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  • Springer  (491,730)
  • Cell Press  (16,556)
  • 1985-1989  (277,151)
  • 1980-1984  (231,135)
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Year
  • 1
    Electronic Resource
    Electronic Resource
    The induction of sun and shade leaves of the European beech (Fagus sylvatica L.): anatomical studies (1989)
    Springer
    Trees 3 (1989), S. 1-10 
    Details
    ISSN: 1432-2285
    Keywords: Differentiation ; Leaf primordia ; Fagus sylvatica ; Sun shade leaves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Primordia from buds of sun and shade twigs of European beech (Fagus sylvatica L.) were collected six times a year for anatomical investigations. Differentiation into sun-leaf and shade-leaf primordia was first observed in early August. Sun-leaf primordia had five, and shade-leaf primordia four layers of mesophyll meristem cells. With potted graft unions of beeches possible structural changes of leaf primordia were investigated. Trees adapted to shade develop sun-leaf primordia when put into full daylight, provided the transfer happened before July. Trees adapted to full daylight developed leaf primordia which remained structurally sun-leaf primordia when the plant was kept under shade conditions. Shadeleaf branches of young beech trees cut in February in order to expose the shade buds to full daylight developed either shade leaves or intermediate shade/sun leaves. These experiments show that the subtending leaf may provide the developing axillary bud with photoassimilates, but its character, whether sun or shade leaf, has no influence on the character of the developing leaf primordia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202394
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  • 2
    Electronic Resource
    Electronic Resource
    Use of labeled nitrogen to monitor transition in nitrogen dependence from storage to current-year uptake in mature walnut trees (1989)
    Springer
    Trees 3 (1989), S. 11-16 
    Details
    ISSN: 1432-2285
    Keywords: Mineral nutrition ; Xylem sap ; Nitrogen isotope ; Juglans regia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Nitrogen (N) derived from both the soil during current-year uptake, and the withintree pool of storage N was distinguished in two groups of “Serr” walnut trees using labeled fertilizer (15N-depleted ammonium sulfate) applied in different years. Mass spectrometric analysis of N in xylem sap collected periodically in spring allowed quantification of the relative contributions of N from storage and current season uptake and the transition in N usage from previously assimilated (storage) N to the onset of current season uptake of soil N. N derived from storage accounted for 〉 50% of the xylem sap N during the staminate and pistillate bloom periods and throughout the period of spur leaf expansion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202395
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  • 3
    Electronic Resource
    Electronic Resource
    Carbon transfer associated with assimilation of organic nitrogen sources by silver birch (Betula pendula Roth.) (1989)
    Springer
    Trees 3 (1989), S. 17-23 
    Details
    ISSN: 1432-2285
    Keywords: Mycorrhiza ; Heterotrophic carbon assimilation ; Betula pendula ; Hebeloma crustuliniforme ; Shade tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Qualitative and quantitative aspects of heterotrophic carbon assimilation by mycorrhizal plants of birch (Betula pendula) were examined. Plants were grown aseptically from seed in the mycorrhizal condition with the fungus Hebeloma crustuliniforme and in the non-mycorrhizal condition, with protein as their sole exogenous nitrogen source. Yields and nitrogen contents were determined in some of the plants, while the roots of others were supplied with 14C-labelled protein and their shoots exposed for up to 72 h to different irradiance regimes. Only mycorrhizal plants utilised the organic nitrogen. Uptake of carbon associated with this utilisation and its translocation to the leaves was demonstrated directly by means of autoradiography. Amounts of activity transferred to shoots were greatest in low irradiance regimes. Calculation of net carbon gain from the heterotrophic source, based upon the assumption that breakdown products of protein are assimilated as amino-acids, indicates that over a 55-day growth period up to 9% of plant C may be derived from protein. The physiological and ecological significance of these findings are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202396
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  • 4
    Electronic Resource
    Electronic Resource
    CO2 fixation in stem slices of Picea abies (L.) Karst: microautoradiographic studies (1989)
    Springer
    Trees 3 (1989), S. 24-32 
    Details
    ISSN: 1432-2285
    Keywords: Picea abies ; Stem chlorophyll ; CO2 fixation ; Microautoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Microautoradiography was used to show that chlorophyllous cells of young Picea abies stem slices are able to fix 14CO2, in the dark as well as in the light. The amount of 14CO2 fixed in the dark is much lower than that in the light. In the dark the concentration of radioactive label is equally high in all chlorophyllous cells of the stem. In the light, however, a gradient of radioactive assimilates extends from the stem surface to its centre, with the highest concentration being located in the phelloderm and the outer one-third of the cortex. This is in spite of even illumination and CO2 supply across the whole stem slice. In the dark, stem slices with and without bark show the same amount of radioactive label in the chlorophyllous cells of xylem, perimedullary region and pith. In the light, however, the concentration of radioactive assimilates in these cells is much higher in stem slices with bark than in stem slices without bark. It is assumed therefore that light fixation products of phelloderm and cortex are transported radially into the tissue inside the cambium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202397
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  • 5
    Electronic Resource
    Electronic Resource
    Uptake of water and solutes through twigs of Picea abies (L.) Karst (1989)
    Springer
    Trees 3 (1989), S. 33-37 
    Details
    ISSN: 1432-2285
    Keywords: P/V curve ; Picea abies ; Aerial uptake ; Bark permeability ; Mass flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Uptake of water and magnesium chloride solution was investigated through the outer surface of twigs of Picea abies (L.) Karst. Water uptake was determined by using pressure/volume (P/V) curves of the twigs as a basis for calculation to avoid problems of superficial extraneous water. When water was sprayed on bark and needles of 3- to 7-year-old twigs at a xylem water potential of -1.00 MPa, they absorbed as much as 80 mm3 water in 200 min/g twig dry weight as the twig water potential recovered to -0.15 MPa. With fluorescent dyes, pathways for absorption of water and solutes through the twig bark were found, particularly through the radially orientated ray tissue. In addition to uptake by mass flow, magnesium could also diffuse along a concentration gradient from the twig surface into the xylem. In the field, the magnitude of these uptake processes would depend on the concentration of elements deposited by atmospheric precipitation, the concentration gradient between the plant surface and the xylem sap, the xylem water potential and the intensity and duration of each precipitation event.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202398
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  • 6
    Electronic Resource
    Electronic Resource
    Characterization of a thermo-osmotic gas transport mechanism in Alnus glutinosa (L.) Gaertn. (1989)
    Springer
    Trees 3 (1989), S. 38-44 
    Details
    ISSN: 1432-2285
    Keywords: Alder ; Alnus glutinosa ; Gas transport ; Root aeration ; Thermo-osmosis of gases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A gas transport system based upon the physico-chemical effect of thermo-osmosis of gases in described for the black alder, Alnus glutinosa (L.) Gaertn. Air is transported through the alder's stem to the roots, thus improving O2 supply to respiring tissues of the root system. The gas transport system is investigated by means of a tracer gas technique (11% ethane in air, v/v). Gas transport depends on any source of radiant heat generating a temperature difference between the tree's stems and the atmosphere. The amount of gas transported in leafless trees is four times higher than the amount of gas reaching the roots by gas diffusion. Two-thirds of the gas is transported in the wood, only one-third in the bark. Intercellular spaces inside the porous lenticels of the bark are responsible for this kind of gas transport. Their diameters are estimated by the effusion rates of different tracer gases to be in the range of 1 μm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202399
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  • 7
    Electronic Resource
    Electronic Resource
    Delignification of subsidiary and guard cell walls of Picea abies (L.) Karst. by fumigation with ozone (1989)
    Springer
    Trees 3 (1989), S. 57-64 
    Details
    ISSN: 1432-2285
    Keywords: Delignification ; Hydroregulation ; Ozone ; Stomata ; UV absorbance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary After fumigation with ozone, the exterior periclinal walls of the stomatal apparatus of Picea abies appear to be partially delignified, as in earlier experiments with SO2. This shows up cytophotometrically as reduced UV absorption. Random samples from the stand named Wank in the Bavarian Alps clearly showed a relation between the degree of lignification of the stomatal cells and the grading of the respective trees in their damage classes. The significance of delignification for the regulatory capacity of the stomata is discussed, and a hypothesis is proposed for a specific disturbance of hydroregulation by ozone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202401
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  • 8
    Electronic Resource
    Electronic Resource
    Stomatal conductance and transpiration of Acacia under field conditions: similarities and differences between leaves and phyllodes (1989)
    Springer
    Trees 3 (1989), S. 45-56 
    Details
    ISSN: 1432-2285
    Keywords: Acacia ; Phyllodes ; Bipinnate leaves ; Stomatal conductance ; Transpiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Leaf diffusive conductance and transpiration rates in response to situations of high evaporative demand were measured in 40 Acacia species varying widely with regard to the morphological and anatomical characters of their assimilatory organs. The measurements took place in south-eastern and central Australia, central Africa and south-western Europe and included species of all three subgenera of Acacia Mill. Soil moisture conditions and consequently the water status of the experimental plants varied between the different measuring sites, some of which were regularly watered. All the species investigated showed a similar daily pattern of diffusive conductance with a morning peak and a subsequent decrease, which was more pronounced in plants growing under water stress, indicating a decisive stomatal regulation of transpiration. A relationship between the structure of assimilatory organs and leaf diffusive conductance or transpiration rates per unit surface area could not be detected in the Australian acacias. However, there are indications that the leaves of the non-Australian species operate on higher conductances than the foliage of the Australian ones. It is suggested that the observed differences in the performance of African and Australian acacias reflect the deciduous or evergreen nature of foliage rather than structural differences. In regard to taxon-specific differentiation this might implicate an ecophysiological character which separates the evergreen species of the geographically isolated subgenus Heterophyllum from the deciduous species of the subgenera Aculeiferum and Acacia with an overlapping area of distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202400
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  • 9
    Electronic Resource
    Electronic Resource
    Biochemical symptoms of stress in the mycorrhizal roots of Norway spruce (Picea abies) (1989)
    Springer
    Trees 3 (1989), S. 65-72 
    Details
    ISSN: 1432-2285
    Keywords: Picea abies ; Ectomycorrhizae ; Physiological ecology ; Forest decline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The mycorrhizal activity of spruce in a mixed-wood forest was monitored over 1 year by measuring biochemical characters in fine roots of six canopy trees and of a regrowth stand. The concentration of adenosine 5′-triphosphate (ATP), a measure of living biomass, showed two peaks per year, one at bud break and one after main shoot growth. The concentration of storage polysaccharides in mycorrhizae showed the same cycles even more pronouncedly. It is proposed that these changes reflect growth and senescence of mycorrhizae and that the timing of the cycles is controlled by translocation of assimilates from the shoot. Differences between mycorrhizae collected from canopy trees and the regrowth stand were small and not significant. Characters known to be related to fungal activity of the mycorrhizal symbiosis (concentration of trehalose, glucose uptake, respiration) also varied little among the six canopy trees. Large differences among fine-root samples from different canopy trees, however, were detected in the concentrations of ATP and storage polysaccharides, measures which seemed to be physiologically integrated within trees. If low concentrations in roots precede losses of foliage from trees, these two symptoms could be used as early indicators of growth decline in individual spruce trees.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191535
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  • 10
    Electronic Resource
    Electronic Resource
    Protein synthesis in Pinus resinosa and the ectomycorrhizal fungus Paxillus involutus prior to ectomycorrhiza formation (1989)
    Springer
    Trees 3 (1989), S. 73-77 
    Details
    ISSN: 1432-2285
    Keywords: Mycorrhizae ; Paxillus ; Pinus ; Root exudate ; Roots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings of Pinus resinosa Ait. in test tubes were inoculated with the ectomycorrhizal fungus Paxillus involutus Fr. or with discs of sterile modified Melin-Norkrans (MMN) medium. Paxillus involutus was also inoculated to control tubes in the absence of Pinus resinosa seedlings. In vivo labelling of proteins in Pinus resinosa roots and in Paxillus involutus mycelium was carried out using 35S l-methionine 1, 2, 3, 4, 5 and 7 days after inoculation. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDSPAGE) of the protein extracts from the four treatments and autoradiography demonstrated that the presence of root exudates altered protein synthesis in Paxillus involutus as three major bands disappeared when Paxillus involutus was exposed to root exudates. Protein synthesis in Pinus resinosa was also altered when Paxillus involutus was introduced into the tubes, since at least two bands were more intense when seedlings were inoculated with Paxillus involutus, as compared to control roots. No difference was observed in the growth and the label incorporation of Paxillus involutus growing with or without root exudates. Ectomycorrhizal roots were not formed during this experiment. Gene regulation in this ectomycorrhizal association occurs, therefore, prior to the formation of ectomycorrhizal roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191536
