The nature of reaction wood. VII. Lignification in reaction wood

1963 ◽  
Vol 11 (2) ◽  
pp. 107 ◽  
Author(s):  
G Scurfield ◽  
. Wardrop.A.B
Keyword(s):  
Direct Methods ◽  
Growing Season ◽  
Liquidambar Styraciflua ◽  
Wall Structure ◽  
Reaction Wood ◽  
Grevillea Robusta ◽  
Gelatinous Layer ◽  
Wood Fibres ◽  
Staining Techniques ◽  
Maximum Expression

Lignification of reaction wood, caused to form in the stems of seedlings of Trisrania conferta K.Br., Grevillea robusta A.Cunn., Eucalyptus botryoides Sm., E. Melliodora A.Cunn. ex Schau., Hakea laurina R.Br., and Liquidambar styraciflua L., has been investigated with the use of ultraviolet microscopy and staining techniques. The polarizing microscope was used in a supplementary study of cell wall structure. The "gelatinous" layer of reaction wood fibres undergoes lignification, the extent depending on whether the fibres are located in the middle or on the edges of areas of reaction wood. There is evidence for the diffusion outwards into the "gelatinous" layer of breakdown products of cell protoplasts. As the growing season advances, there is a progressive reduction in the number of cambium cells dividing to form reaction wood fibres. This process reaches its maximum expression in the deciduous species Liquidambar styraciflua, where there is a complete change-over to the production of normal cells at the end of the growing season. The anatomical features of three areas of reaction wood caused to form in stems of Tristania conferta and Eucalyptus melliodora by orientating horizontally growing plants twice through 180° are described. They further emphasize the importance of the location of individual reaction wood cells in the stem in determining the structure of their walls and the pattern of wall lignification. The results of staining sections for the enzyme peroxidase with benzidinehydrogen peroxide are described. They point to the need for closer investigation by direct methods of enzyme isolation and estimation.

The nature of reaction wood. IV. Variations in cell wall organization of tension wood fibres

1955 ◽  
Vol 3 (2) ◽  
pp. 177 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Tension Wood ◽  
Secondary Wall ◽  
Degree Of Crystallinity ◽  
Tropical Species ◽  
Normal Wood ◽  
Reaction Wood ◽  
Gelatinous Layer ◽  
Wood Fibres ◽  
Cell Wall Organization

The cell wall organization, the cell wall texture, and the degree of lignification of tension wood fibres have been investigated in a wide variety of temperate and tropical species. Following earlier work describing the cell wall structure of tension wood fibres, two additional types of cell wall organization have been observed. In one of these, the inner thick "gelatinous" layer which is typical of tension wood fibres exists in addition to the normal three-layered structure of the secondary wall; in the other only the outer layer of the secondary wall and the thick gelatinous layer are present. In all the tension wood examined the micellar orientation in the inner gelatinous layer has been shown to be nearly axial and the cellulose of this layer found to be in a highly crystalline state. A general argument is presented as to the meaning of differences in the degree, of crystallinity of cellulose. The high degree of crystallinity of cellulose in tension wood as compared with normal wood is attributed to a greater degree of lateral order in the crystalline regions of tension wood, whereas the paracrystalline phase is similar in both cases. The degree of lignification in tension wood fibres has been shown to be extremely variable. However, where the degree of tension wood development is marked as revealed by the thickness of the gelatinous layer the lack of lignification is also most marked. Severity of tension wood formation and lack of lignification have also been correlated with the incidence of irreversible collapse in tension wood. Such collapse can occur even when no whole fibres are present, e.g. in thin cross sections. Microscopic examination of collapsed samples of tension wood has led to the conclusion that the appearance of collapse in specimens containing tendon wood can often be attributed in part to excessive shrinkage associated with the development of fissures between cells, although true collapse does also occur. Possible explanations of the irreversible shrinkage and collapse of tension wood fibres are advanced.

