Crown architecture of Larix laricina saplings: sylleptic branching on the main stem

1985 ◽  
Vol 63 (7) ◽  
pp. 1296-1302 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Growth Increment ◽  
Height Growth ◽  
Shoot Length ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Branching Patterns ◽  
Architectural Model ◽  
Long Shoots ◽  
Lateral Branches ◽  
Architectural Characteristics

Sylleptic branching occurred on the current (1983) height-growth increment in 44% of Larix laricina (Du Roi) K. Koch (tamarack) saplings sampled from a natural population near Fredericton, N.B. Although variable, the occurrence and amount of syllepsis tended to increase with parental shoot length. Sylleptic shoots were generally located on the proximal halves of parental shoots. In most cases, the proximally and distally situated sylleptic shoots were somewhat shorter than those in between. The lengths of terminal shoots arising from sylleptic shoots were significantly correlated with parental shoot length, current tree leader length, and location of the branch on its parental shoot. The lengths and elevation angles of terminal extensions from sylleptic shoots tended to be greater than those from nonsylleptic (proleptic) lateral long shoots borne in the same region of the height-growth increment. Architectural characteristics of the extensions resembled those of the more distal proleptic shoots, which develop into major branches. Thus, an additional complement of major lateral branches appeared to be developing where syllepsis occurred. Quantitative relationships depicting sylleptic branching patterns were incorporated into a previous architectural model and simulations of crown architecture which included syllepsis were obtained.

Crown architecture of Larix laricina saplings: shoot preformation and neoformation and their relationships to shoot vigour

1984 ◽  
Vol 62 (11) ◽  
pp. 2181-2192 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Leaf Primordia ◽  
Shoot Length ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Short Shoot ◽  
Shoot Buds ◽  
Lateral Buds ◽  
Lateral Bud ◽  
Long Shoots ◽  
Terminal Buds

Resting buds from five locations on long shoots in each of six crown positions were compared for 30 Larix laricina (Du Roi) K. Koch saplings. At each locus, bud sizes, numbers of bud scales and preformed leaf primordia (basal and axial for long-shoot buds), and apical widths were positively related to parent-shoot length. Along individual shoots, (i) terminal and lateral long-shoot buds contained fewer basal-leaf primordia than the more proximal short-shoot buds; (ii) terminal buds contained the most bud scales and axial-leaf primordia; and (iii) numbers of bud scales increased, while numbers of axial-leaf primordia generally decreased, basipetally among lateral buds. Comparison of bud leaf content with leaves on elongated shoots by regression showed that numbers of preformed and neoformed leaves increased with shoot length, but numbers of neoformed leaves did so to a greater degree. Internode lengths, numbers of leaves per lateral bud produced, and leaf lengths were greater on neoformed than on preformed shoot segments. Because of their capacity for neoformed growth following preformed growth and because of increases in internode lengths among all axial leaves, shoots from subjacent lateral buds replaced experimentally decapitated tree leaders (terminal buds) in one season, with little or no loss of height growth.

Crown architecture of Larix laricina saplings: quantitative analysis and modelling of (nonsylleptic) order 1 branching in relation to development of the main stem

1984 ◽  
Vol 62 (9) ◽  
pp. 1904-1915 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Morphological Variability ◽  
Natural Populations ◽  
Height Growth ◽  
Main Stem ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Growth Increments ◽  
Long Shoots ◽  
Architectural Models ◽  
Short Shoots

The upper 5 years of crown growth in samples of Larix laricina (Du Roi) K. Koch (tamarack) saplings from natural populations in the Fredericton, N.B., area provided data to model architectural relationships describing patterns of (nonsylleptic) order 1 branching in relation to development of the main stem. The model was based on relationships between branch extension and height growth, and numbers and positions of order 1 branches. Elevation angles of shoots making up the branches, and conversion of order 1 long shoots to order 1 short shoots were also incorporated. Lengths of current shoots of major order 1 branches tended to decrease with increasing depth in the crown. Similar tendencies occurred among lengths of all current branch extensions within single height-growth increments, but the decreases in length became less regular with increasing age of branch. Because the relationships were complex, alternative approaches to modelling shoot lengths were adopted to enhance understanding of the patterns involved. Deterministic and stochastic elements were used in the overall model to account for significant proportions of morphological variability. Simulations based on the alternatives within the model were realistic in their interpretations of actual sapling crown architecture. Classification of L. laricina according to previously proposed architectural models that qualitatively describe general development was discussed.

