Forestry: Recent submissions
Now showing items 41-55 of 55
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Alley coppice—a new system with ancient rootsContext: Current production from natural forests will not satisfy future world demand for timber and fuel wood, and new land management options are required. Aims: We explore an innovative production system that combines the production of short rotation coppice in wide alleys with the production of high-value trees on narrow strips of land; it is an alternative form of alley cropping which we propose to call ‘alley coppice’. The aim is to describe this alley coppice system and to illustrate its potential for producing two diverse products, namely high-value timber and energy wood on the same land unit. Methods: Based on a comprehensive literature review, we compare the advantages and disadvantages of the alley coppice system and contrast the features with well-known existing or past systems of biomass and wood production. Results: We describe and discuss the basic aspects of alley coppice, its design and dynamics, the processes of competition and facilitation, issues of ecology, and areas that are open for future research. Conclusion: Based on existing knowledge, a solid foundation for the implementation of alley coppice on suitable land is presented, and the high potential of this system could be shown.
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Soil carbon stocks in a Sitka spruce chronosequence following afforestationIncreasing concentrations ofCO2 and other greenhouse gases in the atmosphere are leading to concern worldwide due to their contribution to the greenhouse effect. As the body of evidence supporting the need for change from a carbon rich economy/society becomes stronger, international mitigation agreements require high quality and precise information. Following the Kyoto Protocol and EU agreements to reduce carbon production, countries could utilise default values or comparable international data to calculate their carbon budgets. Initially, approximations were successful for generating a guide to a national carbon stock for reporting GHG inventories to the UNFCCC (Tier 1 ). However, now that the second phase of the Kyoto protocol is running until 2020, greater accuracy is essential and, where possible, nationally specific information is increasingly required (Tier 3, UNFCCC). Forestry and forest soils are seen as a key component in the carbon cycle and depending on their management, can mitigate or contribute to GHG emissions. Litter and soil organic matter (SOM) are two of the major carbon pools required for reporting under LULUCF. In this study, stocks of SOM and litter were recorded along a chronosequence of Sitka spruce (Picea sitchensis (Bong.) Carr.) on wet mineral gley soil. Over a 47-year period, the rate of soil carbon sequestration was found to be 1 .83 t C ha−1 yr−1 . Soil microbial biomass was used to estimate highly active SOM. The mineral soils were also fractionated in a density separation procedure to identify light and heavy SOM pools. These estimates can now be used to model carbon budgets of this most common soil type currently under forestry in Ireland.
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The Irish Forest Soils Project and its Potential Contribution to the Assessment of BiodiversityThe United Nations Environment Programme (UNEP) has proposed methods and thematic areas for data collection that are appropriate to the evaluation of biodiversity. The Heritage Council has identified a paucity of data on habitats in Ireland. Within this context, we outline the Irish Forest Soils (IFS) element of the Forest Inventory and Planning System (FIPS) and present a detailed account of land-cover mapping, which is an important aspect of the project. The IFS project aims to produce a national thematic map of land cover using soft-copy photogrammetry, combined with satellite-image classification and field survey. This aspect of the IFS project generates data on land cover at different spatial and classification resolutions. We report on the progress made to date and present illustrative examples of the data sets. The UNEP proposals provide a useful framework within which to discuss the potential contribution of IFS data to the assessment of biodiversity.
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Tending and thinning of broadleaves: A simple guide to selecting quality trees.This article describes a simple procedure that can be used to ensure that the correct trees are selected in broadleaf woodland before tending / thinning is carried out, and follows best practice based on the latest Teagasc Forestry research.
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Coppice-with-standards: An old silvicultural system with new potential?The last two decades have seen a dramatic increase in the area of broadleaf afforestation in Ireland.Some of these plantations are not performing as well as was expected when planted. This article describes the coppice-with-standards silvicultural system. With the increased demand for fuelwood and greater broadleaf plantation area, some of which may require alternative silvicultural management to the conventional due to poor performance, the coppice–with–standards system has the potential to fulfil many objectives.
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The Potential Economic Returns of Converting Agricultural Land to Forestry: An Analysis of System and Soil Effects from 1995 to 2009Private land owners have been responsible for the majority of annual afforestation in Ireland since the mid1990s, but planting rates have generally been declining since 2002. Although the decision to plant may be driven by a number of factors, the profitability of forestry as a landuse option should be an important driver and offer some insight into trends in afforestation rates. As farmers undertake most afforestation in Ireland it is important to account for the opportunity cost of lost agricultural income when analysing the financial outcome of planting. In addition, soil quality plays an essential role in dictating the productivity and profitability of both agriculture and forestry. This study examines the effects of soil quality and superseded agricultural system on the potential profitability of afforestation by farmers between 1995 and 2009. Data from the National Farm Survey were employed to identify the annual gross margins for six agricultural systems on six soil types that differ in terms of quality. The measures of soil quality were translated into potential yield classes for forestry using an existing productivity model and Teagasc’s Forest Investment and Valuation Estimator was employed to calculate the net present value of afforestation for each of the systems and soil types. The results demonstrate how the competitiveness of forestry as a landuse option is influenced by soil quality and superseded enterprise and how forestry has become more competitive with agricultural enterprises over the period of analysis.
