Sunday, October 21, 2007


At Exbury Gardens there is a Domesday Yew. Although very old, going back to the fourteenth Century, it certainly does not go back to the Domesday book in 1086. Also in the gardens is a tree that was felled in the storms of the 1990s on which the tree rings demonstrate that it was a foot in diameter at the time of the American Revolution. The greatest set of tree ring data comes from the Bristlecone Pines in the White Mountains of North America. History back to 7000 BC van be traced there.

What I want to know is whether it works at the equator where there is no winter.


Anonymous said...

Yes trees that I saw growing in the Caribbean had tree rings. But these rings just showed the wet and dry seasons. The decidious trees all lost their leaves in the dry season and then they grew again in the wet season. HOWEVER after a hurricane all the leaves could be stripped from the trees, and I do not know if the regrowth of new leaves after the hurricane produced another set of rings...
Dick Morris CLL W & W 13 del

justme said... I did a google search...

Assuming that my sources are accurate...I would guess, yes it some cases. It seems that it may depend on where around the equator they are growing, and to some extent, what type of trees they least in regard to how clear the rings are.

"Do trees which grow at the equator have growth lines?
The presence of rings in trees is due to the greater or smaller growth of the cells in the trunks. This growth depends on water disponibility, when there is low water disponibility, the size of the cells will be smaller as opposed to the bigger size of the cells when there is enough water. In some parts of the tropics, there are two seasons, the rainy season and the dry season. Trees growing in these regions will have rings; however, trees growing in rain forests where humidity is always present, they will not have those rings."

“Teak (Tectona grandis L.) is one out of few tropical tree species that forms clear annual growth rings. This was already noticed by Brandis about 150 years ago, and also by Coster during the 20s and 30s of this century. Teak trees can reach an age of 400 years. The durable wood has excellent physical properties and has been used for building material since prehistory. These facts demonstrate the suitability of teak for dendrochronological research."

(Teak grows only within a very narrow band around the world, within 20 degrees of the equator.)