annual rings

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Related to annual rings: Medullary rays

annual rings

a series of concentric circles found in the heartwood of trees, indicating the approximate age of the tree. Each ring is formed by the contrast in texture between spring wood and autumn wood. Spring wood in ANGIOSPERMS contains a high proportion of large, thin-walled XYLEM vessels and few fibres, for maximum water transport when the leaves are newly formed. Autumn wood contains fewer, smaller, thicker-walled vessels with many fibres for greater mechanical support. GYMNOSPERMS show similar contrasting structures in spring wood and autumn wood, although their water-conducting tissues contain TRACHEIDS, not vessels. Microscopic examination of annual rings (a science called DENDROCHRONOLOGY) has revealed many interesting facts about past climates and also allows wooden structures (e.g. building timbers) to be accurately dated.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

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dendrochronology

References in periodicals archive ?

Belowground annual ring growth coordinates with aboveground phenology and timing of carbon storage in two tallgrass prairie forb species.

Mowing Frequency Influences Number of Flowering Stems but not Population Age Structure of Asclepias viridis, an Important Monarch Host Plant

Gluing of star-sawn triangular profiles into form-stable products with vertical annual rings. Eur.

Characterizing Star-sawn Pattern--Produced and Orthogonally Glued Specimens of Southern Pine

Observations of annual rings on scales and otoliths were conducted by using stereo microscope (Leica MZ75, Germany) and photographs of scales and otoliths were taken and saved (Leica DFC300 FX).

Precision of age estimations from scales, otoliths, vertebrae, opercular bones and cleithra of two loaches, Misgurnus anguillicaudatus and Paramisgurnus dabryanus

Aydin and Sen (2002) reported that they observed the most clear annual rings on otoliths in their study on age relationships between right and left sides of the same bony structures of C.

Age Determination of Red-Spotted Trout (Salmo macrostigma) Inhabiting Munzur Stream Turkey

At a level of 95%, the differences were revealed between the shell heights of the clams collected from the northwestern and southern coasts (shells with 4 and 5 annual rings), clams sampled from the northwestern and eastern coasts (shells with 4 and 5 annual rings), and clams sampled from the northern and eastern coasts (shells with 3 annual rings).

Habitat preferences and growth of Ruditapes bruguieri (Bivalvia: Veneridae) at the northern boundary of its range

The annual ring properties of the wood samples seem to be an insignificant factor affecting the colour changes during the thermal compressing.

Colour characteristics of pine wood affected by thermal compressing/Caracteristicas da cor da madeira de pinus afetada por compressao termica

We counted and measured the annual rings of each cored tree using a compound dissecting microscope and a Velmex stage micrometer attached to a Metronics QC10 digital display and a computer running MeasureJ2X software (VoorTech.com, 2008) in order to determine age structure and growth patterns of stands at each study site.

Fire and the development of high-elevation pitch pine communities in Northeastern West Virginia

Using a Velmex [R] micrometer (precision 0.005 mm) under a binocular microscope at 40X to count annual rings, we determined that the individual's oldest living stem was at least 370 years old.

Persistence at the tree line: old trees as opportunists

"Pull away the seaweed and the annual rings of the tree trunks are still clearly visible.

'Our heritage trees at risk from weather and human vagaries' To some they are simply humble trees - but a movement is growing to recognise these natural monuments as being just as historically valuable as any castle or stately home. Sally Williams reports

The last few cell rows of libriform wood fibres at the border of the annual rings are more strongly lignified than the weakly lignified libriform wood fibres of the early wood.

Micromorphological Studies on the Degradation of Commercial Woods by Brown Rot Fungus. Coniophora Putana

annual rings, pith rays, arrangement of wood fibres and so on.

Wood texture influence on temperature fields

In his research, Muscheler worked to reconstruct previous changes in solar activity by studying how cosmogenic isotopes, for example of beryllium-10 and carbon-14, have been stored in both ice cores and annual rings in trees.