Theses and Dissertations Collection

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Productivity and physical workload of cutting crews in sao hill softwood plantations
(Sokoine University of Agriculture, 1996) Malisa,Emilson Jeremiah
Physical workload and cutting of productivity two-man raker and peg toothed saws were compared when clearfelling a Pinus elliottii compartment in Sao Hill forest plantation. Three logging crews working with the two types of saw were studied between July and October 1990. Heart rate data was collected after every 30 seconds using a SPORT TESTER while maximum aerobic power was estimated using sub-maximal tests on a cycle ergometer respectively. A total of 1271 trees with an average Dbh of 25 cm were felled and bucked into logs. Analysis of the data revealed that: (a) Effective cutting time when using raker and peg toothed saws were 8.8 and 9.6 min/tree respectively. For a 7 hour workday only about 4.7 hours were spent for productive work. (b) Raker-toothed saws had higher rates than peg-toothed saws. cutting production Production rates raker and peg- toothed saws ranged from 3.25 for 3.6 and 2.98 - 3.16 m3/crew - h respectively. (c) The heart rates of the workers during effective cutting time were 112 - 117 and 115 - 118 beats/minIll when using raker and peg-toothed saws respectively. Maximum aerobic power of the workers averaged 2.54 1/min ranging from 2.37 to 2.74 1/min. (d) Oxygen consumption rate was on the average 1.23 1/min ranging from 1.11 1.30 1/min when using raker- toothed saws. The demand averaged 1.28 1/min with peg-toothed saws ranging from 1.14 - 1.38 1/min. Thus energy demand when using peg-toothed saws was about 28% higher than for raker-toothed saw cutting. This indicated that raker- toothed saws could be a better choice for cutting operation. (e) Physical workload on the workers when cutting using the two types differences. of saws showed no significant The workload indices during effective cutting time using raker and peg-toothed saws were 43.7 52.6 % and 44.8 53.6% respectively. This showed that the cutting operation was a moderate energy demanding job.
The role of local knowledge and organizations in sustainable conservation of biodiversity: a case study of Udzungwa mountains, Tanzania
(Sokoine University of Agriculture, 2000) Mbwambo, Jonathan Stephen
To some extent the conservation of biodiversity in Tanzania is currently vested on local communities. This strategy is clearly stipulated in the National Forest Policy of 1998. The success of this strategy depends largely on people's local knowledge, organizations and their underlying institutions. Local knowledge and organizations constitute essential component for attempts to facilitate local level engagement in conservation and utilization of natural resources. However local knowledge and organizations were neglected in the past until recently when their importance have been stressed in rural development and conservation of natural resources in particular. This study was conducted to identify different local knowledge systems, organizations and their underlying institutions in the management and conservation of Udzungwa Mountains National Park. Specifically the study sought to: assess changes occurred in the forest resource base over time, identify and assess the role of the existing local organizations (both internally and externally sponsored) and their underlying institutions in biodiversity conservation and to assess the state of conflict between externally and internally initiated organizations. Other specific objectives include identification of indigenous practices and their role in the conservation of biodiversity in Udzungwa Mountains National Park, identification of socio-economic factors including gender, which enable or constrain local people participation in biodiversity conservation and propose a model that will ensure sustainable conservation of biodiversity for Udzungwa Mountains National Park. The study was carried under two phases. Phase one of the study involved Participatory Rural Appraisal techniques in two villages namely Msolwa and Sonjo. Participatory Rural Appraisal techniques were designed to quickly generate information about local conditions, livelihood and social formation around Udzungwa Mountains National Park. The second phase involved structured questionnaire surveys as the major tool for data collection. Questionnaire survey was done in four villages namely Msolwa, Sonjo, Ichonde and Kisawasawa. The sample size in each village was 5 percent of the total number of households. Other tools used were checklist and participant observation. Data collected by using Participatory Rural Appraisal techniques in phase one were analyzed with the help of the communities and the results were communicated back to them. The Statistical Package for Social Science was used to analyze quantitative data whereas Content and Structural-Functional Analysis were used for qualitative data. The study revealed the presence of various internally initiated organizations. These include village governments, village Community Conservation Committees, fire brigades, women groups, religious organizations, primary schools and cooperative unions. Ranking of these organizations by farmers indicated that village government, village Community Conservation Committee, fire brigades are more effective in decision making in joint management of natural resources in Udzungwa Mountains National Park. About 49 percent of respondents described the role of these organizations as being both tree planting and enforcement of rules and regulations. The study also identified two externally sponsored organizations, namely World Wildlife Fund and Tanzania National Parks. More than 85 percent of the respondents said that there is no conflict between externally and internally sponsored organizations. Similarly more than 75 percent of the respondents participate in tree planting and that both men and women participate^ equally in tree planting. Pollarding, pruning and the use of ash against termites are some of the indigenous management practices pointed out by most respondents. The presence of traditional institutions such as Bokela, traditional healing and sacred groves in the Udzungwa Mountains National Park is the evidence that the resource base has been protected and conserved by the local people even before the advent of externally sponsored institutions. The study concludes by saying that local people could work and provide the means for sustainable management and conservation of Udzungwa Mountains National Park. The study recommends strengthening the present agroforestry program through joint ownership of tree nurseries, formation of agroforestry demonstration plots and more emphasis should be put on education and extension. The study also recommends carrying out inventory and identification of traditional medicines to ascertain their distribution for effective conservation. Carrying out effective ecological monitoring and evaluation are other recommendations of the study.
