Earlywood vessel features in Quercus faginea: relationship between ring width and wood density at two sites in Portugal

Wood anatomy holds relevant information for tree development and timber quality (e.g., wood density), which is important for the sustainability of the species. Quercus faginea Lam. (Portuguese or Lusitanian oak) is an autochthonous Mediterranean oak species characterized by a shrinking natural distribution area and use abandonment. We studied the variation of several wood properties and their relationships with the aim of determining and possibly increasing the wood economic value of this species. The anatomical features of earlywood vessels (area, number, frequency and proportion) were investigated in twenty Q. faginea trees sampled at two locations within the natural distribution of the species in Portugal. Moreover, we analyzed the variation of vessel features from pith to bark, the radial growth and the wood density to search for patterns and relationships among the analyzed parameters. Mean earlywood vessel area increased with cambial age up to 60-70 years and then leveled off. An inverse pattern was found for the number of vessels per ring beyond that age. Similar radial patterns of all vessel features were found at both sites, and no significant differences in earlywood vessel area were found between sites. The within-tree development of earlywood vessels was age-related, though not influenced by growth. Earlywood vessel features explained the variation of wood density, i.e., wood density of Q. faginea was strongly negatively correlated with both mean vessel area and proportioninfo:eu-repo/semantics/publishedVersio

Chemical characterization and extractives composition of heartwood and sapwood from Quercus faginea

Research ArticleHeartwood and sapwood of Quercus faginea were evaluated in relation to summative chemical composition and non-polar and polar extracts composition, including an assessment of antioxidant properties (DPPH and FRAP). Twenty trees from two sites in Portugal were analysed. Heartwood had approximately two times more solvent extractible compounds than sapwood (on average 19.0% and 9.5%). The lipophilic extractible compounds were below 1%, and most of them were polar e.g. ethanol-soluble compounds corresponded to 65% of total extractives in heartwood and 43% in sapwood. Lignin content was similar in sapwood and heartwood (28.1% and 28.6% of extractive-free wood respectively) as well as the sugar composition. Site did not influence the chemical composition. The lipophilic extractible compounds from both sapwood and heartwood included mainly saturated fatty acids (23.0% and 36.9% respectively) and aromatic compounds were also abundant in sapwood (22.9%). The ethanol-water extractibles had a high content of phenolic substances (558.0 and 319.4 mg GAE/g extract, respectively of heartwood and sapwood). The polyphenolic composition was similar in heartwood and sapwood with higher content of ellagitannins (168.9 and 153.5 mg tannic acid/g of extract in sapwood and heartwood respectively) and very low content of condensed tannins. The antioxidant activity was very high with IC50 of 2.6 μg/ml and 3.3 μg/ml for sapwood and heartwood respectively, as compared to standard antioxidants (IC50 of 3.8 μg/ml for Trolox). The ferric reducing ability was 2.8 and 2.0 mMol Trolox equivalents/ g extract of heartwood and sapwood respectively. The variability between trees was low and no differences between the two sites were found. Q. faginea showed a very good potential for cooperage and other applications for which a source of compounds with antioxidant properties is desirableinfo:eu-repo/semantics/publishedVersio

An Integrated Similarity Analysis of Anatomical and Physical Wood Properties of Tropical Species from India, Mozambique, and East Timor

Tropical species are highly valued timber sources showing a large diversity of wood characteristics. Since there are major concerns regarding the sustainability of these tropical species in many tropical regions, knowledge of the variability in wood properties is therefore a valuable tool to design targeted exploitation and to enlarge the wood resources base, namely by identifying alternatives for CITES-listed species. In this study, 98 tropical wood species belonging to 73 genera from India, Mozambique, and East Timor were investigated regarding wood anatomy and physical properties. Numerical taxonomy, by means of cluster analysis and principal component analysis grouped species with anatomical and physical similarities from different geographical origins. In addition to wood density, ray and vessel characteristics as well as wood moisture and wood shrinkage properties explained the main variability of these species. The contribution of wood color patterns was highlighted as consistently separating the Mozambique woods. A distinct geographical pattern was not observed, reinforcing that species from India, Mozambique, and East Timor show similar anatomical and physical wood properties, which could be useful to increase timber trade diversity. The multivariate analysis showed that species from Mozambique, such as Morus mesozygia, and Millettia stuhlmannii and Swartzia madagascariensis, could be alternatives for the CITES-listed species Cedrela odorata and Dalbergia melanoxylon, respectivelyinfo:eu-repo/semantics/publishedVersio

Estrutura e caracterização anatómica da madeira de carvalho português (Quercus faginea Lam.)

