Now showing items 21-40 of 52

    • Investigating the impact of varying levels of inventory data detail on private sector harvest forecasting

      Farrelly, Niall; O'Connor, Cian; Nieuwenhuis, Maarten; Phillips, Henry; Department of Agriculture, Food and the Marine; 14/C/824 (The Society of Irish Foresters, 2019-02-01)
      A comparison was made between four methods of generating roundwood production forecasts for private sector forests in Ireland which used varying levels of inventory data as inputs into the production Model. Two methods were based on stand variables: the Irish Dynamic Yield Model (IDYM) method and the General Yield Class (GYC) method. The other two methods were based on site variables used to derive predictions of productivity from climate and map-based data and include a local prediction (LPYC) and a national prediction of yield class (NPYC), the latter the same as that used in the All Ireland Roundwood Production Forecast 2016-2035 (Phillips et al. 2016). To determine the reliability of predictions for an individual stand, field measurements of yield class (GYC) were compared with the predictions of yield class derived using the NPYC and LPYC methods for 52 privately-owned stands of Sitka spruce in the north-west of Ireland. The prediction of yield class using the NPYC method had a low probability of agreement with GYC, with a large bias to under-predict yield class. The LPYC method had a higher probability of agreement and lower bias indicating a better assessment of local productivity. To assess the impact of the various productivity estimates on roundwood production forecasts, separate roundwood forecasts for the period 2016- 2035 were generated. The forecast produced using the NPYC method was used as a baseline for comparison purposes. As expected, the under-prediction of yield class using the NPYC method produced the lowest volume production estimate (318,454 m3) for the forecast period. Both the GYC and LPYC methods resulted in a significant increase in estimated volume production of between 25% and 29% over the baseline. The IDYM method provided the highest estimate of volume production (432,000 m3) for the forecast period, an increase of 35% over the baseline. The increased output predicted using the IDYM method is explained by the inclusion of stocking and basal area data, which more accurately reflected the increased growing stock of private forests than yield data derived using Forestry Commission yield models based on prescribed management. The increases in productivity associated with the use of LPYC, GYC and IDYM methods had the effect of producing shorter rotations and resulted in an increase in the area clearfelled and associated volume production. Perhaps more importantly, the timing of volume production was affected by using more accurate methods to assess productivity (i.e. LPYC, GYC, IDYM), owing to a higher yield-age profile of stands compared to those assessed using the NPYC predictions. The findings point to a possible under-estimation of the productivity for private stands in the All Ireland Roundwood Production Forecast and have implications for the timing of the forecasted volume which could be brought forward by 5 to 6 years. In the absence of field or aerial laser measurement of height and age, the use of the LPYC method is recommended for future private sector roundwood producion forecasts.
    • A Response to the Draft National Mitigation Plan. Teagasc submission to the Department of Communications, Climate Action & theEnvironment

      Lanigan, Gary; Donnellan, Trevor; Hanrahan, Kevin; Gultzer, Carsten; Forrestal, Patrick J.; Farrelly, Niall; Shalloo, Laurence; O’Brien, Donal; Ryan, Mary; Murphy, Pat; et al. (Teagasc, 2017-04)
      This submission details the mitigation potential of agriculture to shortly be published as an update to the Marginal Abatement Cost Curve (MACC) for Agriculture and and describes how the MACC mitigation strategies relate to the measures in the National Mitigation Plan.
    • Impact of competition on the early growth and physiological responses of potential short-rotation forestry species in Ireland

