of Information and Communication Technology (ICT) in the forest sector and other allied sciences. Many of the uses of ICT in the forest sector are relatively new or still on the horizon and majority are not documented. Despite that, studies on the application and challenges of ICT in the forest sector of Tanzania are still limited to up to date. This study was conducted in Morogoro Municipality to document the current application and challenges of ICT in the forest sector. Data on awareness, type of professional experts with ICTs based, ICTs application domain in forest, infrastructures, software used and outputs were collected from different forest institutions located in Morogoro Municipality using structured questionnaires. Descriptive statistics of the parameters were done using Statistical Package for Social Science (SPSS) and R statistical package. The results have shown that, there is a promising trend towards applications of ICT in the forest sector, where about 75% of the respondents were aware of the ICT applications, while 25% were not. There were eight types of professionals in the forest sector with background in ICT’s based technology with higher application on data storage and analysis, documentation and forest inventory. The main challenges observed were related to the availability of infrastructures, internet connectivity and qualified personnel.
Variation of basic density and fibre length in lonchocarpus Capassa (rolfe) wood from Kilosa district, Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2016) Kayumba, I; Iddi, S; Augustino, S; Makonda, F.B.S
Within tree radial and axial variations of wood basic density and fibre length of Lonchocarpus capassa (Rolfe) were investigated using three mature defect free trees from Kilosa District, Tanzania. Samples for determination of wood basic density and fibre length were collected from the butt, the middle and the tip of the stem height and six radial positions. Wood basic density and fibre length were determined following standard procedures. The average wood basic density and fibre length were 569.3 kg m -3 and 1.38 mm, respectively. Statistical analysis indicated that stem height and radial positions had significant effect on wood density and fibre length. There was no positive linear relationship between wood basic density and fibre length. Based on density, the wood of L. capassa is heavy and is more or less comparable to that of Khaya anthotheca. The two species can therefore be used exchangeably if wood density is the only pre-requisite. Normally, heavy timbers are suitable for wood fuel from their high calorific values. The fibres of L. capassa are longer than those of the commonly used species in pulp and paper production in Tanzania, showing the potential of L. capassa for being used in pulp and paper making.
Lumber recovery and production rates of small-scale mobile sawmilling industries in northern Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2021) Lolila, N.J; Mchelu, H.A; Mauya, E.W; Madundo, S.D
This study was carried out to quantify technical efficiency of mobile sawmills by determining the lumber recovery rates and production rates of two mobile sawmills namely as Wood-Mizer (band saw machine) and Ding-dong (circular saw machine). The study was conducted in Lushoto district, located in the Northern part of Tanzania. The results indicated that Wood-Mizer had lumber recovery of 51.3% and production rate of 0.64m 3 /hr., while Ding-dong had lumber recovery rate of 35.2%, and production rate 0.86m3/hr. Generally, results have shown that both sawmills have reasonable lumber recovery rates and production rates irrespective of the differences between the two, however Wood-Mizer had great conversion efficiency compared to the Ding-dong machine. Considering the reduced supply of saw logs for sustainable forest management, a machine with high conversion efficiency is highly encouraged than machine with high speed of production, thus Wood-Mizer stands to have more chances of applications as compared to Ding-dong machine which had relatively higher production rates. However, we encourage further studies to be conducted with diverse sets of factors associated with economic aspects as well as tree species to have more baseline information on the performance of these two mobile sawmilling machineries.
Modelling and predicting measures of tree species diversity using airborne laser scanning data in miombo woodlands of Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2021) Mauya, Ernest William
In the recent decade, remote sensing techniques had emerged as one among the best options for quantification of measures of tree species diversity. In this study, potential of using remotely sensed data derived from airborne laser scanning (ALS) for predicting tree species richness and Shannon diversity index was evaluated. Two modelling approaches were tested: linear mixed effects modelling (LMM), by which each of the measures was modelled separately, and the k-nearest neighbour technique (k-NN), by which both measures were jointly modelled (multivariate approach). For both methods, the effect of vegetation type on the prediction accuracies of tree species richness and Shannon diversity index was tested. Separate predictions for richness and Shannon diversity index using LMM resulted in relative root mean square errors (RMSEcv) of 40.7%, and 39.1%, while for the k-NN they were 41.4% and 39.1%, respectively. Inclusion of dummy variables representing vegetation types to the LMM improved the prediction accuracies of tree species richness (RMSEcv = 40.2%) and Shannon diversity index (RMSEcv = 38.0%). The study concluded that ALS data has a potential for modelling and predicting measures of tree species diversity in the miombo woodlands of Tanzania.
Aboveground biomass and carbon stock of Usambara tropical Rainforests in Tanzania
(Tanzania Journal of Forestry and Nature Conservation, 2021) Mauya, E.W.; Madundo, S
Forest Above ground biomass (AGB) and carbon stock (AGC) estimation is important for carbon budget accounting, sustainable forest management as well as for understanding the role of forest ecosystem in the climate change mitigation. In the recent decade, there has been a growing global interest on quantifying AGB and AGC in the tropical countries. However, the information on AGB and AGC at local and subnational scales in most of the tropical forests is scattered and not consolidated. In this study, we reviewed the existing information on AGB and AGC for tropical rainforests of northern Tanzania. We used both data published in the peer-reviewed literature and data from unpublished sources provided by various sources. Our results showed that, there are three types of data sources and methods used for estimation of AGB and AGC. These included, field, geographical information system and remote sensing. Of all the methods, field based method was applied to a large extent. The average reported minimum values of AGB and AGC are 177.00 Mg ha -1 and 88.5 Mg ha -1 , and the maximum average values are 872 Mg ha -1 and 436 Mg ha -1 respectively. Overall, the average values of AGB and AGC in the Usambara tropical mountain forests (UTMFs) are 351.08 Mg ha -1 and 175.54 Mg ha -1 respectively. Forest structure parameters, particularly tree sizes and number of tree stems, were the major structure parameters reported to affect the amount of AGB and AGC. To conclude, the study revealed that there is a progressive trend in the estimation of AGB and AGC in the UTMFs. However, more update and effective forest survey data and methods are needed particularly in west Usambara mountain forests block.
Modeling productivity and costs of mechanized tree length skidding operations
(2021) Temba, G.P; Mauya, E.W; Shemwetta, D.T.K
Skidding operation constitute the entire process of moving felled trees from the stump site to the roadside landing. This operation normally bears substantial amount of the mill delivery costs. Thus, detailed information on productivity and cost is important for planning of cost-effective skidding operation. This study was conducted at Sao hill Forest plantation to quantify productivity and costs of tree length skidding operations. Continuous time study technique using snap-back method was used for time recording. Costs data were obtained from Mufindi Paper Mill logging department. Productivity and costs modeling, were performed using Microsoft excel. The analysis, showed that; the average productivity of the grapple skidder using tree length (TL) ranges between 398.423 m 3 /hr at a distance of 10 m and 49.862 m 3 /hr at a distance of 80 m. On the costs analysis, the unit skidding costs tends to increase with an increase of skidding distance (m) from 512.197 TZS/m 3 at a distance of 10 m to 4,092.675 TZS/m 3 at a distance of 80 m. Based on these findings it is recommended that variables distance and volume are the core factors to consider during planning to enhance efficient and costs effective skidding operation.
Properties of manilkara discolor (sond.) Hemsl.): A lesser–known Timber species from kilindi district Tanzania
(2009) Gillah, P.R; Makonda, F.B.S; Kitojo, D.H; Ishengoma, R.C; Ussiri, N.E
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.

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