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Martin-Rodrigues N.,University of the Basque Country | Sanchez-Zabala J.,University of the Basque Country | Salcedo I.,University of the Basque Country | Majada J.,Forest and Wood Technology Research Center | And 2 more authors.
Plant Pathology | Year: 2015

Pine root infection by Fusarium circinatum has been reported in the literature, but the underlying pathogenic interaction is poorly understood. A green fluorescent protein (GFP)-tagged F. circinatum isolate, together with confocal microscopy, was used in order to monitor the events associated with root infection of Pinus radiata seedlings. It was found that in order to reach and successfully infect pine roots, F. circinatum employed features that are similar to those previously described for other root-infecting pathogens, such as mycelial strands, single runner hyphae and simple hyphopodia as well as other features that are reminiscent of those that are known to be involved in biotrophic invasion, such as bulbous invasive hyphae and filamentous invasive hyphae. Abundant sporulation was observed at the root surface as well as inside tracheids both in roots and in the root collar region. The fungus can spread from the roots to the aerial parts of the plant, and once there, colonization appears to be similar to the process that occurs when the pathogen is inoculated in the stem. Wilting symptoms and plant demise may be the result of a reduction in water uptake by roots and of the blockage of the vascular system by fungal hyphae and resin. © 2015 British Society for Plant Pathology.


Sanchez-Garcia S.,Forest and Wood Technology Research Center | Canga E.,Forest and Wood Technology Research Center | Tolosana E.,Technical University of Madrid | Majada J.,Forest and Wood Technology Research Center
Croatian Journal of Forest Engineering | Year: 2016

The objective of this study was to evaluate the productivity and costs of two Spanish forwarders, models Dingo AD-8468 and AD-2452, in the hauling of bundles of residues after Eucalyptus globulus clear cuts on steep terrain in Northern Spain. In addition, various models to predict time consumption for the main work elements and productivity were fitted including several independent variables previously selected using stepwise regression. Finally, the models explain between 83% and 97% of variability. Since the equations are based on simple variables (depending on each individual equation this was either velocity empty and loaded, slope loading, distance empty/loading/loaded or load per cycle), they will be a helpful and easy to use tool to assist in forest management planning. Productivity was 6.75 odt/PMH for the Dingo AD-8468 forwarder and 11.56 odt/PMH for the Dingo AD-2452. Cost per tonne for the Dingo AD-8468 was 6.77 €/odt compared to 3.94 €/odt for the Dingo AD-2452. © 2016, University of Zagreb. All rights reserved.


Menendez-Miguelez M.,Forest and Wood Technology Research Center | Canga E.,Forest and Wood Technology Research Center | Barrio-Anta M.,University of Oviedo | Majada J.,Forest and Wood Technology Research Center | And 2 more authors.
Forest Ecology and Management | Year: 2013

Aboveground biomass was studied in Castanea sativa Mill. coppice stands in north-west Spain, and biomass equations were fitted at three levels (individual tree, stool and stand). Four systems of biomass estimation were developed. In two of the systems, the following individual tree variables were taken into account: standing tree variables and stump dimension variables. In the other two systems, biomass was estimated at stool and stand level, respectively.In order to represent the existing range of ages, stand densities and sites in the study area, samples of 120 trees (for the individual tree level), 45 stools (for the stool level) and 70 plots (for the stand level) were chosen for study. The trees were felled and destructively sampled to separate biomass into the following components: wood, bark, thick branches, medium branches, thin branches and leaves. Several equations for quantifying the biomass of the different biomass components were evaluated. Heterocedasticity was corrected for by weighted fitting. To guarantee the additivity of the different biomass components, the equations were fitted simultaneously by nonlinear seemingly unrelated regressions (NSURs).The different biomass levels considered accounted for between 60% and 90% of the total variability, depending on the level and component evaluated. Most of the equations developed in this study were evaluated with an independent dataset, which confirmed the good performance of the biomass equations for prediction purposes. © 2012 Elsevier B.V.


