School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemNitrogen fixation by Casuarina oligodon agroforestry in the Papua New Guinea central highlands( 2006)Casuarina oligodon L. Johnson is a multipurpose tree species grown in the highlands of Papua New Guinea (PNG). The integration of C. oligodon into agricultural systems is seen by villagers as means of restoring soil fertility, controlling soil erosion, providing shade for crops and producing fuel wood and building materials. Biological nitrogen fixation by C. oligodon through symbiotic relationships with Frankia (micro-organism) under field conditions in short (5-10 years) and long (11-15 years+) fallows in the PNG central highlands was investigated using the 15N natural abundance technique. Results from the study showed that as much as 70% of N in C. oligodon was derived from the atmosphere. The rate of N2 fixation was relatively low in short fallows of casuarina and increased as the trees aged in the long fallows. A rate of N2 fixation up to a maximum of 36 kg N ha -1 year -1 was estimated based on commonly practiced tree stocking rates and field conditions in the PNG highland areas. Although casuarina fallows tend to accumulate higher total N and C compared with equivalent period of grass fallows, the amounts of N and C in the surface soils of all systems under the study showed no significant difference. The amounts of total N and C under long fallows of casuarina (11-15 years+) were generally greater than short fallows of casuarina (5- 10 years). A significant proportion of the total N was stored in the above ground biomass of trees that were more than 10 years of age. Management of the standing biomass, particularly when the fallow is converted back to the cropping phase, is therefore critical in ensuring that the farmers are able to gain maximum benefit from the fixed N. Whilst the removal of stem wood for use as fuel or building material may be an important product of the agroforestry system, retaining the foliage, small branches and bark on the site is vital in sustaining agricultural productivity.
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ItemPerceptions of ecoforestry in selected project sites in Papua New Guinea( 2005)Land and forest resources in Papua New Guinea are held under customary ownership by clans. But clans have participated little in decision-making processes in any major forest resource development projects, although these have often had major effects on their areas and lives. The decisions about industrial logging have been made mainly by the government and multinational logging companies - though royalties have been paid to clans for extraction of the timber. Past logging operations have provided some infra-structural benefits but have also led to many environmental and socio-economic problems that affect the livelihoods of rural people. In an attempt to halt the further spread of large-scale logging, and under pressure from the World Bank, the European Union Commission to PNG and the Government of Papua New Guinea entered into a bilateral agreement to initiate the Papua New Guinea Ecoforestry Program in 1995. This was to be implemented through the involvement of clans as the forest resource owners. This study explores the experiences and views of clan members in two ecoforestry projects in West New Britain Province. The aims of the study were to describe the ecoforestry program in general and the two project study sites, and then to explore clan members' perceptions of the ecoforestry approach being promoted, based on their experience. The study was conducted with a view to identifying ways of improving the effectiveness of ecoforestry development projects in Papua New Guinea. Two ecoforestry project sites were chosen as case studies. The main data collection techniques were in-depth interviews with clan members participating in the ecoforestry projects, and observations of activities. The qualitative data collected were analysed using elements of a 'grounded theory' approach, which involved transcription of interviews from PNG Pidgin/English to word processed files in English, then examining and coding the transcripts for main themes. From these themes theory was developed about the way clan people viewed ecoforestry, and the prospects for the future of the approach. Data from secondary sources were used in description of the sites, and in the analysis and interpretation of data from interviews. The findings revealed strong views among some respondents about their gains in mechanical and management skills through the ecoforestry projects, and also on problems of transparency in financial management of projects, the hard work involved in ecoforestry, and difficulties faced by their female members left at home alone. Other difficulties mentioned were those of maintaining equipment and of sourcing spares for machines and securing reliable markets. Despite the many negative views expressed on ecoforestry, there was quite wide acceptance that the approach had major potential advantages in terms of self-determination for clans, learning skills, employment and income, village infrastructure and environmental care of the forest - when compared to industrial logging. In the final chapter a Force Field Analysis is used as a framework to discuss the implications of the main finding - for future efforts in ecoforestry in PNG. In general, the clan members were reluctant to give definite views on the future prospects of ecoforestry after withdrawal of the supporting aid agency. In answer to questions on this topic they tended to express views on the need for certain types of support in the future, and other ways for overcoming the difficulties of the past. There was a general desire to be given the opportunity to continue with the ecoforestry approach, in the hope that there would be improvement in community participation, skills and hence in benefits to their clans and communities.
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ItemForest management certification in West New Britain province, Papua New Guinea( 2004)The main objective of this study was to investigate the experiences of the stakeholders who participated or were affected by the `PNG Eco-forestry Program' forest certification scheme. The move to certification as a sustainable forest management alternative was introduced because from 1992 to 1995 the West New Britain Province and Papua New Guinea were under a lot of pressure from unsustainable conventional commercial logging, mainly controlled by large overseas based timber-mafia logging companies. The `PNG Eco-forestry Program' forest certification scheme was established and funded by the European Union under its STABEX FUNDS in 1995 as the Islands Regional and Community Development Program. The Program has achieved some significant outcomes in securing five project areas certified, covering an area of about 8,360 ha, and two newly established Eco-forestry projects one of which are in their final preparation stage for certification. However, to achieve sustainable forest management through certification, the Program is faced with the need for an eco-forestry policy. The application of the `Eleven Steps' approach to achieve sustainable forest management through certification is limited and faced considerable difficulties for seven main reasons: 1) the issue of not being recognized nationally as a management approach to achieve sustainable forest management; 2) the lack of proper research and awareness on current forest policy; 3) the lack of consideration for both markets for sawn timber and non-timber forest products; 4) the use of outdated forest inventory maps and equipment; 5) the lack of funding; 6) the premature relocation of the Program's head office from Kimbe to Lae, and 7) the lack of improvement in market price for sawn timbers. The results from this study suggested that the process of achieving sustainable forest management through certification was flawed for seven main reasons: 1) there were no ecoforestry policies; 2) there were no appropriate forest management standards; 3) the devaluation of the Kina caused a decline in real (free of inflation) market prices for sawn timber; 4) the lack of markets for non-commercial timber species and non-timber forest products; 5) the lack of funding; 6) the lack of participation by resource owners, and 7) the poor landownership determination processes. In addition, the under-resourced Provincial Forest Management Unit was reluctant to provide resource owners with technical and legal advice on current forestry and policy issues. This also negatively impacted the community's participation in the negotiation processes about their forest resources. The Government should change its approach to forest policies to favor of small-scale forestry operations, and improve the current market prices for sawn timber. The local forest owners will then be better able to move towards sustainability by implementing management standards based on ecological sustainability, using an improved system of certification based on the Eleven Steps process and the findings of this study. Recommendations on policy development and research have been provided.
