scholarly journals Age and Growth Rate Dynamics of an Old African Baobab Determined by Radiocarbon Dating

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 727-734 ◽  
Author(s):  
Adrian Patrut ◽  
Diana H Mayne ◽  
Karl F von Reden ◽  
Daniel A Lowy ◽  
Sarah Venter ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Growth Rate ◽  
Radiocarbon Dating ◽  
Age And Growth ◽  
Sectional Area ◽  
Adansonia Digitata ◽  
Cross Sectional ◽  
Volume Increase ◽  
The Past ◽  
Area Increase

In 2008, a large African baobab (Adansonia digitata L.) from Makulu Makete, South Africa, split vertically into 2 sections, revealing a large enclosed cavity. Several wood samples collected from the cavity were processed and radiocarbon dated by accelerator mass spectrometry (AMS) for determining the age and growth rate dynamics of the tree. The 14C date of the oldest sample was found to be of 1016 ± 22 BP, which corresponds to a calibrated age of 1000 ± 15 yr. Thus, the Makulu Makete tree, which eventually collapsed to the ground and died, becomes the second oldest African baobab dated accurately to at least 1000 yr. The conventional growth rate of the trunk, estimated by the radial increase, declined gradually over its life cycle. However, the growth rate expressed more adequately by the cross-sectional area increase and by the volume increase accelerated up to the age of 650 yr and remained almost constant over the past 450 yr.

Influence of tree age and growth rate on the radial resin duct system in loblolly pine (Pinus taeda)

1986 ◽  
Vol 64 (5) ◽  
pp. 1046-1049 ◽  
Author(s):  
J. D. DeAngelis ◽  
T. E. Nebeker ◽  
J. D. Hodges
Keyword(s):  
Growth Rate ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Dendroctonus Frontalis ◽  
Age And Growth ◽  
Tree Age ◽  
Secretory Cells ◽  
Tangential Plane ◽  
Cross Sectional ◽  
Resin Duct

Formation of radial resin ducts and their associated secretory cells in loblolly pine (Pinus taeda L.) is influenced by the age and growth rate of the annual ring in which the ducts are formed. The spatial pattern of radial ducts on the tangential plane is nonrandom, exhibiting a regular or dispersed pattern. A significantly higher density of radial ducts was found in the inner, first-formed growth rings at all heights within the tree. Radial duct formation was found to be positively correlated with radial growth rate, when growth rate is expressed as increment of cross-sectional area growth. These findings may partially explain why older, slower growing trees tend to be more susceptible to attack by the southern pine beetle, Dendroctonus frontalis Zimmermann, and associated microorganisms, since the resin-producing system is a primary defense against these agents.

scholarly journals Influence of Irrigation Regime on Water Relations, Gas Exchange, and Growth of Two Field-grown Redbud Varieties in a Semiarid Climate

2014 ◽  
Vol 32 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Lindsey Fox ◽  
Amber Bates ◽  
Thayne Montague
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Leaf Area ◽  
Shoot Elongation ◽  
Sectional Area ◽  
Irrigation Regime ◽  
Cross Sectional ◽  
Area Increase ◽  
Irrigation Volume

For three growing seasons (2003–2005) two newly planted, field-grown redbud (Cercis canadensis L.) varieties were subjected to three reference evapotranspiration (ETo)-based irrigation regimes (100, 66, and 33% ETo). Over this time period, water relations (pre-dawn leaf water potential), gas exchange (mid-day stomatal conductance), and growth data (trunk cross sectional area increase, tree leaf area, and shoot elongation) were measured. Pre-dawn leaf water potential (ψl) was more negative for trees receiving the least amount of irrigation, and for Mexican redbud [C. canadensis var. mexicana (Rose) M. Hopkins] trees. However, mid-day stomatal conductance (gs) was similar for Texas redbud (C. canadensis var. texensis S. Watson) trees across the three irrigation regimes, and was highest for Mexican redbud trees receiving the greatest amount of irrigation volume. Growth varied by variety and irrigation regime. Trunk cross sectional area increase was greatest for Mexican redbud trees, leaf area was highest for trees receiving the greatest amount of irrigation, and shoot elongation was greatest for trees receiving the 66% ETo irrigation regime. However, despite differing irrigation volumes, greatest gas exchange and growth was not necessarily associated with greatest irrigation volume. When considering conservation of precious water resources, these redbud varieties maintain adequate growth and appearance under reduced irrigation.