The nature of reaction wood. IX. Anomalous cases of reaction anatomy

1964 ◽  
Vol 12 (2) ◽  
pp. 173 ◽  
Author(s):  
G Scurfield
Keyword(s):  
Cross Sectional Area ◽  
Axial Position ◽  
Vertical Position ◽  
Reaction Wood ◽  
Vascular Bundles ◽  
Sectional Area ◽  
Cross Sectional ◽  
Gelatinous Layer ◽  
Stage Of Development ◽  
Wood Fibres

The reaction anatomy of 14 species of Acacia, Lagunaria pattersoni, and the woody monocotyledons Dracaena fragrans and D. marginata was examined with light, polarizing, and ultraviolet microscopes. Notable features of the reaction wood fibres of Acacia spp. were: the absence of birefringence in the sublayers of the "gelatinous" layer at all stages of their deposition; the absence of radial striations in the gelatinous layer; the frequency of occurrence of fibres lacking protoplasts and with convoluted gelatinous layers at some intermediate stage of development; the relatively wide separation of stages of gelatinous layer formation in passing from cambium towards pith; and the poor adherence of the gelatinous layer to previously formed cell wall layers. It was concluded that the forces bringing about gelatinous layer deposition were either weaker or slower to develop, or both, than in species such as Tristania conferta. Possible reasons for this are discussed. Deposition of starch grains in reaction wood fibres occurred in all Acacia spp, towards the end of the growing season. A gelatinous layer did not occur in reaction wood fibres of Lagunaria pattersoni. These differed from normal fibres only in the thinness of their walls and their relatively large cross-sectional area. Examination of the wall structure of phloem fibres indicated that changes in microfibril orientation towards a more axial position which occurred in layer S2 of primary phloem fibres were accelerated on the upper sides of bent stems. The significance of this feature, and of possible tensions developed in the outer cortex and epidermis on the upper sides of bent stems because of accelerated phloem and xylem development, are discussed in relation to mechanisms whereby such stems may recover to a vertical position. The number of vascular bundles and the wall thickness and extent of lignification of the fibres of the bundle sheaths, were increased on the upper sides of horizontally grown stems of Dracaena spp. The radial width of the cortex and the cross-sectional area of cortical cells were less than on the lower sides of the stems.

Tolerance of Planed Hardwoods to Spring Flooding

1977 ◽  
Vol 1 (3) ◽  
pp. 23-25 ◽  
Author(s):  
James B. Baker
Keyword(s):  
Populus Deltoides ◽  
Growing Season ◽  
Liquidambar Styraciflua ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Nyssa Aquatica ◽  
Eastern Cottonwood ◽  
Platanus Occidentalis ◽  
Water Tupelo ◽  
Root Collar

Abstract Cuttings of eastern cottonwood (Populus deltoides) and seedlings of sweetgum (Liquidambar styraciflua), water tupelo (Nyssa aquatica), American sycamore (Platanus occidentalis), and green ash (Fraxinus pennsylvanica) were planted on a slackwater clay (Vertic Haplaquept) in western Mississippi in two consecutive years and inundated soon after foliation. During each of the two years, survival following flooding was consistently high for water tupelo, green ash, and sycamore, low for cottonwood, and intermediate for sweetgum. With the exception of green ash, however, all species lost their leaves and died back to the root collar during flooding. Thus trees, other than ash, that were living at the end of the growing season had originated from root collar sprouts.

ANATOMY AND CHEMICAL COMPOSITION OF LIRIODENDRON TULIPIFERA STEMS INCLINED AT DIFFERENT ANGLES

IAWA Journal ◽  
2014 ◽  
Vol 35 (4) ◽  
pp. 463-475 ◽  
Author(s):  
Tokiko Hiraiwa ◽  
Haruna Aiso ◽  
Futoshi Ishiguri ◽  
Yuya Takashima ◽  
Kazuya Iizuka ◽  
...  
Keyword(s):  
Lignin Content ◽  
Fibre Length ◽  
Liriodendron Tulipifera ◽  
Original Position ◽  
Chemical Characteristics ◽  
Normal Wood ◽  
Reaction Wood ◽  
Glucose Content ◽  
Wood Fibres ◽  
S2 Layer

