Leaf area – sapwood cross-sectional area relationships in repressed stands of lodgepole pine

1987 ◽  
Vol 17 (3) ◽  
pp. 205-209 ◽  
Author(s):  
M. G. Keane ◽  
G. F. Weetman
Keyword(s):  
Hydraulic Conductivity ◽  
Leaf Area ◽  
Wood Density ◽  
Lodgepole Pine ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Density Profiles ◽  
Individual Tree ◽  
Individual Trees

To better understand the phenomenon of growth "stagnation" in high-density lodgepole pine (Pinuscontorta Dougl. ex Loud.), leaf area and its relationship with sapwood cross-sectional area were examined on both an individual tree and stand basis. Leaf areas of individual trees in a 22-year-old stand varied from 30.8 m2 (dominants in stands of low stocking) to 0.05 m2 (suppressed trees in stands of high stocking). Leaf area indices ranged from 13.4 to 2.3 m2 m−2 between low and high stocking levels, respectively. Over the same stocking range, the ratio of leaf area to sapwood cross-sectional area was reduced from 0.3 to 0.15 m2 cm−2. Intraring wood density profiles showed that ovendry density increased from 0.52 to 0.7 g cm−3 and the proportion of early wood decreased over a stocking level range of 6500–109 000 trees/ha. A reduction in hydraulic conductivity in the stems of stagnant trees, suggested by the greater proportion of narrow-diameter tracheids present, may lead to a greater resistance to water transport within the boles of trees from stagnant stands, leading to low leaf areas.

Estimating leaf area of Abieslasiocarpa across ranges of stand density and site quality

1989 ◽  
Vol 19 (7) ◽  
pp. 930-932 ◽  
Author(s):  
James N. Long ◽  
Frederick W. Smith
Keyword(s):  
Leaf Area ◽  
Species Differences ◽  
Stand Density ◽  
Cross Sectional Area ◽  
Site Quality ◽  
Sectional Area ◽  
Cross Sectional ◽  
Breast Height ◽  
Unbiased Estimates ◽  
Stand Conditions

For a given species, differences in the relation between leaf area and sapwood cross-sectional area at breast height have been attributed to the effects of varying stand density and site quality. When leaf area of Abieslasiocarpa (Hook.) Nutt. is estimated as a function of sapwood cross-sectional area at breast height and distance from breast height to the midpoint of the crown, the apparent effects of stand density and site quality are eliminated. A comparison of these results with those for Pinuscontorta Dougl. suggests this model form should provide unbiased estimates of leaf area for a variety of species and stand conditions.

scholarly journals RELATIONSHIPS OF LEAF AREA AND TRUNK DIAMETER OF APPLE TREES AFFECTED BY ROOTSTOCK AN D CULTIVAR

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1169c-1169
Author(s):  
Curt R. Rom ◽  
Renae E. Moran
Keyword(s):  
Leaf Area ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Mature Trees ◽  
Apple Trees ◽  
Cross Sectional ◽  
Trunk Diameter ◽  
Yield Efficiency ◽  
Linear Relationships ◽  
Old Trees

Trunk cross-sectional area (TCA) has been used to estimate leaf area (LA) and yield efficiency but variation in LA and TCA relationships have been unexplored. LA and TCA of 10-yr-old 'Starkspur Supreme Delicious' on 9 rootstocks (STKs) were measured in 1989. LA and TCA of 2-yr-old trees of 3 cultivars (CVs) on 5 STKs were measured in 1991. Regression of LA and TCA was performed for each CV, STK and each CV/STK. On mature trees, LA varied significantly with STK. The number and LA of shoot leaves (LVS) and spur LVS varied with STK but the % of total was not significantly different (approx. 52% spur LVS). The relationships of LA and TCA were linear for mature (r2=.94) and young (r2=.44) trees. On young trees, TCA varied with CV, but LA did not. Both LA and TCA were significantly different among STKs. The linear relationships of LA and TCA had unique intercepts with each CV, STK and CV/STK combination but slopes were not significantly different. Leaf area of Jonagold' and 'Gala' tended to increase more with increasing TCA than 'Empire'.

