Growth ring formation of Dichrostachys cinerea and Senegalia mellifera in arid environments in Namibia

2020 ◽  
Vol 59 ◽  
pp. 125661
Author(s):  
R. Shikangalah ◽  
B. Mapani ◽  
I. Mapaure ◽  
U. Herzschuh ◽  
A. Musimba ◽  
...  
Keyword(s):  
Growth Ring ◽  
Ring Formation ◽  
Arid Environments ◽  
Dichrostachys Cinerea

scholarly journals Cambial Activity of Moringa peregrina (Forssk.) Fiori in Arid Environments

2021 ◽  
Vol 12 ◽  
Author(s):  
Holger Gärtner ◽  
Emad Farahat
Keyword(s):  
Photosynthetic Activity ◽  
Storage Capacity ◽  
Cambial Activity ◽  
Ring Formation ◽  
Arid Environments ◽  
Dry Tropics ◽  
Xylem Formation ◽  
Moringa Peregrina ◽  
Desert Regions ◽  
Environmental Adaptability

Moringa peregrina (Forssk.) Fiori, one of 13 species of the Moringaceae family widely distributed throughout the dry tropics, has the potential to become one of the most economically important medicinal plants in Egypt. However, despite its tolerance for drought and heat, it is also threatened by increasing temperatures and decreasing precipitation. Although the phenophase of this species is well documented, almost nothing is known about its period of cambial activity in desert regions. Ring formation and the general environmental adaptability of trees are affected by the timing of cambial activation. In our study site, we observe a distinct coupling of the development of new green leaves at the onset of vegetative growth in October and the phase of cambial activity (November–January). The onset of cambial activity seems to be related to a drop in temperature in October and the onset of torrential rains in the region. There might even be a short phase between the end of cambial activity and the onset of bud formation without xylem formation, but with photosynthetic activity. If so, we assume that all assimilates are stored as non-structural carbohydrates (NSC) in the parenchyma of the new ring. This potential gap opens new questions regarding the correlation between NSC storage capacity and the timing of remobilization for subsequent ring formation.

Using growth ring formation to study growth patterns of exploited sea urchin (Loxechinus albus) populations

2018 ◽  
Vol 201 ◽  
pp. 88-97 ◽  
Author(s):  
Cecilia Balboa ◽  
Carlos Molinet ◽  
Nancy Barahona ◽  
Patricio A. Díaz ◽  
Dagoberto Subiabre ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Growth Ring ◽  
Growth Patterns ◽  
Ring Formation ◽  
Loxechinus Albus

scholarly journals Growth Ring Formation in the Starch Granules of Potato Tubers

2003 ◽  
Vol 132 (1) ◽  
pp. 365-371 ◽  
Author(s):  
Emma Pilling ◽  
Alison M. Smith
Keyword(s):  
Growth Ring ◽  
Ring Formation ◽  
Starch Granules ◽  
Potato Tubers

Growth Rings in Agathis robusta and Araucaria cunninghamii From Tropical Australia

1983 ◽  
Vol 31 (3) ◽  
pp. 269 ◽  
Author(s):  
J Ash
Keyword(s):  
Growth Rates ◽  
Growth Ring ◽  
Tropical Climate ◽  
Ring Formation ◽  
Vascular Cambium ◽  
Growth Rings ◽  
Radiocarbon Dates ◽  
Tropical Australia ◽  
Araucaria Cunninghamii ◽  
Slow Growing

Agathis robusta and Araucaria cunninghamii trees growing in a seasonal tropical climate in north Queensland produce late wood during cooler and drier periods. Vascular cambium growth rates fluctuate, and slow-growing trees may temporarily have inactive cambium around parts of the trunk so no growth ring is formed. Radiocarbon dates on old Agathis trees indicate that the frequency of ring formation is less than annual.