Crown architecture of Larix laricina saplings: an analysis of higher order branching

1987 ◽  
Vol 65 (2) ◽  
pp. 268-279 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Simulation Modelling ◽  
Shoot Length ◽  
Larix Laricina ◽  
Structural Development ◽  
Short Shoot ◽  
Lateral Buds ◽  
Architectural Patterns ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Shoot

Quantitative analysis and simulation modelling of Larix laricina (Du Roi) K. Koch branches revealed a complex system of architectural patterns and correlations. Numbers of lateral buds and long shoots were positively correlated with parent-shoot length, but the relationships varied among shoot orders and for sylleptic shoots. For order 2 and sylleptic shoots, numbers of lateral long shoots were also correlated with associated terminal-shoot lengths. Sylleptic shoots produced more lateral long shoots than equivalent proleptic shoots. Lateral long-shoot lengths decreased basipetally and were correlated with terminal-shoot lengths. Lengths of order 2 lateral long shoots also varied independently with crown position. Generally, the degree of apical control decreased and the proportion of short shoots increased with positions of less vigour in the crown. Terminal long-shoot lengths varied with parent-shoot length, location, and to some extent parent-axis leader length. Terminal short-shoot production was associated with shorter parent shoots. Shorter order 2 shoots (<60 mm) and most order 3 shoots produced no lateral long shoots. The net result was that branch structural development ceased in less vigorous crown positions. The spatial disposition of shoots, as defined by elevation and divergence angles, varied with position of origin around and along parent shoots. Although variable, elevation angles decreased and divergence angles increased basipetally.

scholarly journals The effect of nitrogen on growth and architecture of Fraxinus pennsylvanica 'Patmore' (green ash) in Field-grow containers at two sites in Manitoba, Canada

1996 ◽  
Vol 76 (4) ◽  
pp. 825-833 ◽  
Author(s):  
W. R. Remphrey ◽  
C. G. Davidson
Keyword(s):  
Growth And Development ◽  
Growth Increment ◽  
Height Growth ◽  
Shoot Length ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Growing Seasons ◽  
Lateral Shoots ◽  
N Treatment ◽  
Four Levels

Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. 'Patmore' green ash was established at two sites in southern Manitoba. Four levels of N fertilizer (4.5–400 ppm) were applied during two growing seasons. Growth and development of the trees was dependent on the site and local environmental conditions. At Morden, the annual height growth increment was greater with lower levels of N applications and declined at higher levels, while at Winnipeg higher levels resulted in greater growth. Stem diameter changes followed a similar pattern. The numbers of lateral shoots per parent shoot were only weakly affected by N treatment and any differences appeared to be an indirect effect of parental shoot length. The Field-grow containers at the Winnipeg site were installed in crass-sod which penetrated the containers and appeared to result in competition for N resources. The Morden site was kept cultivated and thus there was no such competition. At Morden, it is possible that wicking from the surrounding soil may have moved excessive salts into the containers resulting in high conductivity values and toxicity. Key words: Field-grow, biomass, roots, architecture, fertilization, Fraxinus pennsylvanica

Syllepsis in Larixlaricina: association of sylleptic branching with cross-sectional stem growth and stem form of saplings

1987 ◽  
Vol 17 (12) ◽  
pp. 1609-1619 ◽  
Author(s):  
W. D. McCurdy ◽  
G. R. Powell
Keyword(s):  
Growth Increment ◽  
Stem Growth ◽  
Main Stem ◽  
Stem Form ◽  
Cross Sectional ◽  
Long Shoots ◽  
Plus Tree ◽  
Stem Development ◽  
Lateral Branches

The effect of sylleptic branching on past stem growth of 8-year-old Larixlaricina (Du Roi) K. Koch saplings was investigated in relation to the lengths of long shoots borne on sylleptically and proleptically originated lateral branches over a 4-year period. Over time, the sylleptic crown component accounted for increasing proportions of the total crowns of saplings exhibiting syllepsis. The total length of all long shoots in the crown increased linearly from lightly to heavily sylleptic saplings. However, groups of branches of sylleptic origin declined in average shoot vigour more rapidly than did groups of branches of proleptic origin in the same height-growth increment. Annual wood ring production and total stem cross-sectional areas at various positions along the main stem were positively correlated with the proleptic, sylleptic, and total branching components occurring above those positions. Wood production along the stem was greater, more uniform and the resultant stem more conical in heavily sylleptic saplings than in lightly sylleptic saplings. The role of syllepsis in crown and main stem development was discussed in relation to plus-tree selection for tree improvement purposes.

