Branch Wood Research Articles

Does physiological acclimation to climate warming stabilize the ratio of canopy respiration to photosynthesis?

Given the contrasting short-term temperature dependences of gross primary production (GPP) and autotrophic respiration, the fraction of GPP respired by trees is predicted to increase with warming, providing a positive feedback to climate change. However, physiological acclimation may dampen or eliminate this response. We measured the fluxes of aboveground respiration (Ra ), GPP and their ratio (Ra /GPP) in large, field-grown Eucalyptus tereticornis trees exposed to ambient or warmed air temperatures (+3°C). We report continuous measurements of whole-canopy CO2 exchange, direct temperature response curves of leaf and canopy respiration, leaf and branch wood respiration, and diurnal photosynthetic measurements. Warming reduced photosynthesis, whereas physiological acclimation prevented a coincident increase in Ra . Ambient and warmed trees had a common nonlinear relationship between the fraction of GPP that was respired above ground (Ra /GPP) and the mean daily temperature. Thus, warming significantly increased Ra /GPP by moving plants to higher positions on the shared Ra /GPP vs daily temperature relationship, but this effect was modest and only notable during hot conditions. Despite the physiological acclimation of autotrophic respiration to warming, increases in temperature and the frequency of heat waves may modestly increase tree Ra /GPP, contributing to a positive feedback between climate warming and atmospheric CO2 accumulation.

Shoot growth and seasonal changes of nonstructural carbohydrate concentrations at the upper and lower distribution limits of three conifers

Nonstructural carbohydrate (NSC) concentration in plant organs is an indicator of a balance between carbon sources (i.e., photosynthesis) and sinks (i.e., growth). Understanding how NSC concentrations change with altitude would help determine altitudinal changes in plant growth. This study compared shoot growth and seasonal changes in NSC concentrations of current-year and 1-year-old needles and branch woods between the upper and lower distribution limits of subalpine conifers Abies veitchii (1600–2000 m a.s.l.), A. mariesii (2000–2400 m a.s.l.), and Pinus pumila (2400–2800 m a.s.l.) in Japan. The lengths of 1-year-old shoots were shorter at the upper distribution limits for the three species, and concentrations and branch woods were all high in spring but decreased toward summer, increasing from summer to autumn. No clear difference was found for either parameter between upper and lower distribution limits for each species. Therefore, this study suggests that growth reduction at the upper distribution limits is due to reduction of both sink and source activities, with similar degrees for each species. However, further studies of sink and source activities, such as temperature-dependent photosynthesis and growth traits, are necessary to reveal clearly the cause of this growth reduction in high altitudes.

Cas de suie de l'érable et de chancre du peuplier dans le canton de Genève

A case of sooty bark disease and Cytospora poplar canker in the Canton of Geneva In summer 2014, a case of sooty bark disease caused by Cryptostroma corticale on an individual field maple (Acer campestre) and two cases of poplar canker due to Cytospora chrysosperma on Populus x euramericana were identified genetically for the first time on the territory of the Canton of Geneva. In both cases, the trees presented signs of very advanced dieback, accompanied by specific symptoms such as bark peeling and sooty plaques for the maple, and loose twisted bark layers and black colouring of the wood in structural branches of the poplars. Sampling was carried out in the symptomatic areas and components of the fungal flora were isolated in pure cultures in order to identify any pathogenic fungi. The molecular analysis of the rDNA internal transcribed spacer (ITS) sequences made it possible to identify precisely all pure isolates obtained. The results showed a majority presence of C. corticale in the maple tree, and of C. chrysosperma in the two poplars. Both these fungi are little known in Switzerland and Europe, and their presence is maybe associated with changes in the climate.

Cryptosphaeria Dieback of Fremont Cottonwood Caused by Cryptosphaeria pullmanensis and C. multicontinentalis in California.