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  • 11
    Electronic Resource
    Electronic Resource
    Studies on ectomycorrhiza (1989)
    Springer
    Trees 3 (1989), S. 78-84 
    Details
    ISSN: 1432-2285
    Keywords: Picea abies ; Pisolithus tinctorius ; Phosphate uptake ; Rhizomorph function ; Telephora terrestris ; Translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Plants of Picea abies (L.) Karst were grown in mycorrhizal association with Telephora terrestris (Pers. ex Fr.) and Pisolithus tinctorius (Mich. ex Pers.) Coker and Couch on sphagnum peat in petri dishes or Perspex chambers. After 1 year T. terrestris had formed prominent rhizomorphs which were characterized by light microscopy and investigated for 32P-orthophosphate uptake. The absorbed phosphate was transported to sinks throughout the rhizomorphal system as well as into the plant. The calculated translocation velocity and flux rate in the rhizomorph were in the range of 1–3 cm/h and 0.5–4.0 × 10-10 mol cm-2 s-1, respectively. Label was observed to accumulate in the needles 2–3 days after application. Feeding a non-mycorrhized root with 32P-orthophosphate led to an accumulation of label in needles within 1 h, but no radioactivity appeared in the associated T. terrestris rhizomorphs. The rhizomorphs of P. tinctorius revealed a higher structural differentiation than those of T. terrestris. Translocation of labelled phosphorus through rhizomorphs of P. tinctorius into spruce needles was also demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191537
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  • 12
    Electronic Resource
    Electronic Resource
    The effect of ozone and season on the pool sizes of cyclitols in Scots pine (Pinus sylvestris) (1989)
    Springer
    Trees 3 (1989), S. 85-88 
    Details
    ISSN: 1432-2285
    Keywords: Inositol ; Pinitol ; Ozone ; Pinus sylvestris ; Season
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of 100 and 200 μg · m-3 (50 and 100 ppb) ozone and ambient air on 4-year-old grafts of a Scots pine clone was tested in closedtop fumigation chambers. Ozone decreased the myo-inositol and inccreased the pinitol levels in the 1-year-old needles, whereas the effect in the current-year needles was less distinct. In neither case did ambient air lead to any detectable effects on these parameters compared with controls. However, there was a pronounced chamber effect in the levels of myo-inositol and pinitol compared with trees standing in the open field, where inositol was higher and pinitol lower. There is some evidence, based on visible symptoms as well as biochemical changes, that season is an important modifier of the effect of ozone on Scots pine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191538
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  • 13
    Electronic Resource
    Electronic Resource
    Partitioning of leaf nitrogen with respect to within canopy light exposure and nitrogen availability in peach (Prunus persica) (1989)
    Springer
    Trees 3 (1989), S. 89-95 
    Details
    ISSN: 1432-2285
    Keywords: Nitrogen partitioning ; Photosyn thesis ; Light acclimation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Relationships between leaf nitrogen content and within canopy light exposure were studied in mature nectarine peach trees (Prunus persica cv. Fantasia) that had received 0, 112, 196, 280 or 364 kg of fertilizer nitrogen per hectare per year for the previous 3 years. The relationships between light saturated leaf CO2 assimilation rates and leaf nitrogen concentration were also determined on trees in the highest and lowest nitrogen fertilization treatments. The slope of the linear relationship between leaf N content per unit leaf area and light exposure was similar for all nitrogen treatments but the y-intercept of the relationship increased with increasing N status. The slope of the relationship between leaf N content per unit leaf area and light saturated CO2 assimilation rates was greater for the high N trees than the low N trees, but maximum measured leaf CO2 assimilation rates were similar for both the high and low N treatments. A diagrammatic model of the partitioning of leaf photosynthetic capacity with respect to leaf light exposure for high and low nitrogen trees suggests that the major influence of increased N availability is an increase in the photosynthetic capacity of partially shaded leaves but not of the maximum capacity of highly exposed leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191539
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  • 14
    Electronic Resource
    Electronic Resource
    Structure and function of leaf minor veins in trees and herbs (1989)
    Springer
    Trees 3 (1989), S. 96-110 
    Details
    ISSN: 1432-2285
    Keywords: Minor veins (open and closed) ; Phloem loading ; Sugar transport ; Symplastic and apoplastic pathways
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The structure of leaf minor veins in 700 species from 140 families of dicotyledons, monocotyledons and conifers has been studied by light and electron microscopy. The presence of several structural types of minor veins has been shown. The main types are open and closed veins characteristic of trees and herbs, respectively. These vein types differ by the structure of intermediate cells, and by the mechanisms of phloem loading and sugar transport. Most woody plants have intermediate cells with numerous plasmodesmal fields, symplastic transport as the main phloem loading mechanism, as well as oligosaccharides and other complex sugars as the main phloem transport substances. By contrast, the majority of herbs have intermediate cells without plasmodesmal connections, and apoplastic loading of sucrose occurs only by membrane proton cotransport. The closed type is divided into three subtypes, differing in the degree of development of the structures used for sugar uptake from the apoplast. A list of the plants investigated with their vein types is given. The evolution of the minor vein structure and phloem loading mechanism are discussed in relation to the evolution of life forms of higher plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191540
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  • 15
    Electronic Resource
    Electronic Resource
    Variations in pith eccentricity and ring width in teak (Tectona grandis L. F.) (1989)
    Springer
    Trees 3 (1989), S. 111-116 
    Details
    ISSN: 1432-2285
    Keywords: Pith eccentricity ; Ring width ; Tectona grandis ; Teak
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wood samples were collected from a teak (Tectona grandis) plantation established in Gambari Forest Reserve (Dry Forest) near Ibadan in south-western Nigeria. Values of percentage pith eccentricity (PPE) of bole cross-sections were computed using appropriate geometrical methods. Also the growth rings of the cross-sections were identified and their widths measured. Pith eccentricity and ring width did not vary significantly between plots on the site. Variations in pith eccentricity and ring width between trees on plots were very highly significant (at 0.1% probability level). Pith eccentricity and ring width varied along tree boles: the effect of height above the ground was very highly significant in each case. On average, pith eccentricity was highest at the base and top of the merchantable bole. The magnitudes of variations in both pith eccentricity and ring width along the bole differed between the plots: plots x levels interaction effect was very highly significant in each case. A decrease in ring width corresponded with an increase in the age of the vascular cambium. Only small proportions of the variation in pith eccentricity could be estimated from concomitant variations in radial growth rate (ring width), bole form factor and crown depth; the values of r 2 were 11%, 10% and 11% respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191541
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  • 16
    Electronic Resource
    Electronic Resource
    Juvenile/total foliage ratios in Eucalyptus nitens and the growth of stands and individual trees (1989)
    Springer
    Trees 3 (1989), S. 117-124 
    Details
    ISSN: 1432-2285
    Keywords: Canopy structure ; Growth ; Heteroblasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Individual trees and stands of two provenances of Eucalyptus nitens which have marked differences in retention of juvenile foliage were studied in four plantations at different elevations. The proportion of juvenile to total foliage and growth was measured at the end of the 2nd, 3rd and 4th year from establishment. Between the ages of 2 and 4 years annual stem volume increment increased in proportion to the amount of juvenile foliage retained. By age 4 years, stem volume of trees of the juvenile persistent form was significantly larger than that of the early adult form. Increasing differences in height growth with age between provenances, which were highly significant across sites by age 4, contributed to these differences in performance. There was some evidence that the largest trees of the juvenile-persistent form were those which combined mature foliage above juvenile foliage for the longest period during the transition from juvenile to mature foliage. In the early-adult form the largest trees were those which completed the transition to mature foliage rapidly. There was no difference in the ratio of foliage mass to basal area between the two forms. It is suggested that the faster growth of the juvenile-persistent form is related to higher leaf area index and not to foliage type. A provenance of E. globulus which had a higher retention of juvenile foliage at age 4 than a second provenance had a lower stem volume, thus indicating that in this species early growth rate is not determined by foliage type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191542
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  • 17
    Electronic Resource
    Electronic Resource
    Biochemical symptoms of stress in the mycorrhizal roots of Norway spruce (Picea abies) (1989)
    Springer
    Trees 3 (1989), S. 65-72 
    Details
    ISSN: 1432-2285
    Keywords: Picea abies ; Ectomycorrhizae ; Physiological ecology ; Forest decline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The mycorrhizal activity of spruce in a mixed-wood forest was monitored over 1 year by measuring biochemical characters in fine roots of six canopy trees and of a regrowth stand. The concentration of adenosine 5′-triphosphate (ATP), a measure of living biomass, showed two peaks per year, one at bud break and one after main shoot growth. The concentration of storage polysaccharides in mycorrhizae showed the same cycles even more pronouncedly. It is proposed that these changes reflect growth and senescence of mycorrhizae and that the timing of the cycles is controlled by translocation of assimilates from the shoot. Differences between mycorrhizae collected from canopy trees and the regrowth stand were small and not significant. Characters known to be related to fungal activity of the mycorrhizal symbiosis (concentration of trehalose, glucose uptake, respiration) also varied little among the six canopy trees. Large differences among fine-root samples from different canopy trees, however, were detected in the concentrations of ATP and storage polysaccharides, measures which seemed to be physiologically integrated within trees. If low concentrations in roots precede losses of foliage from trees, these two symptoms could be used as early indicators of growth decline in individual spruce trees.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01021068
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  • 18
    Electronic Resource
    Electronic Resource
    Protein synthesis inPinus resinosa and the ectomycorrhizal fungusPaxillus involutus prior to ectomycorrhiza formation (1989)
    Springer
    Trees 3 (1989), S. 73-77 
    Details
    ISSN: 1432-2285
    Keywords: Mycorrhizae ; Paxillus ; Pinus ; Root exudate ; Roots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings ofPinus resinosa Ait. in test tubes were inoculated with the ectomycorrhizal fungusPaxillus involutus Fr. or with discs of sterile modified Melin-Norkrans (MMN) medium.Paxillus involutus was also inoculated to control tubes in the absence ofPinus resinosa seedlings. In vivo labelling of proteins inPinus resinosa roots and inPaxillus involutus mycelium was carried out using35Sl-methionine 1, 2, 3, 4, 5 and 7 days after inoculation. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDSPAGE) of the protein extracts from the four treatments and autoradiography demonstrated that the presence of root exudates altered protein synthesis inPaxillus involutus as three major bands disappeared whenPaxillus involutus was exposed to root exudates. Protein synthesis inPinus resinosa was also altered whenPaxillus involutus was introduced into the tubes, since at least two bands were more intense when seedlings were inoculated withPaxillus involutus, as compared to control roots. No difference was observed in the growth and the label incorporation ofPaxillus involutus growing with or without root exudates. Ectomycorrhizal roots were not formed during this experiment. Gene regulation in this ectomycorrhizal association occurs, therefore, prior to the formation of ectomycorrhizal roots.
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    Studies on ectomycorrhiza (1989)
    Springer
    Trees 3 (1989), S. 78-84 
    Details
    ISSN: 1432-2285
    Keywords: Picea abies ; Pisolithus tinctorius ; Phosphate uptake ; Rhizomorph function ; Telephora terrestris ; Translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Plants ofPicea abies (L.) Karst were grown in mycorrhizal association withTelephora terrestris (Pers. ex Fr.) andPisolithus tinctorius (Mich. ex Pers.) Coker and Couch on sphagnum peat in petri dishes or Perspex chambers. After 1 yearT. terrestris had formed prominent rhizomorphs which were characterized by light microscopy and investigated for32P-orthophosphate uptake. The absorbed phosphate was transported to sinks throughout the rhizomorphal system as well as into the plant. The calculated translocation velocity and flux rate in the rhizomorph were in the range of 1–3 cm/h and 0.5–4.0 × 10-10 mol cm-2 s-1, respectively. Label was observed to accumulate in the needles 2–3 days after application. Feeding a non-mycorrhized root with32P-orthophosphate led to an accumulation of label in needles within 1 h, but no radioactivity appeared in the associatedT. terrestris rhizomorphs. The rhizomorphs ofP. tinctorius revealed a higher structural differentiation than those ofT. terrestris. Translocation of labelled phosphorus through rhizomorphs ofP. tinctorius into spruce needles was also demonstrated.
