Browsing by Author "Eid, T."

Now showing 1 - 9 of 9

Allometric models for prediction of above- and belowground biomass of trees in the miombo woodlands of Tanzania
(Elservier, 2013-08-02) Mugasha, W. A.; Mugasha, W. A.; Eid, T.; Bollandsås, O. M.; Malimbwi, R. E.; Chamshama, S. A. O.; Zahabu, E.; Katani, J. Z.
Miombo woodland is a significant forest type occupying about 9% of the African land area and forms a dominant vegetation type in many southeastern African countries including Tanzania. Quantification of the amount of carbon stored in forests presently is an important component in the implementation of the emerging carbon credit market mechanisms. This calls for appropriate allometric models predicting biomass which currently are scarce. The aim of this study was to develop above- and belowground allometric general and site-specific models for trees in miombo woodland. The data were collected from four sites in Tanzania and covers a wide range of conditions and tree sizes (diameters at breast height from 1.1 to 110 cm). Above- and belowground biomass models were developed from 167 and 80 sample trees, respectively. The model fitting showed that large parts of the variation (up to 97%) in biomass were explained by diameter at breast height and tree height. Since including tree height only marginally increased the explanation of the biomass variation (from 95% to 96–97% for aboveground biomass), the general recommendation is to apply the models with diameter at breast height only as an independent variable. The results also showed that the general models can be applied over a wide range of conditions in Tanzania. The comparison with previously developed models revealed that these models can probably also be applied for miombo woodland elsewhere in southeastern Africa if not used beyond the tree size range of the model data.
Allometric tree biomass and volume models in Tanzania
(Department of Forest Mensuration and Management Faculty of Forestry and Nature Conservation Sokoine University of Agriculture, 2016) Malimbwi, R.E.; Eid, T.; Chamshama, S.A.O.
None
Allometric tree biomass and volume models in Tanzania
(Department of Forest Mensuration and Management, Sokoine University of Agriculture, 2016) Malimbwi, R. E.; Eid, T.; Chamshama, S. A. O.
The publication is one of outputs of the project on "Development of biomass estimation models for carbon monitoring in selected vegetation types of Tanzania” under the Climate Change Impacts, Adaptation and Mitigation (CCIAM) programme at Sokoine University of Agriculture(SUA), The publication has multiple contributors who participated in different different specializations. The main objective of the project was to develop models and methods for assessing and monitoring carbon stocks in Tanzania required for implementation of REDD+ at local as well as national levels. Vegetation types/tree species covered were miombo woodlands, lowland and humid montane forests, mangrove forests, thicket, Acacia-Commiphora woodlands, forest plantations (Pinus patula and Tectona grandis), and coconut, cashewnut and baobab trees. For some vegetation types, both biomass and volume models were developed while for others only biomass models have been covered. For some vegetation types, both biomass and volume models were developed while for others only biomass models have been covered. The book may be useful for scholars who wish to engage in tree allometric modelling. The developed models may also be used in REDD+ estimations and other iicarbon trade mechanisms. It may also be useful to the practicing forester for determination of forest stocking levels needed for forest planning.
Biomass and volume models for different vegetation types of Tanzania
(E&D Vision Publishing Ltd, 2016) Malimbwi, R. E.; Mauya, E. W.; Zahabu, E.; Katani, J. Z.; Chamshama, S. A. O.; Eid, T.; Bollandsås, O. M.; Maliondo, S. M. S.; Mugasha, W. A.; Masota, A. M.; Njana, M.; Makero, J. S.; Mshana, J. S.; Luganga, H.; Mathias, A.; Msalika, P.; Mwangi, J.; Mlagalila, H. E.
