| evolution of phenolic compounds of spanish oak wood during natural seasoning. first results. | low molecular weight polyphenols and ellagitannins were analyzed by hplc, and the molecular weight distribution of ellagitannins was calculated by gpc, in oak heartwood of quercus robur l., quercus petraea liebl., quercus pyrenaica wild., and quercus faginea lam., grown in spain, before and after 1 year of seasoning, in bordeaux, france. during this process, the concentrations of low molecular weight polyphenols (acids and aldehydes, benzoic and cinnamic, and coumarins) increased, and those of e ... | 1999 | 10564039 |
| changes in low molecular weight phenolic compounds in spanish, french, and american oak woods during natural seasoning and toasting. | the evolution of low molecular weight polyphenols in spanish oak heartwood of quercus robur,quercus petraea, quercus pyrenaica, and quercus faginea was studied by hplc, in relation to the processing of wood in barrel cooperage. the polyphenolic composition of spanish woods subjected to natural seasoning for 3 years and to the toasting process was studied in relation to those of french oak of q. robur (limousin) and q. petraea (allier) and american oak of q. alba (missouri), which are habitually ... | 2001 | 11308327 |
| evolution of ellagitannins in spanish, french, and american oak woods during natural seasoning and toasting. | the evolution of tannins in spanish oak heartwood of quercus robur l., quercus petraea liebl.,quercus pyrenaica wild., and quercus faginea lam. was studied in relation to the processing of wood in barrel cooperage. their evolution was compared with that of french oak of q. robur (limousin, france) and q. petraea (allier, france) and american oak of quercus alba l. (missouri), which are habitually used in cooperage. two stages of process were researched: the seasoning of woods during 3 years in n ... | 2001 | 11513647 |
| phenological behaviour of quercus in ourense (nw spain) and its relationship with the atmospheric pollen season. | knowing the beginning of the pollen season is of particular importance to people allergic to a given pollen. phenological studies in combination with aerobiological studies enable us to observe the relationship between the reproductive phenology of the species and their airborne pollen curves. they also enable us to study the relationship between the release of pollen from anthers and its presence in the atmosphere. the objectives of this study are (1) to determine chill and heat requirements fo ... | 2002 | 12242473 |
| volatile compounds in spanish, french, and american oak woods after natural seasoning and toasting. | the volatile composition (volatile phenols, phenolic aldehydes, furanic compounds, lactones, phenyl ketones, and other related compounds) of spanish oak heartwood of quercus robur, quercus petraea,quercus pyrenaica, and quercus faginea was studied by gas chromatography/mass spectrometry, in relation to the processing in barrels cooperage and in relation to the french oak of quercus robur (limousin) and quercus petraea (allier) and american oak of quercus alba (missouri), which are habitually use ... | 2003 | 13129296 |
| volatile compounds in a spanish red wine aged in barrels made of spanish, french, and american oak wood. | a red rioja wine was aged in barrels made of spanish oak wood (quercus robur, quercus petraea,quercus pyrenaica, and quercus faginea) during 21 months. the concentrations of some volatile compounds [syringaldehyde, vanillin, eugenol, maltol, guaiacol, 4-ethylphenol, cis and trans isomers of beta-methyl-gamma-octalactone, 2-furfuraldehyde, 5-methyl-2-furfuraldehyde, 5-(hydroxymethyl)-2-furfuraldehyde, and furfuryl alcohol] were studied in these wines and compared with those of the same wine aged ... | 2003 | 14664527 |
| analysis of serpentinophytes from north-east of portugal for trace metal accumulation--relevance to the management of mine environment. | in north-east of portugal, the serpentinized area is about 8000 ha with a characteristic geology and flora. the serpentine plant community and respective soils were analyzed to examine the trace metal budget in different tissues of the plants exhibiting resistance to trace metals. one hundred and thirty five plant species belonging to 39 families and respective soils have been analyzed for total co, cr, cu, fe, mn, ni, pb and zn. substantial amounts of ni, cr, co and mn were detected in plant ti ... | 2004 | 14675842 |
| leaf water potential and stomatal conductance in quercus pyrenaica willd. forests: vertical gradients and response to environmental factors. | two permanent sampling sites were selected at the two extremes of a rainfall gradient in natural forests of quercus pyrenaica willd. located in the sierra de gata (salamanca province, spain). during 1991 and 1992, diurnal courses of transpiration rate (e), stomatal conductance (g(s)) and leaf water potential (psi(l)) were studied at different levels in the tree canopy. leaf water potential fell from a high value in the early morning to a minimum at midday and then increased again in the afternoo ... | 1994 | 14967668 |
| gene flow and hybridisation in a mixed oak forest (quercus pyrenaica willd. and quercus petraea (matts.) liebl.) in central spain. | oaks are long-standing models for the study of gene flow and hybridisation. temperate (quercus petraea) and sub-mediterranean (quercus pyrenaica) oaks coexist in central spain, showing remarkable differences in population size and structure. q. petraea has a scattered distribution in central spain, where it is at one of the southernmost limits of its range, and forms low-density stands; in contrast, q. pyrenaica is widespread in the region. we selected a mixed population of the two species ( app ... | 2005 | 16249802 |