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    The effect of ozone and season on the pool sizes of cyclitols in Scots pine (Pinus sylvestris) (1989)
    Springer
    Trees 3 (1989), S. 85-88 
    Details
    ISSN: 1432-2285
    Keywords: Inositol ; Pinitol ; Ozone ; Pinus sylvestris ; Season
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of 100 and 200 μg · m-3 (50 and 100 ppb) ozone and ambient air on 4-year-old grafts of a Scots pine clone was tested in closedtop fumigation chambers. Ozone decreased the myo-inositol and inccreased the pinitol levels in the 1-year-old needles, whereas the effect in the current-year needles was less distinct. In neither case did ambient air lead to any detectable effects on these parameters compared with controls. However, there was a pronounced chamber effect in the levels of myo-inositol and pinitol compared with trees standing in the open field, where inositol was higher and pinitol lower. There is some evidence, based on visible symptoms as well as biochemical changes, that season is an important modifier of the effect of ozone on Scots pine.
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    Partitioning of leaf nitrogen with respect to within canopy light exposure and nitrogen availability in peach (Prunus persica) (1989)
    Springer
    Trees 3 (1989), S. 89-95 
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    ISSN: 1432-2285
    Keywords: Nitrogen partitioning ; Photosyn thesis ; Light acclimation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Relationships between leaf nitrogen content and within canopy light exposure were studied in mature nectarine peach trees (Prunus persica cv. Fantasia) that had received 0, 112, 196, 280 or 364 kg of fertilizer nitrogen per hectare per year for the previous 3 years. The relationships between light saturated leaf CO2 assimilation rates and leaf nitrogen concentration were also determined on trees in the highest and lowest nitrogen fertilization treatments. The slope of the linear relationship between leaf N content per unit leaf area and light exposure was similar for all nitrogen treatments but the y-intercept of the relationship increased with increasing N status. The slope of the relationship between leaf N content per unit leaf area and light saturated CO2 assimilation rates was greater for the high N trees than the low N trees, but maximum measured leaf CO2 assimilation rates were similar for both the high and low N treatments. A diagrammatic model of the partitioning of leaf photosynthetic capacity with respect to leaf light exposure for high and low nitrogen trees suggests that the major influence of increased N availability is an increase in the photosynthetic capacity of partially shaded leaves but not of the maximum capacity of highly exposed leaves.
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    Structure and function of leaf minor veins in trees and herbs (1989)
    Springer
    Trees 3 (1989), S. 96-110 
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    ISSN: 1432-2285
    Keywords: Minor veins (open and closed) ; Phloem loading ; Sugar transport ; Symplastic and apoplastic pathways
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The structure of leaf minor veins in 700 species from 140 families of dicotyledons, monocotyledons and conifers has been studied by light and electron microscopy. The presence of several structural types of minor veins has been shown. The main types are open and closed veins characteristic of trees and herbs, respectively. These vein types differ by the structure of intermediate cells, and by the mechanisms of phloem loading and sugar transport. Most woody plants have intermediate cells with numerous plasmodesmal fields, symplastic transport as the main phloem loading mechanism, as well as oligosaccharides and other complex sugars as the main phloem transport substances. By contrast, the majority of herbs have intermediate cells without plasmodesmal connections, and apoplastic loading of sucrose occurs only by membrane proton cotransport. The closed type is divided into three subtypes, differing in the degree of development of the structures used for sugar uptake from the apoplast. A list of the plants investigated with their vein types is given. The evolution of the minor vein structure and phloem loading mechanism are discussed in relation to the evolution of life forms of higher plants.
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    Variations in pith eccentricity and ring width in teak (Tectona grandis L. F.) (1989)
    Springer
    Trees 3 (1989), S. 111-116 
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    ISSN: 1432-2285
    Keywords: Pith eccentricity ; Ring width ; Tectona grandis ; Teak
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wood samples were collected from a teak (Tectona grandis) plantation established in Gambari Forest Reserve (Dry Forest) near Ibadan in south-western Nigeria. Values of percentage pith eccentricity (PPE) of bole cross-sections were computed using appropriate geometrical methods. Also the growth rings of the cross-sections were identified and their widths measured. Pith eccentricity and ring width did not vary significantly between plots on the site. Variations in pith eccentricity and ring width between trees on plots were very highly significant (at 0.1% probability level). Pith eccentricity and ring width varied along tree boles: the effect of height above the ground was very highly significant in each case. On average, pith eccentricity was highest at the base and top of the merchantable bole. The magnitudes of variations in both pith eccentricity and ring width along the bole differed between the plots: plotsx levels interaction effect was very highly significant in each case. A decrease in ring width corresponded with an increase in the age of the vascular cambium. Only small proportions of the variation in pith eccentricity could be estimated from concomitant variations in radial growth rate (ring width), bole form factor and crown depth; the values ofr 2 were 11%, 10% and 11% respectively.
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    Juvenile/total foliage ratios inEucalyptus nitens and the growth of stands and individual trees (1989)
    Springer
    Trees 3 (1989), S. 117-124 
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    ISSN: 1432-2285
    Keywords: Canopy structure ; Growth ; Heteroblasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Individual trees and stands of two provenances ofEucalyptus nitens which have marked differences in retention of juvenile foliage were studied in four plantations at different elevations. The proportion of juvenile to total foliage and growth was measured at the end of the 2nd, 3rd and 4th year from establishment. Between the ages of 2 and 4 years annual stem volume increment increased in proportion to the amount of juvenile foliage retained. By age 4 years, stem volume of trees of the juvenile persistent form was significantly larger than that of the early adult form. Increasing differences in height growth with age between provenances, which were highly significant across sites by age 4, contributed to these differences in performance. There was some evidence that the largest trees of the juvenile-persistent form were those which combined mature foliage above juvenile foliage for the longest period during the transition from juvenile to mature foliage. In the early-adult form the largest trees were those which completed the transition to mature foliage rapidly. There was no difference in the ratio of foliage mass to basal area between the two forms. It is suggested that the faster growth of the juvenile-persistent form is related to higher leaf area index and not to foliage type. A provenance ofE. globulus which had a higher retention of juvenile foliage at age 4 than a second provenance had a lower stem volume, thus indicating that in this species early growth rate is not determined by foliage type.
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    The effect of desiccation on viability and phospholipid composition of Acer sacharinum L. seeds (1989)
    Springer
    Trees 3 (1989), S. 144-148 
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    ISSN: 1432-2285
    Keywords: Acer saccharinum ; Desiccation ; Phospholipids ; Seed viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Phospholipid biosynthesis and composition in desiccation-intolerant silver maple seeds were determined with respect to the seed's germinability and electrolyte leakage during the desiccation process. An evident increase in the biosynthesis of phospholipids occurs during the period of high viability of the seeds. The electrolyte leakage level during this period is rather low. The more the seed's viability declines the lower is the biosynthesis of phospholipids and the higher the permeability of membranes to solutes. The total content of phospholipids as well as the content of particular phospholipids decreases with a simultaneous increase of phosphatidic acid. Presented data support the hypothesis that membrane destruction takes place during loss of water in desiccation-intolerant seeds. The nature of cell membrane damage is discussed.
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    Soluble carbohydrates of Pinus sylvestris L. sapwood and heartwood (1989)
    Springer
    Trees 3 (1989), S. 138-143 
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    ISSN: 1432-2285
    Keywords: Heartwood ; Pinus sylvestris ; Sapwood ; Soluble carbohydrates ; Starch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The amounts of glucose, fructose, sucrose, arabinose/galactose, raffinose/stachyose and starch were investigated in the outer sapwood, innermost sapwood, transition zone and heartwood of four stems of Pinus sylvestris L. The samples were taken in October and the determination of the compounds was done enzymatically. It was not possible to distinguish arabinose from galactose and raffinose from stachyose. The amounts of glucose, fructose and sucrose were greatest in the outer sapwood and decreased gradually towards the innermost sapwood and the heartwood. In the outermost heartwood glucose, fructose and sucrose were only present in trace amounts. Raffinose/stachyose showed highest concentrations in the outer sapwood and decreased towards the heartwood. In contrast, the concentrations of arabinose/galactose increased towards the heartwood and the greatest amount was found in the inner heartwood. When identified by thin-layer chromatography (TLC), arabinose was found to be present in greater amounts than galactose. The amount of starch decreased markedly towards heartwood. However, the amounts of sugars in all the studied stems was very variable. The changes in the amounts of carbohydrates in the different zones of the stems and the possible relationships of these phenomena with heartwood formation are discussed.
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    Participation of auxin and abscisic acid in the regulation of seasonal variations in cambial activity and xylogenesis (1989)
    Springer
    Trees 3 (1989), S. 125-137 
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    ISSN: 1432-2285
    Keywords: Cambial activity ; Auxin ; Abscisic acid ; Dormancy ; Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The current notion that hormonal level and cell response are clearly correlated has often been challenged recently. During the period of cambial activity, auxin content seems to control the intensity of mitosis and some features of the resulting wood, but not the duration of the active period itself. During cambial rest, the indole-3-acetic acid (IAA) level often remains high in the cambium, but the cell sensitivity to auxin is low. The decrease of auxin transport in autumn is sometimes interpreted as a major qualitative change affecting the pattern of transport, and sometimes as a secondary change occurring later than rest onset. The causes of the seasonal variation of cambial response remain unknown. A hypothesis is proposed that accounts for the structural-functional changes occurring in cambial cells during the onset of dormancy. Abscisic acid (ABA) may reduce wood production and xylem cell enlargement in late summer. An important amount of ABA may be present in the cambial zone in autumn after drought stress and in spring in the young growing shoot. Changes in ABA level do not appear to be clearly correlated with the different steps of cambial rest and activity. Beyond the role of ABA as a stress mediator, its participation in the annual regulation of cambial activity remains unclear. Its distribution in the most alkaline compartments may account for the particularities of its seasonal activity. The involvement of IAA and ABA in cambial growth is discussed within the scope of a possible annual alternation of two different metabolisms in the cambial cell.
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    Proteins as a potential nitrogen storage compound in bark and leaves of several softwoods (1989)
    Springer
    Trees 3 (1989), S. 149-153 
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    ISSN: 1432-2285
    Keywords: Storage proteins ; Softwoods ; SDS ; Page ; Bark ; Leaves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The occurrence of vegetative storage proteins in the leaf and bark tissues of several softwood species during overwintering was investigated by sodium dodecyl sulphate polyacrylamide electrophoresis. Monthly protein profiles from leaves and bark of six evergreen softwood species (Pinus strobus, P. sylvestris, Picea abies, P. glauca, Abies balsamea, and Thuja occidentalis) and the bark of one deciduous softwood species (Larix decidua) suggest that storage proteins are present in bark tissues of L. decidua, Pinus sylvestris, and P. strobus. The remaining species did not show similar specific proteins. However, the total soluble protein content which was determined during active growth and during overwintering in the same tissues indicated that protein levels were higher in the winter compared to the summer in the bark of all species and in the leaves of Pinus spp. and T. occidentalis. While vegetative storage proteins do not appear prevalent in all softwood species, proteins may constitute a major form of overwintering nitrogen storage for many species.
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    Supply and compartmentalization of potassium in mesophyll cells of the needles of spruce, Picea abies (L.) Karst. (1989)
    Springer
    Trees 3 (1989), S. 154-160 
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    ISSN: 1432-2285
    Keywords: Picea abies (L.) Karst. ; Potassium ; Nutrition ; Compartmentalization ; Cell morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The water and potassium content and the relative vacuolar volume (α = Vvacuole/Vcell) of mesophyll cells of the needles of healthy 21-yearold spruce trees [Picea abies (L.) Karst.] were determined. In 5-year-old needles α was 0.626 ± 0.178 (ovx ± SD). Potassium concentrations in the bulk tissue water ranged from about 65 to 105 mM. Simulations were made using this information and a simple two-compartmental model of the cell with the bulk cytoplasm and the vacuole and assuming that the minimum cytoplasmic and vacuolar K+ concentrations are 100–150 mM and 10–15 mM respectively. It is shown that a K+ content of needles below 50 mmol/1 tissue water would be precarious for maintenance of normal physiological and metabolic performance.
