Publicaciones Científicas

The wood anatomy of 132 species of the genera Abies, Cathaya, Cedrus, Keteleeria, Larix, Nothotsuga, Picea, Pinus, Pseudolarix, Pseudotsuga and Tsuga was studied to determine the elements that characterise the xylem of each genus and discuss possible groupings by wood anatomy for comparison with clades established by molecular phylogeny. [...]

After thermal modification at 210 °C using the Thermowood method, changes in Pinus radiata D. Don wood cell wall components and hygroscopicity were studied for subsequent comparison with recently felled wood of the same species in samples from the same region of provenance (Basque Country, Spain). To this end, samples were [...]

Wood anatomy is a key discipline as a tool for monitoring the global timber trade, particularly for wood listed in protected species conventions such as Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). One of the main barriers to reducing illegal trafficking of protected species is ensuring that customs officials with appropriate [...]

The hygroscopicity and thermodynamic properties of Pinus sylvestris L. wood from a coffin allegedly holding the remains of famous Spanish author Miguel de Cervantes Saavedra (1547–1616) were studied using the 15 °C and 35 °C isotherms fitted to the Guggenheim–Anderson–de Boer model and comparing them with the isotherms of recently felled wood of the same species [...]

Canary Island pine (Pinus canariensis C.Sm. ex DC) is a species endemic to the Canary Islands (Spain) that was for centuries overexploited for its wood and resin. Due to the state of the pine forest, more than 10,000 hectares were reforested in the middle of the 20th century. Now, under the silvicultural management plan, thinning operations have allowed Canary Island [...]

 A comparison was made of the hygroscopicity, cell wall chemical composition and crystallinity of recently peeled poplar (Populus spp.) wood and wood of the same species subjected to repeated cycles (20, 60 and 80) of vacuum/pressure (85 kPa/600 kPa) and soaking in an autoclave followed by oven drying. The 15 and 35 °C sorption isotherms were obtained using [...]

Changes were evaluated in cell wall components, hygroscopicity, and thermodynamic properties of Pinus sylvestris L. wood that had been in contact with salt (NaCl) for 300 years in a former saltworks storehouse in Gerri de la Sal (Lérida, Spain), comparing it with recently felled wood (new wood) of the same species [...]

Particleboard panels are normally manufactured in three layers of different sized particles of wood. One of the most important properties of particleboard is internal bond. This study determined the thickness and the physical properties of swelling, water absorption and density of 300 type P2 particleboards, as well as tensile strength perpendicular to the plane of the board [...]

The hygroscopicity and thermodynamic properties of Pinus canariensis wood buried in volcanic ash, dating from 1100 BC, were studied and compared with recently felled juvenile and mature wood of the same species. The sorption isotherms were obtained by the saturated salt method at 35 and 50 ºC. The isotherms were fitted using the Guggenheim–Anderson–de Boer model [...]

The hygroscopic properties of Pinus pinea L. wood at 35 and 50ºC were investigated by the dynamic vapour sorption (DVS) technique. The sorption kinetic behaviour was studied through the parallel exponential kinetics (PEK) model, which is subdivided into a fast and a slow process. The parameters obtained by PEK were interpreted based on the Kelvin-Voigt (KV) model to [...]

The wood structure of conifers in general and the Pinus genus in particular makes species differentiation by traditional qualitative or quantitative methods complicated or even impossible at times. Pinus sylvestris L. and Pinus nigra Arn subsp. salzmannii (Dunal) Franco are a clear example of this because they cannot be differentiated by traditional methods [...]

Several methods are available  for  obtaining  the  sorption isotherms  of  wood.  Among  these,  the  saturated  salt  and  dynamic  vapor  sorption methods  are  the most  frequently  used ones.  For the  first  time,  the  hygroscopic response  of  wood  obtained  using  these  two  methods  is  compared. This is  done  by determining  the  35 and 50 °C  adsorption  isotherms  of  juvenile [...]