Fremont cottonwood is a large and tall tree native to riparian areas in the southwestern United States. It grows along streams, rivers, and wetlands and serves many ecological and socioeconomic functions. In recent years, we observed a severe decline of Fremont cottonwood trees in California. Trees showed branches dying back, with dark-brown internal discoloration and decay of the wood of twigs, branches, or trunks. Eventually, the cambium and the bark were killed, causing a canker. The fungus Cryptosphaeria pullmanensis was isolated consistently from the necrotic wood of branches and twigs. On rare occasion, C. multicontinentalis was also isolated from symptomatic wood. Therefore, we investigated the pathogenicity in Fremont cottonwood of C. pullmanensis and C. multicontinentalis. Koch's postulates were completed in saplings and both species appeared highly virulent, producing internal necrosis and staining of the wood. This study is the first to report Cryptosphaeria dieback of Populus fremontii caused by C. pullmanensis and C. multicontinentalis. Symptoms and signs of this new disease are described and illustrated.

Contribution to Chemical Study of Stem and Branches of Trema orientalis L. (Blum) and Leucaena leucocephala (Lam.) De Wit

The use of timber in techniques of soil aggradation helps to preserve the environment by recycling sub products and residues from forestry. However, the nature of timber conditions the degradation process. The present study aimed at characterizing and comparing the chemical characteristics of wood branches, and stems of Trema orientalis and Leucaena leucocephala. By modified lignin Klason, high amounts of lignin were found in the branches than in the trunk of Trema, contradicting the results observed for Leucaena. Cellulose concentration, obtained from Kurschner and Hoffner was higher in the branches and lower in the trunk of Leucaena than in Trema. Moreover, ash contents were higher in the branches than in the trunk. C:N and lignin: N ratios, with N values significantly higher in the branches, were higher in wood trunk than in branches. Moreover, all Trema ratios were higher than those found in Leucaena. However, branches lignin/N ratio, naturally weaker, would predict a more rapid decomposition of their lignocellulose material once on the ground. Overall, pyrolysis GC-MS of branches and stems identified compounds derived mainly from lignin, followed by polysaccharides.

신생대 제4기 울릉도 나리칼데라 부석층에서 산출된 탄화목의 연륜연대 및 수종식별 연구

본 연구는 울릉도 나리칼데라에서 산출된 탄화목의 수종식별, 연륜분석, 방사성탄소 연대를 통해 고식생/고환경, 분출연대 및 화산쇄설물의 정치온도에 대한 정보를 제공하기 위해 수행되었다. 탄화목은 울릉도 최후기 화산쇄설층을 대표하는 나리테프라층의 최하부(Member N-5) 부석질 퇴적층 내에서 채취되었으며, 나이테의 원형(횡단면)이 잘 보존된 나무의 가지 부분이다. 분석결과, 수종은 소나무과 중 가문비나무속(Picea spp.)으로 식별되었으며 최외각 나이테의 연륜은 <TEX>$263+{\alpha}$</TEX> 년으로 확인되었다. 나이테는 중심(pith)에서 바깥쪽을 향해 그 나이가 점차 젊어지며 <TEX>$20,260{\pm}230$</TEX>, <TEX>$19,995{\pm}245$</TEX> 및 <TEX>$19,975{\pm}265cal\;BP$</TEX> 의 보정연대를 가진다. 가장 젊은 연대인 19,710 cal BP 는 Member N-5의 분출과 관련된 연대일 가능성이 높다. 이 결과는 후기 플라이스토세 동안 울릉도 나리칼데라는 가문비나무가 번성하였으며, 한랭 습윤한 기후조건하에 있었음을 지시한다. 광택, 취성, 색 및 조흔색 등의 특성에 기초하면, 탄화를 야기한 화산쇄설물의 최소 온도는 약 <TEX>$350{\sim}500^{\circ}C$</TEX> 정도일 것으로 추정된다. The purpose of this study is to provide an inquiry into paleovegetation (paleoenvironment), eruption age and inferred emplacement temperature of pyroclastic deposit using charcoal occurred in the Quaternary Nari Caldera, Ulleung Island. In order to obtain the data, we carried out species identification and tree-ring analysis, radiocarbon dating for the charcoal. This sample was collected from pumiceous deposit in lowermost member(Member N-5) of the Nari Tephra Formation, which corresponds to the wood branch that has well preserved the tree-ring structure. Speciation and outermost tree-ring of wood reveal Picea spp. and <TEX>$263+{\alpha}$</TEX> years. The calibrated ages from the center(pith) to the outermost tree-ring are <TEX>$20,260{\pm}230$</TEX>, <TEX>$19,995{\pm}245$</TEX>, and <TEX>$19,975{\pm}265cal\;BP$</TEX>, respectively, which are accordant with the tree-ring position. The youngest age, <19,710 cal BP would have implications for the eruptive age of Member N-5. Our results indicate that Picea spp. is the paleovegetation representing that Nari Caldera was under cold and wet climate conditions during the late Pleistocene. Based on the silky luster, brittleness, color, and streak of charcoal, etc., the lowest emplacement temperatures of pyroclastic flow are interpreted to have been at least as high as <TEX>$350{\sim}500^{\circ}C$</TEX>.