| differential light responses of mediterranean tree saplings: linking ecophysiology with regeneration niche in four co-occurring species. | the ecophysiological mechanisms underlying plant-plant interactions and forest regeneration processes in mediterranean ecosystems are poorly understood, and the experimental evidence for the role of light availability in these processes is particularly scant. we analyzed the effects of high and low irradiances on 31 ecological, morphological and physiological variables in saplings of four late-successional mediterranean trees, two deciduous (acer opalus subsp. granatense (boiss.) font quer & rot ... | 2006 | 16585040 |
| functional traits and plasticity in response to light in seedlings of four iberian forest tree species. | we investigated the differential roles of physiological and morphological features on seedling survivorship along an experimental irradiance gradient in four dominant species of cool temperate-mediterranean forests (quercus robur l., quercus pyrenaica willd., pinus sylvestris l. and pinus pinaster ait.). the lowest photochemical efficiency (f(v)/f(m) in dark-adapted leaves) was reached in deep shade (1% of full sunlight) in all species except q. robur, which had the lowest photochemical efficien ... | 2006 | 16877327 |
| chemical characterization of oak heartwood from spanish forests of quercus pyrenaica (wild.). ellagitannins, low molecular weight phenolic, and volatile compounds. | the need for new sources of quality wood supply for cooperage has led to looking into the possibility of utilizing quercus pyrenaica wild. oak, a species native to the iberian peninsula, as an alternative to other european (quercus robur and qurecus petraea) and american (quercus alba) oaks. the low molecular weight phenolic composition, ellagitannins, and volatile compounds (including a wide range of compound families such as volatile phenols, furanic compounds, lactones, phenyl ketones, other ... | 2006 | 17032045 |
| soil phosphorus forms as quality indicators of soils under different vegetation covers. | the type of vegetation cover determines the physicochemical and biological properties of the soil over which they are developing. the objective of this study was to determine the effect of different vegetation covers on the forms of soil phosphorus, in order to know which of these forms can be used as a soil quality indicator. the experimental area was located on the acidic plateau at the north of palencia (north spain), where an area was selected vegetation covers very close to each other: pine ... | 2007 | 17307240 |
| fine-scale spatial genetic structure in mixed oak stands with different levels of hybridization. | oaks are model species for the study of natural introgressive hybridization. high interfertility among oak taxa might result in collective evolution, through transpecific spread of advantageous alleles, challenging the standard concept of species. nine highly polymorphic microsatellite (nussr) loci were analysed in three mixed oak populations of quercus pyrenaica and quercus petraea (montejo, somosierra and robregordo) with different density and hybridization rates. both leaf morphology and mole ... | 2007 | 17391407 |
| soil co2 efflux in a mixed pine-oak forest in valsaín (central spain). | soil-surface co2 efflux and its spatial and temporal variation were investigated in a southern mediterranean, mixed pine-oak forest ecosystem on the northern slopes of the sierra de guadarrama in spain from february 2006 to july 2006. measurements of soil co2 efflux, soil temperatures, and moisture were conducted in nine 1963-m2 sampling plots distributed in a gradient around the ecotone between pinus sylvestris l. and quercus pyrenaica lam. forest stands. total soil organic matter, walkey-black ... | 2007 | 17450294 |
| leaf physiological versus morphological acclimation to high-light exposure at different stages of foliar development in oak. | we investigated light acclimation in seedlings of the temperate oak quercus petraea (matt.) liebl. and the co-occurring sub-mediterranean oak quercus pyrenaica willd. seedlings were raised in a greenhouse for 1 year in either 70 (hl) or 5.3% (ll) of ambient irradiance of full sunlight, and, in the following year, subsets of the ll-grown seedlings were transferred to hl either before leaf flushing (ll-hlbf plants) or after full leaf expansion (ll-hlaf plants). gas exchange, chlorophyll a fluoresc ... | 2008 | 18316308 |
| volatile compounds and sensorial characterization of wines from four spanish denominations of origin, aged in spanish rebollo (quercus pyrenaica willd.) oak wood barrels. | the evolution of almost 40 oak-related volatile compounds and the sensorial characteristics of red wines from four spanish denominations of origin (dos) (bierzo, toro, ribera de duero, and rioja) during aging in barrels made of rebollo oak wood, quercus pyrenaica, were studied and compared to the same wines aged in american and french oak barrels. each oak wood added unique and special characteristics to the wine, and in addition, each wine showed a different ability to extract the compounds, wh ... | 2008 | 18778067 |
| volatile compounds in acacia, chestnut, cherry, ash, and oak woods, with a view to their use in cooperage. | extracts of wood from acacia, european ash, american ash, chestnut, cherry, and three oak species (quercus pyrenaica, quercus alba and quercus petraea) before and after toasting in cooperage were studied by gc-ms. 110 compounds were detected, and 97 of them were identified. in general, all studied woods showed more lignin derivatives than lipid and carbohydrate derivatives, with a higher variety of compounds detected and abundance of them. the toasting led to an increase in the concentrations of ... | 2009 | 19290598 |
| volatile compounds of red wines macerated with spanish, american, and french oak chips. | the volatile composition of a red wine aged for 2 months with three different spanish oak chips (quercus pyrenaica and quercus petraea) from different regions of castilla y león was compared with that of wines aged with american and french chips. in general, the extraction kinetics showed that the maximum concentration of the volatile compounds extracted from wood can be reached in only 1 month. in the final wines, the levels of furanic aldehydes and eugenol were higher in the wines macerated wi ... | 2009 | 19601669 |
| effect of size, seasoning and toasting in the volatile compounds in toasted oak wood and in a red wine treated with them. | the increasing demand for wood for barrel-making in addition to the rapid extension of alternative aging system, have led to looking into the possibility of utilizing spanish oak. quercus pyrenaica is the species that predominates in spain, and the chemical composition of its heartwood (ellagitannins, low molecular weight phenolic and volatile compounds) and its incidence in characteristics of wine are similar to that of other species that are of recognized oenological quality for barrel-making, ... | 2010 | 20103165 |
| flash-flood impacts cause changes in wood anatomy of alnus glutinosa, fraxinus angustifolia and quercus pyrenaica. | flash floods may influence the development of trees growing on channel bars and floodplains. in this study, we analyze and quantify anatomical reactions to wounding in diffuse-porous (alnus glutinosa l.) and ring-porous (fraxinus angustifolia vahl. and quercus pyrenaica willd.) trees in a mediterranean environment. a total of 54 cross-sections and wedges were collected from trees that had been injured by past flash floods. from each of the samples, micro-sections were prepared at a tangential di ... | 2010 | 20462937 |
| characterization of volatile constituents in commercial oak wood chips. | the volatile composition of the different oak wood pieces (chips of quercus spp.) that can be found on the market to be used as alternatives to barrels for aging wines, as well as of chips of quercus pyrenaica which are being introduced, was studied, evaluating the contents of volatile phenols, lactones, furanic compounds, pyranones, phenolic aldehydes, phenolic ketones, and others. in regard to the overall results, the volatile composition of these products varies widely and has not been clearl ... | 2010 | 20687559 |
| oak leaf (quercus pyrenaica) poisoning in cattle. | three experiments were conducted to study the clinical and pathological findings associated with poisoning in cattle due to ingestion of young oak leaves (ol) and the main factors responsible for toxicosis. in experiment 1, six 1.4year-old bulls were fed up to 5kg of young ol per animal per day and showed no signs of toxicity, apart from a slight proteinuria. in experiment 2, another six 1.4year-old bulls were first subjected to severe feed restriction for eight days and then fed a higher amount ... | 2011 | 21306752 |
| fragment quality and matrix affect epiphytic performance in a mediterranean forest landscape. | destruction and fragmentation of habitats represent one of the most important threats for biodiversity. here, we examined the effects of fragmentation in mediterranean forests on the epiphytic lichen lobaria pulmonaria (lobariaceae). we tested the hypothesis that not only the level of fragmentation affects l. pulmonaria populations, but also the quality of the habitat and the nature of the surrounding matrix affect them. the presence and abundance of the lichen was recorded on 2039 trees in a to ... | 2009 | 21622317 |
| establishment success of coexisting native and exotic trees under an experimental gradient of irradiance and soil moisture. | the exotic trees ailanthus altissima, robinia pseudoacacia, acer negundo and elaeagnus angustifolia coexist with the native trees fraxinus angustifolia and ulmus minor in river banks of central spain. similarly, the exotic trees acacia dealbata and eucalyptus globulus co-occur with the natives quercus pyrenaica and pinus pinaster in northwest spain. we aimed to identify the environmental conditions that favour or hamper the establishment success of these species. in spring 2008, seeds of the stu ... | 2011 | 21842417 |
| Effect of the administration of young leaves of Quercus pyrenaica on rumen fermentation in relation to oak tannin toxicosis in cattle. | Three experiments were conducted to study the effect of the administration of young leaves of Quercus pyrenaica (OL) on in vivo ruminal fermentation in relation to oak tannin toxicosis in cattle. In Experiment 1, six bulls were fed up to 5 kg fresh matter (FM) of OL per animal and day for 14 days. In Experiment 2, another six bulls were first subjected to severe feed restriction for 8 days and then fed a higher amount of OL (approximately 10 kg FM daily) for 3 days. In Experiment 3, three bulls ... | 2011 | 21992033 |
| stem co2 efflux in six co-occurring tree species: underlying factors and ecological implications. | stem respiration plays a role in species coexistence and forest dynamics. here we examined the intra- and inter-specific variability of stem co2 efflux (e) in dominant and suppressed trees of six deciduous species in a mixed forest stand: fagus sylvatica l., quercus petraea [matt.] liebl, quercus pyrenaica willd., prunus avium l., sorbus aucuparia l. and crataegus monogyna jacq. we conducted measurements in late autumn. within species, dominants had higher e per unit stem surface area (es ) main ... | 2015 | 25292455 |