Browsing by Author "Zahabu, Eliakimu"

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A sampling design for a large area forest inventory: case Tanzania
(NRC Research Press) Tomppo, Erkki; Malimbwi, Rogers; Katila, Matti; Mäkisara, Kai; Chamuya, Nurdin; Zahabu, Eliakimu; Otieno, Jared; Henttonen, Helena M.
A sampling design for a large area forest inventory: case Tanzania
(NRC Research Press, 2014-04-21) Tomppo, Erkki; Malimbwi, Rogers; Katila, Matti; Mäkisara, Kai; Chamuya, Nurdin; Zahabu, Eliakimu; Otieno, Jared; Henttonen, Helena M.
Methods for constructing a sampling design for large area forest inventories are presented. The methods, data sets used, and the procedures are demonstrated in a real setting: constructing a sampling design for the first national forest inventory for Tanzania. The approach of the paper constructs a spatial model of forests, landscape, and land use. Sampling errors of the key parameters as well as the field measurement costs of the inventory were estimated using sampling simulation on data. Forests and land use often vary within a country or an area of interest, implying that stratified sampling is an efficient inventory design. Double sampling for stratification was taken for the statistical framework. The work was motivated by the approach used by The Food and Agriculture Organization of the United Nations (FAO) in supporting nations to establish forest inventories. The approach taken deviates significantly from the traditional FAO approaches, making it possible to calculate forest resource estimates at the subnational level without increasing the costs.
Above- and belowground tree biomass models for three mangrove species in Tanzania: a nonlinear mixed effects modelling approach
(Springer) Njana, Marco Andrew; Bollandsås, Ole Martin; Eid, Tron; Malimbwi, Rogers Ernest; Zahabu, Eliakimu
Above- and belowground tree biomass models for three mangrove species in Tanzania: a nonlinear mixed effects modelling approach
(Springer, 2015-10) Njana, Marco Andrew; Bollandsås, Ole Martin; Eid, Tron; Malimbwi, Rogers Ernest; Zahabu, Eliakimu
& Key message Tested on data from Tanzania, both existing species-specific and common biomass models developed elsewhere revealed statistically significant large prediction errors. Species-specific and common above- and below- ground biomass models for three mangrove species were therefore developed. The species-specific models fitted bet- ter to data than the common models. The former models are recommended for accurate estimation of biomass stored in mangrove forests of Tanzania. & Context Mangroves are essential for climate change mitiga- tion through carbon storage and sequestration. Biomass models are important tools for quantifying biomass and car- bon stock. While numerous aboveground biomass models exist, very few studies have focused on belowground biomass, and among these, mangroves of Africa are hardly or not represented.
Allometric models for estimating tree volume and aboveground biomass in lowland forests of Tanzania
(International Journal of Forestry Research) Mugasha, Wilson Ancelm; Mwakalukwa, Ezekiel Edward; Luoga, Emannuel; Malimbwi, Rogers Ernest; Zahabu, Eliakimu; Silayo, Dos Santos; Sola, Gael; Crete, Philippe; Henry, Matieu; Kashindye, Almas
Allometric models for estimating tree volume and aboveground biomass in lowland forests of Tanzania
(International Journal of Forestry Research, 2016) Mugasha, Wilson Ancelm; Mwakalukwa, Ezekiel Edward; Luoga, Emannuel; Malimbwi, Rogers Ernest; Zahabu, Eliakimu; Silayo, Dos Santos; Sola, Gael; Crete, Philippe; Henry, Matieu; Kashindye, Almas
Models to assist management of lowland forests in Tanzania are in most cases lacking. Using a sample of 60 trees which were destructively harvested from both dry and wet lowland forests of Dindili in Morogoro Region (30 trees) and Rondo in Lindi Region (30 trees), respectively, this study developed site specific and general models for estimating total tree volume and aboveground biomass. Specifically the study developed (i) height-diameter (ht-dbh) models for trees found in the two sites, (ii) total, merchantable, and branches volume models, and (iii) total and sectional aboveground biomass models of trees found in the two study sites. The findings show that site specific ht-dbh model appears to be suitable in estimating tree height since the tree allometry was found to differ significantly between studied forests. The developed general volume models yielded unbiased mean prediction error and hence can adequately be applied to estimate tree volume in dry and wet lowland forests in Tanzania. General aboveground biomass model appears to yield biased estimates; hence, it is not suitable when accurate results are required. In this case, site specific biomass allometric models are recommended. Biomass allometric models which include basic wood density are highly recommended for improved estimates accuracy when such information is available.