Climate change and high rates of global carbon dioxide (CO2) emissions have increased the attention paid to the need for high-quality monitoring systems to assess how much carbon (C) is present in terrestrial systems and how these change over time. The choice of a system to adopt relies heavily on the accuracy of the method for quantifying biomass and volume as important primary variables for computing C stock and changes over time. Methods based on ground forest inventory and remote sensing data have commonly been applied in the recent decade to estimate biomass and volume in the tropical forests. However, regardless of the method, accurate tree level biomass and volume models are needed to translate field or remotely sensed data into estimates of forest biomass and volume. Therefore, the main goal of this study was to develop biomass and volume models for the forests, woodlands, thickets, agroforestry systems and some selected tree species in Tanzania. Data from destructively sampled trees were used to develop volume and above- and below-ground biomass models. Different statistical criteria, including coefficient of determination (R2), relative root mean square error (RMSE %) and Akaike Information Criterion (AIC), were used to assess the quality of the model fits. The models selected showed good prediction accuracy and, therefore, are recommended not only to support the ongoing initiatives on forest C Measurement, Reporting and Verificatio (MRV) processes but also for general forest management in Tanzania.
Decision-support tool for management of miombo woodlands: a matrix model approach
(SOUTHERN FORESTS, 2017-03-06) Mugasha, W. A.; Bollandsås, O. M.; Gobakken, T.; Zahabu, E.; Katani, J. Z.; Eid, T.
Rational forest management planning requires information on the present forest state and on future development. However, forest management planning in Tanzania has often been done without any information on forest development because appropriate tools are lacking. This study presents a matrix model that combines distance-independent growth and mortality models, area-based recruitment models, and allometric models for prediction of volume and biomass. In this way forest development can be simulated according to different treatment options. A shortterm (seven years) test of the matrix model using independent data from permanent sample plots showed that the overall difference between predicted and observed basal area was small (6.5%). Long-term simulations (1 000 years) with the model showed that it was able to attain, irrespective of initial conditions, similar steady-state conditions (i.e. basal area, volume and biomass of 13 m2 ha−1, 130 m3 ha−1 and 90 t ha−1, respectively), which also correspond well to biological expectations in the ‘real’ miombo woodlands of the country. The flexibility of the model as a decision-support tool was demonstrated by simulating three harvesting options aiming at different combinations of charcoal and timber production. The model complexity is well adapted to the data quality and abundance, and it is dependent on proxies of some main drivers of the dynamic processes. The development of the matrix model is a step forward facilitating better decisions in the management of miombo woodlands. However, data ranges used for calibrating the submodels are limited in time and space, and future efforts should focus on tests and recalibrations based on extended data ranges. Presently, therefore, applications of the matrix model should be limited to the data ranges of the modelling data from the Iringa and Manyara regions.
Forest cover changes, stocking and removals under different decentralized forest management regimes in Tanzania
(Forest Research Ins, 2013) Mongo, C.; Kashaigili, J. J.; Malimbwi, R. E.; Kajembe, G. C.; Katani, J.; Eid, T.
By the end of the last century many countries including Tanzania moved from centralised towards decentralised forest management but little empirical evidence exists on how such changes have influenced forest conditions. The objective of this study was to provide insights on how decentralised approaches might influence forest resource conditions. Forest cover analyses from satellite images (1993, 2000 and 2009) and systematic sample plot inventories (2009) in two state forest reserves under joint forest management (JFM) and two village forest reserves under community-based forest management (CBFM) in Babati District, Tanzania were carried out. Based on the results, it was not possible to claim that the decentralised management had been successful in improving forest conditions. Proportions of closed woodland decreased significantly over time (from over 80 to 50-60% under JFM and from around 70 to almost 0% under CBFM. In all forests, numbers of régénérants were high, but proportions of larger trees were low and levels of removals (legal and illegal) were relatively high. In general the situation under JFM was better than under CBFM. Results of this study can be used by policymakers to assess the influence of decentralised forest management in Tanzania.
Impact of decentralised forest management on forest resource conditions in Tanzania
(Forests, Trees and Livelihoods, 2012) Mbwambo, L.; Eid, T.; Malimbwi, R. E.; Zahabu, E.; Kajembe, G. C.; Luoga, E.
