Note sur l'aptitude lignivore du Lachnellula willkommii (Hartig) Dennis,agent du chancre du mélèze

Note on the wood destroying capacity of Lachnellula willkommii (Hartig) Dennis, the larch canker fungus. The wood destroying capacity of Lachnellula willkommii in larch was studied in vitro using a method based on loss of weight. Two species of larch and their hybrid were used. The behaviour of the fungus on sapwood and heartwood differed.     

Etude experimentale du transport de Pinoculum de Ceratocystis fimbriata f. platani par ľeau ?une riviere

Dissemination of Ceratocystis fimbriata f. platani inoculum by river water . C. fimbriata was detected up to 108 m downstream from pieces of diseased plane tree placed in a fixed site in a river in Southern France. Assessment of C. fimbriata was realized by a trapping method with healthy wood.     

Über Auswirkungen des Tannensterbens auf die Holzeigenschaften der geschädigten Bäume

Zusammenfassung Das Holz mehrerer gesunder, kr?nkelnder, absterbender oder bereits abgestorbener Tannen aus 3 in st?rkeren Ma? vom Tannensterben betroffenen bayerischen Wuchsgebieten war teils unmittelbar nach der F?llung, teils nach 3- bis 6-monatiger Lagerung im Wald auf Pilzbefall und m?glicherweise eingetretene Wertminderungen untersucht worden. Mit Ausnahme eines schon vor l?ngerer Zeit abgestorbenen Stammes waren alle H?lzer bei Versuchsbeginn noch frei von Mikroorganismen oder lediglich von Bakterien besiedelt. Nach einer gewissen Lagerzeit hatte neben dem Bl?uepilzCeratocystis piceae und einigen anderen harmlosen holzbewohnenden Ascomyceten oderFungi imperfecti gelegentlich auch der intensiv verf?rbende, das Tannenholz aber nur langsam abbauende Wei?f?uleerregerStereum chailletii die Probeabschnitte befallen. Zwischen dem Holz gesunder und gesch?digter Tannen war weder zum Zeitpunkt der F?llung noch sp?ter ein deutlicher qualitativer Unterschied erkennbar und die Holzdichte bzw.-festigkeitseigenschaften wurden durch eine Waldlagerung von maximal 6 Monaten nicht nennenswert beeintr?chtigt. Auch für die Anf?lligkeit gegenüber holzzerst?renden Pilzen war der Gesundheitszustand der untersuchten Tannen ohne Bedeutung.

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Effects of the fir dieback on the wood properties of the affected trees

Summary Several healthy, diseased, dying, or already dead silver firs from each of three Bavarian growth areas considerably afflicted by fir dying were examined, regarding fungal attack and possible changes in their strength properties, immediately after felling as well as after 3 or 6 months of forest storage. At the onset of the investigation all wood samples were still largely free of microorganisms or merely colonized by bacteria, with the exception of one tree that had already died some time ago. After a certain storage period occasionally the white rot fungusStereum chailletii, which strongly discoloures and slowly decomposes fir wood, appeared besides the blue staining fungusCeratocystis piceae and several other harmless wood inhabiting ascomycetes orfungi imperfecti. Wood density and strength properties were not significantly affected during forest storage for several months, and neither immediately after felling nor later a clear difference between the wood of healthy and that of diseased firs was noticeable. Their state of health also had no influence on their reaction towards the attack of wood destroying fungi.

     

Beziehungen zwischen der Ausbreitung künstlicher Fomes annosus-Infektionen in den Stämmchen zweier Fichtenklone und einigen holzchemischen Eigenschaften

The spread of Fomes annosus from artificial infections of stems, in relation to the chemical characteristics of timber of two spruce clones . Differences in the spread of Fomes annosus in two spruce clones (Picea abies Karst.), which were found by DIMITRI, may be attributed to differences in the properties of the wood from the two clones, detected in laboratory tests. Wood meal from the more resistant clone R inhibited Fomes annosus in bioassays more than wood meal from the more susceptible clone A. Wood from clne A-trees showed a higher nitrogen content than wood from clone R-trees.     