At the heart of REDD+: a role for local people in monitoring forests?
(Wiley Periodicals, Inc.) Danielsen, Finn; Skutsch, Margaret; Burgess, Neil D; Jensen, Per Moestrup; Andrianandrasana, Herizo; Karky, Bhaskar; Lewis, Richard; Lovett, Jon C; Ngaga, Yonika; Phartiyal, Pushkin; Poulsen, Michael Køie; Singh, S. P; Solis, Silvia; Sørensen, Marten; Tewari, Ashish; Young, Richard; Zahabu, Eliakimu
At the heart of REDD+: a role for local people in monitoring forests?
(Wiley Periodicals, Inc., 2011) Danielsen, Finn; Skutsch, Margaret; Burgess, Neil D; Jensen, Per Moestrup; Andrianandrasana, Herizo; Karky, Bhaskar; Lewis, Richard; Lovett, Jon C; Ngaga, Yonika; Phartiyal, Pushkin; Poulsen, Michael Køie; Singh, S. P; Solis, Silvia; Sørensen, Marten; Tewari, Ashish; Young, Richard; Zahabu, Eliakimu
Reduced Emissions from Deforestation and Forest Degradation in Developing Countries (REDD+) is a policy mechanism now agreed under the United Na- tions Framework Convention on Climate Change (UNFCCC). It aims to reduce carbon dioxide emissions from developing countries through the sustainable management of forests, while providing co-benefits of biodiversity conserva- tion and livelihood support. Implementation challenges include linking remote sensing and national forest inventories of carbon stocks, to local implementa- tion and measuring carbon loss from forest degradation. Community-based forest monitoring can help overcome some of these challenges. We show that local people can collect forest condition data of comparable quality to trained scientists, at half the cost. We draw on our experience to propose how and where local REDD+ monitoring can be established. Empowering communities to own and monitor carbon stocks could provide a rapid and cost-effective way of absorbing carbon dioxide emissions, while potentially contributing to local livelihoods and forest biodiversity conservation.
Carbon stocks for different land cover types in Mainland Tanzania
Malimbwi, Rogers; Zahabu, Eliakimu; Njana, Marco Andrew; Mugasha, Wilson Ancelm; Mauya, Ernest William
Carbon stocks for different land cover types in Mainland Tanzania
(2019-04) Malimbwi, Rogers; Zahabu, Eliakimu; Njana, Marco Andrew; Mugasha, Wilson Ancelm; Mauya, Ernest William
Background: Developing countries participating in the mitigation mechanism of reducing emissions from defor- estation and forest degradation (REDD+), are required to establish a forest reference emission level (FREL), if they wish to seek financial support to reduce carbon emissions from deforestation and forest degradation. However, establish- ment of FREL relies heavily on the accurate estimates of carbon stock as one of the input variable for computation of the emission factors (EFs). The product of an EF and activity data, such as the area of deforestation, results in the total emissions needed for establishment of FREL. This study presents the carbon stock estimates for different land cover classes based on an analysis of Tanzania’s national forest inventory data generated through the National Forest Resources Monitoring and Assessment (NAFORMA). Results: Carbon stocks were estimated in three carbon pools, namely aboveground, belowground, and deadwood for each of the three land cover classes (i.e. Forest, non-forest, and wetland). The weighted average carbon stock was 33.35 t C ha −1 for forest land, 4.28 t ha −1 for wetland and 5.81 t ha −1 for non-forest land. The uncertainty values were 0.9% for forest land, 11.3% for wetland and 1.8% for non-forest land. Average carbon stocks for land cover sub-classes, which make up the above mentioned major land cover classes, are also presented in our study. Conclusions: The values presented in this paper correspond to IPCC tier 3 and can be used for carbon estimation at the national scale for the respective major primary vegetation type for various purposes including REDD+. However, if local based estimates values are needed, the use of auxiliary data to enhance the precision of the area of interest is recommended. Keywords: Carbon stock, REDD+, FREL, Emission factor, Uncertainty
Charcoal Potential of Miombo Woodlands at Kitulangalo, Tanzania
Malimbwi, R. E.; Zahabu, Eliakimu; Monela, G. C.; Misana, Salome B.; Jambiya, George C.; Mchome, B.
