scholarly journals GROWTH-RING DISTINCTNESS AND BOUNDARY ANATOMY VARIABILITY IN TROPICAL TREES

IAWA Journal ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 275-S7 ◽  
Author(s):  
Yegor Tarelkin ◽  
Claire Delvaux ◽  
Maaike De Ridder ◽  
Thomas El Berkani ◽  
Charles De Cannière ◽  
...  

The phenomenon of distinct, absent or indistinct growth rings is a highly variable feature used for wood identification and a wide range of tree-ring studies. Causes for its variability are not yet fully understood. There is also a lack of consensus within the scientific community about how distinct and indistinct tree rings should be defined and classified. We use a selection of 103 Central African rainforest trees to analyse the anatomy of growth-ring boundaries of 103 Central African rainforest species and assessed the influence of the climate, tree organ and leaf shedding behaviour on growth-ring distinctness and anatomy. We observed a high variability of tree-ring boundaries anatomy and distinctness within and among individuals and species. Although, for some semi-deciduous species, higher incidence of distinct growth rings appears to be related with a more pronounced seasonal climate, no general trends are observed for the assembly of studied species. Growth rings are variable within individuals depending on the considered organ: trunks tend to show more distinct rings than branches. Growth-ring distinctness is difficult to implement as a trait to measure tree performance when only based on abrupt changes in fibre size and cell wall thickness. From the potential growth-ring markers identified in the IAWA list of hardwood features, those applying to vessel and parenchyma density and distended rays appear to be more useful in tropical trees than abruptly flattened latewood fibres or abrupt changes in vessel diameter.

IAWA Journal ◽  
2008 ◽  
Vol 29 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Md. Qumruzzaman Chowdhury ◽  
Nele Schmitz ◽  
Anouk Verheydens ◽  
Ute Sass-Klaassen ◽  
Nico Koedam ◽  
...  

Nature and periodicity of growth rings were investigated in Sonneratia apetala and Heritiera fomes, two Bangladeshi mangrove species. From both species we collected three stem discs in the natural forest reserve of the Sundarbans. In addition, three discs were sampled from plantation- grown S. apetala trees of known age. Sanded stem discs revealed distinct growth rings but no periodic fluctuations in vessel variables (vessel density, vessel diameter, vessel grouping), which were measured at high resolution along a transect from pith to bark. The number of growth rings in plantation-grown S. apetala trees corresponded with the documented tree age, hence strongly suggesting the growth rings to be annual. Within species, the annual nature of the rings was further supported by a good match between the tree-ring series. The similar mean curves of S. apetala and H. fomes, growing at the same site in the Sundarbans, pointed to the presence of an external factor influencing their growth. A combination of precipitation and temperature was suggested influencing substrate salinity and phenological events. It became evident that tree-ring research in combination with the analysis of vessel patterns is a valuable tool to further investigate the complex interactions between tree growth and site ecology in mangrove forests.


IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 385-399 ◽  
Author(s):  
Valérie Trouet ◽  
Kristof Haneca ◽  
Pol Coppin ◽  
Hans Beeckman

The value of growth rings as proxy data for climate reconstruction was studied in two miombo woodland species in eastern Africa. Growth rings, marked by terminal parenchyma, were visually detectable on carefully prepared stem discs of Isoberlinia tomentosa and Brachystegia spiciformis, dominant species of the miombo woodland in north-western Tanzania. However, the presence of multiple growth ring anomalies rendered cross-dating of the growth ring series between trees difficult. Cross-dating succeeded for eight out of thirteen samples for Isoberlinia tomentosa, but was unsuccessful for Brachystegia spiciformis. A mean series of 38 years was calculated for Isoberlinia tomentosa only. Monthly precipitation, monthly maximum air temperature and monthly SOI-value (Southern Oscillation Index) correlated significantly with tree ring widths of the mean series. These correlations are strong indicators of the annual character of the growth rings. They also suggest that Isoberlinia tomentosa provides an appropriate paleoclimatic record for dendroclimatic reconstruction.


IAWA Journal ◽  
2018 ◽  
Vol 39 (4) ◽  
pp. 395-405 ◽  
Author(s):  
Cláudia Fontana ◽  
Gonzalo Pérez-de-Lis ◽  
Luiz Santini-Junior ◽  
Paulo César Botosso ◽  
Cristina Nabais ◽  
...  