Wood anatomy is one of the tools used for taxonomic classification of species. By combining this tool with molecular phylogeny, the current groupings made in morphological studies can be discussed. This study describes the wood anatomy of the monotypic genera of Cupressaceae and analyses the features that could represent synapomorphies of the principal clades recovered by molecular phylogeny [...]

The sorption isotherms of limba (Terminalia superba Engl. & Diels), obeche (Triplochiton scleroxylon K.Schum.), radiata pine (Pinus radiata D. Don) and chestnut (Castanea sativa Mill.), were plotted at 15 ºC, 35 ºC and 50 ºC. The curves were fitted using the Guggenheim-Anderson-de Boer (GAB) model. The thermodynamic properties [...]

The wood anatomy of 14 species of Cupressus was studied to determine whether there is a pattern of wood anatomical diversity between the species from the North and Central American (western) region and the Eurasian (eastern) region. Xanthocyparis vietnamensis and Chamaecyparis nootkatensis (syn. Xanthocyparis nootkatensis) were also studied to compare [...]

Pinus pinaster Aiton is the pine with the largest natural area of distribution in Spain and the species that sustains the country’s resin industry, with an annual average production of 3.2 to 3.5 kg per tree. After trees have been tapped, their wood has a high resin content and is of little use because of machining difficulties. For the first time [...]

The traditional regression method was compared with an artificial neural network for obtaining the static modulus of elasticity (MOEstatic) of Pinus radiata timber using the dynamic modulus of elasticity determined by ultrasound in the first case and ultrasonic wave propagation velocity in the second case [...]

For industrial processes, it is important to study the hygroscopicity and thermodynamic properties of juvenile and mature wood. Samples of Abies pinsapo Boiss. collected in the natural areas of the species in Spain were used to study these properties in both types of wood. The equilibrium moisture contents were obtained, and the 15, 35 and 50 ºC isotherms were plotted following [...]

The hygroscopicity and thermodynamic properties of juvenile and mature wood of Abies alba Mill. were studied through the 15, 35 and 50 °C sorption isotherms. The Guggenheim, Anderson and de Boer-Dent model was used to fit the isotherms. The thermodynamic parameters were obtained from the sorption isotherms by applying the integration method of the Clausius–Clapeyron equation [...]

 For the first time, the wood anatomy of Tetraclinis articulata (Vahl) Masters has been studied using representative samples from its natural distribution area in Spain, in Sierra de Cartagena (Region of Murcia). Mature wood was collected from five individuals representative of the forest stand and their anatomy was compared with other genera of the Cupressaceae [...]

Fossil woods of the genus Protocupressinoxylon Eckhold are reported from the Lower Cretaceous (upper Aptian e lower Albian) of Casal do Estortiga, near Santa Catarina da Serra, Lusitanian Basin, western Portugal. The three silicified specimens show up to 7-mm-thick-walled, rounded to polygonal tracheids; homogeneous rays, separated by 2 e 8 cell rows [...]

The wood anatomy of the three species of Juniperus occurring in Macaronesia is compared for the first time using representative samples of each species collected in its natural region of provenance: J. cedrus Webb & Berthel and J. phoenicea L. var. canariensis Guyot, in the Canary Islands, and J. brevifolia (Seub.) Antoine, in the Azores. The three species are anatomically similar [...]

The hygroscopicity and thermodynamic properties of Terminalia superba Engl. & Diels (limba) and Triplochiton scleroxylon K. Schum. (obeche) wood were studied and the species were compared. The 15, 35 and 50 A degrees C isotherms were plotted by applying the saturated salts method and fitted using the GAB model. The thermodynamic parameters were obtained [...]

 This study analyses the variation of main physical-mechanical properties of wood along the longitudinal and radial directions of the tree for Abies alba Mill. growing in the Spanish Pyrenees. Small clear specimens were used to study the properties of volumetric shrinkage (VS), density (.), hardness (H), bending strength (MOR), modulus of elasticity (MOE), maximum compressive strength [...]