Apresenta-se um estudo sobre a madeira de carvalho-português (Quercus faginea Lam.), uma das mais importantes espécies de carvalho autóctones do nosso território. Este trabalho está integrado num projecto de investigação cujo principal objectivo é identificar novos usos de qualidade para a madeira de carvalho-português. Seleccionaram-se e abateram-se 10 árvores, com idades entre 34 e 60 anos, no Nordeste Transmontano, e recolheram-se rodelas a 1,30 m de altura. Estudou-se para cinco árvores a variação radial na árvore e entre árvores das dimensões das fibras, raios e vasos. A madeira apresenta porosidade em anel, normalmente com camadas de crescimento bem distintas e vasos solitários orientados radialmente. O padrão de variação radial das fibras caracterizou-se por um aumento de comprimento da medula para a periferia, variando em média de 995 a 1195 m, enquanto a espessura se manteve relativamente constante. Os diâmetros dos vasos aumentaram da medula para a periferia, em média de 170 a 208 m. O parênquima radial inclui raios unisseriados, em média com 10 células em média, e raios multisseriados, com máximos de 21 mm de comprimento e 0,8 mm de largura

Chemical composition of barks from Quercus faginea trees and characterization of their lipophilic and polar extracts

The bark from Quercus faginea mature trees from two sites was chemically characterized for the first time. The barks showed the following composition: ash 14.6%, total extractives 13.2%, suberin 2.9% and lignin 28.2%. The polysaccharides were composed mainly of glucose and xylose (50.3% and 35.1% of all monosaccharides respectively) with 4.8% of uronic acids. The suberin composition was: ω-hydroxyacids 46.3% of total compounds, ɑ,ω-alkanoic diacids 22.3%, alkanoic acids 5.9%, alkanols 6.7% and aromatics 6.9% (ferulic acid 4.0%). Polar extracts (ethanol-water) had a high phenolic content of 630.3 mg of gallic acid equivalents (GAE)/g of extract, condensed tannins 220.7 mg of catechin equivalents (CE)/g extract, and flavonoids 207.7 mg CE/g of extract. The antioxidant activity was very high corresponding to 1567 mg Trolox equivalents/g of extract, and an IC50 of 2.63 μg extract/ml. The lipophilic extracts were constituted mainly by glycerol and its derivatives (12.3% of all compounds), alkanoic acids (27.8%), sterols (11.5%) and triterpenes (17.8%). In view of an integrated valorization, Quercus faginea barks are interesting sources of polar compounds including phenols and polyphenols with possible interesting bioactivities, while the sterols and triterpenes contained in the lipophilic extracts are also valuable bioactive compounds or chemical intermediates for specific high-value market niches, such as cosmetics, pharmaceuticals and biomedicineinfo:eu-repo/semantics/publishedVersio

Wood density and ring width in Quercus rotundifolia trees in southern Portugal

Quercus rotundifolia Lam., known as holm oak or evergreen oak, occurs naturally in the western Mediterranean region, mainly as part of the agroforestry or agrosilvopastoral systems in Portugal (“montado”) and Spain (“dehesa”), and is economically important for acorn production. Less attention has been given to Q. rotundifolia wood, and its density variability is not known, namely related to tree growth. The wood density of 20 Q. rotundifolia trees was measured along the radial direction by X-ray densitometry and the factors responsible for ring width and wood density variation within and between trees were investigated at two sites located within the main species region in southern Portugal. Ring width was significantly different between sites, with an average of 1.81 mm and 1.55 mm. Wood density was very high and averaged between 888 kg/m3 and 914 kg/m3 but not significantly different between sites. Ring width and wood density showed a positive and significant correlation at both sites. Cambial age was the main source of variation for ring width and wood density, while between-tree effects accounted for a considerable proportion of wood density variation. The results are an important contribution for the species valorisation aiming at high-value wood products, also adding knowledge on the species growth of interest for tree selection and sustainable managementinfo:eu-repo/semantics/publishedVersio

Quercus rotundifolia bark as a source of polar extracts: structural and chemical characterization

Quercus rotundifolia bark was studied regarding anatomical, chemical, and antioxidant properties from trees in two sites in southern Portugal and are here reported for the first time. The general structure and anatomy of Q. rotundifolia bark showed a rhytidome with sequential undulated and anastomosed periderms with a small proportion of cork, while the phloem included broad rays with strong cell sclerification, groups of sclereids with embed large prismatic crystals, and abundant druses in parenchyma cells. The mean chemical composition was 15.5% ash, 1.6% dichloromethane extractives, 6.4% ethanol and 9.3% water extractives, 3.0% suberin, 30.5% total lignin, and 33.8% carbohydrates. Carbohydrates included mainly glucose (50.7% of total monomers) and xylose (23.8%), with uronic (3.0%) and acetic acids (1.0%). Suberin was mainly composed of !-hydroxyacids (48.0% of all compounds) and ,!-diacids (19.5%). The main compounds found in the lipophilic extracts were triterpenes (43.6%–56.2% of all compounds) and alkanoic acids (32.7%–41.7%). Phenolic content was high especially in the ethanol extracts, ranging from 219.5–572.9 mg GAE/g extract and comprising 162.5–247.5 CE/g extract of flavonoids and 41.2–294.1 CE/g extract of condensed tannins. The extracts revealed very good antioxidant properties with IC50 values of 4.4 g ethanol extract/mL and 4.7 g water extract/mL. Similar anatomical, chemical, and antioxidant characteristics were found in the bark from both sites. The high phenolic content and excellent antioxidant characteristics of polar extracts showed holm oak barks to be a promising natural source of antioxidants with possible use in industry and pharmaceutical/medical areasinfo:eu-repo/semantics/publishedVersio