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    Biochemical differences between embryogenic and nonembryogenic calli of conifers (1989)
    Springer
    Trees 3 (1989), S. 173-178 
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    ISSN: 1432-2285
    Keywords: Conifer ; Gymnosperm ; Glutathione ; Ethylene ; Protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Embryogenic and nonembryogenic calli of loblolly pine (Pinus taeda), Eastern white pine (P. strobus), pond pine (P. serotina), white spruce (Picea glauca), and European larch (Larix decidua) were analyzed for biochemical parameters previously shown to be indicative of an embryogenic state in Norway spruce (Picea abies). Concentrations of glutathione and total reductants as well as rates of ethylene evolution and incorporation of radioactive leucine into protein in the two callus types were consistent with the Norway spruce observations. Embryogenic potential of loblolly pine and pond pine callus was predicted by biochemical analysis in advance of the appearance of somatic embryos. Other parameters such as isozyme patterns and SDS-PAGE of soluble proteins could also be used to distinguish embryogenic from nonembryogenic conifer callus. Among the species investigated, white spruce was the most difficult to sort by these methods.
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    Dormancy release in Pinus sylvestris L. and Picea abies (L.) Karst. seedlings: effects of intermittent warm periods during chilling (1989)
    Springer
    Trees 3 (1989), S. 179-184 
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    ISSN: 1432-2285
    Keywords: Annual cycle of development ; Bud burst ; Chilling requirement ; Rest period ; Simulation models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Experiments designed to test three simulation models were used to study the effects of intermittent warm periods during the chilling period on dormancy release in 2-year-old seedlings of Pinus sylvestris L. and Picea abies (L.) Karst. The effect of the intermittent period varied according to its timing. Compared with corresponding continuous chilling treatments, the intermittent periods (1) after 1–3 weeks of chilling increased the proportion of the seedlings for which dormancy was subsequently released, and (2) after 4–7 weeks of chilling substantially diminished this proportion. The intermittent periods did not affect the time required for growth initiation in forcing conditions. These results support a simulation model with a strict end-point for the rest period. On the basis of the experimental results, division of the dormant period into three sub-periods is proposed.
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    Seasonal course of translocation and distribution of 14C-labelled photoassimilate in young trees of Larix decidua Mill (1989)
    Springer
    Trees 3 (1989), S. 185-191 
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    ISSN: 1432-2285
    Keywords: Larch ; Larix ; Phloem transport ; Photoassimilate ; Translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Young trees of Larix decidua, in their 4th and 5th year of development, were permitted to photoassimilate a pulse of 14CO2 at different times throughout the growing season. After chase periods between 1 h and 7 days, the distribution of 14C in these plants was determined. CO2 fixation followed a maximum curve with highest rates of photosynthesis of 123 ± 4 μmol CO2·h-1·mg chl-1 in June. Translocation of 14C assimilate was observed throughout the growing season. The main quantity of fixed 14C was always retained in the fed leaves. Radiocarbon moved basipetally into the roots at all times, particularly in spring and late summer. Sprouting young shoots and leaves at the stem apex attracted assimilate in spring. Incorporation of 14C into soluble low-molecular-weight substances prevailed; less radioactivity was incorporated into insoluble polymeric compounds. Distribution of 14C among the sugar, amino acid and organic acid fraction was determined. Labelled free sugars were analysed.
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    Effects of wounding on the terpene content of twigs of maritime pine (Pinus pinaster Ait.) (1989)
    Springer
    Trees 3 (1989), S. 210-219 
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    ISSN: 1432-2285
    Keywords: Resin acids ; Wounding ; Pine ; Secretory structures ; Reactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary After wounding the cortical tissues of twigs of Pinus pinaster, we investigated changes in diterpene resin acid content and the ultrastructural modification of secretory structures. There was an increase in total resin acid content in the cortical and woody tissues located near the wound. Not all resin acids responded in the same way, but in wounded tissues the amounts of isopimaric acid and of the group of dehydroabietic, levopimaric and palustric acids significantly increased. The composition of cortical tissues becomes closely related to that of woody tissues. The resin acid enrichment of cortical tissues is correlated with the reactivation of the epithelial cells of the resin ducts and the de novo synthesis of resin acids demonstrated by labelling with 14CO2.
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    Stand microclimate and physiological activity of tree leaves in an oak-hornbeam forest (1989)
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    Trees 3 (1989), S. 227-233 
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    ISSN: 1432-2285
    Keywords: Microclimate ; Photosynthetically active radiation ; Wind speed ; Relative humidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In an uneven-aged, multi-species oak-hornbeam forest at Báb, SW Slovakia (former IBP Forest Research Site), a series of micrometeorological and ecophysiological measurements started in 1985. The aims of the work are to improve understanding of physiological processes (photosynthesis, respiration, and transpiration) of adult trees and stand microclimate, to collect data for simulation of the canopy (stand) photosynthesis and for ecological synthesis of the functioning of the forest ecosystem. In this paper, photosynthetically active radiation (PAR), air temperature (AT) and relative humidity (RH), wind speed (WS), and CO2 concentration ([CO2]) in and above the forest are characterized for the fully leaved season, using diurnal courses, vertical profiles and isodiagrams (isopleths). Approximately 50% of incident PAR was absorbed by the upper 4–5 m layer of leaves and only approximately 5% or less penetrated to the forest floor. Vertical gradients of AT and RH were generally low, but large differences in diurnal ranges of AT and RH were observed between vertical levels. The upper leaf canopy greatly reduced WS, and at a height of about 14 m above the ground it was close to zero. The highest diurnal [CO2] maximum and variations occurred at 1 m above the ground, and the lowest above the forest. In “good” light conditions in the forest, the entire leaf canopy (overstorey and understorey canopy) is a large sink of CO2. At night the forest stand is a source of CO2, the largest internal source being the soil and forest floor.
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    Size-dependent differential scaling in branches: the mechanical design of trees revisited (1989)
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    Trees 3 (1989), S. 241-253 
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    ISSN: 1432-2285
    Keywords: Allometric analysis ; Scaling ; Woody plants ; Acer saccharinum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Size is a key factor in determining the mechanical and functional properties of any structure. Allometric analysis allows the comparison of dimensional form at different scales. Previous descriptions of branch scaling have attempted to define a single uniform relationship governing the proportions of trees and branches over their entire size range. A new general model of scaling in woody plants is proposed in which those plants and portions of plants below a certain critical size scale allometrically becoming more slender as size increases, while those above this limit become more robust as size increases. The basis for this differential scaling is the relationship between the bending mechanics of branches, the absolute size of the branch and possibly conductance requirements. Evidence for this model is derived from a review of size scaling in trees and shrubs and from a complete analysis of a silver maple (Acersaccharinum) 13 m in height and of 370 kg wet mass.
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    Photosynthetic performance, chloroplast pigments, and mineral content of various needle age classes of spruce (Picea abies) with and without the new flush: an experimental approach for analysing forest decline phenomena (1989)
    Springer
    Trees 3 (1989), S. 161-172 
    Details
    ISSN: 1432-2285
    Keywords: Forest decline ; Picea abies ; Mineral deficiency ; Photosynthetic performance ; Air pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Damage in the older needles of Norway spruce [Picea abies (L.) Karst.] in the Fichtelgebirge (NE Bavaria, FRG) appears to result primarily from nutrient imbalances rather than from direct effects of air pollutants on the mesophyll of the needles. Support for this conclusion was obtained by altering the nutrition of older needles through the removal of terminal buds on several branches from a damaged and an undamaged spruce tree in spring. Various photosynthetic parameters, as well as the chloroplast pigment and nutrient concentrations, of 1- to 3-year-old needles on manipulated branches were compared with those of branches on which the new flush was allowed to develop during the course of the growing period. Removal of terminal buds affected only the 1-year-old needles. Elimination of the new flush resulted in a higher Ca and Mn content of the needles of the undamaged tree. This treatment also resulted in an increase of the photosynthetic capacity (under saturating light and CO2 conditions), carboxylation and light use efficiency, as well as net photosynthesis under natural conditions of the 1-year-old needles on the yellow chlorotic tree. This was accompanied by higher chlorophyll concentrations and an increase in Mg, Ca, Mn, and Zn content, and no visible signs of chlorosis developed in the experiment. By contrast, the needles of twigs in which the new flush was allowed to develop exhibited reductions in mineral content in the middle of the year. This was especially true for the elements Mg and Ca, and was accompanied by needle chlorosis and a depression of the capacity of photosynthesis. Thus it appears that there is a close relationship between the development of needle damage and nutrient imbalances in spruce. The retranslocation of elements from the 1-year-old needles to the new flush seems to play a major role in the development of needle bleaching. This approach thus supports the hypothesis described above and confirms a preliminary test with a similar experimental design, which had been conducted earlier.
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    URL: http://dx.doi.org/10.1007/BF00226652
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    Structure and development of sieve cells in the secondary phloem of Larix decidua Mill. as related to function (1989)
    Springer
    Trees 3 (1989), S. 192-209 
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    ISSN: 1432-2285
    Keywords: Autoradiography ; Fine structure ; Larch ; Larix decidua ; Sieve cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Only one or two layers of sieve cells of the previous year's phloem in lateral branches of Larix decidua persist as fully mature cells. Immature sieve cells or cambial derivatives that have not completed differentiation may also over-winter. Periclinal cell divisions of the vascular cambium were first observed by mid-April. During the short period of greatest cambium activity (mid-April to mid-May), the early phloem is laid down. Late phloem is formed over a much longer period, from mid-May to late September. Microautoradiography revealed that only mature sieve cells of the early phloem are involved in translocation of 14C assimilates in June. The fine structure of actively translocating sieve cells is described. The impact of structure on long-distance transport of assimilates is discussed.
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    URL: http://dx.doi.org/10.1007/BF00225353
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    Effects of wounds on the terpene content of twigs of maritime pine (Pinus pinaster Ait.) (1989)
    Springer
    Trees 3 (1989), S. 220-226 
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    ISSN: 1432-2285
    Keywords: Pinus pinaster ; Wound effect ; Mono- and sesquiterpene modifications ; Cortical tissue essential oil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of wounds on the volatile terpene composition of the living bark of Pinus pinaster Ait. (maritime pine) twigs was investigated with respect to the processes of mono- and sesquiterpene hydrocarbon biosynthesis. The large increase in the amounts of α- and β-pinene is a characteristic feature after a mechanical injury, whereas the quantities of the other terpenes are only slightly increased. This is due to the reactivation of the resin duct secretory cells of primary origin located in cortical tissues. The effect of wounding is observed over a long period and the terpene profiles are very different at the end of the experiments as compared with the initial profiles of the same tissues. The traumatic essential oil (obtained after mechanical traumatism) resembles an oleoresin extracted from tissues of secondary origin. Statistical analysis underlines the effects of the between-tree variations and of the dates of application of the wound.
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    URL: http://dx.doi.org/10.1007/BF00225355
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    Stand microclimate and physiological activity of tree leaves in an oak-hornbeam forest (1989)
    Springer
    Trees 3 (1989), S. 234-240 
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    ISSN: 1432-2285
    Keywords: Microclimate ; Leaf photosynthesis ; Turkey oak ; Hornbeam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The photosynthetic activity of the Turkey oak (Quercus cerris L., height 22 m) and common hornbeam (Carpinus betulus L., height 17 m) in a deciduous forest stand was analysed. Trees studied grew in an uneven-aged forest (80 years old on average, main canopy surface at a height of 18m) forming the former IBP forest research site at Báb, SW Slovakia (Czechoslovakia). The average photosynthetic rate of oak foliage was higher than that of hornbeam. Net photosynthetic rate at saturating photon flux rate (PNmax) of hornbeam amounted to only 60% of that of oak for the leaves of the upper canopy layer (UCL) and to 67% for the leaves of the lower canopy layer (LCL). In the summer months the main photosynthetic activity of this deciduous stand was focused upon the UCL leaves and oak species. The relationship between PN and photon flux rate, as well as the diurnal course of PN and stomatal conductance (gs), was calculated using a mathematical model. The diurnal course of PN and gs were similar for both tree species and both types of leaf. Maximal gs values were observed at noon. The lower values of compensation photon flux rate (Γ1) and photosynthetic efficiency (α) but higher values of the maintenance respiration rate (RM), confirmed the higher shade tolerance of the hornbeam. The dark respiration rate (RD) of the UCL leaves was higher than that (RD) of the LCL leaves. Various photosynthetic features and production capacity of the above-mentioned types of leaf expressed the adaptation pressures to radiation conditions. In the stand studied, the primary production of the greater part of the crown depended on the vertical foliage distribution and on light penetration during the midday hours.
