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  • 1
    Electronic Resource
    Electronic Resource
    Detection and features of wetwood in Quercus mongolica var. grosseserrata (1995)
    Springer
    Trees 9 (1995), S. 261-268 
    Details
    ISSN: 1432-2285
    Keywords: Quercus mongolica var. grosseserrata ; Wetwood ; Moisture content ; Cryo-SEM ; Soft x-ray photography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To elucidate the location of water in wetwood, variations in moisture content within a tree of Quercus mongolica var. grosseserrata were observed macroscopically by determination of moisture content and by soft x-ray photography. Then the typical wetwood, which had been precisely located by such macroscopic analysis, was examined further by cryo-scanning electron microscopy. The moisture content varied considerably within the tree trunk, and typical wetwood was detected in limited regions of the heartwood. The distribution of the wetwood did not always correspond to the discoloration of the wood. In the wetwood, almost all the lumina of vessels and fibers were filled with water, while the lumina of ray and axial parenchyma cells were often cavitated. Intercellular spaces produced by deformation of cell walls and radial shakes were filled with water. In addition, tyloses were collapsed and torn in the wetwood, and they did not block the vessel lumina. These results suggest the possibility that vessels and fibers might serve as effective pathways for the accumulation of water in the wetwood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202016
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Timing of the occurrence of frost cracks in winter (1996)
    Springer
    Trees 11 (1996), S. 47-53 
    Details
    ISSN: 0931-1890
    Keywords: Key words Frost crack ; Low temperature ; Freezing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  In order to determine the timing of the occurrence of frost cracks, as well as to evaluate the climatic conditions associated with such occurrences, study plots were established in late autumn and early winter. Serial observations were made to identify both the occurrence of new frost cracks and the re-opening of old frost cracks in trees in the study plots until mid-winter or early spring. Field observations were conducted for three winter seasons in different study plots. Most old frost cracks were found to re-open in early winter. However, such re-opening did not occur simultaneously within a very limited period of time, for example, within a single day or night, when air temperature fell suddenly or considerably. Re-opening seemed to occur steadily over the course of several days of continuous subzero temperatures. It has been suggested that freezing of the trunk contributes considerably to the re-opening of old frost cracks. Four frost cracks from 1002 trees were newly formed during the course of this study. The new frost cracks developed both in early winter and mid-winter. It has been suggested that new frost cracks can occur during the same period when most old frost cracks re-open and the air temperature does not fall far below 0°C. However, it remains unclear whether or not there is a tendency for new frost cracks to occur during a particular period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004680050057
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Abrupt growth changes in Norway spruce and Yezo spruce near an industrial district in Hokkaido, Japan (1997)
    Springer
    Trees 11 (1997), S. 183-189 
    Details
    ISSN: 0931-1890
    Keywords: Key words Dendrochronology ; Abrupt growth changes ; Pointer years ; Air pollution ; Drought
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Increments in the radii of Norway spruce (Picea abies Karst.) and Yezo spruce (Picea jezoensis Carr.) trees that revealed symptoms of a decline in growth were analyzed by dendrochronological methods in an attempt to correlate past reductions in growth with their main causes. The trees were growing at different sites near the industrial district of Tomakomai, Hokkaido. A skeleton plot method was used to construct a series of pointer years that revealed the number of trees with a clear reduction in growth or recovery from such a reduction. An analysis of “abrupt growth changes” demonstrated that at least two periods of growth reduction were common to a large number of Norway spruce trees. The reduction events were related to the records of industrial activity near the forest and meteorological data. The growth reduction in the 1970s coincided with the start of operation of certain local factories, and its extent was related to the distance from the industrial region. By contrast, a reduction in growth in 1984 was detected at all the Norway spruce sites and the extent was approximately the same at all sites. This phenomenon was related to extreme drought conditions. Growth of Yezo spruce trees was less sensitive to industrial activity and to drought than that of Norway spruce. Thus, differences in response to air pollution and drought were observed between the two species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004680050075
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Changes in the arrangement of cellulose microfibrils associated with the cessation of cell expansion in tracheids (1997)
    Springer
    Trees 11 (1997), S. 328-332 
    Details
    ISSN: 0931-1890
    Keywords: Key words Cellulose microfibril ; Tracheid ; Cell expansion ; Abies sachalinensis ; Secondary wall formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The relationship between the cessation of cell expansion and formation of the secondary wall was investigated in the early-wood tracheids of Abies sachalinensis Masters by image analysis and field emission scanning electron microscopy. The area of the lumen and the length of the perimeter of the lumen of differentiating tracheids increased from the cambium towards the xylem. These increases had just ceased in the case of tracheids closest to the cambium in which birefringence was first detected by observations with a polarizing light microscope. Cellulose microfibrils (MFs) deposited on the innermost surfaces of radial walls were not well ordered during the expansion of cells, but well ordered MFs were deposited at the subsequent stage of cell wall formation. The first well ordered MFs were oriented in an S-helix. The well ordered MFs had already been deposited at the tracheids where birefringence was first detected under the polarizing light microscope. These results indicate that the deposition of the well ordered MFs, namely, the formation of the secondary wall, begins before the cessation of cell expansion of tracheids. Therefore, it seems that the expansion of tracheids is restricted by the deposition of the secondary wall because the cell walls become rigid simultaneously with the development of the secondary wall and, therefore, the yield point of cell walls exceeds the turgor pressure of the cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004680050092
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Changes in tree ring width and density ofPinus thunbergii growing in the vicinity of industrial complex in Korea (1997)
    Springer
    Journal of forest research 2 (1997), S. 109-113 
    Details
    ISSN: 1610-7403
    Keywords: air pollution ; Pinus thunbergii ; ring density ; tree ring width
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract There has been a decline in tree growth since the operation of factories atPinus thunbergii forests around a petrochemical industrial complex in Korea. This study was carried out to investigate the effects of air pollution on tree ring width and ring density ofPinus thunbergii. Soft X-ray densitometrical method was used. Decline of ring width was the highest during 3 years immediately after the operation of factories. The percentage of decrease was almost bigger immediately after operation as compared with before. Maximum density (MAXD), and the difference (DD) between maximum density and minimum density (MIND) generally decreased since operation of factories, while minimum density increased in the beginning of operation of factories. There was a significant correlation between ring width and high temperature, and precipitation in the beginning of growing season, respectively. There was also a negative correlation between annual mean concentration of SO2 and ring width at 5% level (r=−0.627*). It is suggested that the decline of ring width after operation of factories was due to compound factors of air pollution and climate. The effect of other factors should be still more studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348478
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    Paper (German National Licenses)
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