The anatomical and chemical characteristics of reaction wood (RW) were investigated in Liriodendron tulipifera Linn. Stems of seedlings were artificially inclined at angles of 30 (RW-30), 50 (RW-50) and 70° (RW-70) from the vertical, and compared with normal wood (NW) from a vertical seedling stem. The smallest values for the wood fibre length and vessel number were observed in RW-50. The pit aperture angle was less than 10° in RW-30 and RW-50, in which reduced lignin content was observed in the S2 layer of the wood fibres. An increase in the glucose content and a decrease in the lignin and xylose content was observed in RW-50. The stem inclination angle affected the degree of RW development with regard to anatomical and chemical characteristics: the severest RW was observed in RW-50, followed by RW-30. RW-70 was similar in anatomical and chemical characteristics to NW, apparently because the inclination was too strong to enable recovery of its original position. In this case a vertical sprouting stem was formed to replace the inclined stem.

Response of Nine-Year-Old Plantation Sweetgum to Nitrogen Fertilization in Mississippi

1992 ◽  
Vol 16 (3) ◽  
pp. 146-150
Author(s):  
L. E. Nelson ◽  
G. L. Switzer
Keyword(s):  
Nitrogen Fertilization ◽  
Basal Area ◽  
Woody Biomass ◽  
Growing Season ◽  
Maximum Growth ◽  
Liquidambar Styraciflua ◽  
Stem Volume ◽  
Breast Height ◽  
Seed Sources ◽  
N Rates

Abstract Nine-year-old planted sweetgum (Liquidambar styraciflua L.) consisting of four half-sib seed sources were refertilized with nitrogen in 1981 at the beginning of the tenth field-growing season. Increases in periodic annual height, diameter at breast height, basal area, stem volume (ob),and woody biomass increments of all four half-sib seed sources from applied nitrogen were observed during the 9 years following application. Periodic annual stem volume (ob) increments averaged over all half-sib seed sources were 120, 152, 192, and 266 ft³/ac/yr for the 0, 89, 178, and356 lb/ac N rates, respectively. The half-sib seed sources from alluvial sites were superior to those from upland sites in terms of productivity and response to N. The response of all half-sibs to N was immediate, occurring during the year of application; however, the increased growth ratesdue to N persisted for only 3 years. This suggests that on responsive sites, applications of N may be necessary every fourth year to maintain maximum growth rates. South. J. Appl. For. 16(3):146-150.

scholarly journals The Nature of Reaction Wood

1948 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
AB Wardrop ◽  
HE Dads Well
Keyword(s):  
Tensile Strength ◽  
Tension Wood ◽  
Reaction Wood ◽  
Fibre Structure ◽  
Longitudinal Shrinkage ◽  
High Tensile Strength ◽  
Wood Fibres

The structure of tension wood fibres is ofconsiderahle academic and practicalinterest, both in relation to considerations of the stimuli which produce them,and to studies of the influence of fibre structure on the properties of the wood asa whole. As is well known, the chief abnormal properties of tension wood lie inits unusually high longitudinal shrinkage, its high tensile strength, and its lowcompressive strength .

Analysing Daily Rainfall Measurements to Give Agronomically Useful Results. I. Direct Methods

1982 ◽  
Vol 18 (3) ◽  
pp. 223-236 ◽  
Author(s):  
R. D. Stern ◽  
M. D. Dennett ◽  
I. C. Dale
Keyword(s):  
Random Sample ◽  
Distinctive Feature ◽  
Relative Frequency ◽  
Daily Rainfall ◽  
Direct Methods ◽  
Growing Season ◽  
Simple Random Sample ◽  
Frequency Of Occurrence ◽  
Dry Spells

SummarySimple methods are described for the analysis of daily rainfall measurements. The distinctive feature is that each year provides one number for any event or characteristic of interest. The resulting observations are then analysed, assuming that they are a simple random sample from a single distribution. An estimate of the probability of an event can be made directly from its relative frequency of occurrence, or alternatively a distribution (such as the normal) can be fitted. The methods are applied to agronomic questions on dry spells, the start, end and length of the growing season, and the distribution of amounts of rainfall through the year. Examples are given from Nigeria and India.