Impact of various soil hydraulic properties and water source-sink relations on plant rings formation and sizes under arid conditions

2020 ◽  
Author(s):  
Ofir Katz ◽  
Yair Herooty ◽  
Pua Bar (Kutiel) ◽  
Hezi Yizhaq
Keyword(s):  
Water Supply ◽  
Hydraulic Properties ◽  
Sandy Soils ◽  
Water Source ◽  
Ring Formation ◽  
Arid Environments ◽  
Soil Hydraulic Properties ◽  
Local Soil ◽  
Soil Hydraulic ◽  
Source Sink

<p>In semi-arid and arid environments, clonal plants occasionally appear in ring patterns with a barren soil centre. There is a general agreement that this pattern forms when ramets grow radially, leaving a dead centre where the parent plant once was. Nevertheless, there is still some controversy over the nature of water source-sink relations in and around the rings, and the mechanism that drive the ring formation. We studied Asphodelus ramosus rings in two sites with different soil types (sand and loess) but comparable climate, in order to understand whether differences in soil hydraulic properties create different water source-sink relations and mechanisms that drive ring formation. We characterised soil hydraulic properties and dynamics along the rainy season and during the dry season, accompanied by measurements of soil texture and of belowground storage root biomass. We found that the nature of source-sink relations varies with soil type and properties. In sandy soils, water supply to ring perimeters is mainly from their centre. In loessial soils, water supply to ring perimeters is mainly from the surrounding matrix. Consequently, rings are larger in sandy soils than in loessial soils, in each case in order to optimise water source area. Therefore, studying the formation of rings and other vegetation spatial patterns should consider local soil properties and the possibility that similar patterns may emerge through various mechanisms.</p>

Exploring the 14C Bomb Peak with Tree Rings of Tropical Species from the Amazon Forest

Radiocarbon ◽  
2017 ◽  
Vol 59 (2) ◽  
pp. 303-313 ◽  
Author(s):  
R Linares ◽  
H C Santos ◽  
A F N Brandes ◽  
C F Barros ◽  
C S Lisi ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Tree Rings ◽  
Wood Anatomy ◽  
Growth Ring ◽  
Ring Formation ◽  
Tropical Species ◽  
Amazon Forest ◽  
Good Match ◽  
Individual Tree ◽  
Northern Brazil

AbstractIn this work we explore the radiocarbon (14C) signal as an independent tool to assess the year of formation of individual tree rings of tropical species in northern Brazil. Three different species were analyzed in this work: Dipteryx magnifica, Enterolobium maximum, and Hymenolobium petraeum. The studied samples are from the stem of only one individual of each species, all cut down in 2008 in Porto Trombetas, Pará, Brazil. Individual tree rings were identified based on wood anatomy and they were counted from bark to pith. Several rings were selected for 14C analysis in order to cover the overall shape of the 14C atmospheric bomb peak (after 1955). The 14C content was measured at Laboratory of Radiocarbon, Universidade Federal Fluminense (LAC-UFF). Results are compared with the Southern Hemisphere 14C atmospheric calibration curves. For E. maximum and H. petraeum the 14C signal exhibits an overall good match with the SH zone 3 and suggests annual seasonality in the growth-ring formation. These species offer suitable characteristics for dendrochronology. The D. magnifica shows mismatches in the 14C measurements that are likely a result of difficulties in identifying ring boundaries with certainty. Additional techniques may be helpful to disentangle the origin of this discrepancy.

Some Wood Anatomical, Physiological, and Silvicultural Aspects of Silver Fir Dieback in Slovenia (NW Yugoslavia)

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 343-350 ◽  
Author(s):  
N. Torelli ◽  
K. Čufar ◽  
D. Robič
Keyword(s):  
Growth Ring ◽  
Physiological Mechanism ◽  
Basal Area ◽  
Growth Suppression ◽  
Ring Formation ◽  
Basal Area Increment ◽  
Silver Fir ◽  
Height Increment ◽  
Dry Zone ◽  
Heart Formation

Silver fir dieback in Slovenia (NW Yugoslavia) was evaluated, and growth suppression and some physiological and anatomical aspects of growth ring formation were studied. The drastic growth suppression after 1950 was reflected in poor basal area increment, and by discontinuous as weil as missing rings. Only in the most diseased trees the height increment was affected. Generally latewood percentage and tracheid dimensions remained unchanged. The physiological mechanism of wetwood formation in sapwood of fir is discussed and compared with red heart formation in beech. On the basis of preliminary experiments, osmotic transport is suggcsted from sapwood to heartwood through the intermediate dry zone.

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