Impacts of decentralised forest management on forest resource changes were assessed. Six contrasting forest reserves regarding management regimes, that is, Joint Forest Management (JFM; in National Forest Reserves, owned by the State), Community Based Forest Management (CBFM; in village lands or general lands), and ordinary centralized state management, were selected. The forest resources were assessed by means of systematic sample plot inventories. Number of stems, basal area, volume, biomass, and carbon ha21 were compared with results from previous studies in the same reserves. Harvesting activities were also assessed as part of the sample plot inventories. In general, the results were somewhat ambiguous regarding the impacts of different management regimes. There was, however, some empirical evidence indicating that JFM and CBFM performed better than the ordinary state management, although uncontrolled exploitation of the forest has continued under decentralised forest management in the studied forests. The two regimes are promising forest decentralisation models for Tanzania, but more research is needed to understand the functions of different governance structures and how they may facilitate sustainability in both forest use and livelihoods.
Influence of forest land tenure regimes on forest condition in Uluguru mountains, Tanzania
(African Journals Online (AJOL), 2012-06) Kitula, M. H.; Kajembe, G. C.; Zahabu, E.; Luoga, E. J.; Katani, J. Z.; Ngowi, S. E.; Eid, T.
The paper scrutinizes the current wave of forest land tenure reforms since the inception of the new forest policy in 1998. It explores which type of forestland tenure regime had more positive influence on forest condition in the Uluguru Mountains, Tanzania. The assessment was done with reference to vegetation types of montane and miombo woodlands. The study showed that for the montane vegetation, state regime (Uluguru Nature Reserve) had higher stocking (volume 1,233m3/ha; basal area 78m2/ha; density 777 stems/ha) and tree species diversity (H’ 3.48) compared to communal regime (Chief Kingalu Sacred Forest) which had low stocking (volume 798m3/ha; basal area 49m2/ha; density 1,020 stems/ha) and tree species diversity (H’ 3.21). For the miombo vegetation, corporate/private regime (Tangeni Roman Catholic Church Forest Reserve) had higher stocking (volume 122m3/ha; basal area 27m2/ha and density 2,573 stems/ha) and tree species diversity (H’ 2.60) compared to communal regime (Misumba Village Land Forest Reserve) which had low stocking (volume 23m3/ha; basal area 10.8m2/ha and density 4,200 stems/ha) and tree species diversity (H’ 3.53). The study concludes that state regime represented by Uluguru Nature Reserve showed improved forest condition compared to communal tenure regime (Chief Kingalu Sacred Forest) for the montane vegetation type while private regime (Tangeni Roman Catholic Church Forest Reserve) was more effective in conservation than communal regime (Misumba Village Land Forest Reserve). The study recommends that sustainable management of forests could not be addressed by tenure reforms in the forestry sector alone, but requires 'cross-sectoral', 'inter-disciplinary' and 'participatory' approach along with secure tenure. Moreover, it is essential that an in-depth forest inventory is conducted at predetermined intervals to quantify stocking of tree, shrub species and forest disturbances to understand the level of resource extraction for each tenure regime. Key words: Tenure regimes, reforms, forest condition, Uluguru Mountains, Tanzania.
Role of communal and private forestland tenure regimes in regulating forest ecosystem goods and services in Rombo district, Tanzania
(African Journals Online, 2012) Kaniki, H. N.; Kajembe, G. C.; Zahabu, E.; Katani, J. Z.; Eid, T.
This study was undertaken to compare provisioning of forest ecosystem goods and services in Manuo Hill Communal Forest and Shirima Private Forest in Rombo District, Tanzania. Fuel wood was a key forest ecosystem good and biodiversity protection was a key forest ecosystem service identified. Manuo Hill communal forest had lower endowments values in terms of number of stems (1376 stems/ha), basal area (2.6 m2/ha), volume (7.3 m3/ha) and carbon stock (2.1 tons/ha) compared to the Shirima private forest with 2214 stems/ha, basal area of 3.2 m2/ha, volume of 11.2 m3/ha and carbon stock of 3.2 tons/ha. Only volume and carbon stock were significantly different between the forests. Species diversity was more or less similar between the forests. Tree removals were higher in communal (1.5 m3/ha) than in private (1.0 m3/ha) but they were not significantly different. Endowments in terms of tenure rights were better in communal forest than in private. More people were entitled to fuel wood from communal forest (78%) than from private (32%). Environmental benefits of biodiversity protection were entitled to everybody in both forests. It was concluded that no single tenure regime can achieve all objectives of forest management. Instead, balancing between different tenures is recommended.