      Foreman, Susie; Department of Agriculture, Food and the Marine; 13/C/498 (2019-07)
      The impact of planting density on the growth and physiological response of three potential short rotation forestry species, shining gum (Eucalyptus nitens (Deane & Maiden) Maiden), Italian alder (Alnus cordata (Loisel.) Duby) and Sitka spruce (Picea sitchensis (Bong.) Carrière) were investigated in this study over a four-year period. The three species were planted in a field trial in Co. Wexford. The trial was laid down as a randomised block design containing four planting densities (1,333 – 40,000 stems ha-1) per species. Height, stem diameter, branch length, diameter and quantity, crown height, along with shade leaf only determinations of leaf area and leaf dry weight, chlorophyll concentration (Chleaf) and photosynthesis rates (PN) were measured periodically over the 4-year period. E. nitens trees produced the shallowest live crown of the three species, which decreased as planting density increased. Chleaf declined as planting density increased, but PN remained the same. E. nitens produced the greatest volume and biomass per ha-1 of the three species at the end of four years growth. Height increased and stem diameter decreased as planting density increased in A. cordata, although stem volume remained about the same. However, planting density did not affect crown volume or Chleaf in A. cordata, but PN declined as density increased. Trees of P. sitchensis grew more slowly than those of the other species during the four-year period, but it produced the densest crown at all planting densities. Competition effects were apparent at leaf level in P. sitchensis. Planting density did not affect the above-ground biomass in A. cordata or P. sitchensis, which was similar for the two species and was lower than that recorded for E. nitens. Of the three species examined, E. nitens was the most productive at all planting densities.
    • Comparison of photosynthetic performance of Fagus sylvatica seedlings under natural and artificial shading

      Sevillano, Ignacio; Short, Ian; Campion, Jerry; Grant, Olga M.; Grant, Jim; O’Reilly, Conor; Department of Agriculture, Food and the Marine; Teagasc Walsh Fellowship Programme (Elsevier, 2018-03-14)
      Commitment to sustainable forest management (alternatives to clearfelling) has led to a renewed interest in continuous cover forestry systems, which promote the control of light to produce stand benefits. Physiological performance of shade-tolerant European beech (Fagus sylvatica L.) in response to light availability was investigated in natural regeneration below the canopy in contrast to planted seedlings under artificial-shade conditions. Although beech seedlings had higher photosynthetic capacity with increasing light availability, they were able to maintain positive CO2 assimilation rates under low light levels in both field and controlled conditions. Leaves of seedlings under low light had the ability to use light more efficiently (higher PSII efficiency) than those in high light, which offer some physiological explanation for the ability of beech seedlings to grow under very low light conditions. Whilst caution is advised to interpret results from controlled to field studies, the overall general correspondence in the trend of the physiological response to light levels within beech grown below the canopy and under artificial-shade conditions suggests that it might be possible to extrapolate results from studies performed under artificial shade (nets) to field conditions. Hence, the use of nets may be an alternative way of assessing the potential physiological responses of seedlings to light availability.
    • Ash dieback in Ireland – A review of European management options and case studies in remedial silviculture

      Short, Ian; Hawe, Jerry; Woodland Trust NI; COFORD; Teagasc (Society of Irish Foresters, 2018)
      Ash dieback, caused by Hymenoscyphus fraxineus, is developing rapidly across the island of Ireland. Ireland’s ash (Fraxinus excelsior L.) woodlands, particularly first rotation plantations, are quite unique and are at particular risk of very rapid decline. Urgent action is required in order to minimise the economic, ecological and social impact of the disease. However, for this to happen forest owners require guidance regarding potential positive management interventions. This article outlines the wider, mainly European, experience of remedial silviculture. It presents three case studies on existing remedial silviculture trials in Ireland. In the absence of silvicultural research data specific to the evolving situation with ash dieback, this article explores the potential benefits of positive practical actions which may minimise the impact of the disease. Despite the seriousness of the situation, such silvicultural activity may even result in a positive economic outcome. It is hoped that by beginning to document potential mitigatory management options, this paper may bring some reassurance to owners and managers of ashdominated woodlands.
    • Continuous Cover Forestry: The rise of transformational silviculture

      Wilson, Edward; Short, Ian; Ni Dhubhain, Aine; Purser (2018)
      CCF has been a popular discussion topic in forestry circles for some time. Now a body of research and an increasing number of working examples are demonstrating the true potential of this flexible and resilient silvicultural approach. Here, Edward Wilson, Ian Short, Áine Ní Dhubháin and Paddy Purser comment on current developments
    • Transforming Sitka spruce plantations to continuous cover forestry

      Wilson, Edward; Short, Ian; Ní Dhubháin, Áine; Purser, Paddy; Teagasc; RMIS 0138 (Select Media, 2018-03)
      Identifying potential crop trees and regular thinning are the keys to successful transformation of plantations to resilient, continuous cover forests. By Edward Wilson, Ian Short, Áine Ní Dhubháin and Paddy Purser.
    • Vegetative propagation of dieback-tolerant Fraxinus excelsior on