ABSTRACTThe wood anatomy of Copaifera lucens Dwyer was studied with an emphasis on its growth ring boundaries. Growth rings are visible to the naked eye and demarcated by marginal parenchyma bands and, sometimes, by thick-walled fibers in the latewood. Secretory canals are associated with marginal parenchyma bands, but not all marginal parenchyma bands are associated with canals. Paratracheal parenchyma is vasicentric to lozenge-aliform. Rays are 1–4-seriate, heterocellular and non-storied. Vessels are visible to the naked eye, diffuse, predominantly solitary, some in multiples, sometimes filled with gums. Crystals present. Wood anatomical characteristics of C. lucens are in agreement with those previously reported for other species of Copaifera. In addition to what had already been described for C. lucens, we observed gelatinous fibers, and some bifurcate fibers, and extremely rare clustered vessels. The growth ring boundaries are well-defined in mature wood but less distinctive near the pith. There are also partial and confluent (wedging) rings, which are difficult to classify by anatomy only, but which represent false rings and complicate tree-ring analysis in this species.


IAWA Journal ◽  
1989 ◽  
Vol 10 (2) ◽  
pp. 155-160 ◽  
Author(s):  
R. Villalba ◽  
J. A. Boninsegna

Wood structure and seasonal variation of the cambial activity were investigated in Prosopis flexuosa DC. in order to enable the use of this species in dendrochronological and ecological studies requiring exact age determination. Cambial activity was determined by counting the number of undifferentiated cells in each radial file. Change in vessel diameter and a terminal parenchyma band, containing rhombic crystals, mark the annual growth layer. Even though the growth rings are not always clearly demarcated, one growth ring is generally formed each year. Prosopis flexuosa has an annual rhythm of wood production which coincides with the climatic rhythm. It is possible to cross-date disk samples of Prosopis species, and a first chronology has been established. Relationships between xylem production, phenology and climatic factors are discussed.


2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>


1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong

The distribution and vertical variation of juvenile wood was studied in an 81-year-old dominant tree and an 83-year-old suppressed tree of Larixlaricina (Du Roi) K. Koch. Two criteria, growth ring width and tracheid length, were used to demarcate the boundary of juvenile wood. The width of juvenile wood, expressed in centimetres and the number of growth rings, decreased noticeably from the base to the top of the tree. The volume of juvenile wood decreased in a similar pattern. These decreasing trends had a strong negative correlation with the year of formation of cambial initials at a given tree level. The length of these cambial initials decreased with increasing age of formation of the cambial initials. In the juvenile wood zone, there was a positive linear regression between the growth ring number (age) and the tracheid length. The slopes of these regression lines at various tree levels increased as the age of the year of formation of the cambial initials increased. At a given tree level, the length of tracheids increased from the pith to a more uniform length near the bark. However, the number of years needed to attain a more uniform tracheid length decreased from the base to the top of the tree. These relationships suggest that the formation of juvenile wood is related to the year of formation of the cambial initials. Consequently, the juvenile wood is conical in shape, tapering towards the tree top.


2011 ◽  
Vol 301 (1) ◽  
pp. H48-H60 ◽  
Author(s):  
Michael J. Davis ◽  
Elaheh Rahbar ◽  
Anatoliy A. Gashev ◽  
David C. Zawieja ◽  
James E. Moore

Secondary lymphatic valves are essential for minimizing backflow of lymph and are presumed to gate passively according to the instantaneous trans-valve pressure gradient. We hypothesized that valve gating is also modulated by vessel distention, which could alter leaflet stiffness and coaptation. To test this hypothesis, we devised protocols to measure the small pressure gradients required to open or close lymphatic valves and determine if the gradients varied as a function of vessel diameter. Lymphatic vessels were isolated from rat mesentery, cannulated, and pressurized using a servo-control system. Detection of valve leaflet position simultaneously with diameter and intraluminal pressure changes in two-valve segments revealed the detailed temporal relationships between these parameters during the lymphatic contraction cycle. The timing of valve movements was similar to that of cardiac valves, but only when lymphatic vessel afterload was elevated. The pressure gradients required to open or close a valve were determined in one-valve segments during slow, ramp-wise pressure elevation, either from the input or output side of the valve. Tests were conducted over a wide range of baseline pressures (and thus diameters) in passive vessels as well as in vessels with two levels of imposed tone. Surprisingly, the pressure gradient required for valve closure varied >20-fold (0.1–2.2 cmH2O) as a passive vessel progressively distended. Similarly, the pressure gradient required for valve opening varied sixfold with vessel distention. Finally, our functional evidence supports the concept that lymphatic muscle tone exerts an indirect effect on valve gating.


2014 ◽  
Vol 10 (2) ◽  
pp. 437-449 ◽  
Author(s):  
P. Breitenmoser ◽  
S. Brönnimann ◽  
D. Frank

Abstract. We investigate relationships between climate and tree-ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of tree-ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found during the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 °C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level tree-ring series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the tree-ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model's ability to skilfully capture the climatic signal contained in tree-ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.


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