Learn by doing: Modelling the effect of training and job interruptions on tree cutting time for chainsaw operators in plantation forests, Tanzania

Timber harvesting in Tanzania uses semi-mechanized and labour – intensive logging systems. Manual or semi-mechanized logging operations by using hand tools are more favoured due to cheap labour availability. For example, tree cutting is done manually using two-man crosscut saws, axes or chainsaws. This study was conducted at Sokoine University of Agriculture Training Forest to assess the effect of training and job interruptions for chainsaw operators during tree cutting operations in softwood plantation forests in Tanzania. Tree cutting operations using experienced and inexperienced chainsaw operators were studied in three experiments; before training, after training and after the break. Time study and work sampling techniques were used for data collection. Descriptive statistics and modeling was performed for each crews’ performance. Results show that generally, experienced crew spends lesser time in cutting as compared to inexperienced crews. However, start up chainsaw crew spent 32% higher time for preparation before tree felling. However, the crew showed significant improvement after training unlike the experienced one. The analysis of the delay times start up crew was had a significant proportion of the delay times during the first engagement which decreased substantially in the other two experiments. Generally, there was an improvement of the cutting time after training for all crew categories with decrease after the break. This observation signifies that job interruptions impact the productivity of the crews. Therefore, on job training on resumption of the operations may significantly improve crews’ productivity, safety as well as ensuring product quality. Key words: Tree cutting, training, chainsaws, time studies, Tanzania

Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests

For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relatively crude estimates of average values per continent and ecological zone. The 2006 default values were based on limited plot data available at the time, methods for their derivation were not fully clear, and no distinction between successional stages was made. As part of the 2019 Refinement to the 2006 IPCC Guidelines for GHG Inventories, we updated the default AGB values for tropical and subtropical forests based on AGB data from >25 000 plots in natural forests and a global AGB map where no plot data were available. We calculated refined AGB default values per continent, ecological zone, and successional stage, and provided a measure of uncertainty. AGB in tropical and subtropical forests varies by an order of magnitude across continents, ecological zones, and successional stage. Our refined default values generally reflect the climatic gradients in the tropics, with more AGB in wetter areas. AGB is generally higher in old-growth than in secondary forests, and higher in older secondary (regrowth >20 years old and degraded/logged forests) than in young secondary forests (20 years old). While refined default values for tropical old-growth forest are largely similar to the previous 2006 default values, the new default values are 4.0-7.7-fold lower for young secondary forests. Thus, the refined values will strongly alter estimated carbon stocks and fluxes, and emphasize the critical importance of old-growth forest conservation. We provide a reproducible approach to facilitate future refinements and encourage targeted efforts to establish permanent plots in areas with data gaps

The Cost of Managing Forest Carbon under REDD+ Initiatives: A case of Kolo Hills Forest in Kondoa District Dodoma, Tanzania.

Countries considering participating in a REDD+ mechanism need information on what it would cost them to reduce emissions fromdeforestation and forest degradation. This study was conducted to estimate the cost ofmanaging forest carbon under REDD+ initiatives in Kolo Hills Forest, Kondoa, Tanzania. Socioeconomic and biophysical information was collected through structured questionnaires, focus group discussions, and forest inventory, respectively. Results show that the community participated in managing the forest by undertaking a range of activities such as tree planting, patrolling, and fire protection.The estimated total cost was USD 418,349.38 while the average cost was USD 79.06/ha.The average carbon stored was 19.75 tC ha−1, which is equivalent to 72.48 tCO2 ha−1. Costs incurred by managing the forest in relation to tCO2 stored were USD 1.0485 tCO2 e−1ha−1. The project was found to be economically feasible at 5%, 10%, 15%, and 20% discount rates withNPVs ofUSD107,102,331.83,USD33,986,255.86, USD 10,312,945, and USD 1,245,905.11, respectively. The internal rate of return was 21.21% which is much higher than the World Bank rate of 15.8% and the Tanzania rate of 14.8%. We therefore conclude that the decision to undertake this REDD+ project was worthwhile and should be favoured against the “do nothing” alternative

Productivity and costs modeling for tree harvesting operations using chainsaws in plantation forests, Tanzania

This article is available at http://dx.doi.org/10.14419/ijet.v3i4.3407With exemption of a few private forests, timber harvesting in most plantation forests in Tanzania is carried out by less skilled and less equipped crews. Newly recruited crews often learn from experienced ones which may not be doing it in the perfect way. Therefore estimation and projecting production and costs becomes a big problem to logging managers. This study was carried out to develop productivity and costs models for chainsaw operators in a learning experiment. The experiments were designed in clear felling operations. Three experiments were set where each crew category was studied using time study and work sampling techniques that involved studying crews before training, after training and after the break at an interval of three months. Descriptive statistics and modelling was performed for each crews’ performance. Specific crew’s productivity and costs models have been developed reflecting necessary and unnecessary delay times. Assessment of the production costs show that unit costs decreases with increasing productivity in each unit of measurement of the production rate. It is recommended that productivity and costs for two-man crosscut saw operators be studied and modelled since they are also the main cutting tools used in tree cutting in Tanzania