      Douglas, Gerry C.; Namara, J.M.; O'Connell, K.; Dunne, L.; Grant, Jim; European Co-Operation in Science and Technology; FP1103 (Swedish University of Agricultural Sciences, 2017)
      Ash trees which are tolerant to Hymenoscyphus fraxineus may be selected in all age classes among heavily infected populations. They may be produced also by controlled crossings of disease tolerant trees, because the genetic component of inheritance for disease tolerance is high. For mature and juvenile plant material, the deployment of disease tolerant genotypes could be potentially achieved by vegetatively propagating selected genotypes. We describe a system to vegetatively propagate selected ash genotypes and we discuss the prospects and options for using vegetative propagation on all age classes of trees. Mature trees were rejuvenated through the process of micropropagation to establish mother plants in large trays which were cut back repeatedly (hedged) to produce at least two crops of cuttings per year. The rooting capacity of ten genotypes was tested by a commercial nursery over a period of three years, to assess the feasibility of using hedged mother plants for efficient propagation. Commercial practise was to treat cuttings with 0.25% IBA, insert them in plug pots and maintain them covered with fine plastic within low plastic tunnels in a non heated greenhouse and without supplementary heating at the cutting base. In the first year, the mean rooting rate was 53 % for the first crop of cuttings and 35 % for the second. In the second and third years the rooting rates improved to over 80% for each crop of cuttings as experience was gained in handling the material. Rooting rate varied among the genotypes. We assessed the growth and development of micropropagated ash trees in the field from an observation clonal trial, consisting of four mature genotypes which had been established in 2002 in five replicate plots. The micropropagated trees were generally similar in height and dbh to seed derived control trees and developed normally. These observations are discussed in the context of using vegetative propagation as a tool in breeding and for the large scale deployment of ash with tolerance to H. fraxineus.
    • Ash dieback on the island of Ireland

      McCracken, A.R.; Douglas, Gerry C.; Ryan, C.; Destefanis, M.; Cooke, L.R.; European Co-Operation in Science and Technology (Swedish University of Agricultural Sciences, 2017)
      On the island of Ireland it is estimated that there are over half a million kilometres of hedgerows (400,000+ km in the Republic of Ireland (Rep. Ireland) and 113,000+ in Northern Ireland (Northern Ireland). Ash (Fraxinus excelsior) is the second most important component, after hawthorn (Crataegus monogyna), in large proportions of this hedgerow network. In the Rep. Ireland over 20,000 ha of ash have been planted since 1990, primarily for sawlogs and to provide material for the manufacture of hurleys, which are used in an important national sport called hurling, and for camogie sticks used to play camogie. Ash dieback, caused by Hymenoscyphus fraxineus, was first identified on the island in October 2012 and since then has been detected at 306 sites (195 in Rep. Ireland and 111 in Northern Ireland). In the vast majority of cases the outbreaks have been on young, imported trees planted within the previous 5 – 6 years and it was evident that the pathogen had been introduced on trees for planting. On a small number of occasions there was evidence of the pathogen cycling within a plantation or moving from the plantation to infect neighbouring hedgerow trees. One possible mechanism by which the pathogen can build up sufficient inoculum is by the formation of apothecia on infected woody tissue high up on the plants. Rep. Ireland and Northern Ireland have strict policies of eradication and containment, as set out in the All-Ireland Chalara Control Strategy. To date over 2.1 million trees have been destroyed as part of an eradication strategy. It is considered that this prompt and far-reaching action has had a significant impact, significantly mitigating and preventing the rapid establishment of the pathogen and limiting its spread. The interventions since the disease was first confirmed have helped to protect the considerable investment in ash plantations of the last 20 years. The pathogen has not, however, been eradicated from the island of Ireland and it remains to be seen how widespread, and how quickly ash dieback will become established on the island of Ireland. The latest figures from the Republic of Ireland are that 733 hectares of ash plantation has been reconstituted with another species as a result of Chalara and this has cost our state €2.6 million so far; in addition, Chalara has been found and confirmed in all 26 counties of the Republic of Ireland to a greater or lesser extent. As a result the current policies and procedures regarding Chalara are under review.
    • Morphological and physiological responses of Fagus sylvatica and Quercus robur seedlings to light availability