This study provides up-to-date, representative values of the physical and mechanical properties of silver fi r wood from the Spanish Pyrenees for comparison with other provenances and timber species. Tests were conducted with clear specimens obtained throughout the tree stem and properties were determined following the UNE standards of the corresponding tests [...]

Artificial neural networks have become a powerful modeling tool. However, although they obtain an output with very good accuracy, they provide no information about the uncertainty of the network or its coverage intervals. This study describes the application of the Monte Carlo method [...]

The structural application of plywood boards has increased considerably in recent years. In this context, determining plywood mechanical properties such as bending strength and modulus of elasticity through predictive models using more-easily obtained properties is a very useful tool for in-factory quality control. Artificial neural networks have demonstrated their high capacity for [...]

Region of provenance is defined as an area with uniform ecological conditions where stands with similar phenotypic or genetic features are found. This study assesses the effect of differing climate conditions of eight Spanish regions of provenance of Pinus nigra Arn. subsp. salzmannii on earlywood anatomical traits measured in samples from basal discs from mature trees. Results showed that variation [...]

: Because of its characteristics, cork currently has no substitute in the bottle stopper industry for high quality wines and champagnes. Few studies have been conducted on water-cork relations, particularly the thermodynamic behaviour of cork. The hygroscopicity and thermodynamic properties of two cork samples of the same quality, harvested in 1968 and 2006, were studied to determine any differences in behaviour caused by the passing of time [...]

: A study was made of the hygroscopicity of two samples of cork with the same characteristics, taken from trees of the same age but with a 38- year gap between debarking. This was achieved by plotting the 35oC sorption-desorption isotherms and fitting them using the GAB model. Infrared spectra were used to determine any chemical changes in the cell wall. Extended exposure to controlled [...]

The bonding quality test is the most important of all the tests performed on plywood, as it determines the suitability of boards for use in the type of exposure they are intended for. Because this test involves aging pretreatment, results are not available in less than 24-97 h after manufacture, depending on the type of board, and therefore any error in the manufacturing process is not detected until 1-4 days later [...]

The Spanish populations of Pinus sylvestris L. occupy differentiated sites and must therefore include structural variations to cope with varied climate conditions. This study compares wood anatomical traits of P. sylvestris from ten Spanish regions of provenance with contrasting climates, taking into account the effects of region of provenance and tree nested within provenance [...]

Determining internal bond strength and thickness swelling after cyclic aging tests in humid conditions is essential in assessing the moisture resistance of particle and fiber boards. However, as operating procedures for these types of tests take at least three weeks, their use in daily finished product control is impracticable. To solve this problem an artificial neural network was used [...]

Using linear regression techniques, different regression models of the type Log10(Log10(R)+1)=a.h+b were derived to describe the relationship between the log of the electrical resistance (measured using pin electrodes) and the moisture content of two types of cork stoppers (natural [N] and agglomerate [AG]). The results obtained show that, using the models proposed [...]

 The hygroscopicity and thermodynamic properties of buried Quercus spp. wood aged 5910±250 BP were studied and compared with wood of the same genus from recently cut trees. This was done by calculating the 35ºC and 50ºC sorption isotherms and fitting them in accordance with the GAB model. The thermodynamic parameters were obtained from the isotherms using the integration method [...]

The conifer forests in the Mediterranean Arc have been subjected to overuse by humans since ancient times. Some species which took refuge in almost inaccessible places have managed to survive, but the area of other species has been greatly reduced as a result of agriculture, livestock raising, illegal felling and, in some cases, fire [...]

A study was conducted on the variation in growth, biomass, juvenile wood anatomy and needle morphology of Pinus halepensis Mill. from three Spanish regions of provenance characterized by environmental differences, without the influence of the site factor. Seeds collected from two progenies in each region were planted in a single plot and the trees were felled [...]

Determining the modulus of elasticity of wood by applying an artificial neural network using the physical properties and non-destructive testing can be a useful method in assessments of the timber structure in old constructions. The modulus of elasticity of Abies pinsapo Boiss. timber was predicted in this study through the parameters of density, width, thickness, moisture content, ultrasonic wave propagation [...]