Influence of fertilization on the allometric relations for two pines in contrasting environments

1993 ◽  
Vol 23 (8) ◽  
pp. 1704-1711 ◽  
Author(s):  
Stith T. Gower ◽  
Brent E. Haynes ◽  
Karin S. Fassnacht ◽  
Steve W. Running ◽  
E. Raymond Hunt Jr.
Keyword(s):  
Leaf Area ◽  
Ponderosa Pine ◽  
Cross Sectional Area ◽  
Red Pine ◽  
Stem Diameter ◽  
Sectional Area ◽  
Cross Sectional ◽  
Breast Height ◽  
Allometric Relations ◽  
And Control

The objective of this study was to examine the effect of fertilization on the allometric relations for red pine (Pinusresinosa Ait.) and ponderosa pine (Pinusponderosa Dougl. ex Laws.) growing in contrasting climates. After 2 years of treatment, fertilization did not significantly affect the allometric relations between stem or branch mass and stem diameter for either species. For a similar-diameter tree, current foliage mass and area and new twig mass were significantly greater for fertilized than for control red pine and ponderosa pine. The significant increase in new foliage mass and area occurred in the upper and middle canopy for red pine and middle and lower canopy for ponderosa pine. For a similar-diameter tree, projected (one-sided) leaf area and total foliage mass were significantly greater for fertilized than for control red pine. However, leaf area and total foliage mass did not differ between similar-diameter fertilized and control ponderosa pine because fertilization decreased leaf longevity. The ratios of leaf area/sapwood cross-sectional area measured at breast height (1.37 m) were 0.14 and 0.11 for control plus fertilized red pine and ponderosa pine, respectively, and were greater (but not significantly) for fertilized than for control trees, while the ratios of leaf area/sapwood cross-sectional area measured at the base of live crown were significantly greater for fertilized than for control red pine and ponderosa pine.

scholarly journals A Method for Quantifying Whole-tree Pruning Severity in Mature Tall Spindle Apple Plantings

HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1233-1240 ◽  
Author(s):  
James R. Schupp ◽  
H. Edwin Winzeler ◽  
Thomas M. Kon ◽  
Richard P. Marini ◽  
Tara A. Baugher ◽  
...  
Keyword(s):  
Leaf Area ◽  
Fruit Size ◽  
Titratable Acidity ◽  
Severity Index ◽  
Cross Sectional Area ◽  
Soluble Solids ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross ◽  
Whole Tree

Pruning is the cutting away of vegetation from plants for horticultural purposes. Pruning is known to reduce apple tree size, increase fruit size and quality, and decrease yield. Methods for studying the effects of varying degrees of severity of pruning on a whole-tree basis have used qualitative descriptions of treatments rather than repeatable whole-tree quantitative metrics. In this study, we introduce a pruning severity index calculated from the sum of the cross-sectional area of all branches on a tree at 2.5 cm from their union to the central leader divided by the cross-sectional area of its central leader at 30 cm from the graft union. This limb to trunk ratio (LTR) was then modified by successively removing the largest branches of ‘Buckeye Gala’ to achieve six severity levels ranging from LTR 0.5 to LTR 1.75, with lower values representing more extreme pruning with less whole-tree limb area relative to trunk area. Pruning treatments were applied for three consecutive years and tree growth and cropping responses were observed for the first 2 years. With increasing pruning severity the following characteristics increased after seasonal growth: number of renewal limbs, number of shoots, shoot length, number of shoot leaves, shoot leaf area, final fruit set, fruit size, yield of large fruit, crop value from large fruit, soluble solids, and titratable acidity. The following characteristics decreased: limb age, number of secondary limbs, number of spurs, number of spur leaves, spur leaf area, the ratio of spur leaf area to shoot leaf area, fruit count per tree, yield, yield efficiency, crop value from small fruit, overall crop value, and sugar:acid ratio. The LTR provides a measurable way to define and create different levels of pruning severity and achieve consistent outcomes. This allows a greater degree of accuracy and precision to dormant pruning of tall spindle apple trees. The use of the LTR to establish the level of pruning severity allows the orchard manager to set crop load potential through regulation of the canopy bearing surface. This metric is also a necessary step in the development of autonomous pruning systems.

