528 research outputs found

    Rationale and key research questions addressed by field trails established as part of the ACIAR Smallholder Tree Farmer Project

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    A series of field trials have been established as part of the ACIAR Smallholder Tree Farmer Project. These trials are designed to have both a research and demonstration function. A field trial was designed to investigate the potential interaction between four species providing a combination of native and exotic species and nitrogen-fixing vs non-nitrogen-fixing. Importantly, this design provides information about different mixture ratios using only one plot. This field trial will provide important information about the interactions of the four species when grown in varying mixture ratios. A clinal trial using the design of Vanclay (2006) was established in Leyte Leyte in December 2007 using four species. This trial will provide important information on ideal spacing at which trees should be established and how initial planting density affects site capture and early growth, especially in respect to indigenous species. Field trials have also been established to investigate the effect of fertiliser and shade on the establishment and early growth of mayapis and to demonstrate the positive impact that the use of high quality germplasm and good early age silviculture has on the growth of gmelina. The establishment of the field trials has been an important capacity building exercise within the project team. Filipino collaborators have been intimately involved in the design, establishment and monitoring of the field trials and are now capable of establishing similar rigorous field experiments

    Compendium of Volume Equations for Plantation Species used by the Queensland Department of Forestry

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    More then two hundred volume equations for plantation species used by the Queensland Department of Forestry are provided. The history of volume table use, method of computation and four categories of equation: predominant height, total height, merchantable height and small end diameter equations, are described. The specific form and Departmental identification of each equation are given

    What Would a Global Forest Convention Mean for Tropical Forests and for Timber Consumers?

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    A global forest convention has been advocated for about 15 years, but progress is slow and positions of advocates and opponents appear entrenched. We review several case studies and offer new empirical evidence relating to causes of and remedies for deforestation. We find no evidence to suggest that a forest convention will be effective in halting deforestation. Our data indicate that development assistance may be most effective approach to save forests in developing countries. It appears that "money speaks louder than words". We conclude that a global forest convention will be ineffective unless accompanied by substantial and well-directed development assistance

    Realizing Opportunities in Forest Growth Modelling

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    The world is continually changing: the emergence of new technology and new demands for pertinent information pose new challenges and possibilities for forest management. Are forest growth models keeping up with client needs? To remain relevant, modelers need to anticipate client needs, gauge the data needed to satisfy these demands, develop the tools to collect and analyze these data efficiently, and resolve how best to deliver the resulting models and other findings. Researchers and managers should jointly identify and articulate anticipated needs for the future, and initiate action to satisfy them. New technology that offers potential for innovation in forest growth modelling include modelling software, automated data collection, and animation of model outputs. New sensors in the sky and on forest machines can routinely provide data previously considered unattainable (e.g., tree coordinates, crown dimensions), as census rather than sample data. What does this revolution in data availability imply for forest growth models, especially for our choice of driving variables

    Establishing field trials to promote smallholder forestry in Leyte, The Philippines

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    The quality of planting material is one of the key factors that determine the success of tree farming and reforestation activities. In the Philippines, low quality seedlings are commonly used in smallholder plantings for reasons such as the limited supply of high quality seedlings and smallholders’ lack of awareness of the benefits of using high quality planting stock. The ACIAR-funded seedling enhancement project has been carrying out training and extension activities to enhance the knowledge of tree farmers about the importance of high quality planting material and improve the capacity of nursery operators in the production of high quality seedlings. Various field trials were established to gain new knowledge on tree farming and to demonstrate to smallholders the result of adopting the best management practices

    Initial gas exchange results from field trials

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    Gas exchange measurements were undertaken at field trials to investigate the impact of thinning of 12 year old gmelina plantations located at Bato. Amax for leaves at the thinned site were significantly higher (pnarra>mahogany>mayapis. This pattern is also reflected in the average height of each species but not in the pattern for average biomass (number of leaves) and dbh which followed the pattern of falcata>mahogany>narra>mayapis. The reversal of mahogany and narra suggests a different pattern of resource allocation. Narra has high rates of Amax with a smaller number of leaves compared with mahogany which has a lower rate of Amax but a much greater number of leaves and total leaf biomass. There was a substantial difference between the light curves for 11 month old gmelina trees in the three experiment plots with a 3 m x 3 m spacing compared with gmelina trees in the one experimental plot with a 4 m x 4 m spacing (Figure 6). The preliminary interpretation of these results is that at even a very early age, resources are becoming limiting for photosynthesis at a 3 m x 3 m spacing. This unexpected finding will be investigated further with a variable spacing trial

    Improving Productivity in Mixed-Species Plantations

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    Mixed species plantations are often promoted as being environmentally preferable to monocultures, but are rarely considered operationally viable by commercial forest growers. Despite many publications documenting benefits demonstrated in research studies, and despite continuing calls from a wide range of advocates for mixed-species plantations, polyculture remains the exception rather than the rule in industrial plantation forestry. The following observations are drawn from a recent workshop: - innovative experiment designs and analytical techniques are available to examine species interactions; - despite the enthusiasm for polycultures, relatively few robust experiments have been established, and even fewer have been maintained long enough to allow rotation-length consequences to be evaluated; - commercial polyculture plantations are even more scarce than experiments, and rarely offer data to support publication of financial analyses; - small landholders appear to be the main innovators in establishing and demonstrating polyculture plantations. To provide the evidence to encourage industrial uptake of polyculture plantations, there is a need for - a co-ordinated series of long-term trials, well replicated in time and space, using a standardised design with several treatments (species composition) and comparable species; - operational-scale demonstration plantings that gather ecological, financial and social data as well as the conventional production data

    Deforestation: Correlations, Possible Causes and Some Implications

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    Changes in national forest areas during 1990-2000 are contrasted with other variables to illustrate correlations and provoke discussion about possible causes. Twenty-five statistically-significant correlations (including rural population, life expectancy, GDP, literacy, commerce, agriculture, poverty and inflation) are illustrated and a statistical model suggests that good governance, alternative employment opportunities, and payments for environmental services may be effective in combating deforestation. The data suggest that a global forest convention may need to be supported by substantial and carefully-targeted development assistance to foster good governance

    Assessing the Quality of Permanent Sample Plot Databases for Growth Modelling in Forest Plantations

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    Informed plantation management requires a good database, since the quality of information depends on the quality of data, growth models and other planning tools. There are several important questions concerning permanent plots: how many plots, where to put them, and how to manage them. Plot measurement procedures are also important. This paper illustrates graphical procedures to evaluate existing databases, to identify areas of weakness, and to plan remedial sampling. Two graphs, one of site index versus age, another with stocking versus tree size, may provide a good summary of the site and stand conditions represented in the database. However, it is important that these variables, especially site index, can be determined reliably. Where there is doubt about the efficacy of site index estimates, it is prudent to stratify the database according to geography, soil/geology or yield level (total basal area or volume production). Established permanent plot systems may sample a limited range of stand conditions, and clinal designs are an efficient way to supplement such data to provide a better basis for silvicultural inference. Procedures are illustrated with three data sets: teak plantations in Burma, Norway spruce in Denmark, and a clinal spacing experiment in India
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