Avoidance of harvesting and sampling artefacts in hydraulic analyses: a protocol tested on Malus domestica.

A prerequisite for reliable hydraulic measurements is an accurate collection of the plant material. Thereby, the native hydraulic state of the sample has to be preserved during harvesting (i.e., cutting the plant or plant parts) and preparation (i.e., excising the target section). This is particularly difficult when harvesting has to be done under transpiring conditions. In this article, we present a harvesting and sampling protocol designed for hydraulic measurements on Malus domestica Borkh. and checked for possible sampling artefacts. To test for artefacts, we analysed the percentage loss of hydraulic conductivity, maximum specific conductivity and water contents of bark and wood of branches, taking into account conduit length, time of day of harvesting, different shoot ages and seasonal effects. Our results prove that use of appropriate protocols can avoid artefactual embolization or refilling even when the xylem is under tension at harvest. The presented protocol was developed for Malus but may also be applied for other angiosperms with similar anatomy and refilling characteristics.

FIRST REPORT OF CYTOSPORA PUNICAE ASSOCIATED WITH WOOD CANKER AND BRANCH DIEBACK DISEASE OF POMEGRANATE IN TUNISIA

Pomegranate (Punica granatum L.) is an economically important crop in Tunisia with an annual production of 23.000 tons. During May and June of 2014, severe branch dieback was observed in pomegranate plants cv. Gabsi located in Gabes region with about 8% of disease incidence. Symptoms of the disease included leaf yellowing, wood lesion and canker formation. Isolation of the pathogen was performed from 10 samples of active cankers plated onto PDA medium amended with 100 mg l-1 of tetracycline hydrochloride. Fungal colonies were then sub-cultured onto PDA medium at 22°C. All isolates were identified as Cytospora sp. based on colony morphology, conidial characteristics and pycnidia formation (Palavouzis et al., 2015). The isolates developed white mycelium, which turned green to dark brown with hyaline, allantoid, aseptate conidia (average 4-5 μm x 1.75 μm) and production of dark coloured pycnidia 300 to 450 μm in diameter after 15 days (Peduto Hand et al., 2014). Identity of these isolates was confirmed by sequencing the internal transcribed spacer region. The ITS sequences were deposited in GenBank (Accession No. KT272402). These sequences revealed 99% genetic identity with those of Cytospora punicae species available in GenBank (KJ621689; KJ621688). Pathogenicity of Cytospora punicae was evaluated by inoculation of two isolates in 1-year-old shoots of pomegranate cv. Gabsi (Palavouzis et al., 2015). The inoculated shoots developed necrotic spots with vascular discoloration spreading downward and upward from the inoculation site. Cytospora punicae was recovered from 100% of the inoculated shoots. This is the first report of Cytospora punicae causing wood canker and branch dieback of pomegranate in Tunisia.

