Mean Annual Height Research Articles

Juvenile Performance of Exotic Larches in Central Wisconsin1

Abstract A permanent test plantation consisting of a single provenance of Japanese larch and six provenances of European larch was established in central Wisconsin in the spring of 1982 by hand planting 2-0 stock grown from seed originating in Europe. A randomized complete block design with seven replications was used. Altogether 294 trees (6 trees/plot X *** plots/block x 7 replications) were installed in the test. After five growing seasons in the field, plantation survival was 98%. Nineteen percent of the trees had suffered bark damage by deer, and 22% had terminals clipped by grasshoppers. The damages were not related to seed source origin, and they were of short duration. The between-seedlot differences in annual shoot elongation were statistically significant in each of three consecutive growing seasons. Mean annual height growth for both exotic larches combined was 53 cm. Mean total height reached 3.73 m after seven growing seasons (two in the nursery, five in the plantation). Early growth potential of both larches was more than three times that of native red pine planted adjacent to the larch study site. Although the single Japanese larch provenance was slowest growing, sensitive to late frost, and possessed the lowest percentage of straight stems, it still outperformed red pine. European larch of Polish provenances, combining good growth with straightness characteristics, is recommended for general planting purposes on suitable sites in central Wisconsin. North. J. Appl. For. 6(1):31-33, March 1989.

Honduras Pine Spacing Trial Results in Puerto Rico

Abstract Puerto Rico has one of the oldest, continuously measured spacing trials of Honduras pine (Pinus caribaea mor. hondurensis) in existence. At 18 to 20 years, mean survival for all the trial sites except one that suffered hurricane damage in 1979 was 82%. Survival was not related to the triangular spacing treatments of 5, 7, 10, and 14 feet. But spacing did influence diameter growth at all four sites and affected height growth at all but one site Each site had trees ≥100 feet tall at 18 to 20 years; on the two best sites, individual trees reached 90 feet by 12 years. At close spacings, mean annual height increments peaked at 4.0 to 4.5 years on two sites and at 7.2 years on the other two sites. Mean annual diameter increments peaked even earlier, at 3.0 to 3.5 years on the two good sites and at 6.0 years on the two poorer sites. Early effects of competition in reducing both mean annual height and diameter growth, particularly at close spacings, have several managerial implications. The most striking are: (1) underestimating site quality or site index if growth assessments are made only in dense stands, and (2) significant loss of wood volume over long rotations when managers fail to time thinnings before mean annual height and diameter increments decrease.

Natural and Advance Regeneration of Engelmann Spruce and Subalpine Fir Compared 21 Years After Site Treatment

The mean height of Engelmann spruce (Picea engelmanni Parry) advance growth 21 years after release by overstorey harvesting and residual tree felling, was eight times that of natural regeneration established following brush blade scarification. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.) advance growth was nine times taller than natural regeneration established on scarified soil. Mean current annual height increment of Engelmann spruce and subalpine fir advance growth was 39 and 34 cm, respectively, compared with only 7 cm for natural regeneration on scarified soil. The performance gap does not appear to be narrowing. The poor performance of natural regeneration on mineral soil exposed by blade scarification is attributed to removal of organic and top mineral soil horizons beyond the immediate reach of seedlings. These soil layers remained available to the advance growth. Consideration should be given to preserving advance growth when scarification may be inappropriate.

Changes in plasma inorganic phosphorus and alkaline phosphatase activity during the adolescent growth spurt.

Longitudinal data on changes in the concentrations of plasma inorganic phosphorus and plasma alkaline phosphatase activity in 23 girls and 44 boys during the adolescent growth spurt are reported together with the height velocities, ages and sexual maturity ratings. The average age at the peak of the growth spurt was 12.5 years in the girls and 14.1 years in the boys with mean annual height gains of 7.0 and 9.7 cm/year respectively. In both sexes, plasma alkaline phosphatase activity rose and fell with the growth velocity during the growth spurt. Plasma inorganic phosphorus rose to reach a peak in the 4 months before the peak of the growth spurt in height; this rise was statisically significant in the boys but not in the girls. Values subsequently fell rapidly towards the normal adult concentrations. Plasma calcium, total protein, and albumin concentrations were also followed during this time, but were not at any point significantly different from normal adult values. These findings provide a guide for the interpretation of plasma biochemistry in adolescent patients.