Factors affecting the consumption of working time and the strain on the worker in some
(Sokoine University of Agriculture, 1975) Harstela, Pertti
The purpose of the study was to formulate an ergonomic model for forest work to serve as frame of reference for theoretical and empirical analysis, to examine the correlations of independent variables in play in forest work such as human, conditions and working method variables with consumption of working time and the physical strain on the worker. The investigation was confined in the empirical material to the cutting of roll-seedlings and the lifting of seedlings in the nursery-, and to the cutting of pulpwood by two working methods, i.e. mediumheavy and heavy work. The final aim was to formulate and test hypotheses of forest work science, postulate new hypotheses and outline an overall theory on the basis of systems analysis. An additional special object was to study the application of the principle of comparative time study in an empirical material and to apply the same principle in pulse rate investigations. This is termed the principle of comparative work study. The work performance was illustrated by a system scheme (Fig. 1). The scheme comprised the following main groups of elements: worker’s inclination for work, working capacity, reflexes and instincts, decision process, environmental factors, working methods and habits, work performance, output, earnings, and effects on the worker. The model was made up parallclly from abstract and concrete concepts, the aim being to make it suitable for the set of concepts of the theory of work study and the level of theory formulation. The model included the feedback from the effects on the worker-sample element group to the worker’s qualities. The literature on forest work studies in which some correlations introduced in the model were investigated is reviewed in Chapter 23. Owing to the great number of output studies they were treated as an example. The greatest part of the research activity has been analysis of the relations between environmental factors — and of them primarily the work difficulty factors — and the work output. The previously outlined system formula is examined in Chapter 24 as a cybernetic, probabilistic system in which the elements as such were conceived to embrace complex linkages and to be of the black-box type. The information transfer of these sample elements was illustrated by only one channel and information was consequently analysed merely as a symbolical expression of space and event. The decision process and the effects of reflexes and instincts were examined as the self-regulatory mechanism of the model. Feedbacks were established both within the worker and between the worker and environment. Principles influencing the formulation of the theory' of work science were postulated on the basis of the general properties of the system, such as threshold values, correlations, the principles of isomorphism and homomorphism: — If a correlation proves to be significant it is relevant at least in the population represented by the material and possibly also in other populations. — On the other hand, if no significant correlation is established between some independent variables there may nevertheless be a significant correlation in some other population or after some threshold values. — Il is useful for development of the theory' to explain the trend of the correlations and the internal conformities to law and mechanism of the elements. — It is assumed hypothetically that the constancy of the relative per-worker working time and strain value is influenced by the difference between the worker’s capabilities that the working methods and working conditions require and by his attitude to the working methods under comparison and his experience. — model taken from nature through simplifications is the more servicable the more deterministic it is. — Empirical work study generally' observes coded messages by indirect means and it is therefore seldom possible to demonstrate direct physiological causal relationships; what results is explanations of the ”either-or” or ”both-and” type. The system description of the work was developed in Chapter 25 by hypothetical insertion in the model of elements formed by the set of concepts of work study principles (Fig. 2). The concepts are: speed of work, physical strain, ratio between physical strain and maximal performance, total strain during the working day, psychic strain, relative consumption of time, average consumption of time, deviation of consumption of time, average strain, deviation of strain, relative strain, and attitudes to work. The quantitative and abstract levels of the concepts of the model were studied using the M-67-meta theory. Fig. 3 shows the concept hierarchies and the measuring features of the concepts. In processing the measuring features for formulation of the theory in the empirical part, concepts of the same quantitativencss arc used which are sub-concepts of the high real theoretical concepts: the worker’s capacity' and inclination for work, effects on the worker, performance, output and environmental factors. Fig. 4 shows the processes as a being model: performance — output and performance — effects on the worker, the worker’s resources (capacity for work) and feelings (inclination for work) and working conditions (environment) which influence the interrelations of these processes. The Jiving organism state of equilibrium. It logical theories that if a was found to be a system which seeks to preserve a was assumed from reference to physiological and psychofactor causes a greater deviation in the equilibrium of the organism than the conditions of other factors, that factor dominates the behaviour of the organism. This theory was applied in the empirical part to explain the phenomena established. In the empirical part the effect was examined of different factors on the consumption of working time, the physical strain on the worker, and the application of certain work study principles in the nursery to the cutting of roJlseedlings, the lifting of pine seedlings and the logging of pulpwood in grapple piles alongside the strip road (working method 2) and a 4-m wide zone for which the bunch size required was reduced (working method 1). The material and the measurements made are described in Chapter 32. The most important results were as follows. Owing to the paucity of degrees of freedom which interfered with testing they were distributed into statistically significant correlations and hypothetical correlations: — Consumption of working time was explained significantly in regression analysis by so-called work difficulty factors, working method, moving speed which illustrates the speed of the work, the time of the working day, the ordinal number of the working day and some independent variables that portray the worker.