The hygroscopicity and thermodynamic properties of buried juvenile Pinus sylvestris L. wood with an age of 1170±40 BP were compared with the corresponding values of juvenile wood of the same species from recently cut trees. The 35ºC and 50ºC isotherms were plotted following the saturated salts method and subsequently fitted in accordance with the GAB model. The isotherms were [...]

The mechanical properties of Abies pinsapo Boiss., a relict species from the south of Spain, have been studied very little due to the high level of protection that applies this species. Forest fire prevention measures have enabled the species to be characterized for the first time, including a comparison of its three regions of provenance [...]

An analysis was made of the wood anatomy of seven species, one subspecies and two varieties of the genus Abies from the Mediterranean area (A. alba, A. borisii-regis, A. cephalonica, A. cilicica, A. nordmanniana, A. nordmanniana subsp. equi-trojani, A. numidica, A. pinsapo, A. pinsapo var. marocana and A. pinsapo var. tazaotana) in order to find phyletically relevant [...]

The literature on the wood anatomy of the genus Abies is reviewed and discussed, and complemented with a detailed study of 33 species, 1 subspecies and 4 varieties. In general, the species studied do not show diagnostic interspecific differences, although it is possible to establish differences between groups of species using the biometry and certain qualitative features [...]

Artificial neural networks are an efficient tool for modelling production control processes using data from the actual production as well as simulated or design of experiments data. In this study two artificial neural networks were combined with the control process charts and it was checked whether the data obtained by the networks were valid for variable process control in particleboard manufacture [...]

The main objective of this study was to identify differential anatomical features between Ulmus pumila L. and Ulmus minor Mill. clones resistant to Dutch elm disease and U. minor clones susceptible to Dutch elm disease, with a focus on the intervascular pits and medullary rays. Resistant elms showed lower mean values than susceptible elms for pit membrane diameter, pit aperture area [...]

This study, which includes 51 species and six genera of subfamily Abietoideae (Pinaceae), assesses the systematic significance of the wood structure within this group. In particular, the presence of normal and traumatic resin canals, the ray structure and the axial parenchyma constitute phylogenetically informative features. Comparative wood anatomy of Abietoideae [...]

Neural networks are complex mathematical structures inspired on biological neural networks, capable of learning from examples (training group) and extrapolating knowledge to an unknown sample (testing group). The similarity of wood structure in many species, particularly in the case of conifers, means that they cannot be differentiated using traditional methods [...]

The hygroscopicity and thermodynamic properties of juvenile Pinus sylvestris L. wood taken from the submerged piles of a bridge built in 1903 over the Jiloca River, in Spain, were compared with the corresponding values of juvenile wood of the same species from recently cut trees. The 35 degrees C and 50 degrees C isotherms were plotted and subsequently fitted [...]

The physical properties (specific gravity, moisture content, thickness swelling and water absorption) and mechanical properties (internal bond strength, bending strength and modulus of elasticity) were determined on 93 Spanish-manufactured standard particleboards of different thicknesses selected randomly at the end of the production process. The testing methods of the corresponding European standards [...]

Abstract: The sorption and desorption isotherms of standard particleboard were obtained in this study using the equilibrium moisture contents achieved by applying the gravimetric method of saturated salts at 35 degrees C and 50 degrees C in the water activity range of 0.11 to 0.89. The curves were fitted following the Guggenheim, Anderson and Boer-Dent model, […]

The mechanical properties and characteristic values of radiata pine plywood for structural use were measured using the European standards (EN 789 and EN 1058). Eight different compositions of panels with thicknesses from 9 to 30 mm were tested. Their mechanical properties were found to be similar to those of other plywoods from Europe manufactured with spruce. The test results of plywood [...]

The response of the wood of Pinus sylvestris L. to impact bending using the Charpy method was studied in 2940 defect-free, oriented test pieces from the central board of 10 trees felled during scheduled cutting, with the values obtained being related to the position of the test piece in the tree, both from the pith to the outside and in terms of its height in the tree [...]