Deforestation and connectivity among protected areas of Tanzania
(MDPI) Gizachew, Belachew; Rizzi, Jonathan; Shirima, Deo D; Zahabu, Eliakimu
Deforestation and connectivity among protected areas of Tanzania
(MDPI, 2020-02-04) Gizachew, Belachew; Rizzi, Jonathan; Shirima, Deo D; Zahabu, Eliakimu
Protected Areas (PAs) in Tanzania had been established originally for the goal of habitat, landscape and biodiversity conservation. However, human activities such as agricultural expansion and wood harvesting pose challenges to the conservation objectives. We monitored a decade of deforestation within 708 PAs and their unprotected buffer areas, analyzed deforestation by PA management regimes, and assessed connectivity among PAs. Data came from a Landsat based wall-to-wall forest to non-forest change map for the period 2002–2013, developed for the definition of Tanzania’s National Forest Reference Emissions Level (FREL). Deforestation data were extracted in a series of concentric bands that allow pairwise comparison and correlation analysis between the inside of PAs and the external buffer areas. Half of the PAs exhibit either no deforestation or significantly less deforestation than the unprotected buffer areas. A small proportion (10%; n = 71) are responsible for more than 90% of the total deforestation; but these few PAs represent more than 75% of the total area under protection. While about half of the PAs are connected to one or more other PAs, the remaining half, most of which are Forest Reserves, are isolated. Furthermore, deforestation inside isolated PAs is significantly correlated with deforestation in the unprotected buffer areas, suggesting pressure from land use outside PAs. Management regimes varied in reducing deforestation inside PA territories, but differences in protection status within a management regime are also large. Deforestation as percentages of land area and forested areas of PAs was largest for Forest Reserves and Game Controlled areas, while most National Parks, Nature Reserves and Forest Plantations generally retained large proportions of their forest cover. Areas of immediate management concern include the few PAs with a disproportionately large contribution to the total deforestation, and the sizeable number of PAs being isolated. Future protection should account for landscapes outside protected areas, engage local communities and establish new PAs or corridors such as village-managed forest areas.
Effect of spacing regimes on growth, yield, and wood properties of tectona grandis at Longuza forest plantation, Tanzania
(International Journal of Forestry Research) Zahabu, Eliakimu; Raphael, Tumaini; Chamshama, Shabani Athumani Omari; Iddi, Said; Malimbwi, Rogers Ernest
Effect of spacing regimes on growth, yield, and wood properties of tectona grandis at Longuza forest plantation, Tanzania
(International Journal of Forestry Research, 2015) Zahabu, Eliakimu; Raphael, Tumaini; Chamshama, Shabani Athumani Omari; Iddi, Said; Malimbwi, Rogers Ernest
This study examined the effects of planting spacing on growth, yield, and wood properties of teak planted at square spacing regimes of 2 m, 3 m, and 4 m at Longuza Forest Plantation, Tanzania. To achieve this, tree, stand, and wood properties were studied at age of 14 years. Results showed that diameter at breast height and total height increased with increasing spacing. Mean annual increment increased significantly with increasing spacing while spacing did not have significant effect on total volume production and basal area. Basic density is also not affected by spacing while heartwood proportion increases as planting spacing increases. All studied wood properties (modulus of rupture, modulus of elasticity, compression strength tangential to grain, and shear tangential to the grain) except cleavage tangential to grain were not significantly affected by increasing spacing. It is recommended to use the spacing of 3 × 3 m, but if thinning can be done before onset of competition at 5 years, the currently used spacing of 2.5 × 2.5 m can still be used. However, the use of a spacing of 4 × 4 m can give at least 50% heartwood at shorter rotation age of 30 years.