An antithetic variate to facilitate upper-stem height measurements for critical height sampling with importance sampling

2013 ◽  
Vol 43 (12) ◽  
pp. 1151-1161 ◽  
Author(s):  
Thomas B. Lynch ◽  
Jeffrey H. Gove
Keyword(s):  
Importance Sampling ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Sample Point ◽  
Sectional Area ◽  
Critical Height ◽  
Cross Sectional ◽  
Individual Tree ◽  
Sample Tree ◽  
The Cross

Critical height sampling (CHS) estimates cubic volume per unit area by multiplying the sum of critical heights measured on trees tallied in a horizontal point sample (HPS) by the HPS basal area factor. One of the barriers to practical application of CHS is the fact that trees near the field location of the point-sampling sample point have critical heights that occur quite high on the stem, making them difficult to view from the sample point. To surmount this difficulty, use of the “antithetic variate” associated with the critical height together with importance sampling from the cylindrical shells integral is proposed. This antithetic variate will be u = (1 − b/B), where b is the cross-sectional area at “borderline” condition and B is the tree’s basal area. The cross-sectional area at borderline condition b can be determined with knowledge of the HPS gauge angle by measuring the distance to the sample tree. When the antithetic variate u is used in importance sampling, the upper-stem measurement will be low on tree stems close to the sample point and high on tree stems distant from the sample point, enhancing visibility and ease of measurement from the sample point. Computer simulations compared HPS, CHS, CHS with importance sampling (ICHS), ICHS and an antithetic variate (AICHS), and CHS with paired antithetic varariates (PAICHS) and found that HPS, ICHS, AICHS, and PAICHS were very nearly equally precise and were more precise than CHS. These results are favorable to AICHS, since it should require less time than either PAICHS or ICHS and is not subject to individual-tree volume equation bias.

scholarly journals (323) Alternate Approaches for Evaluating Horticultural Efficiency

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1038C-1038
Author(s):  
Timothy L. Righetti ◽  
Carmo Vasconcelos ◽  
David R. Sandrock ◽  
Samuel Ortega ◽  
Yerko Moreno
Keyword(s):  
Leaf Area ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Improvement Potential ◽  
Canopy Area ◽  
Alternate Assessments ◽  
Physiological Differences ◽  
The Difference ◽  
The Relationship

Four ratio-based efficiency expressions (yield/trunk cross-sectional area, yield/canopy area, yield/pruning weight, CO2 assimilation/leaf area) were evaluated. These expressions depend on the size of the denominator if the function describing the relationship between the denominator and the numerator has a non-zero intercept. When this occurs, it is difficult to determine if statistically different efficiency expressions reflect physiological differences or are caused by comparing expressions with different sized denominators. When denominators and numerators of efficiency expressions are plotted, the edge of the data cloud can often be statistically identified. The function describing the edge of the data cloud defines the maximum possible value (MPV) obtainable for a given value of the denominator. The percentage of MPV (%MPV) is an alternate efficiency expression that is not influenced by differing trunk cross-sectional area, canopy area, pruning weight, or leaf area. The difference between MPV and observed performance can be used to define improvement potential (IP). These alternate assessments can supplement traditional efficiency expressions. It is also possible to determine if statistical differences in traditional efficiency expressions are caused by differences in potential, differences in a plant or leaf's ability to achieve its potential, or differences in the size of the efficiency expression denominators.

Functional significance of the nodal constricted zone in Populus deltoides

1978 ◽  
Vol 56 (7) ◽  
pp. 801-804 ◽  
Author(s):  
Philip R. Larson ◽  
J. G. Isebrands
Keyword(s):  
Hydraulic Conductivity ◽  
Functional Significance ◽  
Populus Deltoides ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nodal Region ◽  
Poiseuille Equation ◽  
Area Data

A zone of minimum vessel number and vessel cross-sectional area (the constricted zone) occurs in the nodal region of each of the three vascular traces serving a leaf of Populus deltoides Bartr. When the area data are transformed to Σr4, they can be used in the Poiseuille equation to estimate hydraulic conductivity. The decrease in xylem conductivity frequently observed at vascular junctions, such as the nodal constricted zone, may be accounted for by a restriction in hydraulic conductivity.