Growth of a Sitka Spruce Plantation: Analysis and Stochastic Description of the Development of the Branching Structure

(1) Three phases of canopy development were recognised during the first 15 years of a young plantation of Picea sitchensis: (i) an initial period before 'foliage overlap' (about 6 years), when the annual height increments of trees are small; (ii) accelerating annual height increments, from 'foliage overlap' to 'crown interlock' (about 11 years); (iii) stable mean annual height increment, and the establishment of a population hierarchy in height increment, following 'crown interlock'. (2) There are three component processes in the development of the branching structure of Sitka spruce: bud production, their dispersion, and subsequent extension. The factors which may control them are discussed and stochastic models are presented to describe them. Branch number production is reduced after 'foliage overlap' and subsequently varies consistently between trees but little with time. Branch dispersion is invariant throughout the forest development, the distribution around the main stem is regular, irrespective of numbers produced; the mean angle of branch production is consistent between years and its subsequent annual decline is regular. Branch extension seems to be resource limited and influenced during phase (ii) of canopy development by the number of branches produced on the tree and during phase (iii) by the position of the tree in the hierarchy which has developed.

The Mean Wind Structure over Bahrein and Aden in 1962

Abstract The mean upper wind structure over Bahrein and Aden in 1962 is studied. Patterns of the zonal and meridional wind speed components are presented. Eddy and advective fluxes of the momentum are calculated and mean annual height profiles drawn for both stations. The transport of momentum by synoptic scale eddies is more important at Bahrein than at Aden. Transport of momentum by the local mean meridional wind is larger in magnitude and fluctuates in an irregular way from month to month at both stations. The vertical integral of the momentum suggests export of relative momentum from the Bahrein-Aden sector in winter and import in summer. These conclusions are supported by 1963 data from the Ahmadabad-Madras sector. In the belt of latitude considered the winter surface winds have an easterly component and gain momentum from the earth while the summer surface winds have a westerly component and lose momentum to the earth. The results of the short period analysis for the sectors studied suggest broad ag...

Menarcheal age and the height, weight, and skeletal age of girls age 7 to 17 years

Summary This report is based on 1,339 birthday examinations of 200 Brush Foundation Regular Series girls from 7 to 17 years of age. The data used are menarcheal age; measurements of standing height and weight; skeletal age assessments made according to the Todd 1935 standards of six areas—hand, foot, elbow, knee, hip and shoulder; annual increments in height, weight, and skeletal age; weight-height index. Brush Regular Series children are, as a group, above average socio-economically. From 7 to 15 years of age the means of standing height of girls with early menarches are invariably greater than those of girls with late menarches. From 7 to 16 years of age the means of weight of girls with earlymenarches are invariably greater than those of girls with late menarches. From 7 to 16 years of age girls with early menarches are, as a group,characterized by greater weight for height than girls with late menarches. From 7 to 17 years of age the girls in the early menarcheal age groupare advanced in mean skeletal age over the girls in the average menarcheal age group, and the latter, in turn, are advanced in mean skeletal age over those in the late menarcheal age group. The year of maximum increment in standing height is related to menarchealage; the greatest mean annual height increment occurs between 10 and 11 years for girls with menarches from 10 years to 11 years, 11 months; between 11 and 12 years for girls with menarches from 12 years to 12 years, 11 months; and between 12 and 13 years for girls with menarches from 13 years to 15 years, 3 months. Values of maximum annual increments are negatively related to menarcheal age; girls with early menarches experience the greatest acceleration, followed by the greatest deceleration; girls with late menarches experience the least acceleration followed by the least deceleration. The average girl experiences her greatest height increment during the year preceding the year of menarche; maximum increment does occur during the year of menarche; it does occur during the second year preceding menarche, and some girls with late menarches seem to experience little or no premenarcheal acceleration. Maximum increment in standing height, in this series, never occurs after the menarche. For three menarcheal age groups, early, average, and late, mean maximumincrements in weight tend to be spread over a two-year period. The values of maximum increments are negatively related to menarcheal age. The decline in weight increment following the maximum is less marked than the decline in height increment; it is most marked for those with early menarches (and largest maximum increments), least marked for those with late menarches (and smallest maximum increments). Skeletal age is more highly correlated with menarcheal age than arestanding height, weight, weight-height index, or annual increments in standing height. Girls of early, average, and late menarcheal age groups can be differentiated by their assessments of skeletal maturity in advance of the menarche and in advance of the premenarcheal acceleration in height and weight. The mean menarcheal age of 187 girls for whom interpolated skeletalages at the menarche are available is 151.52 months; the mean interpolated skeletal age at menarche of these girls is 156.99 months. Chronologic age at menarche is about twice as variable as skeletal age at menarche. Fifty per cent of the 187 skeletal ages at menarche fall between ± three months of the mean, 156.99 months. It is normal for some children to grow and to develop toward maturityat a rapid rate with, consequently, an early attainment of terminal size; it is normal for some other children to grow and develop toward maturity at a slow rate with, consequently, a late attainment of terminal size. The rate of growth, in this series, has no reliable relationship to terminal size.