Bark-stripping and food habits of blue monkeys in a forest plantation in mount Meru, Tanzania
(UNIVERSITY OF IDAHO, 1989-04) Maganga, S. L. S
Bark-stripping of Cupressus lusitanica (cypress) and Pinus patula (pine) by blue monkeys (Cercopethicus mitis kibonotensis) in Meru Forest Plantations has been a problem since they were established in the early 1950s. This study was conducted in 1987 in the Sokoine University of Agriculture determine the magnitude of bark-stripping in relation to the food habits of blue monkeys. assessed in compartments with trees 3 to 14 years old, and the pattern of debarking was monitored throughout the year. On the average, 79.5 % cypress and 88.7% pine trees were debarked. Blue monkeys preferred dominant cypress trees to intermediate trees. In contrast, intermediate pine trees were more damaged than dominant trees. In both species, suppressed trees were least damaged. In all types of trees, the most severe bark damage occurred at the middle and top of the tree trunks. Twisted bole was the most common defect developed by damaged trees; 34% cypress and 38% pine trees were twisted at the middle and top sections. Bark-stripping was low in the rain season and increased in the dry season peaking at 22% of trees damaged in June and July. ■ The food habits data were collected from the indigenous forest at two sites within the plantation. A total of 38 plant species were eaten by blue monkeys. Fruits were the Training Forest, a portion of the Meru Forest Plantations, to The extent, intensity and effects of bark damage were Bark-stripping of Cupressus lusitanica (cypress) and iv most frequently consumed food item and averaged 76% of the monthly feeding records. Leaves were the next important food item but they were inversely related to the feeding on fruits. The other food items (flowers, shoots, petioles and bark) were similarly inversely related to the feeding on fruits. Bark stripping was negatively correlated to the feeding on fruits, and thus increased when the feeding on fruits declined. Fruits of Ficus thonningii were the prime item in the diet of blue monkeys contributing 50 to 60% of the monthly feeding records. The amount of fruit on these trees in the area was also inversely related to extent of bark damage in the plantation. The water and carbohydrate in the bark of cypress and pine trees was determined to examine if they influenced the bark-stripping. These were poorly correlated to the monthly debarking of both tree species.
Carbon storage potential and climate change mitigation: a case of pugu forest reserve, Kisarawe district, Tanzania
(Sokoine University of Agriculture, 2013) Beda, Goodluck
Pugu Forest Reserve is a coastal forest covering an area of 2,410 hectares; but has been significantly altered by on-going extraction and conversion to other land uses which releasing carbon dioxide into the atmosphere thus making the forest a net emitter of the greenhouse gases. Though some empirical data exist regarding carbon storage in African coastal forests, little has been done to assess and quantify the carbon stocks and emissions associated with deforestation and/or degradation in all coastal forests, Pugu Forest Reserve inclusive. This study estimated carbon storage of Pugu FR to quantify the above ground carbon in the tree component, the understory carbon components and carbon storage in the soil. An inventory was conducted using a 20m x 40 m (0.08 ha) plots. Above ground tree carbon was determined using an allometric model that uses trees DBH ≥ 5 cm as predictor variable. Carbon storage in litter, herbs and dead wood was determined using Loss of Ignition method, while Walkley-Black method was used to analyse soil carbon. The total carbon density for all 5 pools was 30.95 t C ha-1 equivalents to 113.59 t CO2e ha-1. The mean carbon densities for the above ground components was 6.75 t Cha-1 (24.77 t CO2e ha-1) in which the tree component accounted for 4.5 t C ha -1 equivalent to 16.5 t CO2e ha-1 ( 14.5%); understory components of litter accounted for 0.52 t C ha-1 equivalent to 1.9 t CO2e ha-1 (1.7%); dead wood 1.01 t C ha-1 equivalent to 3.7 t CO2e ha-1 (3.3%), herbs 0.72 t C ha-1 equal to 2.6 t CO2e ha-1 (2.3%) and soil organic carbon stock was 24.2 t C ha-1 equivalent to 88.8 t CO2e ha-1 (78.2%). The mean carbon stored in this forest is lower compared to other coastal forests especially in the above ground component indicating an alarming degradation and destruction. Improved management and restoration of degraded parts can greatly increase the C storage potential and emission mitigation by this forest. Using this information as the baseline carbon stocks; can be potential for participation in carbon trading under the current REDD+ initiatives with contribution to alternative livelihoods and sustainable development to adjacent communities.

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