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The potential for using a free-growth system in the rehabilitation of poorly performing pole-stage broadleaf standsThis paper is a literature review of the free-growth system, which may have potential for the rehabilitation of some poorly-performing pole-stage broadleaf stands. It involves releasing of a selected number of good quality stems from crown competition as a basis for the final crop. Generally, only stems with crowns adjacent to the potential final crop trees are removed. The aim is to increase diameter growth of the selected stems and thereby shorten the rotation length needed to achieve a given diameter. The treatment may result in a greater incidence of epicormic shoots, particularly in oak (Quercus spp.). To maintain stem quality, epicormics may need to be removed, which may make the free-growth system uneconomic. There is, however, some evidence to believe that this may not be the case. In addition, the free-growth system may also be applicable in species less prone to epicormics, such as ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus L.). The free-growth system may prove to be a useful system for the rehabilitation of poorly performing pole-stage broadleaf stands and, with the advent of Chalara ash dieback (caused by Hymenoscyphus pseudoalbidus V. Queloz et al.) in Ireland, may gain greater use for its ability to reduce rotation lengths.
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Establishment of a bovine/Quercus silvopastoral experiment in lowland Ireland.A silvopastoral experiment was established at Teagasc in County Wexford, Ireland, in 2002 with oak (Quercus robur L.) in an alley design and bovines. The experiment includes some treatments with trees produced with an enhanced root system (RPM). The treatments are: (1) control pasture plots; (2) RPM agroforestry (400 stems/ha); (3) conventional agroforestry (400 stems/ha); (4) RPM forestry (6600stems/ha; and (5) conventional forestry (6600 stems/ha). The trees were successfully established and cattle were successfully managed in combination with the trees. In the first year, height growth of bare-root oaks was significantly greater in the forestry treatment compared to the agroforestry treatment and, overall, RPM oaks were taller than bare-root plants. Among the RPM trees, the agroforestry system resulted in a greater stem diameter than those in the forestry plots. Height increment was greater for RPM trees than for bare-root trees.
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High levels of variation in Salix lignocellulose genes revealed using poplar genomic resourcesBackground: Little is known about the levels of variation in lignin or other wood related genes in Salix, a genus that is being increasingly used for biomass and biofuel production. The lignin biosynthesis pathway is well characterized in a number of species, including the model tree Populus. We aimed to transfer the genomic resources already available in Populus to its sister genus Salix to assess levels of variation within genes involved in wood formation. Results: Amplification trials for 27 gene regions were undertaken in 40 Salix taxa. Twelve of these regions were sequenced. Alignment searches of the resulting sequences against reference databases, combined with phylogenetic analyses, showed the close similarity of these Salix sequences to Populus, confirming homology of the primer regions and indicating a high level of conservation within the wood formation genes. However, all sequences were found to vary considerably among Salix species, mainly as SNPs with a smaller number of insertions-deletions. Between 25 and 176 SNPs per kbp per gene region (in predicted exons) were discovered within Salix. Conclusions: The variation found is sizeable but not unexpected as it is based on interspecific and not intraspecific comparison; it is comparable to interspecific variation in Populus. The characterisation of genetic variation is a key process in pre-breeding and for the conservation and exploitation of genetic resources in Salix. This study characterises the variation in several lignocellulose gene markers for such purposes.
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COST E42 Growing Valuable Broadleaves Silviculture Matrix: An Irish exampleThe purpose of developing the silvicultural matrix in COST E 42 was to provide a vehicle whereby information on silviculture of valuable broadleaved species could be gathered from as many participating countries as possible. The aim of this matrix is to determine what are considered the optimum silvicultural treatments for each of our target species in countries across Europe. In many cases only one or two countries will have experience of a particular species. Also it must be realised that, for many of the larger countries in Europe, there are different climatic regimes and no single matrix can encapsulate the recommendations for that country. In this case a number of climatic regional matrices would be preferable. For this reason, not all countries felt in a position to contribute a matrix and preferred to provide a narrative discussion on various species. As an illustration of how the matrix can provide a guideline for farmers wishing to plant, the example of ash (Fraxinus excelsior L.) in Ireland is taken. Based on the research we carried out, we developed a set of guidelines to assist farmers in making critical decisions. These guidelines now form the basis for government support to farmers.
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Possible silvicultural systems for use in the rehabilitation of poorly performing pole-stage broadleaf stands - Coppice-with-standardsThis paper is a review of the coppice-with-standards system, a system that may have potential for the rehabilitation of some poorly performing pole-stage broadleaf stands. The system was once a very common system throughout Europe, producing much needed fuelwood and sawlog. Its decline in Ireland, the UK and elsewhere was primarily due to market forces. This review was conducted because the system may have potential once again due to the recent increased demand for firewood. Coppice-with-standards can provide material of various sizes to supply local demand for fuelwood, pulpwood, fencing material and sawlog. The system also has nonmarket benefits such as amenity and biodiversity values. One disadvantage of the system is that it requires greater silvicultural skill to manage to a high standard. The coppice-with-standards system is being trialled as a means to rehabilitate a poorly performing 19-year-old stand of ash:oak mixture.
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Poor performance of broadleaf plantations and possible remedial silvicultural systems - a reviewOver the last two decades planting of broadleaves has been part of forest policy. In addition to the provision of a range of ecosystem services, it is intended that this resource will have a direct economic stimulus through the supply of quality hardwood. A number of challenges must be met in order to achieve this objective, particularly as current observations would indicate that many first rotation broadleaf plantations comprise a relatively high proportion of poor quality stems. A literature review has been carried out on the probable causes of poor performance in broadleaf crops. Silvicultural systems to rehabilitate poor quality stands are discussed. Subsequent papers will deal with these silvicultural systems in more detail.
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Management of young forestsEarly management is essential to get the best returns from your forest in the future. New plantations require several years of active management to become well established. The payment of the second instalment of the Afforestation Scheme (Maintenance Grant) and forestry premium is subject to the forest successfully achieving certain standards. If a plantation is not well maintained, future timber revenue is likely to be compromised.
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Silvicultural Guidelines for the Tending and Thinning of BroadleavesThis publication provides guidelines for the tending and thinning of ash, alder, sycamore, Norway maple, oak and beech. Some silvicultural procedures to follow during these operations are also provided.