scholarly journals Age, Growth and Death of a National Icon: The Historic Chapman Baobab of Botswana

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 983 ◽  
Author(s):  
Adrian Patrut ◽  
Stephan Woodborne ◽  
Roxana T. Patrut ◽  
Grant Hall ◽  
Laszlo Rakosy ◽  
...  
Keyword(s):  
Growth Rate ◽  
Radiocarbon Dating ◽  
Radiocarbon Date ◽  
Rate Variation ◽  
The Past ◽  
Open Ring ◽  
Climate Evolution ◽  
National Icon ◽  
Ring Shaped Structure ◽  
Past 1000 Years

The year 2016 witnessed the fall of a symbol of the botanical world: the historic Chapman baobab of Botswana. This article presents the results of our investigation of the standing and fallen tree. The Chapman baobab had an open ring-shaped structure composed of six partially fused stems. Several wood samples collected from the stems prior and after their collapse were analysed by using radiocarbon dating. The radiocarbon date of the oldest sample was 1381 ± 22 BP, which corresponds to a calibrated age of 1345 (+10, −15) calendar years. The dating results show that the six stems of the Chapman baobab belonged to three different generations, which were 1350–1400, 800–1000 and 500–600 years old. The growth rate variation of the largest and oldest stem is presented and correlated with the climate evolution in the area over the past 1000 years. The factors that determined the sudden fall and death of the Chapman baobab are also presented and discussed.

scholarly journals Fire History of a Giant African Baobab Evinced by Radiocarbon Dating

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 717-726 ◽  
Author(s):  
Adrian Patrut ◽  
Diana H Mayne ◽  
Karl F von Reden ◽  
Daniel A Lowy ◽  
Robert van Pelt ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
South Africa ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Fire History ◽  
Adansonia Digitata ◽  
Entire Area ◽  
History Of

The article reports the first radiocarbon dating of a live African baobab (Adansonia digitata L.), by investigating wood samples collected from 2 inner cavities of the very large 2-stemmed Platland tree of South Africa. Some 16 segments extracted from determined positions of the samples, which correspond to a depth of up to 15–20 cm in the wood, were processed and analyzed by accelerator mass spectrometry (AMS). Calibrated ages of segments are not correlated with their positions in the stems of the tree. Dating results indicate that the segments originate from new growth layers, with a thickness of several centimeters, which cover the original old wood. Four new growth layers were dated before the reference year AD 1950 and 2 layers were dated post-AD 1950, in the post-bomb period. Formation of these layers was triggered by major damage inside the cavities. Fire episodes are the only possible explanation for such successive major wounds over large areas or over the entire area of the inner cavities of the Platland tree, able to trigger regrowth.

Ductile Fracture of Rapidly Expanding Rings

1983 ◽  
Vol 50 (3) ◽  
pp. 593-600 ◽  
Author(s):  
J. N. Johnson
Keyword(s):  
Growth Rate ◽  
Plastic Deformation ◽  
Differential Equations ◽  
Spatial Dimension ◽  
Momentum Conservation ◽  
Thermal Softening ◽  
Sectional Area ◽  
Cross Sectional ◽  
Rate Dependent ◽  
Work Hardening Rate

Heterogeneous plastic deformation (necking) of thin ductile rings given an initial outward impulse is described in terms of the ordinary differential equations of thermoplasticity and the partial differential equations of mass and momentum conservation in one spatial dimension (circumference) and time. Flaws in cross-sectional area and porosity are introduced and the resulting plastic deformation is calculated numerically for a prescribed initial radial velocity. Plastic deformation is initially homogeneous but soon concentrates in the weakest region, which then thins rapidly and fractures. Effects of flaw wavelength, work-hardening rate, thermal softening, and rate-dependent plastic flow on the flaw growth rate are studied.