      Sevillano, Ignacio; COFORD; Teagasc Walsh Fellowship Programme (2016-06)
      The need to develop forest management systems other than clearfelling has resulted in a requirement for improved understanding of the potential of continuous cover forestry (CCF). One suggested method for the conversion of forest stands into CCF systems and for bringing under-performing forests into productivity is thinning in conjunction with underplanting. This study was an attempt to provide information on species suitability for underplanting of two important trees in European forestry: pedunculate oak (Quercus robur L.) and European beech (Fagus sylvatica L.). To determine the morphological, physiological and growth responses of these two species to different light conditions, beech and oak seedlings previously grown at full light for two years were covered by shading nets that provide different shade levels (62%, 51% or 28% of full light) or continued to be exposed to full light. The different shade levels were intended to mimic a range of underplanted conditions and the process of acclimation to shade was studied to provide information on the ecology and adaptation of underplanted seedlings. In addition to the controlled-shade experiment another study to determine the physiological responses of beech natural regeneration to shade was conducted under natural light conditions (from open gaps to closed canopy). Both oak and beech displayed similar acclimation in response to shade for most of the traits investigated. At the plant level, seedling acclimation to shade included higher biomass allocation to above than below-ground parts and greater energy investment on height than diameter growth. At the leaf level, seedlings grown under shade reduced their leaf thickness and photosynthetic rates per unit area and increased their specific leaf area. This increase in specific leaf area seems to be one mechanism that allows seedlings to perform well under shade conditions. Another acclimation to low light conditions was to increase the efficiency of the photosystem II under shade. Photosynthetic rates were higher and leaves were retained for longer in seedlings grown at full light than under shade. Hence, this probably led to a greater growth in the full light than under shade. Despite this greater growth at full light, the results of this study suggest that beech and oak seedlings would be able to acclimate and perform well if underplanted below overstories that reduce the available light to as low as 28% of full light without having any significant adverse effect on the quality of the final crop.
    • Broadleaf thinning in Ireland - a review of European silvicultural best practice

      Hawe, Jerry; Short, Ian; Department of Agriculture, Food and the Marine, Ireland (Society of Irish Foresters, 2016)
      A substantial first-rotation broadleaf plantation resource in Ireland is progressively entering a thinning phase. Silvicultural best practice in support of such a management intervention needs to be developed for this new woodland resource to achieve its maximum commercial potential. National research trials are key to the provision of information for the development of best practice. Determining the current state-of-the-art is a prerequisite to the design and implementation of appropriate research trials. This study reviews the literature concerning the fundamental principles of broadleaf thinning with particular regard to timing, intensity and impacts on crop tree growth response, focussing on a range of commonly planted broadleaf species in Ireland. The overall aim of this review is to gain a fuller understanding of the most effective thinning methodology to be employed to maximise the production of high quality hardwood timber. In doing so it is intended that the information presented may support ongoing and future research trials with regard to potential silvicultural treatments to apply, data types and analysis and the likely results of practical application to commercial forestry.
    • A review of stumping back and case study of its use in the rehabilitation of poorly performing pole-stage sycamore

      Short, Ian; Hawe, Jerry; Campion, Jerry; Byrne, Ricky; COFORD (Society of Irish Foresters, 2015-12)
      First rotation broadleaf plantations present a range of inherent challenges to the achievement of good form and vigour. Where biotic and/or abiotic factors compromise early growth and stem quality, appropriate management interventions to improve these are required. An historical review of “stumping back” literature is presented together with a case-study. The B-SilvRD broadleaf silviculture research project includes a “rehabilitation” strand, whereby innovative measures to improve poorly performing stands of commercial broadleaves are being trialled. One such pilot trial involves a 17year-old sycamore (Acer pseudoplatanus L.) plantation, which had not performed well and required significant intervention to improve its silvicultural and economic viability. This paper reviews the literature on stumping back and presents a case-study with results of three different line thinning/stumping back treatments, including analysis of different light regimes and the impact of light levels on coppice regrowth.
    • Projections of forestry as a competitor with mainstream agricultural enterprises and the consequent environmental implications