Le champignon mycorrhizien Gomphidius glutinosus,un puissant antagoniste de Fomes annosus en culture pure

Gomphidius glutinosus a powerful antagonist of Fomes annosus in pure culture. F. annosus isolated from spruce was strongly inhibited by Gomphidius glutinosus found under Picea abies. In presence of the pathogen, Suillus placidus, a very probable mycorrhizal fungus of Pinus cembra and a moderate antagonist of F. annosus, produces a yellow reacting antibiotic substance.     

Recherche sur la nutrition azotée de plusieurs souches1 de ĽArmillaria mellea

Investigation of nitrogen nutrition in different strains of Armillaria mellea. I. Utilisation of different sources of nitrogen. The assimilation of different forms of nitrogen - NO₃-, NH₄+ and L-asparagine by isolates of Armillaria mellea from France and Poland was investigated. Both the growth aspect, in which mycelial biomass production was related to the utilisation of nitrogen sources, and the morphological aspect, involving aerial mycelium, sclerotia and rhizomorphs, were studied. Significantly difterent effects were recorded for the influence of nitrogen source, the period of growth and their interaction on the growth of various isolates. Different nitrogen sources significantly affected sclerotial and rhizomorph formation. Isolates of A. mellea, geographically and genetically different, were shown to be also physiologically specialised as was also C. tabescens.     

Studies of extraction damage decay in crops of Picea abies in southern England

Trees in a well-grown crop of Picea abies were subjected to wounding and inoculation with Stereum sanguinolentum at three-monthly intervals over a period of one year. The pattern of fungal colonisation in wood beneath wounds of various types is described.     

Lignin-degrading activity of edible mushroom <Emphasis Type="Italic">Strobilurus ohshimae</Emphasis> that forms fruiting bodies on buried sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) twigs

Strobilurus ohshimae is an edible mushroom, and it specifically forms its fruiting bodies on buried sugi (Cryptomeria japonica) twigs. In this research, we studied lignindegrading activity of S. ohshimae. We isolated 18 strains of S. ohshimae from various regions of Japan, and determined their lignin degradation rates on sugi wood meal medium. All the strains of S. ohshimae degraded approximately 6%–12% of sugi lignin in 30 days, and these lignin degradation rates were 1.5–3 times higher than those of Trametes versicolor, which is a typical lignin-degrading fungus. Among the three main lignin-degrading enzymes, activity of lignin peroxidase and manganese peroxidase was not observed, while 4340U/g of laccase was produced in 30 days. To investigate the effect of wood species on lignin degradation by S. ohshimae, the lignin degradation rate and laccase productivity on sugi wood meal medium were compared with those on beech (Fagus crenata). In T. versicolor, both lignin degradation rate and laccase productivity were higher on beech than on sugi. Conversely, in S. ohshimae, lignin degradation rate and laccase productivity were higher on sugi than on beech. Therefore, it was suggested that coniferous lignin is not always difficult to degrade for the fungi that inhabit softwood. Part of this article presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

Méthode ?estimation de la hauteur de pourriture dans le tronc des épicéas sur pieds attaqués par le Fomes annosus (Fr.) Cooke

Estimating the height of decay in standing Norway spruce attacked by Fomes annosus (Fr.) Cooke. A method is given for estimating the height of decay due to Fomes annosus in standing Norway spruce. A good correlation is provided by the height of the decay and, at the 1,30m level, the diameter and stage of the decay. The data were obtained using Pressler borings.     

In vitro interactions in artificial and wood‐based media between fungi colonizing stumps of Sitka spruce

Interspecific interactions between fungi that colonize stumps of Picea sitchensis in Scotland were tested in dual cultures on Norkrans agar, spruce sawdust and in autoclaved blocks cut from roots. Isolates were ranked according to competitive ability on the different media, based on their ability to overgrow competitors or to form deadlock interactions. On the defined medium, Phaeolus schweinitzii was the species most able to overgrow competitors, followed by Stereum sanguinolentum and Heterobasidion annosum; Resinicium bicolor was the least able to overgrow competitors on this medium. By contrast, R. bicolor was the most competitive on spruce sawdust medium. Deadlocking interactions were formed most often in dual cultures on Norkrans agar. Observation of hyphal interactions on Norkrans agar under the microscope identified several different response types including growth of thin hyphae compared to control cultures, hyphal coiling, vacuolation of hyphae, hyphal lysis of one competitor and deposition of crystals in the agar. Hymenomycetes caused varying amounts of decay in autoclaved root blocks. Resinicium bicolor was able to replace other species in most co‐inoculations. Stereum sanguinolentum appeared to be the least competitive species in root block inoculations, being replaced by Melanotus proteus and R. bicolor, although interactions with H. annosum varied widely. These results indicate that substrate has a marked effect on interspecific fungal interactions, with wood‐based, particularly intact woody tissues closely matching competitive behaviour displayed in the field.     