Crown architecture of short-rotation, intensively cultured Populus II. Branch morphology and distribution of leaves within the crown of Populus 'Tristis' as related to biomass production

1982 ◽  
Vol 12 (4) ◽  
pp. 853-864 ◽  
Author(s):  
J. G. Isebrands ◽  
N. D. Nelson
Keyword(s):  
Leaf Area ◽  
Growth Increment ◽  
Height Growth ◽  
Intensive Culture ◽  
Short Rotation ◽  
Long Shoots ◽  
Short Shoots ◽  
Old Trees ◽  
The Relationship ◽  
Branch Morphology

The branch morphology and the distribution of leaves and specific leaf weight were determined within the crown of 5- and 6-year-old Populus 'Tristis No. 1' (P. tristis Fisch. × P. balsamifera L.) trees grown in northern Wisconsin under short-rotation, intensive culture at 1.2- and 0.6-m square spacings, respectively. The relationship of leaf area to aboveground biomass productivity was also evaluated for the same trees. The first-order branches within the trees exhibited acrotony and were predominantly long shoots. No branching higher than third-order was observed. Leaf size and specific leaf weight were greatest on the current terminal shoot and decreased from the upper portion of the crown to the base. When the 6-year-old trees were divided into eight 1-m vertical strata, over 80% of the total number of leaves and total leaf area was in three middle strata (4–7 m), and most of the 1-m strata contained leaf area attached to two or more height growth increments. Leaves attached to branches on a single height growth increment of the 6-year-old trees occurred in up to four 1-m vertical strata. Long shoots comprised 53% of total leaf area in the 5-year-old trees and 66% in the 6-year-old trees, short shoots the remainder. Ninety-five percent of the long shoots in the 6-year-old trees were in the three uppermost vertical strata (5–8 m), and 95% of the short shoots were in the lowermost leaf-containing vertical strata (3–6 m). Long-shoot leaves had higher specific leaf weights than short-shoot leaves attached to branches on the same height growth increment. Leaf-area indices (LAI) were 7.6 and 8.8 m2•m−2 for the 5- and 6-year-old stands, respectively. Leaf area per tree was linearly related to the aboveground biomass of the tree. The linear regression line for the relationship between leaf area and D2H (diameter2 × height) for the 6-year-old trees in the study was statistically different from that of the 5-year-old-trees. The data presented suggest that this relationship may serve as a useful quantitative index of crown closure in poplar stands. The results also suggest some crown morphological criteria useful for selection and breeding of improved poplar trees for short-rotation intensive culture.

SEASONAL GROWTH CHARACTERISTICS OF LONG AND SHORT SHOOTS OF TAMARACK

1967 ◽  
Vol 45 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
J. Johanna Clausen ◽  
T. T. Kozlowski
Keyword(s):  
Seasonal Changes ◽  
Stem Elongation ◽  
Growth Characteristics ◽  
Weight Increase ◽  
Stem Length ◽  
Larix Laricina ◽  
Seasonal Growth ◽  
Long Shoots ◽  
Short Shoots ◽  
Food Reserves

Tamarack (Larix laricina (DuRoi) K. Koch) produces long shoots which bear two kinds of needles. Early needles are present in the bud and elongate rapidly after budbreak. Late needles, few of which are present in the bud, elongate later than early needles. Short shoots bear early needles only, and stem length seldom exceeds 1 mm. Seasonal changes in length and weight of needles and stems of both shoot types were measured. In long shoots, 75% of stem elongation, more than 70% of stem weight increment, and 65–70% of late needle elongation occurred after early needles were full-sized. Stem and late needle elongation ceased simultaneously, after which time needle weight decreased and stem weight increased. Early needles probably drew on food reserves while developing, and then themselves contributed to stem and late needle elongation. Final stem weight increase probably used photosynthate from both late and early needles of the current year.Shading of current and last year's needles showed that shoots in which photosynthesis was interrupted in this way produced shorter, lighter-weight stems than did control shoots.

scholarly journals Comparative Height Growth of Eastern Larch and Black Spruce in Northwestern Ontario

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Larix Laricina ◽  
Stem Analysis ◽  
Northwestern Ontario ◽  
Analysis Methods ◽  
Spruce Stands

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.

