GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: II. SPECIFIC INCREMENTS AND THEIR RELATION TO THE QUANTITY AND ACTIVITY OF GROWTH IN PINUS RESINOSA AIT.

1957 ◽  
Vol 35 (4) ◽  
pp. 527-572 ◽  
Author(s):  
G. H. Duff ◽  
Norah J. Nolan

Two measures are needed to describe numerically the activity of the internodal cambium in terms of annual increment. These are "specific wood volume increment", a measure of additive growth and "specific increment of cambial area", a measure of multiplicative growth. The mean area of the internodal cambium is the basis of reference for both since it is the measure of that which is active in growth. The former measure of specific growth is numerically equal to ring width and the manner of its factorial control has already been considered. Data for the latter are new.The geometry of the apical meristem and its products is too complex for the ready computation of specific terminal growth, but it can be shown empirically that internode length is a valid measure of apical activity. Analysis of internodal wood volume growth into its three linear components leads to the conclusion that the determinants in control of wood growth act mainly through their effect upon apical activity and upon specific increment of cambial area.


1953 ◽  
Vol 31 (4) ◽  
pp. 471-513 ◽  
Author(s):  
G. H. Duff ◽  
Norah J. Nolan

The anomalous complexity of the annual rings of young trees which generally disqualifies them from use in growth studies is, in P. resinosa, found to arise from a remarkably thorough organization of ring width and therefore of cambial activity in the tree under the influence of intrinsic determinants. The pattern is manifest when the widths of the internodal wood rings of a single year are followed in sequence from internode to internode down the tree from the apex. A similarly patterned view of the rings is obtained when the ring widths are traced in the ring sequence, conventional for growth studies, that passes from ring to ring in a given internode. The controlling intrinsic factors are held to be nutritional gradients in the axis inferred from the distribution of foliage and light along the axis of trees growing in the forest and in the open.In both types of sequence the pattern obscures the variations induced by random extrinsic factors and severely limits the value of these sequences for examining the effect of such factors. This disability can be avoided by the use of a third sequence of ring widths in which each term is the width of a ring which was laid down in an internode different but of the same age at the time of ring formation as the others in the sequence. Such sequences have never been used in growth studies. Yet they are found to be unpatterned and the effect of the fluctuating extrinsic factors can be examined effectively in them and in them alone.The complex relation between the responses of the cambium thus determined and those of the apical growing point to the random extrinsic factors is found to derive from the discontinuity of terminal growth introduced by the winter pause between bud formation and axial extension. These two stages of terminal growth are influenced by the extrinsic factors of the two different years. The effect on the cambium is simpler than this but is determinably related to that on the apical growing point.The results afford the ground for a first advance toward the removal of the disqualification of the use of young trees in studies of growth and of its factorial control.



IAWA Journal ◽  
1991 ◽  
Vol 12 (3) ◽  
pp. 263-274 ◽  
Author(s):  
A. E. Akachuku

Leaning red pine (Pinus resinosa) trees at Harvard Forest in Petersham, Massachusetts, U.S.A., were sampled for wood growth studies 50 years after they were displaced by a hurricane. Before the hurricane incursion, ring width varied among trees and from year to year but not among radiL After the hurricane, between-tree variation in ring width was again significant but it was not appreciably due to angle of displacement (AOD) of the bole. Wood growth distribution along the bole in the leaning trees was complex. Between- radius variation in ring width was significant in the leaning boles; ring width was largest on the lower side. On the average ring width decreased as tree age increased but the variation was much less on the upper than on the lower side. Ring area tended to decrease with increase in age but the relationship was strongest in the least displaced bole and vice versa. Asymmetrie growth ratio increased with AOD of a bole and varied with year of wood formation but was not related to cambium age. Graphs of height above the ground on percentage pith eccentricity exhibited a sinuous shape like that of the trees. Cumulative growth and mean annual increment of height and volume increased with tree age. Current annual increment of height and volurne decreased for 9 and 5 years after the hurricane and after the 64th and 69th year of the tree, respectively. Form factor increased after pruning but decreased later with age. Precipitation was not closely related to ring width in the leaning boles.