Fomes annosus (Fr.) Cke. und andere Stammfäulepilze in einem Douglasienbestand,Pseudotsuga menziesii (Mirb.) Franco1

Fomes annosus (Fr.) Cke. and other decay fungi in a Douglas fir stand, Pseudotsuga menziesii (Mirb.) Franco. 40% of the trees in a 40 years old Pseudotsuga menziesii stand showed butt rot. 85 trees were analysed for decay fungi. Fomes annosus, the most frequent fungus, also invaded the sap wood. Factors of the soil favourable to the rot and the possibility of transmission of the most frequent decay fungus, Fomes annosus, from (a) neighbouring spruce stands, (b) from the roots of Scots pine from the previous crop arc discussed. Caniophora puteana was isolated from about 10% of the butt rots. The importance of Calocera viscosa which grew out of the central decay of twelve trees as a decay fungus is still under investigation.     

Identification of wood‐decay fungi and assessment of damage in log depots of Western Black Sea Region (Turkey)

The aim of this study was to determine and quantify the wood‐decay fungi found on logs of forest tree species (beech, oak, hornbeam, Scots pine and fir) stored in log depots located in six different provinces in the Western Black Sea Region of Turkey. Additionally, it was aimed to determine the natural durability of some important wood species against the most commonly detected wood‐decay fungi. Eighteen families, 31 genera and 45 species belonging to the division Basidiomycota were detected; Antrodia crassa was identified for the first time in Turkey. The abundance of Panus neostrigosus, Polyporus meridionalis, Trametes hirsuta, T. versicolor and Stereum hirsutumincreased significantly with the holding time of the logs (r = 0.99, 0.87, 0.53, 0.57 and 0.78, respectively, p < 0.05). The majority of the fungal species were detected on logs stored in depots for 4–6 years (66%). The percentage of fungal species found on the logs with a holding time of three years or less was 29%, whereas the percentage for those detected on logs stored for seven or more years was 31%. Among the wood species, the greatest number of fungal species (29) and highest amount of fungi (2,539) occurred on beech wood. Natural durability tests showed that T. versicolor caused the greatest loss of wood mass, with an average of 23%. Field studies and natural durability tests performed in the laboratory showed that beech wood lost the most mass among the timber species studied.     

Comportement in vitro du Sparassis crispa Wulf. ex Fr. et du Sparassis laminosa Fr

Behaviour in vitro of Sparassis crispa Wulf. ex. Fr. and Sparassis laminosa Fr . Sparassis crispa and S. laminosa are described in culture following the method used by Nobles. S. crispa is a very active wood destroying fungus in blocks of Douglas fir (sapwood and heartwood) in laboratory tests. The cauliflower-like fructifications are easily produced on malt-agar and could be produced on a large scale.     

Optimisation of a two-stage heat treatment process: durability aspects

Heat treatment of wood at relatively high temperatures (in the range of 150–280°C) is an effective method to improve biological durability of wood. This study was performed to investigate the effect of heat treatment process optimisation on the resistance against fungal attack, including basidiomycetes, molds and blue stain fungi. An industrially used two-stage heat treatment method under relatively mild conditions (<200°C) was used to treat the boards. Heat treatment of radiata pine sapwood revealed a clear improvement of the resistance against the brown rot fungi Coniophora puteana and Poria placenta. Increasing process temperature and/or effective process time during the first process stage, the hydro thermolysis, appeared to affect the resistance against C. puteana attack, but the effect on the resistance against P. placenta was rather limited. Heat treated radiata pine showed a limited resistance against the white rot fungus Coriolus versicolor and process variations during the hydro thermolysis stage appeared not to affect this resistance. A clear difference between the resistance of heat treated Scots pine sapwood and heartwood against fungal attack is observed. Scots pine heartwood showed a higher resistance against C. puteana and P. placenta but also against the white rot fungus C. versicolor. Similar results were obtained when heat treated birch was exposed to brown and white rot fungi. Heat treatment showed an improved resistance against C. puteana attack, especially at higher temperatures during the hydro thermolysis stage. A clear improvement of the durability was also observed after exposure to the white rot fungus C. versicolor and especially Stereum hirsutum. Increasing the process temperature or process time during the hydro thermolysis stage appeared to have a limited effect on the resistance against C. versicolor attack. Heat treated radiata pine and Norway spruce were still susceptible to mold growth on the wood surface, probably due to the formation of hemicelluloses degradation products (e.g. sugars) during heat treatment. Remarkable is the absence of blue stain fungi on heat treated wood specimen, also because the abandant blue stain fungi were observed on untreated specimen. Molecular reasons for the resistance of heat treated wood against fungal attack are discussed in detail contributing to a better understanding of heat treatment methods.     

