Calcium Oxalate Crystals in African Acacia Species and Them Analysis by Scanning Proton Microprobe (Spm)

IAWA Journal ◽  
1994 ◽  
Vol 15 (2) ◽  
pp. 137-148 ◽  
Author(s):  
I.D. Gourlay ◽  
G.W. Grime

The radial and cross sections of wood samples from individual trees of known age of African Acacia species were examined for growth rings. These were apparent in most species as narrow bands of marginal parenchyma filled with long crystal chains. The crystals were subsequently identified as calcium oxalate through the use of a scanning proton microprobe. Several other chemical elements were concentrated around this zone. The number of parenchyma bands formed annually corresponded to the number of peaks in the annual rainfall distribution. These results suggest that the presence of marginal parenchyma bands and crystalliferous chains define growth phases in African Acacia species, and can be used for age determination.

IAWA Journal ◽  
1991 ◽  
Vol 12 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Ian D. Gourlay ◽  
Peter J. Kanowski

The radial cross sections of wood samples from individuals of known age in six African Acacia species were examined for growth rings, which were apparent in most species as narrow bands of marginal parenchyma filled with long crystal chains. The number of bands formed annually corresponded to the number of peaks in rainfall distribution. Samples from specimens of African Acacia species from the Oxford Forestry Institute's xylarium (FHOw) were also examined for similar crystalliferous chains, which were generally present. These results suggest that marginal parenchyma bands and crystalliferous chains define growth phases in African Acacia species, and may therefore be useful for age determination.


1995 ◽  
Vol 11 (1) ◽  
pp. 121-140 ◽  
Author(s):  
Ian D. Gourlay

ABSTRACTThe age of most temperate tree species can be estimated accurately by counting the annual rings revealed by concentric changes in their wood anatomy. In the tropics and sub-tropics, this growth periodicity is seldom clearly and unambiguously defined. This research investigates whether a wood anatomical feature is present that delimits annual periods in one of the most widely distributed genera in the semi-arid and arid areas of Africa, Acacia.Most research on this topic has been based on sample trees from natural stands, often the largest and putatively oldest trees. In contrast, the trees sampled for this study were actively sought from material of known age, particularly those for which the history of management was known. Several African Acacia species were examined for growth rings. These were apparent in most species as narrow bands of marginal parenchyma filled with long crystal chains. The crystals were sub-sequendy identified as calcium oxalate through the use of a scanning proton microprobe. The number of bands formed annually corresponded to the number of peaks in the annual rainfall distribution. Ring widths were highly correlated with total annual rainfall.


2014 ◽  
Vol 80 (6) ◽  
pp. 917-927 ◽  
Author(s):  
TOSHIAKI OHMURA ◽  
HIDEKI TAKAMI ◽  
TOYOMITSU HORII ◽  
TADAKATSU NORO ◽  
KEN HORIKOSHI ◽  
...  

IAWA Journal ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 359-379 ◽  
Author(s):  
Fritz Hans Schweingruber

Cross sections of 760 trunks of approximately 670 species from 47 families of shrubs, dwarf shrubs, and trees were examined to study the incidence and appearance of different categories of growth zones. In montane/alpine sites with relatively cool winter temperatures all the woody plants form distinct growth rings similar to those seen in boreal and temperate regions throughout the world, and thus these rings are considered to represent annual rings. Most species from this phytogeographical zone are useful for crossdating. In the savannahs, the jarrah and karri woodlands of the southwest and the subtropical rain forests of the southeast identifiable growth zones are formed in most species. The approximate age of the woods can be determined, but crossdating is difficult or impossible. In the desert areas woody plants form irregular growth zones, the number of which may correspond to the incidence of rainfall, and age determination and crossdating is mostly impossible. Members of the well-studied families Cupressaceae, Epacridaceae and Myrtaceae form growth zones that are more distinct than the Mimosaceae and Proteaceae. Included phloem is present in all Chenopodiaceae, one Loranthaceae and two species of Verbenaceae.


1985 ◽  
Vol 1 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Soedarsono Riswan ◽  
J. B. Kenworthy ◽  
Kuswata Kartawinata

ABSTRACTIn the absence of growth rings it is difficult to give a precise time scale for processes associated with the re-establishment of tropical rain forest. This paper explores other methods by which a time scale may be constructed. The proportions of primary and secondary species, an index of similarity, biomass measurements, girth dimensions and gap size are all considered from sites in East Kalimantan, Indonesia. Data from primary, secondary and experimentally cleared forest sites are compared to estimate the minimum time required for various phases involved in the re-establishment of tropical rain forest after disturbance. A simple model is proposed to accommodate the data and other estimates in the literature. The model predicts a minimum period for the stablization of secondary species numbers as 60–70 years and the replacement of primary species as 150 years at which point gap formation is initiated. After approximately 220–250 years biomass stabilizes while individual trees exist for over 500 years.