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ItemComparative analyses of genetic diversity, cocoa quality and flavour characteristics in selected Papua New Guinea cocoa genotypes( 2001)This study explored three aspects of cocoa breeding: (1) evaluating the quality characteristic of new breeding lines to select genotypes that have good flavour and quality attributes (2), DNA fingerprinting of selected genotypes to assess genetic diversity of selected breeding lines and (3), evaluating the influence of genotype x environment (GE) interactions on bean quality. The quality of Papua New Guinea (PNG) beans has deteriorated in recent years. Manufacturers are very critical of this situation. In 1999, the International Cocoa and Confectionary Organisation (ICCO) reduced PNG's Fine/Flavour status from 75% to 30%. This has had a negative impact on the industry because PNG's cocoa exports will be subjected to quota restrictions, unlike previously. There is an urgent need to re-establish PNG's Fine/Flavour status and address other quality problems. Flavour and quality related problems are now being addressed through a selective plant breeding programs. Genotypes with high fat content, large bean size, good chocolate and pronounced fruity flavours were selected for this study. These genotypes will be integrated into the breeding programs to replace current genotype, which lacks desirable bean flavours and quality. DNA fingerprinting of the selected genotypes showed high levels of genetic diversity. The genetic dissimilarity between any two genotypes ranged from 14% to 52%, with an average of 29%. A mixed model analysis of variance used to determine the genotype x environment interaction on bean quality showed that fat content, bean count, shell content and recovery rates of the genotypes were significantly influenced by genotype x replicate interaction. The month x genotype interaction also influenced fat content; shell content and bean count were significantly influenced by the plant size. Pearson correlation was used to evaluate correlations between each of the bean quality parameters, and showed that there was a significant correlation only between fat content and recovery rate.
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ItemImproved logging and portable sawmilling practices in Papua New Guinea( 2004)The management of the natural forest in Papua New Guinea has been a concern locally, nationally and internationally due to poor logging practices in the past three decades. The method of logging adopted is selective logging using conventional logging systems. Forestry as a renewable resource is a source of food, materials, fuel wood, and income for local people and is the third largest revenue source for the country. Therefore better logging practices using reduced impact logging system may be a better way to manage the natural forest sustainably with reduced cost and damage to the environment. This study investigates whether: • Reduced impact logging is better or worse than conventional logging; and • Reduced impact felling and processing is better or worse than conventional felling and processing in portable sawmilling. The data for the research comes from two different natural forest harvesting studies. Firstly, logging operations were studied using two sets of data. The first set was from a 100-hectare plot and the second from four one-hectare plots were qualitatively and quantitatively analyzed. The second source of data was from the portable sawmills that were basically owned by local resource owners. Comparisons were made on conventional and reduced impact techniques applied to both the logging and the portable sawmill operations. The variables tested were merchantable trees harvested, harvesting waste, skid tracks, damages to residual trees, damages to potential crop trees, tree species lost, forest canopy gap size, regeneration, sawn timber recovery rate and harvesting cost. Results reveal significant differences between conventional and reduced impact techniques applied in logging operations and also in portable sawmill operations. In the 100 hectare logging operations, reduced impact logging has reduced the number of trees harvested from 19 to 11 trees per ha, wood waste from 6.4 to 1.7 cubic metres per ha, distance of skid tracks from 296 to 172 metres per ha, width of skid track from 5.4 to 4.3 metres, residual trees damaged from 43 to 21 percent, number of potential trees damaged from 29 to 11 trees per ha, the sizes of canopy gap from 50.1 to 17.9 percent, number of species lost from 10 to 3 species per ha and harvesting cost from K651 to K517 per ha. In addition, similar results were found in the four one-hectare plots. However, diameter increment of residuals and regeneration after logging was greater in conventional logging than reduced impact logging. In the portable sawmill operations reduced impact felling and processing reduced harvesting (wood) waste from 28 to 2 cubic metres per ha, residual trees damaged from 33 to 15 percent, number of potential crop trees damaged from 7 to 4 trees per ha, canopy gap size from 30 percent to 10 percent and number of species lost from 12 to 2 species per hectare. In addition, reduced impact logging improved sawn timber recovery rate from 27 to 47 percent. Harvesting cost in reduced impact felling and processing was increased by K21 per hectare, however, statistical test shows no significant difference between conventional and reduced impact felling and processing systems. The thesis concludes that: • Reduced impact logging system is better than conventional logging system; and • Reduced impact felling and processing is better than conventional felling and processing in portable sawmilling.