DISTRIBUTION AND VITALITY OF XYLEM RAYS IN RELATION TO TREE LEAF AREA IN DOUGLAS-FIR

IAWA Journal ◽  
2000 ◽  
Vol 21 (4) ◽  
pp. 389-401 ◽  
Author(s):  
Barbara L. Gartner ◽  
David C. Baker ◽  
Rachel Spicer

The factors that determine sapwood width and volume in a tree are not known. This study asked whether sapwood width is related to a need for stem storage sites. Experiments were conducted on 12 34-year-old Douglas-fir [(Pseudotsuga menziesii (Mirb.) Franco] trees with a 6-7 fold range of leaf areas and leaf area/sapwood volumes. Because of declining ray frequency but constant average ray area, ray volume declined for the first 6-10 growth rings, then remained constant, and did not vary with height (breast height vs. 10 nodes from the top). Fewer of the ray parenchyma cells had nuclei in inner than outer sapwood. Inner sapwood had ray parenchyma with smaller rounder nuclei than did outer sapwood, and there was no effect of height. There was a positive relationship between leaf area and the relative volume of ray in outer sapwood at breast height (r = 0.646, p = 0.02), supporting the hypothesis that Douglas-fir trees with larger leaf areas have higher ray volume than do trees with smaller leaf areas. However, correlations of leaf area I sapwood volume with leaf area at either height were not significant, nor were correlations of either leaf area or leaf area/sapwood volume with measures of ray vitality (nuclear frequency in outer sapwood, or the ratio of nuclear frequency in the middle I outer sapwood or in inner I outer sapwood). These latter correlations give no evidence that Douglas-fir trees determine their sapwood volume based on a need for quantity of vital xylem rays.

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Gabriel U.C.A. Santos ◽  
Cátia H. Callado ◽  
Marcelo da Costa Souza ◽  
Cecilia G. Costa

Myrciaria, Neomitranthes, Plinia and Siphoneugena are closely related genera whose circumscriptions are controversial. The distinctions between Myrciaria vs. Plinia, and Neomitranthes vs. Siphoneugena, have been based on a few fruit characters. The wood anatomy of 24 species of these genera was examined to determine if wood anatomical features could help delimit the genera. It was determined the four genera cannot reliably be separated by wood anatomy alone. Characteristics seen in all four genera are: growth rings usually poorly-defined; diffuse porous; exclusively solitary vessels, usually circular to oval in outline; simple perforation plates; vessel-ray pits alternate and distinctly bordered; fibers with distinctly bordered pits in radial and tangential walls, usually very thickwalled; vasicentric tracheids typically absent; scanty paratracheal parenchyma, sometimes unilateral, and diffuse to diffuse-in-aggregates; chambered crystalliferous axial parenchyma in many species, usually both prismatic and smaller crystals; rays 1–4-seriate, uniseriate rays composed of upright/square cells, multiseriate rays with procumbent body cells and 1 to many marginal rows of upright/square cells; disjunctive ray parenchyma cells usually present.


IAWA Journal ◽  
1994 ◽  
Vol 15 (3) ◽  
pp. 323-327 ◽  
Author(s):  
K.C. Yang ◽  
Y.S. Chen ◽  
C.A. Benson

Vertical and radial variations of nuclear elongation index (NEI) of living sapwood ray parenchyrna cells were studied in a 45-year-old plantation tree of Cryptomeria japonica D. Don collected in Taiwan on February 27, 1992. Nine wood strips oriented in an E-W direction of the tree were collected starting at 0.3 m above ground level, and progressing upwards by 2.5 m intervals to the tree crown. Radial sections, 20 µm thick, were cut from the cambium toward the inner sapwood of these nine wood strips. The nuclear elongation index (NEI) was used to express the metabolic activity of the ray cells. It was found that metabolic activity of sapwood ray parenchyma was thc highest at the outer sapwood and declined gradually towards the inner sapwood. The lowest average NEI was found at the lowest stern level. The average NEI of various stern height levels increased with increasing stern height level. The average NEI of three growth rings at the outer sapwood near the cambium reached a maximum at the bottom of the live crown.


Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 977 ◽  
Author(s):  
Mirela Tulik ◽  
Joanna Jura-Morawiec ◽  
Anna Bieniasz ◽  
Katarzyna Marciszewska

This paper deals with the spatial distribution of heartwood in Scots pine stems (Pinus sylvestris L.), determined on the basis of the absence of nuclei in parenchyma cells. Samples were collected at several heights from two Scots pine stems growing in fresh coniferous stand as codominant trees. Transverse and radial sections were cut from the samples and stained with acetocarmine to detect the nuclei and with I2KI to show starch grains. Unstained sections were also observed under ultraviolet (UV) light to reveal cell wall lignification. The shapes of the nuclei in ray and axial parenchyma cells differed: the axial parenchyma cells had rounded nuclei, while the nuclei of the ray parenchyma cells were elongated. The lifespan of the parenchyma cells was found to be 16–42 years; the longest-lived were cells from the base of the stem, and the shortest-lived were from the base of the crown. The largest number of growth rings comprising heartwood was observed at a height of 1.3–3.3 m, which signifies that the distribution of heartwood within the stem is uneven. Moreover, the distance of the cells from the apical meristem and the cambium was seen to have an effect on the presence of living parenchyma cells, i.e., those with stained nuclei.