2019 ◽  
Vol 5 (9) ◽  
pp. 1877-1892 ◽  
Author(s):  
Majed Rodhan Hussain ◽  
Basim Sh. Abed

The alluvial fan of Mandali located between latitude 30˚45’00” N longitude 45˚30’00” E in east of Diyala Governorate, Iraq. Thirty-five wells were identified in the study area with average depth of 84 m and estimated area of 21550 ha. A three-dimensional conceptual model was prepared by using GMS program. From wells cross sections, four geological layers have been identified. The hydraulic conductivity of these layers was calculated for steady state condition, where the water levels for nine wells distributed over the study area were observed at same time. Afterward, PEST facility in the GMS was used to estimate the aquifer hydraulic characteristics. Other characteristics such as storage coefficient and specific yield have been determined from one year field observations that were collected by General Authority of Groundwater, Diyala Governorate. Also, the observations were used for calibration of unsteady state model. Then wells were hypothetically redistributed and increased to 103 wells, assuming a distance of 1500 m between the wells, a well productivity rate of were 7 l/s, annual rainfall rate was used for recharging. Three different wells operating times were suggested and these 6, 12, and 18 hr/day with total discharge of 150, 300, 450 m3/day and maximum drawdown of 7, 11, and 20 m respectively. For water quality assessment, the collected groundwater samples were analysed at the laboratory.  Results showed that the TDS in all wells was ranged from 1000-3000 mg/l but TDS in well number 18 was exceeded 3000 mg/l which indicate that the groundwater in this well is not recommended to be used for irrigation. According to Iraqi standard for drink (IQS 2009), it can be used for drinking if saline treatment units were provided.


2019 ◽  
Vol 23 ◽  
pp. 1
Author(s):  
F. Käppeler

The abundances of the chemical elements heavier than iron can be attributed in about equal parts to the r and s processes, which are taking place in supernova explosions and during the He and C burning phases of stellar evolution, respectively. So far, quantitative studies of the r-process are out of reach, because it involves reactions on extremely short-lived neutron-rich nuclei. On the contrary, the situation for the s-process is far advanced, thanks to a comprehensive database of experimental (n,γ) cross sections for most isotopes along the reaction path from 12C to the Pb/Bi region. For the stable isotopes last gaps in the data are presently closed, but further studies are clearly needed to reach the required accuracy and to resolve remaining discrepancies. The quest for cross sections of unstable isotopes remains a persisting challenge though. In particular, nuclei which act as branching points are of prime interest, because they provide key information on the deep stellar interior. While the activation method is limited to a few exceptional branch-point nuclei, successful measurements via the time-of- flight technique are depending on intense pulsed neutron sources and elaborate methods for sample production. Current developments in Europe are providing promising perspectives in both areas.


2021 ◽  
Vol 16 (3) ◽  
pp. 755-763
Author(s):  
M. Nagaraj M. Nagaraj ◽  
M. Udayakumar

A forest tree inventory study was conducted in Vallanadu Black buck sanctuary, Tuticorin. The current study was conducted to assess tree density, species richness, basal area (BA) and aboveground biomass (AGB) stockpile. The study area has been classified as Southern Thorn Forest (SFT). One hundred square plots (total area 1 ha), each 10m × 10m (100 m2 each) laid randomly across study area. All live trees with ≥5 cm diameter at breast height (DBH) measured at 137 cm above the ground. As the whole, 1335 individual trees ≥5cm DBH recorded. A total number of 18 species recorded from 14 genera and 11 families in study area. The family Mimosaceae has maximum number of species (7 species) followed by Rhamnaceae (2 species), while 9 families had just single species’ each. The total basal area recorded was 22.046 m2 ha-1, while, the mean wood density (WD) of trees estimated as 0.70±0.093 g cm-3. Total amount of 50.065 Mg ha-1 present in STF. The contribution of different species in terms of total AGB varied significantly. Commiphora berryi stocked 45.13% (22.588 Mg ha-1) of AGB followed by A. planifrons (23.31%, 11.669 Mg ha-1), A. mellifera (7.233%, 3.621 Mg ha-1), whereas remaining 15 species collectively stocked 24.327% (12.187 Mg ha-1) AGB. The STF had a large number of trees compared to some dry forests within Tamil Nadu. Southern Thorn Forest endowed with a moderate number of trees species. Aboveground biomass stockpile of trees is comparable with the range recorded from Indian dry forests. The study area experiences lesser mean annual rainfall and >6 months dry season. Further, endowed with short-bole and smaller leaved trees, hence stocked a relatively lesser AGB in trees.


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