Recent Sea-Level Variations in Japan and Italy 1

IN a valuable memoir, Prof. Omori deals with -*o the variations in the height of the sea-level at nine mareograph stations in Japan from 1898 (in a few cases from 1894) to 1910, referred to in a note in NATURE of December 26, 1912 (vol. xc., p. 471). They are greatly in excess of any changes that might be due to variations of barometric pressure or air-temperature, and the effects of wind are probably negligible. These variations being allowed for, there remain considerable changes in the mean annual height of the sea-level at all nine stations, the greatest being a decrease in height of 22.7 mm. per year at Ayukama. In the accompa nyi ng sketch-map, the shaded areas represent the parts of Japan which are now subsiding, the boundaries inland being determined by interpolation. The figures at the different stations denote the mean annual rise or fall of the sea-level In millimetres per year. It is on the east side, to which the present depressions are chiefly confined, that the greatest depths of ocean lie and the most violent earthquakes originate.

On a cycle of eighteen years in the mean annual height of the barometer in the climate of London; and on a constant variation of the barometrical mean, according to the moon’s declination

For obtaining the general results communicated in the present paper, the author has followed the same method as that he had adopted in the two former papers laid before the Society on the connexion of the barometrical variation with the lunar phases and apsides. Tables are given of the barometrical averages on successive solar years, from 1815 to 1832, so constructed as to exhibit the variation of the moon’s influence according to her declination; and also of these averages on successive cycles of nine solar years, classed according to the moon’s place in declination, on either side of the equator. The results deduced from these comparisons are, first, that the barometrical mean in this climate is depressed by the moon’s declination being to the south of the equator; and, secondly, that this depression takes place gradually, commencing with the moon’s being in full north declination, and proceeding through her remaining positions to the time when she crosses the equator to resume the northern declination; at which season, the whole pressure that had been withdrawn from the atmosphere is suddenly restored. The author thinks there is evidence of a great tidal wave, or swell in the atmosphere, caused by the moon’s attraction, preceding her in her approach to, and following her slowly as she recedes from these latitudes; so that were the atmosphere a calm fluid ocean of air, of uniform temperature, this tide would be manifested with as great regularity as those of the ocean of waters. But the currents uniformly kept up by the sun’s varying influence effectually prevent this from taking place, and involve the problem in complexity. He finds that there is also manifested in the lunar influence a gradation of effect, which operates through a cycle of eighteen years. The mean pressure of the atmosphere during the first part of this period increases; and then, after preserving for a year its maximum amount, again decreases through the remaining years of the cycle, but exhibits, towards its minimum, some fluctuations before it again regularly increases.

XIX. On a cycle of eighteen years in the mean annual height of the barometer in the climate of London, and on a constant variation of the barometrical mean according to the Moon's declination

I have already treated this subject, partially and in detail, in the 'Climate of London.’ The further and full development of it in that way will be found an undertaking more of labour than of difficulty, the materials being already provided for doing this through a lunar cycle of eighteen years; but I am enabled, by means of these, to present to the Royal Society some general results, which will prove interesting, and probably important to the science to which they belong. The like method has been adopted in this paper as in my two former, read before the Society, on the connexion of the barometric variation with the Lunar Phases and Apsides . I have excluded, by appropriate averages, those effects of the lunar influence which belong not to the subject immediately before us. These, however, will require, whensoever we may think it time to form a theory, to be examined conjointly with the present and every other of the elements of this intricate subject.