1962 ◽  
Vol 40 (1) ◽  
pp. 95-111 ◽  
Author(s):  
D. F. Forward ◽  
N. J. Nolan

Analysis of the growth of four trees from contrasting situations is extended to include the specific increment of cambial area, which is a measure of multiplicative growth of the cambium. This is found to correspond to radial growth, as measured by ring width, in the upper portion of the main axis and in the branches. Like ring width it exhibits the effects of intratree suppression and of a change from a condition of suppression to one of open growth. In the branches it is dependent on the position of the branch at the time of ring formation, and in those branches that are near the top of the crown, corresponding internodal rings show a higher specific increment of cambial area than those that are suppressed by overlying whorls. It is concluded that the factors controlling multiplicative growth of the cambium are essentially the same as those controlling radial growth.



1961 ◽  
Vol 39 (2) ◽  
pp. 411-436 ◽  
Author(s):  
Dorothy F. Forward ◽  
Norah J. Nolan

The analysis of growth in trunk and branches of four red pine trees of different situations is extended to include internode length, circumference, annual wood volume increment, and cambial area. The effects of position of a branch on the tree and of suppression and release are examined in reference to these growth indexes.Increase in circumference responds in much the same way as radial growth, and branch position is important. The greatest annual increase in girth of any branch internode occurs when it is near the periphery and near the top of the tree.Terminal growth of branches is less affected than radial or tangential growth by branch position if the tree is in the open but is suppressed by surrounding trees. Upon release of a tree only those axes whose local environment was actually improved showed an increase in apical growth.The interpretation of annual wood volume increment is complicated by the fact that it is determined not only by internal and external conditions during the current growing season, but also by past growth, both apical and cambial. It is subject to the effects of suppression and of branch position, chiefly through the influence of these factors on the cambial growth component.



1996 ◽  
Vol 26 (4) ◽  
pp. 624-626 ◽  
Author(s):  
Richard A. Fleming

Improved derivations are provided for the specific increments of internodal growth. These derivations strengthen the theoretical basis of the concept of specific growth. Despite being based on a more rigorous approach, however, these derivations produce a specific wood volume increment equation that is identical with the standard version. In contrast, a new equation emerges for the specific (annual) increment of cambial area: SAI = ln(rn/rn−1), where ln denotes the natural logarithm and rn and rn−1 are the cambial radii corresponding to the annual rings produced in years n and n − 1, respectively. The standard approximation underestimates the specific area increment, especially on young, fast-growing internodes, but even then the error involved may be small. Any standard approximation to SAI can be corrected by multiplication with the provided correction factor (which requires values for rn and rn−1 only).



Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 528-536 ◽  
Author(s):  
Denis Barabé ◽  
Laura Bourque ◽  
Xiaofeng Yin ◽  
Christian Lacroix

Previous studies on palm phyllotaxis deal mainly with the mature trunk. The goals of this study are (i) to determine the relationship between the number of parastichies, the divergence angle, and the plastochrone ratio at the level of the shoot apical meristem; (ii) to examine whether there are fluctuations in the divergence angle; (iii) to interpret the significance of phyllotactic parameters with respect to the mode of growth of the apex. The tubular base of the leaf primordium is more or less asymmetrical, and completely surrounds the shoot apical meristem. The phyllotactic system corresponds to a (2, 3) conspicuous parastichy pair. The mean divergence angle per apex varies between 126.9° ± 9.3° (mean ± SD) and 135. 8° ± 8.0°. Divergence angles for all apices fluctuate within a range of 115.89° to 157.33°. The mean plastochrone ratios between apices varies from 1.35 ± 0.18 to 1.58 ± 0.12. The plastochrone ratio at each plastochrone for all apices ranges from 1.09 to 2.00. There is no correlation between the angle of divergence and the plastochrone ratio. There is a fluctuation in the value of the divergence angle that falls within the range predicted by the fundamental theorem of phyllotaxis. The high value of the ratio of the diameter of leaf primordia over the diameter of the apex, and the long plastochrone might explain the lack of correlation between certain phyllotactic parameters.



2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Rui Zhang ◽  
Yinjing Guo ◽  
Xiangrong Wang ◽  
Xueqing Zhang

This paper extends the stochastic stability criteria of two measures to the mean stability and proves the stability criteria for a kind of stochastic Itô’s systems. Moreover, by applying optimal control approaches, the mean stability criteria in terms of two measures are also obtained for the stochastic systems with coefficient’s uncertainty.