      Donnellan, Trevor (Teagasc, 01/01/2007)
      Through its relationship with the Food and Agricultural Policy Research Institute (FAPRI), staff at the Rural Economy Research Centre (RERC) have developed a system of econometric models of the Irish Agriculture sector. The output from these models includes, amongst other things, projections of agricultural activity levels under different policy options. From an environmental perspective, information on future levels of agricultural activity are important since they can facilitate the calculation of aggregate national levels of emissions of various pollutants from agriculture. The project has also produced a model which makes projections of forestry planting.
    • How remedial silviculture can improve poorly performing pole-stage broadleaves

      Short, Ian; Campion, Jerry (Select Media Ltd., 2015-08)
      The last 20 years has seen the planting of 30,000 hectares of broadleaf trees in Ireland. Action must be taken to achieve the best return on this investment, writes Dr. Ian Short and Jerry Campion, Teagasc Forestry Development Department.
    • The impact of shade on photosynthetic characteristics in Fagus sylvatica and Quercus robur seedlings

      Sevillano, Ignacio; Short, Ian; O'Reilly, Conor (Teagasc, 10/03/2014)
    • European Mixed Forests: definition and research perspectives

      Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian; Andenmatten, Ernesto; Barbati, Anna; Barreiro, Susana; Brang, Peter; Bravo, Felipe; Coll, Lluis; Corona, Piermaria; et al. (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2014-11)
      Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) briefly review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material and methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any developmental stage, sharing common resources (light, water, and/or soil nutrients). The presence of each of the component species is normally quantified as a proportion of the number of stems or of basal area, although volume, biomass or canopy cover as well as proportions by occupied stand area may be used for specific objectives. A variety of structures and patterns of mixtures can occur, and the interactions between the component species and their relative proportions may change over time. The research perspectives identified are (i) species interactions and responses to hazards, (ii) the concept of maximum density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields of research indicate that gradient studies, experimental design approaches, and model simulations are key topics providing new research opportunities.
    • Physiological Responses of Fagus sylvatica and Quercus robur Seedlings to Light Intensity

      Sevillano, Ignacio; Short, Ian; O'Reilly, Conor; Grant, Olga M.; COFORD (FESPB/EPSO, 22/06/2014)
      Broadleaf planting has become increasingly important in Ireland over the recent years and light is recognised as one of the main environmental factors affecting stand development, but to date there has been little research on broadleaf responses to light intensity, particularly in Ireland. Continuous cover forestry (CCF) is increasing as an alternative to clear-cutting and uses the control of light to produce plantation benefits. The physiological responses of beech (Fagus sylvatica) and oak (Quercus robur) seedlings to four different shade environments (100%, 62%, 51% and 28% of incident photosynthetically active radiation, PAR) were studied in a shadehouse experiment during the summer of 2013. Light-response curves (only measured in the extreme treatments) differed between beech seedlings of the Control treatment (PAR=100%) and those of the heavy shade treatment (PAR=28%) when PAR > 100 μmol m-2 s-1, while there was little difference for oak between both treatments. Light-response curves generally showed maximum photosynthetic rates (Amax) at 1500 μmol m-2 s-1 in both treatments, and this PAR value was used while measuring stomatal conductance (gs) and water use efficiency (WUE). Significantly higher values of Amax and gs were found in oak than in beech in the 62%, 51% and 28% treatments. There were no significant differences between oak and beech for Amax and gs in the Control treatment or for WUE in the four treatments.
    • Alley coppice—a new system with ancient roots

      Morhart, Christopher D.; Douglas, Gerry C.; Dupraz, Christian; Graves, Anil R.; Nahm, Michael; Paris, Perluigi; Sauter, Udo H.; Sheppard, Jonathan; Spiecker, Heinrich; European Commission (Springer, 2014-05)
      Context: 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.
    • Soil carbon stocks in a Sitka spruce chronosequence following afforestation

      Reidy, Brian; Bolger, Thomas; COFORD (Society of Irish Foresters, 2013)
      Increasing 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.