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1.
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2.
Pinus densiflora and P. thunbergii, native to Japan, are highly susceptible to pine wilt disease caused by infection with a pine wood nematode (Bursaphelenchus xylophilus). Trees of these susceptible species have occasionally been found surviving in forests that are extensively damaged by this disease. Seedlings from a part of surviving trees that were selected as resistant families indicate lower mortality rates after the infection. The factors that prevent the symptoms from developing in resistant families of a susceptible species, P. densiflora, as based on the analysis of the pathogens behavior in the tree tissue and the anatomy of the resistant families, are presented in this paper. Nematode populations remained lower in the stems of seedlings from resistant families of P. densiflora than in the stems of non-resistant families. Areas dysfunctional in water transport developed in the stems of resistant families, but did not reach a size large enough to seriously block the ascent of sap. These results suggest that there are systems within the seedlings that prevent nematode migration and reproduction. The 2-year-old seedlings from resistant families of P. densiflora, however, did not suppress the pathogen activity. Numerous branches are a visible characteristic in the seedlings of some resistant families. The arrangement of the resin canals, the only channels in the tree to the pathogen migration, was disoriented at the joints between the branches and the main stem. Such a structure may be effective as a barrier to nematode dispersal.  相似文献   

3.
Preparation of liquid polyols from d-(+)-glucose (Glc) and its derivative, methyl--d-glucoside (m-Glc), has been studied. Direct reaction of -caprolactone (CL) with Glc (CL:Glc = 2:1–5:1 in weight ratio) at 150°C using tin(II) 2-ethyl hexanoate (SnEht2) (series A), in which melted Glc was suspended in CL, resulted in a dark-brown coloration of the reactants. The reaction was accompanied by formation of high molecular weight resins, a pH drop, production of water, and a considerable decrease in the hydroxyl value from the theoretically expected one. In the case of Glc/ethylene glycol (EG)/CL reaction system with SnEht2 catalyst at 150°C (series B), in which the weight ratio of Glc to EG was fixed at 1:1, Glc dissolved in the EG/CL mixture, but the brown coloration of the reactant mixture still occurred. In this case, the formation of water was enhanced, but the other effects found in series A were suppressed to a considerable extent. In the m-Glc/CL/SnEht2 reaction system (series C), in which m-Glc reacted with two to five times weight amounts of CL under the same conditions adopted in series A, development of the color, the production of high molecular weight materials and water, and the changes in pH and hydroxyl value were not observed. These results are discussed based on the chemical structural differences: Glc exists mostly in the hemiacetal form, but tautomerizes to the aldehyde, whereas m-Glc is an acetal and is protected from reversion to the aldehyde.  相似文献   

4.
Summary Total effect of action of the wood-destroying fungusPolyporus palustris, belonging to the brown rot group, has been studied on mango (Mangifera indica) and chorapine (Hardwickia pinnata) woods, for various periods of attack at definite intervals and the lignin liberated was extracted. It was observed that the production of lignin was found to increase; if the fungus was allowed to attack for considerable periods and approximately 50 to 60% lignin was produced within two years.  相似文献   

5.
Fifteen provenance/progeny tests of Pinus tecunumanii (Schw.) Eguiluz et Perry were assessed for upper-crown stem breakage at 5 to 8 years of age in Brazil, Colombia and South Africa. Five year results indicated that the mean percent stem breakage was moderate in Colombia (14% to 21%), low in South Africa (2% to 6%) and very low in Brazil (<1%). In the Colombian tests, trees from provenances of Mexican origin were more susceptible to wind damage than those from Central America, 20% versus 14%. Provenance order of percent stem breakage at 5 years of age in Colombia was Montebello (27%), La Soledad (25%), San Jose (20%), Chempil (20%), Jitotol (18%), Las Piedrecitas (18%), Celaque (17%), Km 47 (16%), San Vicente (13%), San Jeronimo (13%), San Lorenzo (12%) and Las Trancas (7%). Two half-sib progeny tests assessed at 8 years of age in Colombia with trees from the Mountain Pine Ridge source of P. tecunumanii exhibited 13% stem breakage. Family variation in stem breakage ranged from 0 to 44% in Colombia and 0 to 33% in South Africa at 5 years of age and were highly significant. The Spearman rank correlations in stem breakage of 36 half-sib families common to tests in Colombia and South Africa were r=0.13 and not significant. Family heritabilities for stem breakage at 5 and 8 years of age ranged from 0.17 to 0.63. Results indicate that stem breakage was more common on trees with branches of large diameter and was not strongly related to growth rate.  相似文献   

6.
Eleven provenances and 132 open-pollinated families of Pinus chiapensis were established at six locations in Brazil, Colombia, and South Africa and assessed for height, volume, and forking percent at five and eight years of age. Provenance × site and family × site interactions were examined in a subset of three trials with 38 open-pollinated families in common. Average volume production of P. chiapensis in Colombia and South Africa was 25 m3/ha/yr and 12 m3/ha/yr, respectively, at eight years of age. Provenance and family differences for height and volume were significant at the individual test sites at eight years of age. The La Trinidad (Chiapas) source was the most productive. Forking percent ranged from 3% in South Africa to 38% in San Jose, Colombia at eight years. Provenance × site interactions were significant for forking but not for height and volume. Family × site interactions were significant for height and volume but not for forking. Forty-six percent of the interaction variance between height and location was contributed by only six families. Height/diameter ratios for P. chiapensis were 0.29 and 0.39 in Colombia and South Africa, respectively, and significantly different.  相似文献   

7.
The extractive of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves was investigated. Four glucosides ofp-hydroxyphenyl derivatives were isolated, and their structures were indentified as betuloside (I), 3,4-dihydroxy-propiophenone-3--d-glucopyranoside (II), salidroside (III), and arbutin (IV). Arbutin was newly found in the leaves of shirakamba.  相似文献   

8.
The stilbene glucoside isorhapontin (5,4-dihydroxy-3-methoxystilbene-3--D-glucoside) is the major constituent of the ethyl acetate extracts fromPicea glehnii bark. Isorhapontin inhibited the hydrolytic activity ofTrichoderma cellobiohydrolase I (CBH I) for both bacterial microcrystalline cellulose and the soluble cellooligosaccharide celloheptaitol. The inhibitory effect for celloheptaitol, however, was more drastic than that for bacterial microcrystalline cellulose. The hydrolytic activity of the CBH I core domain for celloheptaitol was also inhibited by isorhapontin to a similar extent, suggesting that the interaction between isorhapontin and the core domain of CBH I is the reason for this phenomenon. The inhibition of CBH I activity by isorhapontin showed mixed noncompetitive and uncompetitive types in a concentration of the inhibitor of less than 125M. TheK i andK i values were estimated to be 57.2 and 33.3M, respectively. Whereas isorhapontin strongly inhibited CBH I activity, its aglycone isorhapontigenin (3-methoxy-3,5,4-trihydroxystilbene) showed almost no inhibition. Consequently, both the stilbenic and the-glucosidic structures in isorhapontin are essential for the inhibitory effect on CBH I activity. Isorhapontin also inhibited the activity ofTrichoderma endoglucanase I for celloheptaitol, whereas almost no effect was observed for the activities of both endoglucanases II and III.An outline of this work was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999  相似文献   

9.
A new relaxation property is discussed on the basis of creep behavior of wet wood specimens pretreated with heating at various temperatures followed by quenching. The treated samples showed more marked relaxation than that of an untreated sample. The relationship between relaxation time and heating history was represented by an equation ln() = –( f – k 1)T + [ln( g) + k 2], where ln() is the logarithmic relaxation time of wet samples after quenching, T is the difference between the heating temperature and the glass transition temperature (T g), ln( g) is the logarithmic relaxation time at T g, is a constant, f is the coefficient of thermal bulk expansion, and k 1 and k 2 are constants. It was concluded from the analysis of experimental results that the change in the relaxation property caused by heating and the following quenching is due to the temporary free volume created by freezing of molecular chain motion of wood components, most probably lignin, during quenching.This work was presented at the 52nd Annual Meeting of Japan Wood Research Society, Gifu, April 2002  相似文献   

10.
In this study, the decay resistance of untreated and thermally modified jack pine (Pinus Banksiana), aspen (Populus tremuloides), and white birch (Betula Papyrifera) was evaluated. Wood specimens were exposed to laboratory decay resistance tests using the wood-rot fungi, Trametes. versicolor, Poria placenta, and Gloephyllum trabeum for 2–12 weeks of incubation.

The results indicated that, T. versicolor fungus was virulent against all the three untreated woods, B. papyrifera (73.9% weight loss), P. tremuloides (57.1% weight loss), and P. banksiana (43.5% weight loss). P. placenta fungus affected B. papyrifera (52.4% weight loss), P. banksiana (52.3% weight loss), and P. tremuloides (36.7% weight loss). G. trabeum fungus was virulent against P. banksiana (41.53% weight loss), but less active against B. papyrifera (11.6% weight loss) and P. tremuloides (21.9% weight loss).

It was found that the weight losses due to T. versicolor fungus activity were reduced for P. banksiana (1.5% weight loss) thermally modified at 210 °C, B. papyrifera (27.9% weight loss) at 215 °C, and P. tremuloides (9% weight loss) at 220 °C compared to the weight losses of their untreated counterparts. These correspond to 96.5%, 62.2% and 84.2% of decrease in weight loss, respectively. Similar results were obtained with G. trabeum fungus. On the contrary, thermal modification on the deterioration of P. banksiana (39.1% weight loss) by P. Placenta was affected less resulting in only 25.2% weight loss relative to untreated wood.  相似文献   


11.
The density (), dynamic Young's modulus (E), loss tangent (tanL) in the longitudinal (L) direction, and the dynamic shear modulus (G), loss tangent (tanS) in the LT or LR (T, tangential; R, radial) plane of woods and cane (Arundo donax L.) in air-dried and wet conditions were measured. The acoustic converting efficiency (ACE), expressed by E/3/tanL, and the factors of anisotropy, expressed byE/G and tanS/tanL, of woods were compared with those of the canes. Low-density coniferous woods had higher ACE values and were of a more anisotropic nature than the cane. These woods seemed appropriate for clarinet reed owing to their homogeneous cellular structure. The stability in vibrational properties and the anticreep properties of the woods were enhanced by the acetylation treatment. Professional clarinet players suggested that acetylated Glehn's spruce and sitka spruce were suitable for clarinet reeds.Part of this report was presented at the 48th annual meeting of the Japan Wood Research Society at Shizuoka, April 1998  相似文献   

12.
Sapwood blocks of sugi (Cryptomeria japonica) and akamatsu (Pinus densiflora) were coated with Zn/Al (45%/55%) alloy metal at thicknesses of 20–30, 90–100, and 180–200m by an arc spray gun. They were served for choice and no-choice tests with a brown rot fungus (Fomitopsis palustris), a white rot fungus (Trametes versicolor), and a pest termite (Coptotermes formosanus). Coating thickness of 20–30m was enough to prevent attacks by both test fungi, whereas 90–100m thickness was needed for protection against termite attacks. Exfoliation of the coating layers was observed during the wet-dry process in the tests. The results suggested that Zn-Al alloy metal coating treatment was applicable as an alternative method for the protection of timbers from biological deterioration when combined with an additional treatment creating a vapor barrier.This research was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998  相似文献   

13.
Zusammenfassung Während mehrer r Monate wurden Weibchen vonBoophthora erythrocephala undWilhelmia lineata am Kaninchenohr gefüttert und die Überlebensrate während der Eireifungsphase,
Nutrition and Reproduction in Palaearctic Blackflies (Simuliidae: Diptera). I. Bloodfeeding ofBoophthora erythrocephala De Geer andWilhelmia lineata Meigen on RabbitsFemales of the mammalophilic species,Boophthora erythrocephala andWilhelmia lineata, feed on cattle and horses in the field. When fed on the rabbit's ear under laboratory conditions, they differ considerably in bloodsucking activity, in mortality during digestion of blood, natality, and hatching rates of first instar larvae. InB. erythrocephala 641 wild-caught- fed in 74,1% without seasonal variation. When females were kept up to four days before feeding their bloodsucking activity did not decrease. Laboratory-emerged- usually fed in even higher rates (416/533) and 4–6 days old flies fed more frequently than younger or older females. Survival rates during digestion of blood in 4 days were 60% in wild-caught, 40% in laboratory-emerged-, and 74% in cattle-fed-. Only 29% of wild-caught and the cattle-fed- but 50% of the laboratory-emerged flies could be induced to lay eggs on wet substrate. Natality of cattle- (219 eggs/) and laboratory-emerged fed on the rabbit (225 eggs/) were significantly higher than in wild-caught rabbit-fed- (191 eggs/). The number of eggs developing to first instar larvae generally was low (42%). InW. lineata wild-caught- fed less successfully (162/407) and showed considerable seasonal variation. The best results were obtained in September and October. Keeping them in the laboratory for 1–4 days reduced the bloodsucking activity. In laboratory-emerged- the best feeding result (347/724) were obtained with 4–6 day old flies but their survival during maturation of eggs remained low (55%). It was higher with wild-caught (67%) and cattle-fed- (78%). In all cases 60% of them could be induced to oviposit. The rabbit-fed wildcaught or laboratory-emerged flies produced significantly more eggs (183 resp. 197 eggs/) than cattle-fed ones (138 eggs/). Most egg batches contained only 16% fertilized eggs. In laboratory-emerged- ofB. erythrocephala andW. lineata the potential natality was highest in spring, lowest in summer and increased again in autumn. The number of eggs/ was affected by the blood volume. Starting with laboratory-emerged flies fed on the rabbit a production factor of 10.9 is calculated forB. erythrocephala and of 5.4 forW. lineata rearing from the imago to the first instar larva. When the larvae are reated to adults with 44% efficiency a reproduction of 2.4 resp. 1.2 per generation of females results.

Mit 4 Abbildungen und 4 Tabellen  相似文献   

14.
Thwaites  Robin 《New Forests》2002,24(2):81-95
This methodology has been developed to predict the distribution of preferable biophysical sites for three of the favored plantation species for private land rehabilitation in the Atherton Tablelands of tropical north Queensland: Araucaria cunninghamii, Eucalyptus cloeziana, and Flindersia brayleyana. The site prediction is expressed in a spatial and quantitative form of site classification. The sites (termed toposites) are characterized by soil and terrain qualities using spatial analytical techniques afforded by the predictive capacity of DTMs (digital terrain models) and conceptual regolith-terrain relationships in an explicit approach to forest site analysis through a geographic information system (GIS). Knowledge-based relationships and recorded soil-topographic data are used in this methodology to create conceptual models of climatic, terrain and parent material interaction. These guide the algorithms for digital terrain analysis through use of transfer functions and topographic DTM derivatives. Spatial regolith-terrain attribute predictions for potential toposites from DTMs are then combined with modeled climatic surfaces. The spatial arrangement of potentially favorable toposites for each of the selected species can be portrayed in raster format involving fuzzy classification. This form of classification provides multiple membership values for given regolith-terrain attributes for each grid cell. These can then be grouped as desired in an a posteriori classification to produce toposite preference in raster or vector map form.  相似文献   

15.
Specimens made of clear wood from Scots pine (Pinus sylvestris L.) were compressed semi-isostatically at 25°C in a Quintus press. Pressure ranged from 0 to 140MPa and the maximum decrease in the crosscut area was about 60%. Quarter-sawn and plain-sawn specimens were densified with the inside face (pith side) up or down. A laser-made dot grid on the crosscut area of the uncompressed specimen was used to calculate plastic strains by image analysis of the displacement of dots after compression. Multivariate models were developed to determine the causes of deformation. The lower face was restrained by the press table and remained flat whereas sides attached to the rubber diaphragm became more irregularly shaped when compressed. Most of the total compression occurred below 50MPa and was determined exclusively by pressure. Above 50MPa, wood density was more important and compression was lower in the interior of specimens and in heartwood. Plastic compressive strain occurred predominately in the radial direction and toward the rigid press table. Strains were dependent on the sawing pattern and orientation. The growth rings of quarter-sawn specimens oriented with the outer face (bark side) down tended to buckle.  相似文献   

16.
The embedment tests of laminated veneer lumber (LVL) with two moduli of elasticity (MOE; 7.8 GPa and 9.8GPa), parallel strand lumber (PSL), and laminated strand lumber (LSL) were conducted in accordance with ASTM-D 5764. The load-embedment relation for each of these engineered wood products (EWPs) was established. The directional characteristics of bearing strength (e), initial stiffness (k e), and effective elastic foundation depth were obtained from the tested results. The effective elastic foundation depth (=E/k e,E = MOE), based on the theory of a beam on elastic foundation, was obtained from thek e and MOE. An of 90° (perpendicular to the grain) was calculated by dividingE 90 [MOE of 90° from the compression test, but MOE of 0° (E 0), parallel to the grain, obtained from the bending test] byk e90, the initial stiffness of 90°. This study aimed to obtain the bearing characteristics of each EWP, taking into consideration their anisotropic structures, for estimating the fastening strength of a dowel-type fastener. The relations between the bearing coefficients ( e,k e,) on the loading direction and dowel diameter were established from the load-embedment curves. Based on the results of the embedment test, tested EWPs showed different tendencies in all directions from wood and glued laminated timber.Part of this study was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999  相似文献   

17.
The purpose of the study was to investigate the relation between the skin temperature of the palm and sensory cold-warmth after contact with some materials. Ten men and ten women were selected and introduced to 21 kinds of material for a contact test of 30 min without seeing the specimens in a climate-controlled room at 25±1C and 65% relative heemidity. The palm-contacted test materials and skin temperature of the palm, central fingertip, and back of the palm were measured during the experiment. A sensory evaluation test was applied to evaluate the contacted sensory cold-warmth. Results showed that the maximum temperature decrease of the fingertip (T d) was positively related to the natural logarithm of the material's specific gravity (ln u) and to the natural logarithm of the material's thermal conductivity (ln). There were also negative linear relations between the contacted sensory cold-warmth (S) with ln u and ln; and there was a negative linear relation betweenS withT d and betweenS with the value ofT d by . The thermal osmotic coefficient (b) of wood and wood-based materials ranged from 3.63 to 3.97, and the materials were qualified as good thermal insulation materials. Furthermore, there was a negative linear relation betweenS andb. Accordingly, it is possible to evaluate the contacted sensory cold-warmth relying on the basic thermal properties of material.Part of this report was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 2–4, 1999  相似文献   

18.
Data from a trial of 36 families at Little Wittenham, North Oxford was used to assess growth traits and stem form in common ash (Fraxinus excelsior, L.). The trial followed a design described by Barnes (Silv Genet 44(2–3):81–88, 1995) as the Breeding Seedling Orchard (BSO). The objectives of the study were to determine variation in growth and form traits and estimate genetic parameters of families. Assessments conducted at 3–8 years for height, diameter at breast height (dbh), straightness and forking showed significant differences (P < 0.05) among families with Guys (19), Settrington (34), Overbury (23) and Grimthorpe (36) being the best performers while Coleford (3 and 5) Gwynedd (27) and Bacheiddon (32) were the least performers. At the overall level, the additive genetic coefficient of variation (CVA) ranged between 10.2 and 12.7% for height and 1.5 and 2.1% for dbh. Height had a high genetic correlation (rg = 0.85) with dbh whilst forking had low correlation (rg = 0.25) with height. Estimates of heritability decreased with age from  = 0.62 at 3 years to  = 0.30 at 8 years for height while values for dbh decreased from  = 0.48 at 4 years to  = 0.27 at 8 years. Some genetic gains are possible despite the low genetic variation among families; height had the greatest potential of genetic gain (12.5% at 8 years). Results suggest that early selection of superior families of Fraxinus excelsior appears to be feasible and it could be possible to achieve simultaneous improvement in both growth and form.  相似文献   

19.
Xylan prepared from culms of kumaizasa (Sasa senanensis Rehd.), a representative species of bamboo grass, was hydrolyzed with-xylanase ofStreptomyces olivaceoviridis E-86. Four arabinoxylo-oligosaccharides and two glucuronoxylo-oligosaccharides were isolated from the enzymatic hydrolysate of the xylan by chromatography on a charcoal column, a Dowex 1-x8 column, a Toyo-pearl HW-40S column, and a LiChrospher 100 NH2 column and on preparative paper chromatography. The results of the structural analyses of the saccharides showed that the isolated oligosaccharides had the structures of 32--l-arabinofuranosyl-xylobiose, 32--l-arabinofuranosyl-xylotriose, 32--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylobiose, 33--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylotriose, 23--4-O-methyl-d-glucuronosyl-xylotriose, and 23--d-glucuronosyl-xylotriose. From the structural analysis of the oligosaccharides derived from the xylan, kumaizasa xylan was concluded to be a kind of arabinoglucuronoxylan having not only stubs of singlel-arabinose and singled-glucuronic acid but also stubs of disaccharide units such as-d-xylopyranosyl-(1 2)-l-arabinofuranose.  相似文献   

20.
To find a desirable method for estimating the length effect on tensile strength ( t), we used three methods to analyze the t data from a Japanese larch (Larix kaempferi) small, clear specimen. These methods included a nonparametric method, the projection method of Hayashi, and a proposed method. The estimated length effect parameters (g) by the nonparametric method were 0.0237 and 0.0626 for 50th and 5th percentile t distributions, respectively. The projection method requires a standardE f level (E *: dynamic Young's modulus), arbitrarily chosen for calculating theg value. Theg values from the projection method were 0.1122 for lowE *, 0.0898 for averageE *, and 0.0759 for highE *. The estimatedg values by the proposed method using selected t data were 0.1020 and 0.1838 for the 50th and 5th percentiles, respectively. Among the three methods, the nonparametric method did not consider the different distribution of Young's modulus among specimens, and the estimated length effect parameters (g) by this method were small. The projection method reduced the influence of Young's modulus, but the length effect parameters varied with theE * level. The proposed method minimized the dependence onE f distributions among specimens. we believe the latter method is desirable for estimating the length effect on tensile strength.  相似文献   

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