1969 ◽  
Vol 1 (3) ◽  
pp. 247-271 ◽  
Author(s):  
James Maxwell

In 1932 all 11-year-old children in Scottish schools were given a group intelligence test, and a sample of 1000 was individually tested. The future careers of this sample were followed till 1939. In 1968, 709 of the original sample could be traced, and data about education, employment, and family were obtained. In 1947, a parallel survey was conducted in Scotland, and a sample of 1208 children was individually tested, and followed up for 16 years. The same data about education, employment and family are available for the 1947 Sample.A comparison between length of school education indicates a greater proportion completing a full secondary education in the 1947 than in the 1932 Sample. Proportionally, more of the 1947 Sample graduated from university. In marriage, it is possible to cut across the 1932 Sample at the age of 27 years, to make direct comparison with the 1947 Sample at the same age. The greatest incidence of marriage is in the middle range of IQ, but later records for the 1932 Sample show a relative uniformity of marriage over the IQ range. The pattern for occupational class is similar. There is a slight tendency to later marriage in the 1932 Sample. Two measures of differential fertility for IQ are used. For both samples, there is a negative relationship between the mean IQs of the sample members and the number of their sibs, more marked for the 1947 Sample. The number of children born to members of the two samples before the age of 27 years shows a similar relationship, but in the following 20 years the pattern for the 1932 Sample changes to one with a peak of mean IQ at two children. It is suggested that linear differential fertility for IQ may be a function of the age of the parent.



Neurosurgery ◽  
2016 ◽  
Vol 79 (5) ◽  
pp. 722-735 ◽  
Author(s):  
Guillaume Coll ◽  
Jean-Jacques Lemaire ◽  
Federico Di Rocco ◽  
Isabelle Barthélémy ◽  
Jean-Marc Garcier ◽  
...  

Abstract BACKGROUND: To date, no study has compared the evolution of the foramen magnum area (FMA) and the posterior cranial fossa volume (PCFV) with the degree of cranial base synchondrosis ossification. OBJECTIVE: To illustrate these features in healthy children. METHODS: The FMA, the PCFV, and the ossification of 12 synchondroses according to the Madeline and Elster scale were retrospectively analyzed in 235 healthy children using millimeter slices on a computed tomography scan. RESULTS: The mean FMA of 6.49 cm2 in girls was significantly inferior to the FMA of 7.67 cm2 in boys (P <.001). In both sexes, the growth evolved in a 2-phase process, with a phase of rapid growth from birth to 3.75 years old (yo) followed by a phase of stabilization. In girls, the first phase was shorter (ending at 2.6 yo) than in boys (ending at 4.33 yo) and proceeded at a higher rate. PCFV was smaller in girls (P <.001) and displayed a biphasic pattern in the whole population, with a phase of rapid growth from birth to 3.58 yo followed by a phase of slow growth until 16 yo. In girls, the first phase was more active and shorter (ending at 2.67 yo) than in boys (ending at 4.5 yo). The posterior interoccipital synchondroses close first, followed by the anterior interoccipital and occipitomastoidal synchondroses, the lambdoid sutures simultaneously, then the petro-occipital and spheno-occipital synchondroses simultaneously. CONCLUSION: The data provide a chronology of synchondrosis closure. We showed that FMA and PCFV are constitutionally smaller in girls at birth (P ⩽.02) and suggest that a sex-related difference in the FMA is related to earlier closure of anterior interoccipital synchondroses in girls (P =.01).



2015 ◽  
Vol 42 (1) ◽  
Author(s):  
Magdalena Opała

Abstract An annually resolved and absolutely dated ring-width chronology spanning 443 years has been constructed using the historical and living-tree Scots pine samples from the Upper Silesia, south of Poland. The constructed regional chronology, based on six object chronologies, covers the period of 1568-2010. It is composed of 178 wood samples with the mean correlation of 0.51, mean series length of 104 years and mean EPS of 0.85. In total, 65 extreme years were distinguished. Their inde-pendent verification, based on the historical and meteorological data, showed significant correlation with the exceptionally cold/mild winters as well as severe droughts. The comparison of the extreme years with the other Polish pine chronologies showed similarities in the years with the anomalous winter conditions. Some extreme years can be associated with the exceptional pluvial conditions; these years are common in the Central European hydroclimatic tree-ring records. The construction of this regional pine chronology enables for the absolute dating of many architectural monuments from investigated region. The application of the new chronology for the dating of local wood can support interpretations of changes in the environment of the Upper Silesian region. In the future it can also be used as the basis for climate reconstruction.



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