Variations in pith eccentricity and ring width in teak (Tectona grandis L. F.)

Trees ◽  
1989 ◽  
Vol 3 (2) ◽  
pp. 111-116 ◽  
Author(s):  
A. E. Akachuku ◽  
D. A. O. Abolarin
Keyword(s):  
Ring Width ◽  
Tectona Grandis ◽  
Pith Eccentricity

Variations in pith eccentricity and ring width in teak (Tectona grandis L. F.)

Trees ◽  
1989 ◽  
Vol 3 (2) ◽  
Author(s):  
A.E. Akachuku ◽  
D.A.O. Abolarin
Keyword(s):  
Ring Width ◽  
Tectona Grandis ◽  
Pith Eccentricity

scholarly journals Growth rate and ring width variability of teak, Tectona grandis (Verbenaceae) in an unmanaged forest in East Timor.

2012 ◽  
Vol 60 (1) ◽  
Author(s):  
Vicelina B. Sousa ◽  
Sofia Cardoso ◽  
Teresa Quilhó ◽  
Helena Pereira
Keyword(s):  
Growth Rate ◽  
Ring Width ◽  
Tectona Grandis ◽  
East Timor ◽  
Unmanaged Forest

El Niño and related monsoon drought signals in 523-year-long ring width records of teak (Tectona grandis L.F.) trees from south India

2010 ◽  
Vol 285 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
H.P. Borgaonkar ◽  
A.B. Sikder ◽  
Somaru Ram ◽  
G.B. Pant
Keyword(s):  
El Niño ◽  
South India ◽  
El Nino ◽  
Ring Width ◽  
Tectona Grandis ◽  
Tectona Grandis L.F

scholarly journals Teak Tree-Ring Cellulose δ13C, δ18O, and Tree-Ring Width from Northwestern Thailand Capture Different Aspects of Asian Monsoon Variability

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 778
Author(s):  
Nathsuda Pumijumnong ◽  
Paramate Payomrat ◽  
Supaporn Buajan ◽  
Achim Bräunig ◽  
Chotika Muangsong ◽  
...  
Keyword(s):  
Tree Ring ◽  
Rainy Season ◽  
Asian Monsoon ◽  
Hydrological Cycle ◽  
Ring Width ◽  
Tectona Grandis ◽  
Strong Relationship ◽  
Tree Ring Chronology ◽  
Northwestern Thailand ◽  
Tree Ring Cellulose

The inter-annual variability in tree-ring cellulose δ13C (δ13CTR, δ18OTR), and tree-ring chronology in teak (TRW) (Tectona grandis L.f.) trees from Northwestern Thailand during 1901–2009 AD was performed. The δ13CTR and δ18OTR have a positive correlation, significant at r = 0.400, p < 0.0001, and both of the stable isotopes were not significantly related to the TRW. The TRW is related to rainfall in the first half of the rainy season and has a strong relationship with the relative humidity. The δ18OTR captured moisture well throughout the rainy season, and the δ13CTR had a strong correlation with rainfall in the second half of the rainy season and had a high correlation with cloud fraction and vapor pressure. The δ13CTR and δ18OTR were associated with the stomata conductance response, but had no effect on photosynthesis. The three indices of the teak annual ring respond well to the variability in the Asian monsoon, and give us a better understanding of both the hydrological cycle and the factors that contribute to the growing of tropical broadleaf trees under changing climates.

scholarly journals Variation in Climate Signals in Teak Tree-Ring Chronologies in Two Different Growth Areas

Forests ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 772 ◽  
Author(s):  
Sineenart Preechamart ◽  
Nathsuda Pumijumnong ◽  
Paramate Payomrat ◽  
Supaporn Buajan
Keyword(s):  
Tree Ring ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Ring Width ◽  
Tectona Grandis ◽  
Ring Structure ◽  
Limiting Factor ◽  
Tree Ring Chronology ◽  
Teak Tree ◽  
Northwestern Thailand

We developed two tree-ring chronologies of teak (Tectona grandis L.f.) from Mae Tuen (462-year, 1555–2016) and Umphang (165-year, 1852–2016) in Tak province, northwestern Thailand. The chronologies were based on 67 and 71 living teak trees, respectively. We used crossdating methods to check and verify the tree-ring width data and tree-ring chronology construction using the ARSTAN program. In this study, the two teak tree-ring chronologies from two different growth areas could not be crossdated. The relationship among these chronologies is, thus, relatively low (r = 0.33, n = 165, p < 0.01). This result shows that the growth of tree-ring structure from two sites can be affected by a variety of non-climatic patterns due to site variation, such as topography, nutrient, light, and internal factors. However, these chronologies have a significant positive correlation with rainfall, during the pre-monsoon season (April to May). As demonstrated by the spatial correlation patterns, these chronologies represent April to May rainfall, which was a limiting factor of teak growth from northwestern Thailand. While the difference in surface temperatures of the Indian Ocean Dipole (IOD) might not be affected by rainfall, its unstable relationship with the El Niño-Southern Oscillation (ENSO) was noted to have occurred.

Influence of anatomy on the adhesion performance of four wood species

2020 ◽  
Vol 9 (4) ◽  
pp. e31942727
Author(s):  
João Gabriel Missia da Silva ◽  
Pedro Nicó de Medeiros ◽  
Denise Ransolin Soranso ◽  
Vinicius Peixoto Tinti ◽  
José Tarcísio da Silva Oliveira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Specific Gravity ◽  
Wood Species ◽  
Tectona Grandis ◽  
Glue Line ◽  
Anatomical Characteristics ◽  
Ray Cells ◽  
Adhesion Performance ◽  
Adhesion Process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

Fuel Characterization of Bio-oil from Fast Pyrolysis of Tectona grandis in a Fixed Bed Reactor

2020 ◽  
Author(s):  
Pious Okekunle ◽  
Akinola Ogunsola ◽  
Oluwapelumi Babayemi ◽  
Emmanuel Abodunrin ◽  
Olanrewaju Daramola
Keyword(s):  
Fast Pyrolysis ◽  
Fixed Bed ◽  
Tectona Grandis ◽  
Fixed Bed Reactor ◽  
Bio Oil ◽  
Fuel Characterization

In-vivo anti-oxidant screening of Tectona grandis extract

2020 ◽  
Vol 9 (1) ◽  
pp. 1-4
Author(s):  
Tamilarasi G P ◽  
Sabarees G
Keyword(s):  
Biochemical Parameters ◽  
Tectona Grandis ◽  
The Body ◽  
Altered Expression ◽  
Physiological Conditions ◽  
Synthetic Drugs ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Radical Generation

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.

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