Stevekane
Established Member
I think the curve in the rings indicates the outside, the curve being the circumference of the tree and its what causes cupping in boards as it has a tendency to want to flatten out as it drys,,I think?
Steve
The don't make stuff/timber/lumber like they used to
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Steve
mudman
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Oh pipper of course. Tighter curve towards the middle. So better conditions more conducive to growth early in its life.
No same or more growth spread around a larger circumference!
mudman
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Don't think it works like that. A tree doesn't create a fixed amount of new wood each year and spread it around.
I did a bit of a search, check out this link: https://www.internationalpaper.com/docs/default-source/english/sustainability/treerings.pdf?sfvrsn=2
Interestingly they also give the example of trees getting crowded later in life causing narrower rings.
Sgian Dubh
Established Member
To see that many growth rings in a quarter sawn board that's ~100 mm wide indicates somewhat unusually slow growth equating to an average increase in the trunk's girth of a bit over 2 mm per annum, i.e. 104 (growth rings) / 100 (mm) = 1.04 mm from the beginning of one growth ring to the beginning of the next. Doubling 1.04 mm = 2.08 mm indicating the approximate girth increase. It's not obvious to me that the wood shows growth stress of some sort, so perhaps the board came from a tree that grew in an area with a short growing season, e.g., a high latitude where summers are are short. That's obviously just a guess.
A rough and ready method to non-invasively estimate tree age in mild temperate climates where the tree is 30 to 50 years old or more is to measure the girth (circumference) at approximately chest height. Each 25 mm (1 inch) of circumferential length counts as one year. πd (pi X diameter) calculates the circumference of a circle. The sum assumes a typical tree will increase its diameter by about 9 mm (3/8”±) each year, i.e., from one spring growth onset to the following spring growth onset. Annual ring spacing, on this assumption, averages, 4.5 mm (3/16”).
As to forest cover in Great Britain, there never has been 100% cover, coast to coast north/south and east/west caused by factors such as Ice Ages and cold at higher altitude. It is estimated at its peak, between 5000 and 3000 years BC, about 75 percent of the land was covered with forest. Great Britain in this discussion specifically means the biggest of the British Isles excluding Ireland. Since then humans, being the inveterate tinkerers, tool makers, tool users, food growers, and land managers we are have greatly reduced the forests. The first major assault by humans on the forests began during the Neolithic period, about 3500 years BC.
By about 500± BC clearing of the native forest to make way mainly for agriculture had reduced the wooded coverage of Great Britain to about 50 percent. What forest remained continued to decline until by about 1100 AD at which point there was only about 15 percent of wooded area. This forest was a mixture of wild or semi-organised, or fully managed as a resource for use by the human population. Since 1100 AD the proportion of forest coverage to open land in Great Britain has fluctuated between approximately 15 percent and, at the end of the 19th century, only 4 percent, which lead directly to the creation of the Forestry Commission in 1919 to manage the forests as a sustainable resource for the future needs of the nation. In 2005 the British government’s Department for Rural Affairs (defra) estimated roughly 12 percent of Britain’s land was forested or wooded Slainte.
A rough and ready method to non-invasively estimate tree age in mild temperate climates where the tree is 30 to 50 years old or more is to measure the girth (circumference) at approximately chest height. Each 25 mm (1 inch) of circumferential length counts as one year. πd (pi X diameter) calculates the circumference of a circle. The sum assumes a typical tree will increase its diameter by about 9 mm (3/8”±) each year, i.e., from one spring growth onset to the following spring growth onset. Annual ring spacing, on this assumption, averages, 4.5 mm (3/16”).
As to forest cover in Great Britain, there never has been 100% cover, coast to coast north/south and east/west caused by factors such as Ice Ages and cold at higher altitude. It is estimated at its peak, between 5000 and 3000 years BC, about 75 percent of the land was covered with forest. Great Britain in this discussion specifically means the biggest of the British Isles excluding Ireland. Since then humans, being the inveterate tinkerers, tool makers, tool users, food growers, and land managers we are have greatly reduced the forests. The first major assault by humans on the forests began during the Neolithic period, about 3500 years BC.
By about 500± BC clearing of the native forest to make way mainly for agriculture had reduced the wooded coverage of Great Britain to about 50 percent. What forest remained continued to decline until by about 1100 AD at which point there was only about 15 percent of wooded area. This forest was a mixture of wild or semi-organised, or fully managed as a resource for use by the human population. Since 1100 AD the proportion of forest coverage to open land in Great Britain has fluctuated between approximately 15 percent and, at the end of the 19th century, only 4 percent, which lead directly to the creation of the Forestry Commission in 1919 to manage the forests as a sustainable resource for the future needs of the nation. In 2005 the British government’s Department for Rural Affairs (defra) estimated roughly 12 percent of Britain’s land was forested or wooded Slainte.
This has cropped up before. Is that Australian mulberry ( Hedycarya angustifolia) or the mulberry we know (Morus nigra)
Jameshow
Established Member
I guess your talking about softwoods? Rings will be closer on hardwoods and also the further north you go?
Sgian Dubh
Established Member
Not specifically softwoods. The age estimating method I described can be used on both gymnosperms and angiosperms. It's as I said, rough and ready and the 'guesstimated' age requires a decent level of scepticism. What has surprised me somewhat is that I have used the method to estimate the age of trees whose date of germination are known to within a few decades, and results have quite often correlated reasonably accurately with the known planting or germination date. How much of that is down to simple coincidence I can't say because I've had results that were quite a number of years, even decades out from the known age (roughly) of the tree. And you are right to point out that local weather patterns or climate influences speed of growth, as does soil type, the tree's location such as hedgerow, open ground, forest, and so on. Also different tree species have different growth rates and typical lifespans.
Orraloon
Established Member
The common or garden verity with the big black berries. It's a bit of a weed around here.
Regards
John
The common or garden Australian variety. Ours has big black berries but it's not a weed. Two different trees.