CHARACTERISTICS OF TROCHODENDRON ARALIOIDES TENSION WOOD FORMED AT DIFFERENT INCLINATION ANGLES

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Tokiko Hiraiwa ◽  
Tatsuya Toyoizumi ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Tension Wood ◽  
Growth Promotion ◽  
Growth Stress ◽  
Aperture Angle ◽  
Wall Structure ◽  
Cellulose Content ◽  
Klason Lignin ◽  
Glucose Content ◽  
Gelatinous Layer ◽  
Inclination Angles

To assess the characteristics of tension wood (TW) in Trochodendron aralioides Sieb. et Zucc., seedling stems were artificially inclined at angles of 30° (TW- 30), 50° (TW-50), and 70° (TW-70) from the vertical. At all angles, the growth promotion was pronounced on the upper side of the inclined stems, where excessive tensile growth stress was observed. A gelatinous layer (G-layer) formed in the tracheids of TW. The cell wall structure of the tracheids in TW was S1 + G. The G-layer had a small pit aperture angle <10°. TW-50 showed larger tensile growth stress, a thicker G-layer area, and a smaller pit aperture angle of the Glayer than TW-30 and TW-70. Lower levels of Klason lignin and hemicellulose and higher levels of α-cellulose content were observed in TW-50. In addition, an increase in glucose content and a decrease in xylose content in holocellulose were observed in TW-50. Therefore, it can be concluded that the degree of TW varied with different inclination angles.

The nature of reaction wood. VI. The reaction anatomy of seedlings of woody perennials.

1962 ◽  
Vol 10 (2) ◽  
pp. 93 ◽  
Author(s):  
G Scurfield ◽  
AB Wardrop
Keyword(s):  
Fibre Length ◽  
Structural Features ◽  
Age Difference ◽  
Reaction Wood ◽  
Lower Side ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Gelatinous Layer ◽  
Ray Cells ◽  
Electron Microscopes

The reaction anatomy of the stems of seedlings of A 1 species of hroad-leaved trees was examined. The reaction was induced by bending the stems at right angles or growing the plants horizontally. As a result of greater cambial activity on the upper side such stems developed a structural asymmetry characterized by enhanced xylem and phloem development. The structural features of the lower side were similar to those of stems grown vertically. The xylem on the upper side contained fewer vessels, more fibres, and fewer medullary rays than that on the lower side of the same stem. "Gelatinous" layers developed within the reaction fibres as well as in fibres of the phloem. Vessels, medullary ray cells, and parenchyma cells were often compressed and sometimes obliterated. Reaction fibres showed reduced wall pitting and tended to retain their contents until they lay relatively deep within the stem. There were no differences in fibre length between upper and lower sides of the stem, but comparisons were probably confounded with an age difference. Cortical cells and, in species where they occurred, canals were compressed on that side of the stem. Such cortical cells were not only smaller in cross section than those on the lower side, but were also shorter in length. This was also a feature of medullary ray cells. There was a greater accumulation of tannins in phloem and cortex on the upper side of the stem. The structure of reaction fibres was examined in ultraviolet, polarizing, and electron microscopes. In the first of these, the "gelatinous" layer was seen to consist of a series of concentric bands convoluted towards the cell lumen, the bands containing radial striations. The polarizing microscope showed that the innermost part of the wall possessed some birefringence. Both convolutions and birefringence tended to disappear as the cells matured; staining with Congo red became less intense. The heterogeneity of the "gelatinous" layer was confirmed by electron microscopic examination. The results are discussed in connection with the gravimorphic responses of displaced stems, the altered patterns of lignification, and the development of growth stresses in such stems.

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