Sanchez-Garcia S.,Forest and Wood Technology Research Center | Canga E.,Forest and Wood Technology Research Center | Tolosana E.,Technical University of Madrid | Majada J.,Forest and Wood Technology Research Center
Applied Energy | Year: 2015

Given the complexity of generating energy from biomass, the need has arisen for support tools to assist in balancing energy and forestry policies which are sufficiently flexible to address the issues of planning and management at small and large scales.The present study aims to adapt WISDOM GIS methodology for application in the autonomous region of Asturias (Northern Spain) and thereby, by creating a geodatabase, to contribute to a support tool for investigating the potential of woodfuel. This will aid the public administration by providing information on woodfuel supply and demand at the regional, municipality and site-specific level, and thus assist in decision making in terms of formulating new energy strategies.In terms of supply (tyear- 1), in this work, woodfuel from forest area is defined as the crown fraction only (branches and leaves), although in the case of Eucalyptus spp., bark is also included as it is remains on-site following extraction of eucalypts for the pulp industry. Non-Forest Direct Supply was calculated on the basis of the relevant categories froman agricultural land use inventory and average woodfuel productivity. In addition, physical and legal constraints related to accessibility of the woodfuel were considered, the former applying restriction filters with values weighted depending on the interaction between slope map, road networks and centres of population, and the latter considering legal limitations in protected areas. In addition, unused waste from the wood processing industry was included. To calculate total woodfuel demand (tyear- 1) for energy generation (heat and electricity), both the residential and industrial sector were taken into account.All data was georeferenced through Geographic Information Systems (GISs), which allow operations between raster maps to be performed to generate numeric and spatial results focusing on logistics and biomass strategies, depending on the inputs data and scale employed for each scenario considered. In addition, the application of the methodology at the site-specific level illustrates the practical implementation at the small scale of the geodatabase created, by evaluating the woodfuel available to feed, in case 1, a wood-fired power plant in a specific proposed location and, in case 2, this plant combined with a second plant in a different municipality, both cases also taking into consideration industrial demand. © 2015 Elsevier Ltd.


Vega A.,Forest and Wood Technology Research Center | Dieste A.,Forest and Wood Technology Research Center | Guaita M.,University of Santiago de Compostela | Majada J.,Forest and Wood Technology Research Center | Bano V.,Forest and Wood Technology Research Center
European Journal of Wood and Wood Products | Year: 2012

Linear regression models were constructed for chestnut beams of Spanish origin (Asturias, Galicia, Catalonia and Extremadura) using the global modulus of elasticity (MOEg) and bending strength (MOR), both obtained by destructive tests, as dependent variables, and the results of non-destructive measurements, visual grading parameters and density as independent variables. The variables selected were density, wave velocity, sample length, dynamic modulus of elasticity, maximum knot diameter in relation to height and concentrated knot diameter ratio. Linear regression models were constructed to indirectly estimate the mechanical properties of the beams. Ultrasonic velocity, density and sample length were the best predictors of MOEg (R 2 = 0.740 and 0.734 SE). Regression adjustments for MOR presented low coefficients of determination and high errors. The visual grading parameters ofthe beams did not playa significant role in the prediction of either MOE g or MOR. © Springer-Verlag 2012.


Hevia A.,Forest and Wood Technology Research Center | Alvarez-Gonzalez J.G.,University of Santiago de Compostela | Majada J.,Forest and Wood Technology Research Center
European Journal of Wood and Wood Products | Year: 2016

Pruning is a key silvicultural intervention in order to obtain high quality wood products since it influences the size of the knotty core and the proportion of clear-wood. However, little is known about knotty core size and its distribution through the pruned stem in timber conifers. This paper describes methodologies to predict knotty core profile and form along the pruned stem as tools for helping in the estimation of wood quality before felling. For the first time, defects related to pruned branches and pruning intensity have been considered. Data of Pinus radiata and Pinus pinaster pruned standing trees were collected by non-destructive techniques. Two different approaches based on taper functions were used and adapted to predict knotty core profile, defined by stem diameter over stubs for any given height, in the pruned stem. The two models, which both included pruning intensity, explained 98 and 97 % of variability in the diameter over stubs (average root mean square error of 1.10 and 1.34 cm, respectively). An influence of pruning on stem form, evaluated through a form exponent, was found in both conifers. Higher pruning intensity resulted in stems which were significantly more cylindrical, although this effect disappeared 4 years after the intervention. These results highlight the role of pruning on timber quality, and the importance of assessing the knotty core profile and form before felling trees. © 2016 Springer-Verlag Berlin Heidelberg


Vega A.,Forest and Wood Technology Research Center | Arriaga F.,Technical University of Madrid | Guaita M.,University of Santiago de Compostela | Bano V.,Forest and Wood Technology Research Center
European Journal of Wood and Wood Products | Year: 2013

