Browsing by Author "Mugasha, Wilson Ancelm"

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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.
Biomass and volume models based on stump diameter for assessing degradation of Miombo woodlands in Tanzania
(Hindawi) Manyanda, Bernardol John; Mugasha, Wilson Ancelm; Nzunda, Emannuel F; Malimbwi, Rogers Ernest
Biomass and volume models based on stump diameter for assessing degradation of Miombo woodlands in Tanzania
(Hindawi, 2019) Manyanda, Bernardol John; Mugasha, Wilson Ancelm; Nzunda, Emannuel F; Malimbwi, Rogers Ernest
Models to estimate forest degradation in terms of removed volume and biomass from the extraction of wood fuel and logging using stump diameter (SD) are lacking. The common method of estimating removals is through estimating diameter at breast height (D) by applying equations relating measured D and SD. The estimated D is then used to estimate biomass and volume by means of allometric equations, which utilize D. Through this sequence of procedures, it is apparent that there is an accumulation of errors. This study developed equations for estimating volume, aboveground biomass (ABG), and belowground biomass (BGB) using SD in miombo woodlands of mainland Tanzania. Volume models were developed from 114 sample trees while AGB and BGB models were developed from 127 and 57 sample trees, respectively. Both site specific and regional models were developed. Over 70% of the variations in BGB, AGB, and volume were explained by SD. It was apparent that SD is inferior compared to measured D in explaining variation in volume and BGB but not AGB. However, the accuracy of BGB and volume estimates emanating directly from SD were far better than those obtained indirectly, i.e., volume or BGB estimates obtained from estimated D from SD, since the latter is affected by accumulation of regression equation errors. For improved accuracy of ABG, BGB, and volume estimates, we recommend the use of site specific models. However, for areas with no site specific models, application of regional models is recommended. The developed models will facilitate the addition of forest degradation as a REDD+ activity into the forthcoming FREL.
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
Drivers and their influences on variation of aboveground carbon removals in miombo woodlands of mainland Tanzania
(BMC [Commercial Publisher]) Manyanda, Bernardol John; Nzunda, Emmanuel Fred; Mugasha, Wilson Ancelm; Malimbwi, Rogers Ernest
Effects of drivers and their variations on the number of stems and aboveground carbon removals in miombo woodlands of mainland Tanzania
(BMC) Manyanda, Bernardol John; Nzunda, Emmanuel F; Mugasha, Wilson Ancelm; Malimbwi, Rogers Ernest
Estimates of volume and carbon stock removals in miombo Woodlands of mainland Tanzania
Manyanda, Bernardol John; Nzunda, Emmanuel F; Mugasha, Wilson Ancelm; Malimbwi, Rogers Ernest
Stump height: a potential escalator of wood volume and carbon removals in miombo woodlands of mainland Tanzania
(Springer) Manyanda, Bernardol John; Malimbwi, Rogers Ernest; Mugasha, Wilson Ancelm; Nzunda, Emmanuel F.
Stump height: a potential escalator of wood volume and carbon removals in miombo woodlands of mainland Tanzania
(Springer, 2022-04) Manyanda, Bernardol John; Malimbwi, Rogers Ernest; Mugasha, Wilson Ancelm; Nzunda, Emmanuel F.
Mitigation and adaptation to climate change in developing countries require sustainable forest management through either retaining the forest unharvested, i.e., conservation or an increased need for proper tree harvesting. However, significant number of trees harvested in miombo woodland of mainland Tanzania are not cut at the specified stump height, i.e., 15 cm from the ground. Leaving extra stump height (ESH) would escalate wood vol- ume removals and hence carbon emissions. Better insights on the extent of wood volume and carbon emissions of ESH in miombo woodlands are apparently needed. This study intended to estimate volume and carbon of ESH in miombo woodland of mainland Tan- zania. Based on a sample of 5 264 stumps collected in miombo woodlands of Mainland Tanzania, total annual volume and annual carbon per hectare of ESH were estimated by using equation applicable to cylinder in R software. Result revealed that total annual vol- ume, annual volume and carbon per hectare lost through ESH were 3 800 000 m −3 year −1 , 0.098 ± 0.034m 3 ha −1 year −1 and 0.028 ± 0.009 tCha −1 year −1 , respectively. The volume and carbon loss from ESH per hectare per year escalate 6% and 5% of more volume and car- bon removals, respectively, in the entire miombo woodlands and its categories in mainland Tanzania. Since annual volume loss of ESH is almost 1⁄4 of annual volume deficit of 19.5 million m 3 year −1 , the deficit and further removals could be lowered through adhering to appropriate harvesting regulations.