Comparison of density and selected microscopic characteristics of stem and branch wood of two commercial trees in Ghana

The objective of this study was to investigate density and some microscopic characteristics (fibre length, vessel lumen diameter, and vessel, fibre and parenchyma proportions) of stem and branch wood of Terminalia superba (ofram) and Pterygota macrocarpa (koto). Branch and stem wood samples were obtained from two natural forest reserves. Wood density was determined in accordance with ISO 3131, whereas the anatomical investigations followed the IAWA Committee 1989 recommendations. The results indicated that at 5 % level of significance, wood density was significantly higher (p 0.1) in the branch wood of koto than that of their respective stem wood counterparts. For both species, significant difference (p 0.1) was found in ray parenchyma proportion. Branch wood density correlated significantly and positively with only fibre (r = 0.216, p < 0.05) and axial parenchyma (r = 0.286, p < 0.05) proportions but stem wood density correlated significantly and positively with fibre length (r = 0.417, p < 0.01) and fibre proportion (r = 0.490, p < 0.01) but negatively with vessel proportion (r = −0.669, p < 0.01) and vessel lumen diameter (r = −0.291, p < 0.05). The results from the present study indicated that the position of wood in a tree (stem or branch) is a factor for consideration in processing and utilizing the two species as the fibre length, vessel lumen diameter, and vessel and fibre proportions affect the strength, porosity, leachability, natural durability and drying of the lumber.

ANATOMIA DO LENHO DE RAIZ, TRONCO E GALHO DE BARBATIMÃO (Stryphnodendron adstringens (Mart) Coville)

Objetivou-se analisar o lenho de raiz, tronco e galho de barbatimão, Stryphnodendron adstringens em área de cerrado, no município de Lavras, MG. Amostras de lenho do tronco e do galho foram retiradas a 0, 25, 50, 75 e 100% da altura total do tronco e comprimento total do galho. Amostras de lenho das raízes foram retiradas a 40 cm de profundidade do solo. Qualitativamente o lenho do barbatimão possui camadas de crescimento distintas para o tronco e galho; na raiz, encontram-se pouco definidas. Porosidade difusa. Placas de perfuração simples. Pontoações intervasculares e raio-vasculares, areoladas, alternas e com guarnições. Parênquima paratraqueal vasicêntrico. Raios predominantemente unisseriados, apresentando raios multisseriados. Os raios são heterocelulares, onde o corpo do raio é formado por células procumbentes e margens com células quadradas e eretas. Observaram-se, raios homogêneos formados apenas por células procumbentes. Presença de cristais nas células dos parênquimas axiais, radiais e nas fibras. Quantitativamente, as características relevantes para o lenho foram: maior frequência de vasos para o galho; paredes das fibras mais espessas no lenho de raiz e raio mais largo no tronco.

Density, some anatomical properties and natural durability of stem and branch wood of two tropical hardwood species for ground applications

As wood resources deplete, branchwood is being promoted to supplement stemwood in Ghana, but its natural durability, which indicates its service life and can influence its acceptance and use is scarcely studied. This study compares the natural durability and some anatomical properties of branchwood and stemwood of Entandrophragma cylindricum (sapele) and Khaya ivorensis (mahogany) using Ceiba pentandra stemwood as control. Natural durability test followed field test method according to European Standard EN 252 1989 in combination with percentage weight losses while the anatomical investigations followed IAWA Committee 1989 recommendations. For each species, two branch logs were cut from each of two sampled trees from two natural forests in Ghana. Stemwood was also obtained from the same forest reserves as the branches. All sample groups were tested at air-dried moisture content of 14 ± 2 % as specified in the standard. Branchwood of both species were denser than their stemwood, but in addition to mahogany stemwood they were rated “non-durable”, while sapele stemwood was rated moderately durable. Thus at 5 % significance level, natural durability of mahogany branchwood appeared comparable to that of its stemwood whereas sapele branchwood was significantly less durable than its stemwood but more durable than Ceiba stemwood. Branchwood and stemwood vessels diameter and proportion also were significantly different (p < 0.1). Expectedly, density correlated positively with natural durability, but the correlation among anatomical properties, natural durability and density were stronger in stemwood than in branchwood. In conclusion, stem and branchwood of mahogany are both non-durable but sapele stemwood appears better than its branchwood for ground applications. Anatomical properties of stemwood influenced natural durability more than those of branchwood. For better acceptance of branchwood of the species for wood products manufacturing, further research would be necessary for additional data on their toxic extractive levels, mechanical properties and durability at different sites or/and using other drying methods.