Measurement of Age and Growth Rate in the Crustose Saxicolous Lichen Caloplaca Trachyphylla Using 14C Accelerator Mass Spectrometry

2000 ◽  
Vol 32 (4) ◽  
pp. 399-403 ◽  
Author(s):  
B. M. Clark ◽  
N. F. Mangelson ◽  
L. L. St. Clair ◽  
L. B. Rees ◽  
G. S. Bench ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Growth Rate ◽  
Growth Curve ◽  
Linear Dependence ◽  
Growth Rates ◽  
Accelerator Mass Spectrometry ◽  
Radial Growth ◽  
Age And Growth ◽  
Radial Position ◽  
Radial Growth Rate

AbstractSections of the crustose saxicolous lichen, Caloplaca trachyphylla, were dated using 14C accelerator mass spectrometry (AMS). The data show a stron linear dependence of radial position on time (r=0.993), suggesting a constant radial growth rate. This specimen had averaged a marginal growth rate of 1.48 mm/year. Extrapolation of the growth curve yields a thallus age of 20 years. These data demonstrate the feasibility of using AMS technology to precisely date lichen tissues and determine growth rates of lichen thalli.

scholarly journals 503 Effect of Source and Timing of Potassium Fertilizer on `Empire' Apple Tree Growth, Yield, and Fruit Quality

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 481C-481
Author(s):  
Terence L. Robinson ◽  
Warren Stiles
Keyword(s):  
Tree Growth ◽  
Fruit Size ◽  
Growth Yield ◽  
Sectional Area ◽  
Potassium Fertilizer ◽  
Trickle Irrigation ◽  
Cross Sectional ◽  
Early Season ◽  
Red Color ◽  
Area Increase

A field experiment was established in 1993 in a 3-year-old `Empire'/M.9 apple orchard. An incomplete factorial treatment design compared nitrogen only fertilization with nitrogen plus potassium fertilizer applied either on the ground with and without trickle irrigation or through the trickle irrigation system. Timing of potassium fertigation treatments compared season-long K fertigation to early season or late-season K fertigation. Results of main effects showed that K fertilization reduced trunk cross-sectional area increase, but increased yield, fruit size, and fruit red color. There was no benefit of fertigation compared to ground application of fertilizers plus trickle irrigation. There was no effect of source of K fertilizer (KCl vs KNO3) on tree growth, yield, fruit size, or color. Time of K fertigation showed that late-season K fertigation resulted in greater trunk cross-sectional area increase compared to early season fertigation or season-long fertigation. Fruit size was greatest when K fertigation was done in the early season. There was no effect of time of fertigation on yield or fruit red color. Potassium fertilization increased leaf K levels and reduced leaf Mg levels. Time of fertigation did not affect leaf K levels, but early season fertigation resulted in higher leaf N levels.

scholarly journals Carambola Growth and Leaf Gas-exchange Responses to Seismic or Wind Stress

HortScience ◽  
1992 ◽  
Vol 27 (8) ◽  
pp. 913-915 ◽  
Author(s):  
Thomas E. Marler ◽  
Yasmina Zozor
Keyword(s):  
Growth Rate ◽  
Gas Exchange ◽  
Leaf Area ◽  
Leaf Gas Exchange ◽  
Dry Weight ◽  
Area Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
Relative Growth ◽  
Seismic Stress

Growth and leaf gas-exchange responses of carambola (Averrhoa carambola L.) seedlings to wind or seismic stress were studied under glasshouse conditions. Forty days of twice daily seismic stress applied for 10 seconds consistently reduced carambola height, leaf area, dry weight, relative growth rate, and leaf-area ratio, but increased trunk cross-sectional area compared with plants receiving no seismic stress. Fifty-one days of wind load reduced plant height, leaf area, dry weight, trunk cross-sectional area, net assimilation rate, relative growth rate, leaf-area ratio, and stomatal conductance compared with plants receiving no wind stress. Morphological appearance was similar for plants receiving wind or seismic stress. Net CO2 assimilation of carambola leaflets was reduced by 30 minutes of wind load for up to 6 hours following the stress. Results suggest that wind may reduce carambola growth at least partially by influencing leaf gas exchange or by the mechanical stress associated with wind.

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