Infektion und Abbau des Wurzelholzes von Fichte durch Fornes annosus1

Infection and Deterioration of Spruce Root Wood by Fornes annosus . The paper describes the mode of infection and subsequent deterioration of spruce root wood by Fornes annosus using light and electronmicroscopic observations. In the secondary xylem the overall penetration of cell walls is effected by means of microhyphae which produce boreholes. The degradation of cell walls is initiated in the S₂ layer by diffusion of enzymes along the cellulose fibrils with subsequent hydrolysis of the amorphic incrusting substances.     

Test ?inhibition de ľactivité cambiale du Peuplier par Hypoxylon mammatum: mise au point et application

Test of inhibition of cambial activity of poplar by H. mammatum: development and application. A test was developed in vitro in order to estimate the inhibition of hosts’cambium by H. mammatum and applied to a large number of poplar clones. Toxicity of the culture filtrate appears to be selective but not necessarily specific.     

Wundfäule in Fichtenwaldungen mit alten Schälschäden

Wound decays in spruce stands following bark stripping . 2083 trees in 91 sample plots on four trial areas (24 ha) were examined for bark stripping and decay. Only 25% of trees showed no injury. Of the injured trees, 73% showed some degree of decay, 10% discoloration. and 17% neither decay nor discoloration. Of the wood destroying fungi isolated Fomes annosus was dominant and appeared to be the most important and widespread of the wound inhabiting fungi in the test area. Besides the Basidiomycetes a considerable number of other fungi was isolated. The most frequent was Cylindrocarpon cylindroides var. tenue.     

Colonization patterns and topochemical aspects of sap streak caused by Stereum sanguinolentum in Norway spruce

Fresh sapwood blocks of Norway spruce (Picea abies) were exposed to 12- and 60-day attack by Stereum sanguinolentum in pure culture and were examined with respect to structural, topochemical and colour alterations. Final stages of degradation by 5. sanguinolentum were studied on naturally decayed spruce wood after 1 year of fungal growth. The development of discoloration in the main anatomical directions of wood was assessed. Furthermore, microspectrophotometrical studies on the decomposition of cell wall polyphenols were performed. Initial signs of sap streak appeared already 8 days after fungal infection. Within the three-dimensional decay pattern, mycelial aggregations associ-ated with the ray tissue proved to be the major cause of discoloration. UV extinction measurements taken at 280 nm of different parts of cell wall transverse sections revealed a specific pattern of lignin distribution and its derivatives during fungal degradation.     

Stem-rot damage and the progress of causal fungi in old-aged Japanese larch trees at the foot of Mt. Fuji

Damage caused by stem-rot and the progress of the causal fungi in old-aged Japanese larch (Larix kaempferi (Lamb.) Carr.) was investigated at the foot of Mt. Fuji. Stem-rot was found in 75% of 108 trees investigated, and volume of rot was 6% of the total wood volume in the forest investigated. Stem-rot damage was much greater than the damage by butt-rot.Stereum sanguinolentum (Alb. and Schw. ex Fr.) Fr. infected larch trees at the greatest incidence (49.4%). However,Porodaedalea chrysoloma (Fr.) Imaz. caused the most volume loss to the trees.S. sanguinolentum infected larch stems mainly through stem wounds, and decay caused by the fungus progressed 9.75×10² cm³/year on average.P. chrysoloma infected larch stems mainly through dead branches and wounds, and the average rate of decay progress for the fungus was 2.74×10³ cm³/year.