Effect of density and moisture content on biological durability of stem and branch wood of Entandrophragma cylindricum (sapele)

Branch wood is being promoted as supplement to stem wood but its natural durability is scarcely studied. This study compared the biological durability of branch wood of Entrandophragma cylindricum (sapele) to its stem wood for ground or other outdoor applications like garden furniture at two moisture levels (i.e., 9 ± 3 and 14 ± 2 % using kiln-drying and air-drying methods, respectively). The study followed a field test method according to EN 252-1989 in combination with percentage weight loss. Branch and stem wood samples were extracted from two natural forests in Ghana. Results indicated that branch wood of sapele was marginally denser than its stem wood. Percentage weight loss of branch wood compared to its stem wood was significantly higher by approximately 108 % at 14 ± 2 % moisture content (MC) but significantly lower by 53 % at 9 ± 3 % MC. The stem and branch woods at 14 ± 2 % MC were classified respectively as moderately durable and non-durable, but at 9 ± 3 % MC both were classified as moderately durable. Visual rating indicated that at 9 ± 3 % MC branch wood could have a better service life than stem wood. Density and MC correlated positively and negatively respectively with weight loss but the association was marginally stronger for stem wood (R2 = 0.86 %) than branch wood (R2 = 0.82 %). In conclusion, sapele branch wood material dried to 9 ± 3 % MC appeared more durable than branch wood at 14 ± 2 % MC or stem wood at either 9 ± 3 or 14 ± 2 % MC. Wood products manufacturers and users should consider using well dried branch wood of sapele to supplement stem wood for ground applications. Further research is encouraged to assess other properties of the branch wood in comparison with its stem wood for a firmer conclusion to be drawn on their utilization.

"MINIMAL PRUNING" IN FREE SPINDLE BUSH PEACH TREES TO AVOID AN UNPRODUCTIVE PERIOD

In Italy the “minimal pruning system” (a definition derived from the grapevine pruning technique) is generally utilized in peach orchards. One of its main rules is to initially obtain a “free spindle bush” shape, avoiding cutting back the scion at planting time but using lateral shoots to form future fruiting branches. This experiment involved a comparison of three high density peach plots of 0.5 ha each (with 1,500, 1,100 and 1,100 trees/ha), two varieties (‘Big Top’ and ‘Magique’) budded on GF677, that were trained until the 4th year, according to three “minimal pruning techniques” applied for the free bush system. The trees were converted to a proper “spindlebush” trees between the 3rd and 4th year and resulted in: 1) equilibrated minimal pruning, practiced during Winter and Summer; 2) reduced pruning time, through reducing the number of pruning cuts, utilizing several temporary fruiting branches (4-6/tree) and pruning only in Winter; 3) further reduction of the number of cuts (time) and then equilibrating the load of fruit with thinning and pruning, leaving more fruiting branches (up to 6-10/tree) in Summer. The “free spindle bush” at a density of 1,500 trees/ha performed very well when an equilibrated method of pruning was applied (yield of 18-20 kg/tree/yr with ‘Big Top’ and 55-64 kg/tree/yr from the 2nd to the 4th year with ‘Magique’, corresponding to a cumulative yield of 192 t/ha up to the 4th year. A further reduction of the pruning time was achieved in plots 2 and 3. By utilizing the production of older wood (branches of 2-3 years) the ‘Big Top’ trees achieved a higher yield (from 32 to 46 kg/tree/yr), but ‘Magique’ yields stayed the same. The most significant result of the highest equilibrated HDP system (1,500 tree/ha) was the size of the ‘Big Top’ fruit: 57% of the fruits were classified as size A and AA, versus 17-21% in the other two systems. With ‘Magique’ 40% of fruits were sizes A-AA almost comparable with the other two systems. Between the two systems which used old bearing wood, the performance was highest and better (for size) on the second plot (1,100 trees/ha) where the Winter pruned old branches were generally no more than 4-6/tree and therefore most of the best fruiting shoots were maintained on the trees.

Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth.

For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing toward the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density (WD). We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia); three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density, and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, WD showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and WD. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation mechanisms to environment.

Transcript profiling of Populus tomentosa genes in normal, tension, and opposite wood by RNA-seq.

BackgroundWood formation affects the chemical and physical properties of wood, and thus affects its utility as a building material or a feedstock for biofuels, pulp and paper. To obtain genome-wide insights on the transcriptome changes and regulatory networks in wood formation, we used high-throughput RNA sequencing to characterize cDNA libraries of mature xylem from tension wood (TW), opposite wood (OW), and normal wood (NW), in the industrial tree species Populus tomentosa.ResultsOur sequencing generated 140,978,316 (TW), 128,972,228 (OW), and 117,672,362 (NW) reads, corresponding to 10,127 (TW), 10,129 (OW), and 10,129 (NW) unique genes. Of these, 361 genes were differentially transcribed between TW and OW (log2FC ≥ 1 or ≤ -1, FDR < 0.05), 2,658 differed between OW and NW, and 2,417 differed between TW and NW. This indicates that NW differs significantly from the wood in branches; GO term analysis also indicated that OW experienced more transcriptome remodeling. The differentially expressed genes included 97 encoding transcription factors (TFs), 40 involved in hormone signal transduction, 33 in lignin biosynthesis, 21 in flavonoid biosynthesis, and 43 in cell wall metabolism, including cellulose synthase, sucrose synthase, and COBRA. More than half of the differentially expressed TF showed more than 4-fold lower transcript levels in NW compared with TW or OW, indicating that TF abundances differed dramatically in different wood types and may have important roles in the formation of reaction wood. In addition, transcripts of most of the genes involved in lignin biosynthesis were more abundant in OW compared with TW, consistent with the higher lignin content of OW. We constructed two transcriptomic networks for the regulation of lignin and cellulose biosynthesis, including TFs, based on the co-expression patterns of different genes. Lastly, we used reverse transcription quantitative PCR to validate the differentially expressed genes identified.ConclusionsHere, we identified the global patterns and differences in gene expression among TW, OW, and NW, and constructed two transcriptomic regulatory networks involved in TW formation in P. tomentosa. We also identified candidate genes for molecular breeding of wood quality, and provided a starting point to decipher the molecular mechanisms of wood formation in Populus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1390-y) contains supplementary material, which is available to authorized users.

Histological and ultrastructural alterations in the Ailanthus excelsa wood cell walls by Bjerkandera adusta (Willd.) P. Karst

Ailanthus excelsa Roxb. requires less care than other species and thrives in arid and semi-arid regions. Therefore, it becomes an important choice for forestry programs. Young branches of these trees are frequently invaded by the fungus Bjerkandera adusta (Willd.) P. Karst. The main aims of this study were to characterize the wood decay pattern and evaluate the extent of damage caused by the fungus. Infected samples were studied using light microscopy, confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Wood of the dead branches became pale white and very soft. In vitro decayed wood showed extensive weight loss of wood blocks (68.6%) at the end of three months. In the xylem, fibres were the most severely affected cell types, whereas wall structure of the axial parenchyma remained virtually unaltered. Unlike axial parenchyma, walls of the ray cells formed several boreholes and finally collapsed in the advanced stage of decay. By contrast, the middle lamella of all the xylem elements remained intact even at the end of three months. In the early stages of infection, vessels appeared to be resistant to the fungal action but they also became eroded at the advanced stage. The degradation pattern showed anatomical characteristics of both the white-rot and soft-rot type of decay. Thinning of walls from the lumen side and appearance of U-notches resembles white-rot decay, while tunnels through the S2 layer of the fibre wall added the characteristics of the soft-rot decay pattern. Extensive weight loss of wood blocks following infection suggests B. adusta is an aggressive wood-degrading fungus.