Forestland tenure systems in Tanzania: an overview of policy changes in relation to forest management
(INA fagrapport) Zahabu, Eliakimu; Eid, Tron; Kajembe, George; Mbwambo, Lawrence; Mongo, Cellina; Sangeda, Anthony; Malimbwi, Rogers; Katani, Josiah; Kashaigili, Japhet; Luoga, Emmanuel
Forestland tenure systems in Tanzania: an overview of policy changes in relation to forest management
(Department of Ecology and Natural Resource Management Norwegian University of Life Sciences) Zahabu, Eliakimu; Eid, Tron; Kajembe, George; Mbwambo, L.; Mongo, Cellina; Sangeda, Anthony; Malimbwi, Rogers; Katan, Josiah; Kashaigili, Japhet; Luoga, Emmanuel
Forestland tenure systems in Tanzania: an overview of policy changes in relation to forest management
(Department of Ecology and Natural Resource Management Norwegian University of Life Sciences, 2009) Zahabu, Eliakimu; Eid, Tron; Kajembe, George; Mbwambo, L.; Mongo, Cellina; Sangeda, Anthony; Malimbwi, Rogers; Katan, Josiah; Kashaigili, Japhet; Luoga, Emmanuel
ummary Zahabu, E., Eid, T., Kajembe, G. C., Mbwambo, L., Mongo, C., Sangeda, A.Z., Malimbwi, R. E., Katani, J.Z., Kashaigili, J.J. and Luoga, E.J. 2009. Forestland tenure systems in Tanzania: an overview of policy changes in relation to forest management [Eiendomsforholdene for skogarealer i Tanzania: en oversikt over policyendringer i skogforvaltningen]. INA-fagrapport no. 14, 24 pp. A review of the role of forestland tenure systems in Tanzania, and how different forestland tenure approaches and reforms have influenced forest management is presented. The complexity of land reforms and processes that have taken place in Tanzania during the pre-colonial, colonial and post-independence periods is discussed. The pre-colonial period, though not much is written, was characterised by forest management through traditional institutions, low population and low forest resources exploitation. Colonial governments undermined the role of local traditions in managing the forests related to for example burial areas and springs. They also established forest reserves and in some areas cleared indigenous forests to establish tea, coffee and exotic fruit and timber plantations. Different land reforms that were geared towards sustainable development occurred after independence, forests depletion continued, however. Currently, it is observed that there coexists state, village, private and collective rights on forests without clear ownership. This is greatly linked to the ongoing deforestation and forest degradation in the country. In this situation, sustainable forestland use may be attained through establishing an enabling environment that allows effective local communities’ participation in forest management. Sustainable management, however, always presupposes effective control of harvesting and other activities to secure the carrying capacity of forests and woodlands, whether it is undertaken by central authorities or local people. Studies on forestland tenures and rights, and the impact of changes in tenures and rights on forest resources and rural livelihoods are therefore important. Such studies are required for the provision of facts for the establishment of proper future policy means that aim at reducing forest degradation and improving livelihoods in Tanzania.
Impact of Charcoal Extraction to the Forest Resources of Tanzania: The Case of Kitulangalo Area, Tanzania
Malimbwi, R. E.; Misana, Salome B.; Monela, G. C.; Jambiya, George C.; Zahabu, Eliakimu
Mapping and estimating the total living biomass and carbon in low‐biomass woodlands using landsat 8 CDR data
(CrossMark) Gizachew, Belachew; Solberg, Svein; Næsset, Erik; Gobakken, Terje; Bollandsås, Ole Martin; Breidenbach, Johannes; Zahabu, Eliakimu; Mauya, Ernest William