Spatial distribution and morphology of shoots in the variant crown form of Rhododendron reticulatum

Botany ◽  
2010 ◽  
Vol 88 (11) ◽  
pp. 995-1005 ◽  
Author(s):  
Kenichi Yoshimura
Keyword(s):  
Spatial Distribution ◽  
Functional Differentiation ◽  
Forest Understory ◽  
Width Ratio ◽  
Crown Architecture ◽  
Western Japan ◽  
Long Shoots ◽  
Short Shoots ◽  
Lower Depth ◽  
Crown Form

Rhododendron reticulatum D. Don ex G.Don is a common understory shrub in western Japan that exhibits highly plastic crown architecture and occurs in various light environments. I investigated how functional differentiation and spatial distribution of long and short shoots contribute to the plasticity of crown architecture of R. reticulatum. Crown form was derived from the crown depth/width ratio. Crown depth/width ratio was higher in sun-lit crowns. In crowns with higher depth/width ratio, long shoots were distributed in upper positions of the crown. Long shoots grew vertically and horizontally. In crowns with lower depth/width ratio, long shoots were arranged in the outer position of the crown and grew outward. Within neighboring shoots, long shoots had less mass than their paired short shoots. Results suggest that long shoots of R. reticulatum function to expand the crown and to reduce leaf overlap in multilayer crowns, which are found in high-light environments, while both long and short shoots function to minimize leaf overlap in monolayer crowns, which are found in shaded environments. Plasticity of crown architecture by altering shoot position and shoot morphology allows growth under various light environments in the forest understory.

Light threshold for optimal black spruce (Piceamariana) seedling growth and development under brush competition

1994 ◽  
Vol 24 (8) ◽  
pp. 1629-1635 ◽  
Author(s):  
Robert Jobidon
Keyword(s):  
Tree Growth ◽  
Black Spruce ◽  
Growth Increment ◽  
Height Growth ◽  
Light Interception ◽  
Stem Diameter ◽  
Tree Seedlings ◽  
Relative Growth ◽  
Competing Vegetation ◽  
Total Height

Light threshold is suggested as a method for quantifying brush competition in black spruce (Piceamariana (Mill.) B.S.P) plantations and predicting losses in tree growth as measured by the relative growth rate (RGR). The severity of the competing vegetation (expressed in terms of density and height) around 300 planted tree seedlings, and the growth status of the seedlings (expressed in terms of total height and current height growth increment), were analyzed simultaneously with multivariate analysis of variance (MANOVA), with one level of light quantity (photosynthetically active radiation) reaching the upper one-half of the tree seedlings as the predictor variable. This study showed that it is possible to establish a competitive status based on light interception, thus allowing a grouping of seedlings with similar growth characteristics and severity of competition. Canonical analysis showed that 60% of full sunlight reaching the upper one half of spruce seedlings can be defined as a threshold to significantly discriminate between stressed and unstressed tree seedlings, based on the above-mentioned variables and also based on spruce basal stem diameter. For spruce total height, current height increment, and basal stem diameter, significant differences were found between plots above and below this threshold, averaging 18.5, 44.7, and 23.2%, respectively. Measuring the intensity of light reaching the upper one half of the spruce seedlings also significantly explains spruce relative growth rates, expressed in terms of height growth increment and basal stem diameter growth increment over the following two growing seasons. The light threshold used in the MANOVA and the ANOVA showed significant differences between plots above and below the threshold, averaging 70 and 58% for spruce height and basal stem diameter RGRs, respectively. Instead of measuring competing vegetation variables and relative height of a crop species to infer light interception, this study demonstrated that a direct measure of light attenuation at the tree seedling level can be used to assess the competitive status and predict losses in tree growth for the period of time required by the seedlings to emerge from the vegetation cover. Moreover, this study demonstrated that canonical relations, rather than linear relations, explain the pattern of competition for light between young spruce seedlings and brushlike vegetation. The light threshold suggested in this study has potential for assessing interspecific competition problems in young black spruce plantations and is proposed as a tool to support a containment strategy of vegetation management.

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