Bending strength, modulus of elasticity and density were obtained for 981 specimens of Spanish Sweet Chestnut (Castanea sativa Mill.) sawn timber from five provenances. Four-point bending tests were made with three sizes (40 × 100 × 2,500, 40 × 150 × 3,500 and 70 × 150 × 3,500 mm) according to EN 408 (CEN EN 408:2011). Visual grading criteria were established, resulting in 82 % of the samples being classified as one structural quality, namely MEF. Characteristic values of the density and the mechanical properties were determined according to EN 384 (CEN EN 384:2010a): E 0,mean = 12.3 kN mm-2; f m,k = 28 N mm -2 and ρ k = 510 kg m-3. Therefore, a strength class D24 was assigned according to EN 338 (CEN EN 338:2010b). The relationship between the modulus of elasticity and bending strength was lower (R2 = 0.26) than for Spanish coniferous species. © 2013 Springer-Verlag Berlin Heidelberg.


Bano V.,Forest and Wood Technology Research Center | Arriaga F.,Technical University of Madrid | Guaita M.,University of Santiago de Compostela
Biosystems Engineering | Year: 2013

The finite element method was used to investigate the influence of size and position of cylindrical knots on load capacity considering the elastic-plastic constitutive law of Scots pine timber. A finite element model for a four points bending test was generated considering four different knot conditions in the beams: without knot; knot as a hole; live knot and spring contact between the knot and the beam. For knots placed in the compression side, the live-knot-model best simulates real behaviour; however, when located in the tension side, the hole-model was most reliable. The bending strength of the beam, including different sizes and positions of knots, were presented in simplified diagrams and compared with clear timber strength. The results showed the influence of knots and their local grain deviation on stress distribution. The model allowed the ranking of bending strength of the beams caused by knots as a combination of three quantified indexes: tension parallel and perpendicular to the grain and shear. © 2013 IAgrE.


Cetrangolo G.,University of the Republic of Uruguay | Rodriguez S.,Forest and Wood Technology Research Center | Rodriguez A.,Forest and Wood Technology Research Center | Bano V.,University of the Republic of Uruguay
Construction and Building Materials | Year: 2015

Abstract Steel supports designed for timber structures do not always correspond with the theoretical constraints considered in the structural design. The degree of fixation provided by the supports affects the dynamic properties of structural systems. The objective of this work is to analyse the influence of different support conditions on the natural frequencies and on the damping properties of Castanea sativa Mill. timber beams. Dynamic vibration tests were performed on eight 40 × 100 × 2500 mm3 chestnut timber beams and signal processing was applied to obtain the natural frequencies and the damping ratio. Each beam was considered in three support systems: one simulating the free-free condition, and the other two were obtained by supporting them on different steel fasteners. Experimental natural frequencies were then compared to numerical values. The experimental natural frequencies did not show statistically significant differences between the two steel supports analysed. For the first flexural frequency, experimental values showed statistically significant differences with respect to the numerical results from pinned-pinned condition for the two steel supports studied. The values obtained of damping ratio were slightly higher than the values presented in the Eurocode 5 for beams with joints. © 2015 Elsevier Ltd.


Hevia A.,Forest and Wood Technology Research Center | Alvarez-Gonzalez J.G.,University of Santiago de Compostela | Majada J.,Forest and Wood Technology Research Center
Forest Ecology and Management | Year: 2016

This study examined different pruning intensities, and the subsequent tree responses, in young trees from a network of permanent plots established in two of the most important South European timber species, maritime pine (Pinus pinaster Ait.) and radiata pine (Pinus radiata D. Don), in the Atlantic region. The experimental sites were monitored for 5 years post-pruning. The results reveal a pruning effect in terms of diameter growth, but none in terms of height growth. More specifically, a significant negative effect on diameter increment was found in both species, although P. radiata was more sensitive to the treatment. Furthermore, pruning affected the dominance of some trees, and hence impacted on stand structure. Dominant and codominant trees were the social positions which performed best following pruning. Individual-tree growth models for diameter and height are reported here for both species. The models adopt an explanatory approach and incorporate tree and stand variables, pruning intensity, along with a competition index which also characterizes the social position of the tree within the stand. Silvicultural implications for selection of crop trees and quality timber production are discussed. This is a first step towards the optimisation of forest management which includes pruning, and the integration of this intervention in forest growth models for maritime and radiata pines. In general, our results provide helpful information for the management of these Atlantic conifer species focused towards producing high-quality timber, for which pruning is essential, and suggest that guidelines for this practice should consider the differences between the two species in their growing response to pruning. © 2016 Elsevier B.V..

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