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    Geometry-defining processors for engineering design and analysis (1989)
    Springer
    The visual computer 5 (1989), S. 304-315 
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    ISSN: 1432-2315
    Keywords: Geometry definition ; Interactive peripheral ; Mesh generation ; Multi-processors ; Parallel processing ; Partial differential equations ; Reconfigurable architectures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Critical issues of interactive three-dimensional geometry definition and high-speed parallel computation are addressed in a unified fashion by Geometry-Defining Processors (GDPs). GDPs are microprocessors housed in three-dimensional physical polyhedral packages which can be easily manually assembled or reconfigured to construct approximate scale models of physical objects or domains. An individual GDP communicates with neighboring GDPs in an assembly through optical ports associated with the faces of its package. An assembly of communicating GDPs is able to bothdefine a system geometry and, operating as an optimally connected parallel processor,solve the associated continuum partial differential equations required for design evaluation. Combining simplicity-of-use with efficient computational capabilities, the GDP design system should prove useful in numberous engineering applications.
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    URL: http://dx.doi.org/10.1007/BF01914788
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    Call for papers (1989)
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    The visual computer 5 (1989), S. 327-327 
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    ISSN: 1432-2315
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01914792
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  • 42
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    Skeleton-based image warping (1989)
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    The visual computer 5 (1989), S. 95-108 
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    ISSN: 1432-2315
    Keywords: Image processing ; Geometric transformation ; Image reparameterization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Image warping refers to the 2D resampling of a source image onto a target image. Despite the variety of techniques proposed, a large class of image warping problems remains inadequately solved: mapping between two images which are delimited by arbitrary, closed, planar curves, e.g., handdrawn curves. This paper describes a novel algorithm to perform image warping among arbitrary planar shapes whose boundary correspondences are known. A generalized polar coordinate parameterization is introduced to facilitate an efficient mapping procedure. Images are treated as collections of interior layers, extracted via a thinning process. Mapping these layers between the source and target images generates the 2D resampling grid that defines the warping. The thinning operation extends the standard polar coordinate representation to deal with arbitrary shapes.
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    The electronic design notebook: Performing medium and processing medium (1989)
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    The visual computer 5 (1989), S. 214-226 
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    ISSN: 1432-2315
    Keywords: Image performance ; Computer graphics ; Design notebook ; Agile interface ; Visual language
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The traditional “Engineer's Notebook” is a volume of bound paper pages. This archaic system is still the medium of choice for mechanical engineers during the conceptual phase of design. In making this choice, designers are taking aperformer's view, choosing freedom and agility in the initial making of drawings over processing power. The paper notebook allows the designer to quickly write and draw whatever she or he desires. During conceptualization, a designer is functioning as a performer, like a musician. And also like a musician, her instrument must be agile or the performance will be cramped and ideas lost. But the agility of Computer Aided Design systems has been neglected in favor ofprocessing power — the ability to do something with the drawings in addition to just making them. Described in this paper isvmacs, a prototypeElectronic Design Notebook which combines the capabilities of performing medium and processing medium.
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    Editorial (1989)
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    The visual computer 5 (1989), S. 263-263 
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    ISSN: 1432-2315
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01914784
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    Feature based object decomposition for finite element meshing (1989)
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    The visual computer 5 (1989), S. 291-303 
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    ISSN: 1432-2315
    Keywords: Decomposition ; Finite element ; Geometric modeling ; Solid modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Performing a finite element analysis requires overlaying an object with a mesh of varying density based on the expected stress levels within the part. Attempts have been made in the past to automat the finite element meshing procedure. The method presented here is “intelligent” in the sense that it examines the complete part for potential stress gradients and decomposes the part into hexahedral regions according to the geometry gradients in the part. High geometry gradients are regions of high curvature, especially edges. The algorithm segregates high gradient features into isolation volumes. It then continues to decompose each isolation volume dependent on the particular geometry contained in the feature. The result is a set of hexahedral bricks suitable for passing to an automatic meshing routine.
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    New exocrine glands in the legionary ants of the genus Leptanilla (Hymenoptera, Formicidae, Leptanillinae) (1989)
    Springer
    Zoomorphology 108 (1989), S. 255-261 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper reports the results of the first detailed study of the morphology of exocrine glands in two species of the ant subfamily Leptanillinae. Workers of Leptanilla escheri and L. japonica possess a large, unpaired sternal gland in the VIIth abdominal sternite, and an hypertrophied poison gland which is surrounded by a massive muscle layer. The sternal gland is absent in the queen of L. japonica, and the poison gland is highly degenerated. The queen is, however, endowed with a series of large, paired, intersegmental tergal and sternal glands, which occur between the IVth through the VIIth segments. The queen also posseses large spiracular plate glands.
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    URL: http://dx.doi.org/10.1007/BF00312158
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    Functional associations between the cribellum spinning plate and capture threads of Miagrammopes animotus (Araneida, Uloboridae) (1989)
    Springer
    Zoomorphology 108 (1989), S. 263-267 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Uloborid cribellar silk consists of torus-shaped puffs. In Miagrammopes animotus the width of these puffs is about 36% that of the cribellum of the spider and shows a 2.3-fold increase in surface area during development. The cribellar spigot number increase 5.7-fold during development, although, relative to spider mass, it decreases by 34%. Cribellum width is the best predictor of both cribellar silk puff width and length and is as good a predictor of puff surface area as is cribellum surface area. Relative to cribellum width, the length of the calamistrum comb responsible for drawing fibrils from the cribellum changes little during development. The attachment points of cribellar silk to a parallel frame thread become more widely spaced during development, although the number of puffs they delimit changes little.
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    Microscopical aspects on symbiosis of Spongilla lacustris (Porifera, Spongillidae) and green algae (1989)
    Springer
    Zoomorphology 108 (1989), S. 291-296 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When growing in the sunlight, some specimens of Spongilla lacustris are coloured green due to the presence of symbiotic unicellular chlorellae. The algae live inside most sponge cells. The chlorellae were extracted from green sponges, cultivated, added to algae-free sponges and fixed after different incubation times. In this way the uptake of the algae, their distribution and their final whereabouts in the mesenchymatic cells could be followed by in vivo microscopy, phase-contrast microscopy and electron microscopy. A few minutes after addition, the chlorellae can be found inside the choanocyte chambers. Here they are taken up by the cell bodies and collars of the choanocytes. Pinacocytes are also involved in the uptake. The distribution of algae results from a specific transmission from the donor cell to the receiver cell. The chlorellae are not released from their host vacuoles until they are extensively enclosed by the cell taking them up. Six hours after addition, all sponge cells contain algae except granulocytes, microscleroblasts, the pinacocytes of the peripheral rim region and those of the pinacoderm. The chlorellae are able to divide inside the sponge cells.
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    Inhibitory effects of undecayed wood and the detection of Postia placenta using the enzyme-linked immunosorbent assay (1989)
    Springer
    Wood science and technology 23 (1989), S. 13-20 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Pulverized, undecayed wood was shown to be, in general, inhibitory to attempts to use enzyme-linked immunosorbent assay (ELISA) in detecting and quantifying the decay fungus Postia placenta (Fr.) M. Lars. et Lomb. Nevertheless, the assay was still able to adequately detect the presence of P. placenta at a greater than 1: 10,000 dilution even in the presence of 0.1 g/ml spruce wood. The use of polyvinyl pyrrolidone did not improve ELISA performance but adsorbent polystyrene had some effect on the assay sensitivity.
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    Effects of water vapour heating on structure and properties of cork (1989)
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    Wood science and technology 23 (1989), S. 27-34 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The effects of heating cork in water vapour at 100°C and 300°C are studied and compared with those produced by heating in air at the same temperatures. Dimensional and mass changes were measured and radial compression curves were obtained following various treatments. The 300°C treatments originate a straightening of the originally corrugated cell walls, while the cell wall material undergoes thermal degradation. Larger swellings and larger mass changes are observed in the treatments in water vapour as compared to those in air. The 100°C treatments do not induce degradation and produce reversible changes in technological properties which are simply due to differences in the water content.
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    Modelling longitudinal elastic an shrinkage properties of wood (1989)
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    Wood science and technology 23 (1989), S. 55-63 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A model was developed for estimating elastic and shrinkage properties of a softwood cell wall from the properties of its polymeric constituents: cellulose, hemicellulose and lignin. The theory of composite materials was used. Based on a literature survey, models of latewood, earlywood and compressionwood of a softwood cell wall structure were made. The model takes into account the helical winding of the microfibrils in the cell wall and it estimates the behaviour of a balanced laminated double-cell wall in which rotation is restrained by adjacent cells. The calculated elastic and shrinkage properties were compared with earlier test results and good agreement was found.
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    Impact of water storage on mechanical properties of spruce as detected by ultrasonics (1989)
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    Wood science and technology 23 (1989), S. 35-42 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The impact of a five months water storage together with a bacterial treatment, on the mechanical properties of spruce is analysed by ultrasonic waves. The Bacillus subtilis is used to improve the permeability of spruce sapwood. The attack of bacteria on the torus of aspirated pits is expected to lead to a better transport of preservative liquids. The elastic constants were calculated through ultrasonic velocities which were measured at different types of specimens. The results were compared with the constant EL as determined by a static bending test. The calculated loss of strength seems to be negligible but variations in the elastic properties of anatomical plaines consisting radial axes, can be well predicted.
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    Relationship between degradation of wood and production of H2O2-producing or one-electron oxidases by brown-rot fungi (1989)
    Springer
    Wood science and technology 23 (1989), S. 1-12 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The one-electron oxidation activity of brown-rot fungi was determined by measuring ethylene production from KTBA. Ethylene production was related to degradation of lignin, cellulose, and wood itself. Extracellular protein that catalyzed oxidation of KTBA was isolated from wood-containing cultures. This protein required H2O2 for KTBA oxidation. It was also found to oxidize NADH, producing H2O2 via $$O_2^{\bar \cdot } $$ in the presence of O2. The protein showed little phenol-oxidase activity under conditions giving high activity against KTBA. The results indicate that partially reduced oxygen may play a role in the initial degradation of the cellulose and lignin in wood in cultures of brown-rot fungi.
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    Calorific value variation in coconut stem wood (1989)
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    Wood science and technology 23 (1989), S. 21-26 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Fuelwood quality parameters such as calorific value, siliceous matter and basic density of coconut stem wood were determined. The material examined was from non-diseased senile palms of age around 70 years and root-wilt diseased palms of age group 55–65 years, 35–45 years and 15–25 years. Average calorific value of coconut stem wood in air-dry condition was found to be about 16.3 MJ/kg and it compares fairly with that of hardwoods. A highly positive correlation (r=0.96) was obtained between density and calorific value per unit volume. Also, a highly negative correlation was obtained between siliceous matter and calorific value. Upper half of the mature and over-mature palms and full length of young palms which have been affected by root-wilt disease could be used as a fuelwood of adequate heating value or converted into charcoal.
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    Crack propagation in mixed mode in wood: a new specimen (1989)
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    Wood science and technology 23 (1989), S. 43-53 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary For studies on wood structures it is important to have a reliable specimen for mixed mode loading (I+II) of a crack. A new type of specimen derived from the compact tension shear (CTS) specimen proposed by Richard for isotropic materials has been studied. A finite element modelization for pine (Pinus pinaster) gives calibrations in the RL, TL and TR directions. Fracture experiments show a fair agreement between stress intensity factors obtained by calibrations and by the compliance method.
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    Segmented models for stress-strain diagrams (1989)
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    Wood science and technology 23 (1989), S. 65-73 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Tension and compression stress-strain data from tests of wood specimens were mathematically described by 2- or 3-segment models, respectively. Three or four parameters are required by the segmented models, but these are easily obtained from regression analysis of the digitized data. One required parameter is Young's modulus. The model parameters varied with moisture content, and it was possible to regenerate typical stress-strain diagrams at a variety of moisture levels for use in a finite-element program. This form of analysis makes it possible to demonstrate statistically that wood stress-strain diagrams have an initial linear segment, and that the stress-strain diagrams are not entirely curvilinear as some have proposed.