2014 ◽  
Vol 59 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Kishore S. Rajput ◽  
Bharat D. Chaudhary ◽  
Vidya S. Patil

Abstract Stems of Ipomoea obscura Ker Gawl., increase in thickness by forming multiple rings of cambia. Stems 5-6 mm thick produce parenchymatous derivatives which divide repeatedly to form small arcs of cambium. Several such small arcs initiate simultaneously and form a ring of small cambial arcs. After the formation of a few xylem and phloem elements, all these arcs are interconnected by transdifferentiation of parenchyma cells present between the cambial arcs and constitute a complete cambial cylinder. This newly formed cambium is functionally bidirectional: earlier- formed arcs produce xylem centripetally and phloem centrifugally, while later-formed segments exclusively produce thin-walled parenchyma cells on either side. Young stems are circular in cross section but as stem thickness increases they become oval to elliptic or lobed and dumbbell-shaped. Xylem rays are mostly uni- or biseriate and thin-walled, but multiseriate rays characteristic for a climbing habit are observed occasionally. In thick stems, the marginal ray parenchyma in most of the samples becomes meristematic and develops ray cambia which exclusively produce sieve elements. Similarly, parenchyma cells produced from later-formed cambial segments give rise to several irregularly oriented vascular bundles. The secondary xylem is diffuse porous, with indistinct growth rings and is composed of fibriform and wider vessels, fibres, and axial and ray parenchyma cells, while phloem consists of sieve elements, companion cells, and axial and ray parenchyma cells.


IAWA Journal ◽  
2009 ◽  
Vol 30 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Pat Denne ◽  
Siân Turner

Differences between the ray structure of rootwood and stemwood were analysed in 11 species from 5 families of gymnosperms. Rootwood was consistently found to have fewer ray tracheids, with ray parenchyma cells which were taller axially, wider tangentially, but shorter radially, and had more pits per cross-field than stemwood. A scale for quantifying types of cross-field pitting is proposed, and statistically significant differences in type and diameter of cross-field pitting were found between rootwood and stemwood of most species sampled. These structural differences have practical implications for identification of gymnosperm roots, and for distinguishing between rootwood and stemwood.


IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Pat Denne ◽  
Peter Gasson

Differences in ray structure between root- and stem-wood of softwoods can cause confusion in identifying roots using keys based on stem-wood anatomy. Comparison of root- and stem-wood rays of Larix decidua showed root-wood had fewer ray tracheids, taller, wider but shorter ray parenchyma cells, and larger cross-field pits than stem-wood. The implications of these differences are considered in relation to the identification and function of roots.


2008 ◽  
Vol 54 (No. 7) ◽  
pp. 321-332 ◽  
Author(s):  
P. Kantor

: The study evaluates production parameters (height, diameter at breast height, volume) of Douglas fir (<I>Pseudotsuga menziesii</I> [Mirb.] Franco) at mesotrophic sites of the Křtiny Training Forest Enterprise in mature stands. In total, 29 mixed stands were assessed with the registered proportion of Douglas fir at an age of 85 to 136 years. Comparing the 10 largest Douglas firs with the 10 largest spruces or larches higher, and as a rule markedly higher, production potential of introduced Douglas fir was found in all assessed stands. There were also groups of trees where the volume of Douglas fir was twice to 3 times higher than the volume of spruce or larch (see Tabs. 5 to 10). For example, in stand 177B11, the mean volume of 9.12 m<sup>3</sup> was recorded in the 10 largest Douglas fir trees but the volume of spruce reached only 3.17 m<sup>3</sup> and the volume of larch was 3.70 m<sup>3</sup>. Differences in mensurational parameters of Douglas fir found on the one hand and of Norway spruce (<I>Picea abies</I> [L.] Karst.) or European larch (<I>Larix decidua</I> Mill.) on the other hand compared by ANOVA tests were statistically highly significant. Annual ring analyses have shown that at present the volume increment of particular Douglas fir trees ranges from 0.12 to 0.16 m<sup>3</sup> per year in mature stands (i.e. about 1.5 m<sup>3</sup> every 10 years).


1990 ◽  
Vol 5 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann

Abstract A segmented polynomial taper equation for southwestern Oregon Douglas-fir (Pseudotsuga menziesii) predicts double bark thickness (dbt) at any point above breast height. Below breast height predictions assume conformity to a neiloid frustrum. The equations facilitate estimation of inside bark diameter (dib) given outside bark (dob) measurements. Bark volume and bark biomass can also be estimated when supplemented with existing dib taper equations developed for southwestern Oregon. West J. Appl. For. 5(1):5-8.


IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Yasuaki Sakamoto ◽  
Yuzou Sano

Water conduction and wood anatomy of Salix sachalinensis attacked by watermark disease were investigated. The internal symptom, the watermark, appeared as a brown to brown-black stained zone in sapwood. Dye injection tests revealed that water conduction did not take place in the watermark. However, soft X-ray photography and cryo-scanning electron microscopy revealed that the watermark had a high moisture level. In the watermark, some of the vessels were plugged with tyloses and masses of bacteria, and some of the ray parenchyma cells caused necrosis. Hence, the non-conductive watermark in sapwood can be considered similar to discoloured wood or wetwood.


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