REDD+ piloting process in the Zanzibar Islands, Tanzania: The assessment of the community perceptions and attitudes

This article is available at http://dx.doi.org/10.4314/ejesm.v7i5.8Introduction of REDD+ initiatives in Tanzania underwent a series of preparation activities including launching and implementation the National REDD+ pilot projects. While the piloting have now lasted for four years the local communities awareness, perceptions and their attitudes towards these initiatives have not been adequately studied in Tanzania. This study therefore was carried out to assess the community perception and determine social sustainability of REDD+ initiatives in anzibar Islands. Specifically the study aims to determine the levels of community awareness, perception, participation and attitudes towards this initiative. Five Shehia (Villages) which are Kumbaurembo, Muyuni C, Mtende, Chuchumile and Hanyegwamchana were involved in the study. Data were collected through key informant interviews, focus group discussions and household questionnaire survey. Content analysis was used to analyse qualitative information from focus group discussions and in depth interviews, while indexes were used to determine the levels of community participation, awareness and attitudes. Findings revealed a high level of community awareness (63.3%) with moderately high level of participation as shown by 4 .8%. Results show a favourable attitude of about % despite the low levels of education, over dependence of forest resources and small size of land holdings that would be expected to affect communities perception, attitudes. The study concludes that communities in anzibar islands have positive attitude and perceptions on conservation initieatives which is a good indicator for sustainability of REDD+ initiatives. However, in a bid to sustain the communities continued involvement, there should be continued capacitation of the communities to be in full control of their resources as well as ensuring equitable benefit sharing.Norwegian Government through NORAD to the Climate Change Impacts Adaptation and Mitigation (CCIAM) Programme at Sokoine University of Agriculture (SUA), Tanzania

What does it take to institute REDD +? An analysis of the Kilosa REDD + pilot, Tanzania

Reduced emissions from deforestation and forest degradation (REDD +) has been seen as an important element in future climate policies. This paper analyzes the establishment of a REDD + pilot project in Kilosa district, Tanzania. It documents changes in organizations and institutions for land management undertaken to enable villagers to produce and sell stored carbon. Moreover, it evaluates the legitimacy both of the process of introducing REDD + and the outcomes in the form of new governance structures. We find that establishing tradable carbon is demanding. In fact, no carbon has yet been sold. We observe that while the Kilosa REDD + pilot managed to engage local communities to a rather unusual extent, the case also showed that introducing REDD + ‘on the ground’ faces several challenges regarding legitimacy.What does it take to institute REDD +? An analysis of the Kilosa REDD + pilot, TanzaniaacceptedVersio

Working Conditions and Productivity Under Private and Public Logging Companies in Tanzania

Industrial timber harvesting in plantation forests in Tanzania was solely performed by public agencies until mid 1980’s. During that period harvesting operations were labour-intensive and semi-mechanized, coupled with low production rates and high production costs. Following the privatization of forestry industries, logging is currently being carried out by private companies. This study was carried out to assess and compare working conditions, physical workload and productivity in logging operations under private and public logging regimes. Data were collected in Sao Hill Forest plantations from a clear felling operation being carried out in a 26 years old Pinus patula stand. Time study was undertaken for tree cutting, skidding, manual bunching and loading operations. Physical workload data were obtained through heart rate measurement by using portable electronic heart rate monitor. Working conditions were assessed through ergonomic checklist administered to 45 loggers. The results indicated that the productivity in tree cutting averaged 4.7m3/h and 3.4m3/h for chainsaw and crosscut operations respectively, while in bunching and loading the respective values of 5.1m3/h and 11.3m3/h made higher production on the private regime as compared to the public. The working conditions were generally poor with low safety, inadequate payment and poor working tools coupled with high labour turnover. The physical workload was 78% and 65% heart rate increase for crosscut saw and chainsaw crews. This is a slight increase compared to the public logging regime estimated at 65% and 57% increase for crosscut saw and chainsaw respectively. However, the increased productivity observed in the private regime was not due to improved working conditions, but rather a result of the workers’ higher engagement and placed effort in performing production tasks. Training of the crews, improvement of payments, supervision and provision of safety gears are recommended for improved production and reduced occupational health hazards