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    Analysis of birch wood lignin by oxidative degradation (1989)
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    Wood science and technology 23 (1989), S. 75-83 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The lignin in birch wood has been subjected to analysis by oxidative degradation after milling of wood samples in a Wiley mill and in a rotatory ball mill. For comparison milled wood lignin from birch has also been analysed. It was found that the type of milling affects both the total yield of degradation acids and their relative frequency of occurrence. These findings are interpreted as being due to a cleavage of aryl ether linkages during the milling procedure. The oxidative degradation analysis gave rise to a total of 30 different acids which were tentatively identified on the basis of their mass spectral fragmentation patterns. Among the acids some were found having either a phenoxyacetic acid or a phenoxypropionic acid structure. The possible origin of these is discussed.
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    Crystals of cellulose grown from TFA solution (1989)
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    Wood science and technology 23 (1989), S. 85-94 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Crystallization experiments starting from highly concentrated solutions of cellulose in trifluoroacetic acid (TFA) resulted in white crystalline particles with diameters of as much as 0.5 mm. The plate-like particles consist of lamellae arranged perpendicular to the surface. The lamellae are grown from thin scale-like platelets showing clear diffraction reflexes and an internal parallel structure. Parallel structures were also detected in partially hydrolyzed cellulose. It is concluded that cellulose chains of low DP tend to rearrange themselves by a side by side accumulation of extended molecules.
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    Predicting the load capacity of wood composite I-beams using the tensor polynomial strenght theory (1989)
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    Wood science and technology 23 (1989), S. 109-121 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The tensor polynomial strength theory for anisotropic materials was coupled with finite-element analyses to predict the ultimate load capacity of several wood-composite I-beams. Small-specimen tests with the constituent materials provided elastic constants for the finite-element computations and ultimate strengths for development of strength tensors. Ultimate load capacity, failure modes, and sites of failures in wood composite I-beams were predicted. Analytical results were in excellent agreement with data from full-scale I-beam tests and demonstrated the influence of web joints and material strengths on failure characteristics.
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    Effect of curing heat, alkali and cement set in cement particleboard on the visco-elastic properties of chip mattresses (1989)
    Springer
    Wood science and technology 23 (1989), S. 131-138 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The aim of this study was to investigate the influence of temperature, alkali and cement set on the visco-elastic properties of chip mattresses made in cement and calcium hydroxide, respectively. Two temperatures were used, room temperature and 78°C, believed to represent the limits of the range of temperatures experienced industrially in the manufacture of cement composites. Calcium hydroxide and cement were used to find the effect of alkali and the effect of cement set. The temperature affected the visco-elastic properties by increasing the unrecovered strain, and alkali also increased the unrecoverable strain. The effect of heat and alkali increased when the two were used in combination. In cement chip composites, the effect of cement set was the most dominant that the effect of heat and alkali could not be observed.
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    Relationship of capillary pressure and water saturation in wood (1989)
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    Wood science and technology 23 (1989), S. 139-150 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary An understanding of free water movement in the gross capillary structures of wood requires a knowledge of capillary pressure. A method is described whereby the relationship between capillary pressure and water saturation can be determined under decreasing saturation. Water-saturated core samples of wood were centrifuged at increasing rates, and the average saturation was measured at each rate. The results indicate that the degree of saturation, and therefore the moisture content, at a given capillary pressure varied greatly with different woods. Theoretically, all free water that is held in the macroscopic capillaries can be removed by the action of centrifugal force. However, in some woods, the capillary pressure curve becomes asymptotically vertical at moisture contents above the fiber saturation point (30 percent MC), indicating that free water still remained in the wood. It is postulated that the transport of free water is affected not only by capillary pressure considerations but also by the rate of drainage as influenced by surface roughness along the lumen walls.
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    Book reviews (1989)
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    Wood science and technology 23 (1989), S. 191-192 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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    URL: http://dx.doi.org/10.1007/BF00350941
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    The reflectance method for testing the effectiveness of fungicides against surface mould growth on materials: I. Wood (1989)
    Springer
    Wood science and technology 23 (1989), S. 179-189 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary An instrumental method for the measurement of the toxic value of preservatives against mould fungi on wood and wood products was tested as an alternative to the widely used visual method with its inherent disadvantage of subjectivity. The new criterion of effectiveness to be used was light reflectance as measured by either the Zeiss photometer (Leukometer) or the Zeiss spectrophotometer (Spekol 10) fitted with the Rd/0 reflectance adapter. Sodium pentachlorophenate and the WR-3 (quaternary ammonium compound), applied to pine and birch wood samples were tested for effectiveness against five species of fungi capable of causing surface moulding. Although the reflectance method was more laborious, the results obtained seem to be better than those obtained by the visual method. The proposed method appears to be of practical value in eliminating difficulties involved in the subjective assessment of both the intensity of surface growth and the effectiveness of the wood preservatives themselves.
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    Effect of wilt disease and age on the strength properties of coconut palm stem wood (1989)
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    Wood science and technology 23 (1989), S. 205-209 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Static bending test and compression test parallel to the grain were conducted on coconut stem wood from non-diseased over-mature palms and wilt-diseased palms of different age groups; properties like fibre strength at limit of proportionality (FSLP), modulus of rupture (MOR), modulus of elasticity (MOE), work to maximum load (WML) and maximum crushing strength (MCS) were determined. Wilt disease did not have any adverse effect on strength properties. Though, in general, age did not affect the strength prperties significantly, over-mature palms had significantly higher MOE values than lower age palms. Strength properties of coconut wood from over-mature palms compare quite well with that of other structural timbers. Stem wood from wilt-diseased palms, of adequate density, can also be used for construction purposes.
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    Electron beam damage during testing of wood in the SEM (1989)
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    Wood science and technology 23 (1989), S. 211-214 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Specimens of spruce (Picea abies) were taken to compression failure in the SEM while the backscattered electron imaging was used. Control specimens were taken to failure with no beam exposure. Failure morphology was studied using the secondary electron imaging. Wood exposed to the electron beam during testing showed a glassy fracture, while wood exposed to high vacuum but not to the electron beam showed a ductile fracture. There was found no evidence of any significant brittleness for unexposed wood at different moisture content levels. Although electron beam damage may be reduced, it can never be avoided. Caution is therefore to be exercised in the interpretation of results of compression tests in the SEM.
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    Mechano-sorptive creep mechanism of wood in compression and bending (1989)
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    Wood science and technology 23 (1989), S. 215-227 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A model is introduced which links the mechano-sorptive behaviour of wood subjected to moderate and high compression or bending stresses parallel to grain to the formation of slip planes in the cell wall. Slip plane formation is dependent on the breaking of hydrogen bonds, which process is directly related to the amount of moisture change. The dramatic change of microfibril orientation in slip plane zones cause an increase of the longitudinal shrinkage/swelling and a decrease of the modulus of elasticity. These features of slip plane formation account for both the magnitude and the oscillation of the excessive mechano-sorptive creep associated with compression and bending parallel to grain. A summary is given of the characteristics of the mechano-sorptive effects, and the model is discussed in the light of these effects.
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    Theoretical models for creep slip of nailed joints between wood and wood-based materials (1989)
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    Wood science and technology 23 (1989), S. 237-249 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Applying modern methods of analyzing floor, wall, and connection subsystems in light-frame wood buildings requires information on the stiffness of nailed joints under long-term loads. Because this information can best be derived by testing nail-joint specimens under constant loads, theoretical procedures were developed that use test data for constant loads to predict stiffness under variable in-service loads; five nonlinear, viscous-viscoelastic models were develpoed on the basis of existing formulations of creep and mechanisms of load transfer between nails and wood. The models incorporated the modified superposition and strain-hardening principles in describing responses to discrete or continuous loading functions. Tests have shown that the models closely predict creep slip of typical nailed joints.
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    A vapour phase preservative treatment of manufactured wood based board materials (1989)
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    Wood science and technology 23 (1989), S. 273-279 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The preservative treatment of four different wood based board materials using an esterified borate applied in the vapour phase was investigated. Under optimum conditions complete impregnation via the board faces was achieved in all boards treated. Board moisture content and treatment time had a major influence on retention and depth of penetration of the borate vapour.
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    What we do and what we need to do in timber engineering (1989)
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    Wood science and technology 23 (1989), S. 289-293 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00353243
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    Axial pattern of whole-ring density variation in blue pine (Pinus wallichiana A. B. Jackson) (1989)
    Springer
    Wood science and technology 23 (1989), S. 295-298 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Whole-ring density in blue pine (Pinus wallichiana A. B. Jacks.) decreases from base to the top of tree in rings numbered from bark as well as in rings numbered from pith. It is negatively and significantly correlated with percentage height. General pattern remains the same, when sampling is done internodally or when it is done at fixed positions (percentages) along the boles of blue pine trees. Density at the breast-height level is more than that at the top of tree and the breast-height values are positively and significantly correlated with that of total tree values.
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    Thermal treatment of wood: analysis of the obtained product (1989)
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    Wood science and technology 23 (1989), S. 303-310 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Physicochemical analyses were performed on samples of torrefied wood obtained at various temperatures. The chemical structure of wood was strongly altered by this process; a reactional mechanism for this is proposed in this paper. The influence of temperature and the duration of heating were compared to find the more important factors in the process. We found that these two parameters widely affected the nature of the final product. The 3.D. surfaces enabled us to predict the operating conditions which were essential to obtain a definite product with the maximum efficiency.
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    Creep of four tropical hardwoods from Cameroon (1989)
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    Wood science and technology 23 (1989), S. 335-341 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The knowledge of the behaviour of wood over time is important in the design of timber structures. This study, which is part of a program to better understand the behaviour of tropical woods, aims at showing the effect of creep in wood. Observations were made on the development of the deflection in a uniformly stressed beam under controlled temperature and humidity conditions. The results obtained show that for stresses not greater than 35% of the stress at failure, the behaviour of the species tested is linear. In these cases, the total relative creep is not more than 35%. Similar results have been obtained for four cameroonian species: Azobe, Tali, Sapelli and Movingui.
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    Linearity and non-linearity in mechano-sorptive creep of softwood in compression and bending (1989)
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    Wood science and technology 23 (1989), S. 323-333 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Non-linearity of softwood in axial mechano-sorptive creep during moisture cycling can be characterised as departure from linear behaviour. Linear behaviour is shown by experimental measurement to be a gradual approach to a creep limit with exponentially decreasing increments of compliance, Ji, per moisture cycle, when tested under a constant stress. On the other hand, when the stress is progressively increased by a small increment Δσ after each moisture cycle, the compliance increments will progressively increase, having a value of $$\Delta \sigma \sum\limits_1^n {{\text{J}}_{\text{i}} }$$ , where n is the cycle number. By subtracting one compliance increment from the succeeding one, the value of Δσ Ji can be obtained. Analysis of experimental results in bending tension and compression showed that the compression test pieces departed from linearity at total strains around 0.14% to 0.15%, the bending test pieces showed slight evidence of non-linearity at about the same strain, whilst the tensile pieces were approximately linear up to 0.18% strain.
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    Characterization of the ashes of Nigerian red and white mangrove woods (1989)
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    Wood science and technology 23 (1989), S. 357-360 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary An investigation of the analytical characterization of ashes of Nigerian red and white mangrove woods was carried out. The ashes obtained from the woods were subjected to intense heating in water to extract the chemical constituents. Some quantitiy of rock salt was also dissolved in water and analysed. The solution obtained from the ashes were differently analysed for K+, Na+, Ca2+, Mg2+, Cl−, SO4, PO4, NO3 and total solid. The pH of each sample solution was measured. Various concentrations of these cations and anions were obtained and they were found in each case to be more than those obtained from rock salt. Solutions obtained from the ashes of red and white mangrove woods have wide applications particularly in Nigeria as tasty food additive and in softening and accelerating the cooking time of yam, plantain and beans in particular.
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    Production of particleboard with steam-injection (1989)
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    Wood science and technology 23 (1989), S. 361-369 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The temperature behavior of the particle mat during hotpressing and steam-injection pressing was investigated under various conditions: in the case of hot-pressing, it required about 3 and 11 minutes to increase the temperature to 100°C at the middle layer of a mat with a thickness of 20 and 40 mm, respectively. With an increase of moisture content, the time necessary for the middle layer to reach 100°C tended to shorten, whereas the time to maintain a constant temperature (about 100°C) was prolonged. The temperature in the middle layer of a mat with a higher moisture content in the face layers increased at a rate four times that of a mat with a uniform distribution of moisture content. In the case of steam-injection pressing, the temperature in the middle layer of mats with a thickness of 20 and 40 mm increased beyond 100°C at the moment of steam-injection, and maintained a constant level during steam-injection. After stopping steam-injection, the temperature decreased to about 100°C, and then started to rise gradually again. With the steam-injection process, the moisture content of the mat did not increase as much as usual, and the rates of temperature increase in the middle layers of mats with different thickness, moisture content and density were similar. After the stem-injection had been stopped, the temperature of dry mats kept rising, whereas that of mats with a moisture content of 11% decreased to 100°C and then increased gradually. When the steam pressure for injection was higher, the vapor pressure or temperature at the middle layer increased to a higher level.