The 35 degrees and 50 degrees C isotherms of juvenile Pinus sylvestris L. wood from recently cut trees were compared with those of juvenile wood of the same species previously forming part of an 18(th) century wooden building in order to determine the thermodynamic properties of the two types of wood through the isotherms. The isotherms were plotted using the gravimetric method of saturated salts [...]

This study describes the structure of the wood of Abies pinsapo from samples taken from its three natural distribution areas in the Iberian Peninsula (Sierra de Grazalema, Sierra de las Nieves and Sierra Bermeja) and compares them with the varieties from the north of Africa, Abies pinsapo var. marocana from the Talassemtane mountains and A. pinsapo var. tazaotana from the Tazaout mountains [...]

Abstract: In view of the unique nature of the discovery, this article is an account of the three botanical expeditions made to the natural enclaves of Abies pinsapo Boiss., firstly by the Swiss botanist Edmond Boissier in 1837, then by the Spanish forestry engineers Luis Ceballos Fernández de Córdoba and Manuel Martín Bolaños in 1928, and later by […]

● DOI: Abstract: The position of the Iberian Peninsula during the Early Cretaceous, sandwiched between Laurasia and Gondwana, makes it an important area for the biogeography study of terrestrial ecosystems. Relevant data are, however, scarce. The discovery of silicified wood in the west of the Cameros Basin, in the village Hacinas (Spain), is the […]

Abstract: Through this work, the technical and industrial viability of the use of the wood of quebracho blanco (Aspidosperma quebracho-blanco Schlecht.) in the making of oriented strandboard (OSB) panels was studied. Due to the high density of this wood, a mixture was made using strands of loblolly pine (Pinus taeda L.), whose low density allows panels with […]

The hygroscopic response of the juvenile wood of Pinus sylvestris L. from recently cut trees from the Valsain Forest in Segovia, Spain (new wood) was compared to that of the juvenile wood of the same species used in roof rafters installed at the end of the eighteenth century (old wood), which came from the same forest. The 35 degrees C isotherms were plotted using the saturated salts method [...]

Pinus canariensis (Canary Island Pine or Pitch Pine) forms natural forests on the islands of Tenerife and La Palma. The heartwood has an extraordinarily high resin content, and this paper provides an anatomical description of the wood as well as an interpretation of the factors relating to this resinification. Pinus canariensis possesses many subsidiary parenchyma cells surrounding the axial resin canals [...]

The reduction of wood response to variations of ambient humidity, described as kind of ageing, has been studied from both points of view of moisture uptake and dimensional changes. Clearwood specimens from 3 gymnosperms (Pinus sylvestris L., Pinus pinaster Ait., Pinus insignis Douglas) and 4 angiosperms [...]

Following the traditional methods of preparation and description of wood at microscopy level, 352 descriptions of the woods of conifers were made. For the characterisation of each wood a multiple entry key was prepared, with a total of 81 features divided into four groups: tracheids with 29 features, axial parenchyma with 8, wood rays with 37 and resin canals with 7.

The saturated salts method was used in this study to quantify hysteresis in Pinus sylvestris L. wood, in an exercise that involved plotting the 35 degrees C desorption and sorption isotherms. Nine salts were used, all of which establish stable and known relative humidity values when saturated in water. The wood was kept at the relative humidity generated by each of these [...]

t: Este trabajo representa el primer paso para la obtención de una clave de identificación de múltiple entrada para maderas de coníferas de todo el mundo a nivel de especie. Se ha realizado la identificación de 120 coníferas de América del Norte y Europa. Los métodos utilizados son los tradicionales de preparación y descripción microscópica de maderas [...]

Este artículo resume la línea de investigación seguida para demostrar y evaluar el fenómeno físico de fatiga higroscópica y dimensional de la madera. Para ello se ha recurrido a la construcción de isotermas de 20ºC y al establecimiento de unos coeficientes de envejecimiento para evaluar dicho proceso.