Evidence that branches of evergreen angiosperm and coniferous trees differ in hydraulic conductance but not in Huber values

2007 ◽  
Vol 85 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Christopher H. Lusk ◽  
Mylthon Jiménez-Castillo ◽  
Nicolás Salazar-Ortega
Keyword(s):  
Leaf Area ◽  
Rain Forest ◽  
Temperate Forests ◽  
Hydraulic Conductance ◽  
Structure And Function ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Hydraulic Efficiency ◽  
Cross Sectional ◽  
And Function

The hydraulic efficiency conferred by vessels is regarded as one of the key innovations explaining the historical rise of the angiosperms at the expense of the gymnosperms. Few studies, however, have compared the structure and function of xylem and their relationships with foliage traits in evergreen representatives of both groups. We measured sapwood cross-sectional area, conduit diameters, hydraulic conductance, and leaf area of fine branches (2.5–7.5 mm diameter) of five conifers and eight evergreen angiosperm trees in evergreen temperate forests in south-central Chile. Conductance of both lineages was higher at Los Lleuques, a warm temperate site with strong Mediterranean influence, than in a cool temperate rain forest at Puyehue. At a common sapwood cross-sectional area, angiosperm branches at both sites had greater hydraulic conductance (G) than conifers, but similar leaf areas. Branch conductance normalized by subtended leaf area (GL) at both sites was, therefore, higher in angiosperms than in conifers. Hydraulically weighted mean conduit diameters were much larger in angiosperms than in conifers, although this difference was less marked at Puyehue, the cooler of the two sites. Conduits of the vesselless rain forest angiosperm Drimys winteri J.R. & G. Forst were wider than those of coniferous associates, although narrower than angiosperm vessels. However, GL of D. winteri was within the range of values measured for vesselbearing angiosperms at the same site. The observed differences in xylem structure and function correlate with evidence that evergreen angiosperms have higher average stomatal conductance and photosynthetic capacity than their coniferous associates in southern temperate forests. Comparisons of conifers and angiosperm branches thus suggest that the superior capacity of angiosperm conduits is attributable to the development of higher gas-exchange rates per unit leaf area, rather than to a more extensive leaf area. Results also suggest that the tracheary elements of some vesselless angiosperms differ in width and hydraulic efficiency from conifer tracheids.

Leaf area and tree increment dynamics of even-aged and multiaged lodgepole pine stands in Montana

1999 ◽  
Vol 29 (6) ◽  
pp. 687-695 ◽  
Author(s):  
Cassandra L Kollenberg ◽  
Kevin L O'Hara
Keyword(s):  
Leaf Area ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Stem Volume ◽  
Age Classes ◽  
Cross Sectional ◽  
Individual Tree ◽  
Area Index ◽  
Volume Increment

Age structure and distribution of leaf area index (LAI) of even and multiaged lodgepole pine (Pinus contorta var. latifolia Engelm.) stands were examined on three study areas in western and central Montana. Projected leaf area was determined based on a relationship with sapwood cross-sectional area at breast height. Stand structure and LAI varied considerably between individual plots. LAI and stand stem volume increment were significantly higher in multiaged than even-aged stands with the exception of one study area, which had higher volume increment in even-aged stands. Older cohorts and higher canopy strata generally had greater LAI than younger cohorts and lower strata. Ratios of stem volume increment to leaf area were used to assess stand, cohort, and individual tree vigor or growing space efficiency (GSE). Even-aged stands had significantly higher GSEs in individual study areas and overall than multiaged stands. Cohort GSE generally increased with increasing age of the cohort. Stand increment was weakly associated with stand LAI. Individual tree volume increment was strongly related to projected leaf area when stands were divided by age-classes or canopy strata. These results suggest separating these stands into components, such as age classes or canopy strata, and summing predicted increment for each component may provide more accurate prediction of stand increment than using whole-stand LAI.

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