Utilization of the pomegranate tree (Punica granatum L.) in the paper industry

In this study, the chemical composition, fiber morphology, pulp, and paper properties of the pomegranate tree (Punica granatum L.) were determined. Stem and branch wood were analyzed separately. Kraft and kraft- anthraquinone (AQ) methods were used for the pulping processes. Stem wood showed superiority to branch wood with longer, wider, thicker-walled fibers. The holocellulose, $\alpha$-cellulose, and lignin contents of branch and stem wood were 72.98%-73.50%, 38.37%-39.92%, and 21.04%-25.29%, respectively. In addition, the yield of kraft pulp made from stem wood was higher than that of branch wood. However, branch wood handsheets had higher strength properties and brightness than those of stem wood handsheets.

A falemezipar alapanyag-ellátásának alakulása Magyarországon

As a result of the sustainable forest management in Hungary, the yearly amount of exploitable timber, first of all the indigenous Sessile oak Downy oak and Turkey oak is continuously growing; however current technologies used within the wood branch are capable of utilising part of this amount only. Recently the advance of energy generation based on renewable resources has largely contributed to the contest for raw material between the wood processing companies. It is clear from the available statistical data the increase in the export of forest products further provokes the contest which may fundamentally influence domestic timber supply, consequently the future of woodworking industries. Development of plantation forestry and utilisation of waste wood and non-ligneous materials for panel production may by a solution in the long term.

Intraspecific variation of anatomical and chemical defensive traits in Maritime pine (Pinus pinaster) as factors in susceptibility to the pinewood nematode (Bursaphelenchus xylophilus)

Migration ability of the PWN through wood branch tissues of adult Maritime pine trees significantly differed among Iberian provenances and this variation was related to differences in anatomical and chemical defensive traits. The pinewood nematode or pine wilt nematode (PWN; Bursaphelenchus xylophilus) is one of the most dangerous threats to European coniferous forests, especially for the susceptible Maritime pine (Pinus pinaster), a valuable forest resource in South Western Europe. The PWN is vectored by beetles of the genus Monochamus (Coleoptera, Cerambycidae) and once inoculated in healthy branches, it quickly migrates downward to the main trunk through the resin canal system. Therefore, the anatomy of the resin canal system may modulate its migration and proliferation rates. Using material from nine Maritime pine Iberian provenances established in a common garden trial, we investigated whether these provenances differed in their (1) resin canal anatomy, (2) concentration of chemical defences (non-volatile resin and total polyphenolics) in stems and (3) ability of the PWN to migrate through the pine woody tissues in ‘in vitro’ bioassays. Whether variation in anatomical and chemical defensive traits relates to differences in PWN migration across populations was also investigated. Significant intraspecific variation in anatomical and chemical defensive traits and in nematode migration rates through pine tissues was observed. Moreover, the variation in nematode migration rate among pine provenances was related to differences in both anatomical and chemical features. Overall, this study highlights the role of plant genetics in the development of defensive traits against this harmful coniferous pest. The observed intraspecific variation should be taken into account when considering breeding as a strategy to provide areas of high risk of PWN with resistant genetic material.

Der Christbaum in den oberrheinischen Städten des 16./17. Jahrhunderts

The birthplace of the Christmas tree is the territory of the Aleman people, thus the territories of Baden and Alsace along the upper part of the river Rhine. Its direct predecessors are the maypole trees during winter and Christmas time, thus the branches of pine trees with which the houses, economical and agricultural buildings, fences and wells along the upper Rhine were decorated inside and out during the midwinter festivities (Christmas, New Year etc). According to a medieval legal principle in upper Alsace, the peasants had the right to bring a cartful of wood (branches of pine trees in the first place) on Christmas Eve from the forest. Written legal principles and customs recording this habit can be found in many cities of upper Alsace: Sundhofen (around 1300), Bergheim (1369), Germar (14th century).The habit of decorating houses with evergreen branches at Christmas is in Strasbourg and Freiburg 500 years old. The cities of the Alsace region have guarded their forests in the days before the midwinte...