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    Grading of construction timeber by ultrasound (1989)
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    Wood science and technology 23 (1989), S. 95-108 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The resistance of spruce beams was characterized with the aid of nondestructive ultrasonic measurements. The modulus of elasticity and the modulus of rupture in flexure for beams of commercial sized section can be estimated by observing the speed of propagation of a longitudinal wave applied to the longitudinal axis of the beam. The use of simple ultrasonic equipment and two experimental transducers (in direct and dry contact) permit measurements to be performed in industry. The technique constitutes the basis of an objective concept for classification of sawn timber guaranteeing a better reliability and profitability with regard to the visual grading rules used in Western Europe.
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    Studies on the delignification of spruce wood by organosolv pulping using SEM-EDXA and TEM (1989)
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    Wood science and technology 23 (1989), S. 123-130 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Samples of spruce wood derived from various stages of organosolv pulping were studied by SEM-EDXA and TEM. During the first stage (methanol-water) the lignin content of the secondary walls decreased slowly, whereas in the compound middle lamellae only the reactivity of lignin increased. During the subsequent stage (methanol-NaOH) the delignification proceeded fast in both layers but the residual lignin content in the compound middle lamellae remained higher than in the secondary walls.
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    Interactions between Scytalidium species and brown- or white-rot basidiomycetes in birch wood (1989)
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    Wood science and technology 23 (1989), S. 151-161 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Growth and subsequent decay by seven basidiomycetes in birch wood blocks was inhibited by three Scytalidium isolates. Scytalidium initially colonized the surface of the blocks and gradually overgrew the basidiomycetes. In individual wood blocks from 11 Scytalidium-basidiomycete paired treatment combinations, the basidiomycete was not inhibited throughout the entire wood block. These wood blocks demonstrated interspecific interactions and antagonism between the different fungi. The white-rot fungi responded to isolates of Scytalidium by occluding xylem cells with masses of hyphae, forming pseudosclerotial plates in the zone of initial interaction. Scytalidium appeared to gain access into portions of wood colonized by the basidiomycetes only after substantial decay had resulted by the wood decay fungus.
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    Effect of Coriolus versicolor on physico-chemical properties of Eucalyptus globulus wood (1989)
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    Wood science and technology 23 (1989), S. 163-169 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The purpose of this study was to determine the progressive changes in physical and chemical properties of Eucalyptus globulus wood under the action of a representative white rot fungus, Coriolus versicolor. Observations concerning the nature and relative effects on weight loss, hot water solubility, 1% sodium hydroxide solubility, Klason lignin, holocellulose, intrinsic viscosity and degree of polymerisation of holocellulose, pentosans, methoxyl value, neutral sugar composition and nitrobenzene oxidation products are discussed.
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    Lectin from the trunk of Sophora japonica (1989)
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    Wood science and technology 23 (1989), S. 171-178 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Lectin was purified from the bark of Sophora japonica trunk by a simple method, affinity chromatography on acid-treated agarose; the yield was about 27% of the total sap proteins. Its molecular weight was 135,000±5,000 shown by using gel filtration, similar to that of the seed lectin of this species. When analyzed by using polyacrylamide gel electrophoresis (PAGE) under acidic and basic conditions, the lectin showed multiple bands. These patterns were different from those obtained with the seed lectin of the same tree. The trunk lectin had a broader specificity for the blood types than the seed lectin. These observations demonstrate that the trunk and the seed lectins from the same tree are different molecular species.
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    Permutation procedures as a statistical tool in wood related applications (1989)
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    Wood science and technology 23 (1989), S. 193-204 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Two variations of a class of permutation tests termed Multi-Response Permutation Procedures (MRPP1 and MRPP2) and the classical two-sample, two-sided t test were used to evaluate 72 data sets from tests on wood joints made with elastomeric construction adhesives. In all cases, the probability levels obtained from MRPP2 and the two-sample t test were nearly identical. This result stems from the fact that the test statistics of these two tests are theoretically equal. However, the underlying distributions of these two statistics are different. In several of the 72 comparisons, conflicting inferences about population differences were reached using MRPP1 and MRPP2. The results indicated that when the two data sets closely approximated a normal distribution and equal variances occurred, the MRPP2 (the permutation version of the t test) was the more optimal test. When validly-obtained extreme points were present, then the assumption of normality was not reasonable and MRPP1 was superior.
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    The measurement of tensile creep in thin wood strips (1989)
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    Wood science and technology 23 (1989), S. 229-235 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Tensile creep of 100 μm thick wood strips cut parallel to the grain was measured using a high resolution high accuracy creep apparatus. Rigorous attempts were made in both design and use of the apparatus to reduce errors to a minimum: the standard deviation of the random errors about a smoothed curve was assessed as 0.34 μm. By comparing elongation of strips under load with control strips at zero load viscous and visco-elastic elongation may be accurately measured.
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    Evaluation of “three-variable” models for the prediction of equilibrium moisture content in wood (1989)
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    Wood science and technology 23 (1989), S. 251-257 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Four sorption isotherm models that express moisture content as a function of both relative humidity and temperature were evaluated by fitting them to a set of sorption data between 21.1 and 71.1°C, with the help of a nonlinear curvefitting program. All of them predicted the sigmoid shape of the sorption isotherms and the shift towards the x-axis as the temperature increased. The calculated root mean square error was used as an indication of the goodness of the fit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367738
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  • 84
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    Book review (1989)
    Springer
    Wood science and technology 23 (1989), S. 280-280 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367741
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  • 85
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    Modelling the process of moisture absorption in three dimensions by wood samples of various shapes: cubic, parallelepipedic (1989)
    Springer
    Wood science and technology 23 (1989), S. 259-271 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Modelling the process of absorption of moisture by wood samples of various shapes and dimensions: cube and parallelepipedes, has been studied. The mathematical model is based on numerical method with finite differences, and takes into account all the facts: the external resistance with the coefficient of moisture transfer at the atmosphere-wood interface, the internal resistance with the diffusion of moisture within the wood. The problem is rather complex, because the rate of diffusion varies with the direction chosen in the wood, and because of the concentration-dependent diffusivities. Not only the model is able to obtain the kinetics of absorption of moisture in good agreement with experiments done with samples of various shapes, but it is also capable of calculating the profiles of concentration of moisture developed within the sample, and so affording a further insingt on the process of moisture absorption.
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    URL: http://dx.doi.org/10.1007/BF00367739
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  • 86
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    Chemical and physical changes required for producing dimensionally stable wood-based composites (1989)
    Springer
    Wood science and technology 23 (1989), S. 281-288 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary High temperature (240°C) contact treatment was shown to be a very effective method of stabilizing panels bonded with heat resistant adhesive. Chemical analyses of post treated boards indicate that chemical changes of the wood components due to contact heat treatment were negligible. The results support the concept that high temperature post treatment of boards at temperatures above the softening points of lignin and carbohydrate components, caused plastic flow in situ which relieved internal stresses built up during hot pressing. Consequently, springback in wood-based composites diminished leaving panels much more stable than conventional products. Also, dimensionally stable wood-based composites had a better inherent ability to withstand severe exposure conditions than the regular boards.
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    URL: http://dx.doi.org/10.1007/BF00367742
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  • 87
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    Modification of the latex paint infusion technique for the determination of vessel-length in hardwoods (1989)
    Springer
    Wood science and technology 23 (1989), S. 299-302 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The problem of vessel length determination in hardwood trees has been approached in many ways by various workers. The paint infusion technique was utilized in a research programme investigating the subject of vessels of New Zealand beech (Nothofagus) stem sapwood. Two different models of stainless steel paint applicator were used: (a) the horizontal “T” shaped applicator and (b) the new vertical “Y” joint applicator. Applicator construction is discussed. The techniques are modifications of the Zimmermann and Jeje (1981) latex paint infuction method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00353245
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  • 88
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    On the origin of growth stresses in trees (1989)
    Springer
    Wood science and technology 23 (1989), S. 311-322 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary The mechanics of growth stress generation in a tissue of developing wood cells is studied by means of a continuum-mechanical model which assumes that the stresses which accumulate in the cells are induced by growth strains in the newly formed cell wall increments as they are laid down. The feasibility of the model is examined by using cell parameters both anatomical and physical to predict the variation of growth stresses with microfibril angle. In particular the measured change from tensile to compressive stresses with increasing microfibril angle for conifers is compared with the results predicted by the model.
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    URL: http://dx.doi.org/10.1007/BF00353247
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  • 89
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    Characterization of depolymerized cellulosic residues (1989)
    Springer
    Wood science and technology 23 (1989), S. 343-355 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary It is known that dilute acid hydrolysis of cellulose results in yields not exceeding 60–65% of the potential glucose. All the models presented in the literature are based on the sequence cellulose→glucose→degradation products. The underlying assumption of this sequence is that the unconverted cellulose retains its chemical integrity with the extent of the hydrolysis reaction. In this paper we show that the unconverted cellulose is indeed modified during the hydrolytic treatment and cannot be chemically identified as cellulose as the reaction proceeds. This obviously limits the glucose yields and results in a major modification of the reaction sequence via dilute acid hydrolysis. Thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and diffuse reflectance infrared (DRIFT) have been used to study the structural and chemical changes of the cellulosic residues as a function of the extent of hydrolysis.
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    URL: http://dx.doi.org/10.1007/BF00353250
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  • 90
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    Book reviews (1989)
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    Wood science and technology 23 (1989), S. 370-370 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00353253
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  • 91
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    Adhesive/fibre interaction in medium density fibreboard (1989)
    Springer
    Wood science and technology 23 (1989), S. 371-380 
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    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Qualitative and quantitative Jamin-Lebedeff interference microscopy was used in combination with embedding and thin sectioning to study the interaction between phenol-formaldehyde or urea-formaldehyde resins, and the fibre surface of medium density fibreboard from a wide range of commercial sources. Interference microscopy was used to measure the refractive indices of both resins to enable positive identification of resin within the board. Contact angle between resin and fibre surface was measured to provide an estimate of the degree of wetting of the fibre. Phenol-formaldehyde resin showed significantly lower contact angles and therefore better fibre wetting when compared with urea-formaldehyde. Phenol-formaldehyde tended to form a thin layer on the fibre surface while urea-formaldehyde tended to form large compressed droplets or patches of resin between the fibres. It is suggested that by improving the wetting properties of urea-formaldehyde resin, significant improvements in internal bond strength may be achieved.
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    URL: http://dx.doi.org/10.1007/BF00353254
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  • 92
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    Germ cell cluster in the panoistic ovary of Thysanoptera (Insecta) (1989)
    Springer
    Zoomorphology 108 (1989), S. 309-313 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Germ cell clusters are found in the germarial region of ovarioles of Parthenothrips dracenae. Cluster mitoses are synchronized, at least initially. The intercellular bridges are filled with fusomal material, which can fuse to form polyfusomal aggregates which in turn form small rosettes. All cells develop into oocytes. Oocytes become isolated by a secondary detachment process. Intercellular bridges, together with fusomal material and cell membranes, survive for some time as isolated bodies. Phylogenetic consequences are discussed. The data provide strong evidence for a secondary panoistic ovary in thysanopterans, since cluster formation in ovaries of primary panoists has not been shown.
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    URL: http://dx.doi.org/10.1007/BF00312163
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  • 93
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    Larvale Nierenorgane bei Lepidochiton cinereus (Polyplacophora) und Aeolidia papillosa (Gastropoda) (1989)
    Springer
    Zoomorphology 108 (1989), S. 297-307 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Larvale Protonephridien werden bei L. cinereus und A. papillosa auf ultrastruktureller Ebene beschrieben. Die Organe bestehen jeweils aus einer Terminalzelle, zwei (A. papillosa) oder mehreren (L. cinereus) Kanalzellen und einer Nephroporuszelle. Die Terminalzelle ist multiciliär, besitzt Mikrovilli und ein geschlitztes cytoplasmatisches Element, das bei L. cinereus lappenförmig, bei A. papillosa als Hohlzylinder ausgebildet ist. Dieses cytoplasmatische Element fungiert als Trägerstruktur der Filtrationsbarriere (ECM bzw. Diaphragmata) und ist durch Desmosomen mit der folgenden Kanalzelle verbunden. Aufgrund homologer Übereinstimmungen der hier beschriebenen Protonephridien mit entsprechenden Organen anderer Bilateria sind larvale Protonephridien im Grundmuster der Mollusken anzunehmen.