Avaliação de algumas propriedades físicas da madeira de sobreiro (Quercus suber L.) tendo em vista o seu potencial impacto tecnológico

Congresso Florestal Nacional: A floresta e as gentes - Actas das ComunicaçõesApresenta-se um estudo de caracterização e variação de propriedades físicas da madeira da Quercus suber L. tendo em vista a sua potencial utilização para o fabrico de peças de madeira de qualidade elevada. Foram analisadas as seguintes propriedades da madeira de sobreiro e a sua variação para diferentes temperaturas e humidades relativas do ar: teor de humidade de equilíbrio, densidade e variação dimensional. O estudo foi feito na madeira de 5 árvores adultas já sujeitas a descortiçamento. As temperaturas estudadas tipificaram um ambiente interior não climatizado no inverno (15ºC), no verão (27ºC) e um ambiente climatizado (22ºC) e a variação de humidade relativa estudado foi de 10% a 80%. Verificou-se uma variação da retracção volumétrica total entre 14,3–15,2 % e do coeficiente de retracção volumétrica entre 0,49–0,56%. A retracção linear radial e tangencial variou, respectivamente entre 3,5–3,7% e 9,1–9,8%. Para a anisotropia obtiveram-se valores entre 2,4–2,7. Os valores da densidade a 12% de humidade variaram entre 0,63–0,64 g/cm3 e a higroscopicidade obtida foi de 0,003. Observaram-se diferenças pouco significativas para a variação das dimensões, teor de água e densidade da madeira entre as 3 temperaturas utilizadas nos ensaios físicos. A classificação tecnológica da madeira de sobreiro em relação às propriedades estudadas é a seguinte: madeira moderadamente pesada, medianamente nervosa, retráctil (com retractibilidade radial fraca e tangencial média), anisotropia alta, teor de saturação das fibras alto e higroscopicidade média

Variabilidade anatómica da teca (Tectona grandis) de Timor-Leste

A teca (Tectona grandis) é uma importante espécie indígena do sudeste asiático, produtora de madeira nobre com excelente qualidade e grande procura no mercado mundial pela sua resistência, durabilidade e beleza. Estas propriedades dependem, entre outras, da estrutura e variabilidade da madeira, na espécie, entre árvores e na árvore consoante as condições ambientais. Não existem estudos publicados sobre a variabilidade anatómica da madeira para a teca proveniente de Timor-Leste. O estudo incidiu em três árvores, em amostras retiradas a três níveis de altura total e da medula para a periferia da árvore. Realizaram-se observações à lupa e ao microscópio e foram determinados: n.º e área de vasos por anel de crescimento, comprimento, largura e espessura da parede de fibras, utilizando um sistema de análise de imagem. Os resultados indicam que da base para o topo da árvore houve um aumento do número médio e um decréscimo da área média de vasos por anel de crescimento, do comprimento e largura média das fibras. Radialmente, da medula para a periferia, diminuiu o número e aumentou a área média de vasos por anel de crescimento, o comprimento, a largura e a espessura da parede das fibras

Caracterização da composição química da madeira de Quercus faginea

Neste estudo fez-se a caracterização da composição química somativa (cinzas, extractivos, lenhinas e polissacáridos) da madeira de cerne e de borne de Quercus faginea proveniente de um local do Nordeste Transmontano (Macedo de Cavaleiros). Foram seleccionadas e abatidas 10 árvores de Quercus faginea e retiradas amostras de discos a 1,30 m de altura da árvore. As árvores de Quercus faginea estudadas apresentaram todas formação de cerne, com um contorno regular e cor castanha amarelada bem distinto do borne de cor castanha mais clara. A área de cerne variou entre 15% e 64% da área total da secção transversal da madeira, e a espessura de borne entre 1,5 e 4,9 cm. A madeira de Quercus faginea apresentou a seguinte composição química: cinzas 0,8%, extractivos totais 14,5% e lenhina total 24,5%. Os polissacáridos são constituídos principalmente por glucose e xilose (respectivamente em média 59,5% e 31,0% dos monómeros)