    Notes: Summary Protonephridia are described at the electron microscopical level in the larvae of L. cinereus and A. papillosa. These nephridial organs are composed of one terminal cell, two (A. papillosa) or several (L. cinereus) duct cells, and one nephridiopore cell. In each case, the perikaryon of the terminal cell bears cilia, microvilli and a slashed cytoplasmic element (like a lobe in L. cinereus; like a hollow cylinder in A. papillosa), which functions as the supporting structure of the filtration barrier (ECM or diaphragm) and is desmosomally connected to the adjacent duct cell. Developmental aspects of the organs are described for L. cinereus. The description of protonephridia in larvae of a polyplacophoran permits a reevaluation of the nephridial design in larvae of molluscs: because of homologous correspondences to the protonephridia of other members of the Bilateria, larval protonephridia are postulated for the ground pattern of molluscs.
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    URL: http://dx.doi.org/10.1007/BF00312162
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  • 94
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    Comparative mechanics of filter feeding in Anas platyrhynchos, Anas clypeata and Aythya fuligula (Aves, Anseriformes) (1989)
    Springer
    Zoomorphology 108 (1989), S. 269-290 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The straining of seeds ranging in size from 0.01 to 4.6 mm was investigated in the filtering mechanisms of three anseriform species, Anas platyrhynchos, Anas clypeata, and Aythya fuligala. The morphology of the filtering mechanisms was studied by dissection and from microsections. The kinematic work envelope of the beaks was measured by stereotactic manipulation. The actual beak kinematics were analyzed by calculating the changes of the mouth volume from computer simulations and comparing the results with the amounts of water expelled. The performances of the filter and the water pump were measured with special collection boxes. The influence of the lamellae was estimated by removing them in whole or in part and measuring the performances again. The results show that if the size of the strained seeds increases, the gapes and amplitudes also increase (cf. bill rotations). Beak rotation is elevated for small kernels, even more elevated for slightly larger ones, but depressed for large kernels. However, neither frequencies nor phase shifts change between different moving elements. Simulation of these data by stereotactic manipulation of fresh material and by measuring gape sizes and mesh widths shows that the beak kinematics during straining keep mesh widths and gapes carefully adjusted to the seed size. The pumping and the filtering mechanisms influence each other mutually in setting boundary conditions on mouth kinematics. Beyond a certain kernel size, the necessity for mesh-width control sets a boundary on the increase of the water flow. Conversely, phase shifts, frequency changes and change of lingual amplitudes were restricted by the pumping mechanism. Drastic shortening of either dorsal mandibular or maxillary lamellae in Anas platyrhynchos and Aythya fuligula does not effect either the filter performances, the pump performances, or the beak kinematics, but these modifications do change the performances in Anas clypeata. The usually accepted assumption concerning food sieving was thus verified for Anas clypeata and falsified for the other two anseriform species. Therefore, a vortex model in addition to the sieving model, was developed, based on the assumption that local vortices cause inertia of particles so that small kernels are filtered by centrifugation and translation out of the main water flow. Combined effects of sieving and centrifugation occur when larger kernels are filtered. The kinematics of the filtering mechanism are highly flexible; therefore, a wide tolerance for seed sizes exists. However, the morphology of the filtering mechanism differs in the three species. Testing whether the anseriform filter mechanism is so plastic that the mechanism in each species has developed in such a way that the staple food is gathered most economically has shown that filtering of the staple food does indeed occur at the most efficient levels of maxillary rotation.
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    URL: http://dx.doi.org/10.1007/BF00312160
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    Ultrastructural investigations on the nuchal organ of the protandric polychaete, Ophryotrocha puerilis (Polychaeta, Dorvilleidae) (1989)
    Springer
    Zoomorphology 108 (1989), S. 315-322 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nuchal organs of the protandric hermaphrodite Ophryotrocha puerilis were studied by electron microscopy. Ophryotrocha puerilis is the first species hitherto described which possesses four instead of two nuchal organs. These sensory structures are located as ciliary pits at the posterior margin of the prostomium. Histologically, the nuchal organs are composed of supporting cells with long motile cilia and bipolar sensory cells, the perikarya of which form four distinct nuchal ganglia adjoining the brain. These structural components are concentrically arranged around the central sensory area. This area is covered by a modified cuticle, whereas the cuticle above the peripheral region of the sense organ exhibits the appearance typical for polychaetes. Two types of vesicular material are produced in the basal supporting cells, a dense-cored one within the central supporting cells only and a clear irregular-shaped one in all of these cells. The first type is considered to be responsible for the formation of the modified cuticle. The significance of these most probably long-distance chemoreceptory organs and their possible role in reproductive behaviour is discussed.
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    URL: http://dx.doi.org/10.1007/BF00312164
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  • 96
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    Morphology and histology of the disc autotomy plane in Ophiophragmus filograneus (Echinodermata, Ophiurida) (1989)
    Springer
    Zoomorphology 108 (1989), S. 323-332 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Normal and autotomized specimens of Ophiophragmus filograneus were studied by gross dissection, light microscopy, transmission electron microscopy, and scanning electron microscopy to determine how autotomy occurs at the major region of disc attachment. Each of the 10 genital bars is attached to an arm by a broad ligament consisting of a thick outer layer of collagenous connective tissue and an inner layer of neurosecretory cells innervated by a lateral ectoneural branch of the radial nerve. Neurosecretory cell processes extend into the collagenous layer. During autotomy the collagenous fibers separate, weakening the ligament near its insertion along the genital bar. Collagen fiber separation is probably caused by neurosecretions. There is no evidence for ossicle dissolution. The results indicate that the histological organization of the genital bar ligaments is identical to that of mutable collagenous tissues in other echinoderms and that the autotomy process is similar to that described for other echinoderms.
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    URL: http://dx.doi.org/10.1007/BF00312273
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  • 97
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    The nervous system of the actinotroch larva of Phoronis muelleri (Phoronida) (1989)
    Springer
    Zoomorphology 108 (1989), S. 333-351 
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    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nervous system of the actinotroch larva of Phoronis muelleri has been investigated with the transmission electron microscope (TEM). Attempts have been made to localize all of the major nerves and to reveal the cytoarchitecture of the apical ganglion. The nervous system is intraepithelial in position and consists of an apical ganglion, located on the epistome, with at least four different cell types, including monopolar sensory cells and mono- or multipolar neuron-like cells. From the anterior part of the apical ganglion three median nerves extend to the edge of the epistome; two of these nerves connect to nerves which follow the edge of the epistome all the way to the junction of the epistome and the mesosome. From the posterior part of the ganglion extend two lateral nerves which continue along the tentacular ring. Each tentacle has three nerves located on the frontal side which connect to the nerve ring along the tentacles. Along the posterior ciliary band is a minor nerve ring. In addition, a nerve net is found on the epistome, mesosome, and metasome, but no longitudinal nerves were observed between the posterior ciliary band and the apical ganglion. All nerve cells were found in the apical ganglion and none was observed along the nerves. Sensory cells (probably mechanoreceptors) are located in two rows on each tentacle; sensory organs such as eyes and statocysts were not observed.
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    URL: http://dx.doi.org/10.1007/BF00312274
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  • 98
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    Feinstruktur des ventralen mandibulären Muskelrezeptors bei Liposcelis bostrichophilus (Insecta, Psocoptera) (1989)
    Springer
    Zoomorphology 108 (1989), S. 353-358 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der ventrale Mandibel-Muskelrezeptor wird im Kopf von Liposcelis bostrichophilus (Psocoptera) nachgewiesen. Er zieht, median der Mandibel-Gelenkachse gelegen, vom vorderen Tentorium-Arm zur hinteren Mandibel-Basis und wird also während der Abduktion der Mandibel gedehnt. Der Rezeptor besteht aus einer motorisch und sensorisch innervierten Muskelfaser und 10 bipolaren, multiterminalen Sinneszellen. Einige der Sinneszellen senden ihre Dendriten ins Innere des Rezeptor-Muskels, wo sie sich verzweigen und jeweils an den Z-Scheiben enden. Die übrigen Sinneszellen bilden mit ihren Dendriten ein Bündel, das der Oberfläche des Rezeptor-Muskels anliegt. Nur die ins Innere ziehenden Dendriten weisen in ihren Endigungen Tubularkörper-ähnliche Strukturen auf. Sowohl die Sinneszellen als auch der Rezeptor-Muskel werden von Hüllzell-Wicklungen eng umhüllt.
    Notes: Summary The ventral mandibular muscle receptor in the head of Liposcelis bostrichophilus (Psocoptera) is described. It is located median to the mandibular hinge axis, extending from the front tentorium to the dorsal mandibular basis, and is stretched according to the movements of the mandible. The receptor consists of a sensorily and a motor-stimulated muscle fibre and ten bipolar multiterminal neurons. Some of the neurons send their dendrites into the inner part of the receptor muscle, where they branch and terminate at the level of the Z discs. The other neurons build a dendritic bunch, which runs parallel to the muscle fibre surface. Only the dendrites located close to the Z discs show tubular-body-like structures in their terminal ends. The multiterminal neurons and the receptor muscle are covered with glial cells.
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    URL: http://dx.doi.org/10.1007/BF00312275
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    The morphology of the phallosome and accessory gland material transfer during copulation in the blowfly, Lucilia cuprina (Insecta, Diptera) (1989)
    Springer
    Zoomorphology 108 (1989), S. 359-366 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mechanism of insemination in Lucilia cuprina is described. There are four duct openings on the phallosome. The terminal pore is continuous with the internal reproductive organs. The sub-terminal pore and paired, lateral pores are the openings of ducts formed by cuticular invaginations. The male accessory gland material appears to be re-routed from the terminal pore into the ducts of the lateral barbs once sperm transfer is complete. A novel means of deposition of the male accessory material is described, in which paired barbs on the phallosome tear the cuticle of thick-walled pads in the bursa copulatrix. After mating, accessory material is found within intra-cuticular spaces in the bursa copulatrix, which appear to become sealed at the points of penetration by plugs or scars.
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    URL: http://dx.doi.org/10.1007/BF00312276
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    Fine structure of the accessory glands of the female genital tract of the ichneumonid Pimpla turionellae (Insecta, Hymenoptera) (1989)
    Springer
    Zoomorphology 108 (1989), S. 367-377 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The female accessory glands include the tubular poison gland, the paired, lemon-shaped uterus glands, and Dufour's gland, an unbranched tubular organ. They consist essentially of a single layer of epithelium cells surrounded by a basement membrane. The lumen is lined by cuticle. The proteinaceous secretion of the poison gland is released into intracellular ducts provided with microvilli, each connected to a channel lined with cuticle which leads to the central lumen of the gland. The channel is formed by special canal cells. Nerve endings are interspersed among the gland cells. The uterus gland consists of four cell types derived from a single type of precursor cell found in newly hatched wasps. Type I cells are covered by type II cells and are thus without contact to the luminal surface of the gland. They contain stacks or whorls of mitochondria and smooth cisternae in an alternating arrangement. Vesicles with a secretory product are found in cells of types II and III. Deep anastomosing infoldings of the plasmalemma, stabilized by microtubules and dense material at the branchings, are characteristic for type II cells. Most secretory vesicles are found in type III cells, the prevalent cell type which is thought to be the source of the lipoprotein secretion. Coated vesicles are present at deep infoldings of the plasmalemma. The greatly enlarged apical surface area of type IV cells and the presence of mitochondria in slender outgrowths is suggestive of an osmoregulatory function. In Dufour's gland, two cell types appear in succession, the first with a very dense cytoplasm, the second with dense inclusions and many seemingly empty vesicles of smooth endoplasmic reticulum. The secretion products, lecithin and a cholesterol ester, are thought to be formed by the second cell type. The dense inclusion might be lecithin, which reacts with osmium tetroxide. The cholesterol ester could have been washed out of the “empty” vesicles by the embedding procedure.
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    URL: